Camera monitoring system display brightness balancing

Abstract

The CMS includes a first camera and a second camera providing a first field of view and a second field of view, respectively. The first display and the second display depict at least a portion of a first field of view and a second field of view. The first display and the second display include a first brightness and a second brightness, respectively. First and second ambient light sensors are proximate to the first and second displays, respectively, and provide first and second light ambient signals indicative of an amount of ambient light in an area of the first and second displays, respectively. The controller is in communication with the first display and the second display, and in communication with the first ambient light sensor and the second ambient light sensor. The controller adjusts the other one of the first brightness and the second brightness of the other one of the first display and the second display based on at least one of the first ambient light signal and the second ambient light signal of the one of the first display and the second display.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 403,010, filed on September 1, 2022. Technical Field

[0003] The present disclosure relates to a camera monitoring system (CMS) for use in a commercial truck or similar vehicle, and in particular to a CMS with display brightness control. Background Art

[0004] Mirror replacement systems and camera systems for supplementing the mirror view are utilized in commercial vehicles to enhance the vehicle operator's ability to see the surrounding environment. A camera monitoring system (CMS) utilizes one or more cameras to provide an enhanced field of view to the vehicle operator. In some examples, the CMS covers a larger field of view than conventional mirrors, or includes views that cannot be fully obtained via conventional mirrors.

[0005] In a typical CMS, a camera arm is arranged on each of the left and right sides of the vehicle to provide Class II and Class IV views. Displays are provided on the A-pillars on the driver and passenger sides to display the field of view of the camera arm on that side, simulating a conventional mirror.

[0006] To ensure that the displays are visible to the driver under various ambient light conditions, each display includes one or more ambient light sensors that are used to adjust the brightness of the display based on the sensor readings of the display. In one example system, each light sensor is used to adjust the backlight level of its corresponding individual display only. Such a system may not function as desired. Summary of the invention

[0007] In an exemplary embodiment, a camera monitoring system includes a plurality of cameras, the plurality of cameras including a first camera and a second camera providing a first field of view and a second field of view, respectively. A plurality of displays include a first display and a second display configured to depict at least a portion of the first field of view and the second field of view, respectively, the first display and the second display including a first brightness and a second brightness, respectively. A plurality of ambient light sensors include a first ambient light sensor and a second ambient light sensor, the first ambient light sensor and the second ambient light sensor being respectively close to the first display and the second display and configured to respectively provide a first light environment signal and a second light environment signal indicating the amount of ambient light in the area of ​​the first display and the second display, respectively. A controller communicates with the first display and the second display, and communicates with the first ambient light sensor and the second ambient light sensor. The controller is configured to adjust the other brightness of the first brightness and the second brightness of the other display of the first display and the second display based at least on one of the first ambient light signal and the second ambient light signal of one of the first display and the second display.

[0008] In a further embodiment of any of the above embodiments, the controller is configured to determine which of the first ambient light signal and the second ambient light signal corresponds to a display of the first display and the second display having a brightness greater than the other display of the first display and the second display. The controller is configured to increase the brightness of the other display of the first display and the second display.

[0009] In a further embodiment of any of the above embodiments, the controller is configured to increase the brightness of the other of the first display and the second display by approximately half of a difference between first brightness and second brightness corresponding to the first ambient light signal and the second ambient light signal, respectively.

[0010] In a further embodiment of any of the above embodiments, the first field of view and the second field of view capture a left side and a right side of the vehicle, respectively. Each of the first field of view and the second field of view includes at least a portion of a Class II and / or Class IV view.

[0011] In a further embodiment of any of the above embodiments, the first display and the second display each include a backlight, and the first brightness and the second brightness are provided by the backlight of the corresponding first display and the second display.

[0012] In a further embodiment of any of the above embodiments, the first display and the second display each include pixels, and the controller is configured to adjust the first brightness and the second brightness by changing pixel intensity of the pixels.

[0013] In a further embodiment of any of the above embodiments, the first ambient light sensor and the second ambient light sensor are integrated into the respective first display and the second display.

[0014] In a further embodiment of any of the above embodiments, the first ambient light sensor and the second ambient light sensor are disposed on a portion of the respective first display and the second display at a location other than a back side of the first display and the second display.

[0015] In a further embodiment of any of the above embodiments, the first display and the second display are respectively mounted on the left A-pillar and the right A-pillar in the vehicle cab.

[0016] In a further embodiment of any of the above embodiments, the controller is disposed in at least one of the first display and the second display.

[0017] In a further embodiment of any of the above embodiments, the controller is disposed at a location external to the first display and the second display.

[0018] In another exemplary embodiment, a method for controlling display brightness in a camera monitoring system includes: detecting first and second ambient light conditions in areas of a first display and a second display arranged in a vehicle cab, respectively; and adjusting the brightness of at least one of the first display and the second display based on both the first ambient light and the second ambient light.

[0019] In a further embodiment of any of the above embodiments, an area of ​​each of the first display and the second display is proximate to an opposing A-pillar.

[0020] In a further embodiment of any of the above embodiments, the detecting step is performed at locations on the first display and the second display.

[0021] In a further embodiment of any of the above embodiments, the method includes the following steps: calculating the first display brightness and the second display brightness based on the first ambient light condition and the second ambient light condition; and determining which of the first display brightness and the second display brightness is greater. The adjusting step includes increasing the brightness of one of the first display and the second display whose brightness is darker than the other of the first display brightness and the second display brightness.

[0022] In a further embodiment of any of the above embodiments, the brightness of the dimmer display is increased by half the difference between the first ambient light and the second ambient light.

[0023] In a further embodiment of any of the above embodiments, the brighter display among the first display and the second display is not adjusted.

[0024] In a further embodiment of any of the above embodiments, the adjusting step is performed based on a preset cab illumination value.

[0025] In a further embodiment of any of the above embodiments, the calculating step is performed based on a configurable lookup table.

[0026] In a further embodiment of any of the above embodiments, the method includes filtering jitter of the first signal and the second signal from the first ambient light sensor and the second ambient light sensor, respectively.

[0027] In a further embodiment of any of the above embodiments, the method includes filtering spikes of the first signal and the second signal from the first ambient light sensor and the second ambient light sensor, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present disclosure may be further understood by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

[0029] Figure 1A is a schematic front view of a commercial truck having a camera monitoring system (CMS) for providing at least Class II and Class IV views.

[0030] Figure 1B is a schematic top view of a commercial truck with a camera monitoring system providing Class II, Class IV, Class V, and Class VI views.

[0031] Figure 2A is a schematic top view of a vehicle cab including a display.

[0032] Figure 2B is a perspective view of an example display according to the disclosed camera monitoring system (CMS).

[0033] Figure 3 is a flow chart illustrating a method of controlling display brightness in a CMS.

[0034] Figure 4 is a graph showing a spike filter in a CMS with display brightness control, where the Y-axis is lux and the X-axis is sample number.

[0035] Figure 5 is a graph showing a dither filter in a CMS with display brightness control, where the Y-axis is lux and the X-axis is sample number.

[0036] The embodiments, examples and alternatives of the preceding paragraphs, claims or the following description and drawings, including any of their various aspects or corresponding individual features, may be adopted independently or in any combination. Features described in conjunction with one embodiment are applicable to all embodiments unless these features are incompatible. The same reference numerals and numbers in the various drawings represent the same elements. DETAILED DESCRIPTION

[0037] A schematic diagram of a commercial vehicle 10 is shown in Figure 1A and Figure 1B 1. The vehicle 10 includes a vehicle cab or tractor 12 for towing a trailer 14. It should be understood that the vehicle cab 12 and / or trailer 14 may be of any configuration. Although commercial trucks are contemplated in the present disclosure, the present invention may also be applied to other types of vehicles. The vehicle 10 includes a camera monitoring system (CMS) 15 ( Figure 2A ), the CMS 15 has a driver-side camera arm 16a and a passenger-side camera arm 16b mounted to the exterior of the vehicle cab 12. If desired, the camera arms 16a, 16b may also include conventional mirrors integrated therewith, although in some examples the CMS 15 may be used to completely replace the mirrors. In other examples, each side may include multiple camera arms, each arm housing one or more cameras and / or mirrors.

[0038] Each of the camera arms 16a, 16b includes a base fixed to, for example, the cab 12. The pivot arm is supported by the base and can be articulated relative to the base. At least one rear-facing camera 20a, 20b is disposed within the camera arms 16a, 16b, respectively. The external cameras 20a, 20b provide an external field of view FOV, respectively. EX1 FOV EX2 , each field of view includes at least one of a Class II and a Class IV view ( Figure 1B ), which are legally required views in the commercial trucking industry. The Class II view for a given side of the vehicle 10 is a subset of the Class IV view for the same side of the vehicle 10. If desired, multiple cameras may also be used in each camera arm 16a, 16b to provide these views. For example, Class II and Class IV views are defined in European R46 legislation, and the United States and other countries have similar driving visibility requirements for commercial trucks. Any reference to "class" views is not intended to be limiting, but rather is intended as an example of the type of view provided to the display by a particular camera. Each arm 16a, 16b may also provide a housing that encloses electronic devices (e.g., a controller) configured to provide various features of the CMS 15.

[0039] A first video display 18a and a second video display 18b are arranged on each of the driver side and the passenger side within the vehicle cab 12, on or near the A-pillars 19a, 19b (collectively referred to as the A-pillars 19), to display Level II and Level IV views on the corresponding sides of the vehicle 10, which provide rearward-facing side views along the vehicle 10 captured by the external cameras 20a, 20b.

[0040] If video of Class V and / or Class VI views is also desired, camera housing 16c and camera 20c may be disposed at or near the front of vehicle 10 to provide those views ( Figure 1B ). A third display 18c disposed within the cab 12 near the top center, left, or right side of the windshield may be used to display to the driver Class V and Class VI views toward the front of the vehicle 10. The displays 18a, 18b, 18c (collectively, displays 18) face a driver area 24 within the cab 22 where an operator sits in a driver's seat 26. The location, size, and field of view streamed to any particular display may vary from the configuration described in this disclosure and still incorporate the disclosed invention.

[0041] If video of a Class VIII view is desired, camera housings may be provided on the sides and rear of the vehicle 10 to provide a field of view that includes some or all of the Class VIII area of ​​the vehicle 10. In such an example, the third display 18c may include one or more frames that display a Class VIII view. Alternatively, an additional display may be added near the first display 18a, the second display 18b, and the third display 18c and provide a display dedicated to providing a Class VIII view.

[0042] refer to Figure 2A and Figure 2B Each display 18a, 18b (and possibly other displays if desired) includes a housing 32 that is mounted to its corresponding A-pillar 19, or integrated into the vehicle trim, for example, by a bracket 33. A screen 34 is mounted on the front of the housing 32 facing the driver. The screen 34 can be any suitable screen, such as a TFT, LCD, LED, OLED, etc. Each type of screen typically uses some method to adjust the perceived brightness. For example, if each display 18 is an LCD, the screen will typically include a backlight 36 that can be adjusted to make the screen 34 more visible to the driver under various ambient light conditions. Compared to bright ambient lighting conditions, low ambient lighting conditions use relatively less backlight.

[0043] To provide automatic adjustment of display brightness, each display 18a, 18b includes a first ambient light sensor 28a and a second ambient light sensor 28b (collectively referred to as ambient light sensors 28) configured to sense the amount of ambient light in the area surrounding the display. The ambient light sensors 28 are arranged to detect light in the environment surrounding the display 18. Ambient light conditions (such as bright sunlight) may make it difficult for the driver to view images on one or both displays 18. For example, in an LCD display, the brightness of the display 18 uses a backlight 36. As will be understood below, other display adjustments are possible. The ambient light sensor 28 can be mounted on the A-pillar, the dashboard, or other locations; however, the ambient light sensor 28 is arranged on the front of the housing 32 so that the A-pillar does not block the light that shines on the ambient light sensor 28, which should be closest to the ambient light near the screen 34. Although only one ambient light sensor 28 is shown for each display 18, more ambient light sensors can be used if desired.

[0044] The disclosed CMS 15 operates to improve display visibility for the driver under different ambient lighting conditions. Typically, digital rear-view (or front or side) displays adjust brightness levels individually based on light sensors that measure ambient light. However, when light comes from one side of the vehicle, such as a low setting sun, automatic brightness adjustment for each display based on its separate independent ambient light sensor may not provide satisfactory brightness adjustment for multiple CMS displays. For example, bright sunlight from one side may cause one monitor to receive a lot of light, resulting in an automatic high brightness adjustment for that display (as expected), but the other display ambient light sensors may be in the shadow, resulting in low brightness levels. Since the driver's eyes are adjusting to the ambient light inside and outside the cabin, this darker monitor also needs to be bright, so this can be a problem for the driver. When one or more displays are too dim, this makes it more difficult for the driver to see important information in any dark display, such as other cars, people, bicycles, etc.

[0045] A variety of display elements, such as contrast, brightness (intensity of individual pixels), and backlight can be used to adjust the overall brightness of the displayed image on the screen. In the example CMS 15, if an LCD screen is used, the backlight 36 is used to adjust the display brightness for given ambient light conditions. Likewise, it should be understood that other techniques can be used to provide and adjust brightness. Based on the ambient light sensor signal in the area of ​​the display 18, a typical brightness setting can be represented according to the following table.

[0046] Table 1

[0047]

[0048] brightness(%)

[0049] If optionally set in a particular system, the "offset %" corresponds to a preset cab illumination value for a cab with user-adjustable interior cab lighting (e.g., instrument cluster brightness, switch / user interface brightness, etc.). For example, older vehicles utilize a rheostat to adjust the interior cab lighting brightness, and newer vehicles typically provide this adjustability digitally via a settings menu in, for example, an infotainment system. In the example shown in Table 1, five "brightness curves" (0%, 25%, 50%, 75%, 100%) are provided. This allows the driver to select a display with an overall brighter or darker display based on the brightness preference selected by the driver. For example, if a 50% offset is selected as the preset cab lighting value (i.e., the interior cab brightness is dimmed by half), the display brightness is selected based on the display brightness value in the offset row (either the left or right side within the row). Therefore, an ambient light sensor for a given display that detects 10 lux with a 50% offset will provide the display with an initial display brightness of 50% intensity. Depending on the configuration, this optional offset can be added to a single display or all displays. Of course, it is possible to use only one setting (ie without reference to the cabin lighting) and thus provide no offset.

[0050] The above Table 1 values ​​are interpolated as needed based on the sensed ambient light and the selected offset (if applicable, as the offset is optional). The 0.1 lux point defines the brightness at night. The range of 0 to 1 lux (or, for example, 0 to 0.1 lux) is the brightness applied during dusk / dawn conditions, which depends on many aspects such as the selected sensor, tinted glass attenuation, and sampling. The disclosed brightness adjustment method applies to the entire range of ambient light conditions.

[0051] refer to Figure 3 , a method 100 for controlling display brightness in a CMS 15 includes detecting first and second ambient lights in the areas of a first display 18a and a second display 18b, respectively (block 102). In one example method of operation, each update cycle, the controller calculates an initial display brightness based on the detected ambient light and an offset using a configurable brightness table (Table 1) (block 104). Once the initial brightness of each display has been calculated (i.e., the initial brightness of each monitor determined based on the ambient light sensed values ​​of Table 1), the controller determines which display has an initial maximum brightness (block 106). In order to balance the display brightness, the brightness of the darker monitor is "boosted". If the initial display brightness values ​​are the same, the difference will simply be equal to zero and no balancing will occur. It should be understood that the above method can be used to balance monitor brightness in a system with more than two monitors.

[0052] As described above, if the calculated initial brightnesses are different from each other, then the brightness of at least one display is adjusted based on the comparison (block 108). For example, the adjustment may be performed by increasing the brightness of the darker display.

[0053] The above method is an example of first using the calculated display brightness to perform brightness balance. To achieve the same function, the detected first ambient light and second ambient light may be directly used to determine the brightest display and the required display brightness adjustment (ie, step 104 may be omitted).

[0054] For example, sensed ambient light below 1 lux corresponds to dark / dusk / dawn ambient light conditions, which typically require better display adjustment, which is achieved by comparing the ambient light readings from the ambient light sensors 28a, 28b of the two displays 18a, 18b. To overcome the problem of one of the displays 18 being too dim during low light conditions, the brightness of the displays 18a, 18b is balanced. In one example, the display brightness balancing algorithm (Equation 1) checks which display is the brightest and then adjusts the darker display (increases the brightness by half the difference) according to the following equation:

[0055] BRT_NEW=BRT_OLD+(BRT_MAX-BRT_OLD) / 2 (Formula 1).

[0056] in:

[0057] BRT_NEW is the new calculated brightness % for the darker display

[0058] BRT_OLD is the brightness % of the darker display before adjustment and based on the ambient light sensor associated with the darker display, and

[0059] BRT_MAX is the brightness % of the brighter display based on the ambient light sensor associated with the brighter display.

[0060] Embodiment 1:

[0061] According to Table 1, when the driver ambient light sensor senses 2 lux, the driver display brightness is 20%.

[0062] According to Table 1, when the driver ambient light sensor senses <2 lux, the passenger display brightness is 16%.

[0063] According to Formula 1, in the case of <2 lux, the passenger display is adjusted to 18% brightness, that is, 16% + (20% - 16%) / 2 = 18％ .

[0064] Embodiment 2:

[0065] According to Table 1, when the driver ambient light sensor senses 1 lux, the driver display brightness is 16%.

[0066] According to Table 1, in the case where the driver ambient light sensor senses <1 lux, the passenger display brightness is 8%.

[0067] According to Formula 1, when <1 lux, the passenger display is adjusted to 12% brightness, that is, 8% + (16% – 8%) / 2 = 12％ .

[0068] In the above example, the display with the larger initial brightness is not adjusted, and the brightness of the darker display is increased by half the difference in initial brightness between the first display 18a and the second display 18b. With the above implementation, not only is performance during low light conditions improved, but the brightness of the two displays is more uniform for the driver's viewing angle, which is valuable in strong directional light (e.g., during sunrise or sunset).

[0069] Brightness balancing is performed only when all ambient light sensors are working correctly and there is no other inhibition. Centralized and decentralized processing configurations can be used to perform the disclosed method. For example, the controller 30 is set in at least one of the first display 18a and the second display 18b, that is, in one display, or in both displays. In another example, the controller 30 is set at a position outside the first display 18a and the second display 18b (that is, arranged away from the first display 18a and the second display 18b).

[0070] Due to the steep gradients between collocation points and flickering issues, additional filtering is achieved by using spike filters and / or jitter filters, e.g. Figure 4 and Figure 5 shown.

[0071] Spike Filter( Figure 4 ) will filter input signal changes that are equal to or greater than three times the previous sample, so if a new sample is three times larger or three times smaller (less than 1 / 3 of the old sample) than the old sample, it will be filtered out. In one example, the spike filter is allowed to filter only 2 samples (200ms) per 2 second moving window (timeout) starting after the first filtered sample. Since the filtering is done in real time, rather than retrospectively, this restriction needs to be added so that the entire rising or falling slope is not filtered out. The number of allowed samples to be filtered is selected so that no delay is introduced when reacting to brightness changes, thereby meeting the performance requirements.

[0072] For the dither filter ( Figure 5), a new input value is only used if it is at least three times greater or three times less than the previous sample (less than 1 / 3 of the old sample). This filtering will distinguish fluctuations in the input signal. For example, during nighttime lighting conditions, if the new value equals or exceeds 2-4 lux, the new value will be used.

[0073] As described above, the controller 30 ("controller" may be generally referred to as "30") communicates with the first display 18a and the second display 18b and communicates with the first ambient light sensor 28a and the second ambient light sensor 28b. The controller 30 is configured to calculate and compare the first display brightness and the second display brightness, respectively, and is configured to adjust at least one of the first brightness and the second brightness of the display 18 based on the disclosed method to improve the visibility of the driver.

[0074] It should be noted that the described controller 30 may be used to implement various functions disclosed in this application. The controller 30 may include one or more discrete units.

[0075] In terms of hardware architecture, such a computing device may include a processor, a memory, and one or more input and / or output (I / O) device interfaces communicatively coupled via a local interface. The local interface may include, for example, but not limited to, one or more buses and / or other wired or wireless connections. The local interface may have additional elements omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers to enable communication. In addition, the local interface may include address, control, and / or data connections to enable appropriate communication between the above components.

[0076] The controller 30 may be a hardware device for executing software, particularly software stored in a memory. The controller 30 may be a custom or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the controller, a semiconductor-based microprocessor (in the form of a microchip or chipset), or any device generally used to execute software instructions.

[0077] The memory may include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, VRAM, etc.) and / or non-volatile memory elements (e.g., ROM, hard drive, tape, CD-ROM, etc.). In addition, the memory may contain electronic, magnetic, optical and / or other types of storage media. The memory may also have a distributed architecture in which various components are remote from each other but can be accessed by the processor.

[0078] The software in the memory may include one or more separate programs, each of which includes an ordered list of executable instructions for implementing logical functions. System components embodied as software may also be interpreted as source programs, executable programs (object code), scripts, or any other entity including a set of instructions to be executed. When constructed as a source program, the program is translated via a compiler, assembler, interpreter, etc., which may or may not be included in the memory.

[0079] The disclosed input and output devices that can be coupled to the system I / O interface can include input devices such as, but not limited to, keyboards, mice, scanners, microphones, cameras, mobile devices, proximity devices, etc. In addition, output devices such as, but not limited to, printers, displays, etc. Finally, input and output devices can also include devices that communicate as input and output, such as, but not limited to, modulators / demodulators (modems; used to access another device, system, or network), radio frequency (RF) or other transceivers, telephone interfaces, bridges, routers, etc.

[0080] When the controller 30 is in operation, the processor may be configured to execute software stored in the memory, transfer data to and from the memory, and generally control the operation of the computing device according to the software. The software in the memory is read in whole or in part by the processor, possibly cached within the processor, and then executed.

[0081] Each loop determines the individual brightness of each display (e.g., according to Table 1), after which an adjustment function is performed to increase the brightness of the darker display. The brightness "boost" in the disclosed example is set to half the difference, but need not be limited to half. This method works for all values ​​between 0% and 100%, but at low % values, the positive effect may be limited.

[0082] The association / correlation of display brightness levels between multiple displays ensures that the displays work together to adjust brightness levels. The method can be performed with two displays, three displays, four displays, or more. The display brightness integration between multiple displays helps the driver see important information during sunset or sunrise sunlight conditions when light is coming from the side of the vehicle to prevent one or more displays from being too dim as with typical systems.

[0083] It should also be understood that although a specific component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit from this. Although a specific order of steps is shown, described, and claimed, it should be understood that unless otherwise indicated, the steps may be performed in any order, separated, or combined, and will still benefit from the present invention.

[0084] Although the different examples have specific components shown in the drawings, embodiments of the present invention are not limited to those specific combinations. Some components or features from one example may be used in combination with features or components from another example.

[0085] Although example embodiments have been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of the claims. For that reason, the following claims should be studied to determine their true scope and content.

Claims

1. A camera monitoring system, comprising: a plurality of cameras, including a first camera and a second camera providing a first field of view and a second field of view, respectively; a plurality of displays, including a first display and a second display configured to depict at least portions of the first field of view and the second field of view, respectively, the first display and the second display comprising a first brightness and a second brightness, respectively; a plurality of ambient light sensors including a first ambient light sensor and a second ambient light sensor, the first ambient light sensor and the second ambient light sensor being proximate to the first display and the second display, respectively, and configured to provide first light ambient signals and second light ambient signals, respectively, indicative of an amount of ambient light in an area of ​​the first display and the second display, respectively; as well as A controller is provided, the controller communicating with the first display and the second display and communicating with the first ambient light sensor and the second ambient light sensor, the controller being configured to adjust the other of the first brightness and the second brightness of the other of the first display and the second display based on at least one of the first ambient light signal and the second ambient light signal of one of the first display and the second display.

2. The system according to claim 1, wherein: The controller is configured to determine which of the first ambient light signal and the second ambient light signal corresponds to the one of the first display and the second display having a higher brightness, and the controller is configured to increase the brightness of another display other than the one of the first display and the second display having a higher brightness.

3. The system according to claim 2, wherein: The controller is configured to increase brightness of the other of the first display and the second display by approximately half of a difference between the first brightness and the second brightness corresponding to the first ambient light signal and the second ambient light signal, respectively.

4. A system according to any preceding claim, wherein: The first field of view and the second field of view capture a left side and a right side of the vehicle, respectively, and each of the first field of view and the second field of view includes at least a portion of a Class II and / or Class IV view.

5. A system according to any preceding claim, wherein: The first display and the second display each include a backlight, and the first brightness and the second brightness are provided by the backlight of the corresponding first display and second display.

6. A system according to any preceding claim, wherein: The first display and the second display each include pixels, and the controller is configured to adjust the first brightness and the second brightness by changing pixel intensities of the pixels.

7. A system according to any preceding claim, wherein: The first ambient light sensor and the second ambient light sensor are integrated into respective first and second displays.

8. The system according to claim 7, wherein: The first ambient light sensor and the second ambient light sensor are disposed on a portion of the respective first display and the second display at a position other than the back side of the first display and the second display.

9. The system according to claim 7 or 8, wherein: The first display and the second display are respectively mounted on a left A-pillar and a right A-pillar in a vehicle cab.

10. A system according to any preceding claim, wherein: The controller is provided in at least one of the first display and the second display.

11. A system according to any preceding claim, wherein: The controller is disposed at a location outside the first display and the second display.

12. A method for controlling display brightness in a camera monitoring system, the method comprising: detecting first and second ambient light conditions in the area of ​​a first display and a second display disposed in the cab, respectively; as well as A brightness of at least one of the first display and the second display is adjusted based on both the first ambient light and the second ambient light.

13. The method according to claim 12, wherein: The area of ​​each of the first display and the second display is proximate to an opposing A-pillar.

14. The method according to claim 13, wherein: The detecting step is performed at locations on the first display and the second display.

15. The method according to any one of claims 12 to 14, comprising the steps of: calculating a first display brightness and a second display brightness based on the first ambient light condition and the second ambient light condition, and determining which of the first display brightness and the second display brightness is higher; and Wherein, the adjusting step includes: increasing the brightness of the display with darker brightness between the first display and the second display.

16. The method according to claim 15, wherein: The brightness of the display with the dimmer brightness is increased by half the difference between the first ambient light and the second ambient light.

17. The method according to claim 15 or 16, wherein: The display with brighter brightness among the first display and the second display is not adjusted.

18. The method according to any one of claims 15 to 17, wherein: The calculating step is performed based on a configurable look-up table.

19. The method according to any one of claims 12 to 18, wherein: The adjusting step is performed based on a preset cabin lighting value.

20. A method according to any one of claims 12 to 19, comprising: Jitter is filtered from first and second signals from the first and second ambient light sensors, respectively.

21. A method according to any one of claims 12 to 20, comprising: Spikes of the first signal and the second signal from the first ambient light sensor and the second ambient light sensor, respectively, are filtered.

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