JP2000338600A - Projecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize the whole of a projecting device by shortening a color filter for color resolving in the radial direction and also shortening the optical path of a projection lens in the optical axis direction. SOLUTION: This is a projecting device 1 projecting a video formed by radiating projected light from a light source unit 2 on a video display device 36 through a color filter 3a, a mixing optical device 4 and a condensing optical device 35 on a screen by the projection lens 37. In this case, the color filter 3a is constituted of a reflection type color filter to reflect the projected light from the light source unit 2 to the mixing optical device 4, and is arranged so that a filter reflection surface 3a1 is inclined to the light source unit 2 and the optical axis of the mixing optical device 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a projection apparatus which performs color time division by a color wheel (color filter) and displays a color image on a screen.

[0002]

2. Description of the Related Art In general, as a projection device of this type, light from a light source is supplied to a rotating color filter through an RBG (red, blue, red).
2. Description of the Related Art There is known a color time-division type video apparatus that transmits as separated light of green color and irradiates each of the transmitted lights onto an image display device to enlarge and project an image formed on a screen by a projection lens.

Conventionally, as this type of projection device, one shown in FIG. 3 has been employed. This will be described with reference to the figure. In FIG.
Light source unit 32, cooling fan 33, color separation filter unit 34, condensing optical element 35, video display device 3
6 and a projection lens 37.

The light source unit 32 has a lamp light source 32a and a reflecting mirror 32b, and is housed in an apparatus housing 38. Thus, when the lamp light is emitted from the lamp light source 32a, the lamp light is reflected by the reflecting mirror 32b, and the reflected light is applied to the color separation unit 34.

[0005] The cooling fan 33 comprises an axial fan rotated by a fan motor (not shown), and is arranged behind the light source unit 32. Thus, when the cooling fan 33 rotates, an airflow toward the light source unit 32 is formed.

The color separation filter unit 34 has a color filter 34 a rotated by a wheel motor 39, is disposed in front of the light source unit 32 (in the direction of projection of lamp light by the reflecting mirror 32 b), and Motor bracket (not shown) on engine bottom (chassis)
Is stored through. Thereby, the light source unit 3
The red light, the blue light and the green light of the lamp light from 2 pass through each filter section of the color separation filter unit 34.

The condensing optical element 35 has a condenser lens group 35a and a reflecting mirror 35b. Thereby, the color separation filter unit 34 and the video display device 3
6 are optically coupled. Condenser lens group 35a
Is disposed in front of the color separation filter unit 34 and is housed in the device housing 38. The reflecting mirror 35b is
It is disposed in front of the condenser lens group 35a and is mounted on a chassis in the device housing 38.

The image display device 36 is composed of a light-reflection type liquid crystal display device, and is disposed at the top of the engine in the apparatus housing 38. The projection lens 37 is disposed in front of the video display device 36 and is held in the device housing 38 with a part thereof being exposed to the outside. As a result, the image from the image display device 36 is transmitted through the projection lens 37 and projected on a screen (not shown).

The image display (color image display by the color time division method) by the projection device having the above-described configuration is performed as follows. First, the lamp light emitted from the lamp light source 32a is reflected toward the color separation filter unit 34 by the reflecting mirror 32b.

Next, the reflected light passes through the color filter 34a of the color separation filter unit 34, and the transmitted light irradiates the video display device 36 via the condenser lens group 35a and the reflecting mirror 35b. At this time, when the color filter 34a rotates and the red light, the blue light, and the green light pass through the corresponding filter sections, each image is formed on the micro mirror of the video display device 36.

Then, an image from the image display device 36 is enlarged and projected on a screen via the projection lens 37. In this way, a color image is displayed on the screen.

By the way, personal computers in recent years have been widely used due to their high functionality and low cost, and the use of electronic presentations has been widespread. Accordingly, the necessity of a projection apparatus having good projection performance has been increased. ing. In view of this, there has been proposed a projection device of this type in which a mixing optical element (not shown in FIG. 3) is arranged in a device housing 38.

[0013]

However, in the conventional projection apparatus, since the color separation filter unit 34 is a transmission type filter unit, if the mixing optical element is simply arranged on the optical path in the apparatus housing 38. In addition, not only the size of the color separation filter unit 34 increases in the radial direction, but also the optical path in the direction of the optical axis of the projection lens 37 increases.

Japanese Patent Application Laid-Open Nos. Hei 8-21977 and Hei 10-78550 each disclose "illumination control apparatus and control method for image display system" and "method for emphasizing a strong white display area in a sequential DMD video system." Prior art is disclosed as a "system", but the above-mentioned problem has not been solved.

The present invention has been made in view of such circumstances, and it is possible to shorten the color separation color filter in the radial direction and shorten the optical path in the optical axis direction of the projection lens. It is an object of the present invention to provide a projection device capable of reducing the size of the entire device.

[0016]

According to a first aspect of the present invention, there is provided a projection apparatus, wherein a projection light from a light source unit is supplied to a video display device by a color separation color filter and a mixing optical system. A projection device for projecting an image formed by irradiating the light through an element and a condensing optical element onto a screen by a projection lens, wherein a color filter for color separation is an optical device for mixing light projected from a light source unit. The color filter is a reflection type color filter that reflects light to the element, and the filter reflection surface is arranged to be inclined with respect to the optical axes of the light source unit and the mixing optical element. Therefore, the projection light from the light source unit is reflected by the color filter for color separation, and the reflected light is applied to the video display device via the mixing optical element and the condensing optical element to form a color image. A color image is projected on a screen by a projection lens.

According to a second aspect of the present invention, in the projection device according to the first aspect, the image display device comprises a liquid crystal display device. Therefore, the projection light from the light source unit is reflected by the color filter for color separation, and the reflected light is applied to the liquid crystal display device via the mixing optical element and the condensing optical element to form a color image. A color image is projected on a screen by a projection lens.

The third aspect of the present invention is the first or second aspect.
In the projection device described above, the mixing optical element is arranged between the condensing optical element and the color separation color filter. Therefore, when the projection light from the light source unit is reflected by the color filter for color separation, the reflected light sequentially passes through the mixing optical element and the condensing optical element and irradiates the image display device.

According to a fourth aspect of the present invention, in the projection device according to the first, second or third aspect, the mixing optical element comprises a rod lens. Therefore, the projection light from the light source unit is reflected by the color filter for color separation, and the reflected light irradiates the image display device via the rod lens and the condensing optical element to form a color image. Is projected on the screen by the projection lens.

According to a fifth aspect of the present invention, in the projection device according to the first, second or third aspect, the mixing optical element comprises a fly-eye lens. Therefore, the projection light from the light source unit is reflected by the color filter for color separation, and the reflected light is radiated to the video display device via the fly-eye lens and the condensing optical element to form a color image. An image is projected on a screen by a projection lens.

According to a sixth aspect of the present invention, in the projection apparatus according to any one of the first to fifth aspects, the mixing optical element and the light source unit are arranged at positions where the respective optical axes are perpendicular to each other. There is a configuration. Therefore, the projection light from the light source unit is reflected by the color separation color filter in a direction perpendicular to the color separation color filter and is incident on the mixing optical element.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings. FIG. 1 is a plan view showing the internal structure of the projection device according to the first embodiment of the present invention. In FIG. 1, the same members as those in FIG. 3 are denoted by the same reference numerals, and detailed description will be omitted. In the figure, a projection device denoted by reference numeral 1 includes a light source unit 2, a cooling fan 33, a color separation filter unit 3, a mixing optical element 4, a condensing optical element 35, a video display device 36, and a projection lens 37. I have.

The light source unit 2 has a lamp light source 2a and a reflecting mirror 2b, and is housed in a device housing 5 which is substantially L-shaped in plan view. Thus, when the lamp light is emitted from the lamp light source 2a, the lamp light is reflected by the reflecting mirror 2b, and the reflected light is applied to the color separation unit 3. The optical axis of the light source unit 2 is located at a position perpendicular to the optical axis of the mixing optical element 4.

The color separation filter unit 3 has a reflective color filter 3a to rotate by the wheel motor 6, projecting a filter reflecting surface 3a ₁ in front of the light source unit 2 (the projection direction of the lamp light by reflecting mirrors 2b) Lens 3
7 (light source unit 2 and mixing optical element 4) are disposed at an angle of 45 ° with respect to the optical axis, and housed in an engine bottom (chassis) in apparatus casing 5 via a motor bracket (not shown). ing. Thus, the red light, the blue light, and the green light of the lamp light from the light source unit 2 are reflected on the mixing optical element 4 by each filter unit (the filter reflection surface 3a ₁ ) of the color separation filter unit 3.

The mixing optical element 4 is composed of a rod lens, and is disposed between the color separation filter unit 3 and the condensing optical element 35. As a result, the reflected light from the color separation filter unit 3 is transmitted to the mixing optical element 4.
When the light enters the inside, mixing is performed by repeating internal reflection. The optical axis of the mixing optical element 4 is located at a position perpendicular to the optical axis of the light source unit 2. As a result, the projection light from the light source unit 2 is reflected by the color filter 3 for color separation in a direction perpendicular to the color filter 3 and enters the mixing optical element 4.

The image display (color image display by the color time division method) by the projection device having such a configuration is performed as follows. First, the lamp light emitted from the lamp light source 2a is reflected by the reflecting mirror 2b toward the color separation filter unit 3.

Next, the reflected light is reflected by the color filter 3a (filter reflection surface 3a ₁ ) of the color separation filter unit 3, and the reflected light is mixed by the mixing optical element 4, the condensing optical element 35 (condenser lens group). 35a, reflecting mirror 35
Irradiate the image display device 36 via b). At this time, when the color filter 3a rotates and the red light, the blue light, and the green light are reflected by the corresponding filter units,
Each image is formed on the micro mirror of the video display device 36.

Then, the color image by the image display device 36 is enlarged and projected on the screen via the projection lens 37. In this way, a color image is displayed on the screen.

Therefore, in the present embodiment, the incidence of the projection light from the optical unit 2 to the mixing optical element 4 is realized by the reflection at the color separation filter unit 3, so that the color separation filter unit 3 is moved in the radial direction. And the optical path in the optical axis direction of the projection lens 37 can be shortened. Further, in the present embodiment, when the reflected light from the color separation filter unit 3 enters the mixing optical element 4, the mixing is performed by repeating the internal reflection, so that the illuminance uniformity can be improved.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 2 is a plan view showing the internal structure of the projection device according to the second embodiment of the present invention.
The same members as those described above are denoted by the same reference numerals, and detailed description thereof will be omitted. In the figure, a projection device indicated by reference numeral 21 includes a light source unit 2, a cooling fan 33, a color separation filter unit 3, a mixing optical element 22, a condensing optical element 35, an image display device 36, and a projection lens 37. I have.

The mixing optical element 22 is composed of a fly-eye lens, and is disposed between the color separation filter unit 3 and the condensing optical element 35. Thus, when the reflected light from the color separation filter unit 3 enters the mixing optical element 22, mixing is performed by repeating internal reflection. The optical axis of the mixing optical element 22 is
The light source unit 2 is positioned at a right angle to the optical axis. Thus, the projection light from the light source unit 2 is reflected by the color separation color filter 3 in a direction perpendicular to the color separation filter 3 and is incident on the mixing optical element 22.

The image display (color image display by the color time division method) by the projection device having the above configuration is performed in the same manner as in the first embodiment. That is, the projection light from the light source unit 2 is reflected by the color filter 3 for color separation,
The reflected light irradiates the video display device 36 via the mixing optical element 22 and the condensing optical element 35 to form a color image, and this color image is projected on a screen by the projection lens 37.

Therefore, in the present embodiment, the light path can be shortened in the optical axis direction of the projection lens 37, the color separation filter unit 3 can be shortened in the radial direction, and the illuminance uniformity can be improved, as in the first embodiment. It is.

It should be noted that the shape of the device housing and the like in the present invention is not particularly limited to the above-described embodiment.

[0035]

As described above, according to the present invention, the color filter for color separation comprises a reflection type color filter for reflecting the projection light from the light source unit to the mixing optical element, and the reflection surface of the filter is a light source. The projection light from the light source unit is reflected by the color filter for color separation because the unit and the optical axis of the mixing optical element are inclined with respect to the optical axis of the unit and the optical element for mixing. A color image is formed by irradiating the image display device with the color image, and the color image is projected on a screen by a projection lens.

Accordingly, the incidence of the projection light from the optical unit to the mixing optical element is realized by the reflection at the color separation filter unit, so that the color separation color filter can be shortened in the radial direction and the projection can be performed. The optical path can be shortened in the optical axis direction of the lens, and the size of the entire device can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing an internal structure of a projection device according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an internal structure of a projection device according to a second embodiment of the present invention.

FIG. 3 is a plan view showing the internal structure of a conventional projection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Projection apparatus 2 Light source unit 2a Lamp light source 2b Reflector 3 Color separation filter unit 3a Color filter 3a ₁ Filter reflection surface 4 Mixing optical element 35 Condensing optical element 35a Condenser lens group 35a Reflector mirror 36 Image display device 37 Projection lens

Claims (6)

[Claims] An image formed by irradiating projection light from a light source unit to a video display device through a color separation color filter, a mixing optical element, and a condensing optical element is used to project an image formed on a screen by a projection lens. A color filter for color separation, wherein the color filter for color separation is a reflection type color filter for reflecting the projection light from the light source unit to the mixing optical element, and a filter reflection surface is provided between the light source unit and the light source unit. A projection device, wherein the projection device is arranged to be inclined with respect to the optical axis of the mixing optical element. 2. The projection apparatus according to claim 1, wherein said video display device comprises a liquid crystal display device. 3. The projection device according to claim 1, wherein the mixing optical element is disposed between the light collecting optical element and the color separation color filter. 4. The projection device according to claim 1, wherein the mixing optical element comprises a rod lens. 5. The projection device according to claim 1, wherein the mixing optical element comprises a fly-eye lens. 6. The projection according to claim 1, wherein the mixing optical element and the light source unit are arranged at positions where the optical axes are perpendicular to each other. apparatus.