JPH0675222A - Liquid crystal projector - Google Patents

Abstract

PURPOSE:To provide the liquid crystal projector constituted to eliminate the degradation in resolution and unequal light emission by liquefaction of metal halide sealed in the chip part of a light source. CONSTITUTION:This liquid crystal projector is constituted to condense the light source emitted from the light source 1 having the chip part 9 projecting outward from an outer peripheral surface to an aperture window 4 formed on a rotary mirror 3 by a rotary spheroidal surface mirror 2 and the rotary mirror 3, to collimate this light by a condenser lens 5 and to irradiate the liquid crystal panel with the collimated beams of light obtd. by refracting such collimated beams of light to a central optical axis side by a light refraction plate 6 and having a uniform light quantity. The above-mentioned chip part 9 is constituted by projecting this part in the direction perpendicular to the central optical axial line connecting the center of the light source 1 and the center of the aperture window 4.

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, and more particularly to a liquid crystal projector capable of eliminating deterioration of resolution and unevenness of light emission due to liquefaction of a chip portion of a light source or a sealed gas.

[0002]

2. Description of the Related Art A conventional liquid crystal projector includes a light source 1 and a spheroidal mirror 2 formed on a part of a substantially spheroidal surface having the light source 1 as a focal point, as shown in the configuration diagram of FIG. Of the light emitted from the light source 1 and reflected by the spheroidal mirror 2 while being arranged on the opposite side of the spheroidal mirror 2 with respect to the light source 1 and having a spherical shape centered on the light source 1. A spherical mirror 3 having an opening window 4 opened at a position where most of the light is concentrated, a condenser lens 5 for collimating the light passing through the opening window 4 and emitting the parallel light, and a light emitted from the condenser lens in the central direction. A light refraction plate 6 for refracting and emitting parallel light having a uniform light amount to a liquid crystal panel 8 via a relay lens 7 is provided.

In this liquid crystal projector, the light source 1
The light emitted from is reflected by the spheroidal mirror 2, is focused on the opening window 4 of the spherical mirror 3 arranged facing the spheroidal mirror 2, and is further emitted from the opening window 4.
The light emitted from the opening window 4 is refracted by the condenser lens 5 and emitted as parallel light.

The aperture window 4 reflected by the spheroidal mirror 2
The light blocked by the light source 1 out of the light traveling toward
Since the light does not pass through the condenser lens 5, the amount of light incident on the condenser lens 5 is reduced in a portion between the central optical axis line passing through the light source 1 and the opening window 4 and the ray shown by the alternate long and short dash line in FIG. A dark portion appears on the central optical axis of the light emitted from the light source and its peripheral portion.

Both surfaces of the light refracting plate 6 are formed into parallel conical surfaces which are gradually inclined in the traveling direction of light from the center toward the periphery, and the dark portion disappears by refracting the light around the dark portion to the central optical axis. Then, parallel light having a uniform light quantity is emitted.

The relay lens 7 slightly converges the parallel light emitted from the light refracting plate 6 and having a uniform light amount, and makes the parallel light incident on the liquid crystal panel 8.

In large liquid crystal projectors,
The light transmitted through the liquid crystal panel 8 is enlarged and projected on the display screen by a projection lens (not shown).

As the light source 1, a metal halide lamp excellent in luminance, directivity and uniformity of light emission is often used.

[0009]

In this metal halide lamp, since the tip portion 9 protruding from the outer peripheral surface is formed in the manufacturing process, if this tip portion 9 is used as the light source 1,
As shown in FIG. 4, a part of the light emitted from the light source 1 is scattered by passing through the chip portion 9, and the light having low directivity is emitted.

Further, since the tip portion 9 has a larger surface area than the other portions, the tip portion 9 is cooled more than the other portions and has a low temperature.
Therefore, the metal halide 10 enclosed in the metal halide lamp is condensed and liquefied on the inner surface of the tip portion 9, and the liquefied metal halide 10 further scatters and emits colored light.

Further, as shown in FIG. 5, when the liquefied metal halide 10 accumulates in the lower part of the metal halide lamp, the light passing through the metal halide 10 is also scattered and colored, which is the spheroidal mirror 2. And is reflected by the spherical mirror 3 and emitted from the opening window 4.

When colored light having a low directivity enters the liquid crystal panel 8 in this way, the resolution is lowered and the light emission is uneven, so that the display quality is significantly impaired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a liquid crystal projector capable of eliminating deterioration of resolution and unevenness of light emission due to liquefaction of a chip portion of a light source or a sealed gas. .

[0014]

A liquid crystal projector, which is a premise of the present invention, forms a light source having a tip portion protruding outward from an outer peripheral surface and a part of a substantially spheroidal surface having the light source as a focal point. The spheroidal mirror and the light source are arranged on the opposite side of the spheroidal mirror, and are formed in a spherical shape centered on the light source, and emitted from the light source and reflected by the spheroidal mirror. A spherical mirror with an aperture window that is opened at a position where most of the light is concentrated, a condenser lens that collimates the light that passes through the aperture window, and emits it, and the amount of light that is obtained by refracting the light emitted from the condenser lens toward the center. And a light refraction plate for emitting parallel light to the liquid crystal panel. The first liquid crystal projector of the present invention is premised on such a liquid crystal projector, and in order to eliminate deterioration in resolution and unevenness in light emission due to the chip portion of the light source, a central optical axis line connecting the chip portion to the center of the light source and the center of the opening window. It is characterized in that it is projected in a direction perpendicular to.

In the second liquid crystal projector of the present invention, the central optical axis is arranged horizontally in the first liquid crystal projector of the present invention in order to eliminate deterioration of resolution and unevenness of light emission due to liquefaction of the tip portion of the light source and the enclosed gas. However, the tip portion is projected downward.

The third liquid crystal projector of the present invention reliably eliminates the deterioration of the resolution and unevenness of light emission due to the liquefaction of the tip portion of the light source and the enclosed gas, and enhances the light emission utilization rate of the light source. In the above liquid crystal projector or the second liquid crystal projector, the spheroidal mirror portion and the spherical mirror portion on which the light rays that pass through the tip portion of the light source and are emitted are incident.

The fourth liquid crystal projector of the present invention achieves the above object in the third liquid crystal projector of the present invention, and at the same time, the spheroidal mirror and the spherical mirror are partially omitted due to a dark portion. In order to prevent a reduction in display brightness, the center of the display portion of the liquid crystal panel is deviated from the central optical axis in the protruding direction of the chip portion.

[0018]

In the first liquid crystal projector of the present invention, the tip portion of the light source is projected at a right angle to the central optical axis connecting the center of the light source and the center of the opening window, so that the tip portion is transmitted. The light emitted and reflected by the spheroidal mirror can be applied to the outer peripheral portion of the opening window and blocked by the spherical mirror.

In the second liquid crystal projector of the present invention,
By arranging the central optical axis horizontally and projecting the tip portion downward, the position where the enclosed gas is liquefied in the light source due to the low temperature of the tip portion, the position where the liquefied enclosed gas is accumulated in the light source, and the tip portion Will be located in the same direction with respect to the center of the light source. Then, the light emitted from the light source in this direction can be reflected by the spheroidal mirror to irradiate the outer peripheral portion of the opening window and can be blocked by the spherical mirror.

In the third liquid crystal projector of the present invention,
Since the part of the spheroidal mirror and the part of the spherical mirror on which the light beam that passes through the chip part of the light source is incident are omitted, the light that passes through the chip part of the light source is reflected by the spheroidal mirror and the spherical mirror. There is no possibility of going to the opening window of the spherical mirror.

Further, the light emitted from the side opposite to the tip portion can be reflected by the spheroidal mirror and the spherical mirror and directed toward the opening window.

In the third liquid crystal projector of the present invention, by omitting the portion of the spheroidal mirror and the portion of the spherical mirror, one side edge of the light passing through the condenser lens and the light refracting plate, that is, A dark portion is generated at the edge portion on the side opposite to the chip portion with respect to the central optical axis, and one side portion of the display portion of the liquid crystal projector becomes dark.

On the other hand, in the fourth liquid crystal projector of the present invention, the center of the display portion of the liquid crystal panel is offset from the central optical axis in the protruding direction of the chip portion so that the dark portion is located outside the display portion. In addition, uneven light emission is prevented.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A liquid crystal projector according to an embodiment of the present invention will be specifically described below with reference to FIGS.

A liquid crystal projector according to an embodiment of the present invention has a light source 1 and a rotation formed in a shape of a part of a substantially spheroidal surface having the light source 1 as a focus, as shown in the overall configuration diagram of FIG. The ellipsoidal mirror 2 is arranged on the opposite side of the spheroidal mirror 2 with respect to the light source 1, is formed in a spherical shape with the light source 1 at the center, and is emitted from the light source 1 to be rotated by the spheroidal mirror 2. A spherical mirror 3 having an opening window 4 opened at a position where most of the reflected light is concentrated, a condenser lens 5 for collimating the light passing through the opening window 4 and emitting the parallel light, and a condenser lens 5 emitted from the condenser lens. A light refraction plate 6 that refracts light in the central direction and emits parallel light having a uniform light amount to a liquid crystal panel 8 via a relay lens 7.

The light transmitted through the liquid crystal panel 8 is projected on a display screen (screen) (not shown) in an enlarged manner via a projection lens (not shown). The light source 1 is composed of a metal halide lamp, and has a tip portion 9 protruding from the outer peripheral surface as shown in the configuration diagram of the main portion of FIG.

The central optical axis passing through the center of the light source 1 and the center of the opening window 4 of the spherical mirror 3 is arranged horizontally, and the chip portion 9 is projected downward at right angles to the central optical axis. There is.

The spheroidal mirror 2 is irradiated with light that passes through the tip portion 9 from the center of the light source 1 below the tip portion 9 (light traveling in a hatched area in FIG. 1).
The spherical mirror 3 and the spherical mirror 3 are omitted.

As shown in FIG. 2, the center of the display portion of the relay lens 7 and the liquid crystal panel 8 is at the center of the spheroidal mirror 2.
The light rays reflected by the lower edge of the spherical mirror 3 and passing through the opening window 4 of the spherical mirror 3 are located below the central optical axis so that they are located at the upper end of the display section.

Further, the light transmitted through the liquid crystal panel 8 is enlarged and projected on the display screen by a projection lens (not shown).

In this liquid crystal projector, the light emitted from the light source 1 is reflected by the spheroidal mirror 2 and concentrated on the opening window 4 of the spherical mirror 3 arranged facing the spheroidal mirror 2. The light is emitted from this opening window 4. The light emitted from the opening window 4 is refracted by the condenser lens 5 and emitted as parallel light.

The aperture window 4 reflected by the spheroidal mirror 2
The light blocked by the light source 1 out of the light traveling toward
Since the light does not pass through the condenser lens 5, the amount of light incident on the condenser lens 5 is reduced in the portion between the central optical axis line passing through the light source 1 and the aperture window 4 and the ray shown by the alternate long and short dash line in FIG. A dark portion appears on the central optical axis of the light emitted from the light source and its peripheral portion.

Both surfaces of the light refracting plate 6 are formed into parallel conical surfaces which are gradually inclined in the traveling direction of light from the center toward the periphery, and the dark portion disappears by refracting the light around the dark portion to the central optical axis. Then, parallel light having a uniform light quantity is emitted.

The relay lens 7 slightly converges the parallel light emitted from the light refracting plate 6 and having a uniform light amount, and makes the parallel light incident on the liquid crystal panel 8.

The light transmitted through the chip portion 9 of the light source 1 is directed in the direction perpendicular to the central optical axis, so that the light traveling from the spheroidal mirror 2 to the opening window 4 of the spherical mirror 2 is of the opening window 4. You will pass the furthest position from the center.

Therefore, by opening the opening window 4 to a small size, the light transmitted through the tip portion 9 and emitted, and reflected by the spheroidal mirror 2 is directed to the outer peripheral portion of the opening window 4, whereby a spherical mirror is formed. It is possible to prevent the light, which is blocked by 3 and transmitted through the chip portion 9 and emitted, from reaching the liquid crystal panel 8.

However, in this case, the tip portion 9
Light emitted through the portion on the opposite side is also blocked by the outer peripheral portion of the opening window 4, and the light utilization rate is reduced.

Therefore, in this embodiment, the opening window 4 is widened to the extent that the light emitted after passing through the portion opposite to the tip portion 9 passes through the opening window 4, while passing through the tip portion 9. By omitting the portions of the spheroidal mirror 2 and the spherical mirror 3 to which the emitted light is emitted, the light transmitted through the portion opposite to the tip portion 9 and emitted is the opening window 4.
The light source 1 can be made to enter the liquid crystal panel 8 through the
While increasing the utilization rate of the light emission of, the light transmitted through the tip portion 9 is allowed to escape downward without being reflected by the spheroidal mirror 2 and the spherical mirror 3.

By letting the light that has passed through the chip portion 9 escape downward as described above, there is no possibility that the light that has passed through the chip portion 9 and diffused will enter the liquid crystal panel 8.

Further, when the tip portion 9 is cooled, the vapor of the metal halide 10 is condensed inside the tip portion 9. However, since the tip portion 9 is located below, the condensed metal halide 10 is transmitted. Therefore, the light scattered and colored is also overlapped with the light emitted through the chip portion 9 and escaped downward, and there is no possibility of entering the liquid crystal panel 8.

Further, the metal halide 10 condensed in the light source 1 collects in the lower part in the light source 1, but since the tip portion 9 is located below, the metal halide 10 accumulated in the lower part in the light source 1 is collected. Light that is diffused and colored by passing through is also escaped downward as a part of the light that passes through the chip portion 9 and is emitted, and there is no possibility of entering the liquid crystal panel 8.

In short, according to this embodiment, the light emitted after passing through the portion other than the chip portion 9 can be effectively used, there is no possibility that the resolution will be deteriorated by the scattered light, and the coloring light There is also no risk of color unevenness due to incidence.

In this embodiment, a part of the lower part of the spheroidal mirror 2 and the spherical mirror 3 is omitted so that the light incident area on the upper half of the condenser lens 5 is the upper edge of the conventional incident area. The light is not incident on the upper edge portion of the conventional incident area where the reflected light from the portion corresponding to the missing portion is supposed to be incident, and becomes a dark portion.

If the centers of the display portions of the relay lens 7 and the liquid crystal panel 8 are arranged at the same height as the central optical axis, the upper edge portion of the display portion corresponding to this dark portion may become dark. Then, the centers of the display portions of the relay lens 7 and the liquid crystal panel 8 are reflected by the lower edge of the spheroidal mirror 2 so that the light rays passing through the opening window 4 of the spherical mirror 3 are located at the upper end of the display portion. Since it is deviated below the optical axis, the amount of incident light becomes uniform over the entire surface of the display portion of the liquid crystal panel 8.

[0045]

As described above, according to the first liquid crystal projector of the present invention, the chip portion of the light source is projected in the direction perpendicular to the central optical axis connecting the center of the light source and the center of the opening window. As a result, the light emitted through the chip part and reflected by the spheroidal mirror is irradiated to the outer peripheral part of the opening window, and is blocked by the spherical mirror so that it does not enter the liquid crystal panel. As a result, it is possible to prevent deterioration of resolution due to incidence of the diffused light and the diffused light incident on the liquid crystal panel by transmitting the enclosed gas component such as metal halide condensed on the inner surface of the chip portion.

Further, according to the first liquid crystal projector of the present invention, color unevenness due to incidence of light colored into the liquid crystal panel by transmitting the enclosed gas component such as metal halide condensed on the inner surface of the chip portion. Can be prevented.

According to the second liquid crystal projector of the present invention, in addition to the above-mentioned effects, since the chip portion is located on the lower side, it is condensed in the light source and halogenated in the lower portion of the light source. It is possible to prevent the deterioration of the resolution and the occurrence of color unevenness due to the incident of the colored light which is diffused and colored by permeating the enclosed gas component such as metal into the liquid crystal panel.

According to the third liquid crystal projector of the present invention, in addition to the effect obtained by the first or second liquid crystal projector, the spheroidal mirror which is irradiated with the light emitted through the chip portion is emitted. By omitting the part and the spherical mirror part, it is possible to reliably prevent the light emitted through the chip part from entering the liquid crystal panel, so that the light emitted from the part other than the chip part of the light source is rotated. The light can be reflected by the portion of the ellipsoidal mirror and the spherical mirror to be incident on the liquid crystal panel, and the light emission efficiency of the light source can be increased.

According to the fourth liquid crystal projector of the present invention, in addition to the effect obtained by the third liquid crystal projector, the dark portion generated in the third liquid crystal projector is excluded from the display portion of the liquid crystal panel. It is possible to prevent a part of the display from being dark and the image quality from being deteriorated.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of the present invention.

FIG. 2 is an overall configuration diagram of the present invention.

FIG. 3 is a configuration diagram of a conventional example.

FIG. 4 is an explanatory diagram of a problem to be solved by the present invention.

FIG. 5 is an explanatory diagram of another problem to be solved by the present invention.

[Explanation of symbols]

 1 Light Source 2 Spherical Mirror 3 Spherical Mirror 4 Opening Window 5 Condenser Lens 6 Light Refraction Plate 8 Liquid Crystal Panel 9 Chip Section

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[Procedure amendment]

[Submission date] August 27, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction content]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal projector, and more particularly to a liquid crystal projector capable of eliminating deterioration of resolution and unevenness of light emission due to liquefaction of a chip portion of a light source or a sealed metal halide.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

A liquid crystal projector, which is a premise of the present invention, includes a light source having a tip portion protruding outward from an outer peripheral surface, and a rotation forming a part of a substantially spheroidal surface having the light source as a focal point. The ellipsoidal mirror is arranged on the opposite side of the spheroidal mirror with respect to the light source, is formed in a spherical shape centered on the light source, and a large amount of light emitted from the light source and reflected by the spheroidal mirror is formed. A spherical mirror having an aperture window opened at a position where the portions are concentrated, a condenser lens for collimating the light passing through the aperture window and emitting the parallel light, and refracting the light emitted from the condenser lens in the central direction to reduce the amount of light. And a light refraction plate for emitting uniform parallel light to the liquid crystal panel. The first liquid crystal projector of the present invention is premised on such a liquid crystal projector, and in order to eliminate deterioration in resolution and unevenness in light emission due to the chip portion of the light source, a central optical axis line connecting the chip portion to the center of the light source and the center of the opening window. It is characterized in that it is projected in a direction perpendicular to.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

In the second liquid crystal projector of the present invention,
By arranging the central optical axis horizontally and projecting the tip part downward, the position where the encapsulated metal halide is liquefied in the light source due to the low temperature of the chip part, the position where the liquefied encapsulated metal halide is accumulated in the light source, Also, the position of the chip portion is located in the same direction with respect to the center of the light source.
Then, the light emitted from the light source in this direction can be reflected by the spheroidal mirror to irradiate the outer peripheral portion of the opening window and can be blocked by the spherical mirror.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0046

[Correction method] Change

[Correction content]

Further, according to the first liquid crystal projector of the present invention, color unevenness due to incidence of light colored on the liquid crystal panel by transmitting a liquefied component such as metal halide condensed on the inner surface of the chip portion is prevented. Occurrence can be prevented.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0047

[Correction method] Change

[Correction content]

According to the second liquid crystal projector of the present invention, in addition to the above-mentioned effects, since the chip portion is located on the lower side, it is condensed in the light source and halogenated in the lower portion of the light source. It is possible to prevent the deterioration of the resolution and the occurrence of color unevenness due to the incidence of light colored and diffused by transmitting the liquefied component such as metal into the liquid crystal panel.

Claims (4)

[Claims] 1. A light source having a tip portion projecting outward from an outer peripheral surface, a spheroidal mirror forming a part of a substantially spheroidal surface having the light source as a focal point, and the spheroidal mirror opposite to the light source. A spherical surface having a window formed in a spherical shape centered on the light source and having an opening at a position where most of the light emitted from the light source and reflected by the spheroidal mirror is concentrated. A mirror, a condenser lens that collimates the light that has passed through the aperture window and emits it, and a light refraction plate that refracts the light emitted from the condenser lens toward the center and emits parallel light with a uniform amount of light to the liquid crystal panel. A liquid crystal projector comprising: a liquid crystal projector characterized in that the chip portion is projected in a direction perpendicular to a central optical axis connecting the center of the light source and the center of the opening window. 2. The liquid crystal projector according to claim 1, wherein the central optical axis is arranged horizontally and the chip portion is projected downward. 3. The liquid crystal projector according to claim 1, wherein a portion of the spheroidal mirror and a portion of the spherical mirror that are irradiated with a light beam that passes through the tip portion of the light source and is emitted are omitted. . 4. The liquid crystal projector according to claim 3, wherein the center of the display portion of the liquid crystal panel is offset from the central optical axis in the protruding direction of the chip portion.