CN112668425A - Fingerprint detection method, fingerprint sensor and electronic equipment - Google Patents
Fingerprint detection method, fingerprint sensor and electronic equipment Download PDFInfo
- Publication number
- CN112668425A CN112668425A CN202011511799.2A CN202011511799A CN112668425A CN 112668425 A CN112668425 A CN 112668425A CN 202011511799 A CN202011511799 A CN 202011511799A CN 112668425 A CN112668425 A CN 112668425A
- Authority
- CN
- China
- Prior art keywords
- display screen
- pixel array
- period
- fingerprint sensor
- pixels
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Image Input (AREA)
- Measurement Of The Respiration, Hearing Ability, Form, And Blood Characteristics Of Living Organisms (AREA)
Abstract
The application provides a fingerprint detection method, a fingerprint sensor and electronic equipment, which are easier to reduce the influence of the brightness change of a display screen on fingerprint detection and improve the performance of fingerprint detection. The fingerprint detection method comprises the following steps: receiving a synchronous signal of a display screen, wherein the synchronous signal is used for triggering a pixel array of a fingerprint sensor to perform exposure, the period of the synchronous signal is synchronous with a dimming period of the display screen, and the dimming period comprises a bright period and a dark period; and based on the triggering of the synchronous signal, sequentially exposing pixels of each row of the pixel array so as to ensure that the exposure time in the pixel array is constant with the position of the pixel corresponding to the dark time period, wherein the data of the exposed pixels of each row are used for acquiring a fingerprint image.
Description
Technical Field
The embodiment of the application relates to the field of information technology, and more particularly relates to a fingerprint detection method, a fingerprint sensor and an electronic device.
Background
The current electronic equipment pursues higher screen occupation ratio, and more front devices need to be moved below the screen, such as a proximity sensor, an ambient light sensor and the like. When the ambient light sensor is disposed below the display screen of the electronic device, the ambient light sensor needs to detect the light intensity of the ambient light penetrating through the display screen, and therefore, the ambient light sensor is easily affected by the brightness of the display screen when detecting the ambient light, and accuracy of ambient light detection is affected. The display screen can be adjusted to be lower in brightness according to a certain dimming cycle so that the ambient light sensor can detect the ambient light. In order to improve the accuracy of ambient light detection, the length of the dimming period of the display screen is increased, and the duration of the display screen in dim light in each dimming period is increased. This affects the fingerprint sensor below the display screen to collect the fingerprint image, reducing the performance of fingerprint detection.
Disclosure of Invention
The embodiment of the application provides a fingerprint detection method, a fingerprint sensor and electronic equipment, so that the influence of the brightness change of a display screen on fingerprint detection is easier to reduce, and the fingerprint detection performance is improved.
In a first aspect, a method for fingerprint detection is provided, including:
receiving a synchronous signal of a display screen, wherein the synchronous signal is used for triggering a pixel array of a fingerprint sensor to perform exposure, the period of the synchronous signal is synchronous with a dimming period of the display screen, and the dimming period comprises a bright period and a dark period;
and based on the triggering of the synchronous signal, sequentially exposing pixels of each row of the pixel array so as to ensure that the exposure time in the pixel array is constant with the position of the pixel corresponding to the dark time period, wherein the data of the exposed pixels of each row are used for acquiring a fingerprint image.
In one possible implementation, the exposure time of a row of pixels in the pixel array is equal to an integer multiple of the dimming period.
In a possible implementation manner, the synchronization signal is a field synchronization signal output by the display screen, or the synchronization signal is another signal that maintains synchronization with the field synchronization signal.
In a possible implementation manner, a synchronization pin for connecting with the display screen is provided on the fingerprint sensor, and the receiving of the synchronization signal of the display screen of the electronic device includes: and receiving the synchronous signal output by the display screen through the synchronous pin.
In a possible implementation manner, the fingerprint sensor is connected to a host, and the receiving a synchronization signal of a display screen of an electronic device includes: receiving, by the host, the synchronization signal of the display screen.
In a possible implementation manner, the host is a processor of the electronic device, or the host is a Micro-programmed Control Unit (MCU) of the fingerprint sensor.
In a possible implementation manner, the sequentially exposing pixels in each row of the pixel array according to the synchronization signal includes: when the rising edge or the falling edge of the synchronous signal arrives, pixels of each row of the pixel array are exposed in sequence; alternatively, when a rising edge or a falling edge of the synchronization signal arrives, exposure is sequentially performed on pixels in each row of the pixel array after a delay of a specific time.
In one possible implementation, the dimming period is used for an ambient light sensor below the display screen to detect ambient light of the electronic device.
In a second aspect, there is provided a fingerprint sensor comprising a pixel array, and control circuitry coupled to the pixel array, the control circuitry being configured to:
receiving a synchronous signal of a display screen, wherein the synchronous signal is used for triggering a pixel array of a fingerprint sensor to perform exposure, the period of the synchronous signal is synchronous with a dimming period of the display screen, and the dimming period comprises a bright period and a dark period;
and controlling each row of pixels of the pixel array to be sequentially exposed based on the triggering of the synchronous signal so as to ensure that the exposure time in the pixel array is constant with the position of the pixel corresponding to the dark time period, wherein the data of each row of pixels after exposure is used for acquiring a fingerprint image.
In one possible implementation, the exposure time of a row of pixels in the pixel array is equal to an integer multiple of the dimming period.
In a possible implementation manner, the synchronization signal is a field synchronization signal output by the display screen, or the synchronization signal is another signal that maintains synchronization with the field synchronization signal.
In a possible implementation manner, a synchronization pin for connecting with the display screen is provided on the fingerprint sensor, and the receiving of the synchronization signal of the display screen of the electronic device includes: and receiving the synchronous signal output by the display screen through the synchronous pin.
In a possible implementation manner, the fingerprint sensor is connected to a host, and the receiving a synchronization signal of a display screen of an electronic device includes: receiving, by the host, the synchronization signal of the display screen.
In a possible implementation manner, the host is a processor of the electronic device, or the host is an MCU of the fingerprint sensor.
In a possible implementation manner, the sequentially exposing pixels in each row of the pixel array according to the synchronization signal includes: when the rising edge or the falling edge of the synchronous signal arrives, pixels of each row of the pixel array are exposed in sequence; alternatively, when a rising edge or a falling edge of the synchronization signal arrives, exposure is sequentially performed on pixels in each row of the pixel array after a delay of a specific time.
In a third aspect, an electronic device is provided, comprising a display screen; the ambient light sensor is arranged below the display screen; and a fingerprint sensor in any one of the implementations of the second aspect.
In one possible implementation, the ambient light sensor is configured to detect ambient light of the electronic device based on the dimming period.
Based on the technical scheme, when the display screen adjusts the brightness of the display screen based on the dimming cycle, the time ratio of the bright period to the dark period in the exposure time of different pixel rows in the pixel array of the fingerprint sensor is different, so that random horizontal stripes are generated in a fingerprint image formed based on the data of the pixel array. When the pixel array is exposed by using the synchronous signal of the display screen, the exposure time of the pixel array is always synchronous with the synchronous signal of the display screen, and the dimming cycle of the display screen is also synchronous with the synchronous signal, so that the positions of the pixels corresponding to the dark period and the bright period in the exposure time and the dimming cycle in the pixel array are constant, and the positions of the horizontal stripes are fixed. Thus, when the data of the pixel array after exposure is processed, the horizontal stripes with fixed positions can be eliminated by the fingerprint algorithm more easily, and the fingerprint detection performance is improved.
Drawings
Fig. 1 is a schematic diagram of a dimming cycle of a display.
Fig. 2 is a schematic diagram of exposing each row of pixels by using a progressive scanning exposure method.
Fig. 3 is a schematic diagram of a fingerprint image obtained when the exposure time of one row of pixels is an integer multiple of the dimming period.
Fig. 4 is a schematic diagram of a fingerprint image obtained when the exposure time of one row of pixels is a non-integral multiple of the dimming period.
Fig. 5 is a schematic flow chart of a method of fingerprint detection according to an embodiment of the present application.
Fig. 6 is a schematic diagram of the relationship between the dimming period and the field sync signal of the display screen.
FIG. 7 is a schematic diagram of one way in which the fingerprint sensor acquires synchronization signals for the display screen.
FIG. 8 is a schematic diagram of another way in which the fingerprint sensor acquires synchronization signals for the display screen.
Fig. 9 is a schematic diagram of a fingerprint sensor according to an embodiment of the present application.
Fig. 10 is a schematic diagram of one possible electronic device in an embodiment of the application.
Fig. 11 is a schematic block diagram of one possible fingerprint sensor according to an embodiment of the present application.
Fig. 12 is a schematic diagram of a possible optical path guiding structure in the embodiment of the present application.
Detailed Description
The technical solution in the present application will be described below with reference to the accompanying drawings.
The current electronic equipment pursues higher screen occupation ratio, and more front devices need to be moved below the screen, such as a proximity sensor, an ambient light sensor and the like. Especially, when the ambient light sensor is disposed below the display screen, the ambient light sensor needs to detect the light intensity of the ambient light penetrating through the display screen, and therefore, the ambient light sensor is very easily affected by the brightness of the display screen when detecting the ambient light, and accuracy of ambient light detection is affected. For this reason, in some display panels, in order to improve the accuracy of ambient light detection, the display mode of the display panel is changed, the length of the dimming cycle for adjusting the brightness of the display panel is increased (high duty ratio), and the duration of the dark period of the display panel in each dimming cycle is increased (high drop ratio). The display screen directly influences the collection of fingerprint images by the fingerprint sensor below the display screen by adjusting the brightness of the display screen, and the performance of fingerprint detection is reduced.
Such as the dimming cycle of a screen of the type shown in fig. 1, also referred to as a fall cycle, one dimming cycle comprising a bright period and a dark period. In the dimming cycle T1 shown in fig. 1, the signal intensity Vmax in the bright period is 1.07V, and the signal intensity Vmin in the dark period is 0.997V. Therefore, in the dark period of a dimming cycle, the display screen basically has no light output, and the ambient light sensor can not be influenced by the light intensity of the display screen, so that the light intensity of the ambient light where the electronic equipment is located at present can be detected more accurately. However, if the user needs to use the light emitted from the display screen to expose the pixel array of the fingerprint sensor for fingerprint detection, the display mode of the display screen will affect the fingerprint detection.
The fingerprint detection method provided by the embodiment of the application can be applied to fingerprint sensors adopting various exposure modes, and is particularly suitable for fingerprint sensors adopting a progressive scanning (RollingShutter) mode for exposure. Fig. 2 shows an exposure process of progressive scanning. The fingerprint sensor array includes M rows × N columns of pixels, and M ═ 7 is illustrated in fig. 2 as an example. As shown in fig. 2, the pixels in the same row in the pixel array are exposed at the same time, and after the exposure of the pixels in the row is started for a certain time, the pixels in the next row are exposed at the same time. Then, exposure is sequentially started for each subsequent row of pixels. The time difference between the start times of the exposures of two adjacent rows of pixels, for example, may be generally equal to the data reading time of one row of pixels, so that the reading times of the exposed data of different rows of pixels do not overlap. And then, processing the exposed data of the M rows of pixels, and splicing to form a complete image.
The exposure time of a row of pixels in the pixel array of the fingerprint sensor, for example, is typically above 30ms, and the exposed data for each pixel is actually an integral of the light signal it receives over that exposure time. The dimming period of the display screen is typically 16.6ms, 8.3ms, 4.1ms, etc., for example. It can be seen that the exposure time of a row of pixels is often greater than the dimming cycle of the display screen, the exposure is a process in which the pixels superimpose, i.e., integrate, light received in the exposure time, and if some pixel rows happen to dim the brightness of the display screen during the process of integrating the light, the pixel row cannot receive the light during the dark period of the dimming cycle, which results in a smaller data of the pixel row. In this way, the exposed data of each row of pixels is not flat for the entire pixel array, and horizontal streaks occur in the finally obtained image.
The number of horizontal stripes is typically equal to (M × t)/(1000ms/R), where M is the number of pixel rows in the pixel array; t is the exposure time of a row of pixels, and because the pixels in the same row are exposed simultaneously, t can also be said to be the exposure time of a single pixel; r is the refresh rate of the display screen, i.e. the scanning frequency of the field sync signal (also called vertical sync signal, referred to as Vsync signal) of the display screen. In the embodiment of the present application, the dimming period of the display screen and the scanning period of the Vsync signal may be in an integer multiple relationship, for example, the dimming period of the display screen and the scanning period of the Vsync signal may be preferably equal.
The exposure of the pixels is an integration process of light in the exposure time, when the exposure time of a row of pixels is integral multiple of the dimming cycle of the display screen, because the lengths of the bright period and the dark period contained in the exposure time of each pixel are equal, the levels of data obtained after the integration of the pixels in each row are basically consistent, and no horizontal stripe exists.
Fig. 3 shows a case where the exposure time of one row of pixels is equal to one dimming period. It can be seen that although each row of pixels undergoes dimming of the display screen within the exposure time, the bright period and the dark period of each row of pixels within the exposure time are equal in time, and therefore, the finally obtained fingerprint image does not have horizontal stripes.
Fig. 4 shows a case where the exposure time of one row of pixels is a non-integral multiple of the dimming period. The first row shows the dimming period T1, the next rows representing the exposure time for each row of pixels in the pixel array. It can be seen that the bright and dark periods experienced by different pixel rows during their exposure times are not equal in time, and therefore, significant horizontal streaks appear in the resulting fingerprint image. In addition, since the light adjustment operation of the display and the exposure process of the fingerprint sensor are independent of each other, the position of the horizontal stripe on the fingerprint image obtained at each fingerprint detection is also changed, and it is difficult to eliminate the horizontal stripe by using the subsequent fingerprint algorithm.
However, in practical applications, the exposure time for one line of pixels is set to be an integral multiple of the dimming period, which has the following problem. On one hand, because the dimming system and the fingerprint detection system of the display screen are two independent systems, and respective clocks are adopted, the jitter of the dimming period makes it difficult to ensure that the exposure time of a line of pixels is just integral multiple of the dimming period, so that the horizontal stripes cannot be completely eliminated. On the other hand, different types of fingerprint sensors have their own characteristics, and if the exposure times of the fingerprint sensors are intentionally configured to be equal, i.e., equal to integral multiples of the dimming period, the performance of different fingerprint detection chips cannot be optimized.
Therefore, the embodiment of the application provides a fingerprint detection method, so that the influence of the brightness change of a display screen on fingerprint detection is easier to reduce, and the fingerprint detection performance is improved.
Fig. 5 is a schematic flow chart of a method of fingerprint detection according to an embodiment of the present application. The method 500 shown in fig. 5 may be performed by a fingerprint sensor that includes a pixel array comprised of a plurality of pixels. As shown in fig. 5, the method 500 may include some or all of the following steps.
In step 510, a synchronization signal of a display screen is received.
Wherein the synchronous signal is used for triggering the pixel array of the fingerprint sensor to carry out exposure. The period of the synchronization signal is synchronized with a dimming period T1 of the display screen, the dimming period T1 including a bright period and a dark period.
It should be understood that the dimming period T1 is a period in which the brightness of the display screen is adjusted, and it is understood that the brightness of the display screen is adjusted once every time T1 elapses. Each dimming cycle T1 includes a bright period and a dark period. For example, it can be understood that the display screen is dimmed down every time T1 passes and for a certain duration, which is the dark period in the dimming cycle; alternatively, the display screen is dimmed up for a duration of time, i.e., the bright period of the dimming cycle, every time T1 passes. The method and the device do not limit the lengths of the bright time period and the dark time period, and do not limit the specific brightness of the display screen in the bright time period and the dark time period.
Alternatively, the dimming cycle may be used for an ambient light sensor below the display screen to detect ambient light of the electronic device. In other words, the dimming cycle may be used for the ambient light sensor to detect the ambient light of the electronic device. In particular, the ambient light sensor may detect ambient light in an environment in which the electronic device is currently located within a dark period of the dimming cycle based on the dimming cycle. I.e. the dimming period may be used as a basis for the ambient light sensor to detect the ambient light.
In step 520, based on the triggering of the synchronization signal, each row of pixels of the pixel array is sequentially exposed, so that the position of the pixel in the pixel array corresponding to the dark period and the exposure time are constant.
And the data of each row of exposed pixels is used for acquiring a fingerprint image.
In this embodiment, when the display screen adjusts the brightness of the fingerprint sensor based on the dimming cycle, the ratio of the bright period to the dark period encountered in the exposure time of different pixel rows in the pixel array of the fingerprint sensor is different, which results in the generation of random horizontal stripes in the fingerprint image formed based on the data of the pixel array. When the pixel array is exposed by using the synchronous signal of the display screen, the exposure time of the pixel array is always synchronous with the synchronous signal of the display screen, and the dimming cycle of the display screen is also synchronous with the synchronous signal, so that the positions of the pixels corresponding to the dark period and the bright period in the exposure time and the dimming cycle in the pixel array are constant, and the positions of the horizontal stripes are fixed. Thus, when the data of the pixel array after exposure is processed, the horizontal stripes with fixed positions can be eliminated by the fingerprint algorithm more easily, and the fingerprint detection performance is improved.
It should be noted here that the method of fingerprint detection according to the embodiment of the present application aims to make the position of the horizontal stripe appearing in the fingerprint image formed based on the data of the pixel array fixed, rather than randomly varied, at each fingerprint detection. Therefore, the fingerprint algorithm can be designed more easily to process the horizontal stripes by using the fingerprint algorithm, so that the influence of the horizontal stripes on the fingerprint detection result is eliminated.
The synchronization signal of the display screen may be a field synchronization signal of the display screen; or other signals that maintain synchronization with the field sync signal, such as a line sync signal (referred to as Hsync signal) corresponding to a specific pixel line.
Fig. 6 shows the relationship between the dimming period and the field sync signal of the display screen. Assume that the Vsync signal of the display screen is used as a synchronization signal for triggering the pixel array to perform exposure, and the dimming period of the display screen is equal to the scanning period of the Vsync signal of the display screen. As can be seen from fig. 6, the dimming period of the display screen and the scanning period of the Vsync signal of the display screen are synchronized, i.e., the phase difference between the dimming period of the display screen and the scanning period of the Vsync signal of the display screen is constant.
Then, when the pixel array is triggered to be exposed by the Vsync signal of the display screen, the exposure time of the pixel array and the dimming period of the display screen are also kept synchronous, i.e., the phase difference between the exposure time of the pixel array and the dimming period of the display screen is constant. In this way, in the pixel array, the position of the pixel whose exposure time corresponds to the dark period in the dimming cycle is constant, or in other words, the position of the pixel whose exposure time corresponds to the bright period in the dimming cycle is constant, so that the position of the horizontal stripe described above is always fixed.
When fingerprint detection is performed, generally, after light spots for fingerprint detection on a display screen are lightened, a fingerprint sensor starts to sequentially expose each row of pixels in a pixel array; when the fingerprint detection method of the embodiment of the application is adopted, during fingerprint detection, after light spots for fingerprint detection on the display screen are lightened, the fingerprint sensor needs to wait for the arrival of a Vsync signal of the display screen to start to sequentially expose each row of pixels in the pixel array.
In the embodiment of the present application, the exposure time of a row of pixels and the dimming period may or may not be an integer multiple. Preferably, the exposure time of a row of pixels may be configured to be equal to an integer multiple of the dimming period, such as 1.
In step 510, the fingerprint sensor may receive a synchronization signal of the display screen in the following two ways.
In one implementation, a synchronization pin for connecting with the display screen may be disposed on the fingerprint sensor, and then, in step 510, the fingerprint sensor may receive a synchronization signal of the display screen through the synchronization pin.
For example, as shown in fig. 7, the fingerprint sensor is connected to the display screen through a newly added synchronization pin, and may directly receive a synchronization signal output by the display screen to the fingerprint sensor for triggering the pixel array to perform exposure. The fingerprint sensor and the host may communicate based on a Serial Peripheral Interface (SPI), for example, to receive commands from the host to perform operations related to fingerprint detection and upload acquired data of the pixel array to the host. The host may also provide POWER (POWER) to the fingerprint sensor and send a Reset Signal (RST) to the fingerprint sensor, etc.
In the embodiment of the present application, the host may be a processor of an electronic device, for example, a processor in a Personal Computer (PC) or a mobile PHONE (PHONE), such as a main control; the host may also be a micro control unit, such as a MCU of a fingerprint sensor.
In another implementation, since the fingerprint sensor is connected to the host, the fingerprint sensor may receive a synchronization signal of the display screen through the host in step 510.
For example, as shown in fig. 8, the fingerprint sensor does not need to be directly connected to the display screen, and the synchronization signal output by the display screen can be transmitted to the fingerprint sensor through the host computer. When the fingerprint sensor acquires the synchronous signal of the display screen in an indirect mode, because the communication delay between the fingerprint sensor and the host is constant, when the fingerprint sensor exposes the pixel array based on the synchronous signal of the display screen, the exposure time is still kept synchronous with the synchronous signal of the display screen, namely kept synchronous with the dimming period of the display screen, and cannot be influenced by the delay.
In step 520, the fingerprint sensor may sequentially expose each row of pixels of the pixel array in the following two ways.
In one implementation, the fingerprint sensor may start sequentially exposing each row of pixels of the pixel array when a rising edge or a falling edge of the synchronization signal arrives.
In another implementation, the fingerprint sensor may start to sequentially expose each row of pixels of the pixel array after a certain time delay when a rising edge or a falling edge of the synchronization signal arrives.
In either case, as long as the exposure time is synchronized with the synchronization signal of the display screen, the exposure time can be made constant with respect to the position of the pixel corresponding to the dark period and the position of the pixel corresponding to the bright period in the dimming cycle, thereby ensuring that the position of the horizontal stripe is fixed as described above. Thus, when the data of the pixel array after exposure is processed, the horizontal stripes with fixed positions can be eliminated by the fingerprint algorithm more easily, and the fingerprint detection performance is improved.
The embodiment of the application also provides a fingerprint sensor, which can also be called as a fingerprint chip, a sensor chip and the like. The fingerprint sensor may perform the method of fingerprint detection in any of the embodiments described above, and reference may be made to the description of the method of fingerprint detection described above for a detailed description of the fingerprint sensor.
As shown in fig. 9, the fingerprint sensor 900 includes a pixel array 901, and a control circuit 902 connected to the pixel array 901, the control circuit 902 is configured to:
receiving a synchronization signal of a display screen, where the synchronization signal is used to trigger the pixel array 901 to perform exposure, where a cycle of the synchronization signal is synchronized with a dimming cycle of the display screen, and the dimming cycle includes a bright period and a dark period;
based on the triggering of the synchronization signal, pixels in each row of the pixel array 901 are controlled to be sequentially exposed, so that the exposure time in the pixel array 901 is constant with the position of the pixel corresponding to the dark period, wherein the data of the exposed pixels in each row is used for acquiring a fingerprint image.
Optionally, in an implementation, the exposure time of a row of pixels in the pixel array 901 is equal to an integer multiple of the dimming period.
Optionally, in an implementation manner, the synchronization signal is a field synchronization signal output by the display screen, or the synchronization signal is another signal that maintains synchronization with the field synchronization signal.
Optionally, in an implementation manner, a synchronization pin for connecting with the display screen is provided on the fingerprint sensor 900, and the receiving a synchronization signal of the display screen of the electronic device includes: and receiving the synchronous signal output by the display screen through the synchronous pin.
Optionally, in an implementation manner, the fingerprint sensor 900 is connected to a host, and the receiving a synchronization signal of a display screen of the electronic device includes: receiving, by the host, the synchronization signal of the display screen.
Optionally, in an implementation manner, the host is a processor of the electronic device, or the host is an MCU of the fingerprint sensor 900.
Optionally, in an implementation manner, the sequentially exposing, according to the synchronization signal, each row of pixels of the pixel array 901 includes: when the rising edge or the falling edge of the synchronization signal arrives, pixels in each row of the pixel array 901 start to be sequentially exposed; alternatively, when the rising edge or the falling edge of the synchronization signal arrives, exposure is sequentially started for each row of pixels of the pixel array 901 after a delay of a certain time.
The embodiment of the application also provides electronic equipment, which comprises a display screen; the ambient light sensor is arranged below the display screen; and a fingerprint sensor as described in any of the above embodiments.
Optionally, in an implementation, the ambient light sensor is configured to detect ambient light of the electronic device based on the dimming cycle.
Fig. 10 and 11 show a possible structure of the fingerprint sensor according to the embodiment of the present application. Fig. 10 is an orientation diagram of the electronic device 10, and fig. 11 is a partial cross-sectional diagram of the electronic device 10 shown in fig. 10 along a direction a-a'. The electronic device 10 includes a display screen 120, an ambient light sensor disposed below the display screen 120, and a fingerprint sensor 900.
As shown in fig. 11, the fingerprint sensor 900 includes a light detecting portion 910 and a light path guiding structure 903. The optical path guiding structure 903 is disposed above the light detecting portion 910. The light detection section 910 includes a pixel array 901 composed of a plurality of pixels 9011, a control circuit 902 connected to the pixel array 901, and the like. As shown in fig. 10, the area where the pixel array 901 is located or the sensing area thereof is the fingerprint detection area 103 of the fingerprint sensor 900. The optical path guiding structure 903 is used to guide an optical signal returned by the finger on the fingerprint detection area 103 to the pixel array 901.
The embodiment of the present application does not limit the optical path guiding structure 903 in the fingerprint sensor 900. For example, the optical path directing structure 903 may include a microlens array composed of a plurality of microlenses. Further, at least one light blocking layer may be further disposed below the microlens array, wherein each light blocking layer is provided with a plurality of openings corresponding to the plurality of microlenses, respectively, and the pixel array 901 includes a plurality of pixels 9011 corresponding to the plurality of microlenses. Each microlens is configured to converge an optical signal returned by a finger to a corresponding opening in each light-blocking layer, so that the optical signal sequentially passes through the corresponding opening in each light-blocking layer and is transmitted to a corresponding pixel 9011 in the pixel array 901.
For another example, the optical path guiding structure 903 may include a collimator layer fabricated on a semiconductor silicon wafer, and having a plurality of collimating elements or a micro-hole array, where the collimating elements may be small holes.
For another example, the optical path directing structure 903 may include an optical lens layer having one or more lens units, which may be a lens group consisting of one or more aspheric lenses. For example, as shown in fig. 12, the optical path directing structure may include a lens 9031. Light emitted by the light emitting layer 1201 in the display screen illuminates a finger and returns through the finger can be converged to the pixel array 901 of the optical fingerprint sensor through the lens 9031.
When fingerprint detection is performed, the display screen 120 emits a beam of light 111 to the finger 140 above the fingerprint detection area 103, and the light 111 is reflected on the surface of the finger 140 to form reflected light or scattered light is formed by scattering inside the finger 140. Since the ridges 141 and valleys 142 of the fingerprint have different light reflection capabilities, the reflected light 151 from the ridges and the reflected light 152 from the valleys have different light intensities, and the reflected light is received by the pixel array 901 and converted into corresponding electrical signals, i.e., fingerprint detection signals, after passing through the optical path guiding structure 903. Based on the fingerprint detection signal, data of the fingerprint image can be obtained and further used for fingerprint matching and verification, so that the function of optical fingerprint detection is realized in the electronic device 10.
Further, the electronic device 10 may also include an excitation light source for fingerprint detection.
The display screen 120 may be a display screen having a self-Emitting display unit, such as an Organic Light-Emitting Diode (OLED) display screen or a Micro-LED (Micro-LED) display screen. Taking the OLED display screen as an example, the fingerprint sensor 900 may use the display unit located in the fingerprint detection area 103 of the OLED display screen 120 as an excitation light source for optical fingerprint detection.
By way of example and not limitation, the electronic device in the embodiments of the present application may be a portable or mobile computing device such as a terminal device, a mobile phone, a tablet computer, a notebook computer, a desktop computer, a game device, an in-vehicle electronic device, or a wearable smart device, and other electronic devices such as an electronic database, an automobile, and an Automated Teller Machine (ATM). This wearable smart machine includes that the function is complete, the size is big, can not rely on the smart mobile phone to realize complete or partial functional equipment, for example smart watch or smart glasses etc to and include only be concentrated on a certain kind of application function and need with other equipment like the equipment that the smart mobile phone cooperation was used, for example all kinds of intelligent bracelet, intelligent ornament etc. that carry out the physical sign monitoring.
It should be noted that, without conflict, the embodiments and/or technical features in the embodiments described in the present application may be arbitrarily combined with each other, and the technical solutions obtained after the combination also fall within the protection scope of the present application.
The system, apparatus and method disclosed in the embodiments of the present application can be implemented in other ways. For example, some features of the method embodiments described above may be omitted or not performed. The above-described device embodiments are merely illustrative, the division of the unit is only one logical functional division, and there may be other divisions when the actual implementation is performed, and a plurality of units or components may be combined or may be integrated into another system. In addition, the coupling between the units or the coupling between the components may be direct coupling or indirect coupling, and the coupling includes electrical, mechanical or other connections.
It should be understood that the specific examples in the embodiments of the present application are for the purpose of promoting a better understanding of the embodiments of the present application, and are not intended to limit the scope of the embodiments of the present application, and that various modifications and variations can be made by those skilled in the art based on the above embodiments and fall within the scope of the present application.
The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.
Claims (17)
1. A method of fingerprint detection, the method comprising:
receiving a synchronous signal of a display screen, wherein the synchronous signal is used for triggering a pixel array of a fingerprint sensor to perform exposure, the period of the synchronous signal is synchronous with a dimming period of the display screen, and the dimming period comprises a bright period and a dark period;
and based on the triggering of the synchronous signal, sequentially exposing pixels of each row of the pixel array so as to ensure that the exposure time in the pixel array is constant with the position of the pixel corresponding to the dark time period, wherein the data of the exposed pixels of each row are used for acquiring a fingerprint image.
2. The method of claim 1, wherein an exposure time of a row of pixels in the pixel array is equal to an integer multiple of the dimming period.
3. The method according to claim 1 or 2, wherein the synchronization signal is a field synchronization signal output by the display screen, or the synchronization signal is another signal that maintains synchronization with the field synchronization signal.
4. The method according to claim 1 or 2, wherein a synchronization pin for connecting with the display screen is disposed on the fingerprint sensor, and the receiving of the synchronization signal of the display screen of the electronic device comprises:
and receiving the synchronous signal output by the display screen through the synchronous pin.
5. The method according to claim 1 or 2, wherein the fingerprint sensor is connected to a host, and the receiving of the synchronization signal of the display screen of the electronic device comprises:
receiving, by the host, the synchronization signal of the display screen.
6. The method of claim 5, wherein the host is a processor of the electronic device or a Micro Control Unit (MCU) of the fingerprint sensor.
7. The method according to claim 1 or 2, wherein the sequentially exposing each row of pixels of the pixel array according to the synchronization signal comprises:
when the rising edge or the falling edge of the synchronous signal arrives, pixels of each row of the pixel array are exposed in sequence; alternatively, the first and second electrodes may be,
and when the rising edge or the falling edge of the synchronous signal arrives, delaying for a specific time, and then sequentially exposing each row of pixels of the pixel array.
8. The method of claim 1 or 2, wherein the dimming cycle is used for an ambient light sensor below the display screen to detect ambient light of the electronic device.
9. A fingerprint sensor comprising a pixel array and control circuitry coupled to the pixel array, the control circuitry being configured to:
receiving a synchronous signal of a display screen, wherein the synchronous signal is used for triggering a pixel array of a fingerprint sensor to perform exposure, the period of the synchronous signal is synchronous with a dimming period of the display screen, and the dimming period comprises a bright period and a dark period;
and controlling each row of pixels of the pixel array to be sequentially exposed based on the triggering of the synchronous signal so as to ensure that the exposure time in the pixel array is constant with the position of the pixel corresponding to the dark time period, wherein the data of each row of pixels after exposure is used for acquiring a fingerprint image.
10. The fingerprint sensor of claim 9, wherein an exposure time of a row of pixels in the pixel array is equal to an integer multiple of the dimming period.
11. The fingerprint sensor of claim 9 or 10, wherein the synchronization signal is a field synchronization signal output by the display screen, or another signal that maintains synchronization with the field synchronization signal.
12. The fingerprint sensor according to claim 9 or 10, wherein a synchronization pin for connecting with the display screen is disposed on the fingerprint sensor, and the fingerprint sensor receives a synchronization signal of the display screen of the electronic device, and comprises:
and receiving the synchronous signal output by the display screen through the synchronous pin.
13. The fingerprint sensor of claim 9 or 10, wherein the fingerprint sensor is connected to a host, and the receiving of the synchronization signal of the display screen of the electronic device comprises:
receiving, by the host, the synchronization signal of the display screen.
14. The fingerprint sensor of claim 13, wherein the host is a processor of the electronic device or a Micro Control Unit (MCU) of the fingerprint sensor.
15. The fingerprint sensor of claim 9 or 10, wherein the sequentially exposing each row of pixels of the pixel array according to the synchronization signal comprises:
when the rising edge or the falling edge of the synchronous signal arrives, pixels of each row of the pixel array are exposed in sequence; alternatively, the first and second electrodes may be,
and when the rising edge or the falling edge of the synchronous signal arrives, delaying for a specific time, and then sequentially exposing each row of pixels of the pixel array.
16. An electronic device, comprising:
a display screen;
the ambient light sensor is arranged below the display screen; and the number of the first and second groups,
the fingerprint sensor of any one of claims 9 to 15.
17. The electronic device of claim 16, wherein the ambient light sensor is configured to detect ambient light of the electronic device based on the dimming period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011511799.2A CN112668425B (en) | 2020-12-18 | 2020-12-18 | Fingerprint detection method, fingerprint sensor and electronic equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011511799.2A CN112668425B (en) | 2020-12-18 | 2020-12-18 | Fingerprint detection method, fingerprint sensor and electronic equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112668425A true CN112668425A (en) | 2021-04-16 |
| CN112668425B CN112668425B (en) | 2022-11-01 |
Family
ID=75407246
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011511799.2A Active CN112668425B (en) | 2020-12-18 | 2020-12-18 | Fingerprint detection method, fingerprint sensor and electronic equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112668425B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113361416A (en) * | 2021-06-08 | 2021-09-07 | 深圳市汇顶科技股份有限公司 | Method and device for collecting fingerprint image and electronic equipment |
| CN114998943A (en) * | 2021-12-24 | 2022-09-02 | 荣耀终端有限公司 | Data acquisition method and electronic equipment |
| WO2022257027A1 (en) * | 2021-06-08 | 2022-12-15 | 深圳市汇顶科技股份有限公司 | Method and apparatus for collecting fingerprint image and electronic device |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101203084A (en) * | 2006-12-12 | 2008-06-18 | 美国凹凸微系有限公司 | Power supply circuit for LCD backlight and method thereof |
| CN103489429A (en) * | 2012-06-11 | 2014-01-01 | 联想(北京)有限公司 | Method for adjusting brightness and electronic equipment |
| CN104184954A (en) * | 2013-05-27 | 2014-12-03 | 原相科技股份有限公司 | Optical detection device and synchronous adjustment method thereof |
| CN109255278A (en) * | 2017-07-12 | 2019-01-22 | 上海耕岩智能科技有限公司 | A kind of method and apparatus of synchronous acquisition finger print information |
| CN109891429A (en) * | 2018-12-26 | 2019-06-14 | 深圳市汇顶科技股份有限公司 | Fingerprint identification device and fingerprint identification method |
| CN110945526A (en) * | 2019-10-25 | 2020-03-31 | 深圳市汇顶科技股份有限公司 | Method and device for collecting fingerprint under screen, electronic equipment and storage medium |
| CN110956939A (en) * | 2019-11-27 | 2020-04-03 | 华为技术有限公司 | Method for adjusting screen brightness and electronic equipment |
| CN111164607A (en) * | 2019-07-12 | 2020-05-15 | 深圳市汇顶科技股份有限公司 | Fingerprint detection device and electronic equipment |
| CN111898415A (en) * | 2020-06-16 | 2020-11-06 | 浙江大学 | Method and device for imaging fingerprints under screen and electronic equipment |
-
2020
- 2020-12-18 CN CN202011511799.2A patent/CN112668425B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101203084A (en) * | 2006-12-12 | 2008-06-18 | 美国凹凸微系有限公司 | Power supply circuit for LCD backlight and method thereof |
| CN103489429A (en) * | 2012-06-11 | 2014-01-01 | 联想(北京)有限公司 | Method for adjusting brightness and electronic equipment |
| CN104184954A (en) * | 2013-05-27 | 2014-12-03 | 原相科技股份有限公司 | Optical detection device and synchronous adjustment method thereof |
| CN109255278A (en) * | 2017-07-12 | 2019-01-22 | 上海耕岩智能科技有限公司 | A kind of method and apparatus of synchronous acquisition finger print information |
| CN109891429A (en) * | 2018-12-26 | 2019-06-14 | 深圳市汇顶科技股份有限公司 | Fingerprint identification device and fingerprint identification method |
| CN111164607A (en) * | 2019-07-12 | 2020-05-15 | 深圳市汇顶科技股份有限公司 | Fingerprint detection device and electronic equipment |
| CN110945526A (en) * | 2019-10-25 | 2020-03-31 | 深圳市汇顶科技股份有限公司 | Method and device for collecting fingerprint under screen, electronic equipment and storage medium |
| CN110956939A (en) * | 2019-11-27 | 2020-04-03 | 华为技术有限公司 | Method for adjusting screen brightness and electronic equipment |
| CN111898415A (en) * | 2020-06-16 | 2020-11-06 | 浙江大学 | Method and device for imaging fingerprints under screen and electronic equipment |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113361416A (en) * | 2021-06-08 | 2021-09-07 | 深圳市汇顶科技股份有限公司 | Method and device for collecting fingerprint image and electronic equipment |
| WO2022257027A1 (en) * | 2021-06-08 | 2022-12-15 | 深圳市汇顶科技股份有限公司 | Method and apparatus for collecting fingerprint image and electronic device |
| CN114998943A (en) * | 2021-12-24 | 2022-09-02 | 荣耀终端有限公司 | Data acquisition method and electronic equipment |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112668425B (en) | 2022-11-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112668425B (en) | Fingerprint detection method, fingerprint sensor and electronic equipment | |
| CN107346152B (en) | Display device, display screen and terminal | |
| US11188729B2 (en) | Display panel, fingerprint identification display module and fingerprint identification method | |
| US10909916B2 (en) | OLED array substrate, OLED display panel, pixel circuit, driving method and method for fingerprint recognition using OLED display panel | |
| CN109521605B (en) | Backlight module and display device | |
| US9946386B2 (en) | Display panel for detecting biometric information and driving method thereof | |
| CN109696192B (en) | Optical biometric sensor with automatic gain and exposure control | |
| US8368663B2 (en) | Touch sensing using shadow and reflective modes | |
| CN110870072A (en) | Image sensor including light-shielding member for blocking interference between plurality of light-receiving sensors, and electronic device including the same | |
| CN101642372B (en) | Biometrics authentication system | |
| CN109376616B (en) | Fingerprint identification device, fingerprint identification method thereof and display device | |
| CN108287634A (en) | Touch display panel, display device and driving method of touch display panel | |
| US20150083917A1 (en) | Infrared light director for gesture or scene sensing fsc display | |
| US20140168164A1 (en) | Multi-dimensional touch input vector system for sensing objects on a touch panel | |
| CN110770748B (en) | Optical fingerprint identification device, electronic equipment and fingerprint identification method | |
| CN110036397A (en) | The method, apparatus and terminal device of fingerprint recognition | |
| US20180288301A1 (en) | Image Sensing Device and Sensing Method Using the Same | |
| CN210605736U (en) | Fingerprint detection device, display screen and electronic equipment | |
| CN110738199A (en) | display device and its driving method | |
| CN113380186B (en) | Display panel and display device | |
| CN110969146B (en) | Fingerprint identification component, display substrate, display panel and fingerprint identification method | |
| EP4064115A1 (en) | Fingerprint detection method, fingerprint sensor and electronic device | |
| CN110969126A (en) | Display device | |
| CN112400172B (en) | Texture image acquisition method, texture image acquisition circuit and display panel | |
| CN112883903B (en) | Display panel driving method and display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |