JPH0792563A - Light source device - Google Patents

Abstract

PURPOSE:To obtain parallel beams by a small light source device suitable for a liquid crystal projector, etc. CONSTITUTION:In the light source device provided with a lamp 2 emitting light and a reflector reflecting the light coming from the lamp 2, a ring-shaped lens 3 transmitting the light coming from the lamp 2 to the outer peripheral side is disposed to surround the circumpherence of the lamp 2, and further a conical reflector 4 reflecting the light transmitted through the lens 3 in the vertical direction and turning it into the parallel beams is disposed to surround the lens 3. Then, a lens 5 transmitting the light coming from the lamp 2 to the front side and turning it into the parallel luminous fluxes is disposed on the front side of the lamp 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source device for use in a liquid crystal projector or the like, which is small in size and capable of obtaining parallel light.

[0002]

2. Description of the Related Art Light from one light source is converted into an R (red) component,
The light is decomposed into three lights of G (green) component and B (blue) component, and the corresponding three liquid crystal display panels are irradiated, and each liquid crystal display panel is decomposed into three colors of R, G, and B and displayed. There is a liquid crystal projector in which a color image such as a television image thus generated is combined by reflection and transmission and enlarged and projected on a screen by one projection lens.

Conventionally, a light source used for a liquid crystal projector or the like uses a parabolic reflector. For example, a parabolic reflector 41 having a structure shown in FIG. The emitted light flux was made into a parallel light flux by reflection.

[0004]

However, when the parabolic reflector 41 shown in FIG. 4A is used, there is a drawback that the depth becomes large. In addition, FIG.
As shown in FIG. 3, when the parabolic reflector 42 having the same diameter and a small depth is used, there is a drawback that the utilization efficiency of the light flux from the lamp 40 is reduced.

Therefore, an object of the present invention is to provide a small-sized light source device suitable for a liquid crystal projector or the like and capable of obtaining parallel light.

[0006]

In order to solve the above problems, the present invention provides a light source device including a lamp that emits light and a reflector that reflects the light emitted from the lamp. And a ring-shaped lens that transmits the light emitted from the lamp to the outer peripheral side, and the ring-shaped lens that is disposed so as to surround the periphery of the ring-shaped lens in the right angle direction. A conical reflector that reflects the light into a parallel light flux, and a lens that is disposed on the front side of the lamp and that transmits the light emitted from the lamp to the front side to convert the light into a parallel light flux are provided.

[0007]

A part of the luminous flux emitted from the lamp is made into a parallel luminous flux by the surrounding ring-shaped lens and the conical reflector, and another part is made into a parallel luminous flux by the front lens.

[0008]

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

First, in FIG. 1 showing an internal structure of a liquid crystal projector as an example to which the light source device according to the present invention is applied, reference numeral 1 comprises a lamp 2, a ring-shaped lens 3, a conical reflector 4 and a lens 5 on the front side. Light source, 11 is B
Dichroic mirror for reflection, 12 for R transmission dichroic mirror, 13 for image reflection mirror, 14 for image reflection mirror, 15 for B transmission dichroic mirror, 16 for R transmission dichroic mirror, 21 for R liquid crystal display panel, 22 Is a liquid crystal display panel for G, 23 is a liquid crystal display panel for B, and 25 is a projection lens.

In this liquid crystal projector, the lamp 2 of the light source 1 emits white light, passes through a ring-shaped lens 3 that surrounds the light, and is reflected by a conical reflector 4 that surrounds the light, and the lens 5 on the front side. The light flux that has passed through the dichroic mirrors 11 and 12 is decomposed in the order of B, G, and R, and is guided to the respective liquid crystal display panels 21, 22, and 23 by using the reflection mirror 13, and the respective liquid crystals. The images of the respective color components transmitted through the display panels 21, 22, 23 are combined by the reflection mirror 14 and the dichroic mirrors 15, 16 and guided to the projection lens 25 to magnify and project the color image.

In the above, the light source 1 is shown in FIG. 2 and FIG.
As shown enlarged, a ring-shaped lens 3 arranged so as to surround the periphery of the lamp 2, a conical reflector 4 arranged so as to surround the periphery of the ring-shaped lens 3, and a front side of the lamp 2. And the lens 5 disposed in the. The lamp 2 is a discharge lamp such as a metal halide lamp in the illustrated example.

That is, the ring-shaped lens 3 is a cylindrical lens whose focal point is the bright spot of the lamp 2 and whose luminous flux from the lamp 2 is perpendicular to the optical axis. Further, the conical reflector 4 has an angle of 45 ° with respect to the optical axis of the reflection surface on the inner peripheral side thereof, and reflects the light transmitted through the ring-shaped lens in the direction perpendicular to the front side to form a parallel light flux along the optical axis. It is a frustoconical tubular shape with the central part removed. The lens 5 on the front side is a lens that focuses the bright spot of the lamp 2 and converts the light emitted from the lamp 2 into a parallel light flux along the optical axis.

Since the light source 1 is configured as described above, of the light emitted from the lamp 2, the light in the direction intersecting the optical axis passes through the surrounding ring-shaped lens 3 and becomes a light flux perpendicular to the optical axis.
Further, it is reflected toward the front surface side by the conical reflector 4 around it and becomes a parallel light beam along the optical axis. Further, the light emitted from the lamp 2 to the front side passes through the lens 2 provided on the front side and becomes a parallel light flux along the optical axis.

In this way, the surrounding light flux, which is a part of the light flux emitted from the lamp 2, is made into a parallel light flux by the ring-shaped lens 3 and the conical reflector 4, and the remaining light flux that comes out forward is the lens on the front side. Since it is made to be a parallel light flux by 5, it is suitable for use in a liquid crystal projector,
The depth of the light source 1 can be reduced to reduce the size.

Further, according to the configuration of the embodiment, the light emitted from the lamp 2 to the surroundings is once reflected by the ring-shaped lens 3 as parallel light by the 45 ° conical reflector 4.
The incident angles on the reflector are the same, and therefore, there is an advantage that color unevenness due to the reflector is eliminated.

By the way, in the above embodiments, the luminous flux emitted from the lamp 2 was not used, but for example, a spherical reflector centered on the bright spot of the lamp 2 is provided behind the ring lens 3. For example, since the luminous flux emitted from the lamp 2 is reflected to the front side by the spherical reflector and is effectively utilized, the depth dimension is somewhat increased, but the advantage that the utilization efficiency of the luminous flux of the lamp can be improved is obtained. . Therefore, in this way, a spherical reflector centered on the bright spot of the lamp 2 may be provided behind the ring-shaped lens 3.

In the above embodiments, the light source device for the liquid crystal projector is used. However, the present invention is not limited to this, and a light source device used for another projector device or the like may be used. Further, the type of the lamp is also arbitrary and can be appropriately changed.

[0018]

As described above, according to the light source device of the present invention, a part of the luminous flux emitted from the lamp is made into a parallel luminous flux by the surrounding ring lens and the conical reflector, and the other part is made. Since the front-side lens is configured to form a parallel light flux, the size can be reduced as compared with the case of using the conventional parabolic reflector.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an internal configuration of a liquid crystal projector as an example to which a light source device according to the present invention is applied.

FIG. 2 is an enlarged plan view of a main part fracture showing a light source device according to the present invention.

FIG. 3 is an exploded perspective view showing components of the light source device.

4A and 4B show a parabolic reflector of a conventional light source device, wherein FIG. 4A is a sectional view when the depth is large, and FIG. 4B is a sectional view when the depth is small.

[Explanation of symbols]

 1 light source 2 lamp 3 ring lens 4 conical reflector 5 front lens 11, 12, 15, 16 dichroic mirror 13, 14 image reflection mirror 21, 22, 23 liquid crystal display panel 25 projection lens

Claims (1)

[Claims] 1. A light source device comprising a lamp that emits light and a reflector that reflects the light emitted from the lamp, wherein the light source device is disposed so as to surround the periphery of the lamp, and the light emitted from the lamp is on the outer peripheral side. A ring-shaped lens that passes through the ring-shaped lens, a conical reflector that is arranged so as to surround the ring-shaped lens and that reflects the light that has passed through the ring-shaped lens in a perpendicular direction into a parallel light beam, A light source device, comprising: a lens, which is disposed on the front surface side and transmits the light emitted from the lamp to the front surface side to form a parallel light flux.