JPH0736345Y2 - Polarizing plate adjustment mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a polarizing plate adjusting mechanism capable of obtaining an optimum contrast by adjusting a polarizing plate used in a liquid crystal projector or the like.

<Prior Art> In the following description, a liquid crystal projector will be described as an example of a liquid crystal display device.

FIG. 6 shows a schematic configuration of a liquid crystal projector. The liquid crystal projector is a projector that uses a liquid crystal panel 30 as an image display element and projects a video image or the like on a screen 50 in an enlarged manner by the shutter action of the liquid crystal panel 30.

The light source light L emitted from the light source 10 is reflected forward by a substantially bowl-shaped reflector 11 provided behind the light source 10. The light source light L is condensed by the condenser lens 20 and is incident on the liquid crystal panel 30. This LCD panel 30
The light source light L that has passed through is modulated by the shutter action of the liquid crystal panel 30 in accordance with the video signal. This light source L is
The light enters the projector lens 40 and is focused on the screen 50.

The liquid crystal panel 30 is one in which liquid crystal is sealed by two transparent glass substrates, and an incident side polarization plate 31 and an emission side polarization plate 32 are provided on the incident side and the emission side of the liquid crystal panel 30, respectively. Has been. The polarizing plates 31 and 32 are adhered to the liquid crystal panel 30 and are set so that their polarization directions are orthogonal to each other. In the liquid crystal panel 30 configured as above, the pixel transparency changes according to the input video signal, and functions as a shutter.

Although FIG. 6 shows only one liquid crystal panel 30, three R, G and B liquid crystal panels 30 must be used when displaying a color image.

<Problems to be Solved by the Invention> However, the above-described conventional liquid crystal projector has the following problems.

That is, since the entrance-side polarization plate and the exit-side polarization plate are attached in close contact with the liquid crystal panel, when a high-intensity halogen lamp or metal halide lamp is used as the light source, heat may be accumulated in the liquid crystal panel and the characteristics may deteriorate. There is. In order to solve this, a method of disposing the incident side polarization plate away from the liquid crystal panel has already been implemented. However, in this method, the polarization directions of the incident side polarization plate and the emission side polarization plate are deviated, and it becomes difficult to optimize the contrast of the image enlarged and projected on the screen.

The present invention was created in view of the above circumstances, and an object thereof is to provide a polarizing plate adjusting mechanism for adjusting the position of the polarizing plate so as to optimize the contrast of an image.

<Means for Solving the Problems> A polarizing plate adjusting mechanism according to the present invention is a liquid crystal panel in which liquid crystal is sealed, a light source for giving light source light to the liquid crystal panel, and an incident side polarizing plate attached to the liquid crystal panel. And a polarizing plate adjusting mechanism in a liquid crystal display device having an exit side polarizing plate, the first frame-shaped first frame having a liquid crystal panel attached thereto.
A frame, a substantially frame-shaped second frame to which the incident side polarizing plate is attached, and a second frame that supports the second frame so as to be movable in the plane direction of the incident side polarizing plate with respect to the first frame. A position adjusting part that can be fixed at an appropriate position is provided, and the position adjusting part has a center part which is a center of movement of the incident side polarization plate of the second frame in the plane direction and a center part of the center part. And a pair of fixing portions provided on the same circumference.

<Operation> The positional relationship between the first frame and the second frame is adjusted by the position adjusting unit on the production line.

The liquid crystal panel to which the exit side polarizing plate is adhered and adhered is attached to the first frame, and the glass plate to which the incident side polarizing plate is adhered and adhered is attached to the second frame in the previous step.

Adjust the relative positional relationship of both frames with the position adjustment unit,
When the optimum contrast is reached, the first frame and the second frame
Fix the relative positional relationship with the frame.

<Embodiment> An embodiment according to the present invention will be described below with reference to the drawings.

1 is a front view of a polarizing plate adjusting mechanism according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is an enlarged view of part a of FIG. 2, and FIG. (A) And (b) is a front view and a side view of a 1st frame, and FIG. 5 is a schematic block diagram of a liquid crystal projector. It should be noted that parts and the like that are substantially the same as the conventional ones will be given the same reference numerals for the description.

The polarizing plate adjusting mechanism 60 according to the present embodiment includes a liquid crystal panel 30 in which liquid crystal is sealed, a light source 10 for giving a light source light L to the liquid crystal panel 30, an incident side polarizing plate 31 attached to the liquid crystal panel 30, It is used for a liquid crystal display device having an emission side polarization plate 32.

The polarizing plate adjusting mechanism 60 includes a first frame 61 and a second frame 62.
Further, it has a position adjusting part 63 which can connect both frames 61 and 62 and can adjust the position thereof.

The first frame 61 is formed in a substantially frame shape having a square hole 611 formed in the center thereof, which is slightly smaller than the liquid crystal panel 30, and the upper and lower ends thereof are bent substantially at right angles. Further, a boss 612 having a screw hole is erected on the upper center of the first frame 61, while a boss 613 having a screw hole is erected on the lower left and right ends. The liquid crystal panel 30 to which the emission side polarization plate 32 is adhered and attached is attached to the first frame 61 configured as described above. In this case, the liquid crystal panel 30 is attached to the first frame 61 so that the exit side polarizing plate 32 faces outward.

The second frame 62 is attached to the first frame 61, and is formed in a substantially frame shape smaller than the first frame 61. That is, the liquid crystal panel 30 is provided at the center.
A slightly smaller square hole 621 is formed, and both upper and lower end portions thereof are formed as an upper mounting portion 622 and a lower mounting portion 623 in a substantially crank shape in a side view. An opening 622a is formed at a position where the upper mounting portion 622 corresponds to the boss 612, that is, at the center of the upper mounting portion 622. On the other hand, the lower mounting part 62
3 is a position corresponding to the boss 613, that is, the lower mounting portion 623.
Long holes 623a are formed at both left and right ends of the. This long hole 62
3a is set so as to be located on the virtual circle S when the virtual circle S centered on the opening 622a (shown by the one-dot chain line in FIG. 1) is assumed.

That is, the boss 612 of the first frame 61, the opening 622a of the second frame 62 corresponding to the boss 612, and a stepped screw 631 described later attached to the boss 612 through the opening 622a.
The central part is composed of and. In addition, a pair of bosses 613 of the first frame 61, a pair of elongated holes 623a of the second frame 62 corresponding to the bosses 613, and two screws 632 described later attached to the boss 613 through the elongated holes 623a. And means that the fixed part is configured.

Next, a procedure for attaching the incident side polarization plate 31 to the second frame 62 will be described. The incident side polarization plate 31 is adhered to a transparent glass plate 311 slightly larger than the incident side polarization plate 31, and the glass plate 311 is attached so as to correspond to the square hole 621 of the second frame 62. At this time, the incident side polarization plate 31 is made to face outward.

The position adjusting unit that connects the first frame 61 and the second frame 62 described above will be described.

The position adjusting portion includes a stepped screw 631 corresponding to the boss 612 of the first frame 61 and the opening 622a of the second frame 62, and a screw 632 corresponding to the boss 613 of the first frame 61 and the long hole 623a of the second frame 62. And (but only one screw 632 is shown). The large diameter portion 631a of the stepped screw 631 has a diameter that fits into the opening 622a, and the small diameter portion 631b has a boss 612.
The diameters are set so that they can be screwed into the screw holes.

The adjustment of the positional relationship between the first frame 61 and the second frame 62 by such a position adjusting unit is performed on the production line. The adjustment performed in this production line will be described.

The liquid crystal panel 30 to which the exit side polarizing plate 32 is adhered is attached to the first frame 61, and the glass plate 311 to which the incident side polarizing plate 31 is adhered is attached to the second frame 62 in the previous step.

First, stepped screws 631 replace the second frame 62 with the first frame 61.
Attach to. Then, the second frame 62 is attached so as to be movable in the arrow direction shown in FIG. 1, that is, the plane direction of the incident side polarization plate 31, with the center portion as the center.

Next, the second frame 62 is displaced in the direction of the arrow around the stepped screw 631 so that the optimum contrast can be obtained.

When it is judged that the optimum contrast has been obtained by visual inspection by an inspector or an automatic machine, a screw 632 is screwed into the screw hole of the boss 613 through the long hole 623a, and the second frame 62 is attached to the first frame 61. Fix it. That is, the second frame 62 is fixed to the first frame 61 by the pair of fixing portions described above.

As a result, the relative positional relationship between the polarizing plates 31 and 32 makes it possible to obtain optimum contrast.

Although a liquid crystal projector is used as the liquid crystal display device in the above-described embodiments, the present invention is not limited to this, and the present invention can be applied to other liquid crystal display devices such as a liquid crystal television.

<Effect of Device> According to the polarizing plate adjusting mechanism of the present invention, it becomes possible to adjust the relative positional relationship between the incident side polarizing plate and the emitting side polarizing plate so as to obtain an optimum contrast. .

[Brief description of drawings]

1 is a front view of a polarizing plate adjusting mechanism according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is an enlarged view of part a of FIG. 2, and FIG. (A) And (b) is a front view and a side view of a 1st frame, FIG. 5 is a schematic block diagram of a liquid crystal projector, and FIG. 6 is a schematic block diagram of the conventional liquid crystal projector. 10 …… light source, 30 …… liquid crystal panel, 31 …… incident side polarization plate,
32 …… Ejection side polarizing plate, 60 …… Polarizing plate adjusting mechanism, 61 …… First frame, 62 …… Second frame, L …… Light source light.

Claims (1)

[Scope of utility model registration request] 1. A polarizing plate in a liquid crystal display device comprising a liquid crystal panel in which liquid crystal is sealed, a light source for giving a light source light to the liquid crystal panel, and an incident side polarizing plate and an emitting side polarizing plate attached to the liquid crystal panel. In the adjustment mechanism, a substantially frame-shaped first frame to which the liquid crystal panel is attached, a substantially frame-shaped second frame to which the incident side polarizing plate is attached, and the second frame are the incident side polarizing plate with respect to the first frame. And a position adjusting section for fixing the second frame at an appropriate position, the position adjusting section being a plane direction of the incident side polarization plate of the second frame. A polarizing plate adjusting mechanism, which has a central portion that is a center of movement of the sheet, and a pair of fixing portions that are provided on the same circumference around the central portion.