JP3832315B2 - projector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a projector.
[0002]
[Prior art]
Conventionally, there is a projector as shown in FIG. 6 using a DMD (micromirror device) element.
In the figure, light emitted from a light source 1 is projected onto a light transmission diffusion screen 7 via a parabolic mirror 2 ′, a convex lens 3, a color wheel 4, a convex lens 3 ′, a DMD element 5, and a projection lens 6. .
[0003]
The parabolic mirror 2 ′ converts the light from the light source 1 into parallel light, and the convex lens 3 condenses the light from the parabolic mirror 2 ′. The color wheel 4 temporally decomposes the white light from the light source 1 into the three primary colors of light, red, blue, and green. The convex lens 3 ′ collimates the light from the color wheel 4. The light reflected by the DMD element 5 is projected as a display image on the light transmission diffusion screen 7 through the projection lens 6. The observer 20 can see an image through the light transmission diffusion screen 7.
[0004]
FIG. 7 shows the main components of the DMD element 5.
The DMD element 5 is provided on a base substrate 11 having an electrostatic force generator 10 with a mirror 8 supported by a support 9. Each of the mirrors 8 is very small, and each mirror 8 corresponds to each display pixel displayed on the light transmission diffusion screen 7.
The DMD element 5 can control the color of the display image by reflecting the light temporally decomposed into red, blue and green by the color wheel 4 toward the light transmission diffusion type screen 7 by changing the mirror 8. it can. Further, when the DMD element 5 reflects the light from the color hole 4 toward the light transmissive diffusion type screen 7, the DMD element 5 tilts the mirror 8 to change the time for reflecting the light toward the light transmissive diffusion type screen 7. The brightness of the display pixel can be controlled.
[0005]
FIG. 8 shows an optical path of light when the mirror 8 of the DMD element 5 is tilted.
FIG. 8A shows an optical path of light when the light reflected by the DMD element 5 irradiates the light transmission diffusion type screen 7.
Incident light A from the light source 1 is incident on the mirror 8 tilted upward by the electrostatic force from the electrostatic force generating unit 10, is reflected as reflected light B, and passes through the projection lens 6 to transmit the light transmission diffusion screen 7. Projected on. At this time, the DMD element 5 is turned on.
[0006]
FIG. 8B shows an optical path of light when the light reflected by the DMD element 5 is not irradiated on the light transmission diffusion screen 7.
Incident light A from the light source 1 is incident on the mirror 8 tilted to the right by the electrostatic force from the electrostatic force generator 10 and reflected as reflected light C to a place other than the projection lens 6. The state of the DMD element 5 at this time is the DMD element 5 turned off.
[0007]
[Problems to be solved by the invention]
However, in such a conventional projector, since there is no monitoring means for confirming the display contents in advance, in order to confirm the contents, the light transmission diffusion type screen 7 is actually installed and the light transmission diffusion is performed. It can only be displayed on the mold screen 7. For this reason, it is difficult to confirm the display contents when it is impossible to confirm the contents by installing the light transmission diffusion screen 7 due to space or the like. In addition, by incorporating a small liquid crystal display device as a monitor screen in the projector, the above-mentioned problems can be solved, but the cost becomes high.
[0008]
The reflected light when the DMD element 5 is in the off state is converted into heat energy by being absorbed by a black matte light absorbing sheet or the like installed in the projector. However, in the processing of the reflected light, the light that could not be completely converted into thermal energy remains in the projector as stray light, which may affect other light and cause the quality of the display image on the light transmissive diffusion type screen 7 to deteriorate. It was.
Therefore, in view of such a problem, an object of the present invention is to provide a projector having a monitor screen at low cost without using a liquid crystal display device dedicated to the monitor.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, a DMD element that reflects irradiated light by a mirror corresponding to a pixel, a DMD element control unit that controls the DMD element, and light that is reflected when the DMD element is turned on as an image in the projector having a first optical means for projecting the first display unit, a second optical means for projecting the light DMD element is reflected in the off as an image, the light reflected when the off And second display means for displaying the image as an image.
[0010]
According to the second aspect of the present invention, an optical isolator is provided in the optical path of light when the DMD element is off.
[0011]
According to a third aspect of the present invention, the optical isolator section includes a polarizing plate that changes the polarization state of light and a ½ wavelength plate that shifts the phase of light by ½ wavelength.
[0012]
According to a fourth aspect of the present invention, the light incident side surface of the second display means is surrounded by a light absorption layer, and the light incident portion where the light of the light absorption layer is incident has a pinhole shape.
[0013]
According to the fifth aspect of the present invention, the DMD element, the DMD element control unit, the first optical means, the second optical means, and the second display means are mounted on the vehicle as a unit, and light when the DMD element is on is used as an image. The first display means for displaying is provided so that it can be taken in and out from a storage unit attached to the ceiling of the vehicle.
[0014]
The invention described in claim 6 is provided with an optical sensor for measuring the illuminance of light in the vehicle, and a traveling state measuring means for determining the traveling state of the vehicle, according to the illuminance of the light in the vehicle and the traveling state of the vehicle. The image displayed on the first display means can be controlled.
[0015]
【The invention's effect】
According to the first aspect of the present invention, the image displayed on the second display means is a positive / negative inverted image with respect to the image displayed on the first display means. It is enough to check the outline of the image, and the monitor screen can be configured by adding a simple optical system, and the display content can be checked on the monitor screen without installing the first display means. Can do.
[0016]
According to the invention described in claim 2, since the light reflected in the optical path of the light to the second display means and the second display means is absorbed by the optical isolator, the reflected light is turned on by the DMD element. At this time, it is not superimposed on the reflected light from the DMD element, and the quality of the display image of the first display means is improved.
[0017]
According to invention of Claim 3, an optical isolator part can be comprised cheaply by making an optical isolator part into a polarizing plate and a half-wave plate.
[0018]
According to the fourth aspect of the present invention, light incident on the second display means does not leak out to places other than the second display means, and is superimposed on the reflected light from the DMD element when the DMD element is on. Therefore, the quality of the display image of the first display means is improved.
[0019]
According to the fifth aspect of the present invention, the image can be viewed using the projector in the vehicle, and the first display means can be accommodated. Therefore, the first display means is accommodated when not used. It does not get in the way.
[0020]
According to the sixth aspect of the present invention, since the image displayed on the first display means can be controlled according to the brightness in the vehicle and the running state of the vehicle, the display image is easy to see and depends on the running state of the vehicle. The displayed image can be controlled.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the invention will be described.
FIG. 1 illustrates an embodiment of the present invention.
The projector 21 is configured as a unit, and the light emitted from the projector 21 is displayed on the light transmission diffusion screen 7.
Inside the projector 21, the light from the light source 1 is reflected by the spheroid mirror 2 and irradiated on the DMD element 5 via the color wheel 4 and the convex lens 3 ′. The light applied to the DMD element 5 is deflected by the DMD element 5, and the light when the DMD element 5 is turned on is projected onto the light transmission diffusion type screen 7 through the projection lens 6, and the observer 20 transmits the light through the light transmission diffusion. The image displayed on the mold screen 7 can be seen. Further, when the DMD element 5 is in the off state, the light passes through the optical isolator 18, is reflected by the plane mirror 17, is projected onto the monitor light transmission diffusion screen 7 ′ through the projection lens 6 ′, and is observed on the monitor screen The person 25 can see the monitor image displayed on the light transmission diffusion screen 7 ′.
[0022]
The light source 1 is placed at the first focal point of the spheroid mirror 2, and the light from the light source 1 is condensed at the second focal point. The color wheel 4 is placed at the second focal point of the spheroid mirror 2 and rotates to temporally resolve the light from the light source 1 into the three primary colors of red, blue and green. The convex lens 3 ′ collimates the light from the color wheel 4.
[0023]
The DMD element 5 is used to form an image from the light temporally and separated into the three primary colors of light by the color wheel 4, and light incident through the convex lens 3 ′ is in a state in which the DMD element 5 is on. In this case, the light is projected onto the light transmission diffusion screen 7 through the projection lens 6.
The optical isolator 18 is installed in the optical path of light when the DMD element 5 is off, and the light when the DMD element 5 is off passes through the optical isolator 18 and is a light transmission diffusion type as a monitor screen. It is projected on the screen 7 '.
[0024]
The optical isolator section 18 is composed of a polarizing plate that changes the polarization state of light and a ½ wavelength plate that shifts the phase of the light by ½ wavelength, and allows light to pass in only one direction. The light incident on 18 is allowed to pass through, and the light incident on the optical isolator 18 from the plane mirror 17 is absorbed. The optical isolator section 18 is for reflecting light by the plane mirror 17, the projection lens 6 ′, the light transmission diffusion type screen 7 ′, etc., and not overlapping the light displayed on the light transmission diffusion type screen 7. . The light incident on the optical isolator 18 is reflected by the plane mirror 17 and projected onto the light transmission diffusion screen 7 ′ via the projection lens 6 ′.
[0025]
The light incident side of the light transmission diffusion screen 7 ′ is surrounded by the light absorption layer 16, and the light enters from the pinhole portion 15 opened in the light absorption layer 16.
The light absorbing layer 16 absorbs the light reflected by the light transmissive diffusion type screen 7 ′ and makes light incident on the light transmissive diffusion type screen 7 ′ from the pinhole portion 15, whereby the light transmissive diffusion type screen 7 ′. This prevents the light reflected by the light from being present as stray light inside the projector and affecting other light.
[0026]
FIG. 2 shows an optical path of light when the mirror 8 of the DMD element 5 is tilted.
FIG. 2A shows an optical path of light when the DMD element 5 in which the light reflected by the DMD element 5 irradiates the light transmission diffusion screen 7 is on.
Incident light A from the light source 1 is incident on the mirror 8 tilted upward by the electrostatic force from the electrostatic force generating unit 10, is reflected as reflected light B, and passes through the projection lens 6 to transmit the light transmission diffusion screen 7. Projected on.
[0027]
FIG. 2B shows an optical path of light when the DMD element 5 is in an off state where the light reflected by the DMD element 5 is not irradiated on the light transmission diffusion screen 7.
Incident light A from the light source 1 is incident on the mirror 8 tilted to the right by the electrostatic force from the electrostatic force generating unit 10 and reflected as reflected light C to the optical isolator unit 18.
[0028]
FIG. 3 shows a control configuration of the DMD element 5.
The DMD element 5 is connected to the DMD element control unit 41, and display data displayed on the light transmission diffusion type screen 7 is input to the DMD element control unit 41 via the drawing circuit 42. In the DMD element 5, the tilt of the mirror 8 is controlled by the DMD element control unit 41, and the mirror 8 is changed to form an image from the light from the color wheel 4.
[0029]
An example in which the projector of the present invention is mounted on a vehicle is shown in FIG.
The projector 21 is attached to the ceiling in the center of the front seat of the vehicle 24, and the light transmission diffusion screen 7 including the storage portion 22 is attached to the ceiling slightly behind the vehicle from there. The light transmission diffusion type screen 7 is taken out from the storage part 22, and is attached to a place where it can be seen from the rear seats in an unfolded state.
FIG. 4B shows the configuration of the light transmission diffusion screen 7.
The light transmission diffusion type screen 7 has a storage portion 22 made of a motor or the like so that it can be inserted and removed electrically, and the insertion and removal are controlled by a signal from the storage control portion 23.
[0030]
When the front seat person confirms the display contents on the light transmission diffusion screen 7 ′ which is a monitor screen, the light transmission diffusion screen 7 is stored in the storage unit 22, and the light transmission diffusion screen 7 ′ for monitoring is used. By confirming the displayed image, it is possible to confirm the display contents without being seen by the backseat.
[0031]
FIG. 5 shows a control configuration of the DMD element 5 when the projector of the present invention is mounted on a vehicle.
The DMD element 5 is connected to the DMD element control unit 41, and display data displayed on the light transmission diffusion type screen 7 is input to the DMD element control unit 41 via the drawing circuit 42. The DMD element control unit 41 receives signals from the optical sensor 44 and the parking brake sensor 45.
The DMD element control unit 41 can control the DMD element 5 with reference to a signal from the optical sensor 44 to control the luminance of the image displayed on the light transmission diffusion screen 7. Further, based on the parking brake on / off signal from the parking brake sensor 45, control is performed such as whether or not to display an image in accordance with the traveling state of the vehicle such as traveling or stopping.
[0032]
The present embodiment is configured as described above, and the light when the DMD element 5 is off should be projected onto the light transmission diffusion screen 7 by projecting it onto the light transmission diffusion screen 7 'for the monitor screen. A positive / negative inverted image of the image is displayed on the light transmission diffusion screen 7 ′. Although the image projected on the light transmission diffusion screen 7 ′ is a positive / negative inverted image, it is sufficient for confirmation, and unnecessary light reflected from the DMD element 5 that has been conventionally thermally converted in the projector is used. Thus, an image for a monitor screen can be obtained at a low cost.
[0033]
The light transmitting diffusion screen 7 ′ is surrounded by the light absorption layer 16 and the light incident on the light transmitting diffusion screen 7 ′ is reflected. Even so, the reflected light is absorbed by the light absorption layer 16. Further, by providing the optical isolator 18 in the optical path of the light when the DMD element 5 is off, the light reflected by the light transmissive diffusion screen 7 ′, the plane mirror 17, and the projection lens 6 ′ is absorbed by the optical isolator 18. . As a result, the light reflected by the light transmissive diffusion type screen 7 ′, the plane mirror 17, and the projection lens 6 ′ exists as stray light in the projector, and is superimposed on the light of the image displayed on the light transmissive diffusion type screen 7. Quality degradation can be prevented.
[0034]
By inputting signals from the optical sensor 44 and the parking brake sensor 45 to the DMD element control unit 41, the display image is displayed so as to be easy to see from the occupant according to the brightness of the interior of the vehicle, and according to the running state. The DMD element 5 is controlled so as to be turned on / off.
When the light transmission diffusion screen 7 is stored in the storage unit 22, an occupant on the front seat passenger seat sees the light transmission diffusion screen 7 ′ for the monitor screen, and is displayed on the light transmission diffusion screen 7. The content of the display image of the display data to be confirmed can be confirmed without being seen by the backseat.
[0035]
In this embodiment, the ellipsoidal mirror 2, the parabolic mirror 2 ′ and the convex lens 3 are used. However, any other one can be used as long as it has a function for condensing the light from the light source 1 at one point. The convex lens 3 ′ may be another optical system as long as it is an optical system for collimating light. Note that an integrator optical system such as a fly-eye lens for making the light intensity uniform may be added to this optical system.
The color wheel 4 is used as an element for temporally decomposing light from the light source 1 into red, green, and blue, but other elements may be used, such as the light transmission diffusion type screen 7 and the light transmission diffusion type screen 7 ′. If the projector is mounted on a vehicle that can display light as an image, it is installed at a position where the passenger in the front passenger's seat can check the monitor screen. May be.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of the present invention.
FIG. 2 is a diagram showing light reflection in a DMD element.
FIG. 3 is a diagram illustrating control of a DMD element.
FIG. 4 is a diagram showing an example in which the present invention is mounted on a vehicle.
FIG. 5 is a diagram illustrating control of a DMD element.
FIG. 6 is a conventional projector.
FIG. 7 is an enlarged view of a DMD element.
FIG. 8 is a diagram showing light reflection in a DMD element.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Light source 2 Spheroid mirror 2 'Parabolic mirror 3, 3' Convex lens 4 Color wheel 5 DMD element 6 Projection lens (1st optical means)
6 'projection lens (second optical means)
7 Light transmission diffusion screen (first display means)
7 'Light diffusing screen (second display means)
DESCRIPTION OF SYMBOLS 8 Mirror 9 Support part 10 Electrostatic force generation part 11 Base board 15 Pinhole part 16 Light absorption layer 17 Plane mirror 18 Optical isolator part 20 Viewer 21 Projector 22 Storage part 23 Storage control part 24 Vehicle 25 Monitor screen observer 41 DMD element control Unit 42 Drawing circuit 44 Optical sensor 45 Parking brake sensor (running state measuring means)
A Incident light B, C Reflected light

Claims (6)

A DMD element is reflected by the mirror corresponding to the irradiated light in a pixel, projecting a DMD element control unit for controlling the DMD element, a light the DMD element is reflected when on the first display means as an image In a projector having a first optical means for
Second optical means for projecting the reflected light as an image when the DMD element is off;
And a second display means for displaying the reflected light as an image when turned off . The projector according to claim 1, further comprising an optical isolator portion in an optical path of light to the second optical unit when the DMD element is off. The projector according to claim 2, wherein the optical isolator section includes a polarizing plate that changes light into a polarization state and a half-wave plate that shifts the phase of light by a half wavelength. 4. The light incident side surface of the second display means is surrounded by a light absorption layer, and a light incident portion on which light of the light absorption layer is incident is formed in a pinhole shape. The projector described. The DMD element, the DMD element control unit, the first optical means, the second optical means, and the second display means are mounted on a vehicle as a unit, and display light when the DMD element is on as an image. 5. The projector according to claim 1, wherein the first display means is provided so as to be able to be taken in and out from a storage portion attached to a ceiling of the vehicle. An optical sensor that measures the illuminance of light in the vehicle and a traveling state measuring unit that determines the traveling state of the vehicle are provided, and is displayed on the first display unit according to the illuminance of the light in the vehicle and the traveling state of the vehicle. 6. The projector according to claim 5, wherein an image to be controlled can be controlled.

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