JP2009003107A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of easily projecting images, having different aspect ratios by means of a smaller number of components than the conventional types. <P>SOLUTION: The projector 1 is provided with a light source 3 for emitting light to display a projection image, a light tunnel 6, and a DMD 10 modulating light emitted from the outgoing port of the light tunnel 6, to form the projection image. The light tunnel 6 is provided with two opening parts (a first opening part 21 and a second opening part 22) each of which has different aspect ratio. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a projection apparatus, and more particularly to a technique for adjusting an aspect ratio of an image projected by a projection apparatus.

  A projection apparatus (for example, a projector) using an optical modulation element applies light modulation corresponding to a video signal to light that illuminates the optical modulation element, and enlarges and projects the modulated modulated light using various lenses. is there.

  An image (video) projected by a projection device such as a projector generally has an aspect ratio of 4: 3 (horizontal length of image: vertical length of image). This is because the image signal input to the projector is a television video signal having an aspect ratio of 4: 3, and the projector is also adapted to this standard.

  However, in recent years, as the spread of televisions having an aspect ratio of 16: 9, so-called wide televisions, has increased, the demand for image display having an aspect ratio of 16: 9 has also increased in projectors. In addition, when a digital image (including video) or a movie is projected on a DVD, it is desired to project the image with an aspect ratio of 16: 9 or 2.4: 1.

Under such circumstances, it has been necessary to project images having different aspect ratios with a single projection apparatus.
Here, the aspect ratio of the projected image depends on the aspect ratio of the region where the optical modulation element is illuminated. In addition, the aspect ratio of the region where the optical modulation element is illuminated depends on the aspect ratio of the exit shape of the light tunnel that is provided upstream of the optical modulation element and adjusts the shape of light from the light source. That is, the aspect ratio of the projected image is determined by the shape of the light tunnel exit that adjusts the light shape.

Therefore, a plurality of light tunnels having different aspect ratios are provided, and a light tunnel having a desired aspect ratio can be selected from the plurality of light tunnels, thereby enabling conversion of the aspect ratio of the projected image. There are some (see, for example, Patent Document 1).
JP 2003-348496 A (published on December 5, 2003)

However, the conventional configuration requires a plurality of light tunnels and a mechanism for moving the light tunnels to the optical path, and there is a problem that a large number of components are required.
SUMMARY OF THE INVENTION An object of the present invention is to provide a projection apparatus that can easily project images having different aspect ratios with fewer constituent members than in the past.

  A projection apparatus according to a first invention includes a light source, a light tunnel, and an optical modulation element. The light source emits light for displaying a projected image. The light tunnel has an entrance through which light is incident from a light source, and an exit through which the light incident on the entrance exits and the shape of the opening determines the aspect ratio of the projected image. The mouth has a different aspect ratio. The optical modulation element modulates the light emitted from the light tunnel exit to produce a projected image.

Here, in order from the upstream of the light, a light source, a light tunnel having an entrance and an exit having different aspect ratios, and an optical modulation element are provided.
Here, the light tunnel is a cylindrical light transmission means, and has an opening as an entrance on the side where light enters from the light source. The light that has entered the light tunnel from the incident port travels while being repeatedly reflected inside the cylindrical body, and has an opening serving as an emission port on the side from which the light is emitted. Also, the aspect ratio is the ratio of the length to the length, the aspect ratio of the projected image depends on the aspect ratio of the illuminated area of the optical modulation element, and the aspect ratio of this illuminated area is that of the light tunnel. It depends on the aspect ratio of the exit.

  For example, an electrodeless lamp may be used as the light source. The light tunnel preferably uses a cylindrical glass rod having four planar mirror surfaces on the inside. In order for the entrance port and the exit port to have different aspect ratios, it is desirable that at least one of the inner mirror surfaces has a tapered shape having a uniform inclination from the entrance port to the exit port. For example, DMD can be used as the optical modulation element.

  Conventionally, as a method for converting the aspect ratio of a projected image, for example, there are the following methods. First, a plurality of rectangular parallelepiped light tunnels are used, and the aspect ratios of the openings of the cross sections of the plurality of light tunnels are different among the respective light tunnels. Then, the light tunnel having a desired aspect ratio is selected from the plurality of light tunnels and arranged in the optical path.

However, such a method requires a plurality of light tunnels and a mechanism for moving the light tunnels to the optical path, and has a problem that a large number of components are required.
Therefore, the present invention includes a light tunnel having a different aspect ratio between the entrance and the exit, between the light source and the optical modulation element.

According to such a configuration, the light incident on the entrance is made uniform by repeating reflection in the light tunnel. Therefore, it is possible to project an image without illuminance unevenness. Further, the illuminated area of the optical modulation element and the aspect ratio of the projected image depend on the shape of the light tunnel exit. For this reason, for example, by reversing the direction of the light tunnel, the entrance and the exit are interchanged, and the aspect ratio of the exit can be converted. That is, the aspect ratio of the entrance and the aspect ratio of the exit are switched, and the aspect ratio of the projected image is converted. For example, if the aspect ratios of the entrance and exit are designed to be 16: 9 and 4: 3, respectively, it is possible to easily select projection images having these two aspect ratios.
Therefore, it is possible to form projection images having two different aspect ratios by one light tunnel, and it is possible to reduce the number of constituent members as compared with the related art.

A projection apparatus according to a second invention is the projection apparatus according to the first invention, further comprising a rotation mechanism that reverses the entrance and exit of the light tunnel,
Here, a rotation mechanism for reversing the light tunnel is further provided. As a result, the light tunnel can be mechanically easily inverted. As a result, it is possible to reverse the entrance and the exit with good reproducibility. Further, by electrically controlling the rotation mechanism, it is possible to convert the projected image into a desired aspect ratio by a simple operation such as pressing an operation button.

A projection apparatus according to a third aspect of the invention is the projection apparatus according to the first or second aspect of the invention, and further includes a rotation axis that becomes the rotation center of the light tunnel.
Here, in order to invert the entrance and exit of the light tunnel, the light tunnel is rotated. And it fixes by providing a rotating shaft in the rotation center. Thereby, since the rotation center is fixed, the positioning accuracy of the light tunnel can be improved. As a result, it is possible to prevent the displacement of the illumination position with respect to the optical modulation element and the missing image.

  A projection device according to a fourth invention is the projection device according to the first to third inventions, and is formed in the light tunnel and a locking portion for positioning the entrance and exit of the light tunnel. And a locked portion.

  Here, a locking portion and a locked portion for positioning the entrance and the exit of the light tunnel are further provided. Here, the formation position of the locking portion and the locked portion may be a position where the light emitted from the light tunnel exit port illuminates the optical modulation element most efficiently in a state where they are locked to each other. desirable. Moreover, it is desirable to form so as to limit the rotation width by the rotation mechanism. As a result, the rotation width of the light tunnel is mechanically limited, and positioning of the light tunnel can be performed with a highly accurate and simple mechanism. Therefore, it is possible to prevent the displacement of the illumination position with respect to the optical modulation element and the lack of images.

  A projection apparatus according to a fifth aspect of the present invention is the projection apparatus according to any of the first to fourth aspects of the present invention, further comprising a converging unit for converging the light emitted from the light source upstream of the light tunnel, and entering the incident port. The light beam is inscribed in the shape of the smaller one of the entrance and the exit.

  Here, it further includes a converging unit for converging the light emitted from the light source before entering the light tunnel entrance. Then, the focused light, that is, the light flux, is inscribed in a shape having a smaller area between the entrance and the exit of the light tunnel. Thereby, even if the area of the entrance is changed by inverting the light tunnel, the light from the light source is efficiently incident on the entrance and the loss of light quantity can be reduced. Therefore, even when an image having any aspect ratio is projected, it is possible to project an image having a high luminous intensity.

  A projection device according to a sixth aspect of the invention is the projection device according to the first aspect of the invention, and has two sets of planar mirror surface portions facing each other on the inner surface of the light tunnel, and an interval between the facing mirror surface portions is set. An operating mechanism for adjusting is further provided.

  Here, the openings of the entrance and the exit include the end portions of four mirror surface portions provided inside the light tunnel. At least one of the mirror surface portions is variable, and further includes an operating mechanism that adjusts the distance between the opposing mirror surface portions. As a result, the aspect ratio of the exit port can be changed even with a single light tunnel. Therefore, it is possible to project an image having a desired aspect ratio with a small number of components.

  A projection apparatus according to a seventh invention includes a light source, a light tunnel, and an optical modulation element. The light source emits light for displaying a projected image. The light tunnel emits the light incident from the light source, the light incident on the incident port, the exit that determines the aspect ratio of the projected image, and the aspect ratio of the exit to the desired aspect ratio. And a variable part for changing. The optical modulation element modulates the light emitted from the light tunnel exit to produce a projected image.

  Here, the light tunnel emits the light incident from the light source, the light incident on the incident aperture, the exit aperture whose shape determines the aspect ratio of the projected image, and the desired aspect ratio of the exit aperture. And a variable unit for changing the aspect ratio.

  Thereby, the aspect ratio of the projected image is determined by the aspect ratio of the exit port, and the aspect ratio of the exit port can be changed by one light tunnel. Therefore, it is possible to project an image having a desired aspect ratio with a small number of components.

  A projection device according to an eighth invention is the projection device according to the seventh invention, wherein the inner surface of the light tunnel has two sets of opposing planar mirror surface portions, and the variable portion of the light tunnel is: At least one mirror surface portion is included among the mirror surface portions.

  Here, the variable part includes at least one mirror surface part. For example, a pair of facing mirror surface portions are fixed, and the other pair of facing mirror surface portions can be rotated with the end portion on the incident port side as a fixed end. As a result, the light tunnel can be changed to a light tunnel having a tapered inner surface having a uniform inclination from the entrance to the exit. That is, the aspect ratio of the exit port can be adjusted to a desired aspect ratio. Therefore, it is possible to project an image having a desired aspect ratio with a simple configuration without reducing the reflection efficiency of the inner surface of the light tunnel.

A projection device according to a ninth invention is the projection device according to the seventh or eighth invention, further comprising an aspect ratio setting mechanism for displacing the variable portion of the light tunnel.
Here, an aspect ratio setting mechanism for displacing the variable portion is further provided. Thereby, it becomes possible to displace the variable part mechanically easily. As a result, it is possible to change the aspect ratio of the exit port with high precision and reproducibility. Further, by electrically controlling the aspect ratio setting mechanism, it is possible to change the projected image to a desired aspect ratio by a simple operation such as pressing an operation button.

A projection apparatus according to a tenth invention is the projection apparatus according to the first to ninth inventions, further comprising a color wheel on the upstream side or the downstream side of the light tunnel.
Here, a color wheel is provided immediately upstream or downstream of the light tunnel. The color wheel has filters of the three primary colors of RGB, and the light beam rotates at a predetermined rotation speed so as to pass through the filter portions of each color in order. This also makes it possible to easily change the aspect ratio of the projected image as described above and to project a color image.

A projection apparatus according to an eleventh aspect is the projection apparatus according to any one of the first to tenth aspects, wherein the optical modulation element is a digital micromirror device.
Here, DMD is used as the optical modulation element. The DMD is constructed by integrating a large number of microscopic mirrors that can be driven in a matrix on the surface of one chip. By controlling the posture (tilt) of the mirrors and switching the reflection angle of the reflected light, Modulate. Thereby, a desired image can be projected. In particular, a desired color image can be projected by synchronizing the emission timing of the three primary colors of RGB by the color wheel and the driving timing of the reflecting mirror.

  According to the projection device of the present invention, it is possible to form projection images having different aspect ratios by one light tunnel, and it is possible to reduce the number of constituent members as compared with the conventional case.

(Embodiment 1)
A projector (projection apparatus) 1 according to an embodiment of the present invention will be described below with reference to FIGS. In the optical path from the light source 3 to the projection object (for example, a screen), the direction of the light source 3 is assumed to be upstream, and the direction of the projection object is assumed to be downstream.

[Overall configuration of projector 1]
The projector 1 according to the present embodiment includes a one-chip DLP (Digital Light Processing) (registered trademark) system using a DMD (Digital Micromirror Device) (optical modulation element) 10 configured by arranging a plurality of micromirrors on a semiconductor. As shown in FIG. 1, the projector 1 mainly includes a light source 3, a reflector 4, a condenser lens 5, a light tunnel 6, and a rotation mechanism 7 for rotating the light tunnel 6 (see FIG. 5). ), A color wheel 8, a relay lens 9, a DMD 10, and a projection lens 11.

As the light source 3, an ultra-high pressure mercury lamp having high luminous efficiency is used.
The reflector 4 is provided with a parabolic surface portion 4a covering the other side of the light source 3 on the inside in order to reflect the light from the light source 3 and collect it in one direction (downstream side in the flow of light). It has been. The paraboloid 4a, that is, the surface of the reflector 4 on the side facing the light source 3 is preferably a mirror surface having a high reflectance, particularly a mirror surface having a high reflectance for visible light. Furthermore, since the material of the reflector 4 is one of the components closest to the light source 3, considering the influence of heat from the light source 3, a material having excellent heat resistance, such as crystallized glass, etc. It is desirable to include. In the present embodiment, a crystallized glass surface in which aluminum is formed by vacuum deposition is used.

  The condenser lens 5 is provided on the downstream side of the light source 3, and both the direct light from the light source 3 and the light reflected by the reflector 4 are incident thereon. The condensing lens 5 condenses incident light toward a predetermined focal point.

  The light tunnel 6 is a cylindrical member having a first opening portion 21 and a second opening portion 22, and the light that has been collected by the condensing lens 5 is repeatedly reflected inside the light tunnel 6. The shape of light at the light exit provided on the downstream side of the light tunnel 6 (the shape of the cross section perpendicular to the traveling direction of light) is set to be uniform with the mirror surface of the DMD 10. Since it is in an imaging relationship, it plays the role of determining the aspect ratio of the projected image. The configuration of the light tunnel 6 will be described in detail later.

  As shown in FIG. 5, the rotation mechanism 7 is a mechanism provided for reversing the light tunnel 6 to change the orientation of the first opening 21 and the second opening 22. It has the part 32 and the to-be-latched part 33a * 33b. The configuration of the rotating mechanism 7 will be described in detail later together with the configuration of the light tunnel 6.

  The color wheel 8 is a color extraction member disposed immediately downstream of the light tunnel 6 and has a color filter including RGB three primary colors. The color filter is configured by combining fan-shaped filters of each color equally divided at 120 degrees for each of the three primary colors of RGB. In addition, the light incident on the color wheel 8 is rotated in a clockwise direction at a predetermined rotation speed so that the RGB three primary colors of the color filter sequentially pass through the focal portion of the light. To be separated.

  The relay lens 9 is provided on the downstream side of the color wheel 8 in order to guide the light emitted from the light source 3 to the DMD 10. The relay lens 9 condenses and guides the three colors of light that have passed through the color wheel 8 with respect to the plurality of micromirrors included in the DMD 10. As shown in FIG. 1, the relay lens 9 may be plural or singular. Moreover, you may include things other than a lens like the plane mirror 9a. However, the shape of light on the incident end side of these light guide members 9, that is, the shape of the light exit of the light tunnel 6, and the shape of light on the reflection surface of the DMD 10 described below, that is, the shape of the irradiated area of the DMD 10, are image forming relationships. It has become.

  The DMD 10 is configured by integrating a large number of drivable micromirrors (minute reflectors) in a matrix on the surface of one chip. The DMD 10 modulates the light by controlling the attitude (tilt) of the micromirror and switching the reflection angle of the reflected light. Specifically, when a micromirror of a certain pixel is in an off state, light reflected by the micromirror is not incident on the projection lens 11. On the other hand, when the micromirror is on, the reflected light from the micromirror is incident on the projection lens 11. In this manner, the color image enlarged via the projection lens 11 is projected onto the screen by switching the inclination of each micromirror so as to synchronize with the light emission timing of the RGB three primary colors by the color wheel 8 described above. be able to.

  The projection lens 11 is a lens for enlarging and projecting the light modulated in the DMD 10 on the screen, and is arranged in the traveling direction of the effective light reflected by the DMD 10.

(Configuration and location of light tunnel 6)
As shown in FIG. 1, the light tunnel 6 according to the present embodiment is mounted on the projector 1 as described above to determine the optical integrator and the aspect ratio of the projected image. And the light tunnel 6 has comprised the cylindrical shape which has the 1st opening part 21 and the 2nd opening part 22, as shown in FIG. 2 and FIG.

  The light tunnel 6 is formed by combining four glass flat plates. Therefore, this light tunnel 6 has two sets of planes 23, 25, 24, and 26 that face the inside, and the surfaces of these planes 23, 24, 25, and 26 totally reflect incident light. It is a mirror surface.

  Of the two sets of opposed planes 23, 25, 24, and 26, one set of opposed planes 24 and 26 is parallel to each other and parallel to the horizontal plane. On the other hand, the other pair of opposing flat surfaces 23 and 25 are provided with a uniform inclination so as to taper from the first opening 21 toward the second opening 22. That is, a taper shape is formed from the first opening 21 to the second opening 22. Therefore, in the present embodiment, the area of the second opening 22 is smaller than the area of the first opening 21. More specifically, the aspect ratio of the first opening 21 is 16: 9, and the aspect ratio of the second opening 22 is 4: 3. As described above, the illumination area of the DMD 10 and the aspect ratio of the projected image depend on the aspect ratio of the shape of the opening on the exit end side of the light tunnel 6, so in this state where the second opening 22 is the exit, the projected image The aspect ratio is 4: 3.

  Next, the arrangement position of the light tunnel 6 (positional relationship with other members) will be described. Here, a description will be given in a state where the second opening 22 is disposed as a light entrance (however, as will be described later, the first opening 21 and the second opening 22 are caused by the rotation of the light tunnel 6). Can be reversed). The light tunnel 6 is disposed so that the second opening 22 is positioned in the vicinity of the focal point 27 of the light (light flux) collected by the condenser lens 5. More specifically, the light tunnel 6 is provided such that the shape of the light beam (the shape of the cross section perpendicular to the traveling direction of the light beam) is inscribed in the second opening 22 (see FIG. 4). The straight line connecting the center of the first opening 21 and the center 29 of the second opening 22 is arranged so as to coincide with the straight line connecting the light source 3 and the focal point 27 of the condenser lens 5. If it does in this way, the light condensed by the condensing lens 5 will be inscribed in the opening part (2nd opening part 22 in this embodiment) with a smaller opening area among the two opening parts of the light tunnel 6. It will be incident. Therefore, the light emitted from the light source 3 enters the inside of the light tunnel 6 with high efficiency, so that the utilization efficiency of the light from the light source 3 is increased and the brightness of the projected image is improved.

[Configuration of Rotating Mechanism 7]
Next, the rotation mechanism 7 for inverting the first opening 21 and the second opening 22 of the light tunnel 6 will be described with reference to FIG. The rotating mechanism 7 includes a rotating shaft 31, a locking portion 32, and two locked portions 33a and 33b.

  The rotating shaft 31 is a rod-shaped member, and one end portion 31a is fixed to the center of one surface 30 outside the light tunnel 6 (the surface outside the glass flat plate having the flat surface 24). It is provided vertically with respect to it. The other end 31b is rotatably supported by a casing (not shown) of the projector 1.

  The locking part 32 is provided so as to protrude from the outer surface 30 of the light tunnel 6 in the same direction as the rotary shaft 31 and has a cylindrical shape. The locked portions 33a and 33b are provided so that the locking portions 32 are locked, and have semi-cylindrical recess portions 34a and 34b so that the cylindrical locking portions 32 are fitted. Yes.

  Here, the formation position of the rotating shaft 31, the locking part 32, and the locked parts 33a and 33b will be described. First, a straight line connecting the center 28 of the first opening 21 and the center 29 of the second opening 22 in a state where the locking portion 32 is in contact with and locked to the locked portion 33a is a straight line A. Next, a straight line connecting the center 28 of the first opening 21 and the center 29 of the second opening 22 in a state where the locking portion 32 is in contact with and locked to the locked portion 33b is a straight line B. The rotating shaft 31, the locking portion 32, and the locked portions 33a and 33b are positioned so that the straight line A and the straight line B in the respective states where the light tunnel 6 is inverted as described above spatially coincide with each other. To form. That is, even if the first opening 21 and the second opening 22 are switched by rotation, the above-described straight lines A and B are formed so as to coincide with the straight line connecting the center of the light source 3 and the focal point of the condenser lens 5. .

  In this way, it is possible to use the first opening 21 as the exit or the second opening 22 as the exit without lowering the light utilization efficiency described above. It becomes possible to invert easily and precisely.

<Image projection by projector 1>
The projector 1 of the present embodiment projects a desired image based on the following principle. That is, as shown in FIG. 1, the light emitted from the light source 3 is reflected and collected by the parabolic surface portion 4 a of the reflector 4, and the collected light and the direct light from the light source 3 are converted into the condenser lens 5. Then, the light is further condensed to become a light beam, which enters the entrance of the light tunnel 6. The light beam that has entered the light tunnel 6 is repeatedly reflected and made uniform by the planes 23, 24, 25, and 26 inside the light tunnel 6. Then, when the light that has been made uniform and the unevenness in illuminance is reduced is emitted from the emission port of the light tunnel 6, the light is emitted in a shape having the same aspect ratio as the shape of the emission port. The light emitted from the emission port passes through the color wheel 8. Here, the RGB three color light is sent to the downstream side in time series by the RGB three primary color filters. The light passing through the color wheel 8 is sent to the DMD 10 by the relay lens 9. The relay lens 9 converts incident light into parallel light. The light incident on the DMD 10 is modulated and reflected to a color image by a number of micromirrors integrated on one chip of the DMD 10. This is because the inclination of the micromirror is switched in synchronization with the emission timing of the light of the three primary colors of RGB by the color wheel 8. The light modulated and reflected by the DMD 10 passes through the projection lens 11, and the light magnified by the projection lens 11 is projected onto a screen or the like.

  The aspect ratio of the image projected as described above is determined depending on the aspect ratio of the exit of the light tunnel 6. Therefore, in the case of the present embodiment, if the first opening 21 is the exit, the aspect ratio of the projected image is 16: 9, and if the light tunnel 6 is reversed and the second opening 22 is the exit, The aspect ratio of the projected image is 4: 3.

  Therefore, according to the projector 1 of the present embodiment, it is possible to select a desired aspect ratio from two different aspect ratios and project an image having the selected aspect ratio.

[Features of the projector 1]
(1)
As shown in FIG. 2, the projector 1 according to the present embodiment modulates light emitted from a light source 3 that emits light for displaying a projected image, a light tunnel 6, and an exit of the light tunnel 6. The light tunnel has two openings (first opening 21 and second opening 22) having different aspect ratios.

As a result, it is possible to project images having different aspect ratios between the case where the first opening 21 is used as the exit and the case where the second opening 22 is used as the exit.
As a result, it is possible to project images having different aspect ratios with a smaller number of components than in the past.

(2)
As shown in FIG. 5, the projector 1 according to the present embodiment includes a rotation shaft 31 at the center of the one surface 30 outside the light tunnel 6 as a rotation mechanism for rotating the light tunnel 6.

Thereby, the first opening 21 and the second opening 22 can be easily reversed.
As a result, the aspect ratio of the projected image can be converted easily and quickly.

(3)
In the projector 1 of the present embodiment, as shown in FIG. 5, the rotation width of the light tunnel 6 is limited, and the locking portion 32 and the locked portions 33 a and 33 b for fixing the stationary position of the light tunnel 6 are provided. have.

As a result, the fixed position of the light tunnel 6 is precisely determined even before and after inversion, so that the light from the light source 3 installed upstream is not shifted and incident on the entrance, and at the same time installed downstream. The positional deviation of the incident light on the color wheel 8 and the relay lens 9 is eliminated.
As a result, the use efficiency of light is not unnecessarily lowered, and the positional deviation of the irradiated area of the DMD 10 is also eliminated, so that it is possible to eliminate the lack or deviation of the projected image.

(4)
As shown in FIG. 4, the projector 1 according to the present embodiment includes the reflector 4 and the condenser lens 5 that converge the light emitted from the light source 3 toward the entrance of the light tunnel 6. The shape when the incident light enters the entrance is a shape inscribed in the opening having the smaller area of the first opening 21 and the second opening 22 of the light tunnel 6. That is, in the present embodiment, when the converged light enters the incident port, the shape is inscribed in the second opening 22.

Thereby, in any case where the first opening 21 or the second opening 22 is used as the entrance, the light emitted from the light source 3 enters the inside of the light tunnel 6.
As a result, loss of light emitted from the light source 3 is reduced, light utilization efficiency is increased, and a high-luminance image can be projected.

(Embodiment 2)
A projector 2 according to another embodiment 2 of the present invention will be described with reference to FIGS. 6 (a) to 6 (d) and FIG. In addition, detailed description is abbreviate | omitted about the structure similar to Embodiment 1, and shall attach | subject the same code | symbol also about a code | symbol.

[Overall configuration of projector 2]
The projector 2 of this embodiment is a one-chip DLP projector 2 using a DMD 10 configured by arranging a plurality of micromirrors on a semiconductor, similar to the projector 1 described above. , A reflector 4, a condenser lens 5, a light tunnel 40, a color wheel 8, a relay lens 9, a DMD 10, and a projection lens 11. Further, the light tunnel 40 of the present embodiment has a variable portion (glass flat plates 45 and 46), and the projector 2 includes an aspect ratio setting mechanism 50 for displacing the variable portion.

  Since the light source 3, the reflector 4, the condenser lens 5, the color wheel 8, the relay lens 9, the DMD 10, and the projection lens 11 in the present embodiment are the same as the projector 1, description thereof is omitted.

  The light tunnel 40 is provided in order to repeat the reflection of light that has been collected by the condensing lens 5 and to make light uniform, that is, to eliminate unevenness in illumination, and the light tunnel 40 has on the downstream side. Since the shape of the light at the light exit has an imaging relationship with the mirror surface of the DMD 10, it plays a role in determining the aspect ratio of the projected image. The configuration of the light tunnel 40 and the variable portion aspect ratio setting mechanism 50 will be described below.

[Configuration and location of light tunnel 40]
The light tunnel 40 according to the present embodiment is mounted on the projector 2 described above to determine the optical integrator and the aspect ratio of the projected image, and as shown in FIGS. 6 (a) to 6 (d), A cylindrical shape having an entrance 41 and an exit 42 is formed. However, FIGS. 6C and 6D show a state in which the variable portion is displaced to make the emission port 42 smaller, that is, a state in which the aspect ratio is changed, as compared to FIGS. 6A and 6B. Show.

  The light tunnel 40 is formed into a cylindrical shape by four glass flat plates 43, 44, 45, and 46. Therefore, this light tunnel 40 has two sets of planes 43a, 44a, 45a, and 46a facing inward, and these planes 43a, 44a, 45a, and 46a are mirror surfaces that totally reflect incident light. It has become. Therefore, in the present embodiment, the respective end portions of the two sets of opposed planes 43a, 44a, 45a, 46a form the entrance 41 and the exit 42.

  The pair of opposed planes 43a and 44a out of the two pairs of opposed planes 43a and 44a and 45a and 46a are parallel to each other and parallel to the horizontal plane. On the other hand, the other pair of opposing flat surfaces 45a and 46a are rotatably attached with the end portions 45b and 46b on the incident port 41 side as fixed ends. However, the angle range of the rotation is limited by an aspect ratio setting mechanism 50 described later, and is a range in which the shape of the emission port 42 keeps a geometrically closed quadrangle. In this case, when the variable portion (glass flat plates 45 and 46) is fixed so that the area of the exit port 42 is smaller than the area of the entrance port 41, the taper is made from the entrance port 41 toward the exit port 42. Thus, the taper shape has a uniform inclination. That is, by changing the glass flat plates 45 and 46 (planes 45a and 46a), the aspect ratio of the exit port 42 can be converted, and the aspect ratio of the irradiated area of the DMD 10 and the aspect ratio of the projected image can be changed. Can be changed. In addition, since the aspect ratio can be converted by one light tunnel 40, the number of constituent members can be reduced as compared with the prior art.

  Next, the arrangement position of the light tunnel 40 (positional relationship with other members) will be described. The light tunnel 40 is disposed so that the entrance 41 is positioned in the vicinity of the focal point of the light (light flux) collected by the condenser lens 5, and more specifically, the shape of the light flux (in the traveling direction of the light flux). The vertical cross-sectional shape is inscribed in the entrance 41 (see FIG. 4). The straight line connecting the center of the entrance 41 and the center of the exit 42 is arranged so as to coincide with the straight line connecting the center of the light source 3 and the focal point of the condenser lens 5. In this way, the light emitted from the light source 3 is incident on the inside of the light tunnel 40 with high efficiency, so that the utilization efficiency of the light from the light source 3 is increased and the brightness of the projected image is improved.

[Configuration of aspect ratio setting mechanism 50]
Next, an aspect ratio setting mechanism 50 for displacing the planes 45a and 46a of the light tunnel 40, that is, an aspect ratio setting mechanism 50 for changing the aspect ratio of the emission port 42 will be described with reference to FIG. As shown in FIG. 7, the aspect ratio setting mechanism 50 includes an electromagnet 51, a magnetic part 52, and a connecting part 53. Here, since it is bilaterally symmetric, only one aspect ratio setting mechanism 50 will be described.

The connecting portion 53 is a member that connects the magnetic body portion 52 and the glass flat plate 45, and is disposed in the vicinity of the end of the glass flat plate 45 on the emission port 42 side.
The magnetic body portion 52 is a plate-type magnetic member, and is disposed substantially in parallel with the glass flat plate 45, and one plane is fixed to the connecting portion 53. The length in the vertical direction is designed to be longer than the distance between the non-variable plane 44a and the plane 43a. In this case, when the glass flat plate 45 is displaced inward, the plane on the light tunnel 40 side of the magnetic body portion 52 hits the side surfaces 43b and 44b of the glass flat plates 43 and 44 of the non-variable portion. Therefore, the displacement range of the plane 45a to the inside of the light tunnel 40 is determined.

  The electromagnet 51 is a magnet whose polarity can be freely changed depending on the current flowing in the electromagnet 51. In the present embodiment, the electromagnet 51 is arranged at a predetermined distance from the magnetic body portion 52. . Thereby, when the flat surface 45a is displaced in the outer direction of the light tunnel 40, the magnetic body portion 52 and the electromagnet 51 come into contact with each other, so that the displacement range of the flat surface 45a in the outer direction of the light tunnel 40 is determined. Further, depending on the characteristics of the electromagnet, it is possible to freely select a state in which the magnetic body portion 52 is in contact with the electromagnet 51 or a state in which it is separated.

  According to such a configuration of the aspect ratio setting mechanism 50, the displacement range to the inside and outside of the light tunnel 40 is determined for the flat surface 45a which is a variable portion. Then, by designing the aspect ratio of the exit port 42 in the innermost displaced state and the aspect ratio of the exit port 42 in the outermost displaced state to predetermined values, the two predetermined designed Any one of the aspect ratios can be freely selected by operating the electromagnet. However, within this variable range, the magnetic body portion 52 is set to have a distance, a magnetic force, and the like between the constituent members so as to be sufficiently affected by the magnetic force of the electromagnet 51.

[Features of the projector 2]
(1)
As shown in FIGS. 6A to 6D, the projector 2 according to the present embodiment includes a light tunnel 40 having a variable portion (glass flat plates 45 and 46) that can change the aspect ratio of the emission port 42. ing.

As a result, the aspect ratio of the exit port 42 can be changed to a desired aspect ratio, so that an image having a desired aspect ratio can be projected by one light tunnel 40.
As a result, it is possible to project images having different aspect ratios with a smaller number of components than in the past.

(2)
As shown in FIG. 7, the projector 2 according to the present embodiment includes an aspect ratio setting mechanism 50 that displaces the glass flat plates 45 and 46 that are variable portions of the light tunnel 40.

Thereby, the planes 45a and 46a can be easily displaced, and the aspect ratio of the exit port 42 can be changed.
As a result, the aspect ratio of the projected image can be converted easily and quickly.

[Other Embodiments]
(A)
In the first and second embodiments, an example in which an ultrahigh pressure mercury lamp is used as an example of the light source 3 has been described. However, the present invention is not limited to this.
For example, an electrodeless discharge lamp, a xenon short arc lamp, a metal halide lamp, a light emitting diode, or the like may be used.

(B)
In the said Embodiment 1, 2, the example which uses crystallized glass as an example of the material of the reflector 4 was given and demonstrated. However, the present invention is not limited to this.
For example, borosilicate glass or the like may be used in consideration of cost.

(C)
In the first embodiment, the inclined portion of the light tunnel 6 has been described as a pair of planes 23 and 25 facing each other. However, the present invention is not limited to this.
For example, the inclined portion of the light tunnel may be only one surface or all four surfaces.

(D)
In the said Embodiment 1, the edge part 31b of the rotating shaft 31 demonstrated as being rotatably attached to the housing | casing. However, the present invention is not limited to this.
For example, a motor may be connected to the end of the rotating shaft, and the motor may be rotatable.

(E)
In the second embodiment, the aspect ratio setting mechanism 50 is the electromagnet 51, the magnetic part 52, and the connecting part 53. However, the present invention is not limited to this.
For example, the variable portion may be displaced using a stepping motor or the like.

(F)
In the second embodiment, the displacement by the aspect ratio setting mechanism 50 has been described as two states. However, the present invention is not limited to this.
For example, the projection image may have three states in which the aspect ratio of the projected image can be selected from any one of 16: 9, 4: 3, and 2.4: 1.

(G)
In the first embodiment, the description has been given of the configuration in which the shape of the light beam entering the entrance is inscribed in the opening having the smaller area of the first opening 21 and the second opening 22. However, the present invention is not limited to this.
For example, if the light source 3 is sufficiently bright, it may be configured to circumscribe the larger opening portion of the first opening portion 21 and the second opening portion in order to reduce illuminance unevenness. .

(H)
In the second embodiment, the configuration of the light beam incident on the incident port 41 has been described as being inscribed in the incident port 41. However, the present invention is not limited to this.
For example, if the light source 3 is sufficiently bright, a configuration circumscribing the entrance 41 may be used in order to reduce illuminance unevenness.

  The projection apparatus according to the present invention includes a light tunnel as a constituent member in order to produce an effect that the aspect ratio of an image to be projected can be easily changed and the number of constituent members can be reduced even with a single light tunnel. The present invention can be widely applied to image display devices and the like.

It is a block diagram which shows the structure of the optical member of the projector which concerns on Embodiment 1 of this invention. It is a perspective view which shows the external appearance of the light tunnel contained in the projector of FIG. (A) is a side view top view by the side of the 1st opening part of the light tunnel of FIG. FIG. 3B is a side plan view of the light tunnel of FIG. 2 on the second opening side. (C) is a side view plan view of the light tunnel of FIG. 2. FIG. 3D is a top plan view of the light tunnel of FIG. It is the schematic which shows the shape of the light from the light source in Embodiment 1 to a light tunnel. (A) is a side view top view which shows the light tunnel and rotation mechanism in Embodiment 1. FIG. (B) is the CC sectional drawing. (A) is a side view top view of the exit side of the light tunnel in Embodiment 2. FIG. (B) is a top view transmission diagram of the light tunnel. (C) is a side view plan view of the exit side of the light tunnel in the second embodiment. (D) is a top view transmission diagram of the light tunnel. It is a side view top view from the exit port side of the light tunnel and aspect ratio setting mechanism in Embodiment 2 of this invention.

Explanation of symbols

1 Projector (Projector)
2 Projector (Projector)
DESCRIPTION OF SYMBOLS 3 Light source 4 Reflector 4a Parabolic surface part 5 Condensing lens 6 Light tunnel 7 Rotating mechanism 8 Color wheel 9 Relay lens 9a Plane mirror 10 DMD (optical modulation element)
DESCRIPTION OF SYMBOLS 11 Projection lens 21 1st opening part 22 2nd opening part 23 Plane 24 Plane 25 Plane 26 Plane 27 Focal point 28 Center of 1st opening part 29 Center of 2nd opening part 30 One surface 31 Rotating shaft 31b End part 32 Locking part 33a Locked portion 33b Locked portion 34a Recessed portion 34b Recessed portion 40 Light tunnel 41 Entrance port 42 Output port 43 Glass flat plate 43a Flat surface 43b Side surface 44 Glass flat plate 44a Flat surface 44b Side surface 45 Glass flat plate 45a Flat surface 45b End portion 46 Glass flat plate 46a Plane 46b End 50 Aspect ratio setting mechanism 51 Electromagnet 52 Magnetic body portion 53 Connection portion

Claims (11)

A light source that emits light for displaying a projected image;
An incident port through which light is incident from the light source; and an emission port that emits light incident on the incident port and whose shape determines the aspect ratio of the projection image. A light tunnel with a different aspect ratio from the mouth;
An optical modulation element for modulating the light emitted from the emission port;
A projection apparatus comprising: A rotation mechanism that reverses the entrance and the exit of the light tunnel;
The projection apparatus according to claim 1. It further includes a rotation axis that serves as a rotation center of the light tunnel,
The projection apparatus according to claim 1 or 2. A locking portion for positioning the incident port and the exit port;
A locked portion formed in the light tunnel;
Further equipped with,
The projection apparatus of any one of Claim 1 to 3. Further comprising a focusing unit for focusing the light emitted from the light source upstream of the light tunnel,
The light beam incident on the incident port is inscribed in the shape of the smaller one of the incident port and the exit port,
The projection device according to any one of claims 1 to 4. On the inner surface of the light tunnel, there are two sets of opposing planar mirror surface portions,
It further comprises an operating mechanism for adjusting the distance between the facing mirror surface portions.
The projection apparatus according to claim 1. A light source that emits light for displaying a projected image;
An incident port through which light is incident from the light source, an exit port that emits light incident on the incident port, and an exit port whose shape determines an aspect ratio of the projection image, and an aspect ratio of the exit port to a desired aspect ratio A light tunnel having a variable portion to be changed, and
An optical modulation element for modulating the light emitted from the emission port;
A projection apparatus comprising: The inner surface of the light tunnel has two sets of planar mirror surface portions facing each other,
The variable portion includes at least one mirror surface portion of the mirror surface portions.
The projection device according to claim 7. An aspect ratio setting mechanism for displacing the variable portion;
The projection device according to claim 7 or 8. A color wheel is further provided on the upstream side or the downstream side of the light tunnel,
The projection device according to claim 1. The optical modulation element is a digital micromirror device;
The projection device according to claim 1.

Images