JPH05145872A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To automatically display a specific image in a stand-by state. CONSTITUTION:When the stand-by state is indicated through the operation of a stand-by switch part 9, a microcomputer part 2 controls an image selector part 3 to selectively supply the video signal from an image decoding part 6 to a liquid crystal display part 1. The image decoding part 6 converts image data stored on a memory card into a video signal and the image stored on the memory card is displayed at a liquid crystal display part 1. When the periphery reaches specified darkness, the microcomputer part 2 powers OFF the liquid crystal display part 1 with the detection signal from an optical sensor part 10 and stops the screen display.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device suitable for a wall-mounted type.

[0002]

2. Description of the Related Art At present, a cathode ray tube is predominantly used as a display device for a television receiver because of its high brightness and high resolution. In recent years, along with the development of liquid crystal panels, liquid crystal display devices that were originally used for calculators and wrist watches have come to be adopted as display devices for television receivers and the like. The liquid crystal display device has the advantages that it is smaller and lighter in weight and consumes less power than a cathode ray tube, and that no burn-in occurs even when the same pattern is displayed for a long time.
Taking advantage of these advantages, the liquid crystal display device is used for a television receiver for a vehicle or a wall.

A liquid crystal display panel of a conventional liquid crystal display device has pixels arranged in a matrix and drives by supplying a scanning signal and a video signal to each pixel. That is, each pixel is turned on by the scanning signal, and a video signal is supplied to each turned-on pixel to change the light transmittance.
The light transmission of the liquid crystal layer is based on the image, and the image is displayed on the display surface.

Therefore, when no video signal is supplied, the light transmittance of the display surface is uniform, and the light transmittance is the highest or the lowest. That is, in the conventional liquid crystal display device, when the received signal from the television tuner or the external video signal is not input, the entire screen is normally displayed in black. When such a television signal is not input (hereinafter referred to as a standby state), turn off the power source of the backlight,
The screen display is stopped.

However, when the screen display is stopped, the entire screen becomes a color such as blue black, giving an extremely dark feeling. In particular, when it is used for hanging on a wall, a dark color display surface appears at the eye level of the wall, and the effect as an interior is extremely low. Therefore, in addition to the function as the television receiving device, in order to maintain the effect as the interior, for example, when the supply of the television signal is stopped, the input is switched to the external video signal and the supply of the external video signal is stopped. In addition, complicated operations such as preparing another external video signal input are required.

[0006]

As described above, in the above-mentioned conventional liquid crystal display device, it is advantageous to display for a long time as an interior as compared with a cathode ray tube because of low power consumption and no image sticking. However, in order to take advantage of this advantage and perform continuous display, there is a problem that complicated video input switching is required.

The present invention makes it possible to automatically display a predetermined image in the standby state.
An object of the present invention is to provide a liquid crystal display device capable of improving its function.

[0008]

A liquid crystal display device according to the present invention comprises a reading means for reading the image data from a storage device storing the image data, decoding the image data and outputting a video signal, and a video signal from the reading means. Selecting means for selecting one of a plurality of video signals including
A liquid crystal display section for displaying a screen by receiving a video signal from the selecting means, and a standby state instructing the selecting means to select the video signal from the reading means, and the ambient light amount in the standby state is a predetermined value. The control means for turning off the power source of the liquid crystal display unit to stop the screen display when the temperature falls below the range.

[0009]

In the present invention, the reading means reads the image data stored in the storage device and outputs a video signal. When the standby state is instructed, the control means causes the selection means to select the video signal from the reading means and supplies it to the liquid crystal display section. The liquid crystal display is controlled to be turned on and off by the control means, and the power is not turned off even when the standby state is instructed. Accordingly, in the standby state, for example, a still image stored in the storage device is displayed. When the control means determines that there is no viewer by the decrease in the amount of ambient light,
Turn off the power to the LCD display to stop the screen display.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a liquid crystal display device according to the present invention.

The liquid crystal display unit 1 has pixels arranged in a matrix, and a video signal is supplied to each pixel to display an image on a display screen.
The liquid crystal display unit 1 receives the video signal from the image selector unit 3. A microcomputer (hereinafter referred to as a microcomputer) unit 2 supplies a power supply control signal to the liquid crystal display unit 1 to control power on / off.

The image selector section 3 inputs a video signal from the TV tuner section 4, the external video input section 5 and the image decoding section 6. The image selector unit 3 is controlled by the select signal from the microcomputer unit 2, selects any one of the input video signals, and outputs it to the liquid crystal display unit 1. The TV tuner unit 4 receives an RF (high frequency) signal or the like from an antenna (not shown), selects a signal of a desired channel, demodulates it, and supplies it to the image selector unit 3. Further, the external video input section 5 receives a video signal from an external device such as a video tape recorder (not shown),
It is given to the image selector unit 3. Further, in this embodiment, a video signal based on the image data stored in the storage device is also given to the image selector section 3.

That is, compressed image data of a predetermined still image is stored in a memory card (not shown). The IC card input unit 7 reads the compressed image data stored in the memory card and gives it to the image decoding unit 6. The image decoding unit 6 decodes the read compressed image data and gives a video signal to the image selector unit 3.

The TV key unit 8 is provided with various keys (not shown) and outputs a signal based on a user's key operation to the microcomputer unit 2. The standby switch unit 9 is provided with a standby switch (not shown) for instructing a standby state, and a signal based on the operation of this switch is given to the microcomputer unit 2. The optical sensor unit 10 detects the amount of light in the surroundings and gives a detection signal to the microcomputer unit 2 indicating that the surroundings have become relatively dark.

The microcomputer section 2 controls the channel selection of the TV tuner section 4 based on the user operation of the TV key section 8 and outputs a select signal for selecting a video signal to the image selector section 3. When the standby state of the standby switch unit 9 is instructed by the standby switch unit 9, the microcomputer 2 outputs to the image selector unit 3 a select signal for selecting the video signal from the image decoding unit 6. Until the detection signal indicating that the surroundings are relatively dark is input from the optical sensor unit 10, the power supply control signal keeps the liquid crystal display unit 1 in the power-on state.

Next, the operation of the embodiment thus constructed will be described with reference to FIG. Figure 2 shows the microcomputer section 2
It is a flowchart which shows the process in the standby state.

When the power is turned on, the TV tuner unit 4 or the external video input unit 5 is displayed on the liquid crystal display unit 1 as in the conventional case.
An image based on the video signal from is displayed. That is, when the reception of the television signal is instructed by the user operation of the TV key unit 8, the TV tuner unit 4 selects the channel based on the user operation and demodulates it. The microcomputer unit 2 gives a select signal for selecting the TV tuner unit 4 to the image selector unit 3,
The video signal demodulated by the TV tuner unit 4 is given to the liquid crystal display unit 1 via the image selector unit 3. The liquid crystal display unit 1 drives each pixel based on the input video signal to display the image of the reception channel on the display screen.

On the other hand, when the external video input section 5 is selected by operating the TV key section 8, the microcomputer section 2 gives a select signal to the image selector section 3 to select the external video input section 5. Let As a result, the video signal from the external device is given to the liquid crystal display unit 1 via the external video input unit 5 and the image selector unit 3. The liquid crystal display unit 1 drives each pixel based on an external video signal to display an image on the display screen based on a video signal from an external device.

Here, it is assumed that the user operates the standby switch of the standby switch unit 9 to instruct the standby state. Then, in step S1 of FIG. 2, the microcomputer 2 outputs a select signal for selecting the output of the image decoding unit 6 to the image selector unit 3 with the liquid crystal display unit 1 powered on. The IC card input unit 7 specifies a predetermined address of the memory card based on a user operation, reads desired still image compressed image data, and supplies it to the image decoding unit 6. The image decoding unit 6 decodes the input image data, converts it into a video signal, and outputs it to the image selector unit 3. The image selector section 3 selects the video signal from the image decoding section 6 and supplies it to the liquid crystal display section 1.

The liquid crystal display unit 1 receives a still image video signal from the image selector unit 3 and drives each pixel based on the video signal to display a still image on the display screen. Thereafter, this video signal is continuously supplied, and the still image display is continued. In the next step S2, the microcomputer unit 2 determines whether or not the surroundings have become dark based on the presence or absence of the detection signal from the optical sensor unit 10. For example, when the surroundings are bright due to indoor lighting, etc., in the next step S3, the power of the liquid crystal display unit 1 is maintained in the ON state and the still image is continuously displayed. Shall be dark. The optical sensor unit 10 detects the amount of ambient light and outputs a detection signal to the microcomputer unit 2 when the surroundings become dark. Then, the microcomputer section 2 shifts the processing from step S2 to step S4 and turns off the power source of the liquid crystal display section 1 by the power source control signal. As a result, the screen display of the liquid crystal display unit 1 is stopped.

As described above, in this embodiment, when the user operates the standby switch section 9 to instruct the standby state, the data is read from the memory card in which the compressed image data of the still image is stored. , Liquid crystal display 1
Since the still image is displayed on the screen, the function as the interior can be added without requiring a complicated operation. Further, the screen display is stopped by determining that no one is looking at the screen based on the amount of ambient light, which is also advantageous in that the power saving effect is high.

Although a memory card is used as the storage device in this embodiment, another recording medium may be used.

[0023]

As described above, according to the present invention, a predetermined image can be automatically displayed in the standby state.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the embodiment.

[Explanation of symbols]

1 ... Liquid crystal display section, 2 ... Microcomputer section, 3 ... Image selector section, 4 ... TV tuner section, 5 ... External video input section, 6 ...
Image decoding unit, 7 ... IC card input unit, 9 ... Standby switch unit

Claims (1)

[Claims] 1. A reading means for reading the image data from a storage device storing the image data, decoding the image data and outputting a video signal, and selecting one of a plurality of video signals including the video signal from the reading means. Selecting means, a liquid crystal display section for displaying a screen by receiving a video signal from the selecting means, and when the standby state is instructed, the selecting means is caused to select the video signal from the reading means, and in the standby state A liquid crystal display device comprising: a control means for turning off the power source of the liquid crystal display unit to stop the screen display when the amount of ambient light drops below a predetermined value.