TWI730540B - A time-of-flight sensing system and light emitter thereof - Google Patents
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本發明係有關於一種飛時偏光感測系統，特別是關於一種利用偏極光特性的飛時偏光感測系統。 The present invention relates to a time-of-flight polarization sensing system, in particular to a time-of-flight polarization sensing system using the characteristics of polarized light.
飛時測距法(Time-of-Fight,ToF)為近年來經常受到應用的主動式3D掃描技術，主要原因為可測距離範圍大、解析度高且軟體複雜度低，有利於市場的拓展及技術的開發。 Time-of-Fight (ToF) is an active 3D scanning technology that has been frequently used in recent years. The main reasons are the large measurable range, high resolution and low software complexity, which is beneficial to market expansion. And technology development.
飛時測距法的感測技術是在傳統的影像感測器上再增加另一個可量測深度資訊的感測元件，此一元件是以感測光反射接收的時間變化來計算深度資訊。 The sensing technology of the time-of-flight method is to add another sensor element that can measure the depth information on the traditional image sensor. This element calculates the depth information by sensing the time change of light reflection and reception.
就目前而言，習知的飛時測距法的感測技術一般採用850nm及940nm兩種波長之紅外光(Infrared Radiation,IR)作為發射光，其原因在於此波長較不受環境光之干擾，如此一來才能取得較清晰的深度資訊。然而，一般環境中仍然存在此兩種波段的光，因此如何再次降低環境中的自然光的干擾則為研發人員應解決的問題之一。 At present, the sensing technology of the conventional time-of-flight distance measurement method generally uses two wavelengths of 850nm and 940nm infrared light (Infrared Radiation, IR) as the emitted light, the reason is that this wavelength is less interfered by ambient light , In this way can get clearer in-depth information. However, the light of these two wavelength bands still exists in the general environment, so how to reduce the interference of natural light in the environment again is one of the problems that should be solved by the developers.
本發明的目的係提供一種飛時偏光感測系統及其光發射器，該飛時偏光感測系統藉由偏極化的雷射光源執行ToF感測技術之運算，使該偏光感測系統達到提升準確度、降低環境光干擾以及提升訊號雜訊比等功效。 The purpose of the present invention is to provide a time-of-flight polarization sensing system and its light emitter. The time-of-flight polarization sensing system uses a polarized laser light source to perform the calculation of the ToF sensing technology, so that the polarization sensing system can achieve Improve accuracy, reduce ambient light interference, and improve signal-to-noise ratio.
為達上述目的，本發明提供一種飛時偏光感測系統，包括：光發射器，發射第一偏極化方向的第一脈衝光與具有第二偏極化方向的第二脈衝光；光感測器，用於感測反射後的第一脈衝光與第二脈衝光；以及信號處理電路(Signal Processor)，耦接光發射器與光感測器。 To achieve the above objective, the present invention provides a time-of-flight polarization sensing system, including: a light emitter that emits a first pulsed light with a first polarization direction and a second pulsed light with a second polarization direction; The sensor is used to sense the reflected first pulsed light and the second pulsed light; and a signal processing circuit (Signal Processor) is coupled to the light emitter and the light sensor.
根據本發明的光發射器可以由光發射陣列、第一方向偏光片與第二方向偏光片所組成。其中，光發射陣列可以為例如：脈衝光發射器或雷射二極體（Laser Diode），並且第一方向偏光片與第二方向偏光片可以為雙折射晶體 (Briefringence Crystal Materials)或金屬光柵(Metal Grating)。The light emitter according to the present invention may be composed of a light emitting array, a first direction polarizer and a second direction polarizer. The light emitting array can be, for example, a pulsed light emitter or a laser diode, and the first direction polarizer and the second direction polarizer can be birefringent crystals (Briefringence Crystal Materials) or metal gratings. Metal Grating).
較佳地，在本發明的一實施方式中，該光發射陣列可以採用面射型雷射(VCSEL)，以降低指向性達到提升投射包覆範圍之目的。Preferably, in an embodiment of the present invention, the light emitting array may use a surface-emitting laser (VCSEL) to reduce the directivity to achieve the purpose of increasing the projection coverage range.
較佳地，當第一方向偏光片與第二方向偏光片為金屬光柵時，該金屬光柵中金屬線與金屬線之間的週期間距可以小於光發射陣列所放出的光的波長之二分之一。Preferably, when the first direction polarizer and the second direction polarizer are metal gratings, the periodic interval between the metal lines and the metal lines in the metal grating can be less than half the wavelength of the light emitted by the light emitting array one.
根據本發明的光發射器可以進一步包含光擴散器，其將任何平行輸入的入射光轉化成均勻強度以及理想的光斑形狀輸出，並且光擴散器可以設置在光發射陣列上方。The light emitter according to the present invention may further include a light diffuser, which converts any parallel input incident light into uniform intensity and ideal spot shape output, and the light diffuser may be arranged above the light emitting array.
較佳地，在本發明的一實施方式中，該第一方向偏光片與該第二方向偏光片設置在該光擴散器上，且該光擴散器設置在該光發射陣列上。Preferably, in an embodiment of the present invention, the first direction polarizer and the second direction polarizer are arranged on the light diffuser, and the light diffuser is arranged on the light emitting array.
較佳地，在本發明的一實施方式中，該第一方向偏光片與該第二方向偏光片設置在該光擴散器中，且該光擴散器設置在該光發射陣列上。Preferably, in an embodiment of the present invention, the first direction polarizer and the second direction polarizer are arranged in the light diffuser, and the light diffuser is arranged on the light emitting array.
根據本發明的光感測器，用於感測反射的脈衝光，以藉由第一子像素重複單元輸出第一感測信號以及藉由第二子像素重複單元輸出第二感測信號至信號處理電路。其中，第一子像素重複單元包括複數個彩色子像素單元以及具有第一偏極化方向的第一脈衝光感測單元；第二子像素重複單元包括複數個彩色子像素單元以及具有第二偏極化方向的第二脈衝光感測單元。The light sensor according to the present invention is used to sense reflected pulsed light to output a first sensing signal through the first sub-pixel repeating unit and output a second sensing signal to the signal through the second sub-pixel repeating unit Processing circuit. Wherein, the first sub-pixel repeating unit includes a plurality of color sub-pixel units and a first pulsed light sensing unit with a first polarization direction; the second sub-pixel repeating unit includes a plurality of color sub-pixel units and has a second polarization direction. The second pulsed light sensing unit in the polarization direction.
根據本發明的信號處理電路，其依據第一感測信號以及第二感測信號來決定脈衝信號。信號處理電路依據脈衝光以及脈衝信號以計算感測目標的深度資訊，並且該信號處理電路可以為數位電路或類比電路。According to the signal processing circuit of the present invention, the pulse signal is determined according to the first sensing signal and the second sensing signal. The signal processing circuit calculates the depth information of the sensing target according to the pulsed light and the pulse signal, and the signal processing circuit can be a digital circuit or an analog circuit.
本發明之另一目的是提供一種飛時偏光感測的方法，包括下列步驟：一發射步驟，藉由光發射器，發射具有第一偏極化方向的第一脈衝光與具有第二偏極化方向的第二脈衝光；一感測步驟，藉由光感測器感測感測目標反射的脈衝光，以藉由第一子像素重複單元輸出第一感測信號以及藉由第二子像素重複單元輸出第二感測信號；一校正步驟，信號處理電路依據第一感測信號以及第二感測信號決定脈衝信號，並消除背景雜訊的信號；一運算步驟，依據脈衝光以及脈衝信號來決定感測目標的深度資訊。Another object of the present invention is to provide a method of time-of-flight polarization sensing, including the following steps: an emission step, using a light emitter to emit a first pulsed light with a first polarization direction and a second polarization The second pulsed light in the direction of chemical conversion; a sensing step, the pulsed light reflected by the sensing target is sensed by the light sensor, and the first sensing signal is output by the first sub-pixel repeating unit and by the second sub-pixel repeating unit. The pixel repeating unit outputs the second sensing signal; a calibration step, the signal processing circuit determines the pulse signal according to the first sensing signal and the second sensing signal, and eliminates the signal of the background noise; a calculation step, based on the pulsed light and the pulse Signal to determine the depth information of the sensing target.
本發明所提供之飛時偏光感測系統及其方法，主要利用本發明之飛時偏光感測系統，並搭配飛時偏光感測的方法，讓使用者可以藉由高訊號雜訊比之偏極化的雷射光源，有效消除環境中自然光所造成的背景雜訊影響並執行ToF感測技術之運算，達到準確、快速、實用以及節省人力成本等目的。The time-of-flight polarization sensing system and method provided by the present invention mainly use the time-of-flight polarization sensing system of the present invention, combined with the time-of-flight polarization sensing method, so that the user can use the high signal-to-noise ratio to deviate The polarized laser light source effectively eliminates the influence of background noise caused by natural light in the environment and executes the calculation of ToF sensing technology to achieve accuracy, speed, practicality and save labor costs.
爲使熟悉該項技藝人士瞭解本發明之目的、特徵及功效，茲藉由下述具體實施例，並配合所附之圖式，對本發明詳加說明如下。In order to enable those skilled in the art to understand the purpose, features, and effects of the present invention, the following specific embodiments and accompanying drawings are used to explain the present invention in detail as follows.
在下文中，將參考附圖詳細地描述本發明的實施例。整份說明書中，相同的附圖標記基本上表示相同的元件。在下文的描述中，當確定相關的習知技術或配置的詳細描述將導致本發明所公開的技術內容混淆時，將省略其詳細描述。在描述幾個實施例時，本說明書中的介紹部分代表性地描述了相同的元件，並且在其他實施例中可以省略。Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Throughout the specification, the same reference numerals basically denote the same elements. In the following description, when it is determined that a detailed description of a related conventional technology or configuration will cause confusion in the technical content disclosed in the present invention, the detailed description thereof will be omitted. When describing several embodiments, the introduction part in this specification typically describes the same elements, and may be omitted in other embodiments.
包含序數的術語，例如第一和第二，可以用於描述各種元件，但是該些元件不受術語的限制。這些術語僅用於區分一個元件與另一個元件。Terms including ordinal numbers, such as first and second, can be used to describe various elements, but these elements are not limited by the terms. These terms are only used to distinguish one element from another.
圖1為本發明之飛時偏光感測系統的示意圖。圖1中所示之飛時測距感測器100包括：信號處理電路110、光發射器120以及光感測器130。其中，信號處理電路110耦接光發射器120以及光感測器130，其可以為數位電路或類比電路；光發射器120可以為例如：脈衝光發射器或雷射二極體，其用以發射出紅外光的光脈衝；光感測器130可以為例如互補式金屬氧化物半導體影像感測器(CMOS Image Sensor,CIS)。
FIG. 1 is a schematic diagram of the time-of-flight polarization sensing system of the present invention. The time-of-flight
圖2為說明本發明之飛時偏光感測系統進行飛時偏光感測方法的步驟的流程圖。首先，於發射步驟S210，藉由光發射器120發射具有偏極化方向的脈衝光，並進到步驟S220。
FIG. 2 is a flowchart illustrating the steps of the time-of-flight polarization sensing method performed by the time-of-flight polarization sensing system of the present invention. First, in the emission step S210, the
於感測步驟S220時，藉由光感測器130感測反射後的脈衝光，以藉由第一子像素重複單元輸出第一感測信號以及藉由第二子像素重複單元輸出第二感測信號，並進到步驟S230。
In the sensing step S220, the reflected pulsed light is sensed by the
於校正步驟S230時，信號處理電路110依據第一感測信號以及第二感測信號決定脈衝信號，並消除背景雜訊之信號，並進到步驟S240。
In the calibration step S230, the
於計算步驟S240時，信號處理電路110依據脈衝光以及脈衝信號來決定感測目標的深度資訊。
In the calculation step S240, the
為供進一步瞭解本發明構造特徵、運用手段及所預期達成之功效，以下將針對本發明之較佳的實施例使用方式加以敘述，相信當可由此而對本發明有更深入且具體瞭解。 In order to further understand the structural features, application methods, and expected effects of the present invention, the preferred embodiments of the present invention will be described below, and it is believed that a deeper and more detailed understanding of the present invention can be obtained from this.
圖3為本發明一實施例之飛時偏光感測系統的示意圖。飛時測距感測器100包括：信號處理電路110、光發射器120、光感測器130以及感測目標200。其中，信號處理電路110耦接光發射器120以及光感測器130，其可以為數位電路或類比電路；光發射器120可以為例如：脈衝光發射器或雷射二極體，其用以發射紅外光的光脈衝；並且光感測器130可以為例如互補式金屬氧化物半導體影像感測器。
FIG. 3 is a schematic diagram of a time-of-flight polarization sensing system according to an embodiment of the present invention. The time-of-flight
在本發明一實施方式中，如圖4A所示，光發射器121可以由光發射陣列410、第一方向偏光片420與第二方向偏光片430所組成。其中，光發射陣列410可以為例如脈衝光發射器或雷射二極體，並且第一方向偏光片420與第二方向偏光片430可以為雙折射晶體或金屬光柵，但不限於此。
In an embodiment of the present invention, as shown in FIG. 4A, the
其中，當第一方向偏光片420與第二方向偏光片430為金屬光柵時，有效偏極化的條件為該金屬光柵中金屬線與金屬線之間的週期間距小於光發射陣列410所放出的光的波長的二分之一，例如：當金屬光柵中金屬線與金屬線之間的週期間距為500nm時，僅能偏極化800nm以上的波長之紅外光區域。然而，當金屬光柵中金屬線與金屬線之間的週期間距為200nm時，可偏極化的範圍從380nm之可見光區域以上至紅外光區域。
Wherein, when the
具體地，如圖4A所示，光發射陣列410可以採用面射型雷射(VCSEL)，以降低指向性達到提升投射包覆範圍之目的。
Specifically, as shown in FIG. 4A, the
具體地，光發射陣列410發射脈衝光經過第一方向偏光片420後，形成具有該第一偏極化方向的第一脈衝光，並且光發射陣列410發射脈衝光經過第二方向偏光片430後，形成具有該第二偏極化方向的第二脈衝光。
Specifically, after the
需要進一步說明的是，根據本發明一實施例的光發射器121，如圖4A所示，由於光發射陣列410採用面射型雷射，其中的每一個單獨的發光源的直徑約為0.015mm，如果使用金屬光柵作為第一方向偏光片420與第二方向偏光片430，將使得製程上難以實施。因此，根據本發明一實施例的光發射器121，其中，第一方向偏光片420與第二方向偏光片430為雙折射晶體。
It should be further explained that, according to the
雖然圖4A顯示了光發射器120的一種實施方式，但本發明不限於此，光發射器120可以進一步包含光擴散器440，光擴散器440設置於光發射器120的上方，如圖4B所示。然而，如圖4B所示的光發射器122的實施例中，當光透過第一方向偏光片420與第二方向偏光片430偏極化後所產生的雜訊，將透過光擴散器440同步放大，造成具有偏極化方向的脈衝光之雜訊比下降。
Although FIG. 4A shows an embodiment of the
因此，如圖4C所示，根據本發明另一實施例之光發射器123，可以將光擴散器440設置於第一方向偏光片420與第二方向偏光片430下方，且該光擴散器440設置在光發射陣列410上方。如此一來，可以有效降低當光透過第一方向偏光片420與第二方向偏光片430偏極化後所產生的雜訊，進而提高偏極化方向的脈衝光之雜訊比，以便得到較佳的解析度以及測深精度，然而本發明不限於此。
Therefore, as shown in FIG. 4C, according to the
進一步地，如圖4D所示，根據本發明另一實施例之光發射器124，第一方向偏光片420'、第二方向偏光片430'相互結合於光擴散器440'，且將
該光擴散器440'設置在光發射陣列410上。其原因在於當光發射陣列410採用面射型雷射，其中的每一個單獨的發光源的直徑約為0.015mm，在製程上難以實現將第一方向偏光片420'、第二方向偏光片430'、和光擴散器440'分別設置。如此一來，根據本發明另一實施例之光發射器124在保有較佳的解析度以及測深精度的同時，有效降低製程時間以及人力成本。需要進一步說明的是，當使用光擴散器440’的情況下，第一方向偏光片420’與第二方向偏光片430’將不再受限於使用雙折射晶體，而是可以使用金屬光柵作為第一方向偏光片420’與第二方向偏光片430’，進一步地有效降低製作成本以及提高製程良率。
Further, as shown in FIG. 4D, according to the
具體地，如圖5A以及圖5B所示，光感測器130可以包含：第一子像素重複單元531以及第二子像素重複單元532。第一子像素重複單元531包含複數個彩色子像素單元以及具有第一偏極化方向的第一脈衝光感測單元IR1；第二子像素重複單元532包含複數個彩色子像素單元以及具有第二偏極化方向的第二脈衝光感測單元IR2，因此根據本發明一實施方式的光感測器130，可以用於取得彩色影像資訊、紅外光影像資訊以及深度資訊。
Specifically, as shown in FIG. 5A and FIG. 5B, the
具體地，在本發明的一實施方式中，光發射器120可以發射具有垂直偏極化方向的脈衝光或水平偏極化方向的脈衝光至感測目標200。
Specifically, in an embodiment of the present invention, the
其中，第一脈衝光感測單元IR1可以具有第一偏極化方向，並且該第一偏極化方向可以為垂直偏極化，第二脈衝光感測單元IR2可以具有第二偏極化方向，並且該第二偏極化方向可以為水平偏極化。舉例而言，光發射器120可以發射具有垂直偏極化方向的脈衝光至感測目標200，並且感測目標200反射具有垂直偏極化方向的脈衝光至位於光感測器130當中，具有垂直偏極化方向的第一脈衝光感測單元IR1與具有水平偏極化方向的第二脈衝光感測單元IR2。
Wherein, the first pulsed light sensing unit IR1 may have a first polarization direction, and the first polarization direction may be vertical polarization, and the second pulsed light sensing unit IR2 may have a second polarization direction And the second polarization direction may be horizontal polarization. For example, the
具體地，參照圖3，信號處理電路110可以依據脈衝光從被發射到感測到反射的脈衝光的時間，根據以下公式(1)來換算脈衝光的光路徑長度，並且根據本發明的飛時測距感測器100可以根據不同偏極化的感測結果，藉此區分經由感測目標200反射的偏極化的脈衝光以及對應於環境光的背景雜訊，並且同時可以適用於各種信號強度和波長的脈衝光。
Specifically, referring to FIG. 3, the
其中，c為光速、d為飛時測距感測器100與感測目標200之間的距離、θ為飛時測距感測器100與感測目標200之間的角度、T為時間。然而當飛時測距感測器100與感測目標200之間的距離d較大時，其中θ可以忽略不計導致cos(θ)的值為1，從而導致光路徑長度的二分之一為飛時測距感測器100與感測目標200之間的距離。
Where c is the speed of light, d is the distance between the time-of-
參照圖3至圖5B，其中，光感測器130的第一脈衝光感測單元IR1接收感測目標200反射後具有垂直偏極化方向的脈衝光後，其可以根據垂直偏極化方向的脈衝光以及所對應的環境光輸出第一感測信號。該第一感測信號包含對應於脈衝光的脈衝信號以及對應於環境光的整體背景雜訊中具有垂直偏極化方向的部分的第一背景雜訊信號，光感測器130的第二脈衝光感測單元IR2接收感測目標200反射後具有垂直偏極化方向的脈衝光後，其可以根據所對應的環境光輸出第二感測信號，並且該第二感測信號包含對應於環境光的整體背景雜訊中剩餘的另一部分具有水平偏極化方向的第二背景雜訊信號。
Referring to FIGS. 3 to 5B, after the first pulsed light sensing unit IR1 of the
必須進一步說明的是，由於第二脈衝光感測單元IR2與脈衝光的偏極化方向不同，因此第二感測信號不包含對應於脈衝光的脈衝信號。 It must be further explained that since the polarization direction of the second pulsed light sensing unit IR2 is different from that of the pulsed light, the second sensing signal does not include the pulsed signal corresponding to the pulsed light.
具體地，由於第一背景雜訊信號的信號強度與第二背景雜訊信號的信號強度相同或相近，因此根據本發明的一實施方式的信號處理電路110可以根據不同偏極化的不同像素單元所取得的第一感測信號以及第二感測信號進行信號強度相減之運算操作，即可取得無背景雜訊的脈衝信號的信號波形。也就是說，本實施例的信號處理電路110可以根據光發射器120發射偏極化的脈衝光與光感測器130感測到脈衝信號之間的時間差，來準確地計算出飛時測距感測器100與感測目標200之間的距離。
Specifically, since the signal strength of the first background noise signal is the same as or similar to the signal strength of the second background noise signal, the
參考圖6並搭配圖2以及圖3，用以顯示說明圖3中之飛時偏光感測系統以進行其方法的流程步驟，可進行以下步驟。 Referring to FIG. 6 in conjunction with FIG. 2 and FIG. 3, it is used to illustrate the flow steps of the time-of-flight polarization sensing system in FIG. 3 to perform its method. The following steps can be performed.
首先，於發射步驟S210，藉由信號處理電路110經使用者控制發出電壓信號Sa，光發射器120依據該電壓信號Sa發射具有垂直偏極化方向的脈衝光，其中，該電壓信號Sa包含脈衝信號P。
First, in the emission step S210, the
接著，進入感測步驟S220，如圖6所示，在信號處理電路110經使用者控制發出電壓信號Sa的同時，具有垂直偏極化方向的第一脈衝光感測單元IR1以及具有水平偏極化方向的第二脈衝光感測單元IR2啟動並持續進行感測，
並且在光發射器120發射具有垂直偏極化方向的脈衝光至感測目標200後，感測目標200反射具有垂直偏極化方向的脈衝光至位於光感測器130當中的第一脈衝光感測單元IR1以及第二脈衝光感測單元IR2時，第一脈衝光感測單元IR1輸出電壓信號Sp以及第二脈衝光感測單元IR2輸出電壓信號Sb。
Next, proceed to the sensing step S220. As shown in FIG. 6, while the
進而，進入校正步驟S230，如圖6所示，由於第一脈衝光感測單元IR1與脈衝光的偏極化方向相同，因此第一脈衝光感測單元IR1輸出的電壓信號Sp可以包含對應於環境光的背景雜訊信號BN’以及脈衝信號P’。在本實施例中，由於第二脈衝光感測單元IR2與脈衝光的偏極化方向不同，因此第二脈衝光感測單元IR2輸出的電壓信號Sp僅包含對應於環境光的背景雜訊信號BN。在本實施例中，處於相同環境光下之背景雜訊信號BN和BN’具有相同或相近的信號強度，因此，信號處理電路110可以藉由比較電壓信號Sp和Sb並進行相減運算得到輸出電壓信號Sr，電壓信號Sr僅具有脈衝信號P’並消除背景雜訊信號。
Furthermore, proceed to the calibration step S230. As shown in FIG. 6, since the polarization direction of the first pulsed light sensing unit IR1 is the same as that of the pulsed light, the voltage signal Sp output by the first pulsed light sensing unit IR1 may contain a voltage signal corresponding to The ambient light background noise signal BN' and pulse signal P'. In this embodiment, since the polarization direction of the second pulsed light sensing unit IR2 is different from that of the pulsed light, the voltage signal Sp output by the second pulsed light sensing unit IR2 only contains the background noise signal corresponding to the ambient light BN. In this embodiment, the background noise signals BN and BN' under the same ambient light have the same or similar signal strength. Therefore, the
最後，進入計算步驟S240，信號處理電路110可以根據電壓信號Sr的脈衝信號P’的發生時間和根據光發射器120發射脈衝光的發生時間，兩者之間的時間差來計算飛時測距感測器100與感測目標200之間的距離。
Finally, entering the calculation step S240, the
需要進一步說明的是，根據本發明的實施方式，僅需藉由簡單的相減運算而不需透過複雜的軟體運算即可消除環境中自然光所造成的背景雜訊信號，有效降低信號處理電路110的處理時間降低軟體複雜度，並且即使在背景雜訊信號BN和BN’的信號強度大於脈衝信號P和P’的情況下，信號處理電路110仍然可以藉由比較電壓信號Sp和Sb並進行相減運算消除背景雜訊信號，有效地執行運算並進行距離感測以獲得準確的距離感測結果。
It should be further explained that, according to the embodiment of the present invention, the background noise signal caused by natural light in the environment can be eliminated by simple subtraction operation without complicated software operation, and the
圖7為依照本發明的一實施例的脈衝信號的信號時序圖。參考圖3以及圖6，當信號處理電路110進行相減運算後取得對應於光感測器130感測到的脈衝光的無背景雜訊的脈衝信號，信號處理電路110可以藉由執行直接飛時(Direct Time-of-Flight,D-ToF)測距運算來計算脈衝光的傳遞時間，以計算感測目標200之深度資訊，其中，感測目標200的深度資訊係指飛時測距感測器100與感測目標200之間的距離。具體地，信號處理電路110依據光發射器120發射脈衝光(脈衝信號P1)與光感測器130感測到反射的脈衝光(脈衝信號P1’)之間的時間差T1來計算感測目標200的深度資訊。時間差T1可以為例如脈衝信號P1的上升緣至脈衝信號P1’的上升緣之間的時間長度，也就是說，在本實施例中，信號處理電路110可以將時間差T1乘以光速(c)再除以2以取得距離資訊。FIG. 7 is a signal timing diagram of a pulse signal according to an embodiment of the invention. 3 and 6, when the
需要進一步說明的是，根據本發明的實施方式，使用飛時測距法的感測技術將不再受限於僅能使用850nm及940nm兩種波長之紅外光做為發射光，而是可以使用各種波長甚至是可見光的波長範圍做為發射光，有效提升本發明之適用範圍以及實用性。It should be further explained that, according to the embodiment of the present invention, the sensing technology using the time-of-flight ranging method will no longer be limited to using only two wavelengths of 850nm and 940nm infrared light as emitted light, but can be used Various wavelengths and even the wavelength range of visible light are used as emitted light, which effectively enhances the scope of application and practicability of the present invention.
藉此，本發明具有以下之實施功效及技術功效：Therefore, the present invention has the following implementation effects and technical effects:
其一，本發明藉由將光擴散器440，設置於第一方向偏光片420與第二方向偏光片430和光發射陣列410之間，有效降低當光透過第一方向偏光片420與第二方向偏光片430偏極化後所產生的雜訊，進而提高偏極化方向的脈衝光之雜訊比，以得到較佳的解析度以及測深精度。First, in the present invention, by arranging the
其二，本發明進一步透過將第一方向偏光片420與第二方向偏光片430設置在光擴散器440’中，且將該光擴散器440’設置於光發射陣列410上。如此一來，在保有較佳的解析度以及測深精度的同時，有效降低製作時間以及人力成本。Second, the present invention further transmits the
其三，利用本發明之飛時偏光感測系統，並搭配飛時偏光感測的方法，讓使用者可以藉由高訊號雜訊比之偏極化的雷射光源，有效消除環境中自然光所造成的背景雜訊影響並執行ToF感測技術之運算，進一步提升測距的精準度以及實用性。Third, using the in-flight polarization sensing system of the present invention, combined with the in-flight polarization sensing method, allows the user to use a polarized laser light source with a high signal-to-noise ratio to effectively eliminate the natural light in the environment. The resulting background noise is affected and the ToF sensing technology is executed to further improve the accuracy and practicability of ranging.
以上係藉由特定的具體實施例說明本發明之實施方式，所屬技術領域具有通常知識者可由本說明書所揭示之內容輕易地瞭解本發明之其他優點及功效。The above is a description of the implementation of the present invention through specific specific examples. Those with ordinary knowledge in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification.
以上所述僅為本發明之較佳實施例，並非用以限定本發明之範圍；凡其它未脫離本發明所揭示之精神下所完成之等效改變或修飾，均應包含在下述之專利範圍內。The above are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention; all other equivalent changes or modifications made without departing from the spirit of the present invention should be included in the following patent scope Inside.
100:飛時測距感測器 110:信號處理電路 120:光發射器 121:光發射器 122:光發射器 123:光發射器 124:光發射器 130:光感測器 200:感測目標 410:光發射陣列 420:第一方向偏光片 430:第二方向偏光片 440:光擴散器 440’:光擴散器 531:第一子像素重複單元 532:第二子像素重複單元 B:背景雜訊信號 B':背景雜訊信號 IR1:第一脈衝光感測單元 IR2:第二脈衝光感測單元 P:脈衝信號 P':脈衝信號 P1:脈衝信號 P1’: 脈衝信號 Sa:電壓信號 Sb:電壓信號 Sp:電壓信號 T1:時間差 S210:發射步驟 S220:感測步驟 S230:校正步驟 S240:計算步驟 100: Time-of-flight ranging sensor 110: signal processing circuit 120: light transmitter 121: Light Transmitter 122: Light Transmitter 123: Light Transmitter 124: Light Transmitter 130: light sensor 200: sense target 410: light emitting array 420: first direction polarizer 430: second direction polarizer 440: light diffuser 440’: Light diffuser 531: the first sub-pixel repeating unit 532: second sub-pixel repeating unit B: Background noise signal B': background noise signal IR1: The first pulse light sensing unit IR2: second pulse light sensing unit P: Pulse signal P': Pulse signal P1: Pulse signal P1’: Pulse signal Sa: voltage signal Sb: voltage signal Sp: voltage signal T1: Time difference S210: Launch procedure S220: Sensing step S230: Calibration steps S240: Calculation steps
圖1為本發明之飛時偏光感測系統的示意圖； 圖2為說明本發明之飛時偏光感測系統進行飛時偏光感測方法的步驟的流程圖； 圖3為本發明的一實施例之飛時偏光感測系統的示意圖； 圖4A為本發明的一實施例之光發射器的示意圖； 圖4B為本發明的另一實施例之光發射器的示意圖； 圖4C為本發明的另一實施例之光發射器的示意圖； 圖4D為本發明的另一實施例之光發射器的示意圖； 圖5A為依照本發明的一實施例的第一子像素重複單元的示意圖； 圖5B為依照本發明的一實施例的第二子像素重複單元的示意圖； 圖6為依照本發明的一實施例的多個信號波形的時序圖； 圖7為依照本發明的一實施例的脈衝信號的時序圖； Figure 1 is a schematic diagram of the time-of-flight polarization sensing system of the present invention; 2 is a flow chart illustrating the steps of the time-of-flight polarization sensing method performed by the time-of-flight polarization sensing system of the present invention; 3 is a schematic diagram of a time-of-flight polarization sensing system according to an embodiment of the present invention; 4A is a schematic diagram of a light emitter according to an embodiment of the invention; 4B is a schematic diagram of a light emitter according to another embodiment of the invention; 4C is a schematic diagram of a light transmitter according to another embodiment of the present invention; 4D is a schematic diagram of a light emitter according to another embodiment of the invention; 5A is a schematic diagram of a first sub-pixel repeating unit according to an embodiment of the invention; 5B is a schematic diagram of a second sub-pixel repeating unit according to an embodiment of the invention; 6 is a timing diagram of multiple signal waveforms according to an embodiment of the present invention; FIG. 7 is a timing diagram of a pulse signal according to an embodiment of the present invention;
100:飛時測距感測器 100: Time-of-flight ranging sensor
110:信號處理電路 110: signal processing circuit
120:光發射器 120: light transmitter
130:光感測器 130: light sensor
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