JP2011203342A - On-board display device - Google Patents

Abstract

An in-vehicle display device that grasps the influence of ambient light in different directions and performs control suitable for an input video is obtained.
An input video signal information section 3 switches a plurality of video input signals and outputs a video signal, and obtains video features using the luminance of the video. The environment determination unit 4 obtains viewing environment information of the illuminance of the user who views the screen using the illuminance in different directions. Based on the viewing environment information from the environment determination unit 4 and the video characteristics from the input video signal information unit 3, the environment adaptation setting unit 5 is used to adjust the brightness setting value for adjusting the brightness of the screen 8 and the image quality of the video signal. Determine the image quality setting value. The luminance control unit 6 adjusts the luminance of the screen 8 using the luminance setting value from the environment adaptation setting unit 5. The video signal processing unit 7 adjusts the image quality of the video signal from the input video signal information unit 3 using the image quality setting value from the environment adaptation setting unit 5 and outputs the adjusted video signal to the screen 8. .
[Selection] Figure 1

Description

  The present invention relates to a display device having means for adjusting image quality in accordance with changes in ambient illuminance and the content of a display image, and more particularly to a vehicle-mounted display device.

  For example, a display device used in an environment where the brightness changes drastically, such as for in-vehicle use or for advertising purposes, for example, when viewing in a dark environment at night with image quality set in a bright environment during the day, the screen is too bright or set at night. If you watch in a bright environment in the daytime with high image quality, the screen will be too dark and the image will be difficult to see. As a countermeasure, conventional image display devices detect the ambient illuminance at which the display device is used with an illuminance sensor attached near the display screen, and determine the maximum, minimum, and average luminance values of the input video. A method has been proposed in which brightness and contrast are adjusted according to illuminance to improve visibility and obtain high image quality (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2006-285063 (pages 5-6, FIGS. 4-6)

  In a conventional image display device, an illuminance sensor is provided around the display surface, the illuminance incident on the display surface is measured, and the brightness and image quality of the screen are controlled according to the brightness environment around the display device. Yes. However, when the brightness of the driver's line of sight changes due to differences in the direction of sunlight, etc., there is a problem that the driver who has adapted to the brightness outside the vehicle may not be able to recognize the contents of the image display inside the vehicle. It was.

  The present invention has been made to solve the above-described problems, and provides an in-vehicle display device that grasps the influence of ambient light in different directions and performs control suitable for an input image.

  The in-vehicle display device according to the present invention includes an input video signal information unit, an environment determination unit, an environment adaptation setting unit, a luminance control unit, and a video signal processing unit. The input video signal information section switches a plurality of video input signals and outputs a video signal, and obtains video features using the luminance of the video. The environment determination unit obtains viewing environment information of the illuminance of the user who views the screen using the illuminance in different directions. The environment adaptation setting unit, based on the viewing environment information from the environment determination unit and the video features from the input video signal information unit, the brightness setting value for adjusting the brightness of the screen and the image quality setting value for adjusting the image quality of the video signal Ask for. The luminance control unit adjusts the luminance of the screen using the luminance setting value from the environment adaptation setting unit. The video signal processing unit adjusts the image quality of the video signal from the input video signal information unit using the image quality setting value from the environment adaptation setting unit, and outputs the adjusted video signal on the screen.

  According to the present invention, since the brightness and image quality of the screen are adjusted based on viewing environment information obtained from illuminance in different directions and the video characteristics of the video signal, the influence of ambient light is reduced and suitable for video signals. An on-vehicle display device that performs display is obtained.

It is a block diagram which shows the vehicle-mounted display apparatus of Embodiment 1 of this invention. It is a figure which shows the example of a measurement of the illumination intensity change in the vehicle of Embodiment 1, 5 of this invention. It is a figure which shows the driver | operator's eyes | visual_axis direction of Embodiment 1-3 of this invention. It is a figure which shows the example of the reference | standard brightness value with respect to the viewing environment illuminance value in Embodiment 1 of this invention. It is a figure which shows the example of the luminance ratio with respect to the image average luminance level of the video signal in Embodiment 1-5 of this invention. It is a figure showing the example of the image quality adjustment level with respect to the viewing environment illuminance value in Embodiment 1 of this invention. It is the figure which showed the example of a change of the image quality adjustment level when direct sunlight injects into the screen in Embodiment 1 of this invention. It is a block diagram which shows the vehicle-mounted display apparatus of Embodiment 2 of this invention. It is a figure which shows the example of the reference | standard brightness value with respect to the viewing environment illuminance value in Embodiment 2-5 of this invention. It is a figure showing the example of the image quality adjustment level with respect to viewing environment illuminance value in Embodiment 2-5 of this invention. It is the figure which showed the example in which the image quality adjustment level changes when direct sunlight irradiates the screen in Embodiment 2-5 of this invention. It is a block diagram which shows the vehicle-mounted display apparatus of Embodiment 3 of this invention. It is a figure which shows the example of arrangement | positioning of the light-receiving part in Embodiment 3 of this invention. It is a block diagram which shows the vehicle-mounted display apparatus of Embodiment 4 of this invention. It is a figure which shows the structural example of the light-receiving part for screens of Embodiment 4 of this invention. It is a block diagram which shows the vehicle-mounted display apparatus of Embodiment 5 of this invention. It is a figure which shows the example of the illumination intensity ratio in Embodiment 5 of this invention.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an in-vehicle display device according to Embodiment 1 of the present invention. At least one screen light receiving unit 1 of the illuminance detection unit is installed around the display screen side of the in-vehicle display device, and measures the brightness of the screen periphery. In addition, the outside light receiving unit 2 of the illuminance detection unit for detecting the illuminance in a direction different from this measures the brightness in the driving line of sight of the driver and the brightness outside the vehicle. For example, when it is attached to the back side of the rear-view mirror forward (vehicle traveling direction), it mainly detects the brightness of the driver's line of sight. When mounted on the dashboard below the windshield, the brightness outside the vehicle is mainly measured. Moreover, you may measure the brightness outside a vehicle using the luminance signal from a vehicle-mounted camera. In general, the brightness in the direction of the driver's line of sight corresponds to the brightness outside the vehicle, and correction by a certain factor is sufficient. Therefore, the outside light receiving unit 2 is set anywhere as long as it can receive outside light. May be.

  The input video signal information unit 3 is inputted with video input signals a, b, c, etc. to be displayed on the in-vehicle display device such as a navigation image signal, a TV image signal, a camera image signal from the in-vehicle camera, and the like. The video input signal is switched and the video signal is output, and video features such as average brightness, maximum brightness, and minimum brightness are detected.

  The environment determination unit 4 uses the illuminance in different directions, here, the illuminance obtained from the screen light receiving unit 1 and the outside light receiving unit 2 to view the screen of the in-vehicle display device. The environment is determined, and the viewing environment illuminance value L is obtained as the viewing environment information of the illuminance. Also, using the illuminance condition obtained from the screen light receiving unit 1, when the screen is brightly illuminated by direct sunlight or the like, the screen reflection is determined to be reflected on the screen. The environment adaptation setting unit 5 is based on the viewing environment information obtained from the environment determination unit 4, the screen reflection determination information, and the video characteristics of the video signal, and brightness setting conditions suitable for the user's viewing environment. Image quality setting conditions such as sharpness, color and contrast are obtained.

  The luminance control unit 6 adjusts the luminance of the backlight based on the luminance setting condition from the environment adaptation setting unit 5. The video signal processing unit 7 adjusts the video signal from the input video signal information unit 3 based on the image quality setting condition output from the environment adaptation setting unit 5. The screen 8 displays an adjusted image based on signals from the luminance control unit 6 and the video signal processing unit 7.

The operation of the in-vehicle display device configured as described above will be described. The environment determination unit 4 obtains the viewing environment illuminance value L based on the illuminance value L _f obtained from the screen light receiving unit 1 and the illuminance value L _out obtained from the outside light receiving unit 2. Specifically, as shown in the following equation (1), the illuminances of the screen light receiving unit 1 and the vehicle light receiving unit 2 are multiplied by arbitrary coefficients p, q, and (p + q = 1). The visual environment illuminance value L is calculated.
p × L _f + q × L _out = L (1)

  Figure 2 shows a typical sedan-shaped car on a cloudy day in August, on the dashboard under the windshield and at the center console where the car navigation system and car stereo are generally installed. It is an example which measured the illumination intensity change. The thick line is the illuminance on the dashboard, and the thin line is the illuminance at the center console. Thus, it can be seen that the illuminance measurement value differs depending on the illuminance measurement position.

  As shown in FIG. 3, the driver's line-of-sight direction during driving is directed to the outside of the vehicle, so that the driver is affected by light outside the vehicle, and the driver adapts to the outside light. Therefore, even when light is not directly applied to the screen of the in-vehicle display device, in order to set the image quality according to the environment outside the vehicle, it is preferable to set p = 0 and q = 1 in the equation (1). When considering the effect inside the vehicle, the ratio of p and q is changed. The ratio of p and q generally depends on the shape of the vehicle and the location where the display device is installed. In a car with a wide window glass and a display device that is close to the dashboard and easily affected by outside light, for example, p = 0.4, q = 0.6, or conversely, the window glass is narrow and the display device is recessed. Since the vehicle in the place is easily affected by the light in the vehicle, for example, p = 0.6 and q = 0.4.

  As shown in FIG. 4, the environment adaptation setting unit 5 obtains a reference luminance value (for example, 0 to 255 gradations) as a reference from the viewing environment illuminance value L obtained from the equation (1). This is because the brighter the viewing environment illuminance value L is, the brighter the screen is, and the brighter the screen is, the easier it is to see the screen. In addition, the environment adaptation setting unit 5 uses an image average luminance level (APL) in which the luminance is set to, for example, 0 to 255 gradations with respect to the average luminance of the image obtained in the input video signal information unit 3. The luminance ratio is also obtained as shown in FIG. This is because, in the case of an input video with a lot of white background, the average brightness level of the image will be high, and the amount of light received from the screen will increase, resulting in a feeling of glare. Because. By multiplying the luminance ratio by the reference luminance value, the optimum maximum display luminance is calculated and output to the luminance control unit 6 to control the luminance of the backlight.

  Further, the environment adaptation setting unit 5 determines an image quality adjustment level for video signal processing for the viewing environment illuminance value as shown in FIG. The video signal processing unit 7 performs image quality adjustment such as sharpness, black level adjustment, contrast adjustment such as gamma correction, and color adjustment. FIG. 6 shows an example of the change when the vertical axis is the sharpness intensity, for example. The sharpness is increased with respect to the increase in the viewing environment illuminance value to enhance the outline and make it easier to see. As described above, various image quality adjustment levels are set to be higher with respect to the increase in the viewing environment illuminance value to make it easy to see.

  4 to 6 are graphs, they may be tables or arithmetic expressions. The viewing environment illuminance value is not limited to the viewing environment illuminance value L when the luminance is determined, and may be changed for each image quality item to be adjusted. For example, two viewing environment illumination values are calculated, and the brightness adjustment viewing environment illumination value is obtained with p = 0 and q = 1 for brightness adjustment. For the black level adjustment of the screen, since it is affected by the brightness near the display surface, the viewing environment illuminance value for black level adjustment is obtained with p = 1 and q = 0. That is, by using different viewing environment illuminance values, the ratio of screen illuminance may be increased, and the black level may be determined based on this value.

  When the illuminance obtained from the screen light receiving unit 1 exceeds a predetermined value (screen reflection determination illuminance value), the environment determination unit 4 determines that direct sunlight is incident on the screen and adapts the screen reflection determination result to the environment. Output to the setting unit 5. The environment adaptation setting unit 5 increases the image quality adjustment level as shown in FIG. 7, and changes the video signal processing parameter to the image quality level setting in the case of direct sunlight. The video signal processing unit 7 performs image quality adjustment based on this information.

  Note that the screen light receiving unit 1 and the outside light receiving unit 2 do not have to be one each. For example, the light receiving unit for the screen can increase the light receiving accuracy of the screen by increasing it above and below the screen.

  In the vehicle-mounted display device configured as described above, the environment determination unit 4 obtains the viewing environment illuminance value L from the illuminance values in different directions as in the screen light receiving unit 1 and the outside light receiving unit 2. It is possible to measure the brightness environment in consideration of the influence of the person's gaze direction. Further, the input video signal information unit 3 detects video features such as average luminance from video signals displayed on a vehicle-mounted display device such as a navigation image signal, a television signal, and a camera signal. The environment adaptation setting unit 5 obtains a luminance setting condition suitable for the environment based on the viewing environment illuminance value L and the image characteristics, and sets image quality settings such as sharpness, color, and contrast suitable for the viewing environment. Also ask for conditions. The luminance control unit 6 and the video signal processing unit 7 adjust the image of the screen 8 by processing the video signal based on the luminance setting condition and the image quality setting condition from the environment adaptation setting unit 5. In this way, the brightness and image quality of the screen of the in-vehicle display device are adjusted based on the viewing environment illuminance value L obtained from the illuminance in different directions and the video characteristics of the video signal, thereby reducing the influence of environmental light. An in-vehicle display device that performs display suitable for the video signal is obtained.

  Further, since the image quality is adjusted based on the illuminance data obtained from the screen light receiver 1, the image quality is adjusted by determining the incidence of direct sunlight on the screen and the like, it is possible to set the image quality in accordance with the contrast reduction due to the direct light. . Thus, the viewing environment suitable for the driving environment can be measured, and even when direct light enters the screen, it is possible to perform image quality setting that emphasizes visibility.

Embodiment 2. FIG.
In the in-vehicle display device of the first embodiment, the environment adaptation setting unit 5 adjusts the image quality using the video luminance of the video signal from the input video signal information unit 3. However, the image quality condition required by the person who watches the display device differs depending on the type of content being displayed (television image, navigation image, vehicle-mounted camera image, etc.). For example, beauty and nature are required for TV images, but navigation images and in-vehicle camera images are required to have visibility such as easy-to-read characters and know what is being displayed. Since these require different image quality particularly in a bright environment, it is difficult to satisfy both requirements with the same image quality setting even in the same environment. Therefore, in the second embodiment, by further using a video type such as a navigation image, a TV signal, or a camera signal from the input video signal information unit, by changing the reference luminance value or changing the image quality adjustment level, An in-vehicle display device suitable for contents and easier to see will be described.

  FIG. 8 is a block diagram showing an in-vehicle display device according to Embodiment 2 of the present invention. The image quality control of this in-vehicle display device is the same as that of the first embodiment except for the input video signal information unit 31. The input video signal information unit 31 sets not only video features such as the average luminance of the input video signal but also video type information (navigation image signal, TV signal, camera signal, etc.) of the content of the input signal and environment adaptive setting. To the department. Specific methods include determining the video type from the switch signal when the user switches the content, moving the image of the input signal (generally the movement is slow on the navigation screen, TV is fast, etc.), and the audio signal It may be judged from such as.

  The operation of the in-vehicle display device configured as described above will be described. The environment determination unit 4 multiplies the video input signals a, b, c, etc. by an arbitrary coefficient from both the illuminances of the screen light receiving unit 1 and the outside light receiving unit 2, and is the same as the equation (1) The viewing environment illuminance value L is calculated.

  As shown in FIG. 3, the line-of-sight direction of the driver who is driving while using the navigation is facing the outside of the vehicle, and thus is affected by light outside the vehicle. On the other hand, when watching a TV image with the car stopped, the line of sight is directed to the screen, and therefore, it is affected by light around the screen. Therefore, the environment determination unit 4 considers the influence of the two light receiving units based on the type information from the input video signal information unit, calculates the viewing environment illuminance value L from the equation (1), and sends it to the environment adaptation setting unit 5. Output.

  That is, since it is influenced by outside light during driving, it is input to the environment determination unit 4 that it is a navigation screen, and q is set high to obtain the viewing environment illuminance value L (close to the illuminance value of outside light) Become). On the other hand, when viewing a TV image with the car parked, the watch point is on the navigation screen and affects the brightness around the display device. Therefore, the fact that the image is a TV image is input to the environment determination unit 4 and p is increased. To obtain the viewing environment illuminance value L (close to the illuminance value of the center console). The viewing environment illuminance value L may be obtained regardless of the type information of the video signal, or the viewing environment illuminance value L may be obtained for each video signal.

  Note that although three video input signals are described here as an example, the number of input signals is not limited to three. Further, it is not necessary for each of the screen light receiving unit 1 and the vehicle light receiving unit 2 to be one. For example, as a light receiving unit for the outside of the vehicle, a light receiving unit for the outside of the vehicle behind the vehicle is provided, the brightness is obtained from the luminance information of the image from the back camera, and the light receiving unit for the screen is increased above and below the screen. Thereby, the illuminance measurement accuracy in the line-of-sight direction can be increased.

  The viewing environment illuminance value L calculated by the environment determination unit 4 is input to the environment adaptation setting unit 5. As shown in FIG. 9, the environment adaptation setting unit 5 obtains a reference luminance value for the viewing environment illuminance value L using the video type from the input video signal information unit 31. For example, when a video input signal a (for example, a navigation image) is input, the reference luminance is set higher than when a video input signal b (for example, a TV signal) is input. This is to make the navigation screen easier to see.

  The calculation of the maximum display brightness obtained from the reference brightness value and the brightness ratio of FIG. 5 is performed in the same manner as in the first embodiment.

  As shown in FIG. 10, the environment adaptation setting unit 5 places importance on visibility by selecting image quality condition settings for sharpness, color, and contrast according to the type of video input from the input video signal information unit 31. It is possible to automatically select whether to set the image quality setting with emphasis on beauty and naturalness, determine the image quality adjustment level according to it, and output it to the video signal processing unit 7. That is, the video input signal b (eg TV signal) lowers the image quality adjustment level with respect to the video input signal a (eg navigation screen). This prevents unnatural images from appearing when converting image quality to improve visibility when viewing TV images, or conversely, when converting image quality for TV images that are conservative when navigating. It is possible to prevent problems such as poor visibility.

  Also, as shown in FIG. 11, when the illuminance obtained from the screen light receiving unit 1 exceeds a predetermined value (screen reflection determination illuminance value), the image quality is changed in response to direct sunlight depending on the type of video signal. Or not.

  For example, since it is important to improve the visibility of the navigation screen, the image quality adjustment level is gradually increased up to 100000 [lx] illuminance as in the case of the video input signal a in FIG. If it exceeds [lx], it is determined that it has been exposed to direct sunlight, and the image quality adjustment level is greatly increased to achieve an image quality setting with high visibility. On the other hand, when the user stops and views a television image, the image quality setting level of the image input signal b in FIG. 11 is selected. Since it is important to enhance the beauty and naturalness of the image rather than the visibility, the setting is such that the luminance change in the backlight adjustment of the luminance control unit 6 and the image quality setting change by the video signal processing unit 7 are small.

  In this way, even when the screen reflection determination illuminance value exceeds a predetermined value due to direct sunlight, the television image (video input signal b) maintains a natural feeling without abrupt adjustment of the image quality adjustment level, and vice versa. In addition, on the navigation screen (video input signal a), visibility is improved by performing rapid processing. In this way, automatic processing to the required image quality of each content becomes possible.

  In the vehicle-mounted display device configured as described above, the environment determination unit 4 includes the illuminance values in different directions and the image from the input video signal information unit 31 as in the screen light receiving unit 1 and the vehicle light receiving unit 2. Based on the type information, the viewing environment illuminance value L suitable for the driver's line-of-sight direction and purpose of use can be obtained. The input video signal information unit 31 detects video type information to be displayed on a vehicle-mounted display device such as a navigation image signal, a TV signal, and a camera signal, and video features such as average luminance of the video signal, and an environment adaptation setting unit 5 obtains brightness setting conditions suitable for the environment based on the viewing environment illuminance value L, the video type information, and the video characteristics, and the image quality such as sharpness, color, and contrast suitable for the viewing environment. Since the setting condition is obtained, the luminance control unit 6 and the video signal processing unit 7 process the video signal based on the luminance setting condition and the image quality setting condition from the environment adaptation setting unit 5 and adjust the image on the screen 8. An in-vehicle display device that performs display suitable for content can be obtained.

  In addition, depending on the video type based on the video signal information, whether to set the image quality setting with emphasis on visibility or the image quality setting with emphasis on beauty and naturalness is automatically selected. When the user is driving, the switching of the image quality is refrained, and when driving while watching the navigation screen or the camera image during driving, it is possible to instantaneously switch to the image quality with high visibility. Therefore, an in-vehicle display device suitable for content can be obtained. Further, based on the illuminance data obtained from the screen light receiver 1, image quality settings can be set for each content in accordance with the contrast reduction due to light directly incident on the screen.

Embodiment 3 FIG.
The in-vehicle display devices of the first and second embodiments have the vehicle exterior light receiving unit 2, but in the third embodiment, the directional reflected light reception that detects the reflection of the screen toward the user. An in-vehicle display device that improves the visibility of the screen by providing a unit will be described.

  FIG. 12 is a block diagram showing an in-vehicle display device according to Embodiment 3 of the present invention. The image quality control of the in-vehicle display device according to the present embodiment detects the reflection of the screen in the direction of the user as an illuminance detection unit instead of the in-vehicle light receiving unit 2 of the in-vehicle display device of FIG. A directional reflected light receiving unit 11 is provided. For example, as shown in FIG. 13, the specific installation locations are arranged on the periphery of the screen 8 as in the case of the screen light receiving unit 1 having a wide sensing area. Further, the directional reflected light receiving unit 11 is installed in the direction in which the user 20 detects the specular reflection of the sunlight 21 toward the user.

  The environment determination unit 4 determines the light environment of the person who uses the display device based on the illuminance conditions obtained from the screen light receiving unit 1 and the reflected light receiving unit 11. Except this, it is the same as the in-vehicle display device of FIG. 8 of the second embodiment.

The operation of the in-vehicle display device configured as described above will be described. As shown in the following equation (2), the environment determination unit 4 receives the illuminance L _f from the screen light receiving unit 1 and the reflected light receiving unit 11 for the video input signals a, b, c and the like. The viewing environment illuminance value L is calculated by multiplying the illuminance L _{ref by} an arbitrary coefficient r, s, (r + s = 1). Note that either the illuminance value L _f obtained from the screen light receiving unit 1 or the illuminance value L _ref obtained from the reflected light receiving unit 11 may be selected according to the environment or content. This case is the same as when either r or s is 1.
r × L _f + s × L _ref = L (2)

  As shown in FIG. 3, the driver's line-of-sight direction during driving is directed to the outside of the vehicle, and thus is affected by light outside the vehicle. On the other hand, when watching a TV image with the car stopped, the line of sight is directed toward the screen, and therefore, it is affected by the light around the screen. Therefore, the environment determination unit 4 selects the coefficients r and s in consideration of the influence of the two light receiving units based on the type information from the input video signal information unit, obtains the viewing environment illuminance value L, and the environment adaptation setting unit. Output to 5. The viewing environment illuminance value L may be obtained regardless of the type information of the video signal, or the viewing environment illuminance value L may be obtained for each video signal.

  The viewing environment illuminance value L obtained by the environment determination unit 4 is input to the environment adaptation setting unit 5. The reference luminance value for the viewing environment illuminance value obtained from FIG. 9, the calculation of the maximum display luminance obtained from the luminance ratio in FIG. 5, and the image quality setting value obtained from FIG. 10 are the same as those in the second embodiment.

  As shown in FIG. 11, when the illuminance obtained from the reflected light receiving unit 11 exceeds a predetermined value, the environment determining unit 4 determines that the light that is specularly reflected on the screen is directed toward the driver. The screen specular reflection determination result is output to the environment adaptive setting unit 5 as the reflection determination. The environment adaptation setting unit 5 raises the brightness setting value and image quality adjustment level assuming specular reflection light, and sets video signal processing parameters. Specifically, visibility is improved by increasing the level of gamma characteristics, color conversion, sharpness processing, and luminance.

  The environment determination unit 4 outputs the first screen reflection determination result to the environment adaptation setting unit 5 when the illuminance obtained from the screen light receiving unit 1 exceeds a predetermined value, and further, the reflected light receiving unit When the illuminance obtained from 11 exceeds a predetermined value, the screen specular reflection determination result may be output to the environment adaptation setting unit 5 as the second screen reflection determination result. Using these determination results, the environment adaptation setting unit 5 adjusts the luminance and image quality when the screen is brightened by sunlight and when the sunlight is further specularly reflected and reflected in the user direction. Note that this may change the rate of change according to the video type of the content.

  In addition, although this Embodiment was provided with the reflected light light-receiving part 11 instead of the light receiving part 2 for vehicle exteriors of FIG. 8 of Embodiment 2, of the light receiver 2 for vehicle exteriors of FIG. Instead, the reflected light receiving unit 11 may be provided, and the luminance and image quality may be adjusted as in the first embodiment.

  In the vehicle-mounted display device configured as described above, the environment determination unit 4 includes the illuminance values in different directions such as the screen light receiving unit 1 and the reflected light receiving unit 11 and the video type from the input video signal information unit 31. Based on the information, it is possible to obtain a viewing environment illuminance value L suitable for the driver's line-of-sight direction and purpose of use, and based on this, the luminance setting condition and the image quality setting condition are changed. . In addition, it is possible to grasp the influence of the mirror reflection on the screen and set the image quality according to the contrast reduction due to the reflected light reflected on the screen based on the illuminance data obtained from the reflected light receiving unit 11. An in-vehicle display device excellent in performance can be obtained.

Embodiment 4 FIG.
The in-vehicle display devices according to the first to third embodiments have two light receiving units, but in the fourth embodiment, an optimum display is performed by using one light receiving unit. An in-vehicle display device will be described.

  FIG. 14 is a block diagram showing the configuration of the fourth embodiment of the present invention. The image quality control of the in-vehicle display device according to the present embodiment has a configuration without the vehicle exterior light receiving unit 2 in the second embodiment or a configuration without the reflected light receiving unit 11 in the third embodiment. The light receiving unit 12 can measure illuminance in different directions. For example, the screen light receiving unit 12 measures the illuminance around the in-vehicle display device over a wide range, or detects the illuminance in a certain direction, for example, the illuminance in the vehicle exterior direction or the reflection of the screen in the user direction. Although there are several methods, for example, as shown in FIG. 15, a wide range of illuminance is obtained by dividing the light receiving areas 12a to 12c of the screen light receiving unit 12 into a plurality of areas and obtaining the illuminance for each area. For example, it is possible to obtain the illuminance in the direction in which the specular reflection of the sunlight 21 toward the user is detected. Further, the illuminance of light in a plurality of directions may be measured by providing a shutter on the upper surface of the screen light receiving unit 12 and adjusting the opening direction of the shutter. Further, by using a directional light receiving unit and moving it to the left and right, the illuminance in a plurality of directions may be measured, or the illuminance in the left and right may be integrated to obtain a wide range of illuminance.

The operation of the in-vehicle display device configured as described above will be described. Environment determination unit 4, a video input signal a, b, with respect to c and the like, as shown in (3) below, the illuminance L _a certain direction the screen light receiving unit 12 is measured, the same screen to illuminance L _b other direction use light receiving portion 12 is determined, arbitrary coefficient t, u, calculates the viewing environment illuminance value L by multiplying the (t + u = 1).
t × L _a + u × L _b = L (3)

Incidentally, extensively to measure the illuminance of the peripheral vehicle display device as a L _a, when measuring the vehicle exterior direction of the light as L _b performs the same image processing as in the second embodiment. Further, when extensively measure the illuminance of the surrounding vehicle display device as a L _a, to measure the direction of illumination for detecting the specular reflection of sunlight 21 to the user direction L _b is similar to the third embodiment Perform image processing.

  In the in-vehicle display device configured as described above, since the number of light receiving portions can be reduced, an in-vehicle display device having excellent visibility can be obtained at low cost. Further, in FIG. 15, the driver can obtain an in-vehicle display device that reduces the influence of sunlight by using the illuminance of the light receiving area 12a. Similarly, the passenger seat person uses the illuminance of the light receiving area 12c. An in-vehicle display device with reduced influence of sunlight can be obtained. Furthermore, a person in the rear seat can obtain an in-vehicle display device that reduces the influence of sunlight by using the illuminance of the light receiving area 12b. As described above, an in-vehicle display device having excellent visibility can be obtained by reducing the influence of the user's sunlight according to the seat to be used.

Embodiment 5 FIG.
The in-vehicle display device of the fourth embodiment measures the illuminance in a plurality of directions by using one light receiving unit as the illuminance detecting unit. However, in the fifth embodiment, a plurality of light receiving units are previously provided. Is used to measure the illuminance in a plurality of directions, and the illuminance ratio obtained from the illuminance in the plurality of directions is used to convert the illuminance value from one light receiving unit, thereby pseudo An in-vehicle display device that calculates a viewing environment illuminance value replaced with illuminance and performs optimal display will be described.

  FIG. 16 is a block diagram showing the configuration of the fifth embodiment of the present invention. The image quality control of the in-vehicle display device according to the present embodiment has a configuration without the vehicle exterior light receiving unit 2 in the second embodiment.

First, the illuminance in a plurality of directions is measured using a plurality of light receiving units. Thereby, for example, a result as shown in FIG. 2 is obtained. Using this, as shown in FIG. 17, the luminance ratio v of the dashboard with respect to the center console is obtained. In this case, it is about 3 times (v≈3). The illuminance L _out outside the vehicle during driving is converted as an illuminance value that is three times the illuminance L _f obtained from the light receiving unit for screen installed near the center console. Note that the illuminance value obtained from the screen light receiver and the illuminance value in the line-of-sight direction (light outside the vehicle) are not limited to three times, and the relationship between the screen light receiver and the illuminance in the line-of-sight direction is measured for each vehicle. It can be set arbitrarily.

In this way, the illuminance environment in the driver's line-of-sight direction is calculated. That is, with respect to the illuminance value L _f obtained from the screen light receiving unit 1, the illuminance value L _out obtained from the outside light receiving unit 2 can be approximated as shown in Equation (4).
L _out = v × L _f (4)

Substituting this into the equation (1) and multiplying the illuminance L _f of the screen light receiving unit 1 by an arbitrary coefficient p, q, (p + q = 1) as shown in the following equation (5). The visual environment illuminance value L is calculated. Thereafter, the same image processing as in the second embodiment is performed.
p × L _f + q × v × L _f = L (5)

In the present embodiment, the screen light receiving unit 1 disposed around the screen is used. However, for example, the vehicle light receiving unit 2 disposed on the dashboard or the like may be used. In this case, L _f can be approximated as in equation (6), and the luminance ratio w is approximately 1/3 (w≈1 / 3).
L _f = w × L _out (6)

Substituting this into the equation (1), as shown in the following equation (7), the illuminance L _out of the vehicle exterior light receiving unit 2 is multiplied by an arbitrary coefficient p, q, (p + q = 1) and viewed. The visual environment illuminance value L is calculated. Thereafter, image processing similar to that in the second embodiment may be performed.
p × w × L _out + q × L _out = L (7)

In the same manner as FIG. 11 in the second embodiment, L _f, or, (6) L _f using converted from L _out by equation performs screen reflection determination when this exceeds a predetermined value, the video signal The image quality adjustment may be changed depending on the type.

  In the in-vehicle display device configured as described above, if the illuminance in a plurality of directions is measured in advance using a plurality of light receiving units, and the viewing environment illuminance value L is calculated by obtaining the illuminance ratio therefrom. For this reason, it is sufficient if there is only one ordinary light receiving unit near the screen. Therefore, an in-vehicle display device excellent in visibility according to the content can be obtained at a low cost. Further, when there is an illuminance sensor attached to the vehicle, the illuminance is obtained from this, and when there is an in-vehicle camera, the brightness outside the vehicle may be obtained from the luminance information of the camera signal. In these cases, it is only necessary to obtain the viewing environment illuminance value L from the previously obtained illuminance ratio and adjust the image. Therefore, the in-vehicle display device does not require an illuminance sensor, and has excellent visibility according to the content. A display device can be obtained at a lower cost.

DESCRIPTION OF SYMBOLS 1 Light receiver for screens 2 Light receiver for vehicles outside 3 Input video signal information part 4 Environment determination part 5 Environment adaptation setting part 6 Brightness control part 7 Video signal processing part 8 Screen 11 Reflected light receiver 12 Light receiver for screen 20 User 21 Nikko 31 Input video signal information section

Claims (7)

An input video signal information unit that switches a plurality of video input signals and outputs a video signal, and obtains video characteristics using the luminance of the video;
An environment determination unit that obtains viewing environment information of the illuminance of a user who views the screen using illuminance in different directions;
Based on viewing environment information from the environment determination unit and video characteristics from the input video signal information unit, a luminance setting value for adjusting the luminance of the screen and an image quality setting value for adjusting the image quality of the video signal are obtained. An environmental adaptation setting unit;
A luminance control unit that adjusts the luminance of the screen using the luminance setting value from the environment adaptation setting unit;
An in-vehicle device comprising: a video signal processing unit that adjusts an image quality of a video signal from the input video signal information unit using an image quality setting value from the environment adaptation setting unit and outputs the adjusted video signal on the screen Display device. The input video signal information unit further determines the video type of the video signal,
The environment determination unit obtains viewing environment information using the illuminance in the different directions based on the video type from the input video signal information unit,
2. The vehicle-mounted device according to claim 1, wherein the environment adaptation setting unit obtains a luminance setting value and an image quality setting value using the viewing environment information, the video type from the input video signal information unit, and the video feature. Display device.   The environment determination unit, as the illuminance in the different direction, the illuminance from the light detection unit for the screen that detects the brightness of the periphery of the screen and the illuminance from the external light detection unit that detects the brightness outside the vehicle, or The vehicle-mounted display device according to claim 1, wherein the illuminance from the screen light detection unit and the illuminance from the reflected light detection unit that detects reflection of light on the screen toward the user are used. The environment determination unit further obtains screen reflection determination information when the illuminance from the screen light detection unit or the illuminance from the reflected light detection unit exceeds a predetermined value,
The in-vehicle display device according to claim 3, wherein the environment adaptation setting unit obtains a luminance setting value and an image quality setting value by further using screen reflection determination information from the environment determination unit. An input video signal information unit that switches a plurality of video input signals and outputs a video signal, and obtains video characteristics using the luminance of the video;
A user who obtains an illuminance ratio between the illuminance of the illuminance detection unit for detecting the brightness of the surroundings and the illuminance in a direction different from the illuminance in advance and views the screen using the illuminance ratio and the illuminance of the illuminance detection unit. An environment determination unit for obtaining visual environment information of the illuminance of
Based on viewing environment information from the environment determination unit and video characteristics from the input video signal information unit, a luminance setting value for adjusting the luminance of the screen and an image quality setting value for adjusting the image quality of the video of the video signal An environment adaptation setting unit for
A luminance control unit that adjusts the luminance of the screen using the luminance setting value from the environment adaptation setting unit;
An in-vehicle device comprising: a video signal processing unit that adjusts an image quality of a video signal from the input video signal information unit using an image quality setting value from the environment adaptation setting unit and outputs the adjusted video signal on the screen Display device. The input video signal information unit further determines the video type of the video signal,
The environment determination unit obtains viewing environment information using the illuminance ratio and the illuminance of the illuminance detection unit based on the video type from the input video signal information unit,
The in-vehicle setting according to claim 5, wherein the environment adaptation setting unit obtains a luminance setting value and an image quality setting value using the viewing environment information, a video type from the input video signal information unit, and the video feature. Display device. The environment determination unit further obtains screen reflection determination information when the illuminance from the illuminance detection unit exceeds a predetermined value,
The in-vehicle display device according to claim 6, wherein the environment adaptation setting unit obtains a luminance setting value and an image quality setting value by further using screen reflection determination information from the environment determination unit.

Images