JP6083994B2 - Image display device - Google Patents

Description

The present invention relates to an image display device , and more particularly to a projection type image display device having a light control mechanism capable of adjusting the amount of incident light.

  Conventionally, a shutter mechanism that blocks projected light so that the user can stand in front of a projection-type image display device, and a diaphragm for changing contrast, according to usage such as presentation at a conference or watching a movie at home. A projection type image display device equipped with a mechanism and the like is known.

  Patent Document 1 discloses a mechanical variable stop mechanism that changes a light shielding amount by moving a plurality of light shielding plates back and forth in the optical axis direction in order to suppress a decrease in contrast due to unnecessary light.

JP 2002-72361 A

  However, when a light control mechanism such as a shutter mechanism or a diaphragm mechanism is mounted to improve optical performance such as contrast, it is necessary to provide an actuator for operating the light control mechanism, which increases the size of the device. There was a problem.

In order to solve the above problems, an image display device according to the present invention is an image display device including a light modulation element and an illumination system that illuminates the light modulation element with light from a light source , wherein the illumination system includes: In order from the light source side, a first fly-eye lens, a second fly-eye lens, a polarization conversion element, a dimming mechanism that adjusts the amount of light by opening and closing operations of a plurality of light shielding plates, a condenser lens, and a reflection lens The image display device includes an actuator that drives the dimming mechanism, and the light incident side to the reflecting member and the light emitting side from the reflecting member are the front side , At least a part of the actuator is disposed on the back side of the reflecting member ,
It is characterized by that.

  According to the present invention, by effectively using the space formed by disposing the reflecting member in the optical system, it is possible to suppress an increase in the size of the device due to the provision of the light control mechanism.

1 is a schematic plan view of an optical unit of a projection type image display apparatus according to an embodiment of the present invention. The perspective view which looked at the aperture mechanism which concerns on embodiment of this invention from the front The perspective view which looked at the aperture mechanism which concerns on embodiment of this invention from back The front view of the aperture mechanism according to the embodiment of the present invention when fully open and when fully closed

  FIG. 1 is a schematic plan view of an optical unit 2 of a projection type image display apparatus according to an embodiment of the present invention. FIG. 1A is a cross-sectional view parallel to the normal line of the reflecting mirror 8 and the optical axis of the illumination optical system. FIG. 1B is a cross-sectional view of FIG. 1A viewed from the right side of the drawing.

  The light emitted from the light source 1 such as an ultra-high pressure mercury lamp that emits white light includes a first fly-eye lens 3 in which rectangular lenses are arranged in a matrix, and lenses corresponding to individual lenses of the first fly-eye lens. It passes through the second fly-eye lens 4 that it has. Then, the light passes through the polarization conversion element 5 that aligns the unpolarized light with light having a predetermined polarization direction, and enters the light shielding unit 203.

  The light incident on the light shielding unit 203 is adjusted to a desired light amount by the opening / closing operation of the light shielding unit 203. The opening / closing operation of the light shielding unit 203 is driven by the driving force of the actuator 201 (driving unit) transmitted by the link mechanism 202. Hereinafter, a device including the actuator 201, the link mechanism 202, and the light shielding unit 203 is referred to as a light shielding device 6.

  The light that has passed through the light shielding portion 203 is incident on the first condenser lens 7 and then reflected by the reflecting mirror 8 (reflecting member) that bends the incident light substantially at a right angle, so that the optical path is bent. The light reflected by the reflecting mirror 8 passes through the second condenser lens 9.

  Then, it reflects R light (light in the red wavelength region) and B light (light in the blue wavelength band) and enters the dichroic mirror 11 that transmits G light (light in the green wavelength band). The G light transmitted through the dichroic mirror 11 is incident on a G polarization beam splitter 12 that transmits P-polarized light and reflects S-polarized light. The R light and B light reflected by the dichroic mirror 11 are converted into P polarized light while the R light remains S polarized light by a wavelength selective phase difference plate (not shown). The S-polarized R light is reflected by the RB polarization beam splitter 13 and the P-polarized B light is transmitted, whereby the RB light is color-separated.

  The G light reflected by the G polarizing beam splitter 12 enters the G reflective liquid crystal panel 14 (light modulation element), and the R light and B light separated by the RB polarizing beam splitter 13 are R Is incident on the reflective liquid crystal panel 15 for B and the reflective liquid crystal panel 16 for B.

  The light modulated by each reflective liquid crystal panel is guided to a combining element 17 for combining R, G, and B light. The combining element 17 is, for example, a polarization beam splitter, a dichroic mirror, a dichroic prism, or the like.

  The light synthesized by the synthesis element 17 is enlarged and projected by a projection lens 18 onto a projection surface such as a screen (not shown).

  As shown in FIG. 1, when the light incident side and the light emission side of light from the light source with respect to the reflection mirror 8 are the front side, the space formed by the reflection mirror 8 is effectively used, and the actuator is provided on the back side of the reflection mirror 8. By arranging 201, an increase in size of the apparatus can be reduced. In other words, it is possible to reduce the size of the apparatus by arranging the actuator 201 on the side opposite to the light shielding portion 203 with the reflection mirror 8 interposed therebetween. In other words, when the cross section perpendicular to the optical axis of the reflecting mirror 8 is viewed from the light source side, the actuator 201 is arranged so that at least a part of the actuator 201 overlaps the cross section, thereby reducing the size of the apparatus. can do. In other words, when the reflecting surface is a flat surface like the reflecting mirror 8, at least a part of the actuator 201 is arranged in a right triangular prism-shaped space having the reflecting surface as a slope, thereby increasing the size of the device. Can be reduced. More preferably, all the actuators 201 are arranged so as to fit in the space. The light shielding device 6 including the actuator 201 is disposed inside the casing.

  FIG. 2 shows an enlarged perspective view of the light shielding device 6. The light shielding device 6 includes an actuator 201, a link mechanism 202, and light shielding portions 203a and 203b formed on a plane centered on the optical axis.

  The link mechanism 202 includes a worm gear 204, a first gear 205, a second gear 206, an output shaft 207, a rotating member 208, and bridge portions 209a and 209b. Further, the link mechanism 202 includes first pins 210a and 210b, second pins 211a and 211b, sliding members 212a and 212b, a base member 213, and guide grooves 214a and 214b.

  Since the second gear 206 is inserted into the output shaft 207 and a rotating member 208 having long holes provided at both ends is coupled, the rotating member 208 rotates in accordance with the rotation of the second gear 206. To do.

  In FIG. 2, the light shielding plates 203a and 203b constituting the light shielding portion 203 are divided into the two light shielding plates 203a and 203b, and the symbols a and b are also shown for the members related to the respective light shielding plates. Will be described without separating the members a and b.

  The bridge portion 209 has a holding portion of the light shielding portion 203 formed on the same plane as the light shielding portion 203, and a planar portion bent substantially perpendicular to the light traveling direction side with respect to the plane of the light shielding portion 203. A first pin 210 and a second pin 211 are caulked and formed at the end of the part. In other words, the bridge portion 209 has a plane portion formed on a plane including the light shielding plate 203 and a plane portion perpendicular to the plane.

  A sliding member 212 in which a hole and a long hole are formed is provided between the rotating member 208 and the bridge portion 209, and a first pin 210 is passed through the hole of the sliding member 212. Since the second pin 211 is inserted therethrough, the bridge member 209 is positioned by the sliding member 212. The first pin 210 is also inserted into the elongated hole of the rotating member 208. A guide groove 214 in the vertical direction is formed in the base member 213, and a sliding member 212 is inserted into the guide groove 214. The guide groove 214 restricts the sliding direction (moving direction) of the sliding member 212 to be only the vertical direction.

  With the recent increase in brightness of projection-type image display devices, if the projection light is shielded by a light shielding part such as a diaphragm, the amount of heat generated by the light shielding part increases and the actuator (drive part) of the light shielding part is deteriorated. was there.

  On the other hand, the light shielding portion 203 and the actuator 201 of the first embodiment are configured such that the base member 213 formed in parallel to the optical axis A of the illumination optical system before being bent by the reflecting mirror 8, a part of the bridge portion, and the optical axis. It is connected with the other part of the bridge part formed in the direction perpendicular to A. Thereby, since the space | interval from the light-shielding part 203 to the actuator 201 can be taken long, suppressing the enlargement of an apparatus, degradation of the actuator 201 by a heat | fever can be suppressed.

  In addition, since the actuator 201 is arranged on the back side of the reflection mirror 8, light and heat to the actuator 201 are blocked by the reflection mirror 8, so that it can be said that deterioration of the actuator 201 can also be suppressed.

  The actuator 201 is disposed on the optical axis A side with respect to the base member 213 formed along the optical axis A and a part of the bridge portion.

  With the above configuration, the rotational movement of the actuator 201 is transmitted to the rotating member 208 via the first gear 205 and the second gear 206, and is slid by the first pin 210 inserted through the long hole provided in the rotating member 208. The moving member 212 can be freely moved up and down. As a result, since the bridge portion 209 and the light shielding portion 203 positioned by the sliding member 212 can be freely opened and closed, the amount of light shielding can be adjusted by moving the position of the light shielding portion 203 to a specified position. It becomes possible.

  FIG. 3 shows a second perspective view of the light shielding device 6.

  FIG. 4A is a diagram showing a state in which the opening area formed by the light shielding portions 203 a and 203 b is the widest with respect to the effective light beam 300. FIG. 4B is a diagram illustrating a state in which there is no opening region formed by the light shielding portions 203 a and 203 b with respect to the effective light beam 300.

  In the present embodiment, the light shielding unit that adjusts the amount of light by opening and closing the plurality of light shielding plates formed with the notches has been described. However, instead of the light shielding unit, for example, an optical element having a certain transmittance enters and exits the optical path. The form which adjusts a light quantity by setting it as the mechanism to insert / remove may be sufficient. In this case, the actuator serves as means for driving insertion / removal into and out of the optical path of the optical element.

  In the present embodiment, the light shielding unit 203 is disposed on the light source side with respect to the reflection mirror 8. However, the light shielding plate is disposed in the optical path after the optical axis is bent by the reflection mirror 8. May be. In this case as well, an actuator may be disposed on the opposite side of the light shielding portion with the reflection mirror interposed therebetween.

  Further, in this embodiment, a reflective liquid crystal panel is used, but a form using a transmissive liquid crystal panel or a form using DMD may be used. The present invention can be applied if it has the following.

  In the present embodiment, the reflection mirror bends incident light at a substantially right angle, but the present invention is not limited to this. Not only those that bend at a substantially right angle, but also those that have a reflecting member that reflects the light from the light source in a direction different from the incident direction, according to the design of the optical unit, there is a space in which the actuator can be placed. The invention can be applied.

DESCRIPTION OF SYMBOLS 1 Light source 2 Illumination optical system 8 Reflection mirror 201 Actuator 203 Light-shielding plate

Claims (5)

A light modulation element;
An illumination system that illuminates the light modulation element with light from a light source ,
The illumination system includes, in order from the light source side, a first fly-eye lens, a second fly-eye lens, a polarization conversion element, a dimming mechanism that adjusts the amount of light by opening and closing operations of a plurality of light shielding plates, and a condenser A lens and a reflective member;
The image display device includes an actuator that drives the light control mechanism,
When the light incident side to the reflecting member and the light emitting side from the reflecting member are the front side, at least a part of the actuator is disposed on the back side of the reflecting member .
An image display device characterized by that. The dimming mechanism is a dimming mechanism that adjusts the amount of incident light by opening and closing two light shielding plates along a plane perpendicular to the optical axis,
A gear for transmitting the rotational motion of the actuator,
A rotating member that rotates with the rotation of the gear via a shaft coupled to the gear;
A sliding member coupled to the rotating member;
A base member formed with a guide groove for regulating the sliding direction of the sliding member;
The image display device according to claim 1, further comprising a bridge portion that connects the light shielding plate and the sliding member. The image display device according to claim 2, wherein the bridge portion includes a first plane portion formed on a plane including the light shielding plate and a second plane portion perpendicular to the plane. And said actuator and said light control mechanism includes a first member formed parallel to the optical axis, claim 1 characterized in that it is connected by a second member which is vertically formed to the optical axis 4. The image display device according to any one of items 3 . The plurality of light shielding plates are two light shielding plates;
5. The image display according to claim 1, wherein the dimming mechanism is a mechanism that adjusts a light amount by moving in a direction in which the two light shielding plates approach or move away from each other. Equipment .

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