Control method of active pixel sensor, active pixel sensor, and electronic device

Abstract

The application relates to a control method of an active pixel sensor, the active pixel sensor and electronic equipment, the control method comprises the following steps: according to current illumination intensity, applying a high-voltage pulse signal with a predetermined period to a photocathode of the active pixel sensor in a subsequent frame period, and controlling a low-level duration of the high-voltage pulse signal, each frame period comprises a plurality of exposure intervals in sequence. One technical effect of the application is that, for a rolling shutter shooting process, the low-level duration of the photocathode in the subsequent frame period can be delayed controlled by the actual illumination intensity, the detection capability of the photocathode to weak light is utilized, and the shooting performance of the active pixel sensor in different illumination environments is improved.

Description

Technical Field

[0001] This invention relates to the field of active pixel sensor technology, and more specifically, to a control method for an active pixel sensor, an active pixel sensor, and an electronic device. Background Technology

[0002] Existing electronic devices such as cameras utilize electron-bombardment active pixel sensors to adapt to different lighting environments. In low-light conditions, the photocathode in an electron-bombardment active pixel sensor can be excited to produce electrons under light irradiation, and a high-voltage electric field is used to accelerate the electrons, bombarding them towards the pixel device layer.

[0003] However, current research on electron bombardment type active pixel sensors has not yet addressed how to control the photocathode of the active pixel sensor so that the active pixel sensor can better adapt to various lighting environments. Summary of the Invention

[0004] One objective of this invention is to provide a new technical solution for a control method for an active pixel sensor, an active pixel sensor, and an electronic device.

[0005] According to a first aspect of the present invention, a control method for an active pixel sensor for a rolling shutter is provided, the control method comprising:

[0006] Step S101: Repeat the detection of the current light intensity according to the detection cycle;

[0007] Step S102: Compare the current light intensity with the predetermined light intensity;

[0008] Step S201: If the current light intensity is less than the predetermined light intensity, the active pixel sensor is adjusted to enter the first working mode.

[0009] Step S202: Based on the current light intensity, apply a high-voltage pulse signal of a predetermined period to the photocathode of the active pixel sensor in subsequent frame cycles, and control the low-level duration of the high-voltage pulse signal. Each frame cycle includes multiple sequential exposure intervals.

[0010] Optionally, the duration of the exposure interval is Q times the predetermined period, where Q is an integer from 1 to 10.

[0011] Optionally, each predetermined cycle includes a pulse interval in which a high-voltage pulse signal is applied;

[0012] The pulse interval is configured within the exposure interval, and the duration of the pulse interval is less than or equal to the duration of the exposure interval.

[0013] Optionally, the predetermined period is one-P times the frame period of the active pixel sensor, where P is a positive integer greater than 1.

[0014] Optionally, the start time of each frame period is aligned with the rising edge of the exposure signal; within a frame period, the start time of the first predetermined period is aligned with the rising edge of the exposure signal.

[0015] Optionally, step S202 includes:

[0016] Based on the current light intensity and light strength standard, obtain the duty cycle of the low-level duration corresponding to the high-voltage pulse signal in the subsequent frame period;

[0017] The duration of the low level in subsequent frame periods is adjusted according to the duty cycle.

[0018] Optionally, the light intensity standard is represented by a grayscale value;

[0019] Step S202 includes calculating the average gray value of the active pixel sensor in the current frame period.

[0020] Optionally, the average grayscale value can be converted into the duty cycle using a preset function, so that the duty cycle is inversely proportional to the average grayscale value.

[0021] Optionally, the duty cycle remains constant within one frame period.

[0022] Optionally, the detection period is N times the frame period, where N is any integer from 1 to 5.

[0023] Optionally, step S202 includes: starting from the Mth subsequent frame period, applying a high-voltage pulse signal to the photocathode and controlling the low-level duration, where M is any integer from 1 to 5.

[0024] Optionally, each frame cycle also includes a read interval;

[0025] The pulse interval and the reading interval partially overlap.

[0026] Optionally, the control method further includes:

[0027] Step S301: If the current light intensity is greater than the predetermined light intensity, the active pixel sensor is adjusted to enter the second working mode.

[0028] Step S302: Cancel the application of the high-voltage pulse signal to the photocathode of the active pixel sensor.

[0029] Optionally, adjusting the active pixel sensor into a first operating mode includes: adjusting the lens assembly to focus the image on the photocathode;

[0030] Adjusting the active pixel sensor into a second operating mode includes: adjusting the lens assembly to focus the image on the pixel device layer of the active pixel sensor.

[0031] According to a second aspect of the present invention, an active pixel sensor for a rolling shutter is provided for performing the control method described above, the active pixel sensor comprising:

[0032] The detection module is used to repeatedly detect the current light intensity according to a detection cycle;

[0033] The comparison module is used to compare the current light intensity with a predetermined light intensity.

[0034] An adjustment module is used to adjust the active pixel sensor into a first working mode when the current light intensity is less than a predetermined light intensity.

[0035] The control module is used to apply a high-voltage pulse signal of a predetermined period to the photocathode of the active pixel sensor in subsequent frame cycles according to the current light intensity, and to control the low-level duration of the high-voltage pulse signal. Each frame cycle includes multiple sequential exposure intervals.

[0036] Optionally, the adjustment module is further configured to adjust the active pixel sensor into a second working mode when the current light intensity is greater than a predetermined light intensity;

[0037] The control module is also used to cancel the application of a high-voltage pulse signal to the photocathode of the active pixel sensor.

[0038] According to a third aspect of the present invention, an electronic device is provided, characterized in that the electronic device includes the above-described active pixel sensor.

[0039] One technical advantage of this invention is that, for the shooting process of a rolling shutter, the low-level duration of the photocathode in subsequent frame cycles can be controlled by delaying the actual light intensity, thereby improving the shooting performance of the active pixel sensor under different lighting conditions by utilizing the photocathode's ability to detect weak light.

[0040] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0041] The accompanying drawings, which form part of this specification, illustrate embodiments of the invention and, together with the specification, serve to explain the principles of the invention.

[0042] Figure 1This is one of the control methods for the active pixel sensor of the rolling shutter in the embodiments of this disclosure.

[0043] Figure 2 This is a second control method for the active pixel sensor of the rolling shutter in this embodiment of the present disclosure.

[0044] Figure 3 This is one of the partial periodic schematic diagrams of the active pixel sensor of the rolling shutter in the embodiments of this disclosure.

[0045] Figure 4 This is the second partial periodic schematic diagram of the active pixel sensor of the rolling shutter in this embodiment of the present disclosure.

[0046] Figure 5 This is a schematic diagram of the control delay of the active pixel sensor of the rolling shutter in an embodiment of this disclosure.

[0047] Figure 6 This is one of the schematic diagrams showing the duty cycle and illumination level of the active pixel sensor of the rolling shutter in this embodiment of the present disclosure.

[0048] Figure 7 This is the second schematic diagram of the duty cycle and illumination level of the active pixel sensor of the rolling shutter in this embodiment of the present disclosure.

[0049] Figure 8 This is a schematic diagram of the active pixel sensor of the rolling shutter in an embodiment of this disclosure.

[0050] Explanation of reference numerals in the attached figures:

[0051] 1. Detection module; 2. Comparison module; 3. Adjustment module; 4. Control module; 100. Active pixel sensor. Detailed Implementation

[0052] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0053] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0054] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0055] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0056] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0057] According to a first aspect of this application, a control method for an active pixel sensor used in a rolling shutter is provided. It is worth noting that the active pixel sensor in this application refers to an electron impact type active pixel sensor.

[0058] In the active pixel sensor of a rolling shutter, each row of pixels is exposed independently and sequentially, so that the entire image is also exposed in stages. All detection modules of the active pixel sensor of the rolling shutter collect incident light and are exposed independently.

[0059] like Figure 1 As shown, the control method includes: step S101, repeatedly detecting the current light intensity according to the detection cycle.

[0060] Specifically, in this embodiment, the detection period refers to detecting the current light intensity once every certain number of frame periods to obtain the current light intensity. Different detection periods can be selected according to different light intensity detection requirements to perform corresponding light intensity detection. By setting a certain detection period, this embodiment can repeatedly detect the current light intensity according to that period, so as to obtain the light intensity reflecting the current actual light environment even when the lighting environment changes. Setting the detection period also makes the light intensity detection process more flexible, avoiding excessive data volume caused by real-time detection that could affect the power consumption of the active pixel sensor. Multiple detection modules can be used to detect the current light intensity to improve the detection accuracy.

[0061] Step S102: Compare the current light intensity with the predetermined light intensity.

[0062] The predetermined illumination intensity is data pre-configured in the register of the active pixel sensor and can be adjusted as needed via a computer program. In this embodiment, the predetermined illumination intensity serves as a standard for distinguishing between the first and second operating modes, as well as between low and high illumination levels. This embodiment utilizes a comparator within the active pixel sensor to compare the current illumination intensity with the predetermined illumination intensity.

[0063] Step S201: If the current light intensity is less than the predetermined light intensity, the active pixel sensor is adjusted to enter the first working mode.

[0064] Specifically, after obtaining in step S102 that the current light intensity is less than a predetermined light intensity, the active pixel sensor is adjusted to enter a first working mode, which can be a nighttime working mode. In this embodiment, when the current light intensity is found to be less than a predetermined light intensity, it is determined that the current environment is nighttime or low-light, and the active pixel sensor is adjusted to enter the first working mode.

[0065] When the current light intensity is less than the predetermined light intensity, and the active pixel sensor is adjusted to the first operating mode, i.e., the night operating mode, the photocathode of the active pixel sensor is energized. The photocathode can excite electrons under light illumination. Typically, the active pixel sensor is set to maintain a ground potential, and the photocathode is set to a low potential. A high-voltage electric field is applied between the photocathode and the pixel device layer of the active pixel sensor. This high-voltage electric field can accelerate the electrons excited by the photocathode, causing the electrons to collide with the pixel device layer. Electron multiplication occurs within the pixel device layer, and the electrons are collected. This facilitates the detection of weak light in nighttime or low-light environments, thereby improving the detection capability and application range of the active pixel sensor.

[0066] Step S202: Based on the current light intensity, apply a high-voltage pulse signal of a predetermined period to the photocathode of the active pixel sensor in subsequent frame cycles, and control the low-level duration of the high-voltage pulse signal. Each frame cycle includes multiple sequential exposure intervals.

[0067] Specifically, the predetermined period is the period of the high-voltage pulse signal applied to the photocathode of the active pixel sensor. In this embodiment, after the active pixel sensor is adjusted to a first operating mode, i.e., a nighttime operating mode, a high-voltage pulse signal of the predetermined period can be applied to the photocathode of the active pixel sensor in subsequent frame periods according to the current light intensity, so that the photocathode of the active pixel sensor is energized, thereby enabling the photocathode to emit electrons under light irradiation. For example, in... Figure 4 Within two consecutive frame periods, a high-voltage pulse signal of a predetermined period is applied to the photocathode of the active pixel sensor. Compared with the low-level duration of the high-voltage pulse signal in the previous predetermined period, the low-level duration of the high-voltage pulse signal in the subsequent predetermined period is longer, that is, the photocathode is turned on for a longer period.

[0068] Typically, an active pixel sensor maintains a grounded potential. The high-voltage pulse signal applied to the photocathode is a negative voltage pulse signal. Therefore, when the high-voltage pulse signal is at a low level, a high-voltage electric field is formed in the gap between the photocathode and the pixel device layer of the active pixel sensor. This high-voltage electric field can accelerate the electrons excited by the photocathode, causing the electrons to collide with the pixel device layer to undergo electron multiplication and electron collection, thereby enabling the active pixel sensor to detect weak light in nighttime environments.

[0069] Furthermore, the low-level duration of the high-voltage pulse signal is the on-time of the photocathode within a predetermined cycle. During this low-level time, the photocathode can excite electrons under light irradiation. The high-voltage electric field disposed between the photocathode and the pixel device layer of the active pixel sensor accelerates the electrons excited by the photocathode, causing them to collide with the pixel device layer for electron multiplication and collection. This embodiment of the application can change the low-level duration of the high-voltage pulse signal, thereby changing the on-time of the photocathode within a predetermined cycle. This, in turn, changes the amount of electrons excited by the photocathode under light irradiation and the amount of electrons accelerated by the high-voltage electric field formed between the photocathode and the pixel device layer. This adjusts the total amount of electrons colliding with the pixel device layer, thereby altering the active pixel sensor's ability to detect weak light in nighttime environments, facilitating imaging in low-light conditions.

[0070] This embodiment controls the low-level duration of the high-voltage pulse signal in subsequent frame cycles based on the current light intensity. This allows control over the amount of electrons excited by the photocathode under light irradiation and the amount of electrons accelerated by the high-voltage electric field formed between the photocathode and the pixel device layer in subsequent frame cycles. This enables control over the detection capability of the active pixel sensor in weak light within subsequent frame cycles. It is worth noting that controlling the low-level duration of the high-voltage pulse signal in subsequent frame cycles based on the current light intensity in this embodiment refers to controlling the low-level duration of the high-voltage pulse signal from the start of the subsequent frame cycle. This ensures that the low-level duration of all high-voltage pulse signals remains consistent within the same frame cycle, avoiding inconsistent gain among pixels within a frame cycle and ensuring the stability of the image gain level throughout the frame cycle.

[0071] like Figure 3 and Figure 4As shown, this embodiment of the application sets each frame period to include multiple sequential exposure intervals, within which all images are exposed independently and sequentially. Furthermore, this embodiment of the application controls the low-level duration of the high-voltage pulse signal in subsequent frame periods based on the current illumination intensity, while maintaining the low-level duration of the high-voltage pulse signal unchanged in the current frame period. This delay control avoids the problem of inconsistent gain among pixels in a frame period, ensuring the stability of the image gain level in the frame period. Furthermore, it also avoids errors in the detected illumination intensity results caused by unstable gain levels of pixels in a single frame, preventing confusion in the low-level duration control of subsequent frame periods, and improving the imaging reliability and controllability of the active pixel sensor.

[0072] This application embodiment can change the low-level duration of the high-voltage pulse signal in the subsequent frame period by delay control, thereby changing the turn-on time of the photocathode in the subsequent frame period. This can change the amount of electrons excited by the photocathode when it is irradiated by light, as well as the amount of electrons accelerated by the high-voltage electric field formed between the photocathode and the pixel device layer. This adjusts the total amount of electrons hitting the pixel device layer, thereby changing the detection capability of the active pixel sensor in weak light in nighttime environments, making it easier for the active pixel sensor to image in low-light environments.

[0073] Optionally, the duration of the exposure interval is Q times the predetermined period, where Q is an integer from 1 to 10.

[0074] like Figure 4 As shown, in this embodiment, the exposure interval duration is set to Q times a predetermined period, meaning one exposure interval contains Q high-voltage pulse signals. This allows for more flexible matching of the high-voltage pulse signals and the exposure of each row of pixels, improving the gain level of the active pixel sensor. Depending on the actual design requirements, Q can be any integer from 1 to 10. When Q is 1, one exposure interval contains one high-voltage pulse signal, and the gain level of the active pixel sensor can be adjusted by changing the low-level duration of this high-voltage pulse signal. When the active pixel sensor has a more complex circuit design, Q can be set to 10, meaning one exposure interval contains 10 high-voltage pulse signals.

[0075] Optionally, each predetermined cycle includes a pulse interval in which a high-voltage pulse signal is applied;

[0076] The pulse interval is configured within the exposure interval, and the duration of the pulse interval is less than or equal to the duration of the exposure interval.

[0077] The pulse interval is the time interval during which the photocathode is turned on within a predetermined period T. Since a negative high voltage is generally applied to the photocathode, the time interval during which the photocathode is turned on is also... Figure 3 The low-level range in the middle.

[0078] This application embodiment configures the pulse interval within the exposure interval. By adjusting the duration of the pulse interval within a predetermined period, the amount of electrons excited by the photocathode and the number of electrons accelerated by the high-voltage electric field within the corresponding exposure interval can be adjusted. This, in turn, adjusts the active pixel sensor's ability to detect weak light in nighttime or low-light environments. This application embodiment sets the pulse interval duration to be less than or equal to the exposure interval duration. This allows the active pixel sensor to achieve imaging while avoiding the lifespan degradation caused by prolonged photocathode operation, thus extending the sensor's lifespan.

[0079] This application embodiment can adjust the duration of the pulse interval within a predetermined period by adjusting the duty cycle, thereby adjusting the active pixel sensor's ability to detect weak light in nighttime environments to adapt to different nighttime conditions. For example... Figure 4 In the process, the duration of the corresponding pulse interval, i.e. the duty cycle, is different in two consecutive frame periods. When the lighting environment is detected to be dark in the frame period where T1 is located, the duration of the pulse interval in the frame period where T2 is located is set to be longer, that is, the on time of the photocathode in the frame period where T2 is located is longer, so as to enhance the gain level of the active pixel sensor in the frame period where T2 is located.

[0080] Optionally, the predetermined period is one-P times the frame period of the active pixel sensor, where P is a positive integer greater than 1.

[0081] In this embodiment, the predetermined period is set to 1 / P of the frame period of the active pixel sensor, where P is a positive integer greater than 1. That is, the period of the high-voltage pulse signal applied to the photocathode is equal to 1 / P of the frame period of the active pixel sensor, ensuring that the frame period of the active pixel sensor and the period of the high-voltage pulse signal applied to the photocathode are not coprime. This guarantees that the high-voltage pulse signal can be matched to the entire exposure range within one frame period, avoiding the abnormal situation where some pixels cannot be exposed, and improving the imaging reliability of the active pixel sensor. Specifically, P is set to any positive integer greater than 1 based on factors such as the frame period of the active pixel sensor, the period of the high-voltage pulse signal applied to the photocathode, the pixel size, and the readout rate during actual design.

[0082] In another embodiment, when there is a remainder between the frame period of the active pixel sensor and a multiple of the predetermined period, the remainder needs to be set as the blanking time. In order to reduce the ineffective exposure of individual pixels caused by the blanking time, the predetermined period can be appropriately reduced to reduce the blanking time.

[0083] Optionally, the start time of each frame period is aligned with the rising edge of the exposure signal; within a frame period, the start time of the first predetermined period is aligned with the rising edge of the exposure signal.

[0084] In this embodiment, the start time of each frame period is aligned with the rising edge of the exposure signal to enable the exposure signal to be used as the start of a frame period. Within a frame period, the start time of the first predetermined period is aligned with the rising edge of the exposure signal, meaning the start time of the first predetermined period within a frame period is aligned with the start time of that frame period. This configuration ensures that the delay control of the low-level duration of the high-voltage pulse signal in subsequent frame periods can be performed from the beginning of a frame, guaranteeing that the low-level duration of all high-voltage pulse signals remains consistent within a frame period. This avoids inconsistent gain among pixels within a frame period, thereby ensuring the stability of the image gain level within the frame period.

[0085] Optionally, step S202 includes:

[0086] Based on the current light intensity and light strength standard, obtain the duty cycle of the low-level duration corresponding to the high-voltage pulse signal in the subsequent frame period;

[0087] The duration of the low level in subsequent frame periods is adjusted according to the duty cycle.

[0088] Specifically, the light intensity standard serves as a basis for measuring the current light intensity. In this embodiment, the current light intensity can be matched to a specific light intensity value based on the light intensity standard. Different light intensities correspond to different light intensity values, meaning the light intensity value represents the current light intensity. Based on this light intensity value, this embodiment calculates the duty cycle of the low-level duration of the high-voltage pulse signal in subsequent frame periods, and adjusts the low-level duration in subsequent frame periods according to the calculated duty cycle, ensuring that the proportion of the photocathode's on-time in subsequent frame periods relative to its predetermined period satisfies the duty cycle.

[0089] Based on the duty cycle obtained from the current light intensity and light strength standard, the embodiments of this application can adjust the low-level duration in subsequent frame cycles, thereby changing the on-time of the photocathode in subsequent frame cycles. This changes the amount of electrons excited by the photocathode when exposed to light, as well as the amount of electrons accelerated by the high-voltage electric field formed between the photocathode and the pixel device layer. This adjusts the total amount of electrons hitting the pixel device layer, thereby changing the active pixel sensor's ability to detect weak light in nighttime environments, facilitating imaging of the active pixel sensor in low-light environments.

[0090] Optionally, the light intensity standard is represented by a grayscale value;

[0091] Step S202 includes calculating the average gray value of the active pixel sensor in the current frame period.

[0092] Specifically, due to the different colors and brightness of various points in a scene, each point in a black-and-white photograph taken by a camera or a black-and-white image reproduced by a television receiver appears to be of different shades of gray. Based on this, the relationship between white and black is divided into several levels according to a logarithmic relationship. The grayscale value range is generally from 0 to 255, with white being 255 and black being 0. In this embodiment, the light intensity standard is set using grayscale values, meaning the light intensity standard can correspond to an appropriate and standard grayscale value. Furthermore, the current light intensity can also be matched to a grayscale value; different light intensities correspond to different grayscale values, meaning that this grayscale value can represent the current light intensity.

[0093] This application embodiment calculates the average grayscale value of the pixels in the current frame period of the active pixel sensor, thereby obtaining the duty cycle of the low-level duration of the high-voltage pulse signal in subsequent frame periods. Based on this duty cycle, the low-level duration in subsequent frame periods can be adjusted to change the on-time of the photocathode in subsequent frame periods, thereby ultimately adjusting the active pixel sensor's ability to detect weak light in nighttime environments.

[0094] Depending on the actual layout of the detection modules or the detection requirements, the average gray value of the active pixel sensor in a specific area can be calculated, as well as the average gray value of the active pixel sensor in some pixels scattered in the array. The duty cycle of the low-level duration of the high-voltage pulse signal in the subsequent frame period can be obtained, and the low-level duration in the subsequent frame period can be adjusted according to the duty cycle.

[0095] In another embodiment of this application, the light intensity standard can also be represented by a time, that is, the light intensity standard can correspond to an appropriate and standard time. Furthermore, different light intensities can be matched to different times, meaning that time can also represent the current light intensity. Step S202 includes calculating the median of the active pixel sensor at the current frame period time, obtaining the duty cycle of the low-level duration corresponding to the high-voltage pulse signal in subsequent frame periods based on the median of the current frame period time, and adjusting the low-level duration in subsequent frame periods according to the duty cycle.

[0096] Optionally, the average grayscale value can be converted into the duty cycle using a preset function, so that the duty cycle is inversely proportional to the average grayscale value.

[0097] Specifically, the average grayscale value can be converted using a preset function pre-configured in the register of the active pixel sensor. This average grayscale value is then converted into a duty cycle that is inversely proportional to the average grayscale value, and the duration of the low-level signal in subsequent frame periods is adjusted based on this duty cycle. For example... Figure 6and Figure 7 As shown, the duty cycle is inversely proportional to the average grayscale value. A smaller average grayscale value indicates lower current light intensity, requiring a stronger detection capability from the active pixel sensor, meaning a longer low-level duration corresponding to the high-voltage pulse signal, and consequently a larger duty cycle. Conversely, a larger average grayscale value indicates higher current light intensity, requiring a weaker detection capability from the active pixel sensor, meaning a shorter low-level duration corresponding to the high-voltage pulse signal, and consequently a smaller duty cycle.

[0098] This embodiment of the application sets the duty cycle to be inversely proportional to the average grayscale value. This allows for adjustment of the duty cycle based on different light intensities, thereby regulating the low-level duration of the high-voltage pulse signal. This adapts to various nighttime or low-light environments while preventing prolonged operation of the photocathode, thus extending the lifespan of the active pixel sensor. This embodiment of the application also allows for convenient adjustment of the low-level duration of the high-voltage pulse signal using the duty cycle, and the adjustment process is simple and controllable.

[0099] Furthermore, embodiments of this application can convert the grayscale value representing the current illumination intensity into the required duty cycle according to a preset function for subsequent frame period control. That is, the duty cycle can dynamically change with the detected current illumination intensity, enabling the active pixel sensor to automatically adjust the duty cycle in the first operating mode to adapt to changing low-light environments.

[0100] Optionally, the duty cycle remains constant within one frame period.

[0101] Specifically, in this embodiment of the application, the duty cycle remains constant within a frame period, for example... Figure 5 When a new duty cycle is calculated at point A, the low-level duration of the high-voltage pulse signal can only be adjusted at the rising edge of the exposure signal at point B in the next frame. The rising edge of this exposure signal coincides with the falling edge of the reset signal for the first exposure row. Based on this setting, the embodiments of this application ensure that the low-level duration of the high-voltage pulse signal is the same during the sequential exposure of all images within a frame period. This avoids inconsistent gain among pixels in the current frame period and guarantees the stability of the image gain level in the current frame period. Furthermore, it avoids errors in the detected illumination intensity due to unstable image gain levels in a frame, preventing confusion in the low-level duration control of subsequent frame periods. This also improves the reliability and controllability of light detection by the active pixel sensor.

[0102] Optionally, the detection period is N times the frame period, where N is any integer from 1 to 5.

[0103] Specifically, in this embodiment, the detection period for the current light intensity is set to N times the frame period, meaning that the light intensity is detected once every N frame periods, and subsequent steps are performed based on the light intensity. N can be any integer from 1 to 5, depending on factors such as the actual processing speed and power consumption of the active pixel sensor. When the active pixel sensor needs to adapt more flexibly to different nighttime environments or varying degrees of low light, a smaller N can be chosen to make the detection of the current light intensity more frequent; when the nighttime or low light environment tends to be stable, a larger N can be chosen to avoid excessively frequent detection of the current light intensity and reduce the power consumption of the active pixel sensor.

[0104] Optionally, step S202 includes: starting from the Mth subsequent frame period, applying a high-voltage pulse signal to the photocathode and controlling the low-level duration, where M is any integer from 1 to 5.

[0105] Specifically, in this embodiment, after detecting the light intensity, starting from the Mth subsequent frame period (calculated from the current frame), a high-voltage pulse signal is applied to the photocathode and the low-level duration is controlled to adjust the on-time of the photocathode starting from the Mth subsequent frame period. This adjusts the detection capability of the active pixel sensor for weak light in nighttime environments starting from the Mth subsequent frame period, enabling the active pixel sensor to adapt to different nighttime environments.

[0106] Depending on the actual design and image detection requirements, M can be any integer from 1 to 5. When the active pixel sensor needs to be able to adapt more flexibly to different nighttime or low-light environments in order to clearly detect images, a smaller M can be selected to make the low-level time adjustment more frequent to enhance the detection capability. When the nighttime or low-light environment tends to be stable, a larger M can be selected to maintain a constant low-level time for several consecutive frame periods to avoid the power-on time adjustment being too frequent, thereby also avoiding excessive power consumption of the active pixel sensor.

[0107] Additionally, for the aforementioned N and M, both can be set to 1, meaning the light intensity is detected once per frame cycle, and a high-voltage pulse signal is applied to the photocathode and its low-level duration is controlled starting from the next frame cycle. This allows for rapid adjustment of the photocathode's on-time in the next frame based on the constantly changing light intensity, thereby adjusting the detection capability of the active pixel sensor. Alternatively, N and M can be set to other combinations of numbers, such as N=2 and M=1, meaning the light intensity is detected once every 2 frame cycles, and a high-voltage pulse signal is applied to the photocathode and its low-level duration is controlled starting from the next frame cycle. In this case, the detection cycle is 2 and the control delay is 1. Or, N=2 and M=2, meaning the light intensity is detected once every 2 frame cycles, and a high-voltage pulse signal is applied to the photocathode and its low-level duration is controlled starting from the second frame cycle. This avoids excessive power consumption of the active pixel sensor, and in this case, the detection cycle is 2 and the control delay is 2. To utilize the light intensity detection that best reflects the current lighting environment and reduce computational load, M can be set to be less than or equal to N.

[0108] Optionally, each frame cycle also includes a read interval;

[0109] The pulse interval and the reading interval partially overlap.

[0110] In this embodiment, each frame period also includes a readout interval, which is located after the exposure interval of each pixel. That is, after each pixel has completed exposure to collect electrical signals, the readout circuit in the active pixel sensor can output these electrical signals in video form.

[0111] Optionally, the control method further includes:

[0112] Step S301: If the current light intensity is greater than the predetermined light intensity, the active pixel sensor is adjusted to enter the second working mode.

[0113] Step S302: Cancel the application of the high-voltage pulse signal to the photocathode of the active pixel sensor.

[0114] like Figure 2 As shown, after repeatedly detecting the current light intensity according to the detection cycle and comparing the current light intensity with the predetermined light intensity, if the current light intensity is greater than the predetermined light intensity, it is determined that the current environment is daytime or high-light environment, and the active pixel sensor is adjusted to enter the second working mode, i.e., the daytime working mode. When the active pixel sensor enters the daytime working mode, the high-voltage pulse signal applied to the photocathode of the active pixel sensor is canceled to prevent the photocathode from being excited to emit electrons again. At this time, the incident light can pass through the photocathode, and the pixel device layer of the active pixel sensor can directly receive the incident light for imaging.

[0115] In this embodiment, after comparing the current light intensity with a predetermined light intensity, the active pixel sensor is adjusted to enter daytime working mode, and the high-voltage pulse signal applied to the photocathode of the active pixel sensor is canceled. This can avoid the lifespan damage caused by the photocathode working in strong daylight, and extend the service life of the active pixel sensor.

[0116] Optionally, adjusting the active pixel sensor into a first operating mode includes: adjusting the lens assembly to focus the image on the photocathode;

[0117] Adjusting the active pixel sensor into a second operating mode includes: adjusting the lens assembly to focus the image on the pixel device layer of the active pixel sensor.

[0118] Specifically, when the current light intensity is found to be less than a predetermined light intensity, the active pixel sensor is adjusted to enter the first working mode, i.e., the night working mode. A high-voltage pulse signal is applied to the photocathode of the active pixel sensor to activate it. The lens assembly is adjusted so that the image is focused on the photocathode, allowing the energized photocathode to be illuminated and excite electrons. The high-voltage electric field formed in the gap between the photocathode and the pixel device layer accelerates the electrons entering the gap, causing them to collide with the pixel device layer, where electron multiplication and collection occur, thereby achieving imaging in nighttime or low-light environments.

[0119] After determining that the current light intensity is greater than the predetermined light intensity, the active pixel sensor is switched to the second operating mode, i.e., the daytime operating mode. The high-voltage pulse signal applied to the photocathode of the active pixel sensor to disable its electron-excitation function under light is removed. The lens assembly is adjusted to focus the image on the pixel device layer of the active pixel sensor. At this point, the photocathode only serves to transmit light, allowing the pixel device layer of the active pixel sensor to directly receive incident light for imaging.

[0120] According to the different operating modes of the active pixel sensor, this application embodiment can adjust the lens assembly accordingly to adjust the focus position of the image, and control the on and off of the photocathode to achieve imaging in different environments such as day and night, thereby improving the detection capability of the active pixel sensor. In addition, by controlling the on and off of the photocathode, the lifespan of the photocathode caused by working in strong sunlight during the day can be avoided, thus extending the service life of the active pixel sensor.

[0121] According to a second aspect of this application, an active pixel sensor 100 for a rolling shutter is provided for executing the control method described above, the active pixel sensor 100 comprising:

[0122] Detection module 1, the detection module 1 is used to repeatedly detect the current light intensity according to the detection cycle;

[0123] Comparison module 2, which is used to compare the current light intensity with the predetermined light intensity;

[0124] Adjustment module 3 is used to adjust the active pixel sensor 100 into a first working mode when the current light intensity is less than a predetermined light intensity.

[0125] The control module 4 is used to apply a high-voltage pulse signal of a predetermined period to the photocathode of the active pixel sensor 100 in subsequent frame cycles according to the current light intensity, and to control the low-level duration of the high-voltage pulse signal. Each frame cycle includes multiple sequential exposure intervals.

[0126] Optionally, the adjustment module 3 is further configured to adjust the active pixel sensor 100 into a second working mode when the current light intensity is greater than the predetermined light intensity.

[0127] The control module 4 is also used to cancel the application of a high-voltage pulse signal to the photocathode of the active pixel sensor 100.

[0128] like Figure 8 As shown, the active pixel sensor 100 of this application embodiment includes a detection module 1, a comparison module 2, an adjustment module 3, and a control module 4. Based on the cooperation of the above modules, the active pixel sensor 100 of this application embodiment can change the low-level duration of the high-voltage pulse signal in the subsequent frame period by delay control, thereby changing the amount of electrons excited by the photocathode when irradiated by light, and the amount of electrons accelerated by the high-voltage electric field formed between the photocathode and the pixel device layer, thereby adjusting the total amount of electrons hitting the pixel device layer, and thus changing the detection capability of the active pixel sensor 100 in weak light in nighttime environments, facilitating imaging of the active pixel sensor 100 in low-light environments.

[0129] According to a third aspect of this application, an electronic device is provided, which includes the aforementioned active pixel sensor and incorporates all the technical effects of the aforementioned active pixel sensor.

[0130] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0131] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A control method for an active pixel sensor used in a rolling shutter, characterized in that, include: Step S101: Repeat the detection of the current light intensity according to the detection cycle; Step S102: Compare the current light intensity with the predetermined light intensity; Step S201: If the current light intensity is less than the predetermined light intensity, the active pixel sensor is adjusted to enter the first working mode. Step S202: Based on the current light intensity, apply a high-voltage pulse signal of a predetermined period to the photocathode of the active pixel sensor in subsequent frame cycles, and control the low-level duration of the high-voltage pulse signal. Each frame cycle includes multiple sequential exposure intervals, and the low-level duration of the high-voltage pulse signal in the current frame cycle remains unchanged.

2. The control method according to claim 1, characterized in that, The duration of the exposure interval is Q times the predetermined period, where Q is an integer from 1 to 10.

3. The control method according to claim 1, characterized in that, Each predetermined cycle includes a pulse interval in which a high-voltage pulse signal is applied; The pulse interval is configured within the exposure interval, and the duration of the pulse interval is less than or equal to the duration of the exposure interval.

4. The control method according to claim 1, characterized in that, The predetermined period is one-P times the frame period of the active pixel sensor, where P is a positive integer greater than 1.

5. The control method according to claim 1, characterized in that, The start time of each frame period is aligned with the rising edge of the exposure signal; within a frame period, the start time of the first predetermined period is aligned with the rising edge of the exposure signal.

6. The control method according to claim 1, characterized in that, Step S202 includes: Based on the current light intensity and light strength standard, obtain the duty cycle of the low-level duration corresponding to the high-voltage pulse signal in the subsequent frame period; The duration of the low level in subsequent frame periods is adjusted according to the duty cycle.

7. The control method according to claim 6, characterized in that, The light intensity standard is represented by grayscale values; Step S202 includes calculating the average gray value of the active pixel sensor in the current frame period.

8. The control method according to claim 7, characterized in that, The average grayscale value is converted into the duty cycle using a preset function, so that the duty cycle is inversely proportional to the average grayscale value.

9. The control method according to claim 6, characterized in that, The duty cycle remains constant within one frame period.

10. The control method according to claim 1, characterized in that, The detection period is N times the frame period, where N is any integer from 1 to 5.

11. The control method according to claim 1, characterized in that, Step S202 includes: starting from the Mth subsequent frame period, applying a high-voltage pulse signal to the photocathode and controlling the low-level duration, where M is any integer from 1 to 5.

12. The control method according to claim 3, characterized in that, Each frame cycle also includes a read interval; The pulse interval and the reading interval partially overlap.

13. The control method according to claim 1, characterized in that, Also includes: Step S301: If the current light intensity is greater than the predetermined light intensity, the active pixel sensor is adjusted to enter the second working mode. Step S302: Cancel the application of the high-voltage pulse signal to the photocathode of the active pixel sensor.

14. The control method according to claim 13, characterized in that, Adjusting the active pixel sensor into the first operating mode includes: adjusting the lens assembly to focus the image on the photocathode; Adjusting the active pixel sensor into a second operating mode includes: adjusting the lens assembly to focus the image on the pixel device layer of the active pixel sensor.

15. An active pixel sensor for a rolling shutter, used to execute the control method according to any one of claims 1 to 14, characterized in that, The active pixel sensor (100) includes: The detection module (1) is used to repeatedly detect the current light intensity according to the detection cycle; Comparison module (2), the comparison module (2) is used to compare the current light intensity with the predetermined light intensity; The adjustment module (3) is used to adjust the active pixel sensor (100) into the first working mode when the current light intensity is less than the predetermined light intensity. The control module (4) is used to apply a high voltage pulse signal of a predetermined period to the photocathode of the active pixel sensor (100) in subsequent frame cycles according to the current light intensity, and to control the low level duration of the high voltage pulse signal. Each frame cycle includes multiple sequential exposure intervals.

16. The active pixel sensor according to claim 15, characterized in that, The adjustment module (3) is also used to adjust the active pixel sensor (100) into a second working mode when the current light intensity is greater than the predetermined light intensity; The control module (4) is also used to cancel the application of a high-voltage pulse signal to the photocathode of the active pixel sensor (100).

17. An electronic device, characterized in that, Includes the active pixel sensor (100) as described in claim 15 or 16.

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