JP2001350197A - Rear projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display vertically long and laterally long images, and character information, etc., while easily switching them in accordance with the display contents without deteriorating the resolution. SOLUTION: A projecting block 5 for enlarging an image displayed on liquid crystal panels 14, 15 and 16 as light valves and projecting the image to a screen 2 is made a unit, and the display device is provided with a projecting block rotating mechanism 7 as a rotating means for rotating the projecting unit around the center axis of a projecting lens 18, and an image display angle changing means for optionally changing the display angle of the light valve image enlarged and projected on the screen 2, and the light valve is irradiated with the light emitted from a light source, and the light is projected from behind the screen 2 through the projecting lens 18 so as to display the enlarged image on the screen 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rear projection display device for displaying images, character information, and the like.

[0002]

2. Description of the Related Art Conventionally, in a rear projection type display device using a light valve such as a liquid crystal panel having a horizontally long aspect ratio such as 4: 3 or 16: 9, a vertically long image, character information, or the like is displayed. In order to switch and display the image, as shown in FIG. 8, a vertically long image is displayed on a part of a liquid crystal panel 70 which is a light valve having a horizontally long display screen, and the image is enlarged and projected to display a display image 71. There is a way to get it.

[0003] Further, in a state where vertically long video and character information are rotated by 90 degrees on a horizontally long light valve, all the pixels of the light valve are used for display, and the display main body is rotated by 90 degrees and installed. There is a method of providing a rotation mechanism on the back surface of the display body, rotating the display body in accordance with display contents, and performing display.

[0004]

However, in the above-mentioned conventional rear projection display device, for example, in a method of displaying a vertically long image or character information on a part of a horizontally long light valve and enlarging and projecting the same, one of the elements is used. Since the portion is enlarged and displayed, there is a problem that unused pixels are present and the resolution is reduced.

Further, in the method of installing the display body by rotating it in advance, or by providing a rotating mechanism on the back of the display to rotate the body to perform display, if the rear projection display device is large, it is not easy to change the installation state. Not
Also, when a rotating mechanism is provided, there is a drawback that the mechanism becomes large, and it is difficult to change the angle of the display according to the display content.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of a first invention of the present application is to provide a large rear projection display device without changing the installation state of a display main body. It is an object of the present invention to provide a technology that makes it possible to easily switch and display a horizontally or vertically long image or character information according to display contents without reducing resolution by using all pixels of a display element. .

A second object of the present invention is to provide a technique capable of displaying the same image quality in the rear projection display device even when switching between a landscape image and a portrait image. is there.

[0008]

In order to achieve the above object, the present invention illuminates light from a light source onto a light valve such as a liquid crystal panel and projects the light from the back surface of a screen by a projection lens. In a rear projection display device that displays an image enlarged on the screen, a rotation unit that rotates a projection unit that enlarges and projects an image displayed on the light valve on a screen with respect to a projection lens center line. Image display angle changing means for arbitrarily changing the display angle of the image of the light valve magnified and projected on the screen.

In a preferred embodiment of the present invention, white light from a light source is transmitted or reflected by a light valve such as a liquid crystal panel on a screen constituted by a Fresnel lens and a lenticular sheet, and an image of the light valve is projected by a projection lens. In a rear projection display device that enlarges and projects on a screen, white light from a light source is reflected or transmitted by a light valve, and a projection block that enlarges and projects an image of the light valve by a projection lens is held by a projection block holding member. A projection block rotating mechanism for rotating the projection block and the projection block holding member with respect to the center of the optical axis of the projection lens, and by rotating the projection block, an image of the light valve projected on the screen at an arbitrary angle It is desirable to be able to rotate.

In the above configuration, a projection block, which is a part of the rear projection type display device, is rotated with respect to a screen to use all pixels of the display element.
It is possible to switch and display an image, character information, or the like at an arbitrary angle according to the display content without lowering the resolution. In addition, by rotating only the projection block, it is not necessary to rotate the entire rear projection display device, and it is possible to easily switch the display angle without changing the installation state.

The Fresnel lens and the lenticular sheet constituting the screen of the rear projection type display device are square, and the lens center of the Fresnel lens is located at the center of the square. The lens enlarges the image displayed on the light valve symmetrically in the vertical and horizontal directions with respect to the center line of the projection lens, and the optical axis center line of light incident on the screen from the projection lens is incident on the center of the screen, and It is preferable that the light is incident perpendicularly to the screen surface.

[0012] In the above configuration, since the screen surface is square, the projected image can be rotated in accordance with the display content and the same projected area can be obtained regardless of whether the image is displayed horizontally or vertically. In addition, the center of the lenticular lens that prevents the brightness from being reduced by bending the light around the periphery of the screen is the center of the square, and the projection lens enlarges the display image of the light valve vertically and horizontally symmetrically with respect to the lens center line, and projects. By making the center of the optical axis of the light incident on the screen from the lens perpendicular to the center of the screen surface and perpendicular to the screen surface, the projection block is rotated, and the image on the screen is rotated to display either horizontally or vertically. In this case, the same image quality can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing the outline of the rear projection type liquid crystal display device of the present embodiment. In FIG.
Reference numeral 1 denotes a main body, and 2 denotes a screen composed of a lenticular sheet 3 and a Fresnel lens 4. The lenticular sheet 3 is for bending horizontal light to widen the horizontal viewing angle, and forms a projection image on this surface. The Fresnel lens 4 bends light at the periphery of the screen to prevent a decrease in brightness at the periphery. The lenticular sheet 3 and the Fresnel lens 4 are both square. The lens center of the Fresnel lens 4 is the center of the square. Numeral 5 is for transmitting light from a light source to a liquid crystal panel serving as a light valve, to enlarge an image displayed on the liquid crystal panels 14, 15, 16 (see FIG. 4 and the like), and to enlarge and project the image on the screen 2 by the projection lens 18. 2 shows a projection block of FIG. Reference numeral 6 denotes a projection block holding member that holds the projection block 5, and 7 denotes a projection block rotation mechanism that constitutes a rotation unit. The projection block 5 and the projection block holding member 6 are unitized, and the unitized projection unit is connected to a projection lens. 1
8 along the optical axis center. 2 is a side view of FIG. 1, and FIG. 3 is a plan view of FIG. FIG. 4 shows a projection block 5, a projection block holding member 6, and a projection block rotation mechanism 7.
FIG. 5 is a plan view schematically showing the arrangement of optical components in the projection block. 2, 3 and 4, the projection block holding member 6 includes a support 30 for fixing the projection block, an axis 31 for rotating the projection block 5 along the optical axis of the projection lens 18, and a predetermined position. Support rod 3 used to rotate the projection block
2, and a screw portion 33 for fixing the projection block 5 at a predetermined position. The support rod 32
As shown in FIG. 3, the protruding portion is provided on the back surface of the support portion 30 and partially protrudes to the back side of the support portion 34 through an arc-shaped long hole 34 a described later. The screw portion 33 is connected to the shaft 31
Are provided as appropriate at a plurality of locations on the concentric circles.

The projection block rotating mechanism 7 includes a support portion 34 fixed to the main body 1, a bearing 35 for supporting the shaft 31,
And a thumb screw 36 for fixing the projection block 5. The thumbscrew 36 is fixed to the projection block holding member 6 at a predetermined angular position by being screwed into the above-described screw portion 33 through a through hole formed in the support portion 34. The support portion 34 is formed with an arc-shaped long hole 34a over an angle range of about 90 degrees along a concentric circle with the bearing 35, and the support rod 32 passing through the arc-shaped long hole 34a is formed in the arc-shaped long hole 34a.
It is movable along. When the projection unit is rotated, the support rod 32 is stopped at an arbitrary position between both ends of the arc-shaped long hole 34a, and a thumb screw 36 is screwed into a corresponding one of the plurality of screw portions 33 and fixed. The display angle of the image displayed on the light valve can be arbitrarily changed.

2 and 3, the projection lens 1
The projection light 41 enlarged and projected by the projection lens 8
Is enlarged symmetrically with respect to the optical axis center 40 of the
At the center of the vertical direction.

In FIG. 5, 8 is a light source, 9 is a dichroic mirror that transmits only the blue component of white light and reflects other components, and 10 is a green component of the light excluding the blue component transmitted by the dichroic mirror 9. A dichroic mirror that reflects only the red component and transmits the remaining red component,
Reference numerals 11, 12, and 13 are total reflection mirrors. Reference numeral 14 denotes a blue liquid crystal panel for displaying an image corresponding to blue, reference numeral 15 denotes a green liquid crystal panel similarly corresponding to green, and reference numeral 16 denotes a red liquid crystal panel similarly corresponding to red.

Reference numeral 17 denotes a dichroic prism that combines the lights separated by the dichroic mirrors 9 and 10 and incident on the respective liquid crystal panels 14, 15 and 16. Reference numeral 18 denotes a projection lens, and 19 denotes a housing for holding components from the light source 8 to the projection lens 18.

As shown in FIG. 4, each of the liquid crystal panels 14, 15, 16 is installed horizontally long, and when the projection block 5 is horizontal with respect to the main body 1 as shown in FIG. As a result, the image enlarged and projected on the screen 2 becomes horizontally long as shown in FIG. In FIG. 6A, reference numeral 50 denotes a liquid crystal panel, and a hatched portion 51 denotes an image projected on the screen 2.

In order to rotate the angle of the image projected on the screen 2 in accordance with the display contents, FIGS.
As shown in FIG. 2, a lid 37 (FIG. 2)
Open), loosen the thumbscrew 36 fixed to the screw portion 33 and fixing the projection block holding member 6, and
, The entire projection block holding member 6 is manually rotated by 90 degrees in the direction of arrow A along the shaft 31 and the bearing 35.

FIG. 7 is a perspective view showing an outline when the projection block 5 and the projection block holding member 6 to which the projection block 5 is fixed are rotated by 90 degrees. After the rotation is completed, the thumb screw 36 is tightened again to fix the position of the projection block holding member 6. As a result, the projection block 5 is rotated by 90 degrees, and the image displayed on the screen 2 is equivalent to using a vertically long liquid crystal panel as shown in FIG. FIG.
In (b), reference numeral 60 denotes a liquid crystal panel, and a hatched portion 61
Indicates an image displayed on the screen 2. In this case, since the screen 2 has a square shape, a vertically long image can be displayed using all the pixels of the liquid crystal panel 60.

[0021]

As described above, according to the first aspect of the present invention,
By rotating only the projection unit constituting the rear projection display device by 90 degrees with respect to the screen,
Without changing the installation state of the display body, using all the pixels of the light valve, without lowering the resolution,
It is possible to arbitrarily switch a horizontally or vertically long image or character information to be displayed horizontally or vertically. By rotating only the projection block, switching can be easily performed as compared with rotating the entire rear projection display device.

According to the second aspect of the present invention, the screen has a square shape, the lens center of the Fresnel lens forming the screen has the square center, and the projection lens has the display image of the light valve as the lens center line. On the other hand, the projection block is rotated by vertically and horizontally symmetrically enlarging, making the optical axis center of the light incident on the screen from the projection lens perpendicular to the screen center, and the screen surface,
Regardless of whether the image on the screen is displayed horizontally or vertically, the same projected area and image quality can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an outline of a rear projection display device according to an embodiment of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is a plan view of FIG. 1;

FIG. 4 is a perspective view showing an outline of a projection block and its unit, a projection block holding member, and a projection block rotating mechanism which constitute the rear projection type display apparatus according to the embodiment of the present invention.

FIG. 5 is a plan view showing an outline of a projection block according to an embodiment of the present invention.

FIG. 6A is a schematic diagram showing a projection image when the projection block according to the embodiment of the present invention is parallel to the main body,
(B) is a schematic diagram showing a projection image when the projection block is perpendicular to the main body.

FIG. 7 is a perspective view schematically showing the rear projection type display device when the projection block and the projection block holding member according to the embodiment of the present invention are perpendicular to the main body.

FIG. 8 is a perspective view schematically showing an example of a conventional rear projection display device.

[Explanation of symbols]

1: body, 2: screen, 3: lenticular sheet,
4: Fresnel lens, 5: projection block (constituting a projection unit), 6: projection block holding member, 7: projection block rotating mechanism (rotating means), 8: light source, 9: blue transmission dichroic mirror, 10: green reflection Dichroic mirror, 11, 12, 13: Total reflection mirror, 14: Blue liquid crystal panel, 15: Green liquid crystal panel, 16: Red liquid crystal panel, 17: Dichroic prism, 18: Projection lens, 19: Housing, 30: Support, 31:
Shaft, 32: support rod, 33: screw part, 34: support part, 34
a: arc-shaped long hole, 35: bearing, 36: thumb screw, 37: lid, 40: center of optical axis of projection lens, 41: projection light, 50:
Liquid crystal panel, 51: display image, 60: liquid crystal panel, 6
1: display image, 70: liquid crystal panel, 71: display image.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 9/31 G02F 1/1335 530 (72) Inventor Shigehiro Kadota 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Hiroto Yasumura 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Minoru Noji 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F term (reference) 2H088 EA15 EA18 EA19 HA13 HA26 HA27 HA28 MA20 2H091 FA05Z FA27Z FA28Z FA41Z FD13 LA11 LA30 5C060 EA01 GA02 GB01 GB09 GD00 HC00 HC07 HC20 HC21 HD05 JB06 5G435 AA01 BB12 BB17 GG05 DD05

Claims (2)

[Claims] 1. A rear projection display for irradiating light from a light source to a light valve such as a liquid crystal panel and projecting the light from a back surface of a screen by a projection lens to display an enlarged image on the screen. In the apparatus, a rotation unit for rotating a projection unit that enlarges and projects an image displayed on the light valve onto a screen with respect to a projection lens center line, and a display angle of the image of the light valve that is enlarged and projected on the screen And an image display angle changing means for arbitrarily changing the angle. 2. The rear projection display device according to claim 1, wherein the screen is formed by a square Fresnel lens and a lenticular sheet, and the optical axis center of the Fresnel lens is located at the center of the screen.
The image displayed on the light valve is magnified symmetrically with respect to the center line of the projection lens by the projection unit that enlarges and projects the image of the light valve onto the screen, and the light incident on the screen from the projection lens. Wherein the optical axis center line is incident on the center of the screen and perpendicular to the screen surface.