JP2009244700A - Image display - Google Patents

Abstract

To improve visibility in an image display device used under a strong light source.
An image display means for displaying an image, a detection means for detecting an illuminance distribution on the surface of the image display means, and the luminance of the image display means based on the illuminance distribution detected by the detection means, or And adjusting means 30 for adjusting at least one of the contrasts.
[Selection] Figure 3

Description

  The present invention relates to brightness and contrast adjustment in various image display apparatuses.

  In recent years, flat panel displays (FPDs) have become larger and more popular, and large flat panel displays such as liquid crystal panels are also being used in vehicle instrument panels (hereinafter referred to as “instrument panels”). Patent Document 1 discloses that various types of instruments such as a speedometer, which has been conventionally performed mechanically, are displayed on an image display using such a flat panel display, imitating an analog meter image. Disclosure.

  In recent years, the performance of flat panel displays has been remarkably improved, and those that can be seen under sunlight have also appeared. If such a flat panel display is used as an instrument panel, it is not necessary to cover the instrument panel with a shade or the like in order to avoid direct sunlight, and the interior interior design can be expected to be greatly improved.

In addition, the spread of flat panel displays is progressing in notebook personal computers and various information terminal devices, and opportunities to use these devices outdoors are increasing.
JP 2004-157434 A

  The flat panel in the instrument panel of the vehicle has many advantages such as improved design, but unlike conventional mechanical instruments, when strong light such as the sun is directly incident on the screen, the reflected light The visibility of the display screen will deteriorate. Even if the incident angle of light does not directly affect the viewer, if the surface treatment is applied with fine irregularities such as anti-glare on the display screen, the light is irregularly reflected at the surface treatment portion. And visibility will deteriorate. In addition, when strong light is incident on a part of the screen, the human eye cannot adjust contrast for both the light incident part and the shadowed part. The visibility in the part which has become will fall.

  When a flat panel display is used as an instrument panel of a vehicle, if the visibility deteriorates due to the above phenomenon, in the worst case, various instruments displayed on the instrument panel may not be visible and may be in a dangerous state. There is sex. To improve visibility, it is conceivable to install a shade on a flat panel display or install it on a hood or other such hood. However, if such a configuration is adopted, the degree of freedom of design for the entire cockpit is limited. It becomes what was done.

  The above-mentioned visibility problems in flat panels can easily be expected not only in display devices such as instrument panels, but also in notebook computers and various information terminal devices that will be used more outdoors in the future. it can.

  In order to solve the above problems, an image display device according to a first aspect of the present invention includes an image display means for displaying an image, a detection means for detecting an illuminance distribution on the surface of the image display means, and an illuminance distribution detected by the detection means. And adjusting means for adjusting at least one of luminance and / or contrast of the image display means.

  Further, the invention according to claim 2 is characterized in that the adjusting means adjusts at least one of brightness and contrast of the entire image display means.

  Furthermore, the invention according to claim 3 is characterized in that the adjusting means adjusts at least one of partial luminance and contrast of the image display means.

  According to the first aspect of the present invention, in the image display device used under a strong light source, it is possible to adjust at least one of the brightness of the screen or the contrast using the illuminance distribution on the screen, A screen with high visibility can be provided.

  According to the invention of claim 2, it is possible to adjust the luminance of the entire screen or at least one of the contrast using the illuminance distribution on the screen, and to provide a screen with high visibility. Become.

  According to the invention of claim 3, it is possible to adjust at least one of partial luminance or contrast on the screen using the illuminance distribution on the screen, and to provide a screen with high visibility. It becomes possible.

  FIG. 1 is a diagram showing a vehicle 1 positioned under various light sources 2. Reference numeral 1 denotes a vehicle (own vehicle), 2 denotes a light source, and 3 denotes incident light from the light source. The vehicle 1 is positioned with its front facing in a certain direction. The light source 2 may be a relatively bright illumination by the sun during the day and by a street lamp at night. Incident light 3 from the light source 2 is incident at a predetermined angle with respect to the direction in which the vehicle 1 is directed, and the angle changes with time due to a change in the direction of the vehicle 1 accompanying movement.

  FIG. 2 is a diagram schematically showing the inside of the vehicle 1, wherein 4 is a driver's seat, and 5 is an instrument panel as image display means in the present invention. The instrument panel 5 is composed of a flat panel display using a liquid crystal panel, a plasma panel, an organic EL panel, or the like. On the screen, although not shown, various instruments such as a speedometer, a tachometer, a fuel gauge, and a water temperature meter, which have conventionally been configured with mechanical instruments, use objects in the field of computer graphics. An image is formed.

  For example, in a vehicle speedometer, a display board on which speed is written, a pointer, an edge of a meter, and the like are each formed by an object, and a vehicle speedometer based on an image is configured by combining these. This speedometer instrument is based on the speed pulse received from the vehicle 1 and is created to rotate on the display board so that the speed is displayed (comment: not limited to the tachometer type). A similar movement is realized. Note that the object constituting the image may be either two-dimensional or three-dimensional.

  In addition to the various instruments described above, a navigation screen, a screen for displaying various information, and the like may be displayed on a part of the instrument panel 5. In order to display various instruments, buildings in the navigation screen, etc. on the instrument panel 5, a relatively large instrument panel 5 is required. If the large instrument panel 5 is used, the influence of the incident light 3 inserted into the instrument panel 5 cannot be avoided, and the above-described problem of visibility due to reflection or partial irradiation occurs. Furthermore, if the design is emphasized and the instrument panel is not provided with a hood or shade, the influence of the incident light 3 is further increased.

In the present invention, in order to correspond to the incident light 3 inserted into the instrument panel 5 as such an image display means, the illuminance distribution on the surface of the instrument panel 5 is detected, and the brightness and contrast of the instrument panel 5 are determined based on the detected illuminance distribution. Adjust and provide a highly visible screen. In addition, since the above-mentioned visibility problem can be dealt with by adjusting brightness, contrast, etc., the degree of freedom of design of the image display means that will be regarded as important in proportion to the size, or the surrounding design It will be much improved.

  In the present invention, various techniques are used for adjusting brightness, contrast, and the like. For example, in an image display device such as a liquid crystal television that has been developed in recent years, there is an area control technique that instantaneously and locally controls the light emission of the backlight. This technique is a technique that highlights the black part by not lighting the backlight locally in the black part of the image, but if such a technique is used, the light emission of the backlight is partially adjusted. Thus, partial brightness adjustment and contrast adjustment can be performed.

  In addition, in the image display means using self-luminous elements such as organic EL, since self-luminous elements are used, it is possible to control light emission for each element, and as in the area control technology, partial brightness adjustment and contrast adjustment are possible. Can be done.

  Further, in the present invention, various detection methods using the current technology can be considered as a method for detecting the illuminance distribution on the surface of the image display means. In this specification, two embodiments will be described. I will do it. In the present invention, the present invention is not limited to these embodiments, and any technique can be used as long as it can detect the illuminance distribution on the surface of the image display means.

  3 to 5 illustrate the first embodiment of the present invention. FIG. 3 is a diagram showing the main configuration of the image display apparatus of the present invention, and FIG. 4 is installed on the instrument panel. FIG. 5 is a diagram illustrating an illuminance detection sensor, and FIG. 5 is a diagram illustrating a flow of luminance correction according to the present invention.

  In FIG. 3, an instrument panel 5 as image display means in the present invention and an illuminance sensor 7 as illuminance distribution detection means in the present invention are arranged in a vehicle 1 as the own vehicle.

  The instrument panel 5 is image display means for presenting various images to the driver as described above, and is capable of partial brightness adjustment and contrast adjustment as well as normal brightness adjustment and contrast adjustment.

  Reference numeral 7 denotes an illuminance sensor, which is composed of, for example, transparent illuminance sensor cells arranged on the instrument panel surface. This will be described later.

  The instrument panel light processing system includes an instrument panel incident light state determination ECU 20 and an instrument panel brightness adjustment ECU 30. The instrument panel incident light state determination ECU 20 is provided with an illuminance distribution determination unit 21 for determining the illuminance distribution on the surface of the instrument panel 5 based on a signal received from the illuminance sensor 7.

  The instrument panel brightness adjustment ECU 30 includes an overall brightness determination unit 31, an overall brightness DB 32, a partial brightness determination unit 33, a partial brightness DB 34, and a brightness correction processing engine 35.

The overall luminance determining unit 31 determines the overall luminance of the instrument panel 5 based on the illuminance distribution determined by the illuminance distribution determining unit 21. In this embodiment, a database stored in the overall brightness DB 32 is used for this determination. However, the overall brightness may be determined using a calculation formula as appropriate without using such a database. However, since the ideal overall luminance is based on various factors described later, the use of the database in this way is a preferable form without any special calculation.

  Since the determination of the overall luminance mainly depends on the average luminance of the instrument panel 5, it may be performed by calculating the average luminance from the illuminance distribution or acquiring the average luminance from the illuminance sensor 7.

  The overall brightness DB 32 stores the overall brightness according to the illuminance distribution or the overall brightness according to the average brightness as a database. The visibility of the instrument panel 5 is affected not only by the intensity of light inserted and the illumination distribution, but also by a number of factors such as the type of flat panel display, coating treatment such as anti-glare and anti-reflection, and the layout of the flat panel display in the room. Will receive. Since it is very difficult to calculate ideal visibility based on all these factors, in the present invention, tests are performed in various environments in which these factors are aligned in advance, and ideal visibility is achieved. The relationship between the obtained illuminance distribution and the overall luminance, or the relationship between the average illuminance and the overall luminance is made into a database and used.

  The partial luminance determining unit 33 determines the partial luminance of the instrument panel 5 based on the illuminance distribution determined by the illuminance distribution determining unit 21. In the present embodiment, a database stored in the partial luminance DB 34 is used for this determination. However, as with the determination of the overall luminance, the overall luminance may be determined appropriately using a calculation formula.

  Similar to the overall brightness DB 32 described above, the partial brightness DB 34 performs a test under various environments in which a plurality of factors are arranged, and stores the relationship between the illuminance distribution and the partial brightness at which ideal visibility is obtained as a database. Yes.

  The brightness correction processing engine 35 adjusts the brightness of the instrument panel 5 by using either or both of the overall brightness determined by the overall brightness determining unit 31 and / or the partial brightness determined by the partial brightness determining unit 33. A screen with high visibility according to the surface state of the screen will be provided.

  FIG. 4 shows an example of the illuminance sensor 7 that detects the illuminance distribution on the surface of the instrument panel 5. The illuminance sensor 7 includes a plurality of transparent illuminance sensor cells 6 arranged in an array on the instrument panel 5. The transparent illuminance sensor cell 6 is formed using, for example, a transparent solar cell, and detects that light is exposed to itself. FIG. 4 (B) is a diagram showing how the illuminance sensor 7 detects the light irradiation. The transparent illuminance sensor cell 6 shown in white is a sensor cell exposed to light, and the filled one is shown in FIG. A sensor cell that is not exposed to light is shown. Thus, the illuminance distribution on the surface of the instrument panel 5 can be detected by the transparent illuminance sensor cells 6 arranged in an array.

  Further, the transparent illuminance sensor cell 6 may detect not only whether the light is exposed but also the intensity of the light. With such a configuration, it is possible to detect the illuminance distribution including the light intensity, so that the luminance can be adjusted with higher accuracy.

  In the embodiment shown in FIG. 4, a large number of transparent illuminance sensor cells 6 are arranged. However, the illuminance distribution can be easily measured by arranging at least two transparent illuminance sensor cells 6. In that case, the illuminance distribution may be estimated by interpolating between the sensor cells 6.

Moreover, it replaces with the structure which arrange | positions the transparent illumination intensity sensor cell 6 on the instrument panel 5, and several illumination intensity sensor cells may be arrange | positioned around the instrument panel 5, and the illumination intensity distribution in the instrument panel 5 surface may be measured based on those outputs. In such a configuration, since it is not necessary to arrange the illuminance detection unit 7 on the surface of the instrument panel 5, a clear image can be provided.

  The luminance correction process performed based on the main configuration of the first embodiment described above will be described. FIG. 5 is a diagram showing a flow of luminance correction processing.

  When the power of the image display device is turned on, the luminance correction process is started (step S100). In step S <b> 101, the illuminance distribution determination unit 21 determines the illuminance distribution on the instrument panel 5 based on the signal from the illuminance sensor 7.

  In step S102, the overall brightness determination unit 31 refers to the overall brightness DB 32 based on the illuminance distribution or the average illuminance, and determines the overall brightness of the instrument panel 5. In step S103, the partial luminance determination unit 33 refers to the partial luminance DB 34 based on the illuminance distribution and determines a partial luminance correction amount for correcting the overall luminance. In the present embodiment, the correction amount is determined in this way. However, a partial luminance for an appropriate part on the instrument panel 5 may be determined, and this part may be used with priority over the entire luminance.

  In step S104, the luminance of the instrument panel 5 is corrected based on the overall luminance determined in step S102 and the partial luminance correction amount determined in step S103.

  As described above, the processing from step S101 to step S104 is repeated as needed until it is determined in step S105 that the image display apparatus has been stopped due to power-off or the like. By repeating this process, an image on the instrument panel 5 is obtained with high visibility despite the influence of the incident light 3.

  In the first embodiment described above, the overall luminance determining unit 31 and the partial luminance determining unit 32 are provided, and the overall luminance and the partial luminance are determined in each. However, the present invention uses the illuminance distribution on the display screen as the luminance. It may be characterized by the fact that it is used for the determination, and it may determine either the overall luminance or the partial luminance.

  In the first embodiment, only the luminance has been described as the correction item for the instrument panel 5. However, the present invention is not limited to the adjustment of the luminance, and may be changed to appropriately adjust the contrast of the region. Both brightness and contrast may be adjusted, or at least one of brightness and contrast may be adjusted.

  Next, a second embodiment of the present invention will be described. In this embodiment, the method for obtaining the illuminance distribution is different from that in the first embodiment, and the description of similar parts is omitted, and the description is changed to the description in the first embodiment.

  FIG. 6 shows a system configuration of the entire vehicle 1, where 1 is a vehicle as a host vehicle, 20 is an instrument panel incident light state determination ECU, and 30 is an instrument panel brightness adjustment ECU similar to that of the first embodiment.

  The in-vehicle camera 8 (imaging means) installed in the vehicle 1 includes a front camera 81 (front imaging means) that images the front of the vehicle 1 for a drive recorder, and a rear camera that images the rear of the vehicle 1 for a back guide monitor. 82 (rear image pickup means), a side camera 83 (peripheral image pickup means) for around view, and the like. Each vehicle-mounted camera 8 images the surroundings of the vehicle 1 with a field of view based on the angle of view that the vehicle-mounted camera 8 has. In this embodiment, the existing in-vehicle camera 8 having such a photographing purpose is used. However, the in-vehicle camera 8 is separately used as a dedicated light source detection camera (light source imaging unit) for detecting the light source position. May be provided.

  The instrument panel incident light determination ECU 20 includes an image analysis unit 22, an illuminance distribution prediction unit 23, a vehicle shape DB 24 that is a vehicle shape, and the like. The image analysis unit 22 analyzes an image captured by the in-vehicle camera 8 and specifies a position with high luminance such as the sun or a streetlight as the position of the light source 2 in the image. For example, it is specified by the position in the image where the luminance is equal to or higher than the threshold value. When photographing a light source 2 with high brightness such as the sun, it may be difficult to specify the light source position, and the shutter speed of the in-vehicle camera 8 and the lens aperture may be adjusted so that the light source position can be specified. May be.

  Further, the intensity of light from the light source 2 may be calculated from an image photographed including the light source 2. This light intensity is calculated using the luminance at the position of the image determined as the light source position. When the shutter speed of the in-vehicle camera 8 and the lens aperture are adjusted, the intensity is calculated in consideration of the adjusted shutter speed and aperture.

  The illuminance distribution prediction unit 23 calculates the illuminance distribution of the incident light 3 inserted into the instrument panel 5 from the position of the light source 2 in the image and the light intensity of the light source 2 analyzed by the image analysis unit 22. That is, since the in-vehicle camera 8 is fixedly installed in the vehicle, the incident angle of the incident light 3 with respect to the vehicle 1 can be determined by using the light source position in the image acquired by the image analysis unit 22. Based on the incident angle and the own vehicle shape stored in the own vehicle shape DB, it is possible to predict an illuminance distribution composed of a portion where the incident light 3 strikes and a portion where the incident light 3 does not strike on the surface of the instrument panel 5.

  Furthermore, if the intensity of light is calculated from an image taken by the in-vehicle camera 8, the intensity of light in each of the incident light 3 and non-contact parts can be predicted. In the second embodiment, the illuminance distribution based on the image captured by the in-vehicle camera 8 is used as described above.

  FIG. 7 shows an embodiment in which a wide-angle lens is used for the in-vehicle camera 6 and shows a state where the light source 2 has a field of view A. If an image is taken in this state, an image in which the light source 2 enters the visual field A can be acquired. The acquired image is analyzed by the instrument panel incident light state determination ECU 20, and the illuminance distribution is calculated.

  The luminance correction process performed based on the main configuration of the second embodiment described above will be described. FIG. 8 is a diagram showing a flow of luminance correction processing.

  When the power of the image display device is turned on, the luminance correction process is started (step S200). In step S201, it is detected whether or not the light source 2 is in the image captured by the in-vehicle camera 8. In the case where a plurality of in-vehicle cameras 8 are provided, the light source 2 may be included in an image captured by any one of the in-vehicle cameras 8. Further, whether or not the light source 2 is included is determined by the image analysis unit 21 as described above.

  If it is determined that the light source 2 is present in the image, the position and light intensity of the light source 2 are detected in step S202. In the present invention, since the illuminance distribution can be calculated by detecting at least the position of the light source 2, the detection of the light intensity is performed in an auxiliary manner. In steps S203 and S204, the illuminance distribution prediction unit 23 calculates the incident angle of light with respect to the vehicle 1 and predicts the illuminance distribution on the surface of the instrument panel 5.

Through the above processing, the illuminance distribution on the surface of the instrument panel 5 that is characteristic in the second embodiment is predicted. In step S205 to step S207, the same processing as in step 102 to step S104 in the first embodiment is performed using this illuminance distribution.
The brightness of the instrument panel 5 is corrected. The processing from step S201 to step S207 is repeated as needed until it is determined in step S208 that the image display apparatus has been stopped due to power-off or the like. By repeating this process, an image on the instrument panel 5 with high visibility can be obtained despite the influence of the incident light 3.

  As described above, according to the present invention, in an image display device used under a strong light source, it is possible to adjust the luminance or contrast of the screen using the illuminance distribution on the screen, and the screen with high visibility. Can be provided. In the present invention, adjusting the lighting effect changes the lighting effect for an image having a predetermined lighting effect even if the lighting effect is applied to an image for which the predetermined lighting effect has not been made. Even if it is a thing, adjusting lighting is applicable to what performs lighting, and is not limited only to this embodiment.

  In addition, the problem of visibility in the flat panel that the present invention solves is not only a display display device in the vehicle such as an instrument panel, but also a notebook personal computer and various information terminal devices that will be used outdoors in the future, This is also common in various image display devices that are exposed indoors to a strong light source. Therefore, the present invention is applicable not only to an image display device in a vehicle but also to various image display devices.

The figure which showed the mode of the insertion of the light in the vehicle exterior. The figure which showed the mode of the insertion of the light inside a vehicle. The figure which showed the main structures of the image display apparatus of this invention. The figure which showed the illumination intensity sensor installed on an instrument panel. The figure which showed the flow of the brightness correction process of this invention. The figure which showed the main structures of the image display apparatus of other embodiment of this invention. The figure which showed the mode of the light source imaging | photography with the vehicle-mounted camera of this invention. The figure which showed the flow of the brightness | luminance correction of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Light source, 3 ... Incident light, 4 ... Driver's seat, 5 ... Instrument panel, 6 ... Transparent illumination sensor cell, 7 ... Illuminance sensor, 8 ... In-vehicle camera, 81 ... Front camera, 82 ... Rear camera, DESCRIPTION OF SYMBOLS 83 ... Side camera, 9 ... Angle of view, 20 ... Instrument panel incident light state discrimination | determination ECU, 21 ... Illuminance distribution discrimination | determination part, 22 ... Image analysis part, 23 ... Illuminance distribution prediction part, 24 ... Own vehicle shape DB, 30 ... Instrument panel brightness | luminance Adjustment ECU, 31... Overall brightness determination unit, 32... Overall brightness DB, 33... Partial brightness determination unit, 34.

Claims (3)

Image display means for displaying an image;
Detection means for detecting the illuminance distribution on the surface of the image display means;
An image display apparatus comprising: an adjustment unit that adjusts at least one of luminance and / or contrast of the image display unit based on the illuminance distribution detected by the detection unit. The image display apparatus according to claim 1, wherein the adjustment unit adjusts at least one of luminance and / or contrast of the entire image display unit. The image display device according to claim 1, wherein the adjustment unit adjusts at least one of partial luminance and contrast of the image display unit.

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