JP2006227332A - Display device, control method, control program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a video display device in which the setting of a display screen depending on surrounding brightness is changed according to a kind of a video signal. <P>SOLUTION: The video display device which is selectively inputted with either of a plurality of kinds of video signals and can display videos in a display element based on the video signal is equipped with an illuminance detection means 2 for detecting the illuminance of the display element, a signal discrimination means 51 for discriminating specific kinds of the video signals, and a display characteristic control means 52 for controlling the γ correction characteristics of the video signals based on the detected illuminance. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a display device, a control method thereof, a control program, and a recording medium.

  In recent years, display devices such as liquid crystal screens have been used in various places. In these display devices, the ambient light may be too bright, or the ambient light may be reflected on the display screen of the display device, making it difficult to see the display image displayed on the display screen. In such a case, the visibility of the display image displayed on the display screen can be improved by operating the brightness and contrast settings of the display screen and setting the display screen brightly.

  However, if the display screen is set to be bright, the display screen is too bright when the surroundings become dark, so this time it has been necessary to reset the display screen to dark.

Since it is troublesome to perform such an operation every time, an illuminance sensor is provided in the display device, and the display screen brightness, contrast, and γ correction are set according to the ambient illuminance detected by the illuminance sensor. A device has been devised. Thereby, the setting change of a display screen can be performed, without operating a display apparatus (for example, refer patent document 1).
JP-A-6-83287

  However, in the above-described conventional technique, the setting of the display screen is changed regardless of the type of the video signal. Therefore, the fidelity of the demodulated image is impaired in the image by the composite signal such as the television image.

  The present invention has been made in view of the above-described circumstances, and provides a video display device capable of changing the setting of a display screen in accordance with the ambient brightness in accordance with the type of video signal. Objective.

  The present invention detects an illuminance of the display unit in a video display device capable of selectively displaying any of a plurality of types of video signals and displaying the video on the display unit based on the input video signals. Illuminance detection means, signal discrimination means for discriminating a specific type of video signal, and display for controlling the γ correction characteristics of the video signal based on the detected illuminance when the specific video signal is input And a characteristic control means.

  In this case, the display characteristic control means may switch a γ correction value for the video signal when controlling the γ correction characteristic of the video signal. The specific type of video signal may be an RGB signal. The correction value may be a low illuminance γ correction value that is a γ correction value when the illuminance is low and a high illuminance γ correction value when the illuminance is high. The display characteristic control unit may switch the γ correction value by comparing a predetermined reference illuminance with the illuminance of the display unit.

  Further, the present invention provides a control method for controlling a video display device capable of selectively displaying any of a plurality of types of video signals and displaying a video on a display unit based on the input video signals. Control the γ correction characteristics of the video signal based on the process of detecting the illuminance of the display unit, the process of discriminating a specific type of video signal, and the illuminance detected when the specific video signal is input And a process of performing.

  In addition, the present invention provides a control program for controlling, by a computer, a video display device that can selectively input any of a plurality of types of video signals and display a video on a display unit based on the input video signals. The illuminance of the video signal is detected, the specific type of video signal is discriminated, and the γ correction characteristic of the video signal is controlled based on the illuminance detected when the specific video signal is input. It is characterized by that.

  The present invention is also characterized in that the control program is recorded on a computer-readable recording medium.

  According to the present invention, it is possible to change the setting of the display screen in accordance with the surrounding brightness by determining the display video according to the display video.

  Embodiments of the present invention will be described below with reference to the drawings.

[1] First Embodiment FIG. 1 is a perspective view showing an external configuration of a navigation apparatus 1 according to the present embodiment.
As shown in FIG. 1, the navigation device 1 includes a device main body 10 that is fitted in a predetermined storage space provided on a dashboard of a vehicle, and an operation panel 11 provided in front of the device main body 10. . The operation panel 11 includes a face panel 12 as a frame, a plurality of operation switches provided on the face panel 12, an operation panel open / close button (open / TILT key) 13, and a display panel fitted into the face panel 12. 14. The display panel 14 displays a map around the current location, the current location of the vehicle, and a route to the destination, thereby providing route guidance.

FIG. 2 is a block diagram showing the main configuration of the navigation device 1.
The navigation apparatus 1 includes an MPU (connection control means) 30. The MPU 30 centrally controls each part of the navigation apparatus 1. The MPU 30 includes an MD (Mini Disk) and a CD (Compact Disk). Alternatively, a recording medium reading unit 31 for reading a DVD (Digital Video Disk) or the like is connected.
The recording medium loaded in the recording medium reading unit 31 is accessed by the MPU 30, and the MPU 30 reads various data (music data and the like) recorded on the recording medium.

  The MPU 30 is connected to a RAM 33 for temporarily storing data read from the recording medium reading unit 31 and a sub MPU 34. The sub MPU 34 includes a ROM that stores various data such as a control program, a RAM that temporarily stores data, and a CPU that performs various controls based on the program and data stored in the ROM. Then, display control of the display panel 14 is performed.

The sound output unit 39 outputs music and audio under the control of the sub MPU 34. For example, in the reproduction of music data recorded on a recording medium, the music data read by the recording medium reading unit 31 Is output to the sound output unit 39 to reproduce the music.
The display unit 40 displays various information such as a map under the control of the sub MPU 34, and includes a drawing circuit 41, a liquid crystal driving circuit 43, and the liquid crystal panel 27 described above.

  The drawing circuit 41 receives a drawing command DSS including map data from the sub MPU 34 and controls the liquid crystal driving circuit 43 to perform display based on the drawing command DSS. The drawing circuit 41 includes a drawing processor, a VRAM (Video RAM), and the like. The LCD image processing circuit 50 and the γ correction circuit 3 are provided. The drawing processor generates drawing data (for example, bitmap image data) to be displayed on the liquid crystal panel 27 based on the drawing command DSS, and the VRAM holds the drawing data. The liquid crystal drive circuit 43 sequentially receives the drawing data held in the VRAM and displays it on the liquid crystal panel 27 based on the drawing data. The drawing circuit 41 and the liquid crystal driving circuit 43 are mounted on a liquid crystal driving circuit substrate constituting the display panel 14.

  The GPS (Global Positioning System) unit 44 includes an antenna (or a receiver) that receives GPS radio waves transmitted from GPS satellites. Based on the GPS radio waves, position coordinates indicating the current position of the vehicle, a traveling direction, Is output to the sub MPU 34 as the position detection signal PS. The sub MPU 34 searches for a guidance route from the current point to the destination indicated by the position detection signal PS at the time of route search and displays the search result on the liquid crystal panel 27. Also, at the time of route guidance, the sub MPU 34 displays the position detection signal PS. Based on the above, the movement status of the current position is displayed on the liquid crystal panel 27 together with a map to provide route guidance.

  The tuner unit 45 is composed of an FM multiplex reception processing unit, a beacon reception processing unit, and a TV reception processing unit. The FM multiplex reception processing unit receives FM multiplex broadcast waves under the control of the sub MPU 34, and generates congestion and VICS information such as accidents and traffic restrictions and information such as weather forecasts are extracted and output to the sub MPU 34.

  The beacon reception processing unit constituting the tuner unit 45 receives VICS information (road traffic information) related to the road on which the vehicle is traveling under the control of the sub MPU 34 and outputs it to the sub MPU 34. The information such as the VICS information and the weather forecast is information relating to traffic, and is information that assists the driver in driving the vehicle. Such information will be referred to as travel assistance information in the following description. In the present embodiment, the FM multiplex reception processing unit and the beacon reception processing unit acquire character information indicating driving assistance information, and this character information is output to the sub MPU 34 when the driving assistance information is received. When displaying the driving assistance information on the liquid crystal panel 27, the sub MPU 34 generates a drawing command DSS based on the character information received from the FM multiplex reception processing unit or the beacon reception processing unit, and outputs the drawing command DSS to the liquid crystal panel 27. Then, the driving assistance information is displayed.

  The TV reception processing unit constituting the tuner unit 45 receives a TV (television) broadcast wave under the control of the sub MPU 34 and outputs TV video and TV audio to the sub MPU 34, not shown. A TV tuner circuit is provided. The TV video is displayed as a moving image on the liquid crystal panel 27, and the TV sound is output from the sound output unit 39.

  The operation unit 36 includes a switch operation unit and a touch panel operation unit. In addition to the operation switch described above, the switch operation unit includes a switch circuit board (not shown) that converts the operation of the operation switch into an electrical signal and outputs the switch signal SS to the sub MPU 34. In addition to the touch panel, the touch panel operation unit includes a touch panel circuit board (not shown) that converts the operation of the touch panel into an electrical signal and outputs the touch signal TS to the sub MPU 34. The touch signal TS includes coordinate information indicating an operation location on the surface of the touch panel, and thus, which operation button is operated by the sub MPU 34 among the operation buttons displayed on the liquid crystal panel 27. Can be identified.

FIG. 3 is a block diagram of the LCD video processing circuit 50 and the γ correction circuit 3 which constitute a part of the drawing circuit 41 described above.
Here, the reason why the γ correction circuit 3 is provided will be described.
The brightness of the display panel 14 changes exponentially without being directly proportional to the input voltage. When the input voltage is small, the brightness changes slowly, but when the input voltage is large, the brightness changes abruptly. Therefore, the γ correction circuit 3 is provided in the drawing circuit 41, and the relationship between the input voltage and the brightness is linearly corrected to faithfully reproduce the image.
The γ correction circuit 3 includes a γ correction value switching circuit 52, an RGB / CV switching control circuit 51, a γ correction voltage supply circuit 53, an illuminance sensor 2, an illuminance monitoring circuit 54, and an illuminance reference voltage circuit 55. Has been.

The LCD video processing circuit 50 is a processing circuit that performs video processing of RGB signals and composite signals included in the drawing command DSS sent from the sub MPU 34 to RGB for LCD.
The γ correction value switching circuit 52 is a switching circuit for switching a γ correction value when the LCD image processing circuit 50 performs γ correction.

The RGB / CV switching control circuit 51 is a control circuit that controls the switching of the γ correction value of the γ correction value switching circuit 52 in accordance with the RGB signal or the composite signal output from the sub MPU 34 to the LCD video processing circuit 50. is there.
The γ correction voltage supply circuit 53 generates a voltage corresponding to a preset normal γ correction value (low illuminance γ correction value) and external light γ correction value (high illuminance γ correction value), and a γ correction value switching circuit. 52 is a voltage supply circuit that supplies the γ correction voltage value generated in 52.

The illuminance monitoring circuit 54 is a monitoring circuit that compares the illuminance detected by the illuminance sensor 2 with a reference voltage corresponding to the reference illuminance preset in the illuminance reference voltage circuit 55 and monitors the illuminance.
The illuminance sensor 2 is installed in the vicinity of the display panel 14, and the illuminance monitoring circuit 54 monitors the illuminance of light incident near the display panel 14 in the vehicle compartment via the illuminance sensor 2. At this time, when the illuminance detected by the illuminance sensor 2 becomes equal to or higher than the incident illuminance preset in the illuminance reference voltage circuit 55, the illuminance monitoring circuit 54 sets the correction value for γ correction performed on the video signal to the external light γ. A control signal is transmitted to the γ correction value switching circuit 52 so as to switch to the correction value.

  When receiving a control signal from the illuminance monitoring circuit 54 so as to switch the γ correction value, the γ correction value switching circuit 52 receives the γ correction value voltage generated by the γ correction voltage supply circuit 53. When receiving the γ correction value voltage, the γ correction value switching circuit 52 transmits the γ correction value voltage to the LCD image processing circuit 50.

When the LCD image processing circuit 50 receives the γ correction value voltage, the image signal received by the LCD image processing circuit 50 is γ-corrected based on the received γ correction value voltage, and the γ-corrected video signal is converted to the LCD image signal. It transmits to the liquid crystal drive circuit 43 (FIG. 2) in RGB.
The liquid crystal drive circuit 43 that has received the γ-corrected video signal displays a video on the display panel 14 by displaying a video based on the video signal on the liquid crystal panel 27.

FIG. 4 is a graph showing how γ correction is performed by the γ correction circuit 3.
The input data on the horizontal axis is the luminance of the video signal input to the LCD video processing circuit 50, where 0 is white and 100 is black.
The output value on the vertical axis is the luminance of the dots actually displayed on the display panel 14.
The video signal input to the LCD video processing circuit 50 normally performs γ correction on the video signal indicated by the curve A based on the normal γ correction value. The liquid crystal panel 27 that has received the signal indicated by the curve A displays an image indicated by the curve B that is as close as possible to the original video signal input to the LCD video processing circuit 50 due to its γ characteristic.

However, when the image signal received by the LCD image processing circuit 50 is subjected to γ correction using the external light γ correction value, the image signal is subjected to γ correction as indicated by a curve C. The liquid crystal panel 27 that has received the signal indicated by the curve C displays an image having display characteristics as indicated by the curve D by the γ correction. The image shown on the curve D is an image in which the halftone is subtracted from the image shown on the curve B and the contrast is artificially increased.
This makes it easier to see the display image when the display image displayed on the display panel 14 is difficult to see due to reflection from the reflection on the display panel 14 in an environment where strong external light is incident on the vehicle interior. it can.

However, when such display characteristic control is also performed on composite signals such as TV images, the fidelity of demodulated images is often impaired. Therefore, correction based on the external light γ correction value is performed on RGB images such as navigation images. It applies only to video signals.
The discrimination based on the type of the video signal is controlled by the RGB / CV switching control circuit 51. When the LCD video processing circuit 50 receives the RGB signal, the γ correction value switching circuit 52 operates, but the composite signal When the signal is received, the γ correction based on the normal γ correction voltage value is always performed, and the LCD image processing circuit 50 transmits the image signal to the liquid crystal driving circuit 43.

[2] Second Embodiment FIG. 5 is a perspective view showing an external configuration of a monitor device 6 according to the present embodiment.
As shown in this figure, the monitor device 6 includes a monitor device body 62 fitted in a predetermined storage space provided on the dashboard of the vehicle, a face panel 63 provided on the front surface of the monitor device body 62, and a display. A panel 61 is provided. On the face panel 63, a plurality of operation switches 64 and a face panel display section (not shown) fitted in the face panel 63 are provided. The display panel 61 is attached to the monitor device main body 62 so as to be freely opened and closed, and an illuminance sensor 60 is disposed on the front surface. The monitor device 6 is connected to a device such as a navigation device, and displays an image based on a video signal such as an RGB signal or a composite signal output from the connected device on the display panel 61.

  The monitor device 6 incorporates a γ correction circuit 65 similar to that of the first embodiment, and when the monitor device 6 receives an RGB signal, the γ correction value switching circuit operates to adjust the illuminance detected by the illuminance sensor 60. In response, the video based on the received RGB signal is displayed on the display panel 61 by changing the γ correction value. When the monitor device 6 receives a composite signal, the monitor device 6 always performs γ correction based on the normal γ correction voltage value, and displays an image based on the received composite signal on the display panel 61.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to this. For example, although the in-vehicle display device is described in the embodiment, the display device is not limited to the on-vehicle device, but may be other display devices such as a personal computer monitor.

It is a perspective view which shows the external appearance structure of the navigation apparatus which concerns on embodiment of this invention. It is a block diagram which shows the functional structure of the said navigation apparatus. It is a block diagram which shows the function structure of the video processing circuit for LCD, and a (gamma) correction circuit. It is the graph which showed the mode of (gamma) correction by (gamma) correction circuit. It is a figure equivalent to FIG. 1 in 2nd Embodiment.

Explanation of symbols

1 Navigation device (video display device)
2 Illuminance sensor (illuminance detection means)
6 Monitor device (video display device)
14 Display panel (display unit)
51 RGB / CV switching control circuit (signal discrimination means)
52 γ correction value switching circuit (display characteristic control means)

Claims (8)

In a video display device capable of selectively displaying one of a plurality of types of video signals and displaying a video on a display unit based on the input video signal,
Illuminance detection means for detecting the illuminance of the display unit;
Signal discriminating means for discriminating a specific type of video signal;
Display characteristic control means for controlling a γ correction characteristic of the video signal based on the detected illuminance when the specific video signal is input;
A video display device comprising:   2. The video display apparatus according to claim 1, wherein the display characteristic control means switches a gamma correction value for the video signal when controlling the gamma correction characteristic of the video signal.   The video display device according to claim 1, wherein the specific type of video signal is an RGB signal.   The correction value is a low illuminance γ correction value that is a γ correction value when the illuminance is low and a high illuminance γ correction value when the illuminance is high. Video display device.   5. The video display device according to claim 1, wherein the display characteristic control unit switches the γ correction value by comparing a predetermined reference illuminance with an illuminance of the display unit. 6. In a control method for controlling a video display device capable of selectively displaying one of a plurality of types of video signals and displaying a video on a display unit based on the input video signal,
Detecting the illuminance of the display unit;
The process of discriminating specific types of video signals,
Controlling a γ correction characteristic of the video signal based on the illuminance detected when the specific video signal is input;
A method for controlling a video display device, comprising: In a control program in which one of a plurality of types of video signals is selectively input and a video display device capable of displaying video on a display unit based on the input video signal is controlled by a computer,
Illuminance of the display unit is detected,
Make certain types of video signals distinct,
A control program for controlling a γ correction characteristic of the video signal based on the illuminance detected when the specific video signal is input. A computer-readable recording medium having the control program according to claim 7 recorded thereon.

Images