TW202122822A - A time-of-flight sensing system and light emitter thereof - Google Patents

Abstract

The invention relates to a time-of-flight polarized light sensing system. The time-of-flight polarized light sensing system including a light transmitter, a light sensor, and a signal processing circuit. First, the light transmitter emits a first pulsed light having a first polarization direction and a second pulsed light having a second polarization direction. And then, the light sensor detects a pulsed light reflected by a target, so as to output the first sensing signal through the first sub-pixel repeating unit and output the second sensing signal through the second sub-pixel repeating unit. Then, the signal processing circuit determines the pulse signal according to the first sensing signal and the second sensing signal, and eliminates a background noise signal. Finally, the depth information of the target is determined by the pulsed light and the pulsed signals, thereby effectively eliminating the effect of background noise caused by natural light in the environment. The invention achieves the goals of accuracy, speed and saving labor cost, etc.

Description

Time-of-flight polarization sensing system and its light emitter

The present invention relates to a time-of-flight polarization sensing system, in particular to a time-of-flight polarization sensing system using the characteristics of polarized light.

Time-of-Fight (Time-of-Fight) is an active 3D scanning technology that has been frequently used in recent years. The main reasons are the large measurable range, high resolution and low software complexity, which is conducive to market expansion and technology Development.

The sensing technology of the time-of-flight method is to add another sensor element that can measure the depth information on the traditional image sensor. This element calculates the depth information by sensing the time change of light reflection and reception.

At present, the conventional sensing technology of the time-of-flight ranging method generally uses two wavelengths of 850nm and 940nm infrared light (Infrared Radiation, IR) as the emitted light, the reason is that this wavelength is less interfered by ambient light , In this way can get clearer in-depth information. However, the light of these two wavelength bands still exists in the general environment, so how to reduce the interference of natural light in the environment again is one of the problems that should be solved by the developers.

The object of the present invention is to provide a time-of-flight polarization sensing system and method thereof. The time-of-flight polarization sensing system uses a polarized laser light source to perform the calculation of the ToF sensing technology, so that the polarization sensing system can achieve improved accuracy. It can reduce the interference of ambient light and improve the signal-to-noise ratio.

To achieve the above objective, the present invention provides a time-of-flight polarization sensing system, including: a light emitter that emits a first pulsed light with a first polarization direction and a second pulsed light with a second polarization direction; The sensor is used to sense the reflected first pulse light and the second pulse light; and a signal processing circuit (Signal Processor) is coupled to the light emitter and the light sensor.

The light emitter according to the present invention may be composed of a light emitting array, a first direction polarizer and a second direction polarizer. The light emitting array can be, for example, a pulsed light emitter or a laser diode, and the first direction polarizer and the second direction polarizer can be birefringent crystals (Briefringence Crystal Materials) or metal gratings. Metal Grating).

Preferably, in an embodiment of the present invention, the light emitting array may use a surface-emitting laser (VCSEL) to reduce the directivity to achieve the purpose of increasing the projection coverage range.

Preferably, when the first direction polarizer and the second direction polarizer are metal gratings, the periodic interval between the metal lines and the metal lines in the metal grating can be less than half the wavelength of the light emitted by the light emitting array one.

The light emitter according to the present invention may further include a light diffuser, which converts any parallel input incident light into uniform intensity and ideal spot shape output, and the light diffuser may be arranged above the light emitting array.

Preferably, in an embodiment of the present invention, the first direction polarizer and the second direction polarizer are arranged on the light diffuser, and the light diffuser is arranged on the light emitting array.

Preferably, in an embodiment of the present invention, the first direction polarizer and the second direction polarizer are arranged in the light diffuser, and the light diffuser is arranged on the light emitting array.

The light sensor according to the present invention is used for sensing reflected pulsed light to output a first sensing signal through the first sub-pixel repeating unit and output a second sensing signal to the signal through the second sub-pixel repeating unit Processing circuit. Wherein, the first sub-pixel repeating unit includes a plurality of color sub-pixel units and a first pulsed light sensing unit with a first polarization direction; the second sub-pixel repeating unit includes a plurality of color sub-pixel units and has a second polarization direction. The second pulsed light sensing unit in the polarization direction.

According to the signal processing circuit of the present invention, the pulse signal is determined according to the first sensing signal and the second sensing signal. The signal processing circuit calculates the depth information of the sensing target according to the pulsed light and the pulse signal, and the signal processing circuit can be a digital circuit or an analog circuit.

Another object of the present invention is to provide a method of time-of-flight polarization sensing, including the following steps: an emission step, using a light emitter to emit a first pulsed light with a first polarization direction and a second polarization The second pulsed light in the direction of chemical conversion; a sensing step, the pulsed light reflected by the sensing target is sensed by the light sensor, and the first sensing signal is output by the first sub-pixel repeating unit and by the second sub-pixel repeating unit. The pixel repeating unit outputs the second sensing signal; a calibration step, the signal processing circuit determines the pulse signal according to the first sensing signal and the second sensing signal, and eliminates the signal of the background noise; a calculation step, based on the pulsed light and the pulse Signal to determine the depth information of the sensing target.

The time-of-flight polarization sensing system and method provided by the present invention mainly use the time-of-flight polarization sensing system of the present invention, combined with the time-of-flight polarization sensing method, so that the user can use the high signal-to-noise ratio to deviate The polarized laser light source effectively eliminates the influence of background noise caused by natural light in the environment and executes the calculation of ToF sensing technology to achieve accuracy, speed, practicality and save labor costs.

In order to enable those skilled in the art to understand the purpose, features, and effects of the present invention, the following specific embodiments and accompanying drawings are used to explain the present invention in detail as follows.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Throughout the specification, the same reference numerals basically denote the same elements. In the following description, when it is determined that a detailed description of a related conventional technology or configuration will cause confusion in the technical content disclosed in the present invention, the detailed description thereof will be omitted. When describing several embodiments, the introduction part in this specification typically describes the same elements, and may be omitted in other embodiments.

Terms including ordinal numbers, such as first and second, can be used to describe various elements, but these elements are not limited by the terms. These terms are only used to distinguish one element from another.

FIG. 1 is a schematic diagram of the time-of-flight polarization sensing system of the present invention. The time-of-flight distance measuring sensor 100 shown in FIG. 1 includes: a signal processing circuit 110, a light transmitter 120 and a light sensor 130. Wherein, the signal processing circuit 110 is coupled to the light transmitter 120 and the light sensor 130, which can be a digital circuit or an analog circuit; the light transmitter 120 can be, for example, a pulsed light transmitter or a laser diode, which is used to A light pulse of infrared light is emitted; the light sensor 130 may be, for example, a complementary metal oxide semiconductor image sensor (CMOS Image Sensor, CIS).

FIG. 2 is a flowchart illustrating the steps of the time-of-flight polarization sensing method performed by the time-of-flight polarization sensing system of the present invention. First, in the emission step S210, the light emitter 120 emits pulsed light with a polarization direction, and then the process proceeds to step S220.

In the sensing step S220, the reflected pulsed light is sensed by the photo sensor 130, so that the first sub-pixel repeating unit outputs a first sensing signal and the second sub-pixel repeating unit outputs a second sensing signal. Measure the signal, and go to step S230.

In the calibration step S230, the signal processing circuit 110 determines the pulse signal according to the first sensing signal and the second sensing signal, and eliminates the signal of the background noise, and proceeds to step S240.

In the calculation step S240, the signal processing circuit 110 determines the depth information of the sensing target according to the pulsed light and the pulsed signal.

In order to further understand the structural features, application methods, and expected effects of the present invention, the preferred embodiments of the present invention will be described below, and it is believed that a deeper and more detailed understanding of the present invention can be obtained from this.

FIG. 3 is a schematic diagram of an active transmission line performance diagnosis system according to an embodiment of the present invention. The time-of-flight distance measurement sensor 100 includes a signal processing circuit 110, a light transmitter 120, a light sensor 130 and a sensing target 200. Wherein, the signal processing circuit 110 is coupled to the light transmitter 120 and the light sensor 130, which can be a digital circuit or an analog circuit; the light transmitter 120 can be, for example, a pulsed light transmitter or a laser diode, which is used to A light pulse of infrared light is emitted; and the light sensor 130 may be, for example, a complementary metal oxide semiconductor image sensor.

In an embodiment of the present invention, as shown in FIG. 4A, the light emitter 121 may be composed of a light emitting array 410, a first direction polarizer 420 and a second direction polarizer 430. The light emitting array 410 may be, for example, a pulsed light emitter or a laser diode, and the first direction polarizer 420 and the second direction polarizer 430 may be birefringent crystals or metal gratings, but are not limited thereto.

Wherein, when the first direction polarizer 420 and the second direction polarizer 430 are metal gratings, the condition for effective polarization is that the periodic spacing between the metal lines in the metal grating is smaller than that emitted by the light emitting array 410 Half of the wavelength of the light, for example, when the periodic interval between the metal lines and the metal lines in the metal grating is 500 nm, only the infrared light region with a wavelength above 800 nm can be polarized. However, when the periodic interval between the metal lines and the metal lines in the metal grating is 200 nm, the range of polarization that can be polarized is from the visible light region above 380 nm to the infrared light region.

Specifically, as shown in FIG. 4A, the light emitting array 410 may adopt a surface-emitting laser (VCSEL) to reduce the directivity to achieve the purpose of increasing the projection coverage range.

Specifically, after the light emitting array 410 emits pulsed light through the polarizer 420 in the first direction, a first pulsed light having the first polarization direction is formed, and the pulsed light emitted by the light emitting array 410 passes through the polarizer 430 in the second direction. , Forming a second pulsed light having the second polarization direction.

It should be further explained that, according to the light emitter 121 of an embodiment of the present invention, as shown in FIG. 4A, since the light emitting array 410 adopts a surface-emitting laser, the diameter of each individual light-emitting source is about 0.015 mm. If a metal grating is used as the first direction polarizer 420 and the second direction polarizer 430, it will be difficult to implement in the manufacturing process. Therefore, according to the light emitter 121 of an embodiment of the present invention, the first direction polarizer 420 and the second direction polarizer 430 are birefringent crystals.

Although FIG. 4A shows an embodiment of the light emitter 120, the present invention is not limited to this. The light emitter 120 may further include a light diffuser 440, which is disposed above the light emitter 120, as shown in FIG. 4B Show. However, in the embodiment of the light emitter 122 shown in FIG. 4B, when the light passes through the first-direction polarizer 420 and the second-direction polarizer 430, the noise generated after being polarized will pass through the light diffuser 440 synchronously. Amplification causes the noise ratio of the pulsed light with the polarization direction to drop.

Therefore, as shown in FIG. 4C, according to the light emitter 123 of another embodiment of the present invention, the light diffuser 440 may be disposed under the first direction polarizer 420 and the second direction polarizer 430, and the light diffuser 440 It is arranged above the light emitting array 410. In this way, it is possible to effectively reduce the noise generated when the light passes through the polarization of the polarizer 420 in the first direction and the polarizer 430 in the second direction, thereby increasing the noise ratio of the pulsed light in the polarization direction, so as to obtain better comparison. Good resolution and sounding accuracy, but the present invention is not limited to this.

Further, as shown in FIG. 4D, according to the light emitter 124 of another embodiment of the present invention, the first direction polarizer 420' and the second direction polarizer 430' are arranged in the light diffuser 440', and the light The diffuser 440 ′ is disposed on the light emitting array 410. The reason is that when the light emitting array 410 adopts a surface-emitting laser, the diameter of each individual light emitting source is about 0.015 mm, and when it is necessary to set the first direction polarizer 420' and the second direction polarizer 430' and the light source respectively. When the diffuser 440 is used, it is difficult to realize in the manufacturing process. Therefore, by combining the first direction polarizer 420', the second direction polarizer 430', and the light diffuser 440 to form the light diffuser 440', the light emitter 124 according to another embodiment of the present invention remains With better resolution and sounding accuracy, it effectively reduces manufacturing time and labor costs. It should be further explained that when the light diffuser 440' is used, the first direction polarizer 420' and the second direction polarizer 430' will no longer be limited to the use of birefringent crystals, but metal gratings can be used as The first-direction polarizer 420' and the second-direction polarizer 430' further effectively reduce the manufacturing cost and improve the process yield.

Specifically, as shown in FIG. 5A and FIG. 5B, the photo sensor 130 may include: a first sub-pixel repeating unit 531 and a second sub-pixel repeating unit 532. The first sub-pixel repeating unit 531 includes a plurality of color sub-pixel units and a first pulsed light sensing unit IR1 having a first polarization direction; the second sub-pixel repeating unit 532 includes a plurality of color sub-pixel units and a second The second pulsed light sensing unit IR2 in the polarization direction, therefore, the light sensor 130 according to an embodiment of the present invention can be used to obtain color image information, infrared light image information, and depth information.

Specifically, in an embodiment of the present invention, the light transmitter 120 may emit pulsed light with a vertical polarization direction or pulsed light with a horizontal polarization direction to the sensing target 200.

Wherein, the first pulsed light sensing unit IR1 may have a first polarization direction, and the first polarization direction may be vertical polarization, and the second pulsed light sensing unit IR2 may have a second polarization direction And the second polarization direction may be horizontal polarization. For example, the light transmitter 120 may emit pulsed light with a vertical polarization direction to the sensing target 200, and the sensing target 200 reflects the pulsed light with the vertical polarization direction to be located in the photo sensor 130, with The first pulsed light sensing unit IR1 with a vertical polarization direction and the second pulsed light sensing unit IR2 with a horizontal polarization direction.

（1）Specifically, referring to FIG. 3, the signal processing circuit 110 can convert the optical path length of the pulsed light according to the following formula (1) according to the time from when the pulsed light is emitted to sensing the reflected pulsed light, and according to the flight of the present invention The time range sensor 100 can distinguish between the polarized pulsed light reflected by the sensing target 200 and the background noise corresponding to the ambient light according to the sensing results of different polarizations, and can be applied to various Signal strength and wavelength of pulsed light.

(1)

Where c is the speed of light, d is the distance between the time-of-flight range sensor 100 and the sensing target 200, θ is the angle between the time-of-flight range sensor 100 and the sensing target 200, and T is the time. However, when the distance d between the time-of-flight ranging sensor 100 and the sensing target 200 is large, the value of θ can be neglected, resulting in the value of cos(θ) being 1, resulting in one-half of the optical path length being The distance between the time-of-flight range sensor 100 and the sensing target 200.

Referring to FIGS. 3 to 5B, after the first pulsed light sensing unit IR1 of the light sensor 130 receives the pulsed light having a vertical polarization direction after being reflected by the sensing target 200, it can be adjusted according to the vertical polarization direction. The pulsed light and the corresponding ambient light output the first sensing signal. The first sensing signal includes a pulse signal corresponding to the pulsed light and a first background noise signal corresponding to the portion of the overall background noise of the ambient light having a vertical polarization direction, and the second pulse of the photo sensor 130 After the light sensing unit IR2 receives the pulsed light with a vertical polarization direction after being reflected by the sensing target 200, it can output a second sensing signal according to the corresponding ambient light, and the second sensing signal contains a signal corresponding to the ambient light. The remaining part of the overall background noise has a second background noise signal in the horizontal polarization direction.

It must be further explained that since the polarization direction of the second pulsed light sensing unit IR2 is different from that of the pulsed light, the second sensing signal does not include the pulsed signal corresponding to the pulsed light.

Specifically, since the signal strength of the first background noise signal is the same as or similar to the signal strength of the second background noise signal, the signal processing circuit 110 according to an embodiment of the present invention can be based on different pixel units with different polarizations. The obtained first sensing signal and the second sensing signal are subjected to a calculation operation of signal intensity subtraction, and the signal waveform of the pulse signal without background noise can be obtained. In other words, the signal processing circuit 110 of this embodiment can accurately calculate the time-of-flight distance measurement based on the time difference between the polarized pulsed light emitted by the light transmitter 120 and the pulse signal sensed by the light sensor 130. The distance between the sensor 100 and the sensing target 200.

Referring to FIG. 6 in conjunction with FIG. 2 and FIG. 3, it is used to illustrate the flow steps of the time-of-flight polarization sensing system in FIG. 3 to perform its method. The following steps can be performed.

First, in the emission step S210, the signal processing circuit 110 sends out a voltage signal Sa under user control, and the light emitter 120 emits pulsed light with a vertical polarization direction according to the voltage signal Sa, wherein the voltage signal Sa includes pulses Signal P.

Next, proceed to the sensing step S220. As shown in FIG. 6, while the signal processing circuit 110 is controlled by the user to send out the voltage signal Sa, the first pulsed light sensing unit IR1 with the vertical polarization direction and the first pulse light sensing unit IR1 with the horizontal polarization The second pulsed light sensing unit IR2 in the polarization direction is activated and continues to sense, and after the light emitter 120 emits pulsed light with a vertical polarization direction to the sensing target 200, the sensing target 200 reflects the vertical polarization When the pulsed light in the chemical direction reaches the first pulsed light sensing unit IR1 and the second pulsed light sensing unit IR2 in the photo sensor 130, the first pulsed light sensing unit IR1 outputs the voltage signal Sp and the second pulsed light The sensing unit IR2 outputs a voltage signal Sb.

Furthermore, proceed to the calibration step S230. As shown in FIG. 6, since the polarization direction of the first pulsed light sensing unit IR1 is the same as that of the pulsed light, the voltage signal Sp output by the first pulsed light sensing unit IR1 may contain a voltage signal corresponding to The ambient light background noise signal BN' and pulse signal P'. In this embodiment, since the polarization direction of the second pulsed light sensing unit IR2 is different from that of the pulsed light, the voltage signal Sp output by the second pulsed light sensing unit IR2 only contains the background noise signal corresponding to the ambient light BN. In this embodiment, the background noise signals BN and BN' under the same ambient light have the same or similar signal strength. Therefore, the signal processing circuit 110 can obtain the output by comparing the voltage signals Sp and Sb and performing a subtraction operation. The voltage signal Sr, the voltage signal Sr only has the pulse signal P′ and eliminates the background noise signal.

Finally, entering the calculation step S240, the signal processing circuit 110 can calculate the time-of-flight ranging sensing based on the time difference between the generation time of the pulse signal P'of the voltage signal Sr and the generation time of the pulsed light emitted by the light transmitter 120. The distance between the sensor 100 and the sensing target 200.

It should be further explained that, according to the embodiment of the present invention, the background noise signal caused by natural light in the environment can be eliminated by simple subtraction operation without complicated software operation, and the signal processing circuit 110 can be effectively reduced. The processing time reduces the software complexity, and even when the signal strength of the background noise signals BN and BN' is greater than the pulse signal P and P', the signal processing circuit 110 can still compare the voltage signals Sp and Sb and perform phase The subtraction operation eliminates the background noise signal, effectively performs the operation and performs distance sensing to obtain accurate distance sensing results.

FIG. 7 is a signal timing diagram of a pulse signal according to an embodiment of the invention. 3 and 6, when the signal processing circuit 110 performs a subtraction operation to obtain a pulse signal corresponding to the pulsed light sensed by the light sensor 130 without background noise, the signal processing circuit 110 can directly fly Time (Direct Time-of-Flight, D-ToF) ranging operation to calculate the pulse light transmission time to calculate the depth information of the sensing target 200, where the depth information of the sensing target 200 refers to the time-of-flight ranging sensor The distance between the sensor 100 and the sensing target 200. Specifically, the signal processing circuit 110 calculates the sensing target 200 according to the time difference T1 between the pulsed light (pulse signal P1) emitted by the light transmitter 120 and the reflected pulsed light (pulse signal P1') sensed by the light sensor 130 In-depth information. The time difference T1 may be, for example, the length of time between the rising edge of the pulse signal P1 and the rising edge of the pulse signal P1', that is, in this embodiment, the signal processing circuit 110 may multiply the time difference T1 by the speed of light (c) and then Divide by 2 to get distance information.

It should be further explained that, according to the embodiment of the present invention, the sensing technology using the time-of-flight ranging method will no longer be limited to using only two wavelengths of 850nm and 940nm infrared light as emitted light, but can be used Various wavelengths and even the wavelength range of visible light are used as emitted light, which effectively enhances the scope of application and practicability of the present invention.

Therefore, the present invention has the following implementation effects and technical effects:

First, in the present invention, by arranging the light diffuser 440 between the first direction polarizer 420 and the second direction polarizer 430 and the light emitting array 410, it can effectively reduce when light passes through the first direction polarizer 420 and the second direction. The noise generated by the polarization of the polarizer 430 further increases the noise ratio of the pulsed light in the polarization direction to obtain better resolution and depth sounding accuracy.

Second, the present invention further transmits the first direction polarizer 420 and the second direction polarizer 430 in the light diffuser 440', and the light diffuser 440' is arranged on the light emitting array 410. In this way, while maintaining better resolution and sounding accuracy, the production time and labor costs are effectively reduced.

Third, using the in-flight polarization sensing system of the present invention, combined with the in-flight polarization sensing method, allows the user to use a polarized laser light source with a high signal-to-noise ratio to effectively eliminate the natural light in the environment. The resulting background noise is affected and the ToF sensing technology is executed to further improve the accuracy and practicability of ranging.

The above is a description of the implementation of the present invention through specific specific examples. Those with ordinary knowledge in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention; all other equivalent changes or modifications made without departing from the spirit of the present invention should be included in the following patent scope Inside.

100: Time-of-flight ranging sensor 110: signal processing circuit 120: light transmitter 121: Light Transmitter 122: Light Transmitter 123: Light Transmitter 124: Light Transmitter 130: light sensor 200: sense target 410: light emitting array 420: first direction polarizer 430: second direction polarizer 440: light diffuser 440’: Light diffuser 531: the first sub-pixel repeating unit 532: second sub-pixel repeating unit B: Background noise signal B': background noise signal IR1: The first pulse light sensing unit IR2: second pulse light sensing unit P: Pulse signal P': Pulse signal P1: Pulse signal P1’: Pulse signal Sa: voltage signal Sb: voltage signal Sp: voltage signal T1: Time difference S210: Launch procedure S220: Sensing step S230: Calibration steps S240: Calculation steps

Figure 1 is a schematic diagram of the time-of-flight polarization sensing system of the present invention; 2 is a flow chart illustrating the steps of the time-of-flight polarization sensing method performed by the time-of-flight polarization sensing system of the present invention; 3 is a schematic diagram of a time-of-flight polarization sensing system according to an embodiment of the present invention; 4A is a schematic diagram of a light emitter according to an embodiment of the invention; 4B is a schematic diagram of a light emitter according to another embodiment of the invention; 4C is a schematic diagram of a light transmitter according to another embodiment of the present invention; 4D is a schematic diagram of a light emitter according to another embodiment of the invention; 5A is a schematic diagram of a first sub-pixel repeating unit according to an embodiment of the invention; 5B is a schematic diagram of a second sub-pixel repeating unit according to an embodiment of the invention; 6 is a timing diagram of multiple signal waveforms according to an embodiment of the present invention; FIG. 7 is a timing diagram of a pulse signal according to an embodiment of the present invention;

100: Time-of-flight ranging sensor

110: signal processing circuit

120: light transmitter

130: light sensor

Claims (17)

A time-of-flight polarization sensing system, including: A light emitter comprising at least one light emitting array, a first direction polarizer and a second direction polarizer, the first direction polarizer and the second direction polarizer are arranged on the at least one light emitting array, the After at least one light emitting array emits a pulsed light passing through the first direction polarizer, a first pulsed light having a first polarization direction is formed, and the at least one light emitting array emits a pulsed light passing through the second direction After the polarizer, a second pulsed light with a second polarization direction is formed; A light sensor, which is configured to sense a plurality of pulsed lights at the same time; and A signal processing circuit coupled to the light emitter and the light sensor; Wherein, the first pulsed light with the first polarization direction and the second pulsed light with the second polarization direction are emitted to a sensing target through the light emitter, and pass through the light sensor The first pulsed light and the second pulsed light reflected by the sensing target are sensed. The time-of-flight polarization sensing system according to the first item of the scope of patent application, wherein the first direction polarizer and the second direction polarizer are one of a birefringent crystal and a metal grating. In the time-of-flight polarization sensing system described in item 1 of the scope of patent application, the light emitter further includes a light diffuser, which is arranged on the light emitter. The time-of-flight polarization sensing system described in item 1 of the scope of patent application, wherein the light emitter further includes a light diffuser, and the first direction polarizer and the second direction polarizer are arranged on the light diffuser, And the light diffuser is arranged on the at least one light emitting array. The time-of-flight polarization sensing system described in item 1 of the scope of patent application, wherein the light emitter further includes a light diffuser, the first direction polarizer and the second direction polarizer are arranged in the light diffuser, And the light diffuser is arranged on the at least one light emitting array. The time-of-flight polarization sensing system according to claim 1, wherein the photo sensor outputs a first sensing signal through a first sub-pixel repeating unit and a second sub-pixel repeating unit Output a second sensing signal to the signal processing circuit, Wherein, the first sub-pixel repeating unit further includes a plurality of color sub-pixel units and a first pulsed light sensing unit having the first polarization direction, and the second sub-pixel repeating unit further includes a plurality of color sub-pixels. Pixel unit and a second pulsed light sensing unit having the second polarization direction, Wherein, the signal processing circuit determines a pulse signal according to the first sensing signal and the second sensing signal, and the signal processing circuit determines a pulse signal according to the first pulse light and the second pulse light and the pulse signals A piece of depth information of the sensing target. In the time-of-flight polarization sensing system described in item 6 of the scope of patent application, in a ranging period, the light sensor uses the first pulsed light sensing unit of the first sub-pixel repeating unit and the second The second pulsed light sensing unit of two sub-pixel repeating units obtains the first sensing signal and the second sensing signal. The time-of-flight polarization sensing system described in item 6 of the scope of patent application, wherein the signal processing circuit executes a time-of-flight ranging operation to emit the first pulsed light and the second pulsed light according to the sum of the first pulsed light and the second pulsed light emitted by the light emitter. The light sensor senses a time difference between the pulse signals to calculate the depth information of the sensing target. The time-of-flight polarization sensing system as described in item 6 of the scope of patent application, wherein the first sensing signal includes the pulse signal and a first background noise signal, and the second sensing signal includes a second background noise The signal strength of the first background noise signal and the second background noise signal are the same or similar, and the polarization directions of the first background noise signal and the second background noise signal are different. In the time-of-flight polarization sensing system described in item 9 of the scope of patent application, the signal processing circuit performs a signal intensity subtraction operation on the first sensing signal and the second sensing signal to obtain the pulse signal. As described in item 6 of the scope of patent application, the time-of-flight polarization sensing system, wherein the first pulsed light sensing unit and the second pulsed light sensing unit each have an infrared photo sub-pixel unit. The time-of-flight polarization sensing system described in item 6 of the scope of patent application, wherein the second polarization direction is orthogonal to the first polarization direction. A light emitter used in a time-of-flight polarization sensing system, the light emitter being coupled to a light sensor and a signal processing circuit of the time-of-flight polarization sensing system, the light transmitter comprising: At least one light emitting array, a first direction polarizer and a second direction polarizer, the first direction polarizer and the second direction polarizer are arranged on the at least one light emitting array, the at least one light emitting array emits After a pulsed light passes through the first direction polarizer, a first pulsed light with a first polarization direction is formed, and the at least one light emitting array emits a pulsed light after passing through the second direction polarizer to form a first pulsed light with a first polarization direction. A second pulsed light in a second polarization direction; Wherein, the first pulsed light with the first polarization direction and the second pulsed light with the second polarization direction are emitted to a sensing target through the light emitter, and pass through the light sensor The first pulsed light and the second pulsed light reflected by the sensing target are sensed. The time-of-flight polarization sensing system as described in item 13 of the scope of patent application, wherein the first direction polarizer and the second direction polarizer are one of a birefringent crystal and a metal grating. According to the time-of-flight polarization sensing system described in item 13 of the scope of patent application, the light emitter further includes a light diffuser, which is arranged on the light emitter. The time-of-flight polarization sensing system according to item 13 of the scope of patent application, wherein the light emitter further includes a light diffuser, and the first direction polarizer and the second direction polarizer are arranged on the light diffuser, And the light diffuser is arranged on the at least one light emitting array. The time-of-flight polarization sensing system according to item 13 of the scope of patent application, wherein the light emitter further includes a light diffuser, the first direction polarizer and the second direction polarizer are arranged in the light diffuser, And the light diffuser is arranged on the at least one light emitting array.

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