Image sensing device and operation method thereof

Abstract

An image sensing device and an operating method thereof, the operating method of the image sensing device is suitable for sensing a plurality of light emitting diodes, wherein the plurality of light emitting diodes respectively include a flickering cycle time, the image sensing device includes a plurality of pixel circuits, and the plurality of pixel circuits respectively include a first sensing circuit and a second sensing circuit, and the operating method includes: operating the image sensing device in a first operating mode. Operating the image sensing device in the first operating mode includes: performing light sensing by the first sensing circuit with a first exposure time longer than the flickering cycle time, thereby obtaining a first sensing result; performing light sensing by the first sensing circuit and the second sensing circuit with a second exposure time shorter than the flickering cycle time, thereby obtaining a second sensing result and a third sensing result; and determining whether the light emitting diode flickers according to the first, second, and third sensing results. The present disclosure maintains the LED detection capability under strong light without sacrificing the dynamic range.

Description

Technical Field

[0001] The present invention relates to an image sensing device and an operating method thereof, and more particularly to an image sensing device including sensing circuits with different sensitivities and an operating method thereof. Background Art

[0002] Since the light-emitting diodes (LEDs) of traffic lights are mostly controlled to flash at a specific frequency. Usually, the international standard (such as EN12966) is 90Hz or higher, so the exposure time for detecting LED signals needs to exceed 1 / 90 (11.1m / sec) to ensure that there is a way to detect each exposed LED signal. However, in strong light environments, the exposure time is shortened to achieve better scene detection, but the sensing ability of the LED may be sacrificed. Summary of the invention

[0003] Some embodiments of the present disclosure are related to an operating method of an image sensing device, which is suitable for sensing a plurality of light emitting diodes (LEDs), wherein the plurality of light emitting diodes respectively include a blinking cycle time, the image sensing device includes a plurality of pixel circuits, wherein the plurality of pixel circuits respectively include a first sensing circuit and a second sensing circuit, and the operating method includes the following steps: operating the image sensing device in a first operating mode. Operating the image sensing device in the first operating mode includes: performing light sensing by the first sensing circuit with a first exposure time longer than the blinking cycle time, thereby obtaining a first sensing result; performing light sensing by the first sensing circuit and the second sensing circuit with a second exposure time shorter than the blinking cycle time, thereby obtaining a second sensing result and a third sensing result; and determining whether the light emitting diode blinks according to the first sensing result, the second sensing result, and the third sensing result.

[0004] In some embodiments, a sensitivity of the first sensing circuit is lower than a sensitivity of the second sensing circuit.

[0005] In some embodiments, a size of the first sensing circuit is smaller than a size of the second sensing circuit.

[0006] In some embodiments, the method further includes: obtaining the second exposure time of the first sensing circuit and the second sensing circuit; and determining an operation mode of the image sensing device according to the second exposure time of the image sensing device.

[0007] In some embodiments, determining the operation mode of the image sensing device according to the second exposure time of the image sensing device includes: when the second exposure time of the image sensing device is shorter than the flashing cycle time, determining that the image sensing device is operating in the first operation mode.

[0008] In some embodiments, determining the operating mode of the image sensing device based on the exposure time of the image sensing device further includes: when the second exposure time of the image sensing device is greater than the flashing cycle time, determining that the image sensing device is operating in a second operating mode.

[0009] In some embodiments, operating the image sensing device in the second operating mode includes: simultaneously performing light sensing by the first sensing circuit and the second sensing circuit with a fourth exposure time longer than the flashing cycle time to obtain a fourth sensing result and a fifth sensing result; and determining whether the LED flashes based on the fourth sensing result and the fifth sensing result.

[0010] In some embodiments, the method further includes: after obtaining the first sensing result, temporarily storing the first sensing result by a storage circuit during a storage time.

[0011] In some embodiments, the method further includes: when the second sensing result and the third sensing result indicate that the LED does not flicker but the first sensing result indicates that the LED flickers, determining that the LED flickers.

[0012] In some embodiments, the method further includes: resetting a voltage of a floating node before respectively reading out the first sensing result, the second sensing result, and the third sensing result, wherein the floating node is coupled to the first sensing circuit and the second sensing circuit.

[0013] Some embodiments of the present disclosure relate to an operating method of an image sensing device, which is suitable for sensing multiple light-emitting diodes each including a flicker cycle time. The image sensing device includes multiple pixel circuits, and the multiple pixel circuits include multiple sensing circuits. The operating method includes: determining a first exposure time to sense whether there is flicker; and when it is determined that light sensing is performed with a first exposure time shorter than the flicker cycle time to sense whether there is LED flicker, before performing light sensing with the first exposure time shorter than the flicker cycle time, performing additional light sensing with a second exposure time longer than the flicker cycle time to increase the sensing accuracy of LED flicker.

[0014] In some embodiments, it also includes: at least one first sensing circuit among the multiple sensing circuits performs light sensing with the second exposure time longer than the flashing cycle time, thereby obtaining at least one first sensing result; and multiple second sensing circuits among the multiple sensing circuits simultaneously perform light sensing with a first exposure time shorter than the flashing cycle time, thereby obtaining multiple second sensing results.

[0015] In some embodiments, it further includes determining whether the LED flashes according to the at least one first sensing result and the plurality of second sensing results.

[0016] In some embodiments, at least two of the plurality of second sensing circuits have different sensitivities.

[0017] In some embodiments, the sensitivity of the at least one first sensing circuit is smaller than the sensitivity of at least one of the plurality of second sensing circuits.

[0018] Some embodiments of the present disclosure are related to an image sensing device, which is suitable for sensing a plurality of light-emitting diodes each including a flickering cycle time, the image sensing device including a plurality of pixel circuits, wherein each of the plurality of pixel circuits includes: a first sensing circuit, a second sensing circuit, and an output circuit. The first sensing circuit is used to perform light sensing with a first exposure time longer than the flickering cycle time, thereby obtaining a first sensing result. The first sensing circuit and the second sensing circuit are used to simultaneously perform light sensing with a second exposure time shorter than the flickering cycle time, thereby obtaining a second sensing result and a third sensing result. The output circuit is used to determine whether the LED flickers according to the first sensing result, the second sensing result, and the third sensing result.

[0019] In some embodiments, a sensitivity of the first sensing circuit is lower than a sensitivity of the second sensing circuit.

[0020] In some embodiments, a size of the first sensing circuit is smaller than a size of the second sensing circuit.

[0021] In some embodiments, each of the plurality of pixel circuits further comprises an output node, a floating node, a read circuit and a reset circuit. The read circuit is coupled between the floating node and the output node. The reset circuit is coupled to the floating node and is used to reset a voltage of the floating node before the read circuit reads out the first sensing result, the second sensing result and the third sensing result, respectively.

[0022] In some embodiments, each of the plurality of pixel circuits further includes a storage circuit for temporarily storing the first sensing result.

[0023] In summary, the present disclosure can maintain the LED detection capability under strong light without sacrificing the dynamic range by performing additional light emission sensing on the LED with an illumination time longer than the flashing cycle time under strong light environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the above and other objects, features, advantages and embodiments of the present disclosure more clearly understood, the accompanying drawings are described as follows:

[0025] Figure 1 is a schematic diagram of an image sensing device according to some embodiments of the present invention;

[0026] Figure 2 is a schematic diagram of a pixel circuit according to some embodiments of the present invention;

[0027] Figure 3 is a flow chart of an operation method of a pixel circuit according to some embodiments of the present invention;

[0028] Figure 4 is a flow chart of an operation method of a pixel circuit according to some embodiments of the present invention;

[0029] Figure 5 is a flow chart of an operation method according to some embodiments of the present case;

[0030] Figure 6 According to some embodiments of the present invention, Figure 5 Flow chart of step S520 in FIG.

[0031] Figure 7 According to some embodiments of the present invention, a Figure 5 A schematic diagram of the operation waveform of step S520 in FIG.

[0032] Figure 8 According to some embodiments of the present invention, Figure 5 A schematic diagram of the operation waveform of step S530 in FIG.

[0033] Fig. 9 According to some embodiments of the present invention, Figure 5 Schematic diagram of the operation waveform of step S530 in FIG.

[0034]

Explanation of symbols

[0035] 1: Image sensing device

[0036] 100:Pixel circuit

[0037] 110: Sensing circuit

[0038] 130: Sensing circuit

[0039] 150: Output circuit

[0040] 170: Control circuit

[0041] 190: Control circuit

[0042] 195: Control circuit

[0043] N1, N2: floating nodes

[0044] T1 to T7: Switch

[0045] S1, S2: Photodiode

[0046] C: Capacitor

[0047] 300, 400: Operation flow chart

[0048] TP1, TP2, TP3, TP4, TP5: time interval

[0049] 500: Operation method

[0050] S510, S515, S520, S530: Steps

[0051] S522, S524, S526: Steps

[0052] 700, 800, 900: Waveform

[0053] t0, t1, t2d1, t2a, t2b, t2d2, t3: time interval

[0054] t4, t5, t6, t7, t8: time interval DETAILED DESCRIPTION

[0055] As used herein, the term “coupled” may also refer to “electrically coupled”, and the term “connected” may also refer to “electrically connected.” “Coupled” and “connected” may also refer to two or more elements cooperating or interacting with each other.

[0056] In this article, the use of the words first, second, and third, etc., is to be understood as being used to describe various elements, components, regions, layers, and / or blocks. However, these elements, components, regions, layers, and / or blocks should not be limited by these terms. These words are limited to identifying a single element, component, region, layer, and / or block. Therefore, a first element, component, region, layer, and / or block hereinafter may also be referred to as a second element, component, region, layer, and / or block without departing from the original intention of the present invention. As used herein, the word "and / or" includes any combination of one or more of the listed associated items. The "and / or" mentioned in the present case document refers to any combination of any one, all, or at least one of the listed elements.

[0057] See also Figure 1 . Figure 1 is a schematic diagram of an image sensing device 1 according to some embodiments of the present invention. The image sensing device 1 is used to sense a plurality of light emitting diodes each having a flashing cycle time, wherein the flashing cycle time of the light emitting diodes may be different. Figure 1 As shown, the image sensing device 1 includes a plurality of pixel circuits 100 .

[0058] See also Figure 2 . Figure 2 is a schematic diagram of a pixel circuit 100 according to some embodiments of the present invention. Figure 2 As shown, the pixel circuit 100 includes a sensing circuit 110 , a sensing circuit 130 , and an output circuit 150 .

[0059] In terms of connection relationship, the sensing circuit 110, the sensing circuit 130 and the output circuit 150 are coupled to each other. For ease of description, the operation method 100 of the pixel circuit will refer to Figure 3 See Figure 3 . Figure 3 is a flow chart of an operation method 300 of a pixel circuit 100 according to some embodiments of the present invention.

[0060] Please also read Figure 2 as well as Figure 3 .like Figure 3 As shown in the figure, in the time interval TP1, the sensing circuit 110 is used to perform light sensing with an exposure time longer than the blinking cycle time to obtain a first sensing result. In the time interval TP2, the sensing circuit 110 and the sensing circuit 130 are operated with an exposure time shorter than the blinking cycle time to obtain a second sensing result and a third sensing result. In detail, the second sensing result is obtained by the sensing circuit 110, and the third sensing result is obtained by the sensing circuit 130.

[0061] In the time interval TP3, the output circuit 150 is used to determine whether the LED flashes according to the first sensing result, the second sensing result and the third sensing result.

[0062] In some embodiments, the sensitivity of the sensing circuit 110 is lower than the sensitivity of the sensing circuit 130. In some embodiments, the size of the sensing circuit 110 is smaller than the size of the sensing circuit 130. However, the implementation of the present case is not limited to the above.

[0063] Please refer again Figure 2 .like Figure 2 As shown, in some embodiments, the pixel circuit 100 further includes an output node N1, a floating node N2, a read circuit 170 and a reset circuit 190. In terms of connection, the read circuit 170 is coupled between the floating node N1 and the output node N2. The reset circuit 190 is coupled to the floating node N1.

[0064] In operation, the read circuit 170 is used to read out and transmit the first sensing result, the second sensing result and the third sensing result. The reset circuit 190 is used to reset the voltage of the floating node N1 before the read circuit 170 reads out the first sensing result, the second sensing result and the third sensing result.

[0065] like Figure 2 As shown, in some embodiments, the pixel circuit 100 further includes a storage circuit 195. After obtaining the first sensing result, the storage circuit 195 temporarily stores the first sensing result within a storage time.

[0066] It should be noted that if Figure 3 The operation flow chart 300 is operated in a strong light environment. In some embodiments, the exposure time for operation in the time interval TP2 is preset by the image sensing device 100 according to the ambient light. If the preset exposure time is shorter than the flash cycle time, the following is performed: Figure 3 The operation flow chart 300 is shown. Figure 4 If the preset exposure time is not shorter than the flashing cycle time, execute Figure 4 An operational flow chart 400 is depicted.

[0067] Figure 4 FIG. 4 is a flow chart of an operation method 400 of a pixel circuit 100 according to some embodiments of the present invention. Figure 4 As shown in the figure, in the time interval TP4, the sensing circuit 110 and the sensing circuit 130 simultaneously perform the light sensing exposure time with an exposure time (i.e., a preset exposure time), and the preset exposure time is longer than the flashing cycle time, so as to obtain the fourth sensing result and the fifth sensing result. In detail, the fourth sensing result is obtained by the sensing circuit 110, and the fifth sensing result is obtained by the sensing circuit 130.

[0068] In the time interval TP5, the output circuit 150 is used to determine whether the LED flashes according to the fourth sensing result and the fifth sensing result.

[0069] See also Figure 5 . Figure 5 is a flow chart of an operation method 500 according to some embodiments of the present invention. The operation method 500 includes steps S510, S515, S520 and S530. For ease of understanding, the following reference Figures 1 to 4 500. These operations are provided as examples. Additional operations are within the intended scope of the present invention. For example, in different embodiments, operations are provided before, during, and / or after the operations in the operating method 500, and / or some of the operations described are replaced or eliminated by other embodiments of the operating method 500, all within the intended scope of the present invention.

[0070] In step S510, a preset exposure time for sensing whether there is LED flicker is determined. In some embodiments, step S510 may be performed as follows: Figure 1The image sensing device 1 of the depicted type performs the preset exposure time according to the ambient light. When the ambient light is stronger, the preset exposure time is shorter.

[0071] In step S515, it is determined whether the preset exposure time is shorter than the flicker cycle time. The flicker cycle time is a characteristic of the LED to be sensed. It should be noted that the flicker cycle time is different between LEDs.

[0072] In some embodiments, step S515 is performed by Figure 2 The pixel circuit 100 shown in the figure or Figure 1 The image sensing device 1 shown in the figure operates. When the preset exposure time is shorter than the blinking cycle time, step S250 is executed. On the other hand, when the preset exposure time is not shorter than the blinking cycle time, step S530 is executed. That is, based on the preset exposure time obtained in step S510, the operation mode of the image sensing device 1 is determined based on the preset exposure time.

[0073] In step S520, the image sensing device is operated in the first operation mode. In some embodiments, step S520 can be performed by the sensing circuit 110 and the sensing circuit 130. The details of step S520 will be described below. Figure 6 Give a description.

[0074] Figure 6 According to some embodiments of the present invention, Figure 5 Flowchart of step S520 in FIG. 5 . Step S520 includes steps S522 to S526.

[0075] In step S522, the first sensing circuit performs light sensing with a first exposure time longer than the flashing period time, thereby obtaining a first sensing result. In some embodiments, step S522 may be performed as follows: Figure 2 The sensing circuit 110 is shown in the figure. For example, in some embodiments, the sensing circuit 110 performs light sensing with an exposure time longer than the flashing period time to obtain a first sensing result.

[0076] In some embodiments, after step S522 , the first sensing result is temporarily stored in the storage circuit 195 .

[0077] In step S524, the first sensing circuit and the second sensing circuit simultaneously perform light sensing with a second exposure time shorter than the flashing period time, thereby obtaining a second sensing result and a third sensing result. Figure 2 The sensing circuit 110 and the sensing circuit 130 shown in the figure perform In some embodiments, the second exposure time mentioned in step S524 is the preset exposure time mentioned in step S510.

[0078] For example, in step S524, in some embodiments, the sensing circuit 110 performs luminescence sensing with an exposure time shorter than the flashing cycle time to obtain a second sensing result, and the sensing circuit 130 performs luminescence sensing with an exposure time shorter than the flashing cycle time to obtain a third sensing result.

[0079] In step S526, it is determined whether the LED is flashing according to the first sensing result, the second sensing result and the third sensing result. In some embodiments, step S526 is performed as follows: Figure 2 In some embodiments, the first sensing result, the second sensing result and the third sensing result are transmitted to the output circuit 150 via the reading circuit 170 .

[0080] In step S526, if the second sensing result and the third sensing result indicate that there is no LED flickering but the first sensing result indicates that there is LED flickering, the output circuit 150 determines that there is LED flickering. In addition, if all of the first sensing results, the second sensing results, and the third sensing results indicate that there is no LED flickering, the output circuit 150 determines that there is no LED flickering. On the other hand, if all of the first sensing results, the second sensing results, and the third sensing results indicate that there is LED flickering, the output circuit 150 determines that there is LED flickering.

[0081] In step S526, in some embodiments, before the read circuit 170 reads out the first sensing result, the second sensing result, and the third sensing result, Figure 2 The voltage of the floating node N1 is shown to be reset by the reset circuit 190 .

[0082] Please refer again Figure 5 In step S530, the image sensing device is operated in the second operation mode. In some embodiments, step S530 is performed by Figure 2 The sensing circuit 110 and the sensing circuit 130 are shown.

[0083] Specifically, in step S530, the sensing circuit 110 and the sensing circuit 130 simultaneously perform light sensing with an exposure time longer than the flickering period time, so as to obtain a fourth sensing result and a fifth sensing result. In some embodiments, the exposure time in step S530 is the preset exposure time obtained in step S510. In step S530, the sensing circuit 110 obtains the fourth sensing result, and the sensing circuit 130 obtains the fifth sensing result. Then, the reading circuit 150 determines whether the LED flickers during the exposure period according to the fourth sensing result and the fifth sensing result.

[0084] That is, if the preset exposure time for sensing whether there is LED flicker is less than the flicker cycle time, additional light emission sensing with an exposure time longer than the flicker cycle time is performed to increase the sensing accuracy of LED flicker.

[0085] In some embodiments, please refer to Figure 3 . In time interval TP1, luminescence sensing can be performed by at least one sensing circuit with an exposure time longer than the flashing cycle time, thereby obtaining at least one first sensing result. In time interval TP2, luminescence sensing can be performed by multiple sensing circuits at the same time with an exposure time shorter than the flashing cycle time, thereby obtaining multiple second sensing results. In time interval TP3, whether the LED flashes is determined based on at least one first sensing result and the second sensing result. In some embodiments, the sensing circuits operating in time interval TP2 have different sensitivities from each other, and the sensitivity of the sensing circuit operating in time interval TP1 is lower than that of at least one sensing circuit operating in time interval TP2. However, the implementation of the present case is not limited to the above.

[0086] Please refer again Figure 2 In some embodiments, the sensing circuit 110 includes a photodiode S1 and a switch T1. The sensing circuit 130 includes a photodiode S1 and a switch T2. The reading circuit 170 includes switches T6 and T7. The reset circuit 190 includes a switch T5. The storage circuit 195 includes a capacitor and switches T3 and T4.

[0087] See also Figure 7 . Figure 7 According to some embodiments of the present invention, Figure 5 Schematic diagram of the operation waveform 700 of step S520 in FIG. Figure 2 right Figure 7 Provide explanation.

[0088] In the time interval t0, switches T1 to T7 are in the standby mode. In the time interval t1, switches T1 to T5 are turned on. In the time interval t2d1, only switch T5 is turned on to reset the voltage of the floating node N1. The photodiode S1 performs light sensing in the time interval t2d1 to obtain a first sensing result. In the time interval t2a, switch T2 is turned off, and switch T4 is turned on, so that the first sensing result obtained by the photodiode S1 can be transmitted to the capacitor C. In the time interval t2b, switch T4 is turned off, and switches T5, T2 and T1 are turned on. That is, in the time interval t2b, the first sensing result is stored in the capacitor C, the voltage of the floating node N1 is reset, and the voltages of the photodiodes S1 and S2 are also reset.

[0089] Next, in the time interval t2d2, the switches T1 to T4 are OFF, and the photodiodes S1 and S2 perform light sensing to obtain the second sensing result and the third sensing result. Before the time interval t3, the switch T5 is ON to reset the voltage of the floating node N1.

[0090] During the time interval t3 to t8, the switch T7 is turned on to read out the sensing result to the output circuit 150. Specifically, during the time interval t3, the switch T5 is turned on, and the voltage of the floating node N1 is reset. During the time interval t4, the switch T2 is turned on, and the third sensing result obtained by the photodiode S2 is transmitted to the reading circuit 170 and the output circuit 150. During the time interval t5, the switch T5 is turned on, and the voltage of the floating node N1 is reset. During the time interval t6, the switch T1 is turned on, and the second sensing result obtained by the photodiode S1 is transmitted to the reading circuit 170 and the output circuit 150. During the time interval t7, the switch T5 is turned on, and the voltage of the floating node N1 is reset. During the time interval t8, the switch T3 is turned on, and the first sensing result stored in the capacitor C is transmitted to the reading circuit 170 and the output circuit 150.

[0091] See also Figure 8 . Figure 8 According to some embodiments of the present invention, Figure 5 800 of the operation waveform of step S530 in FIG. Figure 2 right Figure 8 Provide explanation.

[0092] In time interval t0, all switches T1 to T7 are in a standby state. In time interval t1, switches T1 to T5 and T7 (except T6) are turned on. In time interval t2, only switch T5 is turned on to reset the voltage of floating node N1. In time interval t2, photodiode S1 performs light sensing to obtain a fourth sensing result, and photodiode S2 performs light sensing to obtain a fifth sensing result.

[0093] In the time interval t3 to t6, the switch T7 is turned on to read out the sensing result to the output circuit 150. Specifically, in the time interval t3, the switch T5 is turned on, and the voltage of the floating node N1 is reset. In the time interval t4, the switch T2 is turned on, and the fifth sensing result obtained by the photodiode S2 is transmitted to the reading circuit 170 and the output circuit 150. In the time interval t5, the switch T5 is turned on, and the voltage of the floating node N1 is reset. In the time interval t6, the switch T1 is turned on, and the fourth sensing result obtained by the photodiode S1 is transmitted to the reading circuit 170 and the output circuit 150.

[0094] See also Fig. 9 . Figure 8 According to some embodiments of the present invention, Figure 5 900 of the operation waveform of step S530 in FIG. Figure 2 right Fig. 9 Provide explanation.

[0095] Thus, when the photodiode S1 obtains the fourth sensing result, the capacitor C and the capacitance of the switch T4 can be used. The difference between the waveform 900 and the waveform 800 is that in the waveform 900, the switch T4 is turned on in the time interval from t1 to t6. Thus, when the photodiode S1 obtains the fourth sensing result, the capacitor C and the capacitance of the switch T4 can be used.

[0096] It should be noted that the order of transmitting the sensing results can be adjusted. Figures 7 to 9 The transmission order of the sensing results mentioned in the above is for illustration purposes only, and the implementation of the present invention is not limited thereto.

[0097] In some embodiments, the image sensing device 1 can be applied to an electronic rearview mirror where the user does not want to see a flashing image. The image sensing device 1 can also be applied to certain cars with ADAS (Advanced Driver Assistance System), which will detect traffic lights and speed limits. The image sensing device can also be other circuits with light sensing functions. The switches T1 to T7 can be PMOS transistors, NMOS transistors, or other circuits including switch functions.

[0098] It can be seen from the above embodiments that the embodiments of the present case provide an image sensing device and an operating method thereof, and more particularly, an image sensing device having sensing circuits with different sensitivities and an operating method thereof. By performing additional light emission sensing on the LED in a strong light environment with an exposure time longer than the flash cycle time, the LED sensing capability in strong light can be maintained without sacrificing dynamic range detection.

[0099] The above examples include sequential exemplary steps, but these steps do not have to be performed in the order shown. Performing these steps in different orders is within the scope of the present disclosure. Within the spirit and scope of the embodiments of the present disclosure, these steps can be added, replaced, changed in order and / or omitted as appropriate.

[0100] Although the present disclosure has been disclosed in the above embodiments, it is not intended to limit the present disclosure. Anyone with ordinary knowledge in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be based on the scope defined by the attached claims.

Claims

1. A method for operating an image sensing device, characterized in that: The image sensing device is suitable for sensing a plurality of light-emitting diodes (LEDs), each of which has a flashing cycle. The image sensing device includes a first sensing circuit and a second sensing circuit. The operating method includes: determining a first exposure time and a second exposure time; When the second exposure time is shorter than the flashing period, operating the image sensing device in a first operation mode; Simultaneously, the first sensing circuit and the second sensing circuit perform light sensing with the second exposure time to obtain a first sensing result and a second sensing result; performing additional light sensing with the first exposure time by the first sensing circuit to obtain a third sensing result, wherein the first exposure time is longer than the flashing cycle time; as well as Whether a light emitting diode flickers is determined according to the first sensing result, the second sensing result, and the third sensing result.

2. The operating method according to claim 1, characterized in that: A sensitivity of the first sensing circuit is lower than a sensitivity of the second sensing circuit.

3. The operating method according to claim 1, characterized in that: A size of the first sensing circuit is smaller than a size of the second sensing circuit.

4. The operating method according to claim 1, characterized in that Also includes: When the second exposure time of the image sensing device is greater than the blinking cycle time, it is determined that the image sensing device is operating in a second operation mode.

5. The operating method according to claim 4, characterized in that: Operating the image sensing device in the second operating mode includes: Simultaneously, the first sensing circuit and the second sensing circuit perform light sensing with a fourth exposure time longer than the flashing period, thereby obtaining a fourth sensing result and a fifth sensing result; as well as It is determined whether the LED flashes according to the fourth sensing result and the fifth sensing result.

6. The operating method according to claim 1, characterized in that: Also includes: During a storage time, after the third sensing result is obtained, a storage circuit temporarily stores the third sensing result.

7. The operating method according to claim 1, characterized in that: Also includes: When the second sensing result and the first sensing result indicate that the LED does not flicker but the third sensing result indicates that the LED flickers, it is determined that the LED flickers.

8. The operating method according to claim 1, characterized in that: Also includes: Before respectively reading out the first sensing result, the second sensing result, and the third sensing result, a voltage of a floating node is reset, wherein the floating node is coupled to the first sensing circuit and the second sensing circuit.

9. A method for operating an image sensing device, characterized in that: Suitable for sensing a plurality of light emitting diodes, each of which has a flashing cycle time, the operating method includes: determining a first exposure time shorter than the flashing cycle time; Obtaining a first sensing result by a first sensing circuit according to the first exposure time; Performing an additional light sensing operation by a second sensing circuit with a second exposure time longer than the flashing period to obtain a second sensing result; as well as It is determined whether the light emitting diode flickers according to the first sensing result and the second sensing result.

10. The operating method according to claim 9, characterized in that: The first sensing circuit and the second sensing circuit have different sensitivities.

11. The operating method according to claim 9, characterized in that: The sensitivity of the second sensing circuit is lower than that of the first sensing circuit.

12. An image sensing device, characterized in that: The image sensing device is suitable for sensing a plurality of light emitting diodes each having a flashing cycle time, and comprises a plurality of pixel circuits, wherein each of the plurality of pixel circuits comprises: a first sensing circuit for performing additional light sensing with a second exposure time longer than the blinking cycle when a first exposure time is shorter than a blinking cycle, thereby obtaining a first sensing result; a second sensing circuit, wherein the first sensing circuit and the second sensing circuit are configured to simultaneously perform light sensing with the first exposure time being shorter than the flashing period, thereby obtaining a second sensing result and a third sensing result; as well as An output circuit is used to determine whether the LED flickers according to the first sensing result, the second sensing result and the third sensing result.

13. The image sensing device according to claim 12, wherein: A sensitivity of the first sensing circuit is lower than a sensitivity of the second sensing circuit.

14. The image sensing device according to claim 12, wherein: A size of the first sensing circuit is smaller than a size of the second sensing circuit.

15. The image sensing device according to claim 12, wherein: wherein each of the plurality of pixel circuits further comprises: an output node; a floating node; a read circuit coupled between the floating node and the output node; as well as A reset circuit is coupled to the floating node and is used for resetting a voltage of the floating node before the read circuit reads out the first sensing result, the second sensing result and the third sensing result respectively.

16. The image sensing device according to claim 12, wherein: The plurality of pixel circuits further include: A storage circuit is used to temporarily store the first sensing result.

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