TW201322048A - Field depth change detection system, receiving device, field depth change detecting and linking system - Google Patents

Abstract

A field depth change detecting and linking system is disclosed, which is suitable for detecting an object under detection disposed on a detection plane, and includes a transmission device for transmitting a light signal that twinkles based on a first frequency to the detection plane, a receiving device, and a linking device. The receiving device includes a light sensing array for receiving the light signal from the detection plane and generating a plurality of sensing signals; a filtering unit for receiving each sensing signal and filtering out the component of its background noise so as to output an identifying signal; and a processing unit for receiving each identifying signal generated from the light sensing array and estimating a field depth change. The linking device is electrically connected to the processing unit for generating a virtual image signal related to the motion change of the object under detection.

Description

Depth of field change detection system, receiving device, depth of field change detection and linkage system

The invention relates to a detection and linkage system, in particular to a depth of field change detection and linkage system for an interactive game.

Referring to FIG. 1 , a depth of field identification system including a transmitting device Tx and a receiving device Rx for detecting a depth of field of a detecting object 11 (for example, a hand in the drawing) from the receiving device Rx is provided. (Z ₁ , Z ₂ ).

The transmitting device Tx includes a light source transmitter 12 for transmitting a laser light and a lens 13 for penetrating the laser light. The laser light passes through the lens 13 to reach the detecting object 11, and the detecting device a plurality of laser speckles 14 are formed on the object 11, and the pattern of the laser speckles 14 is related to the depth of field distance, that is, the depth of field distance Z ₂ >Z ₁ , the laser speckle 14 ′ is larger than the laser beam Spot 14.

The receiving device Rx' includes another lens 15 for collecting light, an image sensing array 16 and an image processing unit (not shown). The image sensing array 16 includes a plurality of sensing units 161, each sensing unit 161 is configured to receive incident light at a location thereof, and the sensing units 161 respectively generate a plurality of image sensing related to the incident light. Signal. The image processing unit is electrically connected to the image sensing array 16 and receives the image sensing signals, and determines the depth of field distance by recognizing the patterns of the laser speckles 14 formed on the detecting object 11.

A disadvantage of this depth of field identification system is that the interference of the background light noise makes the size of the laser speckles 14, 14' obscured and causes a false positive.

Accordingly, a first object of the present invention is to provide a depth of field change detection and linkage system that is unaffected by background light noise.

Therefore, the depth of field detection and linkage system of the present invention is suitable for detecting a detection object located in a detection plane, the detection plane includes a plurality of detection areas, and the detection object includes a plurality of optical signals that can reflect light. The parts, and each part is located in the corresponding detection area.

The depth of field change detection and linkage system comprises a transmitting device, a receiving device and a linkage device.

The transmitting device is configured to transmit, to the detecting plane, a transmitting optical signal that is blinked according to a first frequency, and the transmitted optical signal reflected by the static portion of the detecting object is maintained at the first frequency, and is The transmitted optical signal reflected by the dynamic portion of the detected object is frequency shifted to another second frequency.

The receiving device comprises a light sensing array, a filtering unit and a processing unit.

The light sensing array has a plurality of light sensing units respectively corresponding to the detecting regions of the detecting plane, and each of the light sensing units is configured to receive the light signals from the corresponding detecting regions and generate a sense Test signal.

The filtering unit is electrically connected to the light sensing array for receiving each sensing signal, and the filtering unit has a passband covering the first frequency and the second frequency, and a background noise is covered The frequency of the band is stopped and a filtered identification signal is output.

The processing unit is electrically connected to the filtering unit for receiving each identification signal generated by the optical sensing array, and determining a frequency of a maximum amplitude component in a spectrum of each identification signal, and frequency of the maximum amplitude component As a second frequency.

The processing unit estimates the detection object by using the second frequency of each of the identification signals as compared with a difference between the first frequency and the detection area corresponding to the light sensing unit from which the identification signal is derived. Each portion varies with respect to a depth of field of the light sensing unit.

The linking device is configured to generate a virtual image signal and is electrically connected to the receiving device to receive the signal indicating the change of the depth of field, and the virtual image signal is used to present a virtual space and a virtual object, and the virtual object is The actions in the virtual space are related to this depth of field change.

A second object of the present invention is to provide a depth of field detection system that is unaffected by background light noise.

Therefore, the depth of field detection system of the present invention is suitable for detecting a detection object located in a detection plane, the detection plane includes a plurality of detection areas, and the detection object includes a plurality of parts that can reflect optical signals. And each part is located in the corresponding detection area.

The depth of field change detection system includes a transmitting device, a receiving device and a linkage device.

The transmitting device is configured to transmit, to the detecting plane, a transmitting optical signal that is blinked according to a first frequency, and the transmitted optical signal reflected by the static portion of the detecting object is maintained at the first frequency, and is The transmitted optical signal reflected by the dynamic portion of the detected object is frequency shifted to another second frequency.

The receiving device comprises a light sensing array, a filtering unit and a processing unit.

The light sensing array has a plurality of light sensing units respectively corresponding to the detecting regions of the detecting plane, and each of the light sensing units is configured to receive the light signals from the corresponding detecting regions and generate a sense Test signal.

The filtering unit is electrically connected to the light sensing array for receiving each sensing signal, and the filtering unit has a passband covering the first frequency and the second frequency, and a background noise is covered The frequency of the band is stopped and a filtered identification signal is output.

The processing unit is electrically connected to the filtering unit for receiving each identification signal generated by the optical sensing array, and determining a frequency of a maximum amplitude component in a spectrum of each identification signal, and frequency of the maximum amplitude component As a second frequency.

The processing unit estimates the detection object by using the second frequency of each of the identification signals as compared with a difference between the first frequency and the detection area corresponding to the light sensing unit from which the identification signal is derived. Each portion varies with respect to a depth of field of the light sensing unit.

A third object of the present invention is to provide a receiving device that is unaffected by background light noise and that can be used in a portable product.

Therefore, the receiving device of the present invention is suitable for detecting a detecting object located in a detecting plane, the detecting plane includes a plurality of detecting regions, and the detecting object includes a plurality of portions capable of reflecting optical signals, and each of the detecting objects Each of the locations is located in the corresponding detection area, and the transmitting device is configured to transmit a transmitted light signal that is blinked according to a first frequency toward the detection plane.

The receiving device comprises a light sensing array, a filtering unit and a processing unit.

The light sensing array has a plurality of light sensing units respectively corresponding to the detecting regions of the detecting plane, and each of the light sensing units is configured to receive the light signals from the corresponding detecting regions and generate a sense Test signal.

The filtering unit is electrically connected to the light sensing array for receiving each sensing signal, and the filtering unit has a passband covering the first frequency and the second frequency, and a background noise is covered The frequency of the band is stopped and a filtered identification signal is output.

The processing unit is electrically connected to the filtering unit for receiving each identification signal generated by the optical sensing array, and determining a frequency of a maximum amplitude component in a spectrum of each identification signal, and frequency of the maximum amplitude component As a second frequency.

The processing unit estimates the detection object by using the second frequency of each of the identification signals as compared with a difference between the first frequency and the detection area corresponding to the light sensing unit from which the identification signal is derived. Each portion varies with respect to a depth of field of the light sensing unit.

The effect of the present invention is that, by using the difference between the second frequency and the first frequency different from the background optical noise frequency, the depth of field change can be judged without being affected by the background light noise, and is provided Used by the linkage system.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention.

Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to FIG. 2 and FIG. 3, a preferred embodiment of the depth of field change detection and linkage system of the present invention is applicable to detecting a detector 3 located in a detection plane 2, and the detection plane 2 includes a plurality of detections. In the area 21, the detector 3 includes a plurality of locations 31 for reflecting optical signals, and each of the locations 31 is located in the corresponding detection area 21. The depth of field change detecting and linking system comprises a transmitting device 4, a receiving device 5 and a linking device 6.

The transmitting device 4 is configured to transmit a transmitted light signal that is blinked according to a first frequency to the detecting plane 2, and the blinking frequency of the transmitted optical signal reflected by the static portion 31 of the detecting object 3 is maintained as the first At a frequency, the blinking frequency of the transmitted optical signal reflected by the dynamic portion 31 of the detector 3 is frequency shifted to another second frequency. For example, the transmitted light signal is from a light emitting diode (not shown), and the light emitting diode alternately flashes according to the first frequency to generate the transmitted light signal.

Referring to FIG. 3 and FIG. 4 , the receiving device 5 includes a light sensing array 51 , a vertical scanning circuit 52 , a horizontal scanning circuit 53 , a filtering unit 54 , and a processing unit 55 .

The light sensing array 51 has M×N (M 1. N>1) light sensing units 511-ij respectively corresponding to M×N detection areas 21-ij (i=1, . . . , M, j=1, . . . , N) of the plane 2 are detected. Each of the light sensing units 511-ij is configured to receive an optical signal from the corresponding detection area 21-ij and generate a corresponding sensing signal S _ij .

In the preferred embodiment, each of the light sensing units 511-ij of the light sensing array 51 is in a CMOS process, and the light sensing array 51 is subjected to the vertical scanning circuit 52 and the horizontal scanning circuit 53. Controlling, the sensing signals S ₁₁ ~S _{MN of the} light sensing units 511-11~511- _MN are sequentially output.

The filtering unit 54 is electrically connected to the light sensing array 51 for receiving each sensing signal, and the filtering unit 54 has a passband covering the first frequency and the second frequency, and a cover light The frequency of the noise is stopped and a filtered identification signal is output.

In more detail, the sensing signals generated by the optical signals from the detecting regions 21 in which the detecting object 3 is located have the components of the background optical noise and the components of the transmitted optical signals, but The frequency of the background optical noise is different and is away from the first frequency (for example, 500 MHz) of the transmitted optical signal. Therefore, the frequency band of the passband and the stop band of the filtering unit 54 can be designed, so that the frequency of the background optical noise is located. The tape is filtered out by the stop band. However, due to the Doppler effect, the detector 3 is reflected by the detector 3 to the light sensing unit when the displacement of the detector 3 is not zero. The blinking frequency of the transmitted optical signal of 511 is shifted from the original first frequency to another second frequency, and the passband of the filtering unit 54 is obtained in order to capture the portion related to the transmitted optical signal. Different frequency band ranges must be selected depending on the application such that the second frequency is located in the pass band of the filtering unit 54. For example, when the preferred embodiment is applied to an interactive game, two second frequencies f _{2 (max)} can be respectively estimated according to the maximum positive and negative displacement speeds that the human body (ie, the detector 3) can achieve. , f _{2 (min)} , and correspondingly, as shown in FIG. 5, the frequency band of the pass band of the filtering unit 54 is designed to cover the two second frequencies f _{2 (max)} and f _{2 (min)} , and The remaining band range other than the pass band BW is the stop band.

The processing unit 55 is electrically connected to the vertical scanning circuit 52, the horizontal scanning circuit 53 and the filtering unit 54, and performs a detecting method to determine that: a. the detecting object 3 is projected on the detecting plane 2 Positional distribution; b. Each portion 31 of the detector 3 changes with respect to a depth of field of the light sensing unit 511. Here, the "depth of field change" means that the portion 31 located in the detecting area 21-ij is opposite. a displacement speed of the light sensing unit 511-ij, and a moving distance is obtained by integrating the unit depth change with a depth of field change, and the unit time is the vertical and horizontal scanning circuits 52, 53 twice in succession. The time interval between the same one of the light sensing units 511-ij is selected.

Referring to Figures 3, 4 and 6, the detection method comprises the following steps 91-94.

Step 91: Receive and store each identification signal D _ij (i=1, 2, . . . , M, j=1, 2, . . . , N), the vertical scanning signal X _i and the horizontal scanning signal by using the processing unit 53 Y _j , and from the vertical scanning signal X _i and the horizontal scanning signal Y _{j ,} it is determined from which light sensing unit 511 - ij each of the identification signals is generated and output via the filtering unit 54 .

For example, the vertical scanning signal X _i=1 and the horizontal scanning signal Y _j=1 means that the identification signal D _ij=11 is generated from the light sensing unit 511-11 and output via the filtering unit 54, ... The vertical scanning signal X _i=M and the horizontal scanning signal Y _j=N represent that the identification signal D _ij=MN is generated from the light sensing unit 511-MN and output through the filtering unit 54.

Step 92: The processing unit 55 determines the frequency and amplitude of a maximum amplitude component in the spectrum of each identification signal (see FIG. 5), and uses the frequency of the maximum amplitude component as a second frequency, and the maximum amplitude. The amplitude value of the component is used as an identification amplitude value for each identification signal.

Step 93: Use the processing unit 55 Δ f D _ij identification signals each according to the second frequency f ₂ is compared to the difference between a first frequency f ₁ is stored in advance = f ₂ - f _1, and the identification The detection area 21-ij corresponding to the light sensing unit 511- _ij from the signal D _ij estimates a depth of field change of each portion 31 of the detector 3 relative to the light sensing unit 511-ij.

For example, the first frequency (see the frequency of the transmitted optical signal transmitted by the transmitting device 4 of FIG. 2) is 500 MHz, if the second frequency of the identification signal D _ij from the light sensing unit 511-ij is 525 MHz, it can be known from 525 MHz>500 MHZ that the detector 3 is located at the portion 31 of the detection area 21-ij toward the light sensing unit 511-ij in the +Z direction substantially perpendicular to the XY plane. And a near-velocity v is calculated from the frequency offset 依Büller effect of 525-500=+25 MHz; similarly, if the offset frequency is 475 MHz, it is known that the portion 31 is substantially perpendicular to the The -Z direction of the XY plane is away from the light sensing unit 511-ij, and a distant velocity v calculated by a frequency offset of 475-500 = -25 MHz, and the velocity v is the depth of field change.

Step 94: Using the processing unit 53 to binarize the identification amplitude value of each identification signal D _ij from the light sensing units 511-11~311-MN, and according to each identification signal D _ij The detection area 21-ij corresponding to the light sensing unit 511-ij receives a signal related to a plane (XY) image of the position of the detector 3 projected on the detection plane 2 ( As shown in Figure 7).

Here, the "binarization operation" refers to comparing the identification amplitude value with a threshold value, and when the identification amplitude value is greater than the threshold value, it is set to a first value, and if it is less than the threshold value, it is set to Another second value. In the preferred embodiment, each of the identification amplitude values is substantially positively correlated with the amount of reflection of the transmitted optical signal received by the light sensing unit 511, and the detector 3 is coupled to the light sensing array 51 or There is no other shielding between the transmission devices 4, so the identification amplitude value generated by the transmitted light signals blocked by the detecting object 3 and reflected to the light sensing units 511 is large, and is separated by other distances. The shield of the light sensing array 51 is blocked by a shield (not shown), and the value of the detected amplitude generated by the transmitted light signal reflected by the light sensing unit 511 is relatively small, and The first and second values give the planar image binarized as shown in FIG.

It should be noted that after the step 92 is completed, the step 94 can be directly performed, and then the step 93 is performed.

Referring to FIG. 2 and FIG. 7 , the linking device 6 is configured to generate a virtual image signal and is electrically connected to the receiving device 5 to receive the signal indicating the depth of field change and the signal of the planar image ( FIG. 7 ), and the virtual The image signal is used to present a virtual space 7 and a virtual object 8. The action of the virtual object 8 in the virtual space 7 is related to the depth of field change and the detector 3 is projected on the detection plane 2 (see FIG. 3). A change in the positional distribution on the ground and a change in the positional distribution of the detected object on the detection plane. For example, the linkage device 6 is applied to an interactive game. The detector 3 includes a block a of a plurality of locations 31. When the detection plane 2 is swung, the planar image corresponds to an image block A of the block a. With the displacement, the virtual portion 81 corresponding to the virtual object 8 is linked to the change in the XY direction of the virtual space 7; in addition, the depth of field changes of the portions 31 of the block a can be linked. The virtual portion 81 of the virtual object 8 changes in the Z direction.

Referring to FIG. 2 and FIG. 3, a preferred embodiment of the depth of field change detection system of the present invention is different from the preferred embodiment of the depth of field change detection and linkage system in that the depth of field change detection system includes a transmission device 4 and A receiving device 5. Further, the operation of the transporting device 4 and the receiving device 5 is as described above, and therefore will not be described again.

In summary, the above embodiment can estimate the number of the detectors 3 by loading the preset first frequency into the transmitted optical signal and according to the difference between the second frequency and the first frequency. The depth of field of each of the portions 31 varies, and the background light noise is filtered out by the filtering unit 54 without being disturbed by the background light noise, so that the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

Tx. . . Conveyor

Rx. . . Receiving device

11. . . Detector

12. . . Light source transmitter

13. . . lens

14. . . Laser speckle

15. . . lens

16. . . Image sensing array

161. . . Sensing unit

2. . . Detection plane

twenty one. . . Detection area

21-ij. . . Detection area

3. . . Detector

31. . . Part

a. . . Block

4. . . Conveyor

5. . . Receiving device

51. . . Light sensing array

511-11~511-65. . . Light sensing unit

52. . . Vertical scanning circuit

53. . . Horizontal scanning circuit

54. . . Filter unit

55. . . Processing unit

6. . . Linkage device

7. . . Virtual space

8. . . Virtual object

81. . . Virtual part

A. . . Image block

BW. . . Passband

f _2(max) . . . Second frequency

f _{2 (min)} . . . Second frequency

1 is a schematic diagram of a conventional depth of field identification system;

2 is a schematic diagram of a preferred embodiment of the depth of field change detection and linkage system of the present invention;

Figure 3 is a schematic view showing a detector in a side plane;

Figure 4 is a schematic illustration of a receiving device of the preferred embodiment;

Figure 5 is a schematic diagram of a spectrum of an identification signal;

6 is a flow chart illustrating a processing unit of the receiving device performing a detecting method; and

Figure 7 is a schematic illustration of a binarized planar image.

5. . . Receiving device

51. . . Light sensing array

511-11~511-65. . . Light sensing unit

52. . . Vertical scanning circuit

53. . . Horizontal scanning circuit

54. . . Filter unit

55. . . Processing unit

S _ij . . . Sense signal

Dij. . . Identification signal

Claims (10)

A depth of field detection system is configured to detect a detection object located in a detection plane, the detection plane includes a plurality of detection areas, and the detection object includes a plurality of parts that can reflect optical signals, and each Each of the parts is located in the corresponding detection area, and the system includes: a transmitting device for transmitting a transmitted light signal according to a first frequency to the detecting plane, and being static by the detecting object The transmitted optical signal reflected by the portion is maintained at the first frequency, and the transmitted optical signal reflected by the dynamic portion of the detected object is frequency-shifted to another second frequency; and a receiving device includes: The light sensing array has a plurality of light sensing units respectively corresponding to the detecting regions of the detecting plane, and each of the light sensing units is configured to receive the light signals from the corresponding detecting regions and generate a sense a signal filtering unit, electrically connected to the light sensing array, for receiving each sensing signal, and the filtering unit has a passband covering the first frequency and the second frequency, and a covering a background Frequency of optical noise And a processing unit electrically connected to the filtering unit for receiving each of the identification signals generated by the light sensing array and determining the spectrum of each of the identification signals a frequency of a maximum amplitude component, and a frequency of the maximum amplitude component is used as the second frequency; the processing unit uses a difference between the second frequency of each identification signal and the first frequency, and the identification signal The detection area corresponding to the light sensing unit is used to estimate a depth of field change of each portion of the detection object relative to the light sensing unit. The depth of field detection system according to claim 1, wherein the processing unit further uses the amplitude value of the maximum amplitude component of each identification signal as a recognized amplitude value, and binarizes the identification amplitude value. And calculating, according to the detection area corresponding to the light sensing unit from each of the identification signals, obtaining a signal related to a planar image of the position of the detection object projected on the detection plane. The depth of field detection system of claim 1, wherein the receiving device further comprises a vertical scanning circuit and a horizontal scanning circuit for outputting a vertical scanning signal and a horizontal scanning signal, respectively. The sensing array is further electrically connected to and controlled by the vertical scanning circuit and the horizontal scanning circuit, so that the sensing signals generated by the light sensing units are sequentially output, and the processing unit is further electrically connected to the a vertical scanning circuit and the horizontal scanning circuit, and receiving the vertical scanning signal and the horizontal scanning signal, and determining, according to the vertical scanning signal and the horizontal scanning signal, from which light sensing unit each of the identification signals is generated The filtering unit outputs. A receiving device is configured to detect a detecting object located in a detecting plane, where the detecting plane includes a plurality of detecting regions, where the detecting object includes a plurality of portions that can reflect optical signals, and each part has a respective The transmitting device is configured to transmit a transmitted light signal according to a first frequency to the detecting plane, where the receiving device comprises: a light sensing array having a plurality of corresponding respectively a light sensing unit of the detection area of the detection plane, each light sensing unit is configured to receive an optical signal from the corresponding detection area and generate a sensing signal; a filtering unit electrically connected to the The light sensing array is configured to receive each sensing signal, and the filtering unit has a passband covering the first frequency and the second frequency, and a stop band covering a frequency of the background optical noise, and outputting a filtered identification signal; and a processing unit electrically connected to the filtering unit for receiving each identification signal generated by the optical sensing array, and determining a maximum amplitude component in a spectrum of each identification signal Frequency, and the frequency of the maximum amplitude component is used as the second frequency; the processing unit uses a difference between the second frequency of each identification signal and the first frequency, and the light perception from the identification signal The detection area corresponding to the measurement unit estimates a depth of field change of each part of the detection object relative to the light sensing unit. The receiving device according to claim 4, wherein the processing unit further uses an amplitude value of a maximum amplitude component of each identification signal as a recognized amplitude value, and binarizes the identification amplitude value, and And obtaining, according to the detection area corresponding to the light sensing unit from each of the identification signals, a signal related to a planar image of a position distribution of the detection object on the detection plane. The receiving device according to claim 4, further comprising a vertical scanning circuit and a horizontal scanning circuit for outputting a vertical scanning signal and a horizontal scanning signal, wherein the light sensing array is also electrically connected and received The vertical scanning circuit and the horizontal scanning circuit are controlled such that the sensing signals generated by the light sensing units are sequentially output, and the processing unit is further electrically connected to the vertical scanning circuit and the horizontal scanning And aiming at the circuit, and receiving the vertical scanning signal and the horizontal scanning signal, and determining, according to the vertical scanning signal and the horizontal scanning signal, from which light sensing unit each of the identification signals is generated and outputted through the filtering unit. A depth of field change detection and linkage system is configured to detect a detection object located in a detection plane, the detection plane includes a plurality of detection areas, and the detection object includes a plurality of parts that can reflect optical signals. And each part is located in the corresponding detection area, the system includes: a transmitting device for transmitting a transmitted light signal according to a first frequency to the detecting plane; a receiving device, operatively The transmitting device is associated with: a light sensing array having a plurality of light sensing units respectively corresponding to the detecting regions of the detecting plane, each light sensing unit for receiving the corresponding detecting Detecting the optical signal of the area and generating a sensing signal; a filtering unit electrically connected to the light sensing array for receiving each sensing signal, and the filtering unit has a first frequency and the second frequency a passband, and a stop band covering a frequency of the background optical noise, and outputting a filtered identification signal; and a processing unit electrically connected to the filtering unit for receiving each generated by the light sensing array Identifying a signal, and determining a frequency of a maximum amplitude component in a spectrum of each of the identification signals, and using a frequency of the maximum amplitude component as the second frequency; the processing unit comparing the second frequency of each identification signal Estimating, according to a difference of the first frequency, and the detection area corresponding to the sensing unit from the sensing signal, estimating a depth of field change of each part of the detecting object relative to the light sensing unit, and And outputting a signal indicating the change of the depth of field; and a linkage device for generating a virtual image signal, and electrically connecting to the receiving device to receive the signal indicating the change of the depth of field, and the virtual image signal is used to present a virtual space And a virtual object, and the action of the virtual object in the virtual space is related to the depth of field change. According to the depth of field detection and linkage system described in claim 7, wherein the processing unit also uses the amplitude value of the maximum amplitude component of each identification signal as a recognized amplitude value, and performs the identification amplitude value The value is calculated, and according to the detection area corresponding to the light sensing unit from which each identification signal is derived, a signal related to a planar image of the position distribution of the detection object on the detection plane is obtained. According to the depth of field detection and linkage system of claim 8, wherein the linkage device also receives the signal of the planar image, and the action of the virtual object in the virtual space is related to the detection object projection. A change in the position distribution on the detection plane. The depth of field detection and linkage system of claim 7, wherein the receiving device further comprises a vertical scanning circuit and a horizontal scanning circuit for outputting a vertical scanning signal and a horizontal scanning signal, respectively. The light sensing array is also electrically connected and controlled by the vertical scanning circuit and the horizontal scanning circuit, so that the sensing signals generated by the light sensing units are sequentially output, and the processing unit is also electrically connected. The vertical scanning circuit and the horizontal scanning circuit receive the vertical scanning signal and the horizontal scanning signal, and determine, according to the vertical scanning signal and the horizontal scanning signal, from which light sensing unit each of the identification signals is generated. Then output through the filtering unit.