JP2002365588A - Projection type display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of high luminance and a high contrast ratio being unable to be made compatible with each other, in a projection type display device where a mirror array element is used as a light valve. SOLUTION: The aperture shape of luminous flux illuminating the mirror array element 19 is changed by a variable diaphragm mechanism 16, consisting of a drive mechanism 15 installed in an illumination optical path for illuminating the mirror array element 19 and driven to be turned to an optional angle and a prism block 14 having an air gap 11 in between, and the luminance is applicably prioritized or the contrast ratio is prioritized according to inputted information or selection by a user.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type display device which irradiates an image modulated into a video signal on a light valve with illumination light and enlarges and projects the image on a screen by a projection lens.

[0002]

2. Description of the Related Art Conventionally, a projection type display apparatus which irradiates an image modulated into a video signal on a light valve with illumination light and enlarges and projects the image on a screen by a projection lens is aimed at high luminance and high contrast ratio. An apparatus described in Japanese Patent Application Publication No. 9-500738 is known as an apparatus.

FIG. 9 shows an example of an asymmetrical opening which enables high brightness without deteriorating the contrast ratio in the above-mentioned conventional projection display device. In FIG. 9, the mirror array element 119 has minute mirrors 117 for the number of pixels, and the minute mirror 117 can be arbitrarily rotated at a predetermined angle with respect to a rotation shaft 118. The illumination light for illuminating the mirror array element 119 has an asymmetric aperture shape shown by an aperture shape 123. As a specific implementation method, a method of installing a stop of a predetermined shape in an optical path of an illumination optical system that irradiates light to a mirror array, a method of using a distorted image lens as a constituent lens, and the like are disclosed.

[0004]

However, according to the above-mentioned conventional method, a scene in which priority is given to the luminance such as when projecting an image from a computer in a bright room or a scene in which a contrast ratio is desired to be prioritized such as a movie. The same luminance and contrast ratio result, and it is difficult to obtain a satisfactory image in all cases.

The present invention solves the above-mentioned problem, and can selectively control a case where priority is given to the luminance for transmitting the illumination light as it is and a case where a part of the illumination light is blocked and the contrast ratio is increased according to the input information. An object of the present invention is to provide a projection display device.

[0006]

In order to solve this problem, a projection display device according to the present invention comprises a plurality of micromirrors, and each of the micromirrors is independently provided with a first micromirror in accordance with input information. Angle or a second angle,
A mirror array element in which the rotation axes of the respective micromirrors are all in the same direction; a light source for irradiating the mirror array element with light; and a plurality of light sources for efficiently irradiating the light beam emitted from the light source to the mirror array. Illumination optical means comprising optical elements of
A mirror lens having an angle of 1 is incident thereon, and a projection lens that projects only the incident light, and is disposed at a position where a light beam is transmitted in the illumination optical unit, and has an air gap, and the air gap The angle is rotated in the same direction as the rotation direction of the micro mirror of the mirror array before and after the critical angle with respect to the direction of the light beam at the installation position, and whether the transmitted light beam is totally reflected or transmitted by the air gap is selected. A prism capable of controlling the rotation angle of the prism according to the input information.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(Embodiment 1) FIG. 1 shows an overall configuration diagram of a projection display apparatus according to a first embodiment of the present invention, in which a lamp 1 as a light source and an elliptical mirror for condensing the light are shown. 2
And a color wheel 7 composed of an R filter 3, a G filter 4, and a B filter 5 selectively transmitting red, green, and blue light shown in FIG.
A condenser lens 8 for collimating light emitted from the color wheel 7 at a predetermined divergence angle, and a first lens array 9 and a second lens array 10 for uniformly illuminating an area to be illuminated. Illumination optics,
A prism block 14 including two prisms 12 and 13 which are located in the middle of and in the illumination optical system so as to block a part of a light beam passing therethrough, and constitute an air gap 11 therebetween; A variable aperture mechanism 16 composed of a drive mechanism 15 composed of a motor and gears for rotating the lens and a light valve that receives light from the illumination optical system and acts as a light valve as shown in FIG. A mirror array element 19 in which a large number of micromirrors 17 and rotating shafts 18 are regularly arranged;
, And a projection lens 20 that projects an image of the mirror array element 19.

The operation of the projection display device having the above-described configuration will be described below. As an optical basic operation, white light from a lamp 1 as a light source is
The light is condensed to form a spot and irradiates the color wheel 7. The color wheel 7 includes an R filter 3, a G filter 4, and a B filter 5 that selectively transmit red, green, and blue light, and Since the light is rotationally driven by the drive motor 6, the light transmitted through the color wheel 7 is sequentially switched between red, green, and blue light to form a light beam having a predetermined angle of spread. This light flux is converted into parallel light by the action of the condenser lens 8, and is uniformly illuminated by the action of the first lens array 9 and the second lens array 10 on the surface of the mirror array element 19 which is an illumination area. The micro mirrors of the mirror array element 19 emit light of predetermined pixels by rotating individual micro mirrors according to input information which is image information to be projected and according to the color of light to be irradiated. Reflected to the 20 side,
Can project images. Next, the operation of the variable aperture mechanism 16 arranged in the middle of the illumination optical system will be described. The prism block 14 is made up of two prisms 12 and 13 made of glass material BK7, and an air gap 11 is formed between them. ,
This prism block 14 is driven by a driving mechanism 15 as shown in FIG.
4B, the angle between the transmitted light 21 and the perpendicular of the air gap 11 at that time is 41.16.
° -α and 41.16 ° + α. This 41.16 ° is the critical angle of the glass material BK7. As shown in FIG. 4A, even if the transmitted light 21 in the glass material of the prism 12 is incident on the interface with air at an angle smaller than the critical angle, the predetermined angle is determined. Is refracted through the air gap 11 and then passes through the prism 13 again. At this time, the gap width of the air gap 11 can be set very small, and the light passing through this prism block is transmitted almost linearly. it can. As shown in FIG. 4B, when the transmitted light 21 in the glass material of the prism 12 enters the interface with air at an angle greater than the critical angle, the light is totally reflected at the interface and goes out of the optical path in the direction indicated by the reflected light 22. Irradiated to

FIG. 5A shows an aperture shape 23 of illumination light for illuminating the mirror array element 19 in the state shown in FIG. 4A, and FIG. 5B shows the mirror in the state shown in FIG. FIG. 5 shows an aperture shape 24 of illumination light for illuminating the array element 19.
In (b), a part of the illuminating light beam is blocked by the action of the variable aperture mechanism 16, and the aperture shape 24 is the rotation axis 1 of the micro mirror 17.
An opening shape is obtained by partially cutting out a circle having a linear portion parallel to 8. It is possible to cope with a case where the luminance is prioritized using the change in the opening shape and a case where the contrast ratio is increased. By the way, the luminance can be increased in the case of the opening shape 23, and the contrast ratio can be increased in the case of the opening shape 24. it can.

[0011] Both of these aperture shapes are automatically changed by input information from a computer that requires brightness such as a presentation image from a computer, or an image such as a movie that gives priority to contrast. It becomes possible to select it as you like.

(Embodiment 2) FIG. 6 shows an overall configuration diagram of a projection display apparatus according to a second embodiment of the present invention, in which a lamp 1 as a light source and an elliptical mirror 2 for condensing the light are shown. When,
A color wheel 7 composed of an R filter 3, a G filter 4, and a B filter 5 selectively transmitting red, green, and blue light shown in FIG. A condenser lens 8 for collimating light emitted at a spread angle of the first lens array 9 and a second lens array 9 for uniformly illuminating an area to be illuminated.
An illumination optical system composed of a lens array 10 and an air gap 61 located in the middle of the illumination optical system and so as to block a part of a light beam passing therethrough and having a predetermined curvature therebetween.
, A prism block 64 composed of two prisms 62 and 63, and a variable diaphragm mechanism 66 composed of a driving mechanism 65 composed of a motor and gears for rotating the prism block 64, and illumination. The light from the optical system acts as a light valve, and serves as a light valve. A mirror array element 19 in which a number of micromirrors 17 corresponding to the pixels and their rotating shafts 18 are regularly arranged, as shown in FIG. And a projection lens 20 for projecting an image of the mirror array element 19.

The operation of the projection type display device having the above configuration will be described below. As an optical basic operation, white light from a lamp 1 as a light source is
The light is condensed to form a spot and irradiates the color wheel 7. The color wheel 7 includes an R filter 3, a G filter 4, and a B filter 5 that selectively transmit red, green, and blue light, and Since the light is rotationally driven by the drive motor 6, the light transmitted through the color wheel 7 is sequentially switched between red, green, and blue light to form a light beam having a predetermined angle of spread. This light flux is converted into parallel light by the action of the condenser lens 8, and is uniformly illuminated by the action of the first lens array 9 and the second lens array 10 on the surface of the mirror array element 19 which is an illumination area. The micro mirrors of the mirror array element 19 emit light of predetermined pixels by rotating individual micro mirrors according to input information which is image information to be projected and according to the color of light to be irradiated. Reflected to the 20 side,
Can project images. Next, the operation of the variable stop mechanism 66 arranged in the middle of the illumination optical system will be described. The prism block 64 is made of prisms 62 and 63 made of two glass materials BK7, each having an R side. An air gap 61 having a curvature is formed. The prism block 64 can be rotated by the driving mechanism 65 to the angles shown in FIGS. 7A and 7B, and transmits the transmitted light 71 at that time. The angle between the air gap 61 and the perpendicular at the position is
It is rotated from a state of forming 41.16 ° -α at all positions to a position of forming 41.16 ° + α at all positions. This 41.16 ° is the critical angle of the glass material BK7,
As shown in FIG. 7A, the transmitted light 7 in the glass material of the prism 62
Even if 1 enters the interface with air at an angle less than the critical angle,
The light is refracted at a predetermined angle, passes through the air gap 61, and passes through the prism 63 again. At this time, the gap width of the air gap 61 can be set very small, and the light passing through the prism block 64 is almost linear. Can be transmitted through.
Also, as shown in FIG. 7B, when the transmitted light 71 in the glass material of the prism 62 is incident on the interface with air at an angle equal to or greater than the critical angle, it is totally reflected at the interface and out of the optical path in the direction indicated by the reflected light 72. Irradiated to

FIG. 8A shows an opening 73 of illumination light for illuminating the mirror array element 19 in the state shown in FIG. 7A, and FIG. 8B shows the mirror in the state shown in FIG. 7B. The aperture shape 74 of the illumination light for illuminating the array element 19 is shown. FIG.
In (b), a part of the illuminating light beam is blocked by the action of the variable stop mechanism 66, and the opening shape 74 is the rotation axis 1 of the micro mirror 17.
An opening shape is obtained by partially cutting out a circle having a linear portion parallel to 8. By providing the air gap 61 with a predetermined curvature and controlling the angle of the prism block 64 by the driving mechanism 65, it is possible to continuously change from the opening shape 73 to the opening shape 74.

Thus, the opening shape can be selectively changed according to the input information or the user's preference, and can be continuously changed from emphasis on luminance to emphasis on contrast ratio.

In the above description, a method using one mirror array element has been described. However, the present invention can be similarly applied to a method using a plurality of mirror array elements.

[0017]

As described above, according to the present invention, it is possible to greatly change the opening shape with a small number of component movements, and to emphasize input information and luminance and contrast ratio according to the opening shape. The remarkable effect that the image quality can be changed quickly is obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a projection display apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a color wheel unit.

FIG. 3 is a diagram showing a structure of a mirror array element.

FIG. 4 is a diagram showing an operation of a variable aperture mechanism.

FIG. 5 is a diagram showing an aperture shape of illumination light corresponding to the operation of the variable aperture mechanism.

FIG. 6 is a configuration diagram of a projection display device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing the operation of a variable aperture mechanism.

FIG. 8 is a diagram showing an aperture shape of illumination light corresponding to the operation of the variable aperture mechanism.

FIG. 9 is a diagram showing a fixed aperture shape for a mirror array element according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp 2 Ellipsoidal mirror 3 R filter 4 G filter 5 B filter 6 Drive motor 7 Color wheel 8 Condenser lens 9 1st lens array 10 2nd lens array 11 Air gap 12, 13 Prism 14 Prism block 15 Driving mechanism 16 Variable aperture Mechanism 17 Micromirror 18 Rotation axis 19 Mirror array element 20 Projection lens

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 21/28 G03B 21/28 H04N 5/74 H04N 5/74 B

Claims (4)

[Claims] A plurality of micromirrors, each of which can be independently rotated at a first angle or a second angle in accordance with input information; A mirror array element having the same direction, a light source for irradiating the mirror array element with light, an illumination optical unit including a plurality of optical elements for efficiently irradiating the mirror array with a light beam emitted from the light source; A projection lens that receives light from a mirror forming a first angle among the micromirrors of the mirror array and projects only the incident light, and is disposed at a position where a light beam passes through the illumination optical unit;
The air gap has an air gap, and the angle of the air gap is turned around the critical angle with respect to the direction of the light beam at the installation position, in the same direction as the turning direction of the micro mirror of the mirror array, and the transmitted light beam is air. A projection display device comprising: a prism capable of selecting either total reflection or transmission by a gap; and a driving unit capable of controlling a rotation angle of the prism in accordance with the input information. 2. The projection display device according to claim 1, wherein an air gap of the prism is provided in a part of a transmitted light beam. 3. A micromirror comprising: a plurality of micromirrors; each micromirror being independently rotatable to a first angle or a second angle in accordance with input information; A mirror array element having the same direction, a light source for irradiating the mirror array element with light, an illumination optical unit including a plurality of optical elements for efficiently irradiating the mirror array with a light beam emitted from the light source, and the mirror. A projection lens that receives light of a mirror that forms a first angle among the micromirrors of the array and projects only the light that is incident thereon, and is disposed at a position where a light beam passes through the illumination optical unit,
And, having an air gap composed of surfaces having an arbitrary curvature, the rotation direction of the micro mirror of the mirror array so that the angle of the air gap sequentially exceeds the critical angle with respect to the direction of the light beam at the installation position A prism that rotates in the same direction and selects whether the transmitted light beam is totally reflected or transmitted by an air gap, and a driving unit that can control the rotation angle of the prism according to the input information. A projection display device characterized by the above-mentioned. 4. The prism according to claim 3, wherein the air gap of the prism is provided at a part of the transmitted light beam, and is rotated so that the light beam is totally reflected sequentially from a peripheral portion of the light beam. The projection type display device according to the above.