TWI427273B - Distance-measuring device of increasing a signal-to-noise ratio and method thereof - Google Patents
Distance-measuring device of increasing a signal-to-noise ratio and method thereof Download PDFInfo
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本發明係有關於一種測距裝置及其方法,更明確地說,係有關於一種可提高訊雜比之測距裝置及其方法。The present invention relates to a distance measuring device and a method thereof, and more particularly to a distance measuring device and a method thereof for improving a signal to noise ratio.
在先前技術中,測距裝置係對待測物發射偵測光,並接收由待測物反射偵測光所產生之反射光。測距裝置可藉由量測偵測光往返測距裝置與待測物之間所需的時間,以推算測距裝置與待測物之間的距離。然而,由於當待測物表面之反射率較低時,待測物所產生之反射光之能量較低,而使得測距裝置易受到背景光(雜訊)之影響,而產生較大的量測誤差,造成使用者的不便。In the prior art, the ranging device emits detection light for the object to be measured, and receives the reflected light generated by the detection object to reflect the detected light. The distance measuring device can estimate the distance between the distance measuring device and the object to be tested by measuring the time required for detecting the light to and from the distance measuring device and the object to be tested. However, since the energy of the reflected light generated by the object to be tested is low when the reflectance of the surface of the object to be tested is low, the distance measuring device is susceptible to background light (noise), and a large amount is generated. Measuring the error, causing inconvenience to the user.
本發明提供一種可提高一測距裝置之訊雜比之方法。該測距裝置用來量測該測距裝置與一待測物之間之一待測距離。該待測距離大於一已知最短待測距離且小於一已知最長待測距離。該測距裝置具有一發光元件與一第一光感測元件。該發光元件用來發出一偵測光。該第一光感測元件用來根據一第一快門週期訊號,以感測並累積光之能量,來據以產生一第一光感測訊號。該方法包含該發光元件於一發光時間內,持續發出一偵測光射向該待測物,以產生一反射光、當該發光元件開始發出該偵測光後,經過一延遲時間後,切換該第一快門週期訊號於一第一感測時間內皆表示開啟,以使該第一光感測元件感測並累積該反射光之能量,並據以產生該第一光感測訊號、根據於該發光時間內該發光元件所發出之該偵測光之能量與該第一光感測訊號,以得到光往返該測距裝置與該待測物之一光飛行時間(Time of Flight,TOF),以及根據該光飛行時間,以得到該待測距離。該延遲時間係根據該已知最短待測距離所計算,以使該反射光於該延遲時間之後射至該第一光感測元件。The present invention provides a method for increasing the signal to noise ratio of a ranging device. The distance measuring device is configured to measure a distance to be measured between the distance measuring device and an object to be tested. The distance to be measured is greater than a known shortest distance to be measured and less than a known longest distance to be measured. The distance measuring device has a light emitting element and a first light sensing element. The illuminating element is configured to emit a detection light. The first light sensing component is configured to sense and accumulate energy of the light according to a first shutter period signal to generate a first light sensing signal. The method includes the illuminating element continuously emitting a detecting light to the object to be tested during a illuminating time to generate a reflected light, and after the illuminating element starts to emit the detecting light, after a delay time, switching The first shutter period signal is turned on for a first sensing time, so that the first light sensing component senses and accumulates the energy of the reflected light, and accordingly generates the first light sensing signal, according to The energy of the detected light emitted by the illuminating element and the first light sensing signal during the illuminating time to obtain light traveling time from the distance measuring device and the object to be tested (Time of Flight, TOF) ), and according to the flight time of the light, to obtain the distance to be measured. The delay time is calculated based on the known shortest distance to be measured such that the reflected light strikes the first light sensing element after the delay time.
本發明另提供一種可提高一測距裝置之訊雜比之方法。該測距裝置用來量測該測距裝置與一待測物之間之一待測距離。該待測距離大於一已知最短待測距離且小於一已知最長待測距離。該測距裝置具有一發光元件、一第一光感測元件與一第二光感測元件。該發光元件用來發出一偵測光。該第一光感測元件用來根據一第一快門週期訊號,以感測並累積光之能量,來據以產生一第一光感測訊號。該第二光感測元件用來根據一第二快門週期訊號,以感測並累積光之能量,來據以產生一第二光感測訊號。該方法包含該發光元件於一發光時間內,持續發出一偵測光射向該待測物,以產生一反射光、當該發光元件開始發出該偵測光後,經過一延遲時間後,切換該第一快門週期訊號於一第一感測時間內皆表示開啟,以使該第一光感測元件感測並累積該反射光之能量,並據以產生該第一光感測訊號、當該第一光感測元件停止感測該反射光之後,切換該第二快門週期訊號於一第二感測時間內皆表示開啟,以使該第二光感測元件感測並累積該背景光之能量,並據以產生該第二光感測訊號、根據該第一光感測訊號與該第二光感測訊號之比例,以得到光往返該測距裝置與該待測物之一光飛行時間,以及根據該光飛行時間,以得到該待測距離。該延遲時間係根據該已知最短待測距離所計算,以使該反射光於該延遲時間之後射至該第一光感測元件。The present invention further provides a method for increasing the signal to noise ratio of a ranging device. The distance measuring device is configured to measure a distance to be measured between the distance measuring device and an object to be tested. The distance to be measured is greater than a known shortest distance to be measured and less than a known longest distance to be measured. The distance measuring device has a light emitting element, a first light sensing element and a second light sensing element. The illuminating element is configured to emit a detection light. The first light sensing component is configured to sense and accumulate energy of the light according to a first shutter period signal to generate a first light sensing signal. The second light sensing component is configured to sense and accumulate energy of the light according to a second shutter period signal to generate a second light sensing signal. The method includes the illuminating element continuously emitting a detecting light to the object to be tested during a illuminating time to generate a reflected light, and after the illuminating element starts to emit the detecting light, after a delay time, switching The first shutter period signal is turned on for a first sensing time, so that the first light sensing component senses and accumulates the energy of the reflected light, and accordingly generates the first light sensing signal. After the first light sensing component stops sensing the reflected light, switching the second shutter period signal to turn on in a second sensing time, so that the second light sensing component senses and accumulates the backlight. Energy, and according to the second light sensing signal, according to the ratio of the first light sensing signal and the second light sensing signal, to obtain light to and from the distance measuring device and the object to be tested Flight time, and according to the flight time of the light, to obtain the distance to be measured. The delay time is calculated based on the known shortest distance to be measured such that the reflected light strikes the first light sensing element after the delay time.
本發明另提供一種可提高一測距裝置之訊雜比之方法。該測距裝置用來量測該測距裝置與一待測物之間之一待測距離。該待測距離大於一已知最短待測距離且小於一已知最長待測距離。該測距裝置具有一發光元件與一光感測組。該發光元件用來根據一發光週期訊號以發出一偵測光。該光感測組用來根據一第一快門週期訊號,感測並累積光之能量,以產生一第一光感測訊號,且用來根據該第二快門週期訊號,感測並累積光之能量,以產生一第二光感測訊號。該方法包含以一偵測頻率切換該發光週期訊號表示開啟與關閉,以使該發光元件切換於一發光時間內發出該偵測光射向該待測物,來產生一反射光,並於一不發光時間內停止發射該偵測光、每當該發光元件開始發出該偵測光後,經過一延遲時間後,切換該第一快門週期訊號於一第一感測時間內皆表示開啟,以使該光感測組感測並累積該反射光之能量,並據以產生該第一光感測訊號、於該第一感測時間後,切換該第二快門週期訊號於一第二感測時間內皆表示開啟,以使該光感測組感測並累積該反射光之能量,並據以產生該第二光感測訊號、根據該第一光感測訊號與該第二光感測訊號之比例,以得到光往返該測距裝置與該待測物之一光飛行時間,以及根據該光飛行時間,以得到該待測距離;該第一快門週期訊號與該發光週期訊號大致為同相。該第二快門週期訊號與該第一快門週期訊號大致為反相。該延遲時間係根據該已知最短待測距離所計算,以使該反射光於該延遲時間之後射至該光感測組。The present invention further provides a method for increasing the signal to noise ratio of a ranging device. The distance measuring device is configured to measure a distance to be measured between the distance measuring device and an object to be tested. The distance to be measured is greater than a known shortest distance to be measured and less than a known longest distance to be measured. The distance measuring device has a light emitting element and a light sensing group. The illuminating element is configured to emit a detection light according to an illumination period signal. The light sensing group is configured to sense and accumulate energy of light according to a first shutter period signal to generate a first light sensing signal, and to sense and accumulate light according to the second shutter period signal. Energy to generate a second light sensing signal. The method includes: switching the illumination period signal to turn on and off at a detection frequency, so that the illumination element is switched to emit a detection light to the object to be tested during a illumination time to generate a reflected light, and Stopping the detection of the detected light in the non-lighting time, and after the delay time elapses after the light emitting element starts to emit the detection light, switching the first shutter period signal to open in a first sensing time, Sensing the light sensing group and accumulating the energy of the reflected light, and generating the first light sensing signal, and switching the second shutter period signal to a second sensing after the first sensing time Turning on the time, the light sensing group senses and accumulates the energy of the reflected light, and generates the second light sensing signal according to the first light sensing signal and the second light sensing. a ratio of the signal to obtain a light flight time from the distance measuring device and the object to be tested, and according to the light flight time, to obtain the distance to be measured; the first shutter period signal and the lighting period signal are substantially In phase. The second shutter period signal is substantially opposite to the first shutter period signal. The delay time is calculated based on the known shortest distance to be measured, so that the reflected light is incident on the light sensing group after the delay time.
本發明另提供一種可提高訊雜比之測距裝置。該測距裝置用來量測該測距裝置與一待測物之間之一待測距離。該待測距離大於一已知最短待測距離且小於一已知最長待測距離。該測距裝置包含一發光元件、一第一光感測元件、一發光/感測控制電路,以及一距離計算電路。該發光元件用來發出一偵測光。該第一光感測元件用來根據一第一快門週期訊號,以感測並累積光之能量,來據以產生一第一光感測訊號。該發光/感測控制電路用來控制該發光元件於一發光時間內,持續發出該偵測光射向該待測物,以產生一反射光,並於該發光元件開始發出該偵測光後,經過一延遲時間後,切換該第一快門週期訊號於一第一感測時間內皆表示開啟,以使該第一光感測元件感測並累積該反射光之能量,來產生該第一光感測訊號。該發光/感測控制電路根據該已知最短待測距離計算該延遲時間,以使該反射光於該延遲時間之後射至該第一光感測元件。該距離計算電路用來根據於該發光時間內該發光元件所發出之該偵測光之能量與該第一光感測訊號,以得到光往返該測距裝置與該待測物之一光飛行時間,並根據該光飛行時間,產生一輸出訊號,代表該待測距離。The invention further provides a distance measuring device capable of improving the signal to noise ratio. The distance measuring device is configured to measure a distance to be measured between the distance measuring device and an object to be tested. The distance to be measured is greater than a known shortest distance to be measured and less than a known longest distance to be measured. The distance measuring device comprises a light emitting component, a first light sensing component, a light emitting/sensing control circuit, and a distance calculating circuit. The illuminating element is configured to emit a detection light. The first light sensing component is configured to sense and accumulate energy of the light according to a first shutter period signal to generate a first light sensing signal. The illuminating/sensing control circuit is configured to control the illuminating element to continuously emit the detecting light to the object to be tested during a illuminating time to generate a reflected light, and after the illuminating element starts to emit the detecting light After a delay time, switching the first shutter period signal to be turned on for a first sensing time, so that the first light sensing component senses and accumulates the energy of the reflected light to generate the first Light sensing signal. The illumination/sensing control circuit calculates the delay time according to the known shortest distance to be measured, so that the reflected light is incident on the first photo sensing element after the delay time. The distance calculating circuit is configured to: according to the energy of the detecting light emitted by the illuminating element and the first light sensing signal during the illuminating time, to obtain light traveling to and from the distance measuring device and the object to be tested. Time, and according to the flight time of the light, an output signal is generated, representing the distance to be measured.
本發明另提供一種可提高訊雜比之測距裝置。該測距裝置用來量測該測距裝置與一待測物之間之一待測距離。該待測距離大於一已知最短待測距離且小於一已知最長待測距離。該測距裝置包含一發光元件、一第一光感測元件、一第二光感測元件、一發光/感測控制電路,以及一距離計算電路。該發光元件用來發出一偵測光。該第一光感測元件用來根據一第一快門週期訊號,以感測並累積光之能量,來據以產生一第一光感測訊號。該第二光感測元件用來根據一第二快門週期訊號,以感測並累積光之能量,來據以產生一第二光感測訊號。該發光/感測控制電路用來控制該發光元件於一發光時間內,持續發出該偵測光射向該待測物,以產生一反射光,並於該發光元件開始發出該偵測光後,經過一延遲時間後,切換該第一快門週期訊號於一第一感測時間內皆表示開啟,以使該第一光感測元件感測並累積該反射光之能量,來據以產生該第一光感測訊號,且於當該第一光感測元件停止感測該反射光之後,切換該第二快門週期訊號於一第二感測時間內皆表示開啟,以使該第二光感測元件感測並累積該反射光之能量,來據以產生該第二光感測訊號。該發光/感測控制電路根據該已知最短待測距離計算該延遲時間,以使該反射光於該延遲時間之後射至該第一光感測元件。該距離計算電路用來根據於該第一光感測訊號與該第二光感測訊號之比例,以得到光往返該測距裝置與該待測物之一光飛行時間,並根據該光飛行時間,產生一輸出訊號,代表該待測距離。The invention further provides a distance measuring device capable of improving the signal to noise ratio. The distance measuring device is configured to measure a distance to be measured between the distance measuring device and an object to be tested. The distance to be measured is greater than a known shortest distance to be measured and less than a known longest distance to be measured. The distance measuring device comprises a light emitting component, a first light sensing component, a second light sensing component, a light emitting/sensing control circuit, and a distance calculating circuit. The illuminating element is configured to emit a detection light. The first light sensing component is configured to sense and accumulate energy of the light according to a first shutter period signal to generate a first light sensing signal. The second light sensing component is configured to sense and accumulate energy of the light according to a second shutter period signal to generate a second light sensing signal. The illuminating/sensing control circuit is configured to control the illuminating element to continuously emit the detecting light to the object to be tested during a illuminating time to generate a reflected light, and after the illuminating element starts to emit the detecting light After a delay time, switching the first shutter period signal to be turned on for a first sensing time, so that the first light sensing component senses and accumulates the energy of the reflected light, thereby generating the a first light sensing signal, and after the first light sensing component stops sensing the reflected light, switching the second shutter cycle signal to turn on in a second sensing time to enable the second light The sensing component senses and accumulates energy of the reflected light to generate the second light sensing signal. The illumination/sensing control circuit calculates the delay time according to the known shortest distance to be measured, so that the reflected light is incident on the first photo sensing element after the delay time. The distance calculation circuit is configured to obtain a light flight time from the distance measuring device and the object to be tested according to the ratio of the first light sensing signal to the second light sensing signal, and fly according to the light Time, generating an output signal representing the distance to be measured.
本發明另提供一種可提高訊雜比之測距裝置。該測距裝置用來量測該測距裝置與一待測物之間之一待測距離。該待測距離大於一已知最短待測距離且小於一已知最長待測距離。該測距裝置包含一發光元件、一光感測組、一發光/感測控制電路,以及一距離計算電路。該發光元件用來發出一偵測光。該光感測組用來根據一第一快門週期訊號,感測並累積光之能量,以產生一第一光感測訊號,且用來根據該第二快門週期訊號,感測並累積光之能量,以產生一第二光感測訊號。該發光/感測控制電路用來以一偵測頻率切換該發光週期訊號表示開啟與關閉,以使該發光元件切換於一發光時間內發出該偵測光射向該待測物,來產生一反射光,並於一不發光時間內停止發射該偵測光。每當該發光元件開始發出該偵測光後,經過一延遲時間後,該發光/感測控制電路切換該第一快門週期訊號於一第一感測時間內皆表示開啟,以使該光感測組感測並累積該反射光之能量,來據以產生該第一光感測訊號,且於該第一感測時間後,該發光/感測控制電路切換該第二快門週期訊號於一第二感測時間內皆表示開啟,以使該光感測組感測並累積該反射光之能量,來據以產生該第二光感測訊號。該第一快門週期訊號與該發光週期訊號大致為同相。該第二快門週期訊號與該第一快門週期訊號大致為反相。該發光/感測控制電路根據該已知最短待測距離計算該延遲時間,以使該反射光於該延遲時間之後射至該光感測組。該距離計算電路用來根據於該第一光感測訊號與該第二光感測訊號之比例,以得到光往返該測距裝置與該待測物之一光飛行時間,並根據該光飛行時間,產生一輸出訊號,代表該待測距離。The invention further provides a distance measuring device capable of improving the signal to noise ratio. The distance measuring device is configured to measure a distance to be measured between the distance measuring device and an object to be tested. The distance to be measured is greater than a known shortest distance to be measured and less than a known longest distance to be measured. The distance measuring device comprises a light emitting component, a light sensing group, a light emitting/sensing control circuit, and a distance calculating circuit. The illuminating element is configured to emit a detection light. The light sensing group is configured to sense and accumulate energy of light according to a first shutter period signal to generate a first light sensing signal, and to sense and accumulate light according to the second shutter period signal. Energy to generate a second light sensing signal. The illuminating/sensing control circuit is configured to switch the illuminating period signal to be turned on and off at a detecting frequency, so that the illuminating element is switched to emit a light to the object to be tested during a illuminating time to generate a The light is reflected and the detection of the light is stopped during a non-lighting time. When the illuminating element starts to emit the detecting light, after a delay time, the illuminating/sensing control circuit switches the first shutter period signal to be turned on for a first sensing time to make the light sensation The measuring group senses and accumulates the energy of the reflected light to generate the first light sensing signal, and after the first sensing time, the lighting/sensing control circuit switches the second shutter period signal to The second sensing time is turned on to enable the light sensing group to sense and accumulate the energy of the reflected light to generate the second light sensing signal. The first shutter period signal is substantially in phase with the illumination period signal. The second shutter period signal is substantially opposite to the first shutter period signal. The illumination/sensing control circuit calculates the delay time according to the known shortest distance to be measured, so that the reflected light is incident on the light sensing group after the delay time. The distance calculation circuit is configured to obtain a light flight time from the distance measuring device and the object to be tested according to the ratio of the first light sensing signal to the second light sensing signal, and fly according to the light Time, generating an output signal representing the distance to be measured.
請參考第1圖。第1圖係為說明根據本發明之第一實施例之測距裝置100之示意圖。如第1圖所示,測距裝置100與待測物O1 之間之距離為D,而測距裝置100即為測量待測距離D。測距裝置100包含一發光/感測控制電路110、一發光元件120、一光感測組130、一距離計算電路140、一背景計算電路150、一頻率調整電路160,以及一聚光模組170。Please refer to Figure 1. Fig. 1 is a schematic view showing a distance measuring device 100 according to a first embodiment of the present invention. As shown in FIG. 1 , the distance between the distance measuring device 100 and the object to be tested O1 is D, and the distance measuring device 100 measures the distance D to be measured. The distance measuring device 100 includes a light emitting/sensing control circuit 110, a light emitting element 120, a light sensing group 130, a distance calculating circuit 140, a background calculating circuit 150, a frequency adjusting circuit 160, and a collecting module. 170.
發光/感測控制電路110,用來產生一發光週期訊號SLD 、快門週期訊號SST1 與SST2 、一階段訊號SP 、一偵測頻率訊號SFQ ,以及一讀取訊號SRE 。發光週期訊號SLD 、快門週期訊號SST1 與SST2 具有相同週期(頻率),且其頻率大小係由偵測頻率訊號SFQ 所決定。偵測頻率訊號SFQ 指示發光週期訊號SLD 、快門週期訊號SST1 與SST2 之頻率,意即當一裝置接收到偵測頻率訊號SFQ 時,可以得知發光週期訊號SLD 、快門週期訊號SST1 與SST2 之頻率。發光週期訊號SLD 大致上與快門週期訊號SST1 同相;發光週期訊號SLD 大致上與快門週期訊號SST2 反相。The illumination/sensing control circuit 110 is configured to generate an illumination period signal S LD , shutter period signals S ST1 and S ST2 , a phase signal S P , a detection frequency signal S FQ , and a read signal S RE . The illumination period signal S LD and the shutter period signals S ST1 and S ST2 have the same period (frequency), and the frequency is determined by the detection frequency signal S FQ . The detection frequency signal S FQ indicates the frequency of the illumination period signal S LD and the shutter period signals S ST1 and S ST2 , that is, when a device receives the detection frequency signal S FQ , the illumination period signal S LD and the shutter period can be known. The frequency of the signals S ST1 and S ST2 . The illumination period signal S LD is substantially in phase with the shutter period signal S ST1 ; the illumination period signal S LD is substantially opposite to the shutter period signal S ST2 .
發光元件120可為一發光二極體(Light-Emitting Diode,LED)。發光元件120根據發光週期訊號SLD ,以發射偵測光LID 射至待測物。舉例而言,當發光週期訊號SLD 代表「發光」時,發光元件120發射偵測光LID ;反之,當發光週期訊號SLD 代表「不發光」時,發光元件120不發射偵測光LID 。The light emitting element 120 can be a Light-Emitting Diode (LED). The light-emitting element 120 emits the detection light L ID to the object to be tested according to the light-emitting period signal S LD . For example, when the illuminating period signal S LD represents "lighting", the illuminating element 120 emits the detecting light L ID ; otherwise, when the illuminating period signal S LD represents "no illuminating", the illuminating element 120 does not emit the detecting light L. ID .
聚光模組170用來將待測物反射偵測光LID 所產生之反射光LRD 匯聚於光感測組130。The concentrating module 170 is configured to converge the reflected light L RD generated by the object to be detected by the detection light L ID to the light sensing group 130.
光感測組130,可為電荷耦合元件(Charge Coupled Device,CCD)或互補式金氧半導體(Complementary Metal-Oxide-Semiconductor,CMOS)感光元件。光感測組130用來根據快門週期訊號SST1 ,感測並累積偵測光LID 被待測物反射所產生之反射光LRD 之能量,以產生光感測訊號SLS1 ,並根據讀取訊號SRE ,輸出光感測訊號SLS1 。舉例而言,當快門週期訊號SST1 代表「開啟」時,光感測組130感測反射光LRD 之能量,以據以累積能量ER1 ;當快門週期訊號SST1 代表「關閉」時,光感測組130不感測反射光LRD 之能量,而不累積能量ER1 (電子)。當讀取訊號SRE 代表「讀取」時,光感測組130根據已經累積能量ER1 ,以輸出光感測訊號SLS1 。除此之外,光感測組130用來根據快門週期訊號SST2 ,感測並累積偵測光LID 被待測物反射所產生之反射光LRD 之能量,以產生光感測訊號SLS2 ,並根據讀取訊號SRE ,輸出光感測訊號SLS2 。舉例而言,當快門週期訊號SST2 代表「開啟」時,光感測組130感測反射光LRD 之能量,以據以累積能量ER2 ;當快門週期訊號SST2 代表「關閉」時,光感測組130不感測反射光LRD 之能量,而不累積能量ER2 。當讀取訊號SRE 代表「讀取」時,光感測組130根據已經累積能量ER2 ,以輸出光感測訊號SLS2 。其中當讀取訊號SRE 代表「讀取」時,在光感測組130輸出光感測訊號SLS1 與SLS2 之後,光感測組130會重置已累積能量ER1 與ER2 (意即光感測組130會清除所累積能量)。The light sensing group 130 can be a Charge Coupled Device (CCD) or a Complementary Metal-Oxide-Semiconductor (CMOS) photosensitive element. The light sensing group 130 is configured to sense and accumulate the energy of the reflected light L RD generated by the reflected light L ID reflected by the object to be detected according to the shutter period signal S ST1 to generate the light sensing signal S LS1 , and according to the reading take signal S RE, the output light sensing signal S LS1. For example, when the shutter period signal S ST1 represents "on", the light sensing group 130 senses the energy of the reflected light L RD to accumulate energy E R1 ; when the shutter period signal S ST1 represents "off", The light sensing group 130 does not sense the energy of the reflected light L RD without accumulating the energy E R1 (electron). When the read signal S RE stands for "read", the light sensing group 130 outputs the light sensing signal S LS1 according to the accumulated energy E R1 . In addition, the light sensing group 130 is configured to sense and accumulate the energy of the reflected light L RD generated by the reflected light L ID reflected by the object to be detected according to the shutter period signal S ST2 to generate the light sensing signal S. LS2 , and according to the read signal S RE , outputs the light sensing signal S LS2 . For example, when the shutter period signal S ST2 represents "on", the light sensing group 130 senses the energy of the reflected light L RD to accumulate energy E R2 ; when the shutter period signal S ST2 represents "off", The light sensing group 130 does not sense the energy of the reflected light L RD without accumulating the energy E R2 . When the read signal S RE stands for "read", the light sensing group 130 outputs the light sensing signal S LS2 according to the accumulated energy E R2 . When the read signal S RE stands for "read", after the light sensing group 130 outputs the light sensing signals S LS1 and S LS2 , the light sensing group 130 resets the accumulated energy E R1 and E R2 (meaning That is, the light sensing group 130 will clear the accumulated energy).
背景計算電路150,用來根據階段訊號SP ,以及光感測訊號SLS1 ,以輸出背景訊號SB 。The background calculation circuit 150 is configured to output the background signal S B according to the phase signal S P and the light sensing signal S LS1 .
頻率調整電路160,用來根據階段訊號SP ,以及光感測訊號SLS1 ,以輸出頻率控制訊號SFC 。距離計算電路140,用來根據階段訊號SP 、背景訊號SB 、光感測訊號SST1 與SST2 ,以及偵測頻率訊號SFQ ,以計算測距裝置100與待測物之間之待測距離D。The frequency adjustment circuit 160 is configured to output the frequency control signal S FC according to the phase signal S P and the light sensing signal S LS1 . The distance calculation circuit 140 is configured to calculate the distance between the ranging device 100 and the object to be tested according to the phase signal S P , the background signal S B , the light sensing signals S ST1 and S ST2 , and the detection frequency signal S FQ . Measure distance D.
當測距裝置100量測待測距離D時,可分為「量測背景階段」、「調整頻率階段」,以及「計算距離階段」。以下將就各階段之運作原理作詳細地說明。When the distance measuring device 100 measures the distance D to be measured, it can be classified into a "measurement background phase", a "adjustment frequency phase", and a "calculation distance phase". The operation of each stage will be described in detail below.
請參考第2圖。第2圖係為說明測距裝置100於「量測背景階段」時之內部之控制訊號之波形圖。當測距裝置100進入「量測背景階段」時,測距裝置100此時主要用來量測單位時間內光感測組130所感測背景光LB 之能量,以使測距裝置100在「計算距離階段」時可減小背景光LB 的影響。發光/感測控制電路110會先產生代表「讀取」之讀取訊號SRE ,以先重置光感測組130已累積之能量。接著,發光/感測控制電路110會產生脈衝寬度為TB 之快門週期訊號SST1 。其中TB 係為「量測背景週期」。由於此時發光週期訊號SLD 代表「不發光」,發光元件120沒有發出偵測光LID 。因此光感測組130不會感測到待測物反射偵測光LID 所產生之反射光LRD 之能量,而是感測背景光LB 之能量,以據以累積能量EB 。在量測背景週期TB 之後,發光/感測控制電路110會產生代表「讀取」之讀取訊號SRE 且同時產生代表「量測背景」之階段訊號SP ,以使光感測組130根據累積能量EB ,而輸出光感測訊號SLS1 。同時,背景計算電路150根據偵測頻率訊號SFQ 、光感測訊號SST1 ,以輸出背景訊號SB 至距離計算電路140。其中背景訊號SB 之值係代表單位時間內光感測組130感測背景光LB 所累積之能量,可以下式表示:Please refer to Figure 2. Figure 2 is a waveform diagram showing the internal control signals of the distance measuring device 100 during the "measurement background phase". When the distance measuring device 100 enters the “measurement background phase”, the distance measuring device 100 is mainly used to measure the energy of the background light L B sensed by the light sensing group 130 per unit time, so that the distance measuring device 100 is “ background can be reduced stage when calculating the distance "B of the light L impact. The illumination/sensing control circuit 110 first generates a read signal S RE representative of "read" to first reset the accumulated energy of the light sensing group 130. Next, the illumination/sensing control circuit 110 generates a shutter period signal S ST1 having a pulse width of T B . The T B system is the “measurement background period”. Since the illumination period signal S LD represents "no illumination" at this time, the light-emitting element 120 does not emit the detection light L ID . Therefore, the light sensing group 130 does not sense the energy of the reflected light L RD generated by the object reflection detection light L ID , but senses the energy of the background light L B to accumulate the energy E B . After measuring the background period T B , the illumination/sensing control circuit 110 generates a read signal S RE representing “read” and simultaneously generates a phase signal S P representing the “measurement background” to enable the light sensing group. 130 outputs a light sensing signal S LS1 according to the accumulated energy E B . At the same time, the background calculation circuit 150 outputs the background signal S B to the distance calculation circuit 140 according to the detection frequency signal S FQ and the light sensing signal S ST1 . The value of the background signal S B represents the energy accumulated by the light sensing group 130 in the unit time to sense the background light L B , which can be expressed by the following formula:
SB =EB /TB ...(1);S B =E B /T B ...(1);
其中EB 即為光感測組130於量測背景週期TB 內感測背景光LB 所累積之總能量。Wherein E B is the total energy accumulated by the light sensing group 130 during the measurement background period T B to sense the background light L B .
請參考第3圖。第3圖係為說明測距裝置100於「計算距離階段」時之內部之控制訊號之波形圖。當測距裝置100進入「計算距離階段」時,測距裝置100此時主要用來藉由發光元件120以偵測頻率FC 之發光週期訊號SLD ,控制發光元件120,以發出偵測光LID ,並藉由光感測組130感測待測物O1 反射偵測光LID 所產生之反射光LRD ,以計算出光往返測距裝置100與待測物O1 之間的時間,而得到待測距離D。發光/感測控制電路110會先產生代表「讀取」之讀取訊號SRE ,以先重置光感測組130之已累積能量。接著,發光/感測控制電路110會在N個偵測週期TC1 ~TCN 內以偵測頻率FC ,產生快門週期訊號SST1 與SST2 ,以及發光週期訊號SLD ,以使快門週期訊號SST1 與SST2 在「開啟」與「關閉」之間交互切換,且讓發光週期訊號SLD 在「發光」與「不發光」之間交互切換,其中N代表正整數。偵測週期TC1 ~TCN 之時間長度皆等於偵測週期TC ,且偵測週期TC 係為偵測頻率FC 之倒數。在偵測週期TC1 ~TCN 中,發光週期訊號SLD 與快門週期訊號SST1 係大致為同相,且快門週期訊號SST1 與快門週期訊號SST2 大致為反相。更明確地說,在偵測週期TC1 ~TCN 中,當發光週期訊號SLD 代表「發光」時,快門週期訊號SST1 代表「開啟」,而快門週期訊號SST2 代表「關閉」;當發光週期訊號SLD 代表「不發光」時,快門週期訊號SST1 代表「關閉」,而快門週期訊號SST2 代表「開啟」。發光元件120會在每個偵測週期TC1 ~TCN 之前半週期,發出偵測光LID ;光感測組130會在每個偵測週期TC1 ~TCN 之前半週期,感測待測物反射偵測光LID 所產生之反射光LRD ,以累積能量ER1 ;且光感測組130會在每個偵測週期TC1 ~TCN 之後半週期,感測待測物反射偵測光LID 所產生之反射光LRD ,以累積能量ER2 。Please refer to Figure 3. Figure 3 is a waveform diagram showing the internal control signals of the distance measuring device 100 during the "calculation distance phase". When the distance measuring device 100 enters the "calculation distance phase", the distance measuring device 100 is mainly used to control the light emitting element 120 by the light emitting element 120 to detect the light emitting period signal S LD of the frequency F C to emit the detecting light. L ID, and by reflecting light generated by sensing analyte sensing set 130 O 1 L ID detecting light reflected light L RD, to calculate the round trip time between the light apparatus 100 and the distance measuring analyte O And get the distance D to be measured. The illumination/sensing control circuit 110 first generates a read signal S RE representative of "read" to first reset the accumulated energy of the light sensing group 130. Then, the illumination/sensing control circuit 110 detects the frequency F C in the N detection periods T C1 to T CN , generates the shutter period signals S ST1 and S ST2 , and the illumination period signal S LD to make the shutter period The signals S ST1 and S ST2 are switched between "on" and "off", and the illumination period signal S LD is switched between "lighting" and "non-lighting", where N represents a positive integer. The detection period T C1 ~ T CN is equal to the detection period T C , and the detection period T C is the reciprocal of the detection frequency F C . In the detection period T C1 ~T CN , the illumination period signal S LD is substantially in phase with the shutter period signal S ST1 , and the shutter period signal S ST1 and the shutter period signal S ST2 are substantially inverted. More specifically, in the detection period T C1 ~T CN , when the illumination period signal S LD represents "lighting", the shutter period signal S ST1 represents "on", and the shutter period signal S ST2 represents "off"; when the light-emitting period of the signal S LD representing "does not light" on behalf of the shutter cycle signal S ST1 "closed", and shutter cycle signal S ST2 stands for "open." The light-emitting component 120 emits the detection light L ID in a half cycle before each detection period T C1 ~ T CN ; the light sensing group 130 will sense the half cycle before each detection period T C1 ~ T CN The object reflects the reflected light L RD generated by the light L ID to accumulate the energy E R1 ; and the light sensing group 130 senses the reflection of the object to be detected during the second half of each detection period T C1 ~T CN The reflected light L RD generated by the light L ID is detected to accumulate energy E R2 .
在偵測週期TC1 ~TCN 之後,發光/感測控制電路110會產生代表「讀取」之讀取訊號SRE 且同時產生代表「計算距離」之階段訊號SP ,以使光感測組130根據於偵測週期TC1 ~TCN 之前半週期感測反射光LRD 所累積之能量ER1 與感測背景光LB 所累積之能量EB1 ,輸出光感測訊號SLS1 至距離計算電路140,以及根據於偵測週期TC1 ~TCN 之後半週期感測反射光LRD 所累積之能量ER2 與感測背景光LB 所累積之能量EB2 ,輸出光感測訊號SLS2 至距離計算電路140。此時,距離計算電路140根據偵測頻率訊號SFQ 、光感測訊號SLS1 與SSL2 ,以及背景訊號SB ,以計算該測距裝置100與待測物之間之待測距離D,其中光感測訊號SLS1 與SSL2 之值係為(ER1 +EB1 )與(ER2 +EB2 ),而偵測頻率訊號SFQ 之值係為偵測頻率FC 。以下將更進一步地說明計算待測距離D之原理。After detecting the period T C1 ~T CN , the illumination/sensing control circuit 110 generates a read signal S RE representing "read" and simultaneously generates a phase signal S P representing "calculated distance" to enable light sensing. The group 130 outputs the light sensing signal S LS1 to the distance according to the energy E R1 accumulated by the reflected light L RD and the energy E B1 accumulated by the sensing background light L B during the detection period T C1 ~T CN. The calculation circuit 140 outputs the light sensing signal S according to the energy E R2 accumulated by the reflected reflected light L RD and the energy E B2 accumulated by the sensing background light L B after the detection period T C1 ~ T CN LS2 to distance calculation circuit 140. At this time, the distance calculation circuit 140 calculates the distance D to be measured between the distance measuring device 100 and the object to be tested according to the detection frequency signal S FQ , the light sensing signals S LS1 and S SL2 , and the background signal S B . The values of the optical sensing signals S LS1 and S SL2 are (E R1 + E B1 ) and (E R2 + E B2 ), and the value of the detecting frequency signal S FQ is the detecting frequency F C . The principle of calculating the distance D to be measured will be further explained below.
由第3圖中可看出,光感測組130於發光元件120開始發出偵測光LID 後,經過時間TD ,開始感測到待測物O1 反射偵測光LID 所產生之反射光LRD 。換句話說,時間TD 即為偵測光LID 從發光元件120射至待測物之時間,加上反射光LRD 從待測物O1 反射至光感測組130之時間(意即光往返測距裝置100與待測物O1 之時間)。由於在偵測週期TC1 之前半週期中,光感測組130有感測到反射光LRD 而累積能量ER1 之時間係為[(TC /2)-TD ],又偵測光LID 之脈衝寬度係等於(TC /2),因此於偵測週期TC1 之後半週期中,光感測組130有感測到反射光LRD 而累積能量ER2 之時間,係等於偵測光LID 之脈波寬度減去光感測組130於偵測週期TC1 之前半週期中有感測到反射光LRD 之時間。也就是說,於偵測週期TC1 之後半週期中,光感測組130有感測到反射光LRD 而累積能量ER2 之時間,會等於往返時間TD 。在偵測週期TC1 ~TCN 中,發光/感測控電路110係以「固定」的偵測頻率FC 產生發光週期訊號SLD 與快門週期訊號SST1 、SST2 ,因此在偵測週期TC2 ~TCN 中,每個前半週期中,光感測組130感測反射光LRD 而累積能量ER1 之時間皆會等於[(TC /2)-TD ],且每個後半 週期中,光感測組130感測反射光LRD 而累積能量ER2 之時間皆會等於TD 。如此一來,累積能量ER1 與ER2 之比值係等於[(TC /2)-TD ]/TD 。因此,往返時間TD 與光感測訊號ST1 與ST2 、偵測頻率FC ,以及背景訊號SB 之關係可由下式表示:TD =(TC /2)×[ER2 /(ER1 +ER2 )]=[1/(2×FC )]×[(SLS2 -EB2 )/(SLS1 -EB1 +SLS2 -EB2 )]=[1/(2×FC )]×[(SLS2 -EB2 )/(SLS1 -EB1 +SLS2 -EB2 )]=[1/(2×FC )]×[(SLS2 -SB /(2×FC ))/(SLS1 +SLS2 -SB /FC )]...(2);由於往返時間TD 係為光往返測距裝置100與待測物O1 之待測距離D之時間,因此待測距離D可以下式表示:D=TD ×C/2=[C/(4×FC )]×[(SLS2 -SB /(2×FC ))/(SLS1 +SLS2 -SB /FC )]...(3);其中C代表光速、N代表於計算距離階段內偵測週期之數目。As can be seen from Figure 3, the light sensing detector group 130 120 begins to emit light after the light emitting element L ID, the elapsed time T D, start the sensed analyte O 1 L ID detecting light reflected arising Reflected light L RD . In other words, the time T D is the time when the detected light L ID is emitted from the light emitting element 120 to the object to be tested, and the time when the reflected light L RD is reflected from the object to be tested O 1 to the light sensing group 130 (ie, The time between the optical reciprocating distance measuring device 100 and the object to be tested O 1 ). Since the light sensing group 130 senses the reflected light L RD and the accumulated energy E R1 is [(T C /2)-T D ] in the half cycle before the detection period T C1 , the light is detected again. The pulse width of the L ID is equal to (T C /2), so in the half cycle after the detection period T C1 , the light sensing group 130 senses the reflected light L RD and accumulates the energy E R2 , which is equal to the detection. The pulse width of the photometric L ID is subtracted from the time during which the photo-sensing group 130 senses the reflected light L RD in the half cycle before the detection period T C1 . That is, during the second half of the detection period T C1 , the photo sensing group 130 senses the reflected light L RD and accumulates the energy E R2 , which is equal to the round trip time T D . In the detection period T C1 ~T CN , the illumination/sensing control circuit 110 generates the illumination period signal S LD and the shutter period signals S ST1 , S ST2 with the "fixed" detection frequency F C , thus detecting the period T In C2 ~ T CN , in each of the first half cycles, the light sensing group 130 senses the reflected light L RD and the accumulated energy E R1 is equal to [(T C /2)-T D ], and each second half cycle The time that the light sensing group 130 senses the reflected light L RD and accumulates the energy E R2 will be equal to T D . As a result, the ratio of the cumulative energy E R1 to E R2 is equal to [(T C /2) - T D ] / T D . Therefore, the relationship between the round trip time T D and the light sensing signals S T1 and S T2 , the detection frequency F C , and the background signal S B can be expressed by the following equation: T D = (T C /2) × [E R2 / ( E R1 +E R2 )]=[1/(2×F C )]×[(S LS2 -E B2 )/(S LS1 -E B1 +S LS2 -E B2 )]=[1/(2×F C )]×[(S LS2 -E B2 )/(S LS1 -E B1 +S LS2 -E B2 )]=[1/(2×F C )]×[(S LS2 -S B /(2× F C )) / (S LS1 + S LS2 - S B / F C )] (2); since the round trip time T D is the distance D to be measured between the optical reciprocating distance measuring device 100 and the object to be tested O 1 The time, therefore, the distance D to be measured can be expressed by the following equation: D = T D × C / 2 = [C / (4 × F C )] × [(S LS2 - S B / (2 × F C )) / ( S LS1 +S LS2 -S B /F C )]...(3); where C is the speed of light and N is the number of detection periods in the calculation of the distance phase.
另外,值得注意的是,於「計算距離階段」,若N等於1,則光感測組130只有感測一個偵測週期的反射光LRD ,來累積能量ER1 與ER2 。此時若待測物O1 之反射率較低或待測距離D較長,則光感測組130可能會因為反射光LRD 之能量較低,而使得所累積之能量ER1 與能量ER2 太小,造成量測誤差較大。然而,若N越大,則光感測組130可於越多個偵測週期內,感測反射光LRD ,來累積能量ER1 與ER2 ,而使得能量ER1 與ER2 較大。如此一來,即使因待測物O1 之反射率較低或待測距離D較長,而造成反射光LRD 之能量較低,光感測組130仍可藉由多個偵測週期感測反射光LRD ,以提高累積能量ER1 與ER2 ,來減小量測誤差。In addition, it is worth noting that in the "calculation distance phase", if N is equal to 1, the light sensing group 130 only senses the reflected light L RD of one detection period to accumulate the energy E R1 and E R2 . At this time, if the reflectance of the object to be tested O 1 is low or the distance D to be measured is long, the light sensing group 130 may cause the accumulated energy E R1 and energy E because the energy of the reflected light L RD is low. R2 is too small, causing a large measurement error. However, if N is larger, the light sensing group 130 can sense the reflected light L RD for more than one detection period to accumulate the energy E R1 and E R2 , so that the energy E R1 and E R2 are larger. In this way, even if the reflectance of the object to be detected O 1 is low or the distance D to be measured is long, the energy of the reflected light L RD is low, the light sensing group 130 can still detect the cycle. The reflected light L RD is measured to increase the cumulative energy E R1 and E R2 to reduce the measurement error.
除此之外,在「計算距離階段」時,待測距離D係藉由式(2)之往返時間TD 推算而得。然而,若測距裝置100與待測物O1 之間之待測距離D太長,則有可能會導致往返時間TD 超過偵測週期TC 的二分之一。換句話說,於偵測週期TC1 之前半週期中,光感測組130無法感測到反射光LRD 來累積能量ER1 。如此一來,累積能量ER1 與ER2 之比值會不等於[(TC /2)-TD ]/TD ,而使得式(2)無法成立,而造成距離計算電路140無法透過式(3)計算出正確的待測距離D。因此,在計算距離階段之前,測距裝置100可先於「調整頻率階段」時,調整偵測週期TC (意即調整偵測頻率FC ),以確保在「計算距離階段」內之往返時間TD 小於偵測週期TC 的二分之一,而使距離計算電路140可透過式(3)計算出正確的待測距離D。In addition, in the "calculation distance phase", the distance D to be measured is derived from the round trip time T D of the equation (2). However, if the distance D to be measured between the distance measuring device 100 and the object to be tested O 1 is too long, it is possible to cause the round trip time T D to exceed one-half of the detection period T C . In other words, in the first half cycle of the detection period T C1 , the light sensing group 130 cannot sense the reflected light L RD to accumulate the energy E R1 . As a result, the ratio of the accumulated energy E R1 to E R2 may not be equal to [(T C /2)−T D ]/T D , so that the formula (2) cannot be established, and the distance calculation circuit 140 is not transparent ( 3) Calculate the correct distance D to be measured. Therefore, before the distance calculation phase, the distance measuring device 100 can adjust the detection period T C (ie, adjust the detection frequency F C ) before the “adjustment frequency phase” to ensure the round trip in the “calculation distance phase”. The time T D is less than one-half of the detection period T C , and the distance calculation circuit 140 can calculate the correct distance D to be measured through the equation (3).
請參考第4圖。第4圖係為說明測距裝置100於「調整頻率階段」時之內部之控制訊號之波形圖。在如第4圖左半部所示,當測距裝置100進入「調整頻率階段」時,發光/感測控制電路110會先產生代表「讀取」之讀取訊號SRE ,以先重置光感測組130之已累積能量。然後,發光/感測控制電路110會同時產生脈衝寬度為(TC /2)之代表「發光」之發光週期訊號SLD 、與脈衝寬度為(TC /2)之代表「開啟」之快門週期訊號SST1 。最後,發光/感測控制電路110會產生代表「讀取」之讀取訊號SRE 與代表「調整頻率」之階段訊號SP ,而使得光感測組130,根據感測反射光LRD 而累積之能量ER 與背景光之能量EB ,而輸出光感測訊號SLS1 (等於ER +EB )。且頻率調整電路160會根據光感測訊號SLS1 以及背景訊號SB ,以輸出頻率控制訊號SFC 。由於當光往返待測距離D之往返時間TD 小於(TC /2)時,光感測組130感測到反射光LRD 所累積之能量ER 會大於零;而當光往返待測距離D之往返時間TD 大於(TC /2)時,光感測組130無法感測到反射光LRD ,而使累積之能量ER 等於零。其中能量ER 可由下式表示:Please refer to Figure 4. Fig. 4 is a waveform diagram showing the internal control signals of the distance measuring device 100 in the "adjustment frequency phase". As shown in the left half of FIG. 4, when the distance measuring device 100 enters the "adjustment frequency phase", the illumination/sensing control circuit 110 first generates a read signal S RE representing "read" to reset first. The accumulated energy of the light sensing group 130. Then, the light emitting / sensing control circuit 110 will also generate light emitting period signal S LD pulse width (T C / 2) of the representative of "emission", the pulse width (T C / 2) of representing "open" the shutter of Cycle signal S ST1 . Finally, the illumination/sensing control circuit 110 generates a read signal S RE representing "read" and a phase signal S P representing "adjusted frequency", so that the light sensing group 130 is based on the sensed reflected light L RD The accumulated energy E R is the energy E B of the background light, and the light sensing signal S LS1 (equal to E R + E B ) is output. The frequency adjustment circuit 160 controls the signal S FC according to the light sensing signal S LS1 and the background signal S B . Since the round-trip time T D of the light to and from the distance D to be measured is less than (T C /2), the light sensing group 130 senses that the energy E R accumulated by the reflected light L RD is greater than zero; When the round trip time T D of the distance D is greater than (T C /2), the light sensing group 130 cannot sense the reflected light L RD , and the accumulated energy E R is equal to zero. The energy E R can be expressed by the following formula:
ER =SLS1 -SB /(2×FC )...(4);E R =S LS1 -S B /(2×F C )...(4);
因此,當頻率調整電路160根據式(4),判斷累積能量ER 小於等於臨界能量ETH (臨界能量ETH 可設為零)時,代表光往返待測距離D之往返時間TD 大於(TC /2)。此時頻率調整電路160會輸出代表「降低」之頻率調整訊號SFC ,以使得發光/感測控制電路110降低偵測頻率FC (增加偵測週期TC ),並使發光/感測控制電路110重複上述之步驟,以判斷在降低偵測頻率FC 後,光往返待測距離D之往返時間TD 是否小於(TC /2)。當頻率調整電路160根據光感測訊號SLS1 與背景訊號SB ,判斷累積能量ER 大於臨界能量ETH 時,代表光往返待測距離D之往返時間TD 小於(TC /2)。此時頻率調整電路160會輸出代表「維持」之頻率調整訊號SFC ,以使得發光/感測控制電路110維持此時之偵測頻率FC ,並結束「調整頻率階段」。如此一來,藉由頻率調整電路160判斷累積能量ER 大於臨界能量ETH ,以決定是否調降偵測頻率FC ,發光/感測控制電路110最後所得到的偵測頻率FC ,可使光往返待測距離D之往返時間TD 小於(TC /2)。Therefore, when the frequency adjustment circuit 160 determines that the cumulative energy E R is less than or equal to the critical energy E TH (the critical energy E TH can be set to zero) according to the formula (4), the round trip time T D representing the distance from the light to the measured distance D is greater than ( T C /2). At this time, the frequency adjustment circuit 160 outputs a frequency adjustment signal S FC representing "decrease", so that the illumination/sensing control circuit 110 lowers the detection frequency F C (increased detection period T C ) and enables illumination/sensing control The circuit 110 repeats the above steps to determine whether the round trip time T D of the light to and from the distance D to be measured is less than (T C /2) after the detection frequency F C is lowered. When the frequency adjustment circuit 160 determines that the cumulative energy E R is greater than the critical energy E TH according to the light sensing signal S LS1 and the background signal S B , the round trip time T D representing the light to and from the distance D to be measured is less than (T C /2). At this time, the frequency adjustment circuit 160 outputs a frequency adjustment signal S FC representing "maintenance" so that the illumination/sensing control circuit 110 maintains the detection frequency F C at this time, and ends the "adjustment frequency phase". Thus, the frequency adjusting circuit 160 is determined by the accumulated energy greater than a threshold energy E R E TH, to decide whether to cut detection frequency F C, the light emitting detection frequency F C / sensing control circuit 110 finally obtained, can be The round trip time T D of the light to and from the distance D to be measured is less than (T C /2).
綜上所述,於「量測背景階段」內,測距裝置100可量測單位時間內光感測組130所感測之背景光,以使測距裝置100可計算出光感測組130於單位時間內根據背景光LB 所累積之能量;於「調整頻率階段」內,測距裝置100可反覆降低偵測頻率FC ,以確保光往返待測距離D之往返時間TD 小於(TC /2);於「計算距離階段」內,測距裝置100可根據於N個偵測週期TC1 ~TCN 內光感測組130感測反射光LRD 而輸出之光感測訊號SLS1 與SLS2 、背景訊號SB 、頻率訊號SFQ ,並利用式(3)以計算出待測距離D。也就是說,測距裝置100可根據光感測訊號SLS1 與SLS2 之間之比值,以計算出待測距離D,且測距裝置100可根據背景訊號SB 以校正光感測訊號SLS1 與SLS2 之間之比值,來修正背景光LB 之影響。如此,測距裝置100可減小背景光LB 的影響,且避免待測距離D過長或待測物之反射率太低而造成的量測誤差,而更正確的計算出待測距離D。In summary, in the "measurement background phase", the ranging device 100 can measure the background light sensed by the light sensing group 130 per unit time, so that the distance measuring device 100 can calculate the light sensing group 130 in units. According to the energy accumulated by the backlight L B in the time; in the "adjustment frequency phase", the distance measuring device 100 can repeatedly reduce the detection frequency F C to ensure that the round-trip time T D of the light to and from the distance D to be measured is less than (T C /2); in the "calculating distance phase", the distance measuring device 100 can output the light sensing signal S LS1 according to the N detecting period T C1 ~T CN internal light sensing group 130 sensing the reflected light L RD With S LS2 , background signal S B , frequency signal S FQ , and using equation (3) to calculate the distance D to be measured. That is, the distance measuring device 100 can calculate the distance D to be measured according to the ratio between the light sensing signals S LS1 and S LS2 , and the distance measuring device 100 can correct the light sensing signal S according to the background signal S B . The ratio between LS1 and S LS2 to correct the effect of backlight L B . Thus, the ranging device 100 can reduce the influence of background light L B, and to avoid measurement errors measured distance D is too long or the reflectance was too low to be measured it caused, and measured more accurately calculate the distance D .
請參考第5圖。第5圖係為說明根據本發明之第二實施例之測距裝置500之示意圖。發光/感測控制電路511、發光元件520、距離計算電路540、背景計算電路550、頻率調整電路560及聚光模組570之結構及工作原理分別與發光/感測控制電路110、發光元件120、距離計算電路140、背景計算電路150、頻率調整電路160及聚光模組170類似,故不再贅述。發光/感測控制模組510包含發光/感測控制電路511,以及一驅動電路512。驅動電路512用來根據發光/感測控制電路511所產生之快門週期訊號SST1 與SST2 ,以及讀取訊號SRE ,以產生快門開啟脈衝訊號SSOP1 與SSOP2 、快門關閉脈衝訊號SSCP1 與SSCP2 、重置脈衝訊號SRP1 與SRP2 、輸出脈衝訊號SOP1 與SOP2 。光感測組530包含兩個光感測元件531與532。光感測元件531用來根據快門開啟脈衝訊號SSOP1 與快門關閉脈衝訊號SSCP1 ,以感測背景光LB 或反射光LRD ,而累積能量;並根據輸出脈衝訊號SOP1 與累積之能量,以輸出光感測訊號SLS1 ;且光感測元件531會根據重置脈衝訊號SRP1 ,以重置已累積之能量。光感測元件532之結構以及工作原理與光感測元件531類似,故不再贅述。Please refer to Figure 5. Figure 5 is a schematic view showing a distance measuring device 500 according to a second embodiment of the present invention. The structure and working principle of the illumination/sensing control circuit 511, the light-emitting element 520, the distance calculation circuit 540, the background calculation circuit 550, the frequency adjustment circuit 560, and the concentrating module 570 are respectively combined with the illumination/sensing control circuit 110 and the illuminating element 120. The distance calculation circuit 140, the background calculation circuit 150, the frequency adjustment circuit 160, and the concentrating module 170 are similar, and therefore will not be described again. The illumination/sensing control module 510 includes a light/sensing control circuit 511 and a driving circuit 512. The driving circuit 512 is configured to generate the shutter-on pulse signals S SOP1 and S SOP2 and the shutter-off pulse signal S SCP1 according to the shutter period signals S ST1 and S ST2 generated by the illumination/sensing control circuit 511 and the read signal S RE . And S SCP2 , reset pulse signals S RP1 and S RP2 , output pulse signals S OP1 and S OP2 . Light sensing group 530 includes two light sensing elements 531 and 532. The light sensing component 531 is configured to accumulate energy according to the shutter-on pulse signal S SOP1 and the shutter-off pulse signal S SCP1 to sense the background light L B or the reflected light L RD ; and according to the output pulse signal S OP1 and the accumulated energy The light sensing signal S LS1 is output; and the light sensing element 531 resets the accumulated energy according to the reset pulse signal S RP1 . The structure and working principle of the light sensing element 532 are similar to those of the light sensing element 531, and therefore will not be described again.
請參考第6圖。第6圖係為說明驅動電路512根據快門週期訊號SST1 與SST2 ,以及讀取訊號SRE ,以產生之快門開啟脈衝訊號SSOP1 與SSOP2 、快門關閉脈衝訊號SSCP1 與SSCP2 、重置脈衝訊號SRP1 與SRP2 、輸出脈衝訊號SOP1 與SOP2 之示意圖。如第6圖所示,當快門週期訊號SST1 從代表「關閉」切換到代表「開啟」時,驅動電路512會觸發快門開啟脈衝訊號SSOP1 ;當快門週期訊號SST1 從代表「開啟」切換到代表「關閉」時,驅動電路512會觸發快門關閉脈衝訊號SSCP1 。當快門週期訊號SST2 從代表「關閉」切換到代表「開啟」時,驅動電路512會觸發快門開啟脈衝訊號SSOP2 ;當快門週期訊號SST2 從代表「開啟」切換到代表「關閉」時,驅動電路512會觸發快門關閉脈衝訊號SSCP2 。當讀取訊號SRE 代表「讀取」時,驅動電路512會先觸發輸出脈衝訊號SOP1 與SOP2 ,然後再觸發重置脈衝訊號SRP1 與SRP2 。Please refer to Figure 6. Figure 6 is a diagram illustrating the driving circuit 512 according to the shutter period signals S ST1 and S ST2 , and the read signal S RE to generate shutter-on pulse signals S SOP1 and S SOP2 , shutter-off pulse signals S SCP1 and S SCP2 , heavy Schematic diagram of pulse signals S RP1 and S RP2 and output pulse signals S OP1 and S OP2 . As shown in FIG. 6, when the shutter period signal S ST1 is switched from "off" to "on", the drive circuit 512 triggers the shutter-on pulse signal S SOP1 ; when the shutter period signal S ST1 is switched from "representing" When the representative is "off", the drive circuit 512 triggers the shutter close pulse signal S SCP1 . When the shutter cycle signal S ST2 is switched from "off" to "on", the drive circuit 512 triggers the shutter open pulse signal S SOP2 ; when the shutter cycle signal S ST2 is switched from "on" to "off", The drive circuit 512 triggers the shutter close pulse signal S SCP2 . When the read signal S RE stands for "read", the drive circuit 512 first triggers the output pulse signals S OP1 and S OP2 , and then triggers the reset pulse signals S RP1 and S RP2 .
請參考第7圖。第7圖係為說明本發明之光感測組530之結構之示意圖。光感測組530之結構與數位相機中所用之CMOS感光元件類似。光感測元件531包含開關SW11 、SW12 、SW13 與SW14 、感光二極體PD1 、電容C1 ,以及電晶體Q1 。當開關SW13 之控制端C接收到重置脈衝訊號SRPl 時,開關SW13 之第一端1會耦接至第二端2(開關SW13 導通),而使電容C1 透過開關SW13 耦接至電壓源VDD ,以將電壓VC1 重置為一預定電位(如電壓VDD )。感光二極體PD1 ,用來根據偵測光LID 被待測物O1 反射所產生之反射光LRD 之能量,以產生並累積電子數目NEl 之電子。當開關SW12 之控制端C接收到快門關閉脈衝訊號SSCPl 時,開關SW12 之第一端1會耦接至第二端2(開關SW12 導通),而使感光二極體PD1 之電子透過開關SW12 流向電容C1 ,而造成電壓VC1 之電位下降。開關SW11 ,用來根據快門開啟脈衝訊號SSOP1 ,以清除感光二極體PD1 之殘餘電子,而重置電子數目NE1 。更明確地說,當開關SW11 之控制端C接收到快門開啟脈衝訊號SSOP 時,此時開關SW11 之第一端1會耦接至第二端2(開關SW11 導通),而使得感光二極體PD1 透過開關SW11 耦接至電壓源VDD 。因此,感光二極體PD1 所累積之電子會透過開關SW11 流向電壓源VDD 。電晶體Q1 用來作為一電壓隨耦器(voltage follower)。因此,電晶體Q1 之第二端2之電位係隨著電晶體Q1 之控制端C(閘極)之電壓VC1 變化。當開關SW14 之控制端C接收到輸出脈衝訊號SOP1 時,開關SW14 之第一端1耦接至第二端2(開關SW14 導通)。因此開關SW14 會藉由電晶體Q1 (電壓隨耦器),根據電壓VC1 ,以輸出光感測訊號SLS1 。如此一來,藉由光感測訊號SLS1 ,根據電壓VC1 與預定電位(如VDD )之間的電位差,可計算出光感測元件531所累積之能量。光感測元件532包含開關SW21 、SW22 、SW23 與SW24 、感光二極體PD2 、電容C2 ,以及電晶體Q2 。光感測元件532之結構及工作原理與光感測元件531類似,故不再贅述。Please refer to Figure 7. Figure 7 is a schematic diagram showing the structure of the light sensing group 530 of the present invention. The structure of the light sensing group 530 is similar to that of a CMOS sensor used in a digital camera. Light sensing element 531 comprises a switch SW 11, SW 12, SW 13 and SW 14, the photosensitive diode PD 1, capacitor C 1, and the transistor Q 1. When the control terminal C of the switch SW 13 receives the reset pulse signal S RP1 , the first end 1 of the switch SW 13 is coupled to the second terminal 2 (the switch SW 13 is turned on), and the capacitor C 1 is transmitted through the switch SW 13 It is coupled to a voltage source V DD to reset the voltage V C1 to a predetermined potential (eg, voltage V DD ). The photodiode PD 1 is configured to generate and accumulate electrons of the electron number N El according to the energy of the reflected light L RD generated by the detection light L ID being reflected by the object O 1 . When the control terminal C of the switch SW 12 receives the shutter-off pulse signal S SCP1 , the first end 1 of the switch SW 12 is coupled to the second terminal 2 (the switch SW 12 is turned on), and the photodiode PD 1 is The electrons pass through the switch SW 12 to the capacitor C 1 , causing the potential of the voltage V C1 to drop. The switch SW 11 is configured to remove the residual electrons of the photodiode PD 1 according to the shutter-on pulse signal S SOP1 and reset the number of electrons N E1 . More specifically, when the control terminal C of the switch SW 11 receives the shutter-on pulse signal S SOP , the first end 1 of the switch SW 11 is coupled to the second terminal 2 (the switch SW 11 is turned on), photosensitive diode PD 1 through the switch SW 11 is coupled to a voltage source V DD. Therefore, electrons accumulated by the photodiode PD 1 flow through the switch SW 11 to the voltage source V DD . The transistor Q 1 is used as a voltage follower. Thus, the electrical potential of the transistor Q 12 of the second terminal voltage V C1 varies with the transistor Q control terminal C (gate) of the 1. When the control terminal C of the switch SW 14 receives the output pulse signal S OP1 , the first end 1 of the switch SW 14 is coupled to the second terminal 2 (the switch SW 14 is turned on). Therefore, the switch SW 14 outputs the light sensing signal S LS1 according to the voltage V C1 through the transistor Q 1 (voltage follower). In this way, by the photo sensing signal S LS1 , the energy accumulated by the photo sensing element 531 can be calculated according to the potential difference between the voltage V C1 and the predetermined potential (eg, V DD ). The light sensing element 532 includes switches SW 21 , SW 22 , SW 23 and SW 24 , a photodiode PD 2 , a capacitor C 2 , and a transistor Q 2 . The structure and working principle of the light sensing element 532 are similar to those of the light sensing element 531, and therefore will not be described again.
由於當發光感測控制電路511產生快門週期訊號SST1 與SST2 ,或讀取訊號SRE 時,驅動電路512會據以產生對應的控制訊號(快門開啟脈衝訊號SSOP1 與SSOP2 、快門關閉脈衝訊號SSCP1 與SSCP2 、重置脈衝訊號SRP1 與SRP2 、輸出脈衝訊號SOP1 與SOP2 ),而控制光感測組530之光感測元件531與532,以使得光感測組530可如同光感測組130運作。更明確地說,當快門週期訊號SST1 表示「開啟」時,光感測元件531可感測偵測光LID 被待測物O1 反射所產生之反射光LRD 之能量;當快門週期訊號SST2 表示「開啟」時,光感測元件532可感測偵測光LID 被待測物O1 反射所產生之反射光LRD 之能量。當讀取訊號SRE 表示「讀取」時,光感測元件531輸出光感測訊號SLS1 ,同時光感測元件531重置所累積之反射光之能量,且光感測元件532也輸出光感測訊號SLS2 ,同時光感測元件532重置所累積之反射光之能量。也就是說,測距裝置500可如同測距裝置100運作。因此,測距裝置500可藉由第2圖所說明之測距裝置100於「量測背景階段」之運作方法、第4圖所說明之測距裝置100於「調整頻率階段」之運作方法,以及第3圖所說明之測距裝置100於「計算距離階段」之運作方法,來正確地量測待測距離D。When the light-emitting sensing control circuit 511 generates the shutter period signals S ST1 and S ST2 or reads the signal S RE , the driving circuit 512 generates corresponding control signals (the shutter-on pulse signals S SOP1 and S SOP2 , and the shutter is closed). The pulse signals S SCP1 and S SCP2 , the reset pulse signals S RP1 and S RP2 , and the output pulse signals S OP1 and S OP2 ), and the light sensing elements 531 and 532 of the light sensing group 530 are controlled to enable the light sensing group The 530 can operate as the light sensing group 130. More specifically, when the shutter period signal S ST1 indicates "on", the light sensing element 531 can sense the energy of the reflected light L RD generated by the reflected light L ID reflected by the object O 1 ; When the signal S ST2 indicates "ON", the light sensing element 532 can sense the energy of the reflected light L RD generated by the detection light L ID being reflected by the object O 1 . When the read signal S RE indicates "read", the light sensing element 531 outputs the light sensing signal S LS1 while the light sensing element 531 resets the energy of the accumulated reflected light, and the light sensing element 532 also outputs The light sensing signal S LS2 , while the light sensing element 532 resets the energy of the accumulated reflected light. That is, the distance measuring device 500 can operate as the distance measuring device 100. Therefore, the distance measuring device 500 can operate the "measurement background phase" by the distance measuring device 100 illustrated in FIG. 2 and the "adjustment frequency phase" operation method of the distance measuring device 100 illustrated in FIG. And the operation method of the distance measuring device 100 described in FIG. 3 in the "calculation distance phase" to correctly measure the distance D to be measured.
請參考第8圖。第8圖係為說明根據本發明之第三實施例之測距裝置800之示意圖。發光/感測控制電路811、發光元件820、距離計算電路840、背景計算電路850、頻率調整電路860及聚光模組870之結構及工作原理分別與發光/感測控制電路110、發光元件120、距離計算電路140、背景計算電路150、頻率調整電路160及聚光模組170類似,故不再贅述。發光/感測控制模組810包含發光/感測控制電路811,以及一驅動電路812。驅動電路812用來根據發光/感測控制電路811所產生之快門週期訊號SST1 與SST2 ,以及讀取訊號SRE ,以產生快門開啟脈衝訊號SSOP 、快門關閉脈衝訊號SSCP1 與SSCP2 、重置脈衝訊號SRP1 與SRP2 、輸出脈衝訊號SOP1 與SOP2 。驅動電路812之工作原理與驅動電路512類似。與驅動電路512不同的是當快門週期訊號SST1 或快門週期訊號SST2 從代表「關閉」切換到代表「開啟」時,驅動電路812皆會觸發快門開啟脈衝訊號SSOP 。Please refer to Figure 8. Figure 8 is a schematic view showing a distance measuring device 800 according to a third embodiment of the present invention. The structure and working principle of the illuminating/sensing control circuit 811, the illuminating element 820, the distance calculating circuit 840, the background calculating circuit 850, the frequency adjusting circuit 860, and the concentrating module 870 are respectively combined with the illuminating/sensing control circuit 110 and the illuminating element 120. The distance calculation circuit 140, the background calculation circuit 150, the frequency adjustment circuit 160, and the concentrating module 170 are similar, and therefore will not be described again. The illumination/sensing control module 810 includes a lighting/sensing control circuit 811, and a driving circuit 812. The driving circuit 812 is configured to generate the shutter-on pulse signal SS OP and the shutter-off pulse signal S SCP1 and S SCP2 according to the shutter period signals S ST1 and S ST2 generated by the illumination/sensing control circuit 811 and the read signal S RE . , reset pulse signals S RP1 and S RP2 , output pulse signals S OP1 and S OP2 . The driving circuit 812 operates similarly to the driving circuit 512. Different from the driving circuit 512, when the shutter period signal S ST1 or the shutter period signal S ST2 is switched from the representative "off" to "on", the driving circuit 812 triggers the shutter-on pulse signal S SOP .
請參考第9圖。第9圖係為說明本發明之光感測組830之結構之示意圖。光感測組830之結構與工作原理與光感組530(包含光感測元件531與532)類似。與光感測組530不同的是,光感測組830省去開關SW21 與感光二極體PD2 。由於當測距裝置500於「量測背景階段」或於「調整頻率階段」時,只有利用到光感測組530之光感測元件531。換句話說,測距裝置500於「量測背景階段」或於「調整頻率階段」時,不會利用到開關SW21 與感光二極體PD2 。因此,利用光感測組830,測距裝置800於「量測背景階段」或於「調整頻率階段」時可如同測距裝置500運作。此外,由於在「計算距離階段」之偵測週期TC1 ~TCN 之內時,當快門週期訊號SST1 代表「開啟」時,快門週期訊號SST2 則代表「關閉」;當快門週期訊號SST2 代表「開啟」時,快門週期訊號SST1 則代表「關閉」。也就是說,快門週期訊號SST1 與SST2 不會同時代表「開啟」。因此,測距裝置800可於偵測週期TC1 ~TCN 之前半週期內(快門週期訊號SST1 代表「開啟」),利用光感測組830之感光二極體PD1 ,以累積電子;當快門週期訊號SST1 從「開啟」切為「關閉」時,感光二極體PD1 於前半週期內(快門週期訊號SST1 代表「開啟」)所累積之電子會流向電容C1 ,而使電壓VC1 之電位隨之變化;且測距裝置800可於偵測週期TC1 ~TCN 之後半週期內(快門週期訊號SST2 代表「開啟」),利用光感測組830之感光二極體PD1 ,以累積電子;當快門週期訊號SST2 從「開啟」切為「關閉」時,感光二極體PD2 於後半週期內(快門週期訊號SST2 代表「開啟」)所累積之電子會流向電容C2 ,而使電壓VC 2之電位隨之變化。因此,即使光感測組830只有一個感光二極體PD1 ,仍可如同光感測組530一樣運作。換句話說,測距裝置800於「計算距離階段」時也可如同測距裝置500運作。如此一來,由於測距裝置800於「量測背景階段」、「調整頻率階段」或「計算距離階段」時,皆可如同測距裝置500一樣運作,因此測距裝置800也可藉由第2圖所說明之測距裝置100於「量測背景階段」之運作方法、第4圖所說明之測距裝置100於「調整頻率階段」之運作方法,以及第3圖所說明之測距裝置100於「計算距離階段」之運作方法,來正確地量測待測距離D。Please refer to Figure 9. Figure 9 is a schematic diagram showing the structure of the light sensing group 830 of the present invention. The structure and working principle of the light sensing group 830 is similar to that of the light sensing group 530 (including the light sensing elements 531 and 532). Unlike the photo sensing group 530, the photo sensing group 830 omits the switch SW 21 and the photodiode PD 2 . Since the distance sensing device 500 is in the "measurement background phase" or the "adjustment frequency phase", only the light sensing component 531 of the light sensing group 530 is utilized. In other words, when the distance measuring device 500 is in the "measurement background phase" or in the "adjustment frequency phase", the switch SW 21 and the photodiode PD 2 are not used . Therefore, with the light sensing group 830, the distance measuring device 800 can operate as the distance measuring device 500 in the "measurement background phase" or in the "adjustment frequency phase". In addition, when the shutter period signal S ST1 represents "on" during the "calculation distance phase" detection period T C1 ~ T CN , the shutter period signal S ST2 represents "off"; when the shutter period signal S When ST2 stands for "ON", the shutter cycle signal S ST1 stands for "OFF". That is to say, the shutter cycle signals S ST1 and S ST2 do not simultaneously represent "on". Thus, the ranging device 800 may be a half-cycle (cycle shutter signal S ST1 representing "open") prior to the detection period T C1 ~ T CN, measured using a photosensitive group 830 of light-sensitive diode PD 1, to accumulate electrons; When the shutter period signal S ST1 is switched from "on" to "off", the electrons accumulated by the photodiode PD 1 during the first half period (the shutter period signal S ST1 represents "on") flow to the capacitor C 1 , so that The potential of the voltage V C1 changes accordingly; and the ranging device 800 can use the photosensitive diode of the light sensing group 830 during the second half cycle of the detection period T C1 ~ T CN (the shutter period signal S ST2 represents "on") The body PD 1 is used to accumulate electrons; when the shutter period signal S ST2 is switched from "on" to "off", the electrons accumulated by the photodiode PD 2 in the latter half cycle (the shutter period signal S ST2 represents "on") It will flow to the capacitor C 2 and the potential of the voltage V C 2 will change accordingly. Thus, even if the light sensing set 830 is only one photosensitive diode PD 1, still 530 as the light-sensing operation of the same group. In other words, the distance measuring device 800 can also operate as the distance measuring device 500 in the "calculation distance phase". In this way, since the distance measuring device 800 operates in the "measurement background phase", the "adjustment frequency phase" or the "calculation distance phase", it can operate like the distance measuring device 500, so the ranging device 800 can also be used by 2 is a method for operating the distance measuring device 100 in the "measurement background phase", the operation method of the distance measuring device 100 described in FIG. 4 in the "adjustment frequency phase", and the distance measuring device described in FIG. 100 in the "calculation distance phase" operation method to correctly measure the distance D to be measured.
此外,由於在光感測組530中,感光二極體PD2 所需之面積甚大,因此相較於光感測組530,光感測組830所需之面積較小,而使得測距裝置800之成本較低。In addition, since the area required for the photodiode PD 2 is very large in the photo sensing group 530, the area required for the photo sensing group 830 is smaller than that of the photo sensing group 530, so that the distance measuring device The cost of 800 is lower.
請參考第10圖與第11圖。第10圖與第11圖係為說明本發明之3D影像感測裝置1000之示意圖。3D影像感測裝置1000包含一測距裝置1090,以及一2D影像感測裝置1100。測距裝置1090包含一發光/感測控制電路1010、一發光元件1020、一光感測模組1030、一距離計算電路1040、一背景計算電路1050、一頻率調整電路1060,以及一聚光模組1070。2D影像感測裝置1100包含一影像感測控制電路1080,以及光感測模組1030,其中2D影像感測裝置1100與測距裝置1090共用光感測模組1030。發光/感測控制模組1010、發光元件1020、距離計算電路1040、背景計算電路1050、頻率調整電路1060之結構及工作原理分別與發光/感測控制電路110(或發光/感測控制電路511)、發光元件120(或發光元件520、820)、距離計算電路140(或距離計算電路540、840)、背景計算電路150(或背景計算電路550、850)、頻率調整電路160(或頻率調整電路560、860)類似。相較於測距裝置100、500、800,3D影像感測裝置1000之光感測模組1030包含M個光感測組CS1 ~CSM ,其中M為一正整數。光感測組CS1 ~CSM 之結構與工作原理與光感測組130或530類似。此外,光感測組CS1 ~CSM 受控於影像感測控制電路1080,用來感測一場景P(如第11圖所示),以得到一影像I。其中該場景P包含 M個反射點PN1 ~PNM ;該影像I包含M個畫素,且每個畫素包含兩個子畫素。場景P之每個反射點係對應於影像I中之一個畫素。Please refer to Figure 10 and Figure 11. 10 and 11 are schematic views illustrating a 3D image sensing device 1000 of the present invention. The 3D image sensing device 1000 includes a ranging device 1090 and a 2D image sensing device 1100. The distance measuring device 1090 includes a light-emitting/sensing control circuit 1010, a light-emitting element 1020, a light-sensing module 1030, a distance calculating circuit 1040, a background calculating circuit 1050, a frequency adjusting circuit 1060, and a collecting mode. The group 1070. The 2D image sensing device 1100 includes an image sensing control circuit 1080 and a light sensing module 1030. The 2D image sensing device 1100 shares the light sensing module 1030 with the ranging device 1090. The structure and working principle of the illumination/sensing control module 1010, the light-emitting element 1020, the distance calculation circuit 1040, the background calculation circuit 1050, and the frequency adjustment circuit 1060 are respectively combined with the illumination/sensing control circuit 110 (or the illumination/sensing control circuit 511). ), light-emitting element 120 (or light-emitting elements 520, 820), distance calculation circuit 140 (or distance calculation circuit 540, 840), background calculation circuit 150 (or background calculation circuit 550, 850), frequency adjustment circuit 160 (or frequency adjustment) Circuits 560, 860) are similar. Compared with the distance measuring device 100, 500, 800, the light sensing module 1030 of the 3D image sensing device 1000 includes M light sensing groups CS 1 ~ CS M , where M is a positive integer. The structure and working principle of the light sensing group CS 1 ~ CS M are similar to those of the light sensing group 130 or 530. In addition, the light sensing groups CS 1 to CS M are controlled by the image sensing control circuit 1080 for sensing a scene P (as shown in FIG. 11 ) to obtain an image I. The scene P includes M reflection points PN 1 ~ PN M ; the image I contains M pixels, and each pixel contains two sub-pixels. Each reflection point of the scene P corresponds to one of the pixels in the image I.
由於3D影像感測裝置1000之光感測模組1030包含M個光感測組CS1 ~CSM ,因此3D影像感測裝置1000可利用影像感測控制電路1080來控制光感測模組1030,以感測場景P之各反射點,進而得到影像I中之對應於各反射點之各畫素之兩個子畫素影像資料,且更可藉由測距裝置1090來測量場景P之每個反射點與3D影像感測裝置1000的距離,以得到每個畫素對應的距離資料。換句話說,3D影像感測裝置1000可感測場景P,以得到影像I,而影像I的解析度為M,且3D影像感測裝置1000所得到的每個畫素資料包含了兩個子畫素影像資料以及對應的距離(距離資料)。Since the light sensing module 1030 of the 3D image sensing device 1000 includes M light sensing groups CS 1 to CS M , the 3D image sensing device 1000 can control the light sensing module 1030 by using the image sensing control circuit 1080 . In order to sense the reflection points of the scene P, two sub-pixel image data corresponding to each pixel of each reflection point in the image I are obtained, and the scene P can be measured by the distance measuring device 1090. The distance between the reflection points and the 3D image sensing device 1000 is obtained to obtain the distance data corresponding to each pixel. In other words, the 3D image sensing device 1000 can sense the scene P to obtain the image I, and the resolution of the image I is M, and each pixel data obtained by the 3D image sensing device 1000 includes two sub-pixels. Pixel image data and corresponding distance (distance data).
舉例而言,設光感測模組1030之光感測組CS1 ~CSM 之結構如同光感測組530。也就是說,每個光感測組CS1 ~CSM 皆包含兩個光感測元件。其中光感測組CS1 包含光感測元件CSA1 與CSB1 ;光感測組CS2 包含光感測元件CSA2 與CSB2 ...光感測組CSM 包含光感測元件CSAM 與CSBM 。因此,3D影像感測裝置1000,可利用測距裝置1090之發光/感測控制電路1010產生第一快門週期訊號SST1 、第二快門週期訊號SST2 以及讀取訊號SRE ,來控制光感測模組CS1 ~CSM 。舉例而言,光感測組CSK 包含光感測元件CSAK 與CSBK 。當快門週期訊號SST1 代表「開啟」時,光感測元件CSAK 感測偵測光LID 被場景P之反射點PNK 反射所產生之反射光LRD 之能量,以據以累積能量ER1K ;當快門週期訊號SST1 代表「關閉」時,光感測元件CSAK 不感測偵測光LID 被場景P之反射點PNK 反射所產生之反射光LRD 之能量,而不累積能量ER1K 。當讀取訊號SRE 代表「讀取」時,光感測元件CSAK 根據已經累積能量ER1K ,以輸出光感測訊號SLS1K ;當快門週期訊號SST2 代表「開啟」時,光感測元件CSBK 感測偵測光LID 被場景P之反射點PNK 反射所產生之反射光LRD 之能量,以據以累積能量ER2K ;當快門週期訊號SST2 代表「關閉」時,光感測元件CSBK 不感測偵測光LID 被場景P之反射點PNK 反射所產生之反射光LRD 之能量,而不累積能量ER2K 。當讀取訊號SRE 代表「讀取」時,光感測元件CSBK 根據已經累積能量ER2K ,以輸出光感測訊號SLS2K 。除此之外,當讀取訊號SRE 代表「讀取」時,在光感測元件CSAK 與CSBK 輸出光感測訊號SLS1K 與SLS2K 之後,光感測元件CSAK 與CSBK 會重置已累積能量ER1K 與ER2K (意即光感測元件CSAK 與CSBK 會清除所累積能量)。For example, the light sensing groups CS 1 -CS M of the light sensing module 1030 are configured like the light sensing group 530. That is to say, each of the light sensing groups CS 1 to CS M includes two light sensing elements. The photo sensing group CS 1 includes photo sensing elements CSA 1 and CSB 1 ; the photo sensing group CS 2 includes photo sensing elements CSA 2 and CSB 2 ... the photo sensing group CS M includes a photo sensing element CSA M With CSB M. Therefore, the 3D image sensing device 1000 can use the illumination/sensing control circuit 1010 of the distance measuring device 1090 to generate the first shutter period signal S ST1 , the second shutter period signal S ST2 , and the read signal S RE to control the light sense. Test module CS 1 ~CS M . For example, the light sensing group CS K includes light sensing elements CSA K and CSB K . When the shutter period signal S ST1 represents "on", the light sensing element CSA K senses the energy of the reflected light L RD generated by the reflected light L ID reflected by the reflection point PN K of the scene P, to accumulate energy E. R1K ; when the shutter period signal S ST1 stands for "off", the light sensing element CSA K does not sense the energy of the reflected light L RD generated by the reflected light L ID reflected by the reflection point PN K of the scene P without accumulating energy E R1K . When the read signal S RE stands for "read", the light sensing element CSA K outputs the light sensing signal S LS1K according to the accumulated energy E R1K ; and the light sensing when the shutter period signal S ST2 represents "on" The component CSB K senses the energy of the reflected light L RD generated by the reflected light L ID reflected by the reflection point PN K of the scene P to accumulate energy E R2K ; when the shutter period signal S ST2 represents "off", the light The sensing element CSB K does not sense the energy of the reflected light L RD generated by the reflected light L ID reflected by the reflection point PN K of the scene P, without accumulating the energy E R2K . When the read signal S RE representing "read" the light sensing element according to CSB K have been accumulated energy E R2K, to output light detection signals S LS2K. In addition, when the read signal S RE stands for "read", after the light sensing elements CSA K and CSB K output the light sensing signals S LS1K and S LS2K , the light sensing elements CSA K and CSB K will The accumulated energy E R1K and E R2K are reset (ie, the light sensing elements CSA K and CSB K will clear the accumulated energy).
如此一來,藉由第2圖所說明之測距裝置於「量測背景階段」之運作方法、第4圖所說明之測距裝置於「調整頻率階段」之運作方法,以及第3圖所說明之測距裝置於「計算距離階段」之運作方法,發光/感測控制電路1010係分別可控制光感測組CS1 ~CSM ,以量測場景P之反射點PN1 ~PNM 與3D影像感測裝置1000之待測距離D1 ~DM 。In this way, the operation method of the distance measuring device described in FIG. 2 in the "measurement background phase", the operation method of the distance measuring device described in FIG. 4 in the "adjustment frequency phase", and the third figure The operation method of the distance measuring device in the "calculation distance phase", the light sensing/sensing control circuit 1010 can respectively control the light sensing groups CS 1 ~ CS M to measure the reflection points PN 1 ~ PN M of the scene P and The distance D 1 ~D M of the 3D image sensing device 1000 to be measured.
除此之外,3D影像感測裝置1000,可利用影像感測控制電路1080來控制光感測模組1030,以感測場景P之反射點PN1 ~PNM ,以得到影像I,進而得到子畫素影像資料GA1 ~GAM 與GB1 ~GBM 。更明確地說,影像感測控制電路1080分別控制光感測元件CSA1 與CSB1 ,以感測場景P之反射點PN1 ,以得到對應的兩個子畫素影像資料GA1 與GB1 ...影像感測控制電路1080分別控制光感測元件CSAX 與CSBX ,以感測場景P之反射點PNX ,以得到對應的兩個子畫素影像資料GAX 與GBX (如第11圖所示,反射點PNX 與3D影像感測裝置1000之距離為DX )...影像感測控制電路1080分別控制光感測元件CSAY 與CSBY ,以感測場景P之反射點PNY ,以得到對應的兩個子畫素影像資料GAY 與GBY (如第11圖所示,反射點PNY 與3D影像感測裝置1000之距離為DY )...影像感測控制電路1080分別控制光感測元件CSAM 與CSBM ,以感測場景P之反射點PNM ,以得到對應的兩個子畫素影像資料GAM 與GBM 。如此,本發明之3D影像感測裝置1000,便可利用子畫素影像資料GA1 ~GAM 與GB1 ~GBM 與距離資料D1 ~DM ,以建構出一3D影像。In addition, the 3D image sensing device 1000 can control the light sensing module 1030 by using the image sensing control circuit 1080 to sense the reflection points PN 1 ~PN M of the scene P to obtain the image I, thereby obtaining Sub-pixel image data G A1 ~ G AM and G B1 ~ G BM . More specifically, the image sensing control circuit 1080 controls the light sensing elements CSA 1 and CSB 1 to sense the reflection point PN 1 of the scene P to obtain corresponding two sub-pixel image data G A1 and G B1 . The image sensing control circuit 1080 controls the light sensing elements CSA X and CSB X respectively to sense the reflection point PN X of the scene P to obtain corresponding two sub-pixel image data G AX and G BX (eg As shown in FIG. 11, the distance between the reflection point PN X and the 3D image sensing device 1000 is D X ). The image sensing control circuit 1080 controls the light sensing elements CSA Y and CSB Y to sense the scene P, respectively. Reflecting the point PN Y to obtain the corresponding two sub-pixel image data G AY and G BY (as shown in FIG. 11 , the distance between the reflection point PN Y and the 3D image sensing device 1000 is D Y )... The sensing control circuit 1080 controls the light sensing elements CSA M and CSB M respectively to sense the reflection point PN M of the scene P to obtain corresponding two sub-pixel image data G AM and G BM . Thus, the 3D image sensing device 1000 of the present invention can construct a 3D image by using the subpixel image data G A1 ~ G AM and G B1 ~ G BM and the distance data D 1 ~ D M .
此外,光感測模組1030之光感測組CS1 ~CSM 係為CMOS或CCD感光元件。也就是說,光感測模組1030與數位相機中用來感測影像之感光模組之結構及工作原理相同。換句話說,當3D影像感測裝置1000應用於數位相機時,數位相機不但可利用3D影像感測裝置1000中之影像感測控制電路1080,以控制光感測模組1030來感測場景以得到影像,且數位相機還可利用3D影像感測裝置1000中之測距裝置1090之各元件配合光感測模組1030,以同時對場景之各反射點測距,而得到各畫素之距離資料。如此一來,數位相機可根據感測場景所得到之影像與場景之各反射點與數位相機之距離,以建構一3D影像。且由於3D影像感測裝置1000中之2D影像感測裝置1100與測距裝置1090可共用光感測模組1030,因此可降低建構3D影像的成本。In addition, the light sensing groups CS 1 to CS M of the light sensing module 1030 are CMOS or CCD photosensitive elements. That is to say, the structure and working principle of the light sensing module 1030 and the photosensitive module for sensing images in the digital camera are the same. In other words, when the 3D image sensing device 1000 is applied to a digital camera, the digital camera can use the image sensing control circuit 1080 in the 3D image sensing device 1000 to control the light sensing module 1030 to sense the scene. The image is obtained, and the digital camera can also use the components of the distance measuring device 1090 in the 3D image sensing device 1000 to cooperate with the light sensing module 1030 to simultaneously measure the reflection points of the scene to obtain the distance of each pixel. data. In this way, the digital camera can construct a 3D image according to the distance between the image obtained by sensing the scene and the reflection point of the scene and the digital camera. Moreover, since the 2D image sensing device 1100 and the distance measuring device 1090 in the 3D image sensing device 1000 can share the light sensing module 1030, the cost of constructing the 3D image can be reduced.
為了使測距裝置可更正確地計算出待測距離,本發明更進一步地提供可提高測距裝置之訊雜比之方法。In order to enable the distance measuring device to more accurately calculate the distance to be measured, the present invention further provides a method for improving the signal to noise ratio of the distance measuring device.
請參考第12圖。第12圖係為說明本發明之可提高測距裝置之訊雜比之方法之第一實施例1200之流程圖。方法1200適用於一測距裝置DMD。測距裝置DMD用來量測待測物MO與測距裝置DMD之間之待測距離DM 。如第13圖所示,測距裝置DMD具有一發光/感測控制電路1310、一距離計算電路1320、一發光元件LD、聚光模組LEN與一光感測元件CSU1 。其中發光元件LD、聚光模組LEN之結構及工作原理分別與發光元件120、520、820、1020及聚光模組170、570、870類似,光感測元件CSU1 可以光感測元件531、532實施。光感測元件CSU1 用來根據一快門週期訊號SST1 ,以感測並累積光之能量,來據以產生光感測訊號SLS1 。方法1200之步驟說明如下:步驟1210:發光/感測控制電路1310透過發光週期訊號SLD 以控制發光元件LD於發光時間TLD 內,持續發出偵測光LID 射向待測物MO,以產生反射光LRD ;步驟1220:當發光元件LD開始發出偵測光LID 後,經過延遲時間TDELAY 後,發光/感測控制電路1310切換快門週期訊號SST1 於感測時間TSEN1 內皆表示「開啟」,以使光感測元件CSU1 感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS1 ;步驟1230:距離計算電路1320根據於發光時間TLD 內發光元件LD所發出之偵測光LID 之能量與光感測訊號SLS1 ,以得到光往返測距裝置DMD與待測物MO之光飛行時間(Time of Flight,TOF)TTOF ;步驟1240:距離計算電路1320根據光飛行時間TTOF ,以得到該待測距離DM ,並據以產生一代表待測距離DM 之輸出訊號SOUT 。Please refer to Figure 12. Figure 12 is a flow chart showing a first embodiment 1200 of the method of the present invention for improving the signal to noise ratio of a distance measuring device. Method 1200 is applicable to a ranging device DMD. The distance measuring device DMD is used to measure the distance D M to be measured between the object to be tested MO and the distance measuring device DMD. As shown in FIG. 13, the distance measuring device DMD has a light/sensing control circuit 1310, a distance calculating circuit 1320, a light emitting element LD, a light collecting module LEN and a light sensing element CSU 1 . The structure and working principle of the light-emitting element LD and the concentrating module LEN are similar to the light-emitting elements 120, 520, 820, and 1020 and the concentrating modules 170, 570, and 870, respectively, and the light sensing element CSU 1 can be the light sensing element 531. 532 implementation. The light sensing component CSU 1 is configured to generate and accumulate light energy according to a shutter period signal S ST1 to generate a light sensing signal S LS1 . The method of the method 1200 is as follows: Step 1210: The illuminating/sensing control circuit 1310 transmits the illuminating element LD to the illuminating time T LD through the illuminating period signal S LD , and continuously emits the detecting light L ID to the object to be tested MO to The reflected light L RD is generated. Step 1220: After the light-emitting element LD starts to emit the detection light L ID , after the delay time T DELAY , the light-emitting/sensing control circuit 1310 switches the shutter period signal S ST1 to the sensing time T SEN1 . Indicates "ON", so that the light sensing element CSU 1 senses and accumulates the energy of the reflected light L RD , and accordingly generates the light sensing signal S LS1 ; Step 1230 : The distance calculating circuit 1320 emits light according to the light emitting time T LD The energy of the detected light L ID and the light sensing signal S LS1 emitted by the component LD are obtained to obtain a Time of Flight (TOF) T TOF of the optical round tripping device DMD and the object to be tested MO; Step 1240: The distance calculation circuit 1320 obtains the to-be-measured distance D M according to the optical flight time T TOF , and accordingly generates an output signal S OUT representing the to-be-measured distance D M .
請參考第14圖。在步驟1210中,發光/感測控制電路1310透過發光週期訊號SLD 以控制發光元件LD於發光時間TLD 內,持續發出偵測光LID 射向待測物MO,且待測物MO反射偵測光LID 以產生反射光LRD 。當發光元件LD開始發出偵測光LID 後,經過一光飛行時間TTOF ,反射光LRD 返回至光感測元件CSU1 。其中光飛行時間TTOF 即為偵測光LID 從發光元件LD射至待測物MO之時間加上反射光LRD 從待測物MO射至光感測元件CSU1 之時間,換句話說,光飛行時間TTOF 即為光往返測距裝置DMD與待測物MO所需之時間。Please refer to Figure 14. In step 1210, the illuminating/sensing control circuit 1310 transmits the illuminating period signal S LD to control the illuminating element LD in the illuminating time T LD , continuously emits the detecting light L ID to the object to be tested MO, and the object to be tested MO reflects The light L ID is detected to generate reflected light L RD . After the light-emitting element LD starts to emit the detection light L ID , the reflected light L RD returns to the light sensing element CSU 1 after a light flight time T TOF . The light flight time T TOF is the time when the detected light L ID is emitted from the light emitting element LD to the object to be tested MO, and the time when the reflected light L RD is emitted from the object to be tested MO to the light sensing element CSU 1 , in other words, in other words The light flight time T TOF is the time required for the optical round tripping device DMD and the object to be tested MO.
在步驟1220中,當發光元件LD開始發出偵測光LID 後,經過延遲時間TDELAY ,此時發光/感測控制電路1310切換快門週期訊號SST1 表示「開啟」並維持一段感測時間TSEN1 。換句話說,光感測元件CSU1 於感測時間TSEN1 內會感測光之能量,並據以產生光感測訊號SLS1 。測距裝置DMD視其應用,通常其可量測之待測距離DM 之範圍皆可定義出一適當範圍。在本發明中,待測距離DM 之範圍介於已知最短量測距離DMIN 與已知最長距離DMAX 之間。舉例而言,測距裝置DMD應用於一遊樂器系統。測距裝置DMD設置於顯示系統附近。遊樂器系統利用測距裝置DMD偵測使用者之待測距離DM ,並依據所量測之待測距離DM ,以控制遊戲與使用者的互動,以網球遊戲為例,當使用者之待測距離DM 縮短時,可將使用者於遊戲中控制的角色往前移動;當使用者之待測距離DM 增加時,可將使用者於遊戲中控制的角色往後移動。由於當使用者與顯示系統(測距裝置DMD)之間之待測距離DM 太近時(如小於已知最短量測距離DMIN ),此時使用者可能無法看到顯示系統所顯示之影像,而無法與遊樂器系統互動,換句話說,使用者之待測距離DM 僅有在大於已知最短量測距離DMIN 時,測距裝置DMD所量測之待測距離DM 才可用來提供給遊樂器系統作為遊戲互動的依據。因此在步驟1220中,發光/感測控制電路1310係根據已知最短待測距離DMIN 以計算延遲時間TDELAY ,其目的在於使反射光LRD 於延遲時間TDELAY 之後才射至光感測元件CSU1 。發光/感測控制電路1310根據下式計算延遲時間TDELAY :In step 1220, after the light-emitting element LD starts to emit the detection light L ID , the delay time T DELAY elapses. At this time, the illumination/sense control circuit 1310 switches the shutter period signal S ST1 to indicate "on" and maintains a sensing time T. SEN1 . In other words, the light sensing element CSU 1 senses the energy of the light during the sensing time T SEN1 and accordingly generates the light sensing signal S LS1 . The distance measuring device DMD can generally define an appropriate range by measuring the range of the distance D M that can be measured. In the present invention, the range of the distance D M to be measured is between the known shortest measurement distance D MIN and the known longest distance D MAX . For example, the ranging device DMD is applied to a game system. The distance measuring device DMD is disposed near the display system. The game system uses the distance measuring device DMD to detect the user's distance D M to be measured, and according to the measured distance D M to control the interaction between the game and the user, taking the tennis game as an example, when the user When the distance D M to be measured is shortened, the character controlled by the user in the game can be moved forward; when the distance D M of the user is increased, the character controlled by the user in the game can be moved backward. Since when the distance D M between the user and the display system (the distance measuring device DMD) is too close (for example, less than the known shortest measuring distance D MIN ), the user may not be able to see the display system displayed at this time. The image cannot be interacted with the game system. In other words, the distance D M of the user to be measured is only greater than the known shortest measurement distance D MIN , and the distance D M measured by the distance measuring device DMD is Can be used to provide the game system as the basis for game interaction. Therefore, in step 1220, the illumination/sensing control circuit 1310 calculates the delay time T DELAY based on the known shortest distance to be measured D MIN , the purpose of which is to cause the reflected light L RD to be incident on the light sensing after the delay time T DELAY . Component CSU 1 . The illumination/sensing control circuit 1310 calculates the delay time T DELAY according to the following formula:
TDELAY =2×DMIN /C...(6);T DELAY = 2 × D MIN / C... (6);
由於待測距離DM 大於已知最短待測距離DMIN ,因此當測距裝置DMD量測待測距離DM 時之光飛行時間TTOF 大於式(6)所計算出之延遲時間TDELAY 。也就是說,雖然光感測元件CSU1 於發光元件LD開始發出偵測光LID 後,經過延遲時間TDELAY ,才開始感測光之能量,但是光感測元件CSU1 仍可及時地感測到從待測物MO所反射的反射光LRD 。Since the distance D M to be measured is greater than the known shortest distance to be measured D MIN , the optical flight time T TOF when the distance measuring device DMD measures the distance D M to be measured is greater than the delay time T DELAY calculated by the equation (6). That is, although the light sensing element CSU 1 starts to sense the energy of the light after the delay time T DELAY is elapsed after the light emitting element LD starts to emit the detection light L ID , the light sensing element CSU 1 can still sense in time. To the reflected light L RD reflected from the object to be tested MO.
在步驟1230中,光感測訊號SLS1 係可反應光感測元件CSU1 所感測到之反射光LRD 之能量。如此,距離計算電路1320根據光感測元件CSU1 所感測到之反射光LRD 之能量與發光元件LD於發光時間TLD 內所發出之偵測光LID 之能量之間之比例,即可得到光往返測距裝置DMD與待測物MO之光飛行時間TTOF 。In step 1230, the light sensing signal S LS1 is responsive to the energy of the reflected light L RD sensed by the light sensing element CSU 1 . Thus, the distance calculation circuit 1320 can calculate the ratio of the energy of the reflected light L RD sensed by the light sensing element CSU 1 to the energy of the detected light L ID emitted by the light emitting element LD during the light emitting time T LD . The light flight time T TOF of the optical round tripping device DMD and the object to be tested MO is obtained.
在步驟1240中,由於光飛行時間TTOF 為光往返待測距離DM 所需之時間,因此距離計算電路1320根據下式可計算出待測距離DM :In step 1240, since the light flight time T TOF is the time required for the light to travel to and from the distance D M to be measured, the distance calculation circuit 1320 can calculate the distance D M to be measured according to the following formula:
DM =TTOF ×C/2...(7);D M =T TOF ×C/2...(7);
其中C表示光速。如此,距離計算電路1320可產生代表待測距離DM 之輸出訊號SOUT 。Where C represents the speed of light. As such, the distance calculation circuit 1320 can generate an output signal S OUT representative of the distance D M to be measured.
相較於先前技術之方法中,測距裝置DMD之光感測元件CSU1 於發光元件LD開始發出偵測光LID 時即開始感測光之能量,在本發明之方法1200之步驟1220中,發光/感測控制電路1310透過快門週期訊號SST1 以控制光感測元件CSU1 於發光元件LD開始發出偵測光LID 後,經過延遲時間TDELAY ,才開始感測光之能量,如此可使光感測元件CSU1 於延遲時間TDELAY 內不感測背景光LB (雜訊)之能量,以提高光感測元件CSU1 所產生之光感測訊號SLS1 之訊雜比。更明確地說,設光感測元件CSU1 於發光元件LD停止發射偵測光LID 時停止感測光之能量(如第14圖所示),在先前技術中,光感測元件CSU1 所感測到之背景光LB 之能量EB_OLD 正比於發光時間TLD ,光感測元件CSU1 所感測到之反射光LRD 之能量為ER_OLD ;在本發明之方法1200中,光感測元件CSU1 所感測到之背景光LB 之能量EB_NEW 正比於感測時間TSEN1 ,且由於反射光LRD 於延遲時間TDELAY 之後才射至光感測元件CSU1 ,因此光感測元件CSU1 所感測到之反射光LRD 之能量仍為ER_OLD 。由此可知,能量EB_NEW 小於能量EB_OLD ,因此相較於先前技術之測距裝置之訊雜比(ER_OLD /EB_OLD ),利用本發明之方法1200所得到之光感測訊號SLS1 ,具有較高的訊雜比(ER_OLD /EB_NEW )。換句話說,利用本發明之方法1200所得到之光感測訊號SLS1 能更正確地反應光感測元件CSU1 所感測到之反射光LRD 之能量,因此在步驟1230中所得到之光飛行時間TTOF 更正確,如此,在步驟1240中即可更正確地計算出待測距離DM 。In the method of the prior art, the light sensing element CSU 1 of the distance measuring device DMD starts to sense the energy of the light when the light emitting element LD starts to emit the detection light L ID . In step 1220 of the method 1200 of the present invention, after the light emitting / sensing circuit 1310 through a shutter control signal S ST1 cycle to control the light sensing element to a light emitting element LD CSU 1 begins to detect light emitted L ID, after a delay time T dELAY, the metering began sensing energy, such that the total The light sensing element CSU 1 does not sense the energy of the background light L B (noise) during the delay time T DELAY to increase the signal-to-noise ratio of the light sensing signal S LS1 generated by the light sensing element CSU 1 . More specifically, the light sensing element CSU 1 stops the energy of the sensing light when the light emitting element LD stops emitting the detection light L ID (as shown in FIG. 14 ). In the prior art, the light sensing element CSU 1 senses The measured energy of the background light L B E B_OLD is proportional to the illumination time T LD , and the energy of the reflected light L RD sensed by the light sensing element CSU 1 is E R — OLD ; in the method 1200 of the present invention, the light sensing element The energy E B_NEW of the background light L B sensed by the CSU 1 is proportional to the sensing time T SEN1 , and since the reflected light L RD is incident on the light sensing element CSU 1 after the delay time T DELAY , the light sensing element CSU a sensed power RD of the reflected light L remains E R_OLD. It can be seen that the energy E B_NEW is smaller than the energy E B_OLD , so the light sensing signal S LS1 obtained by the method 1200 of the present invention is compared with the signal-to-noise ratio (E R_OLD /E B_OLD ) of the distance measuring device of the prior art. Has a high signal-to-noise ratio (E R_OLD /E B_NEW ). In other words, the light sensing signal S LS1 obtained by the method 1200 of the present invention can more accurately reflect the energy of the reflected light L RD sensed by the light sensing element CSU 1 , and thus the light obtained in step 1230 The flight time T TOF is more correct, and thus, in step 1240, the distance to be measured D M can be calculated more correctly.
此外,在第14圖中,反射光LRD 必須於感測時間TSEN1 結束前,射至光感測元件CSU1 ,如此,測距裝置DMD才可量測到待測距離DM 。也就是說,光飛行時間TTOF 必須不大於感測時間TSEN1 之長度與延遲時間TDELAY 之長度之總和。換句話說,測距裝置DMD可量測到之已知最長待測距離DMAX 可以下式表示:In addition, in FIG. 14, the reflected light L RD must be incident on the light sensing element CSU 1 before the end of the sensing time T SEN1 , so that the distance measuring device DMD can measure the distance D M to be measured. That is to say, the light flight time T TOF must not be greater than the sum of the length of the sensing time T SEN1 and the length of the delay time T DELAY . In other words, the known longest distance to be measured D MAX, which can be measured by the ranging device DMD, can be expressed by:
DMAX =2×(TSEN1 +TDELAY )/C...(8)。D MAX = 2 × (T SEN1 + T DELAY ) / C (8).
另外,在第14圖中,感測時間TSEN1 之長度與延遲時間TDELAY 之長度之總和等於發光時間TLD 之長度,也就是說,發光/感測控制電路1310控制光感測元件CSU1 於發光元件LD停止發出偵測光LID 時,即停止感測反射光LRD 之能量。然而,光感測元件CSU1 並不限定必須在發光元件LD停止發出偵測光LID 時,即立刻停止感測反射光LRD 之能量。舉例而言,如第15圖所示,發光/感測控制電路1310可控制感測時間TSEN1 之長度等於發光時間TLD 之長度。此時,根據式(8)可知,由於感測時間TSEN1 增加,因此測距裝置DMD可量測到之最長待測距離DMAX 也隨之增加。In addition, in FIG. 14, the sum of the length of the sensing time T SEN1 and the length of the delay time T DELAY is equal to the length of the lighting time T LD , that is, the lighting/sensing control circuit 1310 controls the light sensing element CSU 1 When the light-emitting element LD stops emitting the detection light L ID , the energy of the reflected light L RD is stopped. However, the light sensing element CSU 1 does not necessarily limit the energy of sensing the reflected light L RD immediately when the light emitting element LD stops emitting the detection light L ID . For example, as shown in FIG. 15, the illumination/sensing control circuit 1310 can control the length of the sensing time T SEN1 to be equal to the length of the lighting time T LD . At this time, according to the formula (8), since the sensing time T SEN1 increases, the longest distance to be measured D MAX that the ranging device DMD can measure also increases.
請參考第16圖。第16圖係為說明本發明之可提高測距裝置之訊雜比之方法之第二實施例1600之流程圖。方法1600適用於一測距裝置DMD。測距裝置DMD用來量測待測物MO與測距裝置DMD之間之待測距離DM 。如第17圖所示,測距裝置DMD具有一發光/感測控制電路1710、一距離計算電路1720、一發光元件LD、聚光模組LEN、光感測元件CSU1 與CSU2 。其中發光元件LD、聚光模組LEN之結構及工作原理與發光元件120、520、820、1020及聚光模組170、570、870類似,光感測元件CSU1 與CSU2 可以光感測元件531、532實施。光感測元件CSU1 用來根據快門週期訊號SST1 ,以感測並累積光之能量,來據以產生光感測訊號SLS1 。光感測元件CSU2 用來根據快門週期訊號SST2 ,以感測並累積光之能量,來據以產生光感測訊號SLS2 ,方法1600之步驟說明如下:步驟1610:發光/感測控制電路1710透過發光週期訊號SLD 控制發光元件LD於發光時間TLD 內,持續發出偵測光LID 射向待測物MO,以產生反射光LRD ;步驟1620:當發光元件LD開始發出偵測光LID 後,經過延遲時間TDELAY 後,發光/感測控制電路1710切換快門週期訊號SLS1 於感測時間TSEN1 內皆表示「開啟」,以使光感測元件CSU1 感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS1 ;步驟1630:當光感測元件CSU1 停止感測反射光LRD 之後,發光/感測控制電路1710切換快門週期訊號SST2 於感測時間TSEN2 內皆表示「開啟」,以使光感測元件CSU2 感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS2 ;步驟1640:距離計算電路1720根據光感測訊號SLS1 與SLS2 之比例,以得到光往返測距裝置DMD與待測物MO之光飛行時間TTOF ;步驟1650:距離計算電路1720根據光飛行時間TTOF ,以得到該待測距離DM ,並據以產生一代表待測距離DM 之輸出訊號SOUT 。Please refer to Figure 16. Figure 16 is a flow chart showing a second embodiment 1600 of the method of the present invention for improving the signal to noise ratio of a distance measuring device. Method 1600 is applicable to a ranging device DMD. The distance measuring device DMD is used to measure the distance D M to be measured between the object to be tested MO and the distance measuring device DMD. As shown in FIG. 17, the distance measuring device DMD has a light-emitting/sensing control circuit 1710, a distance calculating circuit 1720, a light-emitting element LD, a light collecting module LEN, and light sensing elements CSU 1 and CSU 2 . The structure and working principle of the light-emitting element LD and the concentrating module LEN are similar to those of the light-emitting elements 120, 520, 820, and 1020 and the concentrating modules 170, 570, and 870, and the light sensing elements CSU 1 and CSU 2 can be light-sensed. Elements 531, 532 are implemented. The light sensing element CSU 1 is configured to generate and accumulate light energy according to the shutter period signal S ST1 to generate the light sensing signal S LS1 . The light sensing component CSU 2 is configured to generate and accumulate light energy according to the shutter period signal S ST2 to generate the light sensing signal S LS2 . The steps of the method 1600 are as follows: Step 1610: Illumination/Sensing Control the control circuit 1710 through the signal S LD light emission period in the light emitting element LD emission time T LD, continuously detecting light emitted toward the object to be detected L ID MO, to produce a reflected light L RD; step 1620: when the light emitting element LD emits detect start after metering L ID, after a delay time T dELAY, the light emitting / sensing circuit 1710 to switch the shutter control signal S LS1 cycle within the sensing time T SEN1 are represented by "open", so that the light sensing element and a sensing CSU 1 Accumulating the energy of the reflected light L RD and generating the light sensing signal S LS1 accordingly ; Step 1630: After the light sensing element CSU 1 stops sensing the reflected light L RD , the light emitting/sensing control circuit 1710 switches the shutter period signal S ST2 indicates "ON" in the sensing time T SEN2 , so that the light sensing element CSU 2 senses and accumulates the energy of the reflected light L RD , and accordingly generates the light sensing signal S LS2 ; Step 1640: Distance calculation circuit 1720 based on light sensing signals S LS1 and S The ratio of LS2 is used to obtain the optical flight time T TOF of the optical round tripping device DMD and the object to be tested MO; step 1650: the distance calculating circuit 1720 obtains the distance D M according to the optical flight time T TOF , and according to An output signal S OUT representing the distance D M to be measured is generated.
請參考第18圖。在步驟1610中,發光/感測控制電路1710透過發光週期訊號SLD 控制發光元件LD於發光時間TLD 內,持續發出偵測光LID 射向待測物MO,且待測物MO反射偵測光LID 以產生反射光LRD 。當發光元件LD開始發出偵測光LID 後,經過一光飛行時間TTOF ,反射光LRD 返回至光感測元件CSU1 。其中光飛行時間TTOF 即為光往返測距裝置DMD與待測物MO所需之時間。Please refer to Figure 18. In step 1610, the light emitting / sensing control circuit 1710 through a control signal S LD light emission period in the light emitting element LD LD emission time T, continuously detecting light emitted toward the object to be detected L ID MO, MO analyte and detect reflected The light L ID is measured to generate reflected light L RD . After the light-emitting element LD starts to emit the detection light L ID , the reflected light L RD returns to the light sensing element CSU 1 after a light flight time T TOF . The optical flight time T TOF is the time required for the optical round tripping device DMD and the object to be tested MO.
在步驟1620中,當發光元件LD開始發出偵測光LID 後,經過延遲時間TDELAY 後,發光/感測控制電路1710切換快門週期訊號SLS1 於感測時間TSEN1 內皆表示「開啟」,以使光感測元件CSU1 感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS1 。在本實施例中,假設測距裝置DMD可量測之待測距離DM 之範圍介於已知最短量測距離DMIN 與已知最長距離DMAX 之間。因此在步驟1620中,發光/感測控制電路1710可根據式(6)決定延遲時間TDELAY ,以使反射光LRD 於延遲時間TDELAY 之後才射至光感測元件CSU1 ,來確保光感測元件CSU1 可及時地感測到從待測物MO所反射的反射光LRD ,以產生正確的光感測訊號SLS1 。此外,在第18圖中,反射光LRD 仍需於感測時間TSEN1 結束前,射至光感測元件CSU1 ,如此,測距裝置DMD才可量測到待測距離DM 。也就是說,光飛行時間TTOF 必須不大於感測時間TSEN1 之長度與延遲時間TDELAY 之長度之總和。換句話說,測距裝置DMD可量測到之已知最長待測距離DMAX 仍可根據式(8)計算。In step 1620, after the light-emitting element LD starts to emit the detection light L ID , after the delay time T DELAY , the light-emitting/sensing control circuit 1710 switches the shutter period signal S LS1 to indicate "on" in the sensing time T SEN1 . So that the light sensing element CSU 1 senses and accumulates the energy of the reflected light L RD , and accordingly generates the light sensing signal S LS1 . In the present embodiment, it is assumed that the distance D M of the distance to be measured measurable by the distance measuring device DMD is between the known shortest measuring distance D MIN and the known longest distance D MAX . Therefore, in step 1620, the illumination/sensing control circuit 1710 can determine the delay time T DELAY according to equation (6) such that the reflected light L RD is incident on the photo sensing element CSU 1 after the delay time T DELAY to ensure the light. The sensing element CSU 1 can sense the reflected light L RD reflected from the object to be tested MO in time to generate the correct light sensing signal S LS1 . In addition, in FIG. 18, the reflected light L RD still needs to be incident on the light sensing element CSU 1 before the end of the sensing time T SEN1 , so that the distance measuring device DMD can measure the distance D M to be measured. That is to say, the light flight time T TOF must not be greater than the sum of the length of the sensing time T SEN1 and the length of the delay time T DELAY . In other words, the known longest to-be-measured distance D MAX measurable by the ranging device DMD can still be calculated according to equation (8).
在步驟1630中,當光感測元件CSU1 停止感測反射光LRD 之後,發光/感測控制電路1710切換快門週期訊號SST2 於感測時間TSEN2 內皆表示「開啟」。因此,在感測時間TSEN2 內,光感測元件CSU2 根據表示「開啟」之快門週期訊號SST2 ,以感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS2 。In step 1630, after the light sensing element CSU 1 stops sensing the reflected light L RD , the light emitting/sensing control circuit 1710 switches the shutter period signal S ST2 to indicate “on” in the sensing time T SEN2 . Therefore, during the sensing time T SEN2 , the light sensing element CSU 2 senses and accumulates the energy of the reflected light L RD according to the shutter period signal S ST2 indicating “on”, and accordingly generates the light sensing signal S LS2 .
在步驟1640中,光感測訊號SLS1 係可反應光感測元件CSU1 所感測之反射光LRD 之能量;光感測訊號SLS2 係可反應光感測元件CSU2 所感測之反射光LRD 之能量。類似於第3圖所說明之原理,距離計算電路1720根據光感測訊號SLS1 與SLS2 之比例,可得到光往返測距裝置DMD與待測物MO之光飛行時間TTOF 。更明確地說,由第18圖可看出,光飛行時間TTOF 可以下式表示:In step 1640, the light sensing signal S LS1 is responsive to the energy of the reflected light L RD sensed by the light sensing element CSU 1 ; the light sensing signal S LS2 is a reflected light sensed by the reactive light sensing element CSU 2 The energy of L RD . Similar to the principle illustrated in FIG. 3, the distance calculation circuit 1720 can obtain the optical flight time T TOF of the optical round-trip ranging device DMD and the object to be tested MO according to the ratio of the light sensing signals S LS1 and S LS2 . More specifically, as can be seen from Figure 18, the optical time of flight T TOF can be expressed as:
TTOF =TDELAY +TSEN1 -[ER1 /(ER1 +ER2 )]×TLD =TDELAY +TSEN1 -[(SLS1 -EB1 )/(SLS1 -EB1 +SLS2 -EB2 )]×TLD ...(9);T TOF =T DELAY +T SEN1 -[E R1 /(E R1 +E R2 )]×T LD =T DELAY +T SEN1 -[(S LS1 -E B1 )/(S LS1 -E B1 +S LS2 - E B2 )]×T LD ...(9);
當測距裝置DMD具有背景計算電路時,可藉由類似第2圖所說明之方法,以計算出背景光之能量EB1 與EB2 ,或者是當背景光之能量EB1 與EB2 相對於反射光之能量ER1 與ER2 較小時,也可將式(9)直接化簡為:When the distance measuring device DMD has a background calculation circuit, the energy of the background light E B1 and E B2 can be calculated by a method similar to that described in FIG. 2, or when the energy of the background light E B1 and E B2 are relative to When the energy E R1 and E R2 of the reflected light are small, the equation (9) can also be directly reduced to:
TTOF =TDELAY +TSEN1 -[(SLS1 /(SLS1 +SLS2 )]×TLD ...(10)。T TOF = T DELAY + T SEN1 - [(S LS1 /(S LS1 + S LS2 )] × T LD ... (10).
在步驟1650中,由於光飛行時間TTOF 為光往返待測距離DM 所需之時間,因此距離計算電路1720根據式(7)即可計算出待測距離DM ,並據以產生代表待測距離DM 之輸出訊號SOUT 。In step 1650, since the light flight time T TOF is the time required for the light to travel to and from the distance D M to be measured, the distance calculation circuit 1720 can calculate the distance D M to be measured according to the formula (7), and generate a representative The output signal S OUT of the distance D M is measured.
相較於第12圖所說明之方法1200,在本實施例1600中,藉由光感測訊號SLS1 與SLS2 之比例以計算光飛行時間TTOF 。因此,本實施例中,可以第18圖所說明的方式,重覆量測反射光LRD 之能量LR1 與LR2 。當重覆量測N次時,可得到光感測訊號SLS11 ~SLS1N 與SLS21 ~SLS2N 。距離計算電路1720藉由將光感測訊號SLS11 ~SLS1N 累加所得到之光感測訊號SLS1 與將光感測訊號SLS11 ~SLS1N 累加所得到之光感測訊號SLS2 代入式(9)或(10),可計算光飛行時間TTOF ,如此,可減少因反射光LRD 之能量較弱而產生的量測誤差。如此,在步驟1650中,可得到更正確的待測距離DM 。Compared to the method described in FIG. 12 of 1200, 1600 in the present embodiment, the light sensing signal by the ratio of S LS1 and S LS2 of light to calculate the time of flight T TOF. Therefore, in the present embodiment, the energy L R1 and L R2 of the reflected light L RD can be repeatedly measured in the manner described in FIG. When the measurement is repeated N times, the light sensing signals S LS11 ~S LS1N and S LS21 ~S LS2N can be obtained . Distance calculating circuit 1720 by The resulting light sensing signal S LS11 ~ S LS1N accumulated light sensing signal S LS1 and the light sensing signal obtained light sensing signal S LS11 ~ S LS1N accumulated S LS2 into ( 9) or (10), the light flight time T TOF can be calculated, and thus, the measurement error caused by the weak energy of the reflected light L RD can be reduced. Thus, in step 1650, a more correct distance to be measured D M can be obtained.
此外,在方法1600中,可藉由設計感測時間TSEN2 與TSEN1 之長度,以及發光時間TLD 之長度,以控制量測待測距離DM 時,發光元件LD發出偵測光LID 之責任週期(意即發光時間TLD 與偵測週期TC 之比例)。舉例而言,在第19圖中,設計量測週期TC 的長度為2TLD ,感測時間TSEN1 與感測時間TSEN2 之長度相等,且感測時間TSEN1 與感測時間TSEN2 之長度皆等於(TLD -TDELAY /2)。此時,發光元件LD發出偵測光LID 之責任週期為50%。In addition, in the method 1600, the light-emitting element LD emits the detection light L ID by designing the lengths of the sensing times T SEN2 and T SEN1 and the length of the light-emitting time T LD to control the measured distance D M . The duty cycle (meaning the ratio of the illumination time T LD to the detection period T C ). For example, in FIG. 19, the length of the design measurement period T C is 2T LD , the length of the sensing time T SEN1 is equal to the length of the sensing time T SEN2 , and the sensing time T SEN1 and the sensing time T SEN2 are The length is equal to (T LD -T DELAY /2). At this time, the duty cycle of the light-emitting element LD emitting the detection light L ID is 50%.
根據本發明之可提高測距裝置之訊雜比之方法1200與1600之基本精神,本發明更進一步地提供一種適用於第1圖中之測距裝置100之方法,請參考第20圖與第21圖。第20圖與第21圖係為說明本發明之可提高測距裝置之訊雜比之方法之第三實施例2000之示意圖。方法2000之步驟說明如下:步驟2010:發光/感測控制電路110以偵測頻率FC 切換發光週期訊號SLD 表示「開啟」與「關閉」,以使發光元件120切換於一發光時間TLD 內發出偵測光LID 射向待測物MO,來產生反射光LRD ,並於一不發光時間TNLD 內停止發射偵測光LID ;步驟2020:每當發光元件120開始發出偵測光LID 後,經過一延遲時間TDELAY 後,發光/感測控制電路110切換快門週期訊號SST1 於感測時間TSEN1 內皆表示開啟,以使光感測組130感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS1 ;步驟2030:於感測時間TSEN1 後,發光/感測控制電路110切換快門週期訊號SST2 於感測時間TSEN2 內皆表示「開啟」,以使光感測組130感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS2 ;步驟2040:距離計算電路140根據光感測訊號SLS1 與SLS2 之比例,以得到光往返測距裝置100與待測物MO之光飛行時間TTOF ;步驟2050:距離計算電路140根據光飛行時間TTOF ,以得到該待測距離,並據以產生一代表待測距離DM 之輸出訊號SOUT (未圖示於第1圖)。According to the basic spirit of the methods 1200 and 1600 of the present invention for improving the signal-to-noise ratio of the distance measuring device, the present invention further provides a method suitable for the distance measuring device 100 of FIG. 1, please refer to FIG. 20 and 21 picture. 20 and 21 are schematic views showing a third embodiment 2000 of the method of the present invention for improving the signal-to-noise ratio of the distance measuring device. The steps of the method 2000 are as follows: Step 2010: The illumination/sensing control circuit 110 switches the illumination period signal S LD to "on" and "off" at the detection frequency F C to switch the light-emitting element 120 to a light-emitting time T LD . detecting the emitted light toward the object to be detected L ID MO, generating a reflected light L RD, and stops emitting the detection light L ID in a non-emission time T NLD; step 2020: Every time the light emitting element 120 starts to detect emitted After the light L ID , after a delay time T DELAY , the illumination/sensing control circuit 110 switches the shutter period signal S ST1 to indicate that the sensing period T SEN1 is turned on, so that the light sensing group 130 senses and accumulates the reflected light. The energy of the L RD is generated to generate the light sensing signal S LS1 ; Step 2030 : After the sensing time T SEN1 , the lighting/sensing control circuit 110 switches the shutter period signal S ST2 to indicate the sensing time T SEN2 Turning on, so that the light sensing group 130 senses and accumulates the energy of the reflected light L RD , and accordingly generates the light sensing signal S LS2 ; Step 2040 : The distance calculating circuit 140 according to the light sensing signals S LS1 and S LS2 Proportion to obtain optical round-trip distance measuring device 100 and to be tested The light flight time T TOF of the object MO; step 2050: the distance calculation circuit 140 obtains the distance to be measured according to the light flight time T TOF , and accordingly generates an output signal S OUT representing the distance D M to be measured (not shown In Figure 1).
當測距裝置100量測待測物MO之待測距離DM 時,可分為偵測週期TC1 ~TCN ,其中每個偵測週期TC1 ~TCN 之時間長度皆等於(1/FC )。如步驟2010所述,測距裝置100之發光/感測控制電路110以偵測頻率FC 切換發光週期訊號SLD 表示「開啟」與「關閉」,以使發光元件120於每個偵測週期TC1 ~TCN 之發光時間TLD 內發出偵測光LID 射向待測物MO,來產生反射光LRD ,並於每個偵測週期TC1 ~TCN 之不發光時間TNLD 內停止發射偵測光LID 。因此,於每個偵測週期TC1 ~TCN 內,待測物MO反射偵測光LID 以產生反射光LRD 。更明確地說,當發光元件120開始發出偵測光LID 後,經過一光飛行時間TTOF ,待測物MO所產生之反射光LRD 返回至光感測組130,其中光飛行時間TTOF 即為光往返測距裝置100與待測物MO所需之時間。When the distance measuring device 100 measures the to-be-measured distance D M of the object to be tested MO, it can be divided into detection periods T C1 to T CN , wherein each detection period T C1 ~T CN has a time length equal to (1/1/ F C ). As described in step 2010, the illumination/sensing control circuit 110 of the ranging device 100 switches the illumination period signal S LD to "on" and "off" at the detection frequency F C so that the illumination element 120 is in each detection cycle. The detection light L ID emitted from the light-emitting time T LD of T C1 ~T CN is incident on the object to be tested MO to generate the reflected light L RD , and is in the non-light-emitting time T NLD of each detection period T C1 ~T CN Stop transmitting the detection light L ID . Therefore, in each detection period T C1 to T CN , the object to be tested MO reflects the detection light L ID to generate the reflected light L RD . More specifically, after the light-emitting element 120 starts to emit the detection light L ID , after a light flight time T TOF , the reflected light L RD generated by the object to be tested MO returns to the light sensing group 130, wherein the light flight time T The TOF is the time required for the optical reciprocating distance measuring device 100 and the object to be tested MO.
在步驟2020中,在每個偵測週期TC1 ~TCN 中,當發光元件120開始發出偵測光LID 後,經過延遲時間TDELAY 後,發光/感測控制電路110切換快門週期訊號SLS1 於感測時間TSEN1 內皆表示「開啟」,以使光感測組130感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS1 。假設測距裝置100可量測之待測距離DM 之範圍介於已知最短量測距離DMIN 與已知最長距離DMAX 之間,因此在步驟2020中,發光/感測控制電路110可根據式(6)計算延遲時間TDELAY ,以使反射光LRD 於延遲時間TDELAY 之後才射至光感測組130,來確保光感測組130可及時地感測到從待測物MO所反射的反射光LRD ,以產生正確的光感測訊號SLS1 。此外,反射光LRD 仍需於感測時間TSEN1 結束前,射至光感測組130,如此,測距裝置100於感測時間TSEN1 內才可感測到反射光LRD ,以產生正確的光感測訊號SLS1 。因此,測距裝置100可量測到之已知最長待測距離DMAX 仍可以式(8)表示。In step 2020, in each detection period T C1 ~ T CN , after the light-emitting element 120 starts to emit the detection light L ID , after the delay time T DELAY , the illumination/sensing control circuit 110 switches the shutter period signal S. LS1 indicates "on" in the sensing time T SEN1 , so that the light sensing group 130 senses and accumulates the energy of the reflected light L RD , and accordingly generates the light sensing signal S LS1 . It is assumed that the range of the distance D M that the ranging device 100 can measure is between the known shortest measuring distance D MIN and the known longest distance D MAX , so in step 2020 , the lighting/sensing control circuit 110 can The delay time T DELAY is calculated according to equation (6) such that the reflected light L RD is incident on the light sensing group 130 after the delay time T DELAY to ensure that the light sensing group 130 can sense the object to be tested MO in time. The reflected reflected light L RD is generated to produce the correct light sensing signal S LS1 . In addition, the reflected light L RD still needs to be incident on the light sensing group 130 before the end of the sensing time T SEN1 . Thus, the ranging device 100 can sense the reflected light L RD within the sensing time T SEN1 to generate The correct light sensing signal S LS1 . Therefore, the known longest to-be-measured distance D MAX that the ranging device 100 can measure can still be expressed by equation (8).
在步驟2030中,在每個偵測週期TC1 ~TCN 中之感測時間TSEN1 後,發光/感測控制電路110切換快門週期訊號SST2 於感測時間TSEN2 內皆表示「開啟」(如第21圖所示)。因此,光感測組130於感測時間TSEN1 後之感測時間TSEN2 內,根據表示「開啟」之快門週期訊號SST2 ,以感測並累積反射光LRD 之能量,並據以產生光感測訊號SLS2 。此外,由第21圖可看出,快門週期訊號SST1 與發光週期訊號SLD 大致為同相(僅相差延遲時間TDELAY ),且快門週期訊號SST2 與快門週期訊號SST1 大致為反相。In step 2030, after the sensing time T SEN1 in each detection period T C1 ~ T CN , the illumination/sensing control circuit 110 switches the shutter period signal S ST2 to indicate "on" in the sensing time T SEN2 . (as shown in Figure 21). Therefore, the light sensing group 130 senses and accumulates the energy of the reflected light L RD according to the shutter period signal S ST2 indicating "on" during the sensing time T SEN2 after the sensing time T SEN1 , and generates Light sensing signal S LS2 . In addition, as can be seen from FIG. 21, the shutter period signal S ST1 is substantially in phase with the illumination period signal S LD (only the phase difference delay time T DELAY ), and the shutter period signal S ST2 is substantially inverted from the shutter period signal S ST1 .
在步驟2040中,光感測訊號SLS1 係可反應光感測組130所感測之反射光LRD 之能量;光感測訊號SLS2 係可反應光感測組130所感測之反射光LRD 之能量。類似於步驟1640說明之原理,距離計算電路140根據光感測訊號SLS1 與SLS2 之比例,可得到光往返測距裝置100與待測物MO之光飛行時間TTOF 。也就是說,在步驟2040中,距離計算電路140仍可根據式(9)計算出光飛行時間TTOF 。In step 2040, the light sensing signal S LS1 can reflect the energy of the reflected light L RD sensed by the light sensing group 130; the light sensing signal S LS2 is the reflected light L RD sensed by the reactive light sensing group 130. Energy. Similar to the principle explained in step 1640, the distance calculation circuit 140 can obtain the optical flight time T TOF of the optical reciprocating distance measuring device 100 and the object to be tested MO according to the ratio of the optical sensing signals S LS1 and S LS2 . That is, in step 2040, the distance calculation circuit 140 can still calculate the light time of flight T TOF according to equation (9).
此外,由於測距裝置100可藉由第2圖所說明之方法,利用背景計算電路150以得到背景訊號SB (背景訊號SB 係表示單位時間內光感測組130感測背景光LB 所累積之能量),因此第21圖中之背景光之能量EB1 與EB2 可由下式計算:In addition, since the distance measuring device 100 can use the background calculation circuit 150 to obtain the background signal S B by the method illustrated in FIG. 2 (the background signal S B indicates that the light sensing group 130 senses the background light L B per unit time). The accumulated energy), so the energy E B1 and E B2 of the background light in Fig. 21 can be calculated by:
EB1 =SB ×TSEN1 ...(11);E B1 =S B ×T SEN1 ...(11);
EB2 =SB ×TSEN2 ...(12);E B2 = S B × T SEN2 ... (12);
如此一來,根據式(9)、(11)與(12),光飛行時間TTOF 可以下式表示:Thus, according to equation (9), (11), the light time of flight T TOF and can be represented by the formula (12):
TTOF =TDELAY +TSEN1 -[(SLS1 -SB ×TSEN1 )/(SLS1 -SB ×TSEN1 +SLS2 -SB ×TSEN2 )]×TLD ...(13);T TOF =T DELAY +T SEN1 -[(S LS1 -S B ×T SEN1 )/(S LS1 -S B ×T SEN1 +S LS2 -S B ×T SEN2 )]×T LD ...(13) ;
因此,由式(13)可知,距離計算電路140根據背景訊號SB ,可校正光感測訊號SLS1 與SLS2 之間之比例,且距離計算電路140根據校正後之光感測訊號SLS1 與SLS2 之間之比例,可更正確地得到光往返測距裝置100與待測物MO之光飛行時間TTOF 。Therefore, the distance calculation circuit 140 can correct the ratio between the light sensing signals S LS1 and S LS2 according to the background signal S B , and the distance calculation circuit 140 according to the corrected light sensing signal S LS1 The ratio of the distance to the S LS2 can more accurately obtain the optical flight time T TOF of the optical reciprocating distance measuring device 100 and the object to be tested MO.
在步驟2050中,由於光飛行時間TTOF 為光往返待測距離DM 所需之時間,因此距離計算電路根據式(13)與式(7),即可計算出待測距離DM ,並可據以產生代表待測距離DM 之輸出訊號SOUT (未圖示於第1圖)。In step 2050, since the light flight time T TOF is the time required for the light to travel to and from the distance D M to be measured, the distance calculation circuit calculates the distance D M to be measured according to equations (13) and (7), and An output signal S OUT representing the distance D M to be measured can be generated (not shown in Fig. 1).
綜上所述,本發明所提供之方法,可提高測距裝置之訊雜比。本發明之方法包含測距裝置之發光元件於發光時間內,發出偵測光射向待測物以產生反射光、當發光元件開始發出偵測光後,經過一延遲時間,測距裝置之光感測元件感測反射光之能量,並據以產生光感測訊號、根據偵測光之能量與光感測訊號以得到光往返測距裝置與待測物之光飛行時間,以及根據光飛行時間以得到測距裝置與待測物之間之待測距離。由於已知測距裝置所欲量測之待測距離大於一已知最短待測距離,因此本發明之方法可據以計算出適當的延遲時間,以使反射光於延遲時間之後才射至光感測元件。如此,光感測元件於延遲時間內不感測背景光,因此可提高光感測訊號之訊雜比,帶給使用者更大的便利。In summary, the method provided by the present invention can improve the signal-to-noise ratio of the distance measuring device. The method of the present invention comprises the light-emitting element of the distance measuring device emitting the detection light to the object to be tested to generate the reflected light during the illumination time, and after the light-emitting element starts to emit the detection light, after a delay time, the light of the distance measuring device The sensing component senses the energy of the reflected light, and accordingly generates a light sensing signal, according to the energy of the detected light and the light sensing signal to obtain a light flying time of the optical round-trip distance measuring device and the object to be tested, and flying according to the light Time to obtain the distance to be measured between the distance measuring device and the object to be tested. Since it is known that the distance to be measured by the distance measuring device is greater than a known shortest distance to be measured, the method of the present invention can calculate an appropriate delay time so that the reflected light is emitted to the light after the delay time. Sensing element. In this way, the light sensing component does not sense the background light during the delay time, thereby improving the signal-to-noise ratio of the light sensing signal, and providing greater convenience to the user.
以上所述僅為本發明之較佳實施例,凡依本發明申請專利範圍所做之均等變化與修飾,皆應屬本發明之涵蓋範圍。The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.
100、500、800、1090、DMD...測距裝置100, 500, 800, 1090, DMD. . . Distance measuring device
110、511、811、1010、1310、1710...發光/感測控制電路110, 511, 811, 1010, 1310, 1710. . . Illumination/sensing control circuit
120、520、820、1020、LD...發光元件120, 520, 820, 1020, LD. . . Light-emitting element
130、530、830、CS1 ~CSM ...光感測組130, 530, 830, CS 1 ~ CS M. . . Light sensing group
140、540、840、1040、1320、1720...距離計算電路140, 540, 840, 1040, 1320, 1720. . . Distance calculation circuit
150、550、850、1050...背景計算電路150, 550, 850, 1050. . . Background computing circuit
160、560、860、1060...頻率調整電路160, 560, 860, 1060. . . Frequency adjustment circuit
170、570、870、LEN...聚光模組170, 570, 870, LEN. . . Concentrating module
1000...3D影像感測裝置1000. . . 3D image sensing device
1030...光感測模組1030. . . Light sensing module
1100...2D影像感測裝置1100. . . 2D image sensing device
510、810...發光/感測控制模組510, 810. . . Illumination/sensing control module
512、812...驅動電路512, 812. . . Drive circuit
531、532、CSU1 、CSU2 ...光感測元件531, 532, CSU 1 , CSU 2 . . . Light sensing component
1200、1600、2000...方法1200, 1600, 2000. . . method
1210~1240、1610~1650、2010~2050...步驟1210~1240, 1610~1650, 2010~2050. . . step
C1 、C2 ...電容C 1 , C 2 . . . capacitance
D、DM1 ~DM3 ...待測距離D, D M1 ~ D M3 . . . Distance to be measured
DX 、DY ...距離資料D X , D Y . . . Distance data
EB 、ER 、EB1 、EB2 、ER1 、ER2 ...能量E B , E R , E B1 , E B2 , E R1 , E R2 . . . energy
FC ...偵測頻率F C . . . Detection frequency
GAX 、GBX 、GAY 、GBY ...子畫素影像資料G AX , G BX , G AY , G BY . . . Subpixel image data
LB ...背景光L B . . . Background light
LID ...偵測光L ID . . . Detecting light
LRD ...反射光L RD . . . reflected light
O1 、MO...待測物O 1, MO. . . Analyte
P...場景P. . . Scenes
PD1 、PD2 ...感光二極體PD 1 , PD 2 . . . Photosensitive diode
Q1 、Q2 ...電晶體Q 1 , Q 2 . . . Transistor
SB 、SB1 ~SBM ...背景訊號S B , S B1 ~S BM . . . Background signal
SFC ...頻率控制訊號S FC . . . Frequency control signal
SFQ ...頻率訊號S FQ . . . Frequency signal
SLD ...發光週期訊號S LD . . . Luminous period signal
SLS1 、SLS2 、SLS11 ~SLS1M 、SLS21 ~SLS2M ...光感測訊號S LS1 , S LS2 , S LS11 ~S LS1M , S LS21 ~S LS2M . . . Light sensing signal
SP ...階段訊號S P . . . Stage signal
SRE ...讀取訊號S RE . . . Read signal
SST1 、SST2 ...快門週期訊號S ST1 , S ST2 . . . Shutter cycle signal
SSOP1 、SSOP2 、SSOP ...快門開啟脈衝訊號S SOP1 , S SOP2 , S SOP . . . Shutter open pulse signal
SSCP1 、SSCP2 ...快門關閉脈衝訊號S SCP1 , S SCP2 . . . Shutter off pulse signal
SOP1 、SOP2 ...輸出脈衝訊號S OP1 , S OP2 . . . Output pulse signal
SOUT ...輸出訊號S OUT . . . Output signal
SRP1 、SRP2 ...重置脈衝訊號S RP1 , S RP2 . . . Reset pulse signal
SW11 ~SW14 、SW21 ~SW24 ...開關SW 11 ~ SW 14 , SW 21 ~ SW 24 . . . switch
TB ...背景週期T B . . . Background cycle
TC1 ~TCN ...偵測週期T C1 ~T CN . . . Detection cycle
TDELAY ...延遲時間T DELAY . . . delay
TLD ...發光時間T LD . . . Luminous time
TSEN1 、TSEN2 ...感測時間T SEN1 , T SEN2 . . . Sensing time
TTOF ...光飛行時間T TOF . . . Light flight time
VC1 、VC2 ...電壓V C1 , V C2 . . . Voltage
VDD 、VSS ...電壓源V DD , V SS . . . power source
第1圖係為說明根據本發明之第一實施例之測距裝置之示意圖。Fig. 1 is a schematic view showing a distance measuring device according to a first embodiment of the present invention.
第2圖係為說明測距裝置於「量測背景階段」時之內部之控制訊號之波形圖。Figure 2 is a waveform diagram showing the internal control signals of the distance measuring device during the "measurement background phase".
第3圖係為說明測距裝置於「計算距離階段」時之內部之控制訊號之波形圖。Figure 3 is a waveform diagram showing the internal control signals of the distance measuring device during the "calculation distance phase".
第4圖係為說明測距裝置於「調整頻率階段」時之內部之控制訊號之波形圖。Figure 4 is a waveform diagram showing the internal control signals of the distance measuring device in the "adjustment frequency phase".
第5圖係為說明根據本發明之第二實施例之測距裝置之示意圖。Figure 5 is a schematic view showing a distance measuring device according to a second embodiment of the present invention.
第6圖係為說明驅動電路根據第一快門週期訊號、第二快門週期訊號,以及讀取訊號,以產生之各控制訊號之示意圖。Figure 6 is a schematic diagram showing the driving signals generated by the driving circuit according to the first shutter period signal, the second shutter period signal, and the read signal.
第7圖係為說明本發明之光感測組之結構之示意圖。Figure 7 is a schematic view showing the structure of the light sensing group of the present invention.
第8圖係為說明根據本發明之第三實施例之測距裝置之示意圖。Figure 8 is a schematic view showing a distance measuring device according to a third embodiment of the present invention.
第9圖係為說明本發明之光感測元件組之結構之示意圖。Fig. 9 is a schematic view showing the structure of the light sensing element group of the present invention.
第10圖與第11圖係為說明本發明之3D影像感測裝置之示意圖。10 and 11 are schematic views illustrating a 3D image sensing device of the present invention.
第12圖、第13圖、第14圖與第15圖係為說明本發明之可提高測距裝置之訊雜比之方法之第一實施例之示意圖。Fig. 12, Fig. 13, Fig. 14 and Fig. 15 are schematic views for explaining the first embodiment of the method for improving the signal-to-noise ratio of the distance measuring device of the present invention.
第16圖、第17圖、第18圖與第19圖係為說明本發明之可提高測距裝置之訊雜比之方法之第二實施例之示意圖。Fig. 16, Fig. 17, Fig. 18, and Fig. 19 are views showing a second embodiment of the method of the present invention for improving the signal-to-noise ratio of the distance measuring device.
第20圖與第21圖係為說明本發明之可提高測距裝置之訊雜比之方法之第三實施例之示意圖。20 and 21 are views showing a third embodiment of the method of the present invention for improving the signal-to-noise ratio of the distance measuring device.
1200...方法1200. . . method
1210~1240...步驟1210~1240. . . step
Claims (39)
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TW099125136A TWI427273B (en) | 2010-07-29 | 2010-07-29 | Distance-measuring device of increasing a signal-to-noise ratio and method thereof |
US13/046,766 US8638425B2 (en) | 2009-12-03 | 2011-03-13 | Distance-measuring device with increased signal-to-noise ratio and method thereof |
US13/974,011 US9255795B2 (en) | 2009-12-03 | 2013-08-22 | Distance measuring device with increased signal-to-noise ratio and method thereof |
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US8686367B2 (en) * | 2012-03-01 | 2014-04-01 | Omnivision Technologies, Inc. | Circuit configuration and method for time of flight sensor |
US9720076B2 (en) | 2014-08-29 | 2017-08-01 | Omnivision Technologies, Inc. | Calibration circuitry and method for a time of flight imaging system |
JP6860459B2 (en) * | 2017-09-19 | 2021-04-14 | 株式会社東芝 | Distance measuring device |
TWI696842B (en) * | 2018-11-16 | 2020-06-21 | 精準基因生物科技股份有限公司 | Time of flight ranging sensor and time of flight ranging method |
TWI748460B (en) * | 2019-06-21 | 2021-12-01 | 大陸商廣州印芯半導體技術有限公司 | Time of flight device and time of flight method |
US11768277B2 (en) * | 2019-11-05 | 2023-09-26 | Pixart Imaging Incorporation | Time-of-flight sensor and control method thereof |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
TW374114B (en) * | 1997-10-28 | 1999-11-11 | Asia Optical Co Ltd | Method for decreasing the receiver's noise in laser range finder |
US7006142B2 (en) * | 2001-04-16 | 2006-02-28 | Pentax Corporation | Three-dimensional image capturing device |
-
2010
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Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
TW374114B (en) * | 1997-10-28 | 1999-11-11 | Asia Optical Co Ltd | Method for decreasing the receiver's noise in laser range finder |
US7006142B2 (en) * | 2001-04-16 | 2006-02-28 | Pentax Corporation | Three-dimensional image capturing device |
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