JPH05303031A - Liquid crystal projector - Google Patents

Abstract

PURPOSE:To fix a mirror used for the liquid crystal projector with high accuracy by a simple structure. CONSTITUTION:In the liquid crystal projector for dividing an illuminating light into plural color components by a spectral mirror, radiating these respective color components to the respective different liquid crystal panels and allowing them to transmit through, synthesizing the light which transmits through the respective liquid crystal panels as a light beam of one system by a synthesizing mirror, and projecting the synthesized light beam to a screen, at least one of the spectral mirror 1 and the synthesizing mirror is stuck and fixed by an ultraviolet hardening resin compound adhesive agent 6 in a state that it is allowed to abut on the prescribed reference surface 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector that projects an image on a screen using a liquid crystal panel.

[0002]

2. Description of the Related Art Conventionally, as a projection type color image display device, a so-called liquid crystal projector using a liquid crystal panel has been developed. In this liquid crystal projector, light from a light source such as a xenon lamp is converted into parallel rays by an optical member, and then separated into three colors of red light, green light, and blue light by a dichroic mirror, and separated into respective optical paths. Place the LCD panel. Then, a red image, a green image and a blue image of the projected image are formed on the liquid crystal panel of each optical path, and the light rays of each optical path are converted into red image light,
After forming the green image light and the blue image light, the respective image lights are combined by a dichroic mirror, and the combined light is enlarged and projected on a screen through a projection lens.

Here, FIG. 4 shows an example of a concrete configuration of a liquid crystal projector. In the figure, reference numeral 10 denotes the entire liquid crystal projector, and this projector 10 reflects light from a light source 11 such as a metal halide lamp to a reflecting mirror 12. To form parallel rays, and the parallel rays are incident on the first dichroic mirror 13 as illumination light. Then, the first dichroic mirror 13 causes the green component from the light from the light source 11 to go straight, and causes the other color components to bend 90 °. And
The bent color component is made incident on the second dichroic mirror 14. In the second dichroic mirror 14, the red component is 90 ° from the color component from which the green component has been removed.
Bend it and let the remaining blue component go straight.

Then, the first dichroic mirror 13
The green component separated by is bent by 90 ° by the mirror 17, and then is transmitted through the green liquid crystal panel 19G on which the green component of the color image to be projected is displayed, and the green image light formed by the transmission is converted into the third image light. It is incident on the dichroic mirror 15. Further, the red component separated by the second dichroic mirror 14 is transmitted through the red liquid crystal panel 19G displaying the red component of the color image to be projected, and the red image light formed by the transmission is transmitted to the third dichroic mirror. 1
5. Then, the third dichroic mirror 15 combines the light transmitted through the red liquid crystal panel 19G and the light transmitted through the green liquid crystal panel 19G, and causes the combined light to enter the fourth dichroic mirror 16. Further, the blue component separated by the second dichroic mirror 14 is transmitted through the blue liquid crystal panel 19B where the blue component of the color image to be projected is displayed, and the blue image light formed by the transmission is reflected by the mirror 18 at 90 °. After bending, the 4th
It is incident on the dichroic mirror 16. Then, in the fourth dichroic mirror 16, the combined light of the red component and the green component from the third dichroic mirror 15,
The blue component light transmitted through the blue liquid crystal panel 19B is combined with the projection lens 20 to produce color image light in which the three primary colors are combined.
Incident on.

Then, the image light output from the projection lens 20 reaches a screen (not shown) to display a color image on the screen.

[0006] With such a configuration, the conventional CRT
Unlike a projector that uses a light source such as an image display unit that also serves as a light source, the liquid crystal panel that is the image display unit and the light source are separate units, so a high-luminance image that corresponds to the brightness of the light source And the resolution is determined by the liquid crystal panel, so that it is possible to project an image with high brightness and high resolution.

[0007]

By the way, in such a liquid crystal projector, unless the optical components such as the dichroic mirror are accurately arranged, the color components of the three colors are not properly synthesized, and the final synthesis is performed. There is a problem in that a color shift occurs in the captured image and the resolution of the projected image deteriorates.

FIG. 5 and FIG. 6 show how the conventional dichroic mirror of this type of liquid crystal projector is attached to the device. FIG. 5 is a front view of the fixing portion of the dichroic mirror. Is a cross-sectional view, for example, the first
The dichroic mirror 13 is fixed to a mount 31 having an opening 32, and the left and right ends of the dichroic mirror 13 are fixed by the mount 31. That is, a mirror fixing protrusion 33 is provided at a predetermined position of the mounting base 31 corresponding to the left and right ends of the dichroic mirror 13, and the protrusion 33 and the left and right ends of the dichroic mirror 13 are double-sided bonded. It is fixed by the tape 34. Further, a mirror fall prevention plate 35 is provided with screws 36 at the left and right ends of the mirror back surface opposite to the bonding surface.
It is fixed by.

Although each mirror in a conventional liquid crystal projector is fixed by using the mounting base having such a structure, fixing with a double-sided adhesive tape is not reliable for long-term storage, and work at the time of fixing is performed. However, the accuracy of mounting the mirror may be deteriorated due to fluctuations in the thickness of the tape due to adhesion of dust or overlapping of the tape itself. Therefore, there has been a demand for the development of a structure that can be mounted with higher accuracy in a liquid crystal projector in which it is necessary to accurately fix a mirror and the like.

In view of the above point, the present invention has an object to enable a mirror used in a liquid crystal projector to be accurately fixed with a simple structure.

[0011]

According to the present invention, illumination light is divided into a plurality of color components by a spectroscopic mirror, and the respective color components are applied to different liquid crystal panels to be transmitted,
In a liquid crystal projector in which light that has passed through each liquid crystal panel is converted into one system of rays by a combining mirror, and the combined rays are projected on a screen, at least one of a spectroscopic mirror and a combining mirror is, for example, as shown in FIG. As shown in FIG. 3, the ultraviolet curable resin adhesive 6 is used to adhere and fix it in a state of being in contact with the predetermined reference surface 3.

[0012]

By doing so, the fixing accuracy of the mirror is secured by the reference surface 3, and the mirror is securely fixed by the ultraviolet curable resin adhesive 6.

[0013]

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

This embodiment is applied to a liquid crystal projector for displaying a projected image on a screen, and here, the structure of the fixing portion of the spectral dichroic mirror and the combining dichroic mirror will be described. FIG. 1 is a front view of the fixed portion of the dichroic mirror.
Is a sectional view taken along the line II-II, and FIG. 3 is a perspective view thereof. In the figure, reference numeral 1 denotes a dichroic mirror, and this dichroic mirror 1 is fixed by a mounting base 2 made of synthetic resin. In this case, in the center of the mount 2,
An opening 2a is provided, and the dichroic mirror 1 is fixed so as to cover the opening 2a.

In this example, projections are formed around the opening 2a (two locations on the upper side and one location on the lower side), and the tips of the projections serve as the reference plane 3. That is, the state in which the dichroic mirror 1 is in contact with each of the reference surfaces 3 is set so as to be the optimum fixed position. Further, a holding portion 4 is provided at the left and right ends of the opening 2a, and a tip portion of the holding portion 4 is slightly projected inward so as to be close to the back surface of the fixed dichroic mirror 1. .. Also, with the dichroic mirror 1 placed at a fixed position, the dichroic mirror 1
Positioning pins 5 are erected at positions contacting the lower end surface and the left and right end surfaces.

The mounting base 2 constructed in this way
The dichroic mirror 1 is fixed to the main frame 7 of the liquid crystal projector device with the screw 8.

When fixing the dichroic mirror 1 to the mounting base 2, the dichroic mirror 1 is inserted from the upper side until it comes into contact with the positioning pin 5. In this state, all the reference planes 3 are brought into contact with the surface of the dichroic mirror 1, and while maintaining this contact state, the end portions of the dichroic mirrors 1 near the respective reference planes 3 and the mount 2 are exposed to ultraviolet rays. A cured resin adhesive (UV adhesive) 6 is used for adhesion and fixation. The ultraviolet curable resin adhesive 6 is an adhesive that is cured by irradiation of ultraviolet rays and can be cured in a relatively short time. In addition, at the time of fixing work, the adhesive is prevented from rotating between the reference surface 3 and the dichroic mirror 1.

When the adhesive 6 is cured,
The dichroic mirror 1 is fixed to the mounting base 2, and the dichroic mirror 1 is fixed to a predetermined position in the liquid crystal projector.

The other parts are constructed similarly to the conventional liquid crystal projector.

By fixing the dichroic mirror in this manner, it is possible to fix the dichroic mirror with high accuracy in a simple assembly process. That is, since the mounting position of the dichroic mirror is determined by the contact with the reference surface 3 of the mounting base 2,
The position is determined with extremely high accuracy by fixing with the ultraviolet curing resin adhesive 6 while maintaining this contact state. Further, since the fixing is performed with the ultraviolet curable resin adhesive 6, there is almost no possibility that the position will be displaced due to a change in time, and the initial accuracy can be maintained even after long-term use. Further, even if the dichroic mirror comes off, the pressing portion 4 holds the dichroic mirror, so that the dichroic mirror can be prevented from being damaged. However, in the case of this example, the dichroic mirror rarely comes off in the normal use state.

In the above embodiment, the dichroic mirror for spectroscopy and the dichroic mirror for synthesis are applied to the fixed parts, but it is needless to say that the invention can be applied to the fixed parts of other mirrors in the liquid crystal projector.

[0022]

According to the present invention, the mirror is securely fixed by the ultraviolet-curing resin adhesive while the mirror fixing accuracy is ensured by the reference surface, and the optical system of the liquid crystal projector is highly accurate with a simple structure. It becomes possible to do something.

[Brief description of drawings]

FIG. 1 is a front view showing the vicinity of a fixed portion according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a perspective view showing the vicinity of a fixed portion according to an embodiment.

FIG. 4 is a cross-sectional view showing an example of a liquid crystal projector.

FIG. 5 is a front view showing the vicinity of a conventional mirror fixing portion.

FIG. 6 is a cross-sectional view showing the vicinity of a conventional mirror fixing portion.

[Explanation of symbols]

 1 Dichroic mirror 2 Mounting base 3 Reference surface 4 Holding part 5 Positioning pin 6 UV curable resin adhesive

Claims (1)

[Claims] 1. The illumination light is divided into a plurality of color components by a spectroscopic mirror, the respective color components are applied to different liquid crystal panels to be transmitted therethrough, and the light transmitted through the respective liquid crystal panels is combined. In a liquid crystal projector for forming a system of rays by a mirror and projecting the rays on a screen, an ultraviolet curable resin in a state where at least one of the spectroscopic mirror and the synthesizing mirror is in contact with a predetermined reference surface. A liquid crystal projector that is fixed by adhering with a system adhesive.