JP2924181B2 - Projection type image display device - Google Patents

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 apparatus for projecting a television image projected on a liquid crystal or a cathode ray tube using a projection lens.

[0002]

2. Description of the Related Art In recent years, a projection type image display apparatus for enlarging and projecting a television image projected on a liquid crystal or a cathode ray tube using a projection lens has been frequently used.

[0003] The aspect ratio (screen aspect ratio) of a conventional color television image of the NTSC system or the like is 3: 4, but the aspect ratio is 9:16 for cinema-size software or high-vision broadcasting.

[0004] Therefore, 3 to 4 which is now mainstream in the market
When a cinema-size or high-definition soft image is viewed on a display device having an aspect ratio of?, A black portion appears at the top and bottom of the screen, or the left and right image portions are reproduced in a state where they are cut off.

[0005]

To reproduce the cinema-size or high-definition software on a display having an aspect ratio of 3: 4, which is currently mainstream in the market, as described above, black portions are formed at the top and bottom of the screen. Appears or the left and right parts of the screen are shifted. Also, 9
When software having an aspect ratio of 3: 4 is reproduced on a display having an aspect ratio of 16, black portions appear on the left and right sides of the screen.

When these are enlarged and projected using a projection type image display device, image projection means using a liquid crystal or a cathode ray tube for projection is more required due to restrictions on the size of the entire device and higher resolution of the projected image. At present, high resolution is required. Furthermore, when projecting software having different aspect ratios as described above, the screen in the vertical or horizontal direction is cut off, and the resolution is reduced because the entire area of the display unit of the image projecting means such as a liquid crystal cannot be used. There was a problem that.

An object of the present invention is to solve the above-mentioned problem, and an object of the present invention is to provide a projection-type image display device in which resolution is not deteriorated as much as possible even when software having different aspect ratios is projected.

[0008]

In order to achieve the above object, the present invention enlarges an image projected by a liquid crystal or the like and an image projected by the image projected means on a projection screen by using a projection lens. Means for projecting, a plane mirror provided between the projection lens and image projecting means such as liquid crystal, a driving circuit for driving the image projecting means such as liquid crystal, and an aspect ratio of an input video signal to the image projecting means. And a signal processing circuit for converting the image into an aspect ratio of the projection means. A plurality of projection lenses are provided for one of the image projection means, and at least one of the optical systems has an anamorphic lens (aspect ratio of 3). : A lens for optically enlarging an image of 4: 4 to an aspect ratio of 9:16, or a lens having the opposite effect), and switching the center optical axis using the plane mirror. In which a projection type image display device is configured to allow.

[0009]

According to the present invention, when the aspect ratio of the display portion of the image projecting means such as a liquid crystal is 3: 4, and the image signal having the aspect ratio of 9:16 is inputted, the aspect ratio is increased. Is compressed in the horizontal direction of the image by a signal processing circuit for converting the aspect ratio to an aspect ratio of 3 to 4, and displayed on the display unit of the image projecting means. In this case, the image is returned to the original aspect ratio of 9:16 by operating the plane mirror provided between the plurality of projection lenses and the image projecting means and guiding the image to the projection lens having the anamorphic lens. It is. In this case, by using the entire area of the display unit of the image projecting unit, a projected image can be obtained without lowering the resolution inherent in the display unit of the image projecting unit. When a video signal having an aspect ratio of 3: 4 is input, the video signal is displayed as it is on the display unit of the image projection means, and is projected by the other projection lens having no anamorphic lens by operating the plane mirror. Needless to say.

When the aspect ratio of the display unit of the image projecting means is 9:16, and when the signal having the aspect ratio of 3: 4 is inputted, a signal processing circuit capable of converting the aspect ratio converts the image in the horizontal direction. To increase the aspect ratio to 9: 1
6 to be displayed on the display unit of the image projecting means. At this time, the projected image is guided to a projection lens provided with an anamorphic lens by operating a plane mirror provided between a plurality of projection lenses and image projection means, so that the projected image has an original aspect ratio of 3: 4. Will be returned. When a signal having an aspect ratio of 9:16 is input, it is displayed on the display unit of the image projecting means as it is, and it is needless to say that the plane mirror is operated and projected by a projection lens having no anamorphic lens.

[0011]

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

FIG. 1 is a sectional view of a main part showing the structure of a one-piece projection type image display device using a liquid crystal panel as an image projection means.

First, a case where an input video signal has an aspect ratio of 3: 4 will be described. As shown in the drawing, the light source 1 is driven by a power supply driving circuit 3 with power supplied from a power supply circuit 2 to emit light. The light emitted from the light source 1 is reflected by the reflector 4 and sent to the ultraviolet and infrared cut mirror 5. Only the visible light component of the light incident on the ultraviolet and infrared cut mirrors 5 is incident on a polarizing plate 7 attached to a flat glass plate. Only light of a certain polarization component is incident on the liquid crystal panel unit 8 by the polarizing plate 7.

The liquid crystal panel unit 8 is provided with a liquid crystal panel 9 as an image projecting means having an image display section having an aspect ratio of 3: 4 on an optical axis 10a. Although not shown, the liquid crystal panel unit 8 has a built-in liquid crystal drive circuit.

The liquid crystal driving circuit is connected to a signal processing circuit 11, and the signal processing circuit 11 is connected to the power supply circuit 2.
And an input terminal 12 for receiving a video signal from the outside while being supplied with power.

The light transmitted through the liquid crystal panel 9 has an optical axis 10.
a, and enters the projection lens 13a. Here, the image projected on the liquid crystal panel 9 is enlarged and projected by the projection lens 13a so as to have a required size. The focus is adjusted so that the projection image is formed at a required distance. The projection image enlarged and projected by the projection lens 13a is reflected by the plane mirror 14, and enlarges and projects the image on the liquid crystal panel 9 on a transmission screen 15 having an aspect ratio of 9:16. At this time, the projected image to be formed has an aspect ratio of 3: 4, so that the image is projected on the transmissive screen 15 fully in the up-down direction, but the both ends are shifted in the left-right direction.

Next, a case where the input video signal has an aspect ratio of 9 to 16 will be described. FIG. 2 is a cross-sectional view of a main part showing a configuration when an input video signal has an aspect ratio of 9:16.

In this case, unlike FIG. 1, the liquid crystal panel unit 8 is provided with a liquid crystal panel 9 having an aspect ratio of 3: 4.
However, since the input video signal has an aspect ratio of 9:16, the input video signal is converted by the signal processing circuit 11 into a signal compressed in the horizontal direction so as to match the aspect ratio of the liquid crystal panel 9 of 3: 4. The image is reproduced on the display surface of the liquid crystal so that the image is not displaced.

The light transmitted through the liquid crystal panel 9 is rotatably supported by a fulcrum shaft 17 fixed to a housing not shown in the figure, and is provided with a switching plane mirror 18 provided so as to block the optical axis 10b. Then, the light passes through the optical axis 10c and is incident on the projection lens 13b provided with the anamorphic lens 20 that can enlarge only the lateral direction of the screen on the emission side by the plane mirror 19. Here, the image having the aspect ratio of 3 bodies 4 on the liquid crystal panel 9 is converted to the aspect ratio of the original input video signal of 9: 1.
6, the image is enlarged and projected in the horizontal direction as compared with the vertical direction so that the projection image has a required size. The focus is adjusted so that the projection image is formed at a required distance. The projection image enlarged and projected by the projection lens 13b is reflected by the plane mirror 14, and
The image on the liquid crystal panel 9 is enlarged and projected on a transmission screen 15 having an aspect ratio of 16 pairs. The projected image formed at this time is an image having an aspect ratio of 9:16, so that the image is projected to fill the transmissive screen 15.

According to the present embodiment, regardless of the aspect ratio of the input video signal, the entire area of the display portion of the liquid crystal panel is always used, so that the resolution does not greatly deteriorate for the input video signal having either aspect ratio. A beautiful image can be projected.

In this embodiment, a liquid crystal panel is exemplified as the image projecting means, but the present invention is not limited to this. When the display unit of the image projection means is 9:16 instead of 3: 4 as in this embodiment, the aspect ratio of the input video signal is 9
When the aspect ratio of the input video signal is 3 to 4, the image is displayed on the image display unit of the image projecting means in an enlarged manner by the signal processing circuit.
Thereafter, the projection lens provided with the anamorphic lens is projected in a reduced size in the horizontal direction as compared with the vertical direction, whereby a beautiful image can be provided while suppressing the deterioration of the resolution as in the present embodiment. In this embodiment, the integrated projection type image display device is exemplified, but it goes without saying that the present invention can be used in a two-body type.

[0022]

As described above, according to the present invention, an image projecting means, a projection lens provided so as to project an image of the image projecting means, the projection lens and the image projecting means are provided. A flat mirror provided between, a driving circuit for driving the image projection means, and a signal processing circuit for converting the aspect ratio of the input video signal to the aspect ratio of the display unit having the image projection means, A plurality of the projection lenses are provided for one image projection means, and at least one of the optical systems is provided with an anamorphic lens, and is arranged so that the central optical axis can be switched by the plane mirror. Therefore, even when input video signals with different aspect ratios are added, the solution can be obtained by always using the entire area of the image display section regardless of the aspect ratio of the image projection means. It has been made to be able to provide a less beautiful images every degradation.

Further, in order to change the enlargement ratio at the time of projection, there is also an effect that the mechanism of the switching section can be simplified because the optical path is changed by the switching plane mirror.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a projection type image display apparatus according to the present invention when an aspect ratio of an input video signal is 3: 4.

FIG. 2 is a sectional view of a main part of an embodiment of a projection type image display device when an aspect ratio of an input video signal is 9:16.

[Explanation of symbols]

Reference Signs List 8 liquid crystal panel unit 9 liquid crystal panel with aspect ratio of 3 to 4 11 signal processing circuit 13a projection lens 13a having the same magnification in the vertical and horizontal directions 13b projection lens when magnification in the horizontal direction is larger than the vertical direction 14 plane mirror 15 9:16 aspect Transmission screen with ratio 18 Switching mirror 19 Reflection mirror 20 Anamorphic lens

Claims (1)

(57) [Claims] 1. An image display device, a projection lens provided to project an image of the image display device, a plane mirror provided between the projection lens and the image display device, and a drive for driving the image display device A signal processing circuit for converting an aspect ratio of an input signal into an aspect ratio of a display unit of an image display device, a power supply circuit for supplying the required power, and a housing for supporting these components. A plurality of lenses are provided for one image display device, and at least one of the optical systems includes an anamorphic lens, and the optical axis thereof can be switched by rotating the plane mirror. A projection-type image display device, which is provided.