JPH05316457A - Projection image display device - Google Patents

Abstract

PURPOSE:To facilitate adjustment by attaining the movement of the vertical position of an image and the erasing of the part of the image and interlocking the vertical position of the image and the range of erasing the image in a projection image display device using a liquid crystal panel. CONSTITUTION:An vertical image position moving circuit 8 generates a second vertical synchronization signal for moving the vertical position of the image. An image erasing signal generation circuit 9 generates an image erasing signal for erasing the image from an original vertical synchronization signal and the second vertical synchronization signal to erase the image by switching a video signal by a switch circuit 10. The width of the image erasing signal erasing the lower part of the image automatically varies by interlocking with the image vertical position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type image display device for projecting an image displayed on a liquid crystal panel on a screen.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for a large-screen image display device for enjoying powerful images with the enhancement of video equipment such as video tape recorders and video disc players and video software. As a conventional large-screen image display device, a cathode ray tube (Cathode Ray) is used.
There was a projection-type television using a Tube (hereinafter referred to as a CRT), but a CRT is used because the CRT is used for the image display section.
There was a limit to the miniaturization of the device due to the physical restrictions of the above. In order to remove this limitation and reduce the size of the device, a projection type image display device using a liquid crystal panel in the image display unit has been proposed.

FIG. 7 is a conceptual diagram of an optical configuration of an example of a projection type image display device using a liquid crystal panel. Generally, a projection-type image display device using a liquid crystal panel often uses three liquid crystal panels for green, red, and blue to obtain a color image, but in FIG. 7, only one liquid crystal panel is used for simplicity. Not shown. In FIG. 7, a lamp 1 as a light source is lit by a lamp lighting circuit 2, and radiated light from the lamp 1 is collected by a condenser lens 3 and guided to a liquid crystal panel 4. The liquid crystal panel 4 functions as an optical shutter, and the liquid crystal panel drive circuit 5 is responsive to an input video signal.
Is controlled by the pixel unit. The light passing through the liquid crystal panel 4 is projected on the screen 7 by the projection lens 6.

In most conventional video software, the display device is a television, and thus the aspect ratio of the screen is 3: 4 (hereinafter, referred to as standard size) in most cases. In order to record the screen of a movie as it is, not a standard size screen but 9:16 (or 9:15) called Vista size and 9:21 called Sinesco size are increasing.

FIG. 8 (a) is a state diagram showing a state in which image software in which a Vista size image is recorded on a standard size screen is projected and displayed. When such video software is projected and displayed on the screen by the projection type image display device,
Since the aspect ratio of the screen currently used is 3: 4, the image projected on the screen has a portion where the image is not displayed above and below the image area as shown in FIG.

In order to display the image area of Vista-size image software on the entire screen in the conventional projection type image display apparatus having such a configuration, it is conceivable to use a horizontally long screen having an aspect ratio of 9:16. . Particularly in the projection type image display device, since the image on the liquid crystal panel 4 is projected and displayed on the screen 7 using the projection lens 6,
By using a lens having a magnification conversion function such as a zoom lens for the projection lens 6, it is possible to easily change the size of the screen on the screen 7 and display the video area of the video software on the entire screen 7.

FIG. 8B shows a case where a size of the projection screen is changed by a lens and a Vista-size image is displayed on the entire horizontally long screen. In this case, FIG. 8 (a)
The part where the image shown in is not displayed is projected outside the screen.

[0008]

As described above, by using the zoom lens 6 and the horizontally long screen 7, it is possible to enlarge and project a Vista-size or cinema-size image on the entire screen 7 and enjoy a large-screen image. However, with commercially available video software, the position on the screen where the video of Vista size or Cinesco size is recorded on the screen of standard size is different depending on the software, so the video area is projected on the entire screen 7. For this purpose, it is necessary to adjust the installation positions of the projection type image display device and the screen 7 according to the image software.

Further, as shown in FIG. 8 (b), when the image is enlarged on the entire screen 7, the area other than the image area is projected outside the screen, and the periphery of the screen becomes bright and difficult to see. Generally, Japanese subtitles displayed in the outside of the screen are difficult to see if the Japanese subtitles, which are translated words with video software produced in a foreign country and sold in Japan, are attached to the outside of the video area at the bottom of the screen. There was a problem such as becoming.

The present invention has been made in view of the above points, and when the user enlarges the projection screen to display an image, the user can easily adjust the projection of the image area on the entire screen, and It is an object of the present invention to provide a projection display device capable of erasing a portion of a screen projected and displayed on the outside of the display, and adjusting the portion to be erased easily.

[0011]

In order to solve the above-mentioned problems, the present invention provides a projection-type image display device with image display magnification conversion means for changing the size of a projected image on a screen and display on the liquid crystal panel. Image display position moving means for vertically moving the position of the image to be displayed, and image erasing means for erasing a part of the projected image on the screen, and the image displayed on the liquid crystal panel by the image display position moving means. The range of the erased portion of the projection screen erased by the image erasing means is changed as the position of is moved in the vertical direction.

[0012]

According to the present invention, with the above-described structure, when projecting image software such as Vista-size, cinema-size, or cinema-size in a projection type image display device so as to enlarge and display the image area of the image software on the entire horizontally long screen. ,
The user can easily adjust the position of the image area on the screen and the range of the erased portion that erases a part of the projection screen.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A projection type image display apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a projection type image display apparatus according to an embodiment of the present invention. Note that FIG.
The same components as those in the conventional example shown in FIG.

In FIG. 1, 1 is a lamp which is a light source, 2 is a lamp lighting circuit for lighting the lamp 1, 3 is a condenser lens for collecting the emitted light from the lamp 1, 4 is a liquid crystal panel, 5 Is a liquid crystal panel drive circuit for displaying an image on the liquid crystal panel 4, 6 is a projection lens for projecting an image displayed on the liquid crystal panel 4, 7 is a screen for projecting and displaying an image, 8 is the liquid crystal panel 4 An image vertical position moving circuit for moving the vertical position of the image displayed on the screen to change the vertical position of the screen projected on the screen 7, and 9 erases a part of the image displayed on the liquid crystal panel 4. An image erasing signal generating circuit 10 for generating an image erasing signal for the switching is a switch circuit for switching the video signal according to the image erasing signal generated by the image erasing signal generating circuit 9.

In FIG. 1, the liquid crystal panel 4 is shown for simplicity.
Shows only one sheet. The operation of the projection type image display device having the above configuration will be described below.

The projection lens 6 is a zoom lens whose focal length can be changed, and the screen 7 can be changed by changing the focal length.
You can change the size of the image projected on. When projecting a standard size screen with the projection type image display apparatus of the present embodiment, the focal length of the projection lens 6 is adjusted to the longer focal length side to reduce the enlargement ratio, and the vertical direction of the screen projected on the screen 7 is adjusted. The length in the direction is set so as to fit in the length in the vertical direction of the screen 7.

On the other hand, when projecting a Vista-size or cinema-size screen on a horizontally long screen, the projection lens 6
The focal length of is adjusted to the shorter focal length side to increase the enlargement ratio so that the horizontal length of the image area projected on the screen 7 falls within the horizontal length of the screen 7. To do.

However, when projecting a Vista size or Cinesco size screen on a landscape screen with commercially available image software, the position of the image area where the Vista size or Cinesco size image is recorded on the standard size screen is Since it varies depending on the software, when projected on the screen 7, the image area may be projected to the upper side or the lower side of the screen 7. Therefore, it is necessary to adjust so that the image area is projected on the entire screen 7.

The image vertical position moving circuit 8 counts the number of horizontal synchronizing signals of the data number set by the image vertical position setting signal for the vertical synchronizing signal (VD), and compares it with the original vertical synchronizing signal (VD). A second vertical synchronizing signal (VD ') having a shifted phase is generated. Since the liquid crystal panel drive circuit 5 starts displaying an image on the liquid crystal panel 4 in synchronization with the vertical synchronizing signal, the second vertical synchronizing signal (V
When D ′) is input to the liquid crystal panel drive circuit 5 instead of the original vertical synchronizing signal (VD), the image displayed on the liquid crystal panel 4 has an upper side or a lower side as much as the phase of the vertical synchronizing signal is moved. The image will be moved to.

FIG. 2 is a block diagram showing the structure of the image vertical position moving circuit 8 for explaining the operation thereof. Figure 2
21 is a counter circuit for counting the number of horizontal synchronizing signals for moving the phase of the vertical synchronizing signal, and 22 is an image vertical position setting signal for setting the data counted by the counter circuit 21 (the signal generator is not shown). The data latch circuit 23 holds the data of (1) and the waveform shaping circuit 23 adjusts the polarity and width of the output pulse of the counter circuit 21.

The counter circuit 21 reads the count data held in the data latch circuit 22 by the vertical synchronizing signal and counts the horizontal synchronizing signal by a set number.

The waveform shaping circuit 23 waveform-shapes the output pulse of the counter circuit 21 into a pulse matching the polarity and width of the original vertical synchronizing signal and outputs the pulse.

In this way, the image vertical position moving circuit 8
Is a second vertical synchronizing signal (VD ′) whose phase is shifted by the number of horizontal synchronizing signals counted by the counter circuit 21.
Is output, the position of the image displayed on the liquid crystal panel 4 can be easily moved by changing the data counted by the counter circuit 21 according to the image vertical position setting signal.

The image erasing signal generating circuit 9 in FIG. 1 generates an image erasing signal for erasing a portion of the image displayed on the liquid crystal panel 4 other than the video area. FIG. 3 is a block diagram showing the configuration for explaining the operation of the image erase signal generating circuit 9.

In FIG. 3, reference numeral 31 is a first counter circuit for generating a signal for erasing the upper portion of the image displayed on the liquid crystal panel 4, and 32 is the waveform shaping of the output pulse of the first counter circuit 31. Is a first flip-flop circuit, 33 is a second counter circuit for generating a signal for erasing the lower part of the image displayed on the liquid crystal panel 4, and 34 is an output pulse of the second counter circuit 33. A second flip-flop circuit for waveform shaping, 35 is O
An R circuit, 36 is a data latch circuit for holding the data of the image erasing width setting signal (the signal generating portion is not shown) for setting the data counted by the second counter circuit 33. The data counted by the first counter circuit 31 is set to a constant value.

FIGS. 4A and 4B are timing charts for explaining the operation of the image erasing signal generating circuit 9.

FIG. 4A is a timing chart when the image displayed on the liquid crystal panel 4 is moved upward by the image vertical position moving circuit 8.

The first counter circuit 31 starts counting by the second vertical synchronizing signal (VD ') whose phase is moved by the image vertical position moving circuit 8 and counts the number of horizontal synchronizing signals by the set number of data. To count. The first flip-flop circuit 32 is preset by the original vertical synchronizing signal (VD) and reset by the output pulse of the first counter circuit 31.

The second flip-flop circuit 33 reads the data of the image erasing width setting signal held in the data latch circuit 36 by the original vertical synchronizing signal (VD),
Count the number of horizontal sync signals. The second flip-flop circuit 34 is preset by the original vertical synchronizing signal (VD) and reset by the output pulse of the second counter circuit 33, but the output waveform is inverted because the inverted signal output is used.

The OR circuit 35 ORs the outputs of the first flip-flop circuit 32 and the second flip-flop circuit 34 to obtain an image erasing signal.

The image erasing signal generated by the image erasing signal generating circuit 9 is input to the switch circuit 10. The switch circuit 10 switches the video signal input to the liquid crystal panel drive circuit 5 to a signal for displaying an image in black only while the image erasing signal is at the H level. Therefore, as for the image displayed on the liquid crystal panel 4, the image by the video signal is displayed while the image erasing signal is at the L level, and the image is erased by displaying black during the H level. Further, the image erasing control signal invalidates switching of the video signal by the image erasing signal when a standard size image is projected on the screen 7.

Even if the phase of the second vertical synchronizing signal (VD ') with respect to the original vertical synchronizing signal (VD) is changed, from the second vertical synchronizing signal (VD') set by the first counter circuit 31. The period until the fall of the image erasing signal is always constant and does not change. The image displayed on the liquid crystal panel 4 is the second vertical synchronizing signal (V
Since the display is started by D '), even if the vertical position of the image displayed on the liquid crystal panel 4 is moved by the image vertical position moving circuit 8, the display area of the liquid crystal panel 4 always has a constant range from the top in the upper part of the screen. Will be erased.

Since the period set by the second counter circuit 33 is set by the image erasing width setting signal,
The portion of the lower portion of the screen where the image is erased can be changed by changing the data of the image erase width setting signal. In addition, the second counter circuit 33 uses the original vertical synchronization signal (V
Since the counting is started by D), the timing at which the output pulse of the second counter circuit 33 is output is always at the same position with respect to the video signal even if the phase of the second vertical synchronizing signal (VD ') is moved. Is output with. Therefore, the image deletion range at the bottom of the screen is the second vertical synchronizing signal (VD ').
When the vertical position of the image displayed on the liquid crystal panel 4 is moved by moving the phase of, the width becomes narrower or narrower in synchronization with the vertical position of the image.

FIG. 5 is a state diagram showing a state of the image projected on the screen 7 when the vertical position of the image displayed on the liquid crystal panel 4 is moved, and FIG. FIG. 5B is a state diagram when the screen is moved, and FIG. 5B is a state diagram when the screen is moved downward. It should be noted that FIG. 5A shows a state in which a part of the upper side of the screen is erased on the image erasing portion.

As shown in FIGS. 5 (a) and 5 (b), even if the vertical position of the screen is moved, the erase range at the upper part of the screen does not change. In addition, the erasing start position of the erasing portion at the bottom of the screen is always the same position with respect to the image, and the erasing range is widened or narrowed by moving the vertical position of the image.

As described above, in the present embodiment, the vertical position of the image can be varied, and the erased area on the upper side of the screen is fixed with respect to the erased portion of the image, and the erased area on the lower side of the screen is synchronized with the vertical position of the image. The image deletion range at the bottom of the screen is synchronized with the vertical position of the image by matching the deletion start position of the deletion range at the bottom of the screen with the bottom position of the image area. Automatically changes, facilitating adjustment of the screen position when enlarging and projecting a Vista-size or cinema-size image on the screen.

(Second Embodiment) As a second embodiment of the present invention, a second configuration example of the image erasing circuit 9 will be described with reference to FIG. The other components are the same as those in the first embodiment in terms of configuration and function, and detailed description thereof will be omitted.

FIG. 6A is a block diagram showing a second configuration of the image erasing signal generating circuit 9, and FIG. 6B is a timing diagram when the image is moved to the upper side.

In FIG. 6A, 41 is a first counter circuit, 42 is a second counter circuit, 43 is a flip-flop circuit, and 44 is a data latch circuit. Figure 6 (a)
Unlike the first configuration example shown in FIG. 3, the second configuration example shown in FIG. 3 is configured to preset the flip-flop circuit 43 by the output pulse of the first counter circuit 41.

With this configuration, in the first configuration example shown in FIG. 3, the operation of the image erasing circuit 9 becomes abnormal, so that the phase of the output pulse of the first counter circuit 31 is the original vertical. Although it could not be output before the synchronization signal (VD), it is possible with the configuration of FIG. 6A shown in this embodiment.

[0042]

As described above, according to the projection type image display device of the present invention, the screen position for projecting the image area on the entire screen when the user enlarges the projection screen to display the image. Adjustment becomes easy.

Further, since the portion projected on the outside of the screen can be erased, the user does not feel uncomfortable, and when the vertical position of the image projected on the screen is moved, the erasing range at the top of the screen does not change. Instead, the erasure range at the bottom of the screen automatically changes in synchronization with the vertical position of the image, which has an excellent effect that readjustment of the image erasure range is unnecessary.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a projection-type image display device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an image vertical position moving circuit which is a component of the projection type image display device in the embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of an image erasing signal generating circuit which is a constituent element of the projection type image display device in the embodiment of the present invention.

FIG. 4A is a state diagram showing the operation timing of the image erasing signal generating circuit when the projection image is moved to the upper side in the projection type image display apparatus according to the embodiment of the present invention. State diagram showing the operation timing of the image erasing signal generation circuit when the projected image is moved to the lower side

5A is a state diagram showing a state of a projected image when the projected image is moved to an upper side in the projection type image display apparatus according to the embodiment of the present invention. FIG. State diagram showing the appearance of the projected image when moved to

FIG. 6A is a block diagram showing a configuration of an image erasing signal generation circuit which is a component of a projection type image display device in another embodiment of the present invention. (B) Timing chart of the operation of the image erasing signal generation circuit when the projection image of the same apparatus is moved to the upper side

FIG. 7 is a block diagram showing a configuration of a conventional projection-type image display device.

FIG. 8A is a view showing a Vista size image displayed on a standard size screen, and FIG. 8B is a diagram showing a case where a Vista size image is displayed on the entire landscape screen by changing the size of the projection screen by a lens. State diagram

[Explanation of symbols]

 1 Lamp 2 Lamp Lighting Circuit 3 Condenser Lens 4 Liquid Crystal Panel 5 Control Circuit 6 Projection Lens 7 Screen 8 Image Vertical Position Moving Circuit 9 Image Erase Signal Generation Circuit 10 Switch Circuit

Claims (4)

[Claims] 1. An image display device for projecting an image displayed on a liquid crystal panel onto a screen, comprising image display magnification conversion means for changing the size of a projected image on the screen.
An image display position moving means for vertically moving the position of the image displayed on the liquid crystal panel and an image erasing means for erasing a part of the projected image on the screen are provided, and the liquid crystal is moved by the image display position moving means. A projection-type image display device, wherein a range of an erased portion of a projection screen erased by the image erasing means is changed as a position of an image displayed on a panel is moved in a vertical direction. 2. The image erasing means comprises a counter circuit for counting the number of horizontal synchronizing signals of the video signal and a switch circuit for switching the video signal. 2. The projection type image display device according to claim 1, wherein only the range of the erased portion at the bottom of the screen is variable. 3. The projection type image display apparatus according to claim 1, wherein the image display position moving means is composed of a counter circuit for counting the number of horizontal synchronizing signals of the video signal. 4. The projection type image display apparatus according to claim 1, wherein the image display magnification conversion means is a lens capable of varying a focal length.