JP2011164479A - Projection apparatus - Google Patents

Abstract

An illumination optical system having a simple configuration that can adjust the irradiation size of an illumination light beam and effectively utilize the brightness of a light source.
A mirror 51 is inserted in an optical path from a light source through an image display element to a projection lens and bends the optical path, a holding block 52 that holds the mirror 51 at a predetermined angle above the block, and the holding block 52 A substantially hemispherical fulcrum member 53 attached to the bottom surface side, a base plate 54 formed with a circular recess 54A having a smaller diameter than the fulcrum member as a fulcrum member receiver, and attached to the bottom surface of the holding block 52 through the base plate 54 A plurality of adjustment screws 55 and 55 for fixing the relative angle between the block 52 and the base plate 54, and a screw shaft 56 as an adjustment mechanism for adjusting the relative distance between the holding block 52 and the base plate 54 to vary the optical path length. An adjustment mirror part is provided.
[Selection] Figure 3

Description

  The present invention relates to a projection apparatus having a reflecting member in an illumination optical system.

  FIG. 9 is a plan view showing a configuration of a projector device 10 of a DLP (Digital Light Processing) (registered trademark) system using a micromirror element. In the figure, a high-pressure mercury lamp 12 serving as a light source is disposed in a reflector 11 whose inner surface is mirror-finished. High-intensity white light is generated by driving the high-pressure mercury lamp 12 with an AC high-voltage power source.

  The light generated by the high-pressure mercury lamp 12 is extracted directly or after being reflected from the inner surface of the reflector 11 as a light beam, and after being reflected by the first mirror 13, it is applied to the rotating color wheel 15 via the lamp lens 14.

  In the color wheel 15, the disk-shaped face wall portion rotated by the color wheel motor 16 is formed of red (R), green (G), and blue (B) fan-shaped color filters. Therefore, when the color wheel 15 is rotated by the color wheel motor 16, the white light passing through the color wheel 15 is extracted in a time-division manner in a frequency band in a time-division manner as R, G, and B primary color lights. Is output.

  The primary color lights of R, G, and B through the color wheel 15 are repeatedly irregularly reflected inside when passing through the light tunnel 17, and after the light flux density distribution is averaged, the light is reflected by the second mirror 19 through the illumination system lens 18. After being reflected and reflected by the third mirror 21 via the illumination system lens 20, the micromirror element 23 is irradiated via the field lens 22.

  The micromirror element 23 is a display element that is also called DMD (Digital Micromirror Device) (registered trademark). The micromirror element 23 performs a display operation by individually turning on / off each inclination angle of a plurality of micromirrors corresponding to the number of pixels arranged in an array, for example, XGA (1024 horizontal pixels × 768 vertical pixels) at high speed. Thus, an optical image is formed by the reflected light.

  The optical image formed by the reflected light from the micromirror element 23 is sent to the projection lens unit 24 via the field lens 22. The projection lens unit 24 has three lens configurations of the first lens group 24A, the second lens group 24B, and the third lens group 24C from the objective side, and enlarges the optical image formed by the micromirror element 23. To project onto a screen (not shown) to be projected.

  The specific configuration of the third mirror 21 that guides the illumination light beam to the micromirror element 23 in the configuration of FIG. 9 will be described with reference to FIG. As shown in FIG. 10, the third mirror 21 is fixed on the mirror block 31 to maintain an angle with respect to the illumination light beam.

  A substantially hemispherical fulcrum member 32 is integrally formed at the center of the bottom surface of the mirror block 31 so as to project. The mirror block 31 includes a plurality of, three or more angle adjusting screws 34, 34 such that the curved surface side of the fulcrum member 32 is in contact with a circular hole 33A formed in the base plate 33 attached to the projector device side. ,... Are fixed to the base plate 33.

  The circular hole 33A need not be a through hole as long as it has a depth corresponding to at least the substantially hemispherical curved surface of the fulcrum member 32, and may be a circular depression.

  The through holes for the angle adjusting screws 34, 34,... Formed in the base plate 33 have a larger diameter than the shaft portions of the angle adjusting screws 34, 34,.

  That is, the curved surface side of the substantially hemispherical fulcrum member 32 of the mirror block 31 is brought into contact with and slides with respect to the circular hole 33A of the base plate 33, and the angles of the third mirror 21 and the mirror block 31 with respect to the base plate 33 are changed. After the adjustment, the angle adjusting screws 34, 34,... Are screwed together to fix the space between the bottom bottom surface of the mirror block 31 and the base plate 33, whereby the third mirror 21 and the mirror block 31 with respect to the base plate 33 are fixed. The angle is fixed.

  Prior to factory shipment, the third mirror 21 is accurately adjusted in angle so that a larger part of the illumination light beam transmitted through the illumination system lens 20 is reflected to the micromirror element 23 side, and the reflected light. The optical image formed in (4) reaches the projection lens unit 24 side.

  However, as described above, since the third mirror 21 can only adjust the angle within the same diameter range with the fulcrum member 32 as a fulcrum, the irradiation size cannot be adjusted. The angle adjustment of the third mirror 21 that leads to the micromirror element 23 is very important and severe.

  In this type of projector device 10, the size of the light beam applied to the micromirror element 23 is sufficiently large with respect to the display area of the micromirror element 23 in consideration of the error of each member constituting the illumination optical system. Designed to be For this reason, the brightness of the light source cannot be used efficiently, and there is a problem that stray light or the like is generated by the light flux that cannot be used.

  Conventionally, in an illumination optical system that illuminates an image display element with a light beam from a light source, the illumination optical system has a negative meniscus lens that is convex on the light source side and a biconvex positive lens, and the distance between the two lenses. A technique has been considered in which the size of the illumination area in the image display element is changed by changing. (For example, Patent Document 1)

JP 2002-296538 A

  When the technique described in the above-mentioned patent document is adopted, the illumination optical system shown in FIG. 9 further incorporates two optical lenses and a movable mechanism for moving them along the optical path direction. In addition, there is a problem that it is complicated and the entire apparatus becomes large.

  The present invention has been made in view of the above circumstances, and its object is to make it possible to adjust the irradiation size of the illumination light flux while making the illumination optical system as simple as possible, and to effectively improve the brightness of the light source. It is an object of the present invention to provide a projection apparatus that can be used in the future.

  The invention according to claim 1 displays a light source, an input unit for inputting an image signal, an image based on the image signal input by the input unit, and reflects or transmits light obtained from the light source to produce an optical image. An image display element that forms an image, a projection lens that projects a light image formed by the image display element toward a projection target, and an optical path that is inserted into an optical path from the light source through the image display element to the projection lens. A holding block that holds the mirror at a predetermined angle at the top of the block, a substantially hemispherical fulcrum member attached to the bottom side of the holding block, and a circular recess having a smaller diameter than the fulcrum member as a fulcrum member receiver The formed base plate, a plurality of adjusting screws that pass through the base plate and are attached to the bottom surface of the holding block and fix the relative angle between the holding block and the base plate, and the holding block and the base By adjusting the relative distance, characterized by comprising an adjustment mirror portion having an adjustment mechanism for varying the optical path length.

  According to a second aspect of the present invention, in the first aspect of the invention, the adjusting mirror portion is provided at a position in the optical path immediately before the light from the light source is incident on the image display element. And

  According to a third aspect of the present invention, in the first aspect of the present invention, the adjustment mechanism of the adjustment mirror portion is configured such that the other end side of the screw portion having the fulcrum member attached to one end side is screwed to the bottom surface side of the holding block. The axial length of the threaded portion protruding from the holding block is adjusted.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the adjustment mechanism of the adjustment mirror portion is configured such that a part of the base plate main body provided with a circular recess serving as the fulcrum member receiver is a screw mechanism. It moves in the plate thickness direction.

  According to the present invention, it is possible to adjust the irradiation size of the illumination light beam while making the illumination optical system as simple as possible, and to effectively use the brightness of the light source.

FIG. 3 is a plan view showing an optical path configuration of the projector device according to the embodiment of the invention. The perspective view which shows the structure of the 3rd mirror which concerns on the embodiment, a field lens, and a micromirror element periphery. The side view which shows the attachment structure of the 3rd mirror which concerns on the same embodiment. The side view which shows the attachment structure of the 3rd mirror which concerns on the same embodiment. The side view which shows the attachment structure of the 3rd mirror which concerns on the same embodiment. The side view which shows the attachment structure of the 3rd mirror which concerns on the other structural example of the embodiment. The side view which shows the attachment structure of the 3rd mirror which concerns on the other structural example of the embodiment. The side view which shows the attachment structure of the 3rd mirror which concerns on the other structural example of the embodiment. The top view which shows the optical path structure of the projector apparatus of a general DLP (trademark) system. The figure which shows the structure which adjusts the attachment angle of the 3rd mirror of FIG.

  Hereinafter, an embodiment in which the present invention is applied to a DLP (registered trademark) projector apparatus using a micromirror element will be described with reference to the drawings.

  FIG. 1 is a plan view showing a configuration of a projector device 50 according to the present embodiment. Since this figure is basically almost the same as the contents shown in FIG. 9, the same parts are denoted by the same reference numerals and their description is omitted.

  Then, in place of the third mirror 21 described in FIG. 10, a third mirror 51 whose position can be adjusted as shown by an arrow A in the drawing is used.

  FIG. 2 is a perspective view showing a configuration around the third mirror 51, the field lens 22, and the micromirror element 23. FIG. In the figure, the third mirror 51 is fixed on the mirror block 52 and maintains an angle with respect to the illumination light beam.

  A substantially hemispherical fulcrum member 53 (not shown here), which will be described later, is attached to the bottom bottom center of the mirror block 52 so as to project. The mirror block 52 includes a plurality of, for example, three angle adjusting screws 55 such that the outer curved surface side of the fulcrum member 53 comes into contact with a circular hole 54A formed in the base plate 54 attached to the projector device 50 side. , 55, 55 are fixed to the base plate 54.

  The circular hole 54A is not necessarily a through hole as long as it has a depth corresponding to at least the substantially hemispherical curved surface of the fulcrum member 53, and may be a circular depression.

  The through holes 54B, 54B, 54B for the angle adjusting screws 55, 55, 55 formed in the base plate 54 all have a sufficiently larger diameter than the shaft portions of the angle adjusting screws 55, 55, 55, and play. It becomes a penetrating state.

  That is, the curved surface portion of the substantially hemispherical fulcrum member 53 attached to the bottom surface side of the mirror block 52 is brought into contact with and slides with respect to the circular hole 54A of the base plate 54, and the third mirror 51 and the base plate 54 After adjusting the angle of the mirror block 52, the angle adjusting screws 55, 55, 55 are all screwed together to fix the distance between the bottom bottom surface of the mirror block 52 and the base plate 54, whereby the third mirror with respect to the base plate 54 is fixed. The angles of 51 and the mirror block 52 are fixed.

  Corresponding to the angle adjustment of the third mirror 51 and the mirror block 52, the through holes 54B, 54B, 54B for the angle adjusting screws 55, 55, 55 drilled in the base plate 54 as described above have a sufficient margin. The angle adjustment screws 55, 55, 55 are formed to have an inner diameter larger than the shaft diameter.

  FIG. 3 shows a side configuration of a set of units including the third mirror 51. As shown in the figure, the fulcrum member 53 is attached to the bottom surface side of the mirror block 52 via a screw shaft 56. While the fulcrum member 53 and the screw shaft 56 are integrated, the screw shaft 56 is screwed into a screw hole formed in the bottom surface of the mirror block 52, so that the screw shaft 56 protruding from the bottom surface of the mirror block 52 is formed. The shaft length and the position of the fulcrum member 53 can be adjusted. FIG. 3 shows a state in which the reflecting surface of the third mirror 51 coincides with the initial design position P.

  Note that the third mirror 51 and the mirror block 52 may have an integrated structure. Further, the fulcrum member 53 and the screw shaft 56 may be integrated.

  FIG. 4 shows a state in which the screw shaft 56 is screwed into the mirror block 52 so that the protruding shaft length is shorter and then assembled to the base plate 54 with the angle adjusting screws 55, 55, 55. As shown in the figure, the incoming light from the light source side is reflected by the third mirror 51 after exceeding the design position P and guided to the micromirror element 23 via the field lens 22.

  Therefore, at the adjustment position of the mirror block 52 as shown in FIG. 4, the optical path of the light source light incident on the micromirror element 23 is smaller than the adjustment position P of the designed mirror block 52 shown in FIG. Can be extended.

  Further, in FIG. 5, contrary to FIG. 4, the screw shaft 56 is screwed into the base plate 54 with the angle adjusting screws 55, 55, 55 after being screwed so that the protruding shaft length of the screw shaft 56 with respect to the mirror block 52 becomes longer. The assembled state is shown. As shown in the drawing, the incoming light from the light source side is reflected by the third mirror 51 on the near side from the design position P and guided to the micromirror element 23 through the field lens 22.

  Therefore, at the adjustment position of the mirror block 52 as shown in FIG. 5, the optical path of the light source light incident on the micromirror element 23 is smaller than the adjustment position P of the designed mirror block 52 shown in FIG. It can be shortened.

  3 to 5 have been described with respect to the adjustment position in which the screw shaft 56 is orthogonal to the plane of the base plate 54, but of course, it is in contact with the circular hole 54A of the fulcrum member 53. And the through holes 54B, 54B, 54B on the base plate 54 side for the angle adjusting screws 55, 55, 55 are sufficient for the shaft diameter of the angle adjusting screws 55, 55, 55. Since there is a margin, it is possible to adjust the angle with respect to the incoming optical axis with the fulcrum member 53 as the center, similar to the contents shown in FIGS. 9 and 10 above.

  As described above, according to the present embodiment, it is possible to adjust the irradiation size of the illumination light flux by changing the illumination optical path length while making the illumination optical system as simple as possible, and to effectively use the brightness of the light source. It becomes possible.

  In the above-described embodiment, the optical path length can be variably adjusted in the third mirror 51 that is positioned immediately before the micromirror element 23 in the optical path and guides the light from the light source to enter the micromirror element 23. In addition, it is possible to appropriately set the light beam range when forming the optical image with the micromirror element 23, and to realize the projection using the light quantity from the light source more effectively.

  Furthermore, in the above embodiment, since the optical path length can be adjusted by changing the axial length of the screw shaft 56 that attaches the fulcrum member 53 to the mirror block 52, the length of the shaft of the screw shaft 56 embedded in the mirror block 52 is increased. Accordingly, the adjustment range can be set relatively wide, and the optical path length can be adjusted larger.

Note that a configuration that replaces the configuration described in FIGS. 3 to 5 will be described as another configuration example of the present embodiment.
FIG. 6 shows another side configuration of the unit set including the third mirror 51. As shown in the figure, the fulcrum member 53 is fixedly attached to the bottom surface side of the mirror block 52. On the other hand, the portion 54D including the circular hole 54A of the base plate 54 'with which the fulcrum member 53 abuts has a screw structure that can move in the thickness direction with respect to the surrounding base plate 54'. . In FIG. 3, the reflecting surface of the third mirror 51 coincides with the initial design position P, and together with this, the front and back surfaces of the base plate 54 'coincide with those of the circular hole forming portion 54D. .

  The third mirror 51, the mirror block 52, and the fulcrum member 53 may have an integral structure.

  In FIG. 7, after the circular hole forming portion 54 </ b> D is moved (screwed) so that the circular hole forming portion 54 </ b> D moves backward on the side opposite to the mirror block 52 with respect to the base plate 54 ′, the angle adjusting screw 55. , 55, 55 show a state in which the mirror block 52 and the base plate 54 are assembled. As shown in the figure, the incoming light from the light source side is reflected by the third mirror 51 after exceeding the design position P and guided to the micromirror element 23 via the field lens 22.

  Therefore, in the adjustment position of the mirror block 52 as shown in FIG. 7, the optical path of the light source light incident on the micromirror element 23 is smaller than the adjustment position P of the designed mirror block 52 shown in FIG. Can be extended.

  Further, in FIG. 8, contrary to FIG. 7, the circular hole forming portion 54 </ b> D is moved (screwed) so that the circular hole forming portion 54 </ b> D is advanced by the mirror block 52 side with respect to the base plate 54 ′. The state in which the mirror block 52 and the base plate 54 are assembled by the angle adjusting screws 55, 55, 55 is shown. As shown in the drawing, the incoming light from the light source side is reflected by the third mirror 51 on the near side from the design position P and guided to the micromirror element 23 through the field lens 22.

  Therefore, at the adjustment position of the mirror block 52 as shown in FIG. 8, the optical path of the light source light incident on the micromirror element 23 is smaller than the adjustment position P of the designed mirror block 52 shown in FIG. It can be shortened.

  6 to 8 have been described with respect to the adjustment position where the screw shaft 56 is orthogonal to the plane of the base plate 54, of course, it is in contact with the circular hole 54A of the fulcrum member 53. And the through holes 54B, 54B, 54B on the base plate 54 'side for the angle adjusting screws 55, 55, 55 are sufficient for the shaft diameter of the angle adjusting screws 55, 55, 55. Since there is a sufficient margin, the angle can be adjusted with respect to the incoming optical axis with the fulcrum member 53 as the center, which is the same as the contents shown in FIG. 9 and FIG.

  As described above, according to the present embodiment, since the optical path length can be adjusted by moving the position of the circular hole forming portion 54D on the base plate 54 'side, the third mirror 51 and the mirror with respect to the base plate 54' can be adjusted. From the state where the block 52 and the fulcrum member 53 are loosely assembled by the angle adjusting screws 55, 55, 55, from the right side in FIGS. 6 to 8 to the circular hole forming portion 54D, that is, from the back side where the mirror block 52 is not attached. Adjustment is possible by rotating the circular hole forming portion 54D, and the work required for adjusting the optical path length and the angle of the third mirror 51 can be simplified.

  In the above-described embodiment, the case where the present invention is applied to a DLP (registered trademark) type projector device using a micromirror element has been described. However, the present invention is a projector method using an element serving as a light source, an image display element, or The present invention is not limited to a single plate type or a three plate type, and can be applied to any projection apparatus that uses a mirror that can adjust the optical path length and reflection angle.

  In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention in the implementation stage. Further, the functions executed in the above-described embodiments may be combined as appropriate as possible. The above-described embodiment includes various stages, and various inventions can be extracted by an appropriate combination of a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the effect is obtained, a configuration from which the constituent requirements are deleted can be extracted as an invention.

  DESCRIPTION OF SYMBOLS 10 ... Projector apparatus, 11 ... Reflector, 12 ... High pressure mercury lamp, 13 ... 1st mirror, 14 ... Lamp lens, 15 ... Color wheel, 16 ... Color wheel motor, 17 ... Light tunnel, 18 ... Illumination system lens, 19 ... 2nd mirror, 20 ... illumination system lens, 21 ... 3rd mirror, 22 ... field lens, 23 ... micromirror element (DMD), 24 ... projection lens unit, 24A-24C ... lens group, 31 ... mirror block, 32 ... Fulcrum member 33 ... base plate 33A ... circular hole 34 ... angle adjusting screw 50 ... projector device 51 ... third mirror 52 ... mirror block 53 ... fulcrum member 54, 54 '... base plate 54A ... Circular hole, 54B ... through hole, 54D ... circular hole forming part, 55 ... angle adjusting screw, 56 ... screw shaft, 61 ..., 62 ..., 63 ..., 6 ..., 65 ..., P ... design position.

Claims (4)

A light source;
An input unit for inputting an image signal;
An image display element that displays an image based on an image signal input by the input unit, and reflects or transmits light obtained from the light source to form a light image;
A projection lens that projects a light image formed by the image display element toward a projection target;
A mirror that is inserted into the optical path from the light source through the image display element to the projection lens and bends the optical path, a holding block that holds the mirror at a predetermined angle at the top of the block, and an abbreviation attached to the bottom side of the holding block A hemispherical fulcrum member, a base plate formed as a fulcrum member receiver with a circular recess having a smaller diameter than the fulcrum member, and attached to the bottom surface of the holding block through the base plate, fixing the relative angle between the holding block and the base plate A projection apparatus comprising: a plurality of adjustment screws, and an adjustment mirror unit having an adjustment mechanism that adjusts a relative distance between the holding block and the base plate to vary the optical path length.   The projection apparatus according to claim 1, wherein the adjustment mirror unit is provided at a position in the optical path immediately before the light from the light source is guided and incident on the image display element.   The adjusting mechanism of the adjusting mirror unit is configured to adjust the axial length of the screw part protruding from the holding block by screwing the other end side of the screw part with the fulcrum member attached to one end side to the bottom side of the holding block. The projection apparatus according to claim 1.   2. The projection according to claim 1, wherein the adjustment mechanism of the adjustment mirror portion is configured such that a part of the base plate body provided with a circular depression serving as the fulcrum member is moved in the plate thickness direction by a screw mechanism. apparatus.

Images