Distance sensor pixel array structure, distance sensor and working method

Abstract

The present invention discloses a distance sensor pixel array structure, a distance sensor and a working method. The distance sensor includes a transmitting end and a receiving end, and the receiving end includes a plurality of pixel units arranged in an array; some of the pixel units are irradiated by the light spots emitted by the transmitting end at normal power, and the irradiated pixel units are in an on state. Therefore, during operation, the on state of the transmitting end can be purposefully controlled, for example, only a part of the area is irradiated by the transmitting end, while other areas are not irradiated, so that the transmitting power can be greatly reduced, that is, the power consumption of TOF is greatly reduced, which promotes the popularization of TOF and indirectly promotes the popularization of AR and VR.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a distance sensor pixel array structure, a distance sensor and a working method. Background Art

[0002] As AR / VR technology is gradually implemented on mobile phones, 3D TOF (direct time of flight) distance sensors, as core chips, are gradually becoming standard features of mobile phones like 2D image sensors. However, the high power consumption has seriously affected its application on mobile phones, thus hindering the promotion of AR / VR technology.

[0003] The existing D TOF distance sensor consumes too much power, so the distance and usage time are limited when used on mobile phones, which affects the user experience. Face unlocking and payment can only be performed on the front camera of the phone, which does not require long-term operation. When used on the rear camera of a mobile phone or pad, such as AR and VR applications, it needs to be turned on for a long time, such as 1 hour of application, but the power consumption is too high, which can easily cause the phone to shut down. Therefore, AR and VR have not been popularized so far.

[0004] Therefore, only by significantly reducing the power consumption of D TOF can D TOF and AR and VR be popularized. Summary of the invention

[0005] The object of the present invention is to provide a distance sensor pixel array structure, a distance sensor and a working method to reduce the power consumption of the distance sensor.

[0006] In order to solve the above technical problems, according to a first aspect of the present invention, a distance sensor pixel array structure is provided, comprising:

[0007] A plurality of pixel units are arranged in an array, and some of the pixel units are turned on at the same time.

[0008] A plurality of pixel arrays, each pixel array comprises a plurality of elements, each element comprises at least one pixel unit, and some of the elements are turned on at the same time.

[0009] Optionally, multiple adjacent pixel units are turned on at the same time.

[0010] According to a second aspect of the present invention, there is provided a distance sensor, comprising a transmitting end and a receiving end, wherein the receiving end comprises a plurality of pixel units arranged in an array; some of the pixel units are illuminated by light spots emitted by the transmitting end at normal power, and the illuminated pixel units are in an on state.

[0011] Optionally, the light spot provided by the emitting end after passing through the collimator and the DOE includes a plurality of spots, and the spots provided by the emitting end each time correspond to different pixel units.

[0012] Optionally, the emitting end further provides a secondary light spot after passing through a collimator and DOE, and the energy of the secondary light spot is lower than the energy of the light spot.

[0013] Optionally, the emission end provides a light spot after passing through the diffusion sheet, and at least one area is illuminated at one time. The pixel unit of one area may be at least one pixel unit, a row of pixel units or a column of pixel units, or a plurality of pixel units.

[0014] According to a third aspect of the present invention, a working method of a distance sensor is provided, comprising: a transmitting end emits a light spot at normal power, which reaches a receiving end after being reflected by an object to be measured, wherein the receiving end comprises a plurality of pixel units arranged in an array, some of the pixel units are illuminated, and the illuminated pixel units are in an on state.

[0015] Optionally, the transmitting end also simultaneously emits a plurality of sub-light spots at a power lower than normal power, each sub-light spot irradiates a pixel unit and does not overlap with the light spot.

[0016] Optionally, the emitting end emits speckles, and each speckle illuminates a portion of at least one row of pixel units or a portion of at least one column of pixel units.

[0017] Optionally, the emitting end emits a light spot to illuminate pixel units in at least one area.

[0018] Compared with the prior art, in the technical solution of the present invention, the distance sensor includes a transmitting end and a receiving end, and the receiving end includes a plurality of pixel units arranged in an array; some of the pixel units are illuminated by the light spots emitted by the transmitting end at normal power, and the illuminated pixel units are in an on state. Therefore, when working, the on state of the transmitting end can be purposefully controlled, for example, only a part of the area is illuminated by the transmitting end, while other areas are not illuminated, so that the transmitting power can be greatly reduced, that is, the power consumption of TOF is greatly reduced, which promotes the popularization of TOF and indirectly promotes the popularization of AR and VR.

[0019] Furthermore, a partial area may be illuminated by a low-power light spot, which will not substantially reduce the instantaneous image resolution, but will greatly reduce power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of a D TOF distance sensor system;

[0021] Figure 2 Schematic diagram of the structure of D TOF pixel unit array;

[0022] Figure 3 It is a schematic diagram of the structure of a distance sensor pixel array in one embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of a transmitting end in one embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of a receiving end in one embodiment of the present invention;

[0025] Figure 6 Schematic diagram of the opening distribution of the receiving end pixel unit in one embodiment of the present invention Figure 1 ;

[0026] Figure 7 Schematic diagram of the states of the transmitting end and the receiving end at t1 in one embodiment of the present invention;

[0027] Figure 8 Schematic diagram of the opening distribution of the receiving end pixel unit in one embodiment of the present invention Figure 2 ;

[0028] Fig. 9 Schematic diagram of the states of the transmitting end and the receiving end at t3 in one embodiment of the present invention;

[0029] Fig.10 A schematic diagram of the opening distribution of multiple rows of pixel units at the receiving end in one embodiment of the present invention;

[0030] Fig.11 A schematic diagram of the opening distribution of multi-region pixel units at a receiving end in one embodiment of the present invention;

[0031] Fig.12 FIG. 4 is a schematic diagram of a working method of a distance sensor in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be described in more detail with reference to the schematic diagrams of the distance sensor pixel array structure, the distance sensor and the working method of the present invention, wherein the preferred embodiments of the present invention are shown, and it should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as being widely known to those skilled in the art and not as a limitation of the present invention.

[0033] The present invention is described in more detail in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are in very simplified form and in non-precise proportions, and are only used to facilitate and clearly assist in illustrating the purpose of the embodiments of the present invention.

[0034] After research, the inventor found that for a common D TOF distance sensor system, the transmitter is a light source and the receiver is an array, such as a VGA (640*480) array, so the resolution is 640*480. When working, the transmitter illuminates the array area of ​​all 640*480 pixels of the receiver. Therefore, the power consumption is very large.

[0035] Therefore, the inventors broke through the limitations of the existing technology and adopted regional transmission. When the receiving end receives a certain area, the transmitting end transmits to that area, and the corresponding transmitting end of the non-working pixel area is turned off, thereby avoiding the waste of transmission power consumption.

[0036] Example 1

[0037] Embodiment 1 of the present invention provides a distance sensor pixel array structure. The implementation details of this embodiment are described in detail below in conjunction with the accompanying drawings. The following content is only for the convenience of understanding the implementation details provided and is not necessary for the implementation of this solution. Please refer to Figure 3 , this embodiment includes:

[0038] A plurality of pixel units are arranged in an array, and some of the pixel units are turned on at the same time.

[0039] In this embodiment, adjacent i×j pixel units form a group 10 , and the distance sensor pixel array structure includes a plurality of groups 10 .

[0040] For example, each group 10 is a combination of 2×2 pixel units.

[0041] Typically, each group may be identical.

[0042] In addition, each group may also be in other forms, such as 2×3, 3×3, etc. In the present embodiment, each group does not need to be too complicated.

[0043] Taking a simple 2×2 as an example, in each group 10 , the pixel unit 101 , the pixel unit 102 , the pixel unit 103 , and the pixel unit 104 are turned on in the order of sequentially.

[0044] In addition, for example, multiple adjacent pixel units may be turned on at the same time.

[0045] Example 2

[0046] Embodiment 2 of the present invention provides a distance sensor, which may be further optimized or improved on the basis of embodiment 1. The implementation details of this embodiment are described in detail below. The following content is only for the convenience of understanding the implementation details, and is not necessary for implementing this solution. This embodiment includes:

[0047] A transmitting end and a receiving end, wherein the receiving end includes a plurality of pixel units arranged in an array; some of the pixel units are illuminated by the light spots emitted by the transmitting end at normal power, and the illuminated pixel units are in an on state.

[0048] Therefore, in the embodiment of the present invention, only the elements in the turned-on state will be irradiated, so that the utilization rate of the transmitting end is maximized, thereby avoiding the waste of transmitting power consumption.

[0049] Example 3

[0050] Embodiment 3 of the present invention is a distance sensor, which can be further optimized or improved on the basis of embodiment 2. The implementation details of this embodiment are described in detail below in conjunction with the accompanying drawings. The following content is only for the convenience of understanding the implementation details, and is not necessary for the implementation of this solution. Please refer to Figure 4 and Figure 5 , this embodiment includes:

[0051] For example, the transmitting end can be divided into a plurality of light-emitting areas, such as Figure 4 The schematic diagram shows the light-emitting area 1, the light-emitting area 2, the light-emitting area 3 and the light-emitting area 4. Different light-emitting areas can emit light at different time periods. The receiving end can be divided into multiple receiving areas, such as Figure 5 The receiving area 1, receiving area 2, receiving area 3 and receiving area 4 are schematically shown, and different receiving areas can be turned on at different time periods. For example, when the light-emitting area 1 emits light, the corresponding receiving area 1 is turned on, and other light-emitting areas and receiving areas are turned off, thereby improving the utilization rate of the transmitting end.

[0052] Example 4

[0053] Embodiment 4 of the present invention is a distance sensor, which can be further optimized or improved on the basis of embodiment 2 or embodiment 3. The implementation details of this embodiment are described in detail below in conjunction with the accompanying drawings. The following content is only for the convenience of understanding the implementation details, and is not necessary for the implementation of this solution. Please refer to Figure 6 and Figure 7 , this embodiment includes:

[0054] The transmitting end includes a vertical cavity surface emitting laser (Vertical Cavity Surface Emitting Laser, VCSEL), and the light spot provided after passing through a collimator and DOE (Diffractive Optical Elements) includes a plurality of speckles, and the speckle provided by the transmitting end each time corresponds to a different pixel unit.

[0055] like Figure 6As shown, the receiving end includes multiple groups 10, and each group of four pixel units 101-104 in the upper, lower, left and right directions works at different times. At this time, the D TOF pixel array with m*n resolution is actually composed of m / 2*n / 2 groups. When the global exposure is performed, the spad (single photon avalanche diode) at the corresponding position is turned on in four time periods of t1, t2, t3, and t4. Therefore, it is equivalent to being divided into 4 staggered areas for time-sharing operation as a whole.

[0056] For example, Figure 7 It is shown that at t1, only the emitting end of the corresponding area works, for example, a light spot is provided, specifically, a plurality of specks 201 are provided, each speckle 201 corresponds to irradiating pixel unit 101, while pixel unit 102, pixel unit 103 and pixel unit 104 are not irradiated.

[0057] Example 5

[0058] Embodiment 5 of the present invention is a distance sensor, which can be further optimized or improved on the basis of embodiment 4. The implementation details of this embodiment are described in detail below in conjunction with the accompanying drawings. The following content is only for the convenience of understanding the implementation details, and is not necessary for the implementation of this solution. Please refer to Figure 8 and Fig. 9 , this embodiment includes:

[0059] Each group 10 ′ includes a plurality of pixel units.

[0060] For example, there are four pixel units 101 ′, 102 ′, 103 ′ and 104 ′ on the top, bottom, left and right sides, which can work in four time periods t1 , t2 , t3 and t4 , respectively.

[0061] Accordingly, please refer to Fig. 9 , indicating that at t3, only the emitting end of the corresponding area works, for example, a light spot is provided, specifically, a plurality of specks 202 are provided, more specifically, each speckle 202 is a group of four, each speckle 202 corresponds to the irradiated pixel unit 103', while the pixel unit 101', the pixel unit 102', and the pixel unit 104' are not irradiated.

[0062] Example 6

[0063] Embodiment 6 of the present invention is a distance sensor, which can be further optimized or improved on the basis of embodiment 4 or embodiment 5. The implementation details of this embodiment are described in detail below. The following content is only for the convenience of understanding the implementation details, and is not necessary for the implementation of this solution. This embodiment includes:

[0064] The emitting end further provides a secondary light spot after passing through a collimating lens and DOE, and the energy of the secondary light spot is lower than the energy of the light spot.

[0065] For example, the transmitting end may provide the secondary light spot with a power less than or equal to 10% of the normal power.

[0066] In this embodiment, a partial area may be illuminated by a low-power light spot, which will not substantially reduce the instantaneous image resolution, but will greatly reduce power consumption.

[0067] Example 7

[0068] Embodiment 7 of the present invention is a distance sensor, which can be further optimized or improved on the basis of Embodiment 2 or Embodiment 3. The implementation details of this embodiment are described in detail below in conjunction with the accompanying drawings. The following content is only for the convenience of understanding the implementation details, and is not necessary for the implementation of this solution. Please refer to Fig.10 , this embodiment includes:

[0069] The emission end provides a light spot after passing through a diffuser, and at least illuminates pixel units in one area at one time.

[0070] The pixel units of the one area may be at least one pixel unit, a row of pixel units or a column of pixel units, or a plurality of pixel units, etc.

[0071] For example, it may be common to illuminate at least one row or column with one shot.

[0072] Specifically, the light spot in this embodiment may be in the form of a surface light source, such as a long strip.

[0073] like Fig.10 Seven rows of pixel units are illustrated from top to bottom, and each row works at Time 1, Time 2, Time 3, Time 4, Time 5, Time 6 and Time 7, respectively. Accordingly, the light spot irradiates the pixel units of the corresponding row in the corresponding time period.

[0074] It is understandable that, for example, it can also be in the form of from bottom to top, or from the middle to both sides, or from both sides to the middle, etc.

[0075] in addition, Fig.10 The column form is illustrated, and the row form is the same as the column form, and this application will not describe it in detail.

[0076] Example 8

[0077] Embodiment 8 of the present invention is a distance sensor, which can be further optimized or improved on the basis of embodiment 7. The implementation details of this embodiment are described in detail below in conjunction with the accompanying drawings. The following content is only for the convenience of understanding the implementation details, and is not necessary for the implementation of this solution. Please refer to Fig.11 The difference between this embodiment and embodiment 7 is that at least one area is irradiated in one emission.

[0078] like Fig.11 In the figure, six regions are illustrated. The six regions may be a row, a column, a part of a row, a part of a column, or an i×j array in an m×n pixel unit array, where i<m, j<n.

[0079] Fig.11 The six areas work at Time 1, Time 2, Time 3, Time 4, Time 5 and Time 6 respectively, and accordingly, the light spot irradiates the pixel units of the corresponding areas in the corresponding time periods.

[0080] in Fig.11 The illustrated order is from top to bottom and from left to right. It is understandable that other orders are also possible, such as from bottom to top and from right to left, for example, multiple non-adjacent areas work simultaneously, etc.

[0081] Example 9

[0082] Embodiment 9 of the present invention provides a working method of a distance sensor. The implementation details of this embodiment are described in detail below in conjunction with the accompanying drawings. The following content is only for the convenience of understanding the implementation details provided and is not necessary for implementing this solution. This embodiment can be based on the structure of embodiments 1-8, and may not be limited to the structure provided by the present invention. The method of the embodiment of the present invention includes:

[0083] The transmitting end emits a light spot at normal power, which reaches the receiving end after being reflected by the object to be measured. The receiving end includes a plurality of pixel units arranged in an array, some of which are illuminated, and the illuminated pixel units are in an on state.

[0084] like Fig.12 As shown, the light spots emitted by different light-emitting areas reach the corresponding receiving areas after passing through the measured object, so that the light-emitting areas can be turned on or off according to different needs.

[0085] Please combine Figure 6 and Fig.12 , for example, for a 2*2 group 10. The specific working sequence is that when the entire sensor is working, at time t1, the light spot is emitted by the light-emitting area 1 to illuminate only the upper left pixel unit 101 of each group 10, so that the receiving end receives a 3D image 1;

[0086] At time T2, the light spot is emitted by the light emitting area 2 to illuminate only the pixel unit 102 at the upper right of each group 10, so that the receiving end receives a 3D image 2;

[0087] At time T3, the light spot is emitted by the light emitting area 3 to illuminate only the pixel unit 103 at the lower left of each group 10, so that the receiving end receives a 3D image 3;

[0088] At time T4, the light spot is emitted by the light emitting area 4, illuminating only the pixel unit 104 at the lower right of each group 10, so that the receiving end receives a 3D image 4;

[0089] Finally, images 1-4 are stitched together into one image to get a complete m*n resolution distance map.

[0090] In addition, the emitting end emits speckles, each speckle irradiating a portion of at least one row of pixel units or a portion of at least one column of pixel units.

[0091] In addition, the transmitting end may also emit a light spot at normal power to illuminate pixel units in at least one area. The pixel units in the area may be at least one pixel unit, a row of pixel units or a column of pixel units, or a plurality of pixel units.

[0092] The illumination of a row, a column or an area can be performed sequentially, for example, from left to right, from top to bottom, etc.; it can also be performed in a symmetrical manner, from the middle to both sides, or from both sides to the middle, etc.

[0093] Example 10

[0094] This embodiment can be further optimized or improved on the basis of embodiment 9. The main feature of embodiment 10 is that the transmitting end also emits multiple secondary light spots at a power lower than the normal power at the same time, each secondary light spot illuminates a pixel unit and does not overlap with the light spot.

[0095] Specifically, the power lower than the normal power is less than or equal to 10% of the normal power, such as 1%, 5%, etc.

[0096] As a result, the instantaneous image resolution is not substantially reduced, but the power consumption is greatly reduced.

[0097] Embodiment 11

[0098] This embodiment provides an application of a distance sensor in AR / VR, which may include the structure described in any one of Embodiments 1-8.

[0099] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A distance sensor, characterized in that: It includes a transmitting end and a receiving end, wherein the receiving end includes a plurality of pixel units arranged in an array, and some of the pixel units are turned on at the same time; Adjacent i×j pixel units form a group, the receiving end includes multiple groups, the pixel units in each group work at different times, and all pixel units in each group are turned on in sequence; Some of the pixel units are illuminated by the light spots emitted by the emitting end at normal power, and the illuminated pixel units are in an on state; The light spot provided by the emitting end after passing through the collimator and the DOE includes a plurality of spots, and the spots provided by the emitting end each time correspond to different pixel units.

2. The distance sensor according to claim 1, characterized in that Multiple adjacent pixel units are turned on at the same time.

3. The distance sensor according to claim 1, characterized in that The emitting end further provides a secondary light spot after passing through a collimating lens and DOE, and the energy of the secondary light spot is lower than the energy of the light spot.

4. The distance sensor according to claim 3, characterized in that The emission end provides a light spot after passing through the diffusion sheet, and at least illuminates the pixel units in one area at one time.

5. A method for operating a distance sensor, characterized in that: include: The transmitting end emits a light spot at normal power, which reaches the receiving end after being reflected by the object to be measured. The receiving end includes a plurality of pixel units arranged in an array, some of which are illuminated, and the illuminated pixel units are in an on state; Adjacent i×j pixel units form a group, the receiving end includes multiple groups, the pixel units in each group work at different times, and all pixel units in each group are turned on in sequence; The light spot provided by the emitting end after passing through the collimator and the DOE includes a plurality of spots, and the spots provided by the emitting end each time correspond to different pixel units.

6. The operating method of the distance sensor according to claim 5, characterized in that: The transmitting end also simultaneously transmits a plurality of sub-light spots at a power lower than normal, each sub-light spot irradiates a pixel unit and does not overlap with the light spot.

7. The operating method of the distance sensor according to claim 5, characterized in that: The emitting end emits speckles, each speckle irradiating a portion of at least one row of pixel units or a portion of at least one column of pixel units.

8. The operating method of the distance sensor according to claim 5, characterized in that: The emitting end emits a light spot to illuminate pixel units in at least one area.

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