JP2007086370A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device for achieving an image output circuit in a comparatively low cost and simple configuration for outputting image signals having different signal types to a display panel in the so-called multi-view display device. <P>SOLUTION: The display panel has an image output circuit for outputting a temporarily holding CV signal or an EGA signal to a liquid crystal panel 110 by temporarily holding the CV signal or the EGA signal out of a WVGA signal and the CV signal or the EGA signal input at different timing and being matched with output timing to the liquid crystal panel 110 of the WVGA signal. Thereby the output circuit for outputting the WVGA signal and the CV signal or the EGA signal on the liquid crystal panel 110 is made common to reduce circuit scale. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a display device that can visually recognize different images from different directions on a common display panel.

As a multi-view display device capable of visually recognizing images from different directions on a common display screen, for example, a parallax barrier is provided in front of the liquid crystal panel, and the traveling direction of light from the backlight is distributed for each pixel. One that can display different information (images) on the left and right is known (see, for example, Patent Document 1). By mounting such a display device on the vehicle, the passenger in the passenger seat can watch other images such as a television while the driver is watching the navigation image.
JP 2005-78080 A

By the way, in the multi-view display device as described above, for example, when different images are displayed on the driver side screen and the passenger side screen, respectively, a composite video signal composed of NTSC or PAL, EGA (Enhanced Graphics Adapter) It is necessary to select an image signal of a desired format from image signals having different signal formats such as a signal and a WVGA (Wide Video Graphics Array) signal and output the selected image signal to a display panel such as a liquid crystal panel.
However, image signals having different signal formats as described above have different resolutions and input timings. In order to display these image signals at the same time, if an image output circuit for displaying an image on the display panel is formed independently for each signal format, the circuit scale increases and the device cost also increases.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a relatively low image output circuit for outputting image signals having different signal formats to a display panel in a so-called multi-view display device. An object of the present invention is to provide a display device that is realized at a low cost and with a simple configuration.

The display device according to the present invention displays the first and second images by outputting the first and second image signals to a common display panel having first and second screens that can be viewed from different fields of view. An image output circuit that holds the second image signal and outputs the second image signal held in accordance with the output timing of the first image signal to the display panel, to the display panel. It is characterized by having.
According to this configuration, the second image signal can be output to the display panel in synchronization with the output timing of the first image signal to the display panel by holding the second image signal. The output circuit for outputting the second image signal can be shared, and the circuit scale can be reduced. Further, since only the second image signal is held and the first image signal is output to the display panel as it is, the output timings of signals having different input timings can be matched with the minimum necessary memory capacity.

In the above configuration, the image output circuit may include a first resolution changing circuit that changes the resolution of the first image signal so as to match the screen resolution of the display panel. The image output circuit has a second resolution change circuit that changes the resolution of the second image signal so as to match the resolution of the screen of the display panel, separately from the first resolution change circuit. Can be adopted.
According to this configuration, the circuit configuration of each resolution changing circuit can be simplified by independently changing the resolution of the first image signal and the second image signal input at different timings.

In the above configuration, the image output circuit is formed so as to be able to selectively input an image signal of a different signal format as the second image signal, and the second resolution changing circuit has the second resolution signal in accordance with each signal format. A configuration in which the resolution of the image signal can be changed can be employed.
According to this configuration, since the second resolution changing circuit to which image signals having different signal formats are selectively input is used in common for different signal formats, the circuit scale can be reduced.

  According to the present invention, in a so-called multi-view display device, an image output circuit that outputs image signals having different signal formats to a display panel can be realized at a relatively low cost and with a simple configuration.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
FIG. 1 is a diagram for explaining a basic configuration of an in-vehicle dual view display device according to an embodiment of the present invention.
As shown in FIG. 1, the in-vehicle dual view display device includes a display control unit 10, a display unit 100 as a display panel, image sources 300A and 300B, and the like.
The display control unit 10 is supplied with the image data (image signal) DT1 from the first image source 300A and the image data (image signal) DT2 from the second image source 300B. The image data (image signal) ADT composed of the image data DT 1 and DT 2 is output to the common display unit 100. A specific configuration of the display control unit 10 will be described later.
The first and second image sources 300A and 300B are composed of a plurality of sources such as a camera, a TV receiving unit, a DVD playback unit, an HD playback unit, and a navigation unit, which will be described later.

  As will be described later, the display unit 100 includes a liquid crystal panel, a backlight, a parallax barrier, and the like, and the first image IM1 based on the first image data DT1 can be viewed from the right by the observer OBR. The second image IM2 based on the second image data DT2 is displayed on the common display screen so that the observer OBL can visually recognize from the left direction. A specific configuration of the display unit 100 will be described later.

FIG. 2 is an external perspective view of a display device according to an embodiment of the present invention, and FIG. 3 is a perspective view illustrating an example of mounting on a vehicle according to an embodiment of the present invention.
The apparatus main body 100A of the display device shown in FIG. 2 is built in the dashboard portion of the vehicle, and the display unit 100 is disposed between the driver seat DS and the passenger seat AS as shown in FIG. The display unit 100 is provided with an operation unit 150 for manually operating the display device.
In the case shown in FIG. 3, the occupant seated in the driver seat DS is the observer OBR, and the occupant seated in the passenger seat AS is the observer OBL. These passengers can simultaneously view different first images IM1 and second images IM2 displayed on the display unit 100 from the driver seat DS side or the passenger seat AS side, respectively.

  4 to 8 are diagrams showing a specific configuration of the display device according to the embodiment of the present invention. FIG. 4 is a functional block diagram of the display device, and FIG. 5 is a cross-sectional structure and operation of the liquid crystal panel. FIG. 6 is a front view of the liquid crystal panel, FIG. 7 is a circuit diagram of the TFT substrate, and FIG. 8 is a functional block diagram of the image output unit.

  As shown in FIG. 4, the display device includes a display unit 100, a control unit 20, a distribution circuit 30, first and second image quality adjustment circuits 50A and 50B, an image output unit 70 as an image output circuit, and the like. It is configured. The display control unit 10 includes a control unit 20, a distribution circuit 30, first and second image quality adjustment circuits 50A and 50B, an image output unit 70, and the like.

The control unit 20 includes a processor (CPU), an interface circuit, a ROM, a RAM, and the like, and comprehensively controls the display device according to a program stored in the ROM.
Further, as shown in FIG. 4, the control unit 20 is equipped with a camera 310 that images the surroundings of the vehicle as a supply source that is mounted on the vehicle and supplies images and sounds, and an MD (mini disc) that reproduces music and images. ) Playback unit 320, radio reception unit 330 that receives radio broadcast waves from an antenna, TV reception unit 340 that receives TV broadcast waves from an antenna via a selector 341, CD (compact disc) and DVD (digital versatile disc) CD / DVD playback unit 350 for playing back music information and images from HD, HD playback unit 360 for playing back images and music information recorded on HD (hard disk), road information and GPS information receiving unit received by VICS information receiving unit 371 A navigation unit 370 that outputs a map and a route guidance image based on the geographic information received by the 372, a semiconductor memo It is connected to the semiconductor memory reproduction unit 380 for reproducing the information stored on the card, controlling these together to exchange data between these.
Further, the control unit 20 includes a memory 140 for storing various data, an operation unit 150 for operating the display device, and a remote controller for transmitting and receiving infrared signals and radio signals to and from the remote control 171 for operating the display device by remote control. The transmission / reception unit 170, a brightness detection sensor 190 configured to detect the brightness in the vehicle by being configured with a light switch or a light sensor provided in the vehicle, a pressure-sensitive sensor provided in a driver seat or a passenger seat, and the like, An occupant detection sensor 200 to be detected is connected, and the control unit 20 can perform various controls based on various data obtained from these.

As shown in FIG. 4, the distribution circuit 30 is supplied from the camera 310, the MD playback unit 320, the radio reception unit 330, the TV reception unit 340, the CD / DVD playback unit 350, the HD playback unit 360, the navigation unit 370, and the like. Audio data and image data to be input are input. The navigation image data from the navigation unit 370 is output to the first image quality adjustment circuit 50A, and the other image data is output to the second image quality adjustment circuit 50B in response to a control command from the control unit 20. The The audio data is output to the audio adjustment circuit 60.
As shown in FIG. 4, the audio adjustment circuit 60 adjusts the audio data supplied from the distribution circuit 30 and outputs it to the speaker 61.

  The first and second image quality adjustment circuits 50A and 50B are each composed of a contrast adjustment unit, a luminance adjustment unit, a color tone adjustment unit, a gamma value adjustment unit, and the like, and according to a control command from the control unit 20, the first and second image quality adjustment circuits 50A and 50B. The image quality (contrast, brightness, color tone, gamma value) of the second image data is adjusted.

  As shown in FIG. 4, the display unit 100 includes a liquid crystal panel 110, a backlight 120 that illuminates illumination light from the back side of the liquid crystal panel 110, a touch panel 130 for inputting a signal for operating the display device, and the like. . Although not shown, the touch panel 130 is formed in a transparent sheet shape and attached to the front surface of the liquid crystal panel 110.

As shown in FIG. 5, the liquid crystal panel 110 includes a polarizing plate 111, a TFT (Thin Film Transistor) substrate 112, a liquid crystal layer 113, and a color filter substrate having pixels of three primary colors RGB arranged in order from the backlight 120 side. 114, a parallax barrier 115, a glass plate 116, a polarizing plate 117, and the like.
As shown in FIGS. 5 and 6, the liquid crystal panel 110 has a display screen in which, for example, 800 pixels in the horizontal direction and 480 pixels in the vertical direction are arranged. Pixels 118 (hereinafter also referred to as passenger seat side display pixels 118) and right side display pixels 119 (hereinafter also referred to as driver seat side display pixels 119) are alternately arranged.
Therefore, each of the driver's seat side display screen and the passenger seat side display screen has a resolution of 400 × 480 pixels.

As shown in FIGS. 5 and 6, the parallax barrier 115 is formed in a stripe shape and includes a shielding part and a light-transmitting part. The shielding part is formed by the adjacent left display pixel 118 and right display pixel 119. Arranged between. By disposing the parallax barrier 115 on the front surface of the color filter substrate 114, the illumination light transmitted through the left display pixel 118 selectively passes through the light-transmitting part of the parallax barrier 115 selectively toward the left side, and is displayed on the right side. Of the illumination light transmitted through the pixel 119, only the illumination light directed toward the right side selectively passes through the light transmitting portion of the parallax barrier 115. As a result, as shown in FIG. 5, the first image IM1 can be viewed from the right side (driver's seat side) of the liquid crystal panel 110, and the second image IM2 can be viewed from the left side (passenger seat side). ing.
The parallax barrier 115 can be the same as those disclosed in JP-A-10-123461 and JP-A-11-84131.

As shown in FIG. 7, the TFT substrate 112 includes a data line driving circuit DR1, a scanning line driving circuit DR2, scanning lines SCL arranged in the vertical direction, data lines DTL arranged in the horizontal direction, scanning lines SCL and data lines. A pixel electrode EP formed corresponding to the TFT element EL formed in each region intersecting with the DTL is provided, and each region surrounded by the scanning line SCL and the data line DTL constitutes a subpixel SBP. The subpixels SBP in each column along the data line DTL are alternately assigned to the left display pixel 118 and the right display pixel 119.
The data line driving circuit DR1 is controlled in its driving timing by the liquid crystal panel driving unit 74, and controls the voltage applied to the pixel electrode EP.
The scanning line driving circuit DR2 selectively scans the TFT element EL by controlling the driving timing by the liquid crystal panel driving unit 74.

  The memory 140 is configured by, for example, an electrically rewritable nonvolatile memory such as a flash memory or a battery-backed volatile memory, and stores data necessary for control by the control unit 20.

  As shown in FIG. 8, the image output unit 70 includes a plurality of AD (analog / digital) converters AD1 to AD7, a YC separation circuit 71, an RGB decoder 72, a switching circuit 73, and a resolution conversion as a second resolution changing circuit. Circuit 74, writing circuit 75, reading circuit 76, pixel interpolation circuit 77 as a first resolution changing circuit, output timing control circuit 78, memory IF 79, VRAM 80, C / B adjustment circuit 81, RGB rearrangement circuit 82, gamma The image output unit 70 includes a table 83, a gamma correction circuit 84, a TFT timing control circuit 85, and the like, and is formed by, for example, an ASIC (Application Specific Integrated Circuit).

The AD converter AD1 synchronizes the YC signal (luminance signal and color signal) of the CV (composite video) signal composed of the analog signal input from the second image quality adjustment circuit 50B in synchronization with the clock signal CLK1 (for example, 13 MHz). By sampling, it is converted into a digital signal, which is output to the YC separation circuit 71.
The CV signal has a resolution of 720 × 240 (dots) and is composed of a YC signal and a composite synchronization signal CSYNC1, and the composite synchronization signal CSYNC1 is also input to the image output unit 70. The composite synchronization signal CSYNC1 is a signal including a vertical synchronization signal component and a horizontal synchronization signal component. The CV signal is composed of an analog television signal from the TV receiver 340 and a signal obtained from the CD / DVD reproducing unit 350. Further, the clock signal CLK1 is supplied from a voltage controlled oscillator VCO1 provided outside the image output unit 70.

The AD converters AD2 to AD4 convert the R, G, and B signals of the EGA signal composed of analog signals input from the second image quality adjustment circuit 50B into digital signals by sampling in synchronization with the clock signal CLK1. This is output to the switching circuit 73.
The EGA signal has a resolution of 400 × 240 (dots) and is composed of R, G, B signals and a composite synchronization signal CSYNC2, and the composite synchronization signal CSYNC2 is also input to the image output unit 70. The composite synchronization signal CSYNC2 is a signal including a vertical synchronization signal component and a horizontal synchronization signal component. The EGA signal is a signal formed by resizing a DTV (digital television) signal obtained from the TV receiver 340, for example.

The AD converters AD5 to AD7 sample the R, G, and B signals of the WVGA signal that is an analog signal input from the first image quality adjustment circuit 50A in synchronization with the clock signal CLK2 (for example, 33.231 MHz). Convert to digital signal.
Note that the WVGA signal has a resolution of 800 × 480 (dots) and is obtained from the navigation unit 370, for example, an image signal for map display. The clock signal CLK2 is supplied from a voltage controlled oscillator VCO2 provided outside the image output unit 70.

The YC separation circuit 71 separates the YC signal of the CV signal into a Y (luminance) signal and a C (color) signal and outputs them to the RGB decoder 72.
The RGB decoder 72 converts the Y signal and C signal into R, G, B signals and outputs them to the switching circuit 73.
The switching circuit 73 selectively selects one of the R, G, B signals of the CV signal and the R, G, B signals of the EGA signal to the resolution conversion circuit 74 in accordance with the switching signal SEL input from the control unit 20. Output.

  The resolution conversion circuit 74 calculates the resolution of the R, G, and B signals of the CV signal or EGA signal so as to be the resolution (400 × 480) of the liquid crystal panel 110 and outputs it to the writing circuit 75. That is, the resolution conversion circuit 74 is formed so as to be able to change the resolution of the input image signal in accordance with each signal format.

  The VRAM 80 is a memory for temporarily holding R, G, B signals of CV signals or EGA signals, and for example, SDRAM (Synchronous DRAM) is used.

The write circuit 75 latches data (R, G, B signals) to be written to the VRAM 80 in synchronization with the composite sync signal CSYNC1 or CSYNC2 of the CV signal or EGA signal.
The read circuit 76 latches data read from the VRAM 80 at the output timing of the WVGA signal.

  The pixel interpolation circuit 77 performs pixel interpolation on the WVGA signal (R, G, B signal) having a resolution of 800 × 480, resizes it to a resolution of 400 × 480, and outputs it to the RGB rearrangement circuit 82. If the signal input from the first image quality adjustment circuit is a 400 × 480 VGA signal, this image interpolation circuit can be omitted.

The output timing control circuit 78 is a circuit that generates a timing for outputting an image to the display unit 100 (liquid crystal panel 110) based on the clock signal CLK2.
The memory IF 79 is a circuit that controls access to the VRAM 80 and writes the data latched in the write circuit 75 to the VRAM 80 in synchronization with the input timing of the CV signal or EGA signal, and in synchronization with the output timing of the WVGA signal. The data is read from the VRAM 80 and output to the C / B adjustment circuit 81.

  The C / B adjustment circuit 81 adjusts the image quality of the image composed of the R, G, and B signals of the CV signal or EGA signal temporarily held and read by the VRAM 80 and outputs the adjusted image quality to the RGB rearrangement circuit 82.

The RGB rearrangement circuit 82 rearranges the pixel data from the pixel interpolation circuit 77 and the C / B adjustment circuit 81 for two-screen display and outputs the rearranged pixel data to the gamma correction circuit 84.
The gamma correction circuit 84 is a circuit that linearly performs gamma correction in units of R, G, and B in accordance with the characteristics of the liquid crystal panel 110.
The gamma table 83 is a memory for holding a table value for gamma correction.
The TFT timing control circuit 85 is a circuit that outputs image data in accordance with the drive timing of a circuit formed on the TFT substrate 112 of the liquid crystal panel 110.

  As described above, the image output unit 70 temporarily holds the CV signal or the EGA signal among the WVGA signal and the CV signal or the EGA signal input at different timings in the VRAM 80 and transmits the WVGA signal to the liquid crystal panel 110. The CV signal or EGA signal temporarily held in the VRAM 80 is output to the liquid crystal panel 110 in accordance with the output timing.

According to the present embodiment, by temporarily holding the CV signal or EGA signal in the VRAM 80, the CV signal or EGA signal can also be output to the liquid crystal panel 110 in accordance with the output timing of the WVGA signal to the liquid crystal panel 110. The TFT timing control circuit 85 and the gamma correction circuit 84 as output circuits can be used in common, and an increase in the circuit scale of the image output unit 70 can be suppressed.
Further, since only a CV signal or an EGA signal is temporarily held in the VRAM 80 and a memory for temporarily holding the WVGA signal is not required, output timings of signals having different input timings with a minimum memory capacity are required. Can be matched.

  In the above embodiment, the case where a liquid crystal panel is used for the display unit 100 has been described. However, the present invention is not limited to this, and a flat panel display other than the liquid crystal panel, for example, an organic EL display panel, a plasma display panel, a cold cathode A flat panel display or the like can also be used.

  The above embodiment is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

It is a figure for demonstrating the basic composition of the display apparatus which concerns on one Embodiment of this invention. It is an external appearance perspective view of a display apparatus. It is a perspective view which shows the example of application to the vehicle of a display apparatus. It is a functional block diagram which shows the structure of a vehicle-mounted display apparatus. It is a figure which shows the cross-section of a display part. It is a front view of a liquid crystal panel. It is a circuit diagram of a TFT substrate. It is a functional block diagram which shows the structure of an image output part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Display control part 20 ... Control part 30 ... Distribution circuit 50A, 50B ... 1st and 2nd image quality adjustment circuit 60 ... Audio | voice adjustment circuit 70 ... Image output part 71 ... YC separation circuit 72 ... RGB decoder 73 ... Switching circuit 74 ... Resolution conversion circuit (second resolution change circuit)
75 ... Write circuit 76 ... Read circuit 77 ... Pixel interpolation circuit (first resolution changing circuit)
78 ... Output timing control circuit 79 ... Memory IF
80 ... VRAM
81 ... C / B adjustment circuit 82 ... RGB rearrangement circuit 83 ... Gamma table 84 ... Gamma correction circuit 85 ... TFT timing control circuit 100 ... Display unit (display panel)
DESCRIPTION OF SYMBOLS 100A ... Apparatus main body 110 ... Liquid crystal panel 120 ... Backlight 130 ... Touch panel 140 ... Memory 150 ... Operation part 170 ... Remote control transmission / reception part 190 ... Brightness detection sensor 200 ... Occupant detection sensor 300A, 300B ... Image source 310 ... Camera 320 ... MD Playback unit 330 ... Radio reception unit 340 ... TV reception unit 350 ... CD / DVD playback unit 360 ... HD playback unit 370 ... Navigation unit

Claims (5)

A display device for displaying first and second images by outputting first and second image signals to a common display panel having first and second screens that can be viewed from different fields of view, respectively.
An image output circuit for holding the second image signal and outputting the second image signal held in accordance with an output timing of the first image signal to the display panel; Characteristic display device.   The display according to claim 1, wherein the image output circuit includes a first resolution changing circuit that changes the resolution of the first image signal so as to match the resolution of the screen of the display panel. apparatus.   The image output circuit has a second resolution changing circuit that changes the resolution of the second image signal so as to match the resolution of the screen of the display panel, separately from the first resolution changing circuit. The display device according to claim 2. The image output circuit is formed so that an image signal of a different signal format can be selectively input as the second image signal,
The second resolution changing circuit is formed so as to be able to change the resolution of the second image signal in accordance with each signal format.
The display device according to claim 3.   5. The display device according to claim 1, wherein the first image signal is an image signal necessary for map display.

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