JP2002277957A - Projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector which can display an image having no right-left slant even when installed on a base such as a slanting table. SOLUTION: A spatial modulating device 2 which modulates light with a video signal, a lighting system 3 which irradiates the spatial modulating device 2 with the light, and a lens system 4 which projects the light modulated by the spatial modulating device 2 on a screen are integrally assembled as an optical block 5, which is supported by a swivel shaft 8 in parallel to the optical axis 7 of the projection light 6 from the optical block 5. The optical block 5 gravitationally rotate around the swivel shaft 8, but the position relation between the spatial modulating device 2 and lens system 3 does not change even after the rotation. Therefore, even if the base 21 slants horizontally (in the right-left direction), the optical block 5 automatically becomes horizontal and can project an image of high picture quality always horizontally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a projector for projecting an image on a screen.

[0002]

2. Description of the Related Art When an image is projected on a screen by installing a projector on a table, if the table is tilted around the optical axis of the projection light emitted from the projector, that is, left and right, the image is projected on the screen. The image also tilts. Therefore, a mechanism is provided in the housing or chassis of the projector that can adjust the left and right inclination by adjusting the length of the left and right foot portions in contact with the table.

[0003]

However, each time the environment in which the projector is installed is changed, the tilt of the table changes. Therefore, the tilt must be manually adjusted each time.
It is troublesome work. In addition, since the mechanism for adjusting the tilt is provided at the bottom of the projector, the operation is troublesome and troublesome in that respect.

On the other hand, in Japanese Patent Application Laid-Open No. Hei 9-318923, a spatial modulation element for modulating light or an optical block in which a dichroic mirror for decomposing and synthesizing light is integrated with a spatial light modulating element is used. There is disclosed a projector equipped with a device which is rotatably held around an optical axis and which automatically corrects by detecting a horizontal inclination of an optical block with a sensor. With this projector, since the left and right inclinations are automatically corrected, there is no need for troublesome work. However, since a sensor for detecting the horizontal inclination of the spatial modulation element or the optical block and an actuator such as a motor for driving the spatial modulation element or the optical block in accordance with the output of the sensor are required, the structure is complicated and expensive. It is.

Accordingly, an object of the present invention is to provide a low-cost projector having a function of automatically correcting left and right inclinations.

[0006]

In order to adjust the inclination of the optical block in the horizontal direction without using a sensor and an actuator, a restoring force when the center of gravity is shifted from the axis due to the inclination can be used. However, in the system disclosed above, if the optical axis of the optical block and the projection optical system, that is, the optical axis of the projection lens or lens system is not rotated while maintaining the same state, the central axis light is shifted, so the screen The image projected on the
The aberration is hardly corrected and the image quality is degraded. Therefore, it is necessary to make the optical axis of the optical block coincide with the axis on which the optical block rotates. On the other hand, since the optical elements constituting the optical block are almost symmetrical with respect to the optical axis, it is unnatural and impossible to separate the center of gravity from the optical axis, and it is necessary to provide an unnecessary weight. Therefore, expensive systems such as sensors and actuators must be used.

Therefore, in the present invention, a spatial modulation device for modulating light with a video signal, an illumination system for irradiating the spatial modulation device with light, and a lens system for projecting the light modulated by the spatial modulation device onto a screen And a mechanism that integrates the spatial modulation device, the illumination system, and the lens system as an optical block, and further supports the projector so as to be pivotable about an axis parallel to an optical axis of projection light emitted from the optical block. A chassis (housing) for supporting the optical block from a stand or the like via the supporting mechanism is provided. By integrating the optical system including the lens system as an optical block, the positional relationship between the spatial modulation device and the lens system does not change. Therefore, even if the optical block is turned around the axis shifted from the optical axis, no image is lost or the aberration performance is not deteriorated. Therefore, with the projector of the present invention, the optical axis of the optical block can be separated from the axis, and the center of gravity of the optical block that will be located substantially along the optical axis can be separated from the axis. Become. Therefore, the horizontal or horizontal tilt of the optical block can be automatically corrected by the restoring force of the center of gravity.

Therefore, in the projector of the present invention, the center of gravity and the axis of the optical block can be separated from each other by the supporting mechanism, and further, when the optical block is inclined right and left by positioning the axis above the center of gravity. In addition, the optical block can be kept horizontal by a restoring force for returning the center of gravity to the vertical line of the axis. For this reason, the projector of the present invention can always hold the left and right directions horizontally without using complicated and expensive systems such as sensors and actuators, and can eliminate the user from the troublesome work of adjusting the inclination in the horizontal direction. Can be opened.

As the supporting mechanism, a turning shaft that is arranged along the axis and can support the optical block in a suspended state can be adopted. Alternatively, an arc-shaped rail centering on the axis may be provided as a supporting mechanism, and the optical block may move on the rail. When the arc-shaped rail is used, the projector can be made compact because the axis does not have to be provided on the chassis or in the housing.

When the restoring force of the center of gravity is used, it is desirable to provide a damper for relaxing the movement of the optical block in order to prevent the optical block from vibrating due to swing back. Further, as a supporting mechanism, a damper arranged symmetrically with respect to the axis and connected by a flow path through which the working fluid flows can be used, and the optical block can be gradually returned to a horizontal state.

[0011]

FIG. 1 shows the outline of a projector according to the present invention. The projector 1 includes a spatial modulation device 2 that modulates light with a video signal, an illumination system 3 that irradiates the spatial modulation device 2 with light, and a lens system 4 that projects light modulated by the spatial modulation device 2 onto a screen. The spatial modulation device 2, the illumination system 3, and the lens system 4 are integrally assembled as an optical block 5. Further, a turning axis 8 is provided inside the housing 9 in parallel with the optical axis 7 of the projection light 6 emitted from the optical block 5.
The optical block 5 is suspended from the pivot 8. Therefore, the optical block 5 is attached to the housing 9 via the mechanism 19 that supports the turning shaft 8. When the projector 1 is placed on a table 21 such as a desk by the chassis 10 that forms the lower part of the housing 9, the optical block 5 is optically mounted. The block 5 is set on the table 21.

The projector 1 is connected to a table 21 such as a desk.
When the optical block 5 is set on the screen 22, the vertical inclination of the housing 9 can be controlled by the feet 10a of the chassis 10 so that the vertical inclination of the optical block 5 can be controlled. 5 can project an image. And, since the optical block 5 is designed to rotate around the pivot 8 by its own weight,
The optical block 5 is automatically leveled even if the table 21 is tilted in the horizontal direction (horizontal direction), and an always horizontal image that is not tilted left and right can be projected on the screen 22.

FIG. 2 shows the projector 1 as viewed from the front. The center of gravity 11 of the optical block 5 is located substantially at the center of the optical block 5, and the turning shaft 8 is disposed above the vertical line 15. Therefore, when the table 21 is tilted left and right, the housing 9 tilts along the table 21, but the optical block 5 turns so that the center of gravity 11 is on the vertical line 15 of the turning axis 8. For this reason,
The horizontal tilt of the optical block 5 is automatically corrected,
The optical block 5 is always horizontal. The optical block 5 is also connected to the housing 9 via a damper 12. Accordingly, the damper 12 is adapted to apply a resistance to the optical block 5 in a direction orthogonal to the rotation axis 8. In addition, it resists the movement. For this reason, the center of gravity 11 of the optical block 5
Can be prevented from moving over the vertical line 15, and when the housing 9 is inclined,
Can be prevented from becoming unstable by moving like a pendulum.

Illumination system 3 included in optical block 5
Includes, for example, a white light source, and a color filter that separates the light from the white light source and supplies the light to the spatial light modulator 2. Further, an illumination system using an LED or the like that emits light of a plurality of colors as a light source may be used. An illumination system that separates and combines colors using a dichroic mirror or a dichroic prism may be used, as long as the system can irradiate the spatial modulation device 2 with appropriate light at appropriate timing.

The spatial modulation device 2 is also called a light valve or the like, and a liquid crystal panel is widely used at present. In addition, micro-electro-mechanical systems such as digital mirror devices (MEM
An image device using S) has also been developed, and any device having a function of switching light supplied from the illumination system 3 at appropriate timing may be used. Systems that separate and combine colors using a dichroic mirror and the like include systems that combine light modulated by the spatial modulation device 2.

The lens system 4 projects the light modulated by the spatial modulation device 2 onto a screen. The lens system 4 includes a plurality of lenses. When the optical path is converted in the lens system, a mirror or a prism is used. Other optical elements are also included. In the case of the lens system 4 having a zoom function, the lens moves for zooming, and an actuator such as a motor for that purpose is also included.

The optical block 5 of the projector 1 of this embodiment
The illumination system 3, the spatial modulation device 2, and the lens system 4 are fixed such that their positions do not change within the optical block 5.
Therefore, even if the optical block 5 turns around the turning axis 8, the positional relationship among the illumination system 3, the spatial modulation device 2, and the lens system 4 does not change. For this reason, the movement of the optical block 5 does not affect the optical performance of the projector 1, and an image with the best image quality can always be displayed on the screen 22.

The illumination system 3, the spatial modulation device 2, and the lens system 4 are required to have the same image quality at the top, bottom, left and right of the screen 22, and have uniform performance around the optical axis 7. Are provided. Therefore, the optical block 5 is arranged symmetrically with respect to the optical axis 7 of the projection light 6 except for the optical path inside which is not linear or the influence of elements other than optical elements such as a motor. There is a high possibility that the axis 7 coincides with or is near. Therefore, in the projector 1 of this example, since the turning shaft 8 is provided above the optical block 5, the turning shaft 8 does not coincide with the center of gravity 11, and the housing 9 is inclined and the center of gravity 11 is If it deviates from the vertical 15, a force acts to return the center of gravity 11 to the vertical 15. Therefore, the optical block 5 can always be kept horizontal without using a sensor for detecting a tilt in the horizontal direction or an actuator such as a motor for driving the optical block. Therefore, with the projector 1 of the present example, the user does not need to adjust the horizontal tilt, and can project an image on the screen 22 without worrying about the horizontal tilt.

Further, when the center of gravity 11 of the optical block 5 is located on the vertical line of the pivot 8, that is, below the vertical line, an image without tilting left and right is projected from the optical block 5 onto the screen. There is a need. For this,
The right and left balance is achieved by fixing the turning shaft 8 away from the center of the shape of the optical block 5. Further, the arrangement of the optical block 5 may be designed to balance the left and right, and a weight may be used to finely adjust the balance between the left and right. Alternatively, the direction of the image itself output to the spatial modulation device 2 may be controlled to display an image without inclination.

FIG. 3 shows an example of a different projector according to the present invention, and FIG. 4 shows a state viewed from the front. The projector 31 has a mechanism 19 for supporting the optical block 5.
A curved rail 32 is adopted, and rollers or wheels 33 are provided on the optical block 5 so that the optical block 5 slides along the rail 32 along the rail 32. Of course, as long as the rail 32 has a small coefficient of friction, the rail 32 may directly support the optical block 5. Alternatively, the rail 32 may be arranged above the optical block 5 so that the optical block 5 is suspended from the rail. Also in the projector 31 of this example, the damper 12 is arranged to prevent the optical block 5 from pendulum movement.

The rail 32 has an arc shape centered on an imaginary turning axis 35 located above the optical block 5, and the optical block 5 located below the turning axis 35.
The center of gravity 11 is turned around the turning axis 35. Therefore, similarly to the projector 1 described above,
Even if the housing 9 is tilted in the horizontal direction, the tilt of the optical block 5 in the horizontal direction is automatically corrected, and an image without left and right tilts is always projected on the screen. In the projector 31 of the present embodiment, since the rail 32 is used to support the optical block 5, the pivot 35 is virtual, and is designed so that the pivot 35 fits in the housing 9. No need. Therefore, the housing 9
Can be made compact, and the projector 1 which is small and does not require horizontal adjustment can be provided.

The center of gravity 11 of the optical block is
In the same manner as in the above-described example, the arrangement of the optical block 5 is changed, the weight is used, or the image is output to the spatial modulation device 2 so that an image without inclination is projected when the image is positioned on the vertical line 5. It is necessary to control the orientation of the image itself. In addition, there is a method in which the size of the wheel 33 is changed between left and right to make the optical block 5 horizontal.

FIG. 5 shows still another example of the projector of the present invention, and FIG. 6 shows a state as viewed from the front.
The projector 51 includes hydraulic cylinders 52 symmetrically arranged on both sides of a virtual turning shaft 55 as a mechanism 19 for supporting the optical block 5. ing. These hydraulic cylinders 52 are arranged so as to suspend the optical block 5 with respect to the housing 9, and an intermediate position of the hydraulic cylinder 52 becomes a virtual pivot 55, and the center of gravity 11 of the optical block 5 is It is located below.

The hydraulic cylinder 52 has a function of operating as a damper using oil as a working fluid. Therefore, as shown in FIG. 7, when the optical block 5 is tilted left and right, the center of gravity 11 of the optical block 5 is
5 causes oil to flow through the pipe 53
Through the cylinders 52 and each cylinder 52a and 52b is displaced an equal distance. At this time, if the diameter of the pipe 53 or the diameter of the orifice provided in the middle of the pipe is selected so as to have an appropriate resistance to the oil flow, the movement of the cylinders 52a and 52b becomes gentle, and The pendulum movement of the optical block 5 can be prevented as in each projector. Also in the projector 51 of the present example, when the optical block 5 is tilted, the optical block 5 moves so that the center of gravity 11 is located below the vertical line 15 of the turning shaft 55, and becomes horizontal.

Also, as in the previous example, the center of gravity 1 of the optical block 5 is
When 1 is located on the vertical line of the turning shaft 55, the arrangement of the optical block 5 is changed, a weight is used, the direction of the image itself output to the spatial modulation device 2 is controlled, or the cylinder 52a and By changing the thickness of 52b, the balance between left and right is achieved, so that an image without inclination is projected. Therefore, the horizontal tilt of the optical block 5 can be automatically corrected by the weight of the optical block 5 without using a sensor or an actuator, and a projector capable of automatically correcting the tilt of an image can be provided at low cost.

[0026]

As described above, in the projector of the present invention, the illumination system, the spatial modulation device and the lens system are integrated as an optical block, and the projector can be turned horizontally above the optical block as a turning axis. Like that. Therefore, even if the optical block is turned, the image is not lost or the aberration performance is not degraded, and a high-quality image can always be projected on the screen. At this time, even if the housing for housing the optical block or the supporting chassis is tilted on the table, the optical block is turned by its own weight and becomes horizontal, so that it is possible to project an image without tilting left and right. For this reason, in the projector of the present invention, a sensor or an actuator for controlling the horizontal direction of the optical block is not required, and a projector having a function of automatically adjusting left and right inclination can be provided at low cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a projector according to an embodiment of the present invention.

FIG. 2 is a diagram showing an outline of the projector shown in FIG. 1 as viewed from the front.

FIG. 3 is a diagram showing a schematic configuration of a different projector according to the embodiment of the present invention.

4 is a diagram showing an outline of the projector shown in FIG. 3 as viewed from the front.

FIG. 5 is a diagram showing a schematic configuration of still another projector according to the embodiment of the present invention.

FIG. 6 is a diagram showing an outline of the projector shown in FIG. 5 as viewed from the front.

FIG. 7 is an enlarged view illustrating a configuration of a cylinder of the projector shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 31, 51 Projector 2 Spatial modulation device 3 Illumination system 4 Lens system 5 Optical block 6 Projection light 7 Optical axis 8, 35, 55 Rotating axis 9 Housing 10 Chassis 11 Center of gravity of optical block 19 Mechanism for supporting optical block 21 units 22 screen 32 rail 52 cylinder

Claims (6)

[Claims] 1. A projector comprising: a spatial modulation device for modulating light with a video signal; an illumination system for irradiating the spatial modulation device with light; and a lens system for projecting the light modulated by the spatial modulation device onto a screen. Wherein the spatial modulation device, the illumination system, and the lens system are integrated as an optical block, and further, are supported so as to be pivotable about an axis parallel to an optical axis of projection light emitted from the optical block. A projector comprising: a mechanism; and a chassis that supports the optical block via the supporting mechanism. 2. The projector according to claim 1, wherein the supporting mechanism supports the optical block such that the axis is located above a center of gravity of the optical block. 3. The projector according to claim 2, wherein the supporting mechanism includes a turning shaft arranged along the axis and capable of supporting the optical block in a suspended state. 4. The projector according to claim 2, wherein the supporting mechanism includes an arc-shaped rail centered on the axis, and the optical block moves on the rail. 5. The projector according to claim 3 or 4, further comprising a damper for reducing a movement of the optical block. 6. The projector according to claim 2, wherein the supporting mechanism includes a damper disposed symmetrically with respect to the axis and connected by a flow path through which a working fluid flows.