JP2005208135A - Projector equipped with tilt sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector which detects tilt of a light valve in a projector cabinet with high precision without being influenced by assembly error of components in the projector. <P>SOLUTION: A chassis 2 is fixed to the interior of a projector cabinet 1. An optical cylinder 7 holding a magnifying lens 6 is fixed to the projector cabinet 1 and penetrates a side wall of the chassis 2. A lamp 8 and the light valve 5 are provided inside the chassis 2. An electronic circuit board 3 is attached to the upper surface of the chassis 2. An acceleration sensor 4 is directly attached to the light valve 5. The light valve 5 is electrically connected with the electronic circuit board 3 by wiring 9. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projector that projects an image on a screen or a wall surface, and more particularly to a projector that can correct distortion of a projected image.

  2. Description of the Related Art Conventionally, correction of image distortion that occurs when an image is projected onto a screen by tilting the projector housing in a projector has been performed (see, for example, Patent Documents 1 and 2).

  FIG. 4 is a cross-sectional view schematically showing an example of the internal structure of such a conventional projector.

  A conventional projector includes a projector housing 1 as shown in FIG. A chassis 2 is fixed inside the projector housing 1. An optical cylinder 7 holding a magnifying lens 6 is fixed to the projector housing 1 and penetrates the side wall of the chassis 2.

  Inside the chassis 2, a lamp 8 and a light bulb 5 are provided. The light valve 5 is a liquid crystal panel or DMD panel.

  An electronic circuit board 3 is attached to the upper surface of the chassis 2, and an acceleration sensor 4 is mounted on the electronic circuit board 3. The light valve 5 is electrically connected to the electronic circuit board 3 by wiring 9.

  The light bulb 5, the lamp 8, the dichroic prism, the magnifying lens 6 and the like constitute an optical unit of the projector. An image passing through the light valve 5 is projected onto a screen, a wall surface or the like by the magnifying lens 6.

In such a projector, when the projector housing 1 is tilted and an image is projected onto the screen, the tilt amount is calculated from the output result of the acceleration sensor 4 and the distortion of the image is corrected according to the tilt amount.
JP 2003-283963 A JP 2003-295310 A

  When it is determined from the output result of the acceleration sensor 4 that the projector housing is substantially horizontal with respect to the floor surface, the image must be projected without distortion on a screen that is stretched substantially perpendicular to the floor surface. .

  However, in the projector as shown in FIG. 4, since the acceleration sensor 4 is attached to the electronic circuit board 3, the acceleration sensor 4 monitors the level of the electronic circuit board 3 and the inclination of the light valve 5. Is not directly monitored. For this reason, if there is an assembly error of the electronic circuit board 3 with respect to the chassis 2 and an assembly error of the light valve 5 with respect to the chassis 2, the output result of the acceleration sensor 4 is horizontal with respect to the floor surface. Even if it determines, a projection image may be distorted.

  An object of the present invention is to provide a projector having a structure in which the inclination of a light valve in a projector housing is detected with high accuracy without receiving an assembly error of components in the projector in view of the above-described problems of the prior art.

  In order to achieve the above object, according to the present invention, in a projector including a tilt sensor and a light valve for forming an image, the tilt sensor is attached to the light valve.

  In the configuration as described above, since the tilt sensor is directly attached to the light valve, the light when the projector housing is tilted with respect to the installation surface without being affected by the light valve assembly error in the projector. The inclination angle of the valve is obtained directly from the output of the inclination sensor. As a result, when it is determined from the output result of the tilt sensor that it is horizontal with respect to the installation surface, the projected image is projected without distortion.

  The projector includes a housing, a chassis fixed inside the housing, a lamp disposed in the chassis, and an optical system that magnifies and projects an image of the light bulb illuminated by the lamp. The light valve is disposed in the chassis.

  The projector preferably has a mechanism for tilting the light valve so that the image forming surface of the light valve is maintained substantially perpendicular to the installation surface of the projector when the projector is tilted.

  The tilt sensor is preferably an acceleration sensor.

  It is preferable that the acceleration sensor detects two acceleration components in the vertical direction and the horizontal direction with respect to the image projection surface.

  A liquid crystal panel or DMD panel is preferably used as the light valve.

  According to the present invention, in a projector including a tilt sensor and a light valve that forms an image, the tilt sensor is directly attached to the light valve, so that the projector housing can be mounted without receiving assembly errors of components in the projector. The inclination of the light valve can be detected with high accuracy. For this reason, when it determines with it being horizontal with respect to an installation surface from the output result of an inclination sensor, a projection image without distortion can be projected.

  Next, embodiments of the present invention will be described with reference to the drawings. Below, a different point from the prior art shown in FIG. 4 is demonstrated.

  FIG. 1 is a sectional view schematically showing an example of the internal structure of a projector according to an embodiment of the present invention. FIG. 2 is a block diagram showing a control configuration of the projector shown in FIG.

  As shown in these drawings, the projector 13 according to this embodiment includes a light valve 5, an angle detection unit 10, a distortion correction unit 11, and an image input unit 12.

  The image input unit 12 inputs an image output from an image output device such as a DVD player, a video deck, or a personal computer.

  The acceleration sensor 4 is directly attached to the light valve 5 (FIG. 1), and outputs a voltage corresponding to the acceleration component. The angle detection unit 10 detects the installation angle of the projector 13 based on the voltage value output from the acceleration sensor 4. The angle detection means for detecting the installation angle of the projector 13 is not limited to the acceleration sensor 4 and may be an angle sensor using a pendulum.

  The distortion correction unit 11 is configured by a computer including a CPU and a memory, and performs trapezoidal distortion correction on the image input from the image input unit 12. At this time, the correction amount is adjusted according to the angle information input from the angle detection unit 10.

  The light valve 5 uses a liquid crystal panel or DMD panel, and in the case of a liquid crystal panel, either a reflection type or a transmission type panel may be used. An image corrected by the distortion correction unit 11 is formed on the light valve 5. The image formed on the light bulb 5 is illuminated by the light emitted from the lamp 8 and enlarged and projected onto a screen or wall (not shown) that is an image projection surface by the magnifying lens 6 configured in the optical cylinder 7.

  In this embodiment, as shown in FIG. 1, the acceleration sensor 4 is directly attached to the light valve 5, so that the assembly error of the electronic circuit board 3 to the chassis 2 and the light to the chassis 2 are The tilt angle of the light valve 5 when the projector housing 1 is tilted with respect to the installation surface such as a desk can be directly obtained from the output of the acceleration sensor 4 without being affected by the assembly error of the bulb 5. As a result, when it is determined from the output result of the acceleration sensor 4 that it is horizontal with respect to the installation surface, the projected image is projected without distortion.

  Further, the acceleration sensor 4 is orthogonal to the image projection plane when the acceleration sensor 4 detects an acceleration component in the vertical direction with respect to the image projection plane and can also detect an acceleration component in the horizontal direction with respect to the image projection plane. The error is eliminated even with respect to the deviation of the rotation direction of the projected image around the axis to be rotated.

  Next, another embodiment of the projector of the present invention will be described.

  FIG. 3 is a sectional view schematically showing another embodiment of the projector of the present invention.

  The form shown in FIG. 3 is a projector in which the light valve 5 of the form shown in FIG. 1 is replaced with a light valve 51 with a tilting mechanism. The acceleration sensor 4 is directly attached to the light valve 51 with the tilt mechanism. As shown in FIG. 3, the light valve 51 with the tilt mechanism has a panel surface (image forming surface) with respect to the installation surface 14 when the surface side portion on which the magnifying lens 6 is disposed is lifted above the installation surface 14. Is tilted to maintain a substantially vertical state. As a result, the projected image can be projected without distortion.

  In such a configuration, the projection image without distortion is obtained by keeping the output value of the acceleration sensor 4 constant when the surface side portion on which the magnifying lens 6 is disposed is lifted above the installation surface 14. The control process can be simplified.

1 is a cross-sectional view schematically showing an example of an internal structure of a projector according to an embodiment of the invention. It is a block diagram which shows the structure part which performs image distortion control of the projector shown in FIG. It is sectional drawing which showed the state which carried out the tilting projection in another embodiment of the projector of this invention. It is sectional drawing which showed typically an example of the internal structure of the conventional projector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Projector housing | casing 2 Chassis 3 Electronic circuit board 4 Acceleration sensor 5 Light valve 6 Magnifying lens 7 Optical cylinder 8 Lamp 9 Wiring 10 Angle detection part 11 Distortion correction part 12 Image input part 13 Projector 51 Light valve with tilt mechanism

Claims (6)

In a projector equipped with a tilt sensor and a light valve,
The projector, wherein the tilt sensor is attached to the light valve. A housing,
A chassis fixed inside the housing;
A lamp disposed in the chassis;
An optical system that magnifies and projects an image of the light bulb illuminated by the lamp,
The projector according to claim 1, wherein the light valve is disposed in the chassis.   3. The projector according to claim 1, further comprising a mechanism that tilts the light valve so that an image forming surface of the light valve is substantially perpendicular to an installation surface of the projector when the projector is tilted.   The projector according to claim 1, wherein the tilt sensor is an acceleration sensor.   The projector according to claim 4, wherein the acceleration sensor detects two acceleration components in a vertical direction and a horizontal direction with respect to the image projection surface.   The projector according to claim 1, wherein a liquid crystal panel or a DMD panel is used as the light valve.

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