JP2003263136A - Liquid crystal projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal projector capable of displaying an on-screen image on an optimum position in accordance with a display mode. <P>SOLUTION: The liquid crystal display projector provided with a plurality of display modes having respectively different image writing sizes on a liquid crystal panel is also provided with a control means for controlling the display position of an on-screen image in accordance with the display mode. The control means controls the display position of the on-screen image in accordance with the display mode so that the on-screen image is located on the inside of a display image. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector.

[0002]

2. Description of the Related Art Some liquid crystal projectors have a function of displaying a setting screen or the like on-screen. In such a liquid crystal projector, the on-screen image is usually displayed at a predetermined position in the video display area.

By the way, in the image input to the liquid crystal projector, in addition to a normal image having an aspect ratio of 4: 3, among normal images having an aspect ratio of 4: 3, an aspect ratio in which there is no image at the upper and lower portions is 16 : There is also a landscape image of 9.

Therefore, the liquid crystal projector is provided with a display mode (normal mode) suitable for displaying a normal image and a display mode (full screen mode) suitable for displaying a landscape image. There is a mode in which the mode is switched by a user operation.
In such a liquid crystal projector, when the display position of the on-screen image is fixed at an optimum position for a certain display mode, the on-screen image may be displayed at an unfavorable position in other display modes. is there.

A description will be given of a liquid crystal projector having the above-mentioned two types of display modes, in which a liquid crystal panel has an aspect ratio of 16: 9 and an image is projected on a screen having an aspect ratio of 4: 3.

Here, a normal image having an aspect ratio of 4: 3 is an image as shown in FIG. 1A, and an aspect ratio of 16 :.
It is assumed that the horizontally long image 9 is an image as shown in FIG.

In the normal mode, a normal image having an aspect ratio of 4: 3 is written in the liquid crystal panel so that the vertical size matches the vertical size of the liquid crystal panel. Therefore, as shown in FIG. An image is written, leaving both the left and right sides of the liquid crystal panel P. Along with the aspect ratio of 16: 9, the aspect ratio is 4: 3 including the areas where there are no upper and lower images, and the aspect ratio is set to the LCD panel so that the aspect size matches the aspect size of the LCD panel. Since it is written, it becomes as shown in FIG.

In the full screen mode, the aspect ratio is 1.
The 6: 9 landscape image is written in the liquid crystal panel so that the landscape size matches the landscape size of the liquid crystal panel. Therefore, as shown in FIG. The part where the video exists) is written.
A normal image with an aspect ratio of 4: 3 is also written in the liquid crystal panel so that its horizontal size matches the horizontal size of the liquid crystal panel. Therefore, as shown in FIG. The image with the cut off is written on the entire liquid crystal panel P.

As shown in FIG. 4A, when the writing position of the on-screen image 100 on the liquid crystal panel P is set to the optimum position in the full screen mode,
For example, as shown in FIG. 4B, the video and the on-screen image 100 are displayed on the screen S. Figure 4
Then, in the case where the input image is a horizontally long image, the zoom of the optical system is manually adjusted so that the horizontally wide image is displayed in conformity with the horizontally wide width of the screen S having an aspect ratio of 4: 3. An example of the case is shown.

When the display mode is switched to the normal mode while the writing position of the on-screen image on the liquid crystal panel is fixed, that is, the on-screen image 100 is displayed on the liquid crystal panel P as shown in FIG. 5 (a). When written, for example, as shown in FIG. 5B, the video and the on-screen image 100 are displayed on the screen S. FIG. 5 shows an example in which the input image is a normal image and the zoom of the optical system is manually adjusted so that the normal image is displayed on the full screen S of the aspect ratio of 4: 3. Shows. In this case, a part of the on-screen image 100 is projected from the video and also projected from the screen S.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a liquid crystal projector capable of displaying an on-screen image at an optimum position according to a display mode.

[0012]

According to a first aspect of the present invention, there is provided a liquid crystal projector having a plurality of display modes in which image writing sizes to the liquid crystal panel are different, and the display position of the on-screen image is displayed in the display mode. It is characterized in that it is provided with control means for controlling according to.

According to a second aspect of the present invention, in the liquid crystal projector according to the first aspect, the control means controls the on-screen image so that the on-screen image is located inside the display image according to the display mode. It is characterized in that it controls the display position.

The invention described in claim 3 is the invention according to claim 1 or 2.
In the liquid crystal projector described in [1], the plurality of display modes include a display mode suitable for each of a plurality of types of input images having different aspect ratios.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS.

FIG. 6 shows the structure of a liquid crystal projector. The control of the liquid crystal projector is the control related to the power supply,
It can be divided into control related to signal processing.

First, the power supply-related control will be described. AC
The AC voltage input from the outlet 1 is converted into a DC voltage by the active filter 2. The DC voltage obtained by the active filter 2 is sent to the main power supply circuit 3 and also to the lamp power supply circuit 6 via the lamp power supply switch 5.

The main power supply circuit 3 includes a CPU power supply and a CP.
A power supply for circuits other than U is generated. The CPU power generated by the main power circuit 3 is supplied to the CPU 30. The circuit power generated by the main power circuit 3 is supplied to the power terminals of each circuit via the circuit power switch 4.

The lamp power switch 5 and the circuit power switch 4 are on / off controlled by the CPU 30. When the lamp power switch 5 is turned on, a voltage is applied to the lamp (backlight light source lamp) 7, and the lamp 7
Lights up. When the circuit power switch 4 is turned on, power is supplied to each circuit.

Next, control related to signal processing will be described. This liquid crystal projector has a video signal input terminal 11 for inputting an analog RGB signal (computer input signal) from a computer and a video signal input terminal 1 for inputting an AV input signal (composite video signal).
2 and. The RGB signal input to the video signal input terminal 11 is sent to the input changeover switch 15.

The AV input signal input to the video signal input terminal 12 is separated into a luminance signal and a chrominance signal by the Y / C separation circuit 13 and input to the video decoder 14. CPU30
Receives the presence / absence of a signal, a color system, and the like from the video decoder 14, and transmits control data corresponding to the signal to the video decoder 14. The video decoder 14 converts an input signal into an RGB signal and outputs it. Video decoder 1
The RGB signals from 4 are sent to the input changeover switch 15.

The CPU 30 controls the input changeover switch 15 based on the input changeover signal from the operation section 34 to select the computer input or the AV input. The signal selected by the input selector switch 15 is A
It is sent to the / D converter 16.

The VCO 22 generates a sampling frequency according to the input signal based on the control data from the CPU 30 and outputs it to the A / D converter 16. The A / D converter 16 samples the input signal in synchronization with the sampling frequency input from the VCO 22, and outputs the obtained digital signal to the signal processing gate array 17.

The DRAM 18 stores a video signal,
Display other than video signal, so-called on-screen display (O
SD) and so on.

The signal processing gate array 17 temporarily stores the video data input from the A / D converter 16 in the DRAM 18, performs processing such as scanning line conversion, and turns on the obtained video signal when necessary. Combine screen images. The video signal output from the signal processing gate array 17 is sent to the D / A converter 19.

The digital signal input to the D / A converter 19 is converted into an analog signal and input to the color signal driver 20. The color signal driver 20 corrects color signals such as brightness based on the control data received from the CPU 30, and
Converts the DC curve according to the characteristics of the panel. The signal output from the color signal driver 20 is sent to the sample & hold circuit 21 and is sampled for output to the liquid crystal panel.

For liquid crystal panels, there are usually 6 phases, that is, 6 phases.
Batch writing is done in dot units, so sample &
The hold circuit 21 fetches 6 dots of data and collectively outputs the data. From the sample & hold circuit 21, RG
Corresponding data is sent to the respective liquid crystal panels 23, 24, 25 of B.

The timing controller 26 is the CPU 3
Based on the control data received from 0, timing control of the sample & hold 21 and each liquid crystal panel 23, 24, 25 is performed.

The CPU 30 has a ROM 31 for storing the program and the like, a RAM 32 for storing necessary data, and a non-volatile memory 33 for storing a display mode. An operation unit 34 is connected to the CPU 30. The display modes include a full screen mode and a normal mode as described in the related art. The display mode can be switched by the operation unit 3 by the user.
It is performed based on the operation of 4.

FIG. 7 shows a display control processing procedure of the on-screen image by the CPU 30. When a lamp lighting command (input video display command) is input from the operation unit 34 by a user operation (step 1), the lamp 7 is turned on (step 2), and the display mode currently set from the non-volatile memory 33 is changed. It is read into the RAM 32 (step 3).

Then, an image display size (size for writing in the liquid crystal panel) and a display position (writing position in the liquid crystal panel) are set in the signal processing gate array 17 according to the currently set display mode (step 4).

It is determined whether or not an on-screen display command is input from the operation unit 34 by a user operation (step 5). If the on-screen display command has not been input, the process proceeds to step 7.

When an on-screen display command is input, the display position (writing position on the liquid crystal panel) of the on-screen image is determined according to the currently set display mode, and the on-screen is turned on at the determined display position. On-screen image data (OSD data) is transferred to the DRAM 18 so that a screen image is displayed (step 6). Then, the process proceeds to step 7.

When the currently set display mode is the full-screen mode, for example, the on-screen image 100 is written on the liquid crystal panel P as shown in FIG. 4 (a) and shown in FIG. 4 (b). The display position of the on-screen image is determined so that the on-screen image 100 is displayed at the upper left of the image displayed on the screen S. In FIG. 4, when the input image is a horizontally long image, the zoom of the optical system is manually performed so that the horizontally wide image is displayed so as to match the width of the screen S with an aspect ratio of 4: 3. An example of the case of adjustment is shown.

On the other hand, when the currently set display mode is the normal mode, the on-screen image 100 is written on the liquid crystal panel P as shown in FIG. 8 (a) and shown in FIG. 8 (b). The display position of the on-screen image is determined so that the on-screen image 100 is displayed at the upper left of the image displayed on the screen S. FIG. 8 shows an example in which the input image is a normal image, and the zoom of the optical system is manually adjusted so that the normal image is displayed on the full screen S with an aspect ratio of 4: 3. Shows.

In step 7, it is determined whether or not a display mode switching command has been input from the operation unit 34 by a user operation. When the display mode switching command is input, the display mode is changed and the changed display mode is stored in the non-volatile memory 33 (step 8). Then, the process returns to step 4.

If the display mode switching command has not been input, it is determined whether or not a lamp extinguishing command (input video display stop command) has been input from the operation unit 34 by the user operation (step 9), and the lamp extinguishing command is issued. If is not input, the process returns to step 5. When the lamp command is input, after turning off the lamp 7 (step 10),
Return to step 1.

[0038]

According to the present invention, the on-screen image can be displayed at the optimum position according to the display mode.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an example of a normal image having an aspect ratio of 4: 3 and an example of a horizontally long image having an aspect ratio of 16: 9.

FIG. 2 is a schematic diagram for explaining a method of writing an input image to a liquid crystal panel in a normal mode.

FIG. 3 is a schematic diagram for explaining a method of writing an input image to a liquid crystal panel in a full screen mode.

FIG. 4 is a schematic diagram showing a writing position of an on-screen image on a liquid crystal panel and a display position on a screen in a full-screen mode.

FIG. 5 shows a writing position of the on-screen image on the liquid crystal panel when the display mode is switched to the normal mode while the writing position of the on-screen image on the liquid crystal panel is fixed at the writing position in the full-screen mode. It is a schematic diagram which shows the display position on a screen.

FIG. 6 is a block diagram showing a configuration of a liquid crystal projector.

FIG. 7 is a flowchart showing a procedure for display control processing of an on-screen image by the CPU 30.

FIG. 8 is a schematic diagram showing a writing position of an on-screen image on a liquid crystal panel and a display position on a screen in a normal mode according to an embodiment of the present invention.

[Explanation of symbols]

7 Light source lamp for backlight 30 CPU 31 ROM 32 RAM 33 Non-volatile memory

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G09G 3/20 G09G 3/20 650B 5C080 660 660E 5C082 680 680C H04N 5/74 H04N 5/74 K // G09G 5/00 530 G09G 5/00 530M F term (reference) 2H088 EA12 HA06 MA01 2H093 NC01 NC14 NC23 NC24 NC28 NC50 ND01 ND60 NG02 2K103 AA05 AA21 AB10 CA38 CA41 5CBC AAF 01 AF13 AF08 AF11 AF13 AF53 AF34 AF43 AF43 AF43 AF34 AF43 AF34 AF43 AF34 AF43 AF34 AF53 AF BF11 BF13 BF15 BF24 BF28 BF44 EC11 FA05 FA06 FA07 FA08 FA56 5C058 AA06 BA18 BA22 BA35 5C080 AA10 BB05 CC03 DD30 EE01 EE17 EE21 EE22 EE26 EE29 EE30 FF03 FF11 GG02 GG07 GG08 JJ01 JJ02 JJ07 KK43 5C082 AA02 AA39 BA20 BA27 BA36 BB02 BB03 BB15 BC03 BC16 BD02 CA55 CB01 CB05 CB10 DA54 DA55 EA08 MM09

Claims (3)

[Claims] 1. A liquid crystal projector having a plurality of display modes in which video writing sizes to a liquid crystal panel are different, and comprising a control means for controlling a display position of an on-screen image according to the display mode. Characteristic liquid crystal projector. 2. The control means controls the display position of the on-screen image so that the on-screen image is located inside the display image according to the display mode. The described liquid crystal projector. 3. The liquid crystal projector according to claim 1, wherein the plurality of display modes include a display mode suitable for each of a plurality of types of input images having different aspect ratios.