JPH09259620A - Lighting system and liquid crystal image projector using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct light rays from respective end parts of a filament main body or a lamp main body of a light source in a lighting system toward the directions in which a prescribed light grain is obtained, improve the utilization efficiency of light of the light source in order to obtain brighter luminance, and at the same time to make projected images by a liquid crystal image projector apparatus using the lighting system brighter and easy to be observed. SOLUTION: This lighting system has a correcting and reflecting part B provided with conical reflecting plates 21 having one or a plurality of reflecting faces 22 in the inner face and opened wider toward illumination direction along the direction of an optical axis of the light source part A. In this liquid crystal image projector apparatus, at least a condenser 3, a liquid crystal display panel 5, a projection lens 6 are placed in this order in the front face of the lighting system in the illumination direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device such as a backlight for illuminating an optical display device such as a display for advertisement / information display, a liquid crystal display device, and the like, and a liquid crystal image projector device using the same.

[0002]

2. Description of the Related Art Illumination devices such as a backlight for illuminating an optical display device such as a display for advertisement / information display and a liquid crystal display device from the back surface are conventionally provided with a light source lamp 1 (light emitter) as shown in FIG. And a reflector 2 as a spherical concave mirror having the light source lamp 1 arranged at the focal point.

The light emitted to the rear, side and front of the light source lamp 1 is reflected by the reflecting plate 2 and emitted as parallel light Lp to the front in the illumination direction, and the light emitted from the other light source lamps 1 is reflected. It is directly emitted to the front without using the plate 2 and is used as illumination light.

When the illumination light from the above conventional illumination device is used as the illumination light for magnifying projection of a transmissive illumination type liquid crystal image (video) projector device (liquid crystal display panel), as shown in FIG. A condenser lens 3 (a condenser Fresnel lens sheet or a convex lens) is arranged on the front surface of the illumination device in the illumination direction, and the parallel light Lp from the illumination device is
The liquid crystal display panel 5 (in the case of a color liquid crystal display panel, a converging illumination light L ₁ which is transmitted through the liquid crystal display panel 5 through the condenser lens 3 and converged so as to be incident on the optical center of the projection lens 6 is A color filter 4 is provided between the light lens 3 and the panel 5).

The convergent illumination light L ₁ (convergent projection light) incident on the optical center of the projection lens 6 is emitted as enlarged projection light L ₂ from the lens 6 and a predetermined projection screen (not shown) in front of it is emitted. Is a projection screen sheet of, for example, a reflection type or a transmission type.

Particularly, in the conventional illuminating device used for the projection illumination of the liquid crystal video projector device, the light emitted from the filament main body (light emitting portion) of the light source lamp 1 such as a light bulb is reflected by the reflecting plate 2 which is a concave mirror. Is reflected.

The filament of the light source lamp 1 is composed of the reflector 2
Although it is arranged in a space corresponding to the focal point of the spherical concave mirror (point at a distance of 1/2 of the spherical curvature radius), a light-diffusing (scattering) translucent cover that covers the filament body or the filament. Since the main body of the light source lamp 1 including the body (made of glass or plastic) has a predetermined width and is not a complete point light emitter, the central portion of the filament arranged at the focal point of the spherical concave mirror is the reflector plate 2. Although reflected and emitted as substantially parallel light Lp to the front, the light emitting point at the end of the filament body (or the lamp body) is displaced from the focal point of the concave mirror.
The light Ld from the end portion does not become parallel light and is emitted as diverging / converging light Ld1 (loss light) in different directions, so that the light source lamp 1 as a whole cannot obtain parallel light. There is a drawback in that the efficiency of use is not good due to the loss of light as an illumination device.

Although not shown, when an elliptical concave mirror (having a first focus and a second focus) is used as the reflector 2, the light source lamp 1 corresponds to the first focus of the concave mirror. The light source lamp 1 is arranged in a space, is reflected by the reflection plate 2, and is emitted so as to pass through the front second focal point.
The light is focused on the projection lens 6 by the condenser lens 3 or focused on the projection lens 6 directly arranged in the space corresponding to the second focal point. In this case as well, the light of The emission point at the end of the filament body or lamp body is displaced from the first focus of the concave mirror, so
Since the light is emitted in a direction different from the focus, there is a drawback that light loss occurs as an illuminating device and utilization efficiency is not good.

An object of the present invention is to correct (correct) the light from the ends of the filament main body or the lamp main body of the light source in the illuminating device so as to obtain a predetermined optical gain, thereby improving the utilization efficiency of the light from the light source. It is to improve the brightness and obtain brighter illumination, and to make it easier to observe a projected image by a liquid crystal image projector device such as a liquid crystal video projector device using the above illumination device in a brighter manner.

[0010]

Means for Solving the Problems A first invention of the present invention is:
A frustoconical reflection having a front surface of the light source section A and one or more reflecting surfaces 22 having an opening in a direction that expands in the illumination direction along the optical axis direction of the light source section A as an inner surface. Board 2
The lighting device is characterized in that a correction reflection part B having the number 1 is provided.

A second aspect of the present invention is characterized in that at least a condenser lens, a liquid crystal display panel and a projection lens are arranged in this order on the front surface in the illumination direction of the illumination device of the first aspect. Is a liquid crystal image projector device.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION [Regarding Light Source Section] The illumination device of the first invention will be described below in detail according to the embodiment. FIG. 1 is a side sectional view of the illumination device of the first invention. Reference numeral 11 denotes a light source lamp (light emitter) main body, 12 denotes a concave reflecting plate having a spherical concave mirror surface, 1
Reference numeral 2a is a reflecting surface which is a spherical concave mirror surface, and is composed of a light source section A for illumination by the light source lamp 11 and the concave reflecting plate 12.
Is configured.

The light source lamp 11 is arranged at the focal point of the concave reflecting plate 12 (the distance from the reflecting surface is 1/2 the radius of curvature of the spherical surface), and the light emitted from the lamp 11 is concave reflecting surface 12a. After being reflected by, the light source unit A irradiates forward with illumination light that is substantially parallel to the optical axis S (optical axis passing through the center of curvature) of the concave mirror surface.

[Correction Reflecting Section] As shown in FIG. 1, a correction reflecting section B in the shape of a truncated cone is provided in the front part of the light source section A with its center line on the optical axis S of the light source section A. They are arranged so as to be matched with each other or integrally or detachably attached.

The correction reflector B is a truncated cone-shaped reflector 2
1, the inner surface of the reflection plate 21 is a single reflection surface 22 having a shape that opens in a direction in which the light source section A expands in the illumination direction along the optical axis S direction (a cone that covers the entire inner surface of the circumference). It has a single cylindrical reflecting surface).

[Illumination by Illumination Device] In the illumination device of the present invention, as shown in FIG. 1, from the central portion of the main body of the light source lamp 11 (filament light emitting body) arranged at the focal point of the spherical concave mirror 12. The emitted light is reflected by the concave mirror 12 and radiated forward as parallel light Lp, but the light source lamp 11 (filament light emitter)
The light Ld emitted from the end portion of the main body is at a position displaced from the focal point of the spherical concave mirror 12, and therefore is reflected by the spherical concave mirror 12 and is emitted forward as diverging / converging light Ld1 other than the parallel light L.

Here, the divergent light refers to light that escapes outward with respect to the optical axis S in the illumination direction (the common optical axis of the reflecting plate 2 of the spherical concave mirror and the reflecting plate 21 having the shape of a truncated cone tube) and is a convergent light. Means light that enters in the direction of the optical axis S.

The diverging / converging light Ld1 other than the parallel light L emitted from the light source section A of the illumination device of the present invention is the light source section A.
Of the correction reflection portion B in the front part of the correction reflection portion B, and the light emitted from the correction reflection portion B after being reflected by the reflection surface 22 of the truncated conical cylindrical reflection plate 21 and the correction reflection portion directly without entering the reflection surface 22. It is the light emitted from B.

[Regarding Optical Path Correction by Correcting Reflecting Section] The correcting reflecting section B of the illuminating device of the present invention includes the truncated conical tubular reflecting plate 21 of the correcting reflecting section B of the diverging / converging light Ld1 other than the parallel light L. This is for correcting the optical path of the light emitted from the correction reflection section B after being reflected by the reflection surface 22 so that the illumination light is as parallel to the optical axis S as possible.

For example, as shown in FIG. 1, the reflector plate 1 of the light source lamp 11 arranged at the focal point of the spherical concave mirror reflector plate 12.
The light Ld emitted from the end of the filament light emitting body at a position slightly deviated from the focal point of 2 is reflected by the spherical concave mirror reflector 12 to become divergent light Ld1 following the divergent light path.

The divergent light Ld1 is incident on the reflecting surface 22 which is arranged (tapered) in a direction that expands forward in the illumination direction of the correction reflector B, and the divergent light path of the divergent light Ld1 is in the converging direction. Is corrected in the direction parallel to the optical axis S to become the correction light Lp1. The correction light that is incident on the reflecting surface 22 and whose optical path is corrected may be the primary reflected light that is directly incident on and reflected by the reflecting plate 12 (or the light source lamp 11) on the reflecting surface 22, or the primary reflection thereof. The light may be secondary reflected light or multi-order reflected light that is reflected by another opposing reflecting surface 22.

[Reflector Plate of Correcting Reflecting Part Having Multi-Reflecting Surface] FIG. 2 is a side sectional view showing another embodiment of the illuminating device of the present invention, which is a truncated cone of the correcting reflecting part B. The shape of the reflecting surface 22 on the inner surface of the circular reflector 21 is multifaceted.

The light source portion A is formed on the inner surface of the truncated cone-shaped reflecting plate 21.
A multi-faceted reflecting surface 22 (a multi-faceted reflecting surface formed by repeating a plurality of truncated cone cylinders over the entire inner surface of the circumference) that is open in a direction that expands toward the illumination direction along the optical axis S direction of I have it.

As shown in FIG. 2, the diverging / converging light Ld1 other than the parallel light emitted from the light source lamp 11 of the light source section A and reflected by the reflecting plate 12 is reflected by each of the reflecting surfaces of the reflecting surface 22 formed in multiple surfaces. (For example, the light is reflected by the reflection surfaces 22a, 22b, and 22c), and the light path is corrected (corrected) in the direction approaching the optical axis S as parallel light or convergent light, and the correction light Lp1 is emitted in front of the correction reflection portion B. To be done.

The reflective surface 22 shown in FIG.
3 has a shape in which three reflecting surfaces 22a, 22b, 22c each having a circular truncated cone shape and having the same inner diameter and length are connected in the illumination optical axis S direction.

In the present invention, the reflecting surfaces do not necessarily have to have the same inner diameter and length, and for example, the inner diameter may be gradually increased in the illumination direction.
Alternatively, their length may be different.

Next, the liquid crystal image (video) projector device of the second invention will be described below in detail according to the embodiments.

FIG. 2 is a side cross-sectional view of the liquid crystal image projector device. An optical device for enlarging and projecting a liquid crystal image is provided on the front part of the illuminating device (the light source unit A and the correction reflecting unit B) of the first invention described above. It is equipped with system C.

[Regarding Optical System] The optical system C includes a condenser lens 3, a liquid crystal display panel 5, and a projection lens 6, which are arranged in this order.

Further, when displaying a monochrome image, the liquid crystal display panel 5 is used alone, and when displaying a color image, the liquid crystal display panel 5 is provided with the color filter 4.

The condensing lens 3 may be a convex lens or a Fresnel lens sheet for condensing.

[Illumination Light by Illumination Device] As shown in FIG. 2, the parallel light Lp emitted from the illumination device (first invention) by the light source unit A and the correction reflection unit B and the correction light approximate to the parallel light The irradiation light from Lp1 passes through the condenser lens 3 and becomes focused illumination light L1 that is focused on the lens center of the projection lens 6.

[Optical System for Enlarging and Projecting] The focused illumination light L1 that has passed through the condenser lens 3 is the liquid crystal display panel 5
After passing through (or the color filter 4 and the liquid crystal display panel 5) and entering the projection lens 6 as projection image light of the image displayed on the liquid crystal display panel 5, the enlarged projection image light L2
Is projected on a projection screen (not shown) or the like.

[0034]

The illuminating device of the present invention is an illuminating light emitted from a light source lamp, and is particularly a loss light among diverging / converging light other than parallel light reflected by a reflecting plate having a spherical concave mirror surface. The light path of the illumination light is changed to a direction close to parallel light by the correction reflector so that it can be corrected so as to follow the parallel light path and the light path close to parallel light. There is an effect that various lighting is possible.

Further, the liquid crystal image protractor device of the present invention is provided with the above-mentioned illuminating device, and is used for displaying a liquid crystal image by illuminating light which suppresses the loss of light which is corrected to follow the parallel light and the optical path which approximates the parallel light as much as possible. There is an effect that the optical system can be efficiently illuminated and the enlarged projection image on the projection screen or the like can be observed brighter and easier.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a lighting device of the present invention.

FIG. 2 is a side sectional view showing another embodiment of the lighting device of the present invention.

FIG. 3 is a side sectional view illustrating a liquid crystal image projector device of the present invention.

FIG. 4 is a side sectional view illustrating a conventional illumination device and a liquid crystal image projector device using the same.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source lamp 2 ... Reflective plate of spherical concave mirror surface 2a ... Reflective surface 3 ... Condenser lens 4 ... Color filter 5 ... Liquid crystal display panel 6 ... Projection lens 11 ... Light source 12 ... Reflector plate 21 ... Reference numeral 22 ... Reflecting surface 22a, 22b, 22c ... Respective conical reflecting surface L1 ... Focused light L2 ... Projecting light Lp ... Parallel light Ld ... Edge light Ld1 ... Divergence / convergence light after reflection Lp1 ... Correction light

Claims (2)

[Claims] 1. The front surface of the light source section A has, on its inner surface, one or a plurality of reflecting surfaces 22 each having a shape that is opened in a direction that expands in the illumination direction along the optical axis direction of the light source section A. An illuminating device characterized in that a correction reflector B having a truncated cone tubular reflector 21 is provided. 2. A liquid crystal image projector device in which at least a condenser lens, a liquid crystal display panel and a projection lens are arranged in this order on the front surface in the illumination direction of the illuminating device according to claim 1.