Image generation unit, head-up display device and monitoring method

Abstract

The present disclosure relates to an image generation unit, a head-up display device, and a monitoring method. In one aspect, an image generation unit is provided, including: a display panel; a light sensor, arranged on the light-incoming side of the display panel, for sensing the intensity of light toward the display panel; and a monitoring device, configured to: obtain a first intensity sensed by the light sensor when there is no backflow of sunlight; when there is backflow of sunlight, obtain a second intensity sensed by the light sensor, and obtain a third intensity sensed by the light sensor by assigning a non-zero grayscale value to the background of the image while the user interface of the image displayed by the display panel remains unchanged; and determine a fourth intensity of light incident on the display panel from the light-outgoing side of the display panel based on the first intensity, the second intensity, and the third intensity. In this way, the intensity of the backflowing sunlight can be accurately determined, and the internal structure of the head-up display device can be simplified.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular, to an image generation unit, a head-up display device, and a monitoring method. Background Art

[0002] Head Up Display (HUD) devices are widely used in vehicles and other transportation vehicles. They are used to display information such as vehicle conditions on the windshield of the vehicle, etc., so that the driver can obtain this information while maintaining continuous attention to road conditions.

[0003] Due to the light transmittance of the windshield, external sunlight will enter the HUD device through the windshield, and will reach and enter the display panel of the picture generation unit (PGU) along the reverse path of the display light of the HUD device. This phenomenon is usually called sunlight backflow. The energy of the sunlight backflowing into the display panel will be absorbed by the display panel and thus the temperature of the display panel will rise rapidly, which may cause damage to the display panel.

[0004] At present, the presence of sunlight backflow and the intensity of the backflowing sunlight are determined by using a temperature sensor to detect the temperature of the PGU. However, usually, the temperature sensor is set away from the display panel of the PGU, resulting in the measured temperature not being able to accurately reflect the actual temperature of the display panel, thus affecting the determination result. On the other hand, if the temperature sensor is directly set on the display panel, an additional connection structure is required, which will not only complicate the internal structure of the HUD device, but may also interfere with the display light emitted from the display panel. Summary of the invention

[0005] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0006] An object of the present disclosure is to provide a PGU that can accurately determine the intensity of backflowing sunlight.

[0007] Another object of the present disclosure is to provide a PGU that can simplify the internal structure of a HUD device.

[0008] In order to achieve the above objective, according to one aspect of the present disclosure, a PGU is provided, comprising:

[0009] Display panel;

[0010] a light sensor, disposed on the light-incoming side of the display panel, for sensing the intensity of light toward the display panel; and

[0011] The monitoring device is configured to: obtain a first intensity sensed by the light sensor when there is no sunlight backflow in the PGU; obtain a second intensity sensed by the light sensor when there is sunlight backflow in the PGU, and obtain a third intensity sensed by the light sensor by assigning a non-zero grayscale value to the background of the image while the user interface of the image displayed on the display panel remains unchanged; and determine a fourth intensity of light incident on the display panel from a light output side of the display panel opposite to a light input side based on the first intensity, the second intensity and the third intensity.

[0012] In some embodiments, the monitoring device can be configured to determine a fourth intensity based on a first intensity, a second intensity, a third intensity, a first coefficient, and a second coefficient, wherein the first coefficient is a ratio of a transmittance of the user interface when it is white to an actual transmittance of the user interface, and the second coefficient is a ratio of a transmittance of the background when it is white to an actual transmittance of the background.

[0013] In some embodiments, the actual transmittance of the user interface can be the transmittance of the user interface when it is white, or the actual transmittance of the user interface can be determined based on the number of pixels used to display the user interface and the color gradation value corresponding to each pixel in the pixels used.

[0014] In some implementations, the actual transmittance of the background may be determined according to the color scale values ​​corresponding to the pixels of the background.

[0015] In some embodiments, the monitoring device can be configured to determine the fourth intensity based on the first intensity, the second intensity, the third intensity, the first coefficient, the second coefficient, the number of pixels in the area covered by the light spot formed by the backflow of sunlight on the display panel, and the transmittance of the pixels of the image when it is white.

[0016] In some embodiments, the monitoring device may be configured to obtain the number of pixels of the area covered by the light spot through light path simulation.

[0017] In some embodiments, the monitoring device may be configured to determine whether sunlight backflow occurs in the PGU, and obtain a first intensity when it is determined that sunlight backflow does not occur, and obtain a second intensity and a third intensity when it is determined that sunlight backflow occurs.

[0018] In some embodiments, the determination may be made based on the intensity sensed by the light sensor, or may be made based on the angle of the sun's rays.

[0019] In some implementations, the background may be assigned a grayscale value that is smaller than the grayscale value of the user interface so that the background is invisible.

[0020] In some embodiments, the monitoring device may be configured to output a protection strategy according to the fourth intensity and a corresponding duration of the light irradiating the display panel.

[0021] According to another aspect of the present disclosure, a HUD device is also provided, which includes the PGU described in any of the above embodiments.

[0022] According to another aspect of the present disclosure, a monitoring method is further provided. The monitoring method is applicable to the following PGU, wherein the PGU includes a display panel and a light sensor, wherein the light sensor is arranged on a light-incoming side of the display panel to sense the intensity of light toward the display panel, and the monitoring method includes:

[0023] Acquire a first intensity sensed by the light sensor when there is no sunlight backflow in the PGU;

[0024] When sunlight backflow exists in the PGU, a second intensity sensed by the light sensor is obtained, and a third intensity sensed by the light sensor is obtained by assigning a non-zero gray value to the background of the image without changing the user interface of the image displayed by the display panel; and

[0025] A fourth intensity of the light incident on the display panel from a light exiting side of the display panel opposite to the light entering side is determined according to the first intensity, the second intensity, and the third intensity.

[0026] In some embodiments, determining a fourth intensity of light incident on the display panel from a light exiting side of the display panel opposite to the light entering side according to the first intensity, the second intensity, and the third intensity may include:

[0027] The fourth intensity is determined according to the first intensity, the second intensity, the third intensity, the first coefficient and the second coefficient, wherein the first coefficient is the ratio of the transmittance of the user interface when it is white to the actual transmittance of the user interface, and the second coefficient is the ratio of the transmittance of the background when it is white to the actual transmittance of the background.

[0028] In some implementations, determining the fourth strength according to the first strength, the second strength, the third strength, the first coefficient, and the second coefficient may include:

[0029] The fourth intensity is determined according to the first intensity, the second intensity, the third intensity, the first coefficient, the second coefficient, the number of pixels in the area covered by the light spot formed by the backflow of sunlight on the display panel, and the transmittance of the pixels of the image when it is white.

[0030] According to the above technical solution, by setting a light sensor on the light-incoming side of the display panel, the intensity of the sunlight irradiating on the display panel can be determined, and the internal structure of the HUD device can be simplified. In addition, by obtaining the intensity sensed by the light sensor in the case of no sunlight backflow, in the case of sunlight backflow, and in the case of sunlight backflow, the user interface remains unchanged and the background is assigned a non-zero grayscale value, the intensity of the light irradiating on the display panel can be accurately determined without obtaining the intensity of the reflected light formed by the reflection of the light emitted by the LED. In this way, the influence of the attenuation of the luminous efficiency of the LED on the detection accuracy of the intensity of the sunlight irradiating on the display panel can be eliminated, and there is no need to calibrate each device individually, which saves costs and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The features and advantages of the embodiments of the present disclosure will become more easily understood through the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be exaggerated or reduced to show details of particular components.

[0032] In the attached picture:

[0033] Figure 1 A schematic diagram showing the backflow of external sunlight into the PGU of a HUD device in the related art.

[0034] Figure 2 It is a schematic diagram of the structure of a PGU according to an embodiment of the present disclosure.

[0035] Figure 3 It is a schematic diagram of the structure of a PGU equipped with a light distribution element.

[0036] Figure 4 A schematic diagram of an exemplary image displayed by a display panel.

[0037] Figure 5 FIG. 1 is a schematic diagram showing an area covered by a light spot formed by sunlight backflowing onto a display panel.

[0038] Figure 6 FIG. 1 is a schematic diagram showing the light in the PGU 10 when there is no sunlight backflow.

[0039] Figure 7 Schematic diagram showing the light in PGU10 when there is sunlight backflow and the gray value of the background of the image is zero.

[0040] Figure 8 Schematic diagram showing the light in PGU10 when there is sunlight backflow and the gray value of the background of the image is not zero.

[0041] Fig. 9It is a schematic structural diagram of a HUD device according to an embodiment of the present disclosure.

[0042] Fig.10 The present invention is a flowchart of a monitoring method according to an embodiment of the present invention.

[0043] In the drawings, the same or corresponding technical features or components are represented by the same or corresponding reference numerals. DETAILED DESCRIPTION

[0044] The present disclosure is described in detail below with reference to the accompanying drawings by means of exemplary embodiments. It should be noted that the following detailed description of the present disclosure is only for illustrative purposes and is by no means a limitation of the present disclosure.

[0045] It should be noted that, for the sake of clarity, not all features of a specific implementation are described and illustrated in the specification and drawings. Furthermore, in order to avoid unnecessary details that obscure the technical solution that the present disclosure focuses on, only the device structure closely related to the technical solution of the present disclosure is described and illustrated in the specification and drawings, while other details that are not closely related to the technical content of the present disclosure and are known to those skilled in the art are omitted.

[0046] Reference Figure 1 In the related art, the HUD device 1' generally includes a PGU 10' (schematically shown in a dotted frame), a first reflector 20' and a second reflector 30'. The PGU 10' emits a display light S' carrying information such as vehicle conditions toward the first reflector 20', and the display light S' is reflected by the first reflector 20' to the second reflector 30', and then reflected by the second reflector 30' to the windshield 2', and finally reflected by the windshield 2' to the eye box 3', thereby, on the outside of the windshield 2' (i.e., Figure 1 The eye box 3' refers to the range within which the eyes of a user (e.g., a driver) can move in a certain space while keeping the image clear and complete.

[0047] As mentioned above, due to the light transmittance of the windshield 2', the external sunlight 5' will enter the HUD device 1' through the windshield 2' and will basically follow the reverse path of the outgoing path of the display light S' ( Figure 1 The liquid propagates (also called backflow) to PGU10' and enters PGU10'. Figure 1As shown in FIG, PGU 10' includes a display panel 11' and a backlight device 12' for providing backlight to the display panel 11'. In the case of the above-mentioned sunlight backflow, the display panel 11' of PGU 10' will heat up rapidly due to the radiant heat brought by the sunlight backflowing thereon, and thus may be thermally damaged.

[0048] Although the temperature of PGU10' is currently detected by using a temperature sensor to determine whether there is sunlight backflow and the intensity of the backflowing sunlight, the judgment result is not accurate. This is because the temperature sensor is often set away from the display panel 11' of PGU10'. For example, the temperature sensor is often set near the exit surface 1'a of the HUD device 1', resulting in the measured temperature being unable to accurately reflect the temperature on the display panel 11' of PGU10', thereby affecting the accuracy of the judgment result on sunlight backflow obtained based on the measured temperature. However, if the temperature sensor is directly set on the display panel 11', although the temperature of the display panel 11' can be detected, it is often necessary to set an additional connection structure for making the temperature sensor close to the display panel. The connection structure will occupy the internal space of the HUD device 1' to a certain extent, which will not only make the internal structure of the HUD device 1' complicated and affect the flexibility of the design, but may also interfere with the display light S' emitted from the display panel 11', affecting the quality of the displayed image.

[0049] This problem can be solved by the PGU according to the embodiments of the present disclosure.

[0050] First, refer to Figure 2 and Figure 3 , which shows an exemplary internal structure of a PGU 10 according to an embodiment of the present disclosure. Similar to the structure of a PGU 10 ′ in the related art, the PGU 10 also includes a display panel 11 and a backlight device 12 .

[0051] Specifically, the display panel 11 is used to allow the light provided by the backlight device 12 to pass therethrough to form display light S carrying information such as vehicle conditions, and the display panel 11 can be, for example, a liquid crystal display (LCD), a diffusion screen, etc.

[0052] The backlight device 12 is disposed on the light incident side 11 a of the display panel 11 to provide backlight, ie, first light S1 , to the display panel 11 . The backlight device 12 may include a circuit board 121 and a light emitting diode (LED) 122 connected to the circuit board 121 .

[0053] LED 122 can be, for example, Figure 3The LED lamp beads are shown in the form of LED lamp beads. A plurality of LED lamp beads are dispersedly arranged on the circuit board 121 to emit the first light S1 toward the display panel 11. By connecting the LED 122 to the circuit board 121, not only can the LED 122 be powered via the circuit board 121, but also the excess heat generated by the LED 122 can be discharged via the circuit board 121.

[0054] Here, the light-entering side 11a of the display panel 11 refers to the light-entering side of the display panel 11 with respect to the display light S. In other words, the light-entering side 11a is the side of the display panel 11 inside the PGU10, that is, the inner side. On the other hand, the light-exiting side 11b of the display panel 11 opposite to the light-entering side 11a refers to the side from which the display light S emerges, that is, the side of the display panel 11 outside the PGU10, that is, the outer side. When sunlight backflow occurs, sunlight will be incident on the display panel 11 of the PGU10 from the light-exiting side 11b to form a light spot thereon.

[0055] According to an embodiment of the present disclosure, the PGU 10 further includes a light sensor 13 and a monitoring device (not shown).

[0056] The light sensor 13 is also disposed on the light incident side 11a of the display panel 11, so as to sense the intensity of the light (i.e., the second light S2) toward the display panel 11. That is, the light sensor 13 is arranged to sense the intensity of the light propagating away from the display panel 11. Specifically, the light sensor 13 can convert the light signal incident thereon into an electrical signal, and obtain the intensity of the light signal according to the intensity of the electrical signal, such as the magnitude of the current.

[0057] In some examples, such as Figure 3 As shown in , the light sensor 13 can be directly disposed on the circuit board 121 and electrically connected to the circuit board 121 , for example, and a plurality of light sensors 13 can be provided.

[0058] When external sunlight enters the HUD device 1 (in Fig. 9 When the sunlight irradiated on the display panel 11 of the PGU 10 passes through the light-transmitting area on the display panel 11, such as the area with displayed content, and enters the PGU 10, that is, enters the light-incoming side 11a of the display panel 11. Thus, by using the light sensor 13 to sense the intensity of the second light S2 from the light-incoming side 11a, the intensity of the sunlight entering the PGU 10 can be obtained.

[0059] The monitoring device may be configured to determine the intensity of the third light S3 incident on the surface 111 of the display panel 11 on the light exit side 11b according to the intensity of the sensed second light S2. In other words, the intensity of the sunlight irradiated on the display panel 11 may be determined by the monitoring device according to the intensity of the sunlight entering the PGU10 sensed, thereby realizing the detection of sunlight backflow on the display panel 11 of the PGU10.

[0060] In the above embodiment, by setting a light sensor 13 on the light-entering side 11a of the display panel 11 of the PGU10, the light irradiated on the display panel 11 will be sensed by the light sensor 13 in a very short time when entering the PGU10, and because it is the intensity of the light that is sensed, the sensing result will not be affected by the temperature of the backlight device 12, thereby, the intensity of the sunlight irradiated on the display panel 11 can be accurately determined based on the sensing result, and thus it can be accurately determined whether there is sunlight backflow on the display panel 11 of the PGU10. In addition, since the light sensor 13 is set on the light-entering side 11a of the display panel 11, that is, set inside the PGU10, it will not occupy the internal space of the HUD device 1 located outside the PGU10, so that the internal structure of the HUD device 1 will not become complicated, and thus the flexibility of the design will not be affected, and it will not interfere with the display light S emitted from the display panel 11, and thus the quality of the displayed image will not be affected.

[0061] In an embodiment of the present disclosure, the monitoring device is configured to determine the intensity of light incident on the surface 111 of the display panel 11 on the light emitting side 11 b according to the intensity sensed by the light sensor 13 and the intensity of the first light S1 emitted by the backlight device 12 .

[0062] When the HUD device 1 is in operation, the LED 122 is in a lighted state, and the light emitted by the LED 122 is reflected to the light sensor 13 via the surface 112 of the display panel 11 on the light-incoming side 11a. In addition, when the PGU 10 further includes a light distribution element 14 disposed between the display panel 11 and the backlight device 12 for diffusing the light (see Figure 3 ), the light emitted by the LED 122 is also reflected to the light sensor 13 via the optical surface of the light distribution element 14. Therefore, the second light S2 sensed by the light sensor 13 includes the sunlight light that passes through the display panel 11 and enters the light-incoming side 11a and the above-mentioned reflected light, and therefore the intensity of the light sensed by the light sensor 13 includes the intensity of the above-mentioned sunlight light and the intensity of the above-mentioned reflected light.

[0063] In this case, the intensity of the reflected light can be determined based on the intensity of the first light S1 emitted by LED 122, and the intensity of the sunlight light can be obtained by subtracting the intensity of the reflected light from the intensity of the second light S2 sensed by the light sensor 13, thereby determining the intensity of the sunlight irradiated on the display panel 11.

[0064] Typically, the intensity of the first light S1 emitted by LED 122 is determined based on the control signal of LED 122. However, as the use time increases, the luminous efficiency of the LED will decay, resulting in the intensity determined based on the control signal of LED 122 being actually greater than the true intensity of the first light S1, thereby affecting the detection accuracy of the intensity of the sunlight irradiated on the display panel 11. Moreover, in the mass production of HUD devices, there are manufacturing errors, and it is impossible to make the parts of the HUD device completely consistent, resulting in differences in the intensity of the first light S1 determined by the same LED 122 control signal between each device, and the difference may exceed 20%, requiring individual calibration for each device, which is time-consuming and labor-intensive.

[0065] In this regard, refer to Figures 4 to 8 In an embodiment of the present disclosure, the monitoring device is configured to:

[0066] Acquire a first intensity sensed by the light sensor 13 when there is no sunlight backflow into the PGU 10;

[0067] When sunlight backflow exists in the PGU 10, a second intensity sensed by the light sensor 13 is obtained, and a third intensity sensed by the light sensor 13 is obtained by assigning a non-zero gray value to the background 102 of the image 100 while the user interface 101 of the image 100 displayed on the display panel 11 remains unchanged; and

[0068] A fourth intensity of the light incident on the display panel 11 from the light exiting side 11 b of the display panel 11 opposite to the light entering side 11 a is determined according to the first intensity, the second intensity, and the third intensity.

[0069] Specifically, refer to Figure 4 The image 100 displayed by the display panel 11 includes a user interface (UI) 101 and a background 102. The UI is an interface for interaction between a person and a device, and may include text, icons, etc. For example, Figure 4The UI101 therein is the text "Gaoxin Road" and "60 km / h". The UI is usually given a relatively high gray value to make it present a relatively high brightness so that users can clearly observe the information displayed through UI101. Thus, the sunlight rays irradiating on UI101 will pass through it and enter the interior of PGU10. However, for the background 102, usually, the gray value given to it is zero so as not to affect the user's observation of the information displayed by UI101. Thus, the sunlight rays irradiating on the background 102 will not pass through it and enter the interior of PGU10.

[0070] Figure 5 It shows the area 103 (shown by a dashed line) covered by the light spot formed by the backflow of sunlight on the display panel 11. The area 103 is shown to include a part of UI101 and a part of the background 102. In this case, the sunlight rays irradiating on the display panel 11 will pass through the above-mentioned part of UI101 and enter the interior of PGU10, while not passing through the above-mentioned part of the background 102.

[0071] As Figure 6 shown, when there is no backflow of sunlight in PGU10, the second light ray S2 sensed by the light sensor 13 only includes the above-mentioned reflected light ray S2', that is, only includes the reflected light ray formed by the first light ray S1 emitted by the LED122 reflected by the surface 112 of the display panel 11 and the optical surface of the light distribution element 14, and does not include the above-mentioned sunlight rays that backflow onto the display panel 11 and pass through the display panel 11 and enter PGU10. In this case, the first intensity sensed by the light sensor 13 is only the intensity of the above-mentioned reflected light ray S2'.

[0072] As Figure 7 shown, when there is backflow of sunlight in PGU10, the second light ray S2 sensed by the light sensor 13 includes the above-mentioned reflected light ray S2' and the sunlight ray S2" that passes through UI101 and enters the interior of PGU10 (for example, Figure 5 the sunlight ray that passes through the above-mentioned part of UI101 and enters the interior of PGU10). Since the sunlight rays irradiating on the background 102 will not pass through the background 102 and enter the interior of PGU10, therefore, the second light ray S2 does not include this part of the sunlight rays. In this case, the first intensity sensed by the light sensor 13 includes the intensity of the above-mentioned reflected light ray S2' and the intensity of the sunlight ray S2" that passes through UI101 and enters the interior of PGU10.

[0073] As Figure 8As shown in , when the above-mentioned sunlight backflow occurs, the background 102 will be assigned a non-zero grayscale value when the UI 101 remains unchanged, so that the sunlight irradiated on the background 102 can pass through the background 102 and enter the PGU 10, and thus can be sensed by the light sensor 13. At this time, the second light S2 sensed by the light sensor 13 includes the above-mentioned reflected light S2', the sunlight light S2" that passes through the UI 101 and enters the interior of the PGU 10, and the sunlight light S2"' that passes through the background 102 and enters the interior of the PGU 10 (for example, Figure 5 In this case, the first intensity sensed by the light sensor 13 includes the intensity of the above-mentioned reflected light S2', the intensity of the sunlight light S2" that passes through the UI101 and enters the interior of the PGU10, and the intensity of the sunlight light S2"' that passes through the background 102 and enters the interior of the PGU10. Moreover, since the UI101 does not change, the intensity of the sunlight light S2" that passes through the UI101 and enters the interior of the PGU10 is the same as that of the reflected light S2'. Figure 7 In the case shown in FIG, the intensity of the sunlight light S2″ passing through UI 101 and entering the interior of PGU 10 is equal.

[0074] for Figures 6 to 8 The strength relationship involved in can be expressed by the following equations (1) to (3):

[0075] 0*T ui +Q LED =Q0 (1)

[0076] E*T ui +Q LED =Q1 (2)

[0077] E*T ui +E*T b +Q LED =Q2 (3)

[0078] Among them, T ui is the transmittance of UI101 when sunlight backflow occurs (since the transmittance is related to the color level value of UI101 at this time, it is also called the actual transmittance of UI101), T b is the transmittance of the background 102 when sunlight backflow occurs (since the transmittance is related to the color level value of the background 102 at this time, it is also called the actual transmittance of the background 102), E is the intensity of the sunlight irradiated on the display panel 11, that is, the fourth intensity, Q LEDis the intensity of the reflected light, Q0 is the first intensity sensed by the light sensor 13 , Q1 is the second intensity sensed by the light sensor 13 , and Q2 is the third intensity sensed by the light sensor 13 .

[0079] In formula (1), since there is no backflow of sunlight at this time, the intensity of sunlight irradiated on the display panel 11 is zero, and the first intensity Q0 is the intensity Q of the reflected light S2'. LED Here, the intensity of sunlight that passes through the display panel 11 and enters the interior of the PGU 10 is 0*T ui To express.

[0080] In formula (2), although the backflowing sunlight shines on the display panel 11, since the sunlight will not pass through the background 102 and enter the PGU 10, the second intensity Q1 is the intensity Q of the reflected light S2'. LED The sum of the intensity of the sunlight light S2" passing through UI101 and entering the interior of PGU10. Here, the intensity of the sunlight light S2" passing through UI101 and entering the interior of PGU10 is expressed as E*T ui For example, Figure 5 In the case shown in ui is the transmittance of the portion of UI101 located in the region 103, according to the intensity E of the sunlight irradiated on the display panel 11 and the transmittance T ui , you can get the intensity of sunlight S2".

[0081] In formula (3), since sunlight not only passes through UI101, but also passes through background 102 and enters PGU10, the third intensity Q2 is the intensity Q of the reflected light S2'. LED , the sum of the intensity of the sunlight light S2" passing through UI101 and entering the interior of PGU10 and the intensity of the sunlight light S2"' passing through the background 102 and entering the interior of PGU10. Here, the intensity of the sunlight light S2"' passing through the background 102 and entering the interior of PGU10 is expressed as E*T b For example, Figure 5 In the case shown in b is the transmittance of the portion of the background 102 located in the region 103, according to the intensity E of the sunlight irradiated on the display panel 11 and the transmittance T b , you can get the intensity of sunlight S2”’.

[0082] Furthermore, by subtracting equation (2) from equation (1) and subtracting equation (3) from equation (2), and processing the subtracted equations, the following equations (4) and (5) are obtained respectively:

[0083] E*K1*Tui =K1(Q1-Q0) (4)

[0084] E*K2*T b =K2(Q2-Q1) (5)

[0085] After merging, the following formula (6) is obtained:

[0086]

[0087] K1 (also called the first coefficient) is the ratio of the transmittance of UI101 when it is white to the actual transmittance T of UI101. ui K2 (also called the second coefficient) is the ratio of the transmittance of the background 102 when it is white to the actual transmittance T of the background 102. b ratio, and K1 and K2 can be pre-known values.

[0088] That is, K1*T ui is the transmittance of UI101 when it is white, and K2*T b is the transmittance when the background is white. Figure 5 In the case shown in ui +K2*T b This means that the portion of UI 101 in region 103 is white, and the portion of background 102 in region 103 is also white, that is, the entire region 103 is white.

[0089] Thus, the following formula (7) can be obtained:

[0090]

[0091] Wherein, N is the number of pixels in the area 103 covered by the light spot formed by the backflow of sunlight on the display panel 11, some pixels display the UI, and some pixels are the background, and T is the transmittance of the pixels of the image 100 when they are white. N can be a pre-known value, and T can also be a known value, for example, obtained from the factory parameters of the display panel 11.

[0092] In this way, when K1, K2, N and T can be accurately obtained in advance, the fourth intensity E of the light irradiated on the display panel 11 can be determined by only detecting the first intensity Q0, the second intensity Q1 and the third intensity Q2 through the light sensor 13, without obtaining the intensity Q of the reflected light S2'. LED That is, it is not necessary to determine the intensity of the first light S1 emitted by LED122 and thereby determine the intensity Q of the reflected light S2' according to the control signal of LED122. LEDThus, the influence of the attenuation of the luminous efficiency of the LED on the detection accuracy of the intensity of the sunlight irradiated on the display panel 11 can be eliminated, and there is no need to calibrate each device individually, which saves costs and improves production efficiency.

[0093] The method for determining K1 and K2 is described below.

[0094] For K1, it is the transmittance of UI101 when it is white and the actual transmittance T of UI101 ui In one implementation, since the number of pixels of UI101 in the image 100 is usually small and most of them are white, the actual transmittance T of UI101 is ui It can be approximately considered to be equivalent to the transmittance of UI101 when it is white, and thus K1 can be approximately treated as equal to 1.

[0095] In addition, the commonly used display panel is red, green, and blue (RGB), and the brightness of each color can be set to 0 to 255 levels, and the corresponding transmittance has 16.77M (256*256*256) types. In other words, one color scale value corresponds to one transmittance. Therefore, in another implementation, the average color scale value for each pixel can be obtained according to the number of pixels used when displaying UI101 and the color scale value corresponding to each pixel in the pixels used, and the actual transmittance T of UI101 is determined based on the average color scale value. ui Then, the transmittance of UI101 when it is white and the actual transmittance T of UI101 can be used to calculate the transmittance of UI101 when it is white. ui The ratio determines K1.

[0096] K2 is the sum of the transmittance of the background 102 when it is white and the actual transmittance T of the background 102. b In one implementation, since each pixel of the background 102 has the same color scale value, the actual transmittance T of the background 102 can be determined according to the selected color scale value of the background 102. b Then, the transmittance of the background 102 when it is white and the actual transmittance T of the background 102 can be used to calculate the transmittance of the background 102. b The ratio determines K2.

[0097] The method for determining N is described below.

[0098] After the optical design of the HUD device is completed, the number of pixels in the area 103 covered by the light spot formed by the backflow of sunlight on the display panel 11 can be known. In one implementation, the number of pixels in the area 103 covered by the light spot can be obtained through optical path simulation. For example, the monitoring device can be configured to obtain the number of pixels in the area covered by the light spot through optical path simulation.

[0099] In some embodiments, the monitoring device can also be configured to determine whether sunlight backflow occurs in PGU10, and when it is determined that sunlight backflow does not occur, obtain the first intensity Q0, and when it is determined that sunlight backflow occurs, obtain the second intensity Q1 and the third intensity Q2.

[0100] In one implementation, whether sunlight backflow occurs may be determined based on the intensity of light sensed by the light sensor 13. For example, when the sensed intensity increases rapidly, sunlight backflow is determined to occur. In another implementation, whether sunlight backflow occurs may be determined based on the angle of sunlight. For example, when sunlight is detected to be at a specific angle, sunlight backflow is determined to occur.

[0101] In some implementations, the background 102 may be assigned a grayscale value that is smaller than the grayscale value of the UI 101 , so that the background 102 is invisible.

[0102] When the grayscale value assigned to the background 102 is low to a certain extent, the human eye cannot observe the background 102 under the high display brightness of the UI 101, so that the UI 101 observed by the human eye does not change. Thus, the display content provided by the UI 101 can always maintain a high quality.

[0103] In some embodiments, the monitoring device may be configured to output a protection strategy according to the fourth intensity and the duration of the corresponding light irradiating the display panel 11 .

[0104] For example, when the fourth intensity is greater than or equal to a threshold, the timing starts, and when the duration is greater than the set target time, the sunlight backflow protection strategy is output. It is also conceivable that when the product of the fourth intensity and the duration is greater than the set target value, the sunlight backflow protection strategy is output.

[0105] The sunlight backflow protection strategy may, for example, reduce the display brightness of the HUD device to reduce the amount of light passing through the display panel 11, or start a fan to cool the display panel 11, or rotate the reflector and shut down temporarily to avoid sunlight backflow to the display panel 11, etc.

[0106] In some examples, the monitoring device has a communication function and can access a wired network or a wireless network. In some examples, the monitoring device can receive data based on the wired network or the wireless network accessed. It can be understood that the monitoring device undertakes the calculation and processing work of the technical solution of the present disclosure, and the present disclosure does not limit this.

[0107] In some examples, the monitoring device has a communication function, accesses a wired or wireless network, obtains the temperature, time, and sunshine conditions of the vehicle's location, and outputs a sunlight backflow protection strategy based on whether there is sunlight backflow.

[0108] The monitoring device of the present disclosure may include one or more of the following components: a processor and a memory. Optionally, the processor uses various interfaces and lines to connect the various parts of the entire monitoring device, and executes various functions and processes data of the monitoring device by running or executing instructions, programs, code sets or instruction sets stored in the memory, and calling data stored in the memory. Optionally, the processor can be implemented in at least one hardware form of digital signal processing (DSP), field programmable gate array (FPGA), and programmable logic array (PLA). The processor can integrate one or more combinations of a central processing unit (CPU), a graphics processing unit (GPU), a neural network processor (NPU), and a baseband chip. Among them, the CPU mainly processes the operating system, UI, and application programs, etc., the GPU is responsible for rendering and drawing the content required to be displayed on the touch display, the NPU is used to implement artificial intelligence (AI) functions, and the baseband chip is used to process wireless communications. It is understandable that the above-mentioned baseband chip may not be integrated into the processor, but may be implemented by a separate chip.

[0109] The memory may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory may be used to store instructions, programs, codes, code sets, or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above various method embodiments, etc., and the data storage area may store data created according to the use of the monitoring device, etc.

[0110] In addition, those skilled in the art will appreciate that the monitoring device may include more or fewer components than those described above, or may combine certain components, or may have different component arrangements. For example, the monitoring device may also include a display screen, a camera assembly, a radio frequency circuit, an input unit, a sensor, an audio circuit, a WiFi module, a power supply, a Bluetooth module, and other components, which will not be described in detail herein.

[0111] According to another aspect of the present disclosure, Fig. 9 As shown in FIG. 1 , a HUD device 1 is also provided, which includes the above-mentioned PGU 10

[0112] In addition, the HUD device 1 may further include a reflecting device, which includes, for example, a first reflector 20 and a second reflector 30 , and the display light S emitted by the PGU 10 can be reflected by the second reflector 30 and the first reflector 20 in sequence and then emitted from the HUD device 1 .

[0113] According to another aspect of the present disclosure, Fig.10 As shown in , a monitoring method is also provided. The monitoring method is applicable to the above-mentioned PGU 10 and the above-mentioned HUD device 1, or the monitoring method is applicable to the following PGU, the PGU includes a display panel and a light sensor, the light sensor is arranged on the light-incoming side of the display panel, and is used to sense the intensity of light toward the display panel.

[0114] The monitoring method includes:

[0115] Acquire a first intensity sensed by the light sensor when there is no sunlight backflow in the PGU;

[0116] When sunlight backflow exists in the PGU, a second intensity sensed by the light sensor is obtained, and a third intensity sensed by the light sensor is obtained by assigning a non-zero gray value to the background of the image without changing the UI of the image displayed by the display panel; and

[0117] A fourth intensity of the light incident on the display panel from a light exiting side of the display panel opposite to the light entering side is determined according to the first intensity, the second intensity, and the third intensity.

[0118] The determining, according to the first intensity, the second intensity and the third intensity, of the fourth intensity of the light incident on the display panel from the light exiting side of the display panel opposite to the light entering side may include:

[0119] The fourth intensity is determined according to the first intensity, the second intensity, the third intensity, the first coefficient and the second coefficient, wherein the first coefficient is the ratio of the transmittance of the UI when it is white to the actual transmittance of the UI, and the second coefficient is the ratio of the transmittance of the background when it is white to the actual transmittance of the background.

[0120] The determining of the fourth strength according to the first strength, the second strength, the third strength, the first coefficient and the second coefficient may include:

[0121] The fourth intensity is determined according to the first intensity, the second intensity, the third intensity, the first coefficient, the second coefficient, the number of pixels in the area covered by the light spot formed by the backflow of sunlight on the display panel, and the transmittance of the pixels of the image when it is white.

[0122] In the present disclosure, the terms "first", "second", "third", "fourth", etc. are used only for the purpose of convenience of description and should not be regarded as limiting. In addition, although the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the specific embodiments described and shown in detail herein. Various changes may be made to the exemplary embodiments by those skilled in the art without departing from the scope defined by the claims of the present disclosure.

[0123] The features mentioned and / or shown in the above description of the exemplary embodiments of the present disclosure may be combined in the same or similar manner into one or more other embodiments, combined with the features in other embodiments or substituted for the corresponding features in other embodiments. The technical solutions obtained by these combinations or substitutions shall also be deemed to be included in the protection scope of the present disclosure.

Claims

1. An image generation unit, characterized in that: include: Display panel; a light sensor, disposed on the light-incoming side of the display panel, for sensing the intensity of light toward the display panel; as well as A monitoring device is configured to: obtain a first intensity sensed by the light sensor when there is no backflow of sunlight into the image generating unit; obtain a second intensity sensed by the light sensor when there is backflow of sunlight into the image generating unit, and obtain a third intensity sensed by the light sensor by assigning a non-zero grayscale value to the background of the image while the user interface of the image displayed on the display panel remains unchanged; and determine a fourth intensity of light incident on the display panel from a light output side of the display panel opposite to the light input side based on the first intensity, the second intensity, the third intensity, a first coefficient, a second coefficient, the number of pixels of an area covered by a light spot formed on the display panel by the backflow of sunlight, and the transmittance of the pixels of the image when white, wherein the first coefficient is a ratio of the transmittance of the user interface when white to the actual transmittance of the user interface, and the second coefficient is a ratio of the transmittance of the background when white to the actual transmittance of the background.

2. The image generation unit according to claim 1, characterized in that The monitoring device is configured to obtain the number of pixels of the area covered by the light spot through light path simulation.

3. The image generation unit according to claim 1 or 2, characterized in that: The monitoring device is configured to determine whether sunlight backflow occurs in the image generation unit, and to obtain the first intensity when it is determined that sunlight backflow does not occur, and to obtain the second intensity and the third intensity when it is determined that sunlight backflow occurs.

4. The image generation unit according to claim 3, characterized in that: The determination is performed based on the intensity sensed by the light sensor.

5. The image generation unit according to claim 1 or 2, characterized in that: The grayscale value assigned to the background is smaller than the grayscale value of the user interface so that the background is invisible.

6. The image generation unit according to claim 1 or 2, characterized in that: The monitoring device is configured to output a protection strategy according to the fourth intensity and the corresponding duration of the light irradiating the display panel.

7. A head-up display device, characterized in that: Comprising an image generation unit according to any one of claims 1 to 6.

8. A monitoring method, characterized in that: The monitoring method is applicable to the following image generation unit, the image generation unit includes a display panel and a light sensor, the light sensor is arranged on the light-incoming side of the display panel to sense the intensity of light toward the display panel, and the monitoring method includes: Acquire a first intensity sensed by the light sensor when there is no sunlight backflow into the image generation unit; When sunlight backflow exists in the image generation unit, a second intensity sensed by the light sensor is acquired, and a third intensity sensed by the light sensor is acquired by assigning a non-zero gray value to the background of the image without changing the user interface of the image displayed by the display panel; and The fourth intensity of the light incident on the display panel from the light output side of the display panel opposite to the light input side is determined based on the first intensity, the second intensity, the third intensity, the first coefficient, the second coefficient, the number of pixels of the area covered by the light spot formed by the backflow of sunlight on the display panel, and the transmittance of the pixels of the image when they are white, wherein the first coefficient is the ratio of the transmittance of the user interface when it is white to the actual transmittance of the user interface when the backflow of sunlight occurs, and the second coefficient is the ratio of the transmittance of the background when it is white to the actual transmittance of the background when the backflow of sunlight occurs.

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