JP2006343512A - Diaphragm device for projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm device for a projector, the diaphragm device being designed so as to be compactly disposed near a light source lamp and intercept an optical path without reflecting light from the light source towards the light source. <P>SOLUTION: A motor 4 has a gear 5 attached to an output shaft 4a projecting towards the rear face of a base plate 1. Light intercepting members 8 and 9 made of a synthetic resin are rotatably attached to shafts 6 and 7, respectively, extending vertically toward the rear face of the base plate 1. The teeth 8a of the light intercepting member 8 are engaged with the gear 5, and the teeth 8b of it are engaged with the teeth 9a of the light intercepting member 9. In addition, the light intercepting members 8 and 9 have mounting parts 8c and 9c, respectively, projecting towards the surface of the base plate 1, and light intercepting plates 16 and 19 are mounted on the mounting parts 8c and 9b respectively. The light intercepting plates 16 and 19 are capable of intercepting the optical path of the light of the light source. When located in the optical path, including an intercepting state, the light intercepting plates 16 and 19 do not reflect the light from the light source toward the light source lamp. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a diaphragm device for light source light suitable for use in a projector that projects an image or characters on a transmissive or reflective screen.

  Recently, projectors equipped with a liquid crystal panel, DMD (digital micromirror device), etc. have appeared and are used for various presentations and sales presentations, and are also used as equipment for home theaters. And as this kind of projector, in order to change the illumination light quantity from the light source lamp corresponding to the brightness of the room to project, or to temporarily weaken the illumination light when nothing is projected, Patent Document 1 below describes an optical path area of light source light that is changed by a diaphragm device arranged in the vicinity of the light source lamp without changing the amount of light emitted from the light source lamp itself.

  In particular, in the case of a liquid crystal projector, it is known that deterioration of the liquid crystal panel can be prevented by reducing the illumination light temporarily even by a diaphragm device when nothing is projected. Japanese Patent Application Laid-Open No. H10-228561 describes that a high-contrast image can be obtained by providing such a diaphragm device. Furthermore, in the case of an overhead projector using a variable magnification optical system as the projection optical system, it is possible to suitably obtain a projected image at a high magnification by arranging an aperture device between the stage for placing the document and the light source. Is described in Patent Document 2 below. The present invention relates to a diaphragm device for light source light suitable for use in such projectors.

JP 2004-69966 A JP-A-8-227102

  Incidentally, the diaphragm devices described in Patent Documents 1 and 2 can limit the amount of light emitted from the light source, but are not configured to be completely blocked. Therefore, when used in a liquid crystal projector, it is said that it is sufficient from the viewpoint of preventing the deterioration of the liquid crystal panel because it only minimizes the amount of light when nothing is projected. I want. In recent years, projectors that are directly connected to a personal computer and project an image operated by the personal computer have been increasing. In such projectors, the amount of light is limited in the projection preparation stage. However, an image appearing on the personal computer screen is projected during the operation of the personal computer, which causes the viewer to feel very unsightly. The same can be said for projectors that send or replace film.

  In addition, since the aperture device for the light source light is disposed at a position close to the light source lamp, if the light reflected by the light shielding plate (aperture plate) returns toward the light source lamp, the light source lamp and the light source lamp There are problems in that the optical member disposed between them causes harmful reflections on the projection, and the temperature of the light source lamp is raised to shorten the lifetime. Therefore, in the case of this type of diaphragm device, the light path of the light source light can be blocked as described above, and the light reflected by the light shielding plate (diaphragm plate) returns toward the light source lamp in any state. There is no requirement to have a configuration. Further, in the case of the diaphragm device described in Patent Document 1, the flat plate portions of the two light shielding plates are configured to control the light amount of the light source light like a double door, and in a direction along the optical path. Since a large arrangement space is required, it is required that the light source light can be reflected outside the optical path without increasing the arrangement space as much as possible.

  The present invention has been made to solve such problems, and its object is to place the optical path of the light source light in between and be perpendicular to the optical axis of the optical path and parallel to each other. Two light-shielding members attached to the base plate with the shaft as a rotation axis are simultaneously rotated in different directions, thereby causing the light-shielding plate portions provided on them to advance and retreat from opposite directions into the optical path of the light source light, In the diaphragm device configured to adjust the light amount of the light source light and to reflect the light source light to the outside of the optical path in the optical path, the two light shielding plate portions preferably block the optical path. It is another object of the present invention to provide an aperture device for a projector that can be used.

  In order to achieve the above-mentioned object, the present invention is attached to the base plate arranged on the side of the optical path of the light source light so as to be substantially parallel to the optical path, with the axes being parallel to each other as the rotation axis. By simultaneously rotating the two light shielding members in different directions, the light shielding plate portions provided on the light shielding members are advanced and retracted from opposite directions into the optical path, and the light amount of the light source light is adjusted. The light shielding plate portion is configured to reflect the light source light outside the optical path on the light source side, and the two light shielding plate portions can block the light path while reflecting the light source light outside the optical path. To do.

  In that case, when the two light shielding members are arranged so as to reflect the light source light to the outside of the optical path on the surface of the light shielding plate portion opposite to the rotating shaft side, the reflected light is reflected. The distance to be guided out of the optical path is small. In addition, the two light shielding members are rotated by a single driving source, and the linear distances from the rotation shaft to the entry end of the light shielding plate portion are different from each other so that the light path is blocked. If the both intrusion ends overlap with the optical axis, an optical path blocking state can be effectively obtained. Furthermore, if the light shielding plate portion is formed so that the surface on the light source side has a high reflectance, overheating of the diaphragm device can be suppressed.

  The present invention is for a projector in which two light-shielding members are rotated in different directions so that a light-shielding plate portion provided on the two light-shielding members operates like a double door in the optical path of light source light to control the amount of light. In the diaphragm device, the light-shielding plate portion can not only control the amount of light, but also allows the light path to be blocked, and even in the blocked state, the light source light can be reflected outside the light path. This is extremely effective as a diaphragm device disposed in the vicinity of the light source. If the reflection surface of the light shielding plate portion is the surface opposite to the rotation axis side of the light shielding member, the arrangement space in the projector can be reduced.

  The best mode for carrying out the present invention will be described with reference to the illustrated embodiments. FIG. 1 is a plan view of the embodiment showing a state where the light shielding plate is outside the optical path, and FIG. 2 is a left side view of FIG. 3 is a plan view showing a state where the light path is blocked by the light shielding plate, and FIG. 4 is a left side view of FIG. Further, FIG. 5 is a plan view for explaining the features of the embodiment.

  First, the configuration of this embodiment will be described mainly with reference to FIGS. The base plate 1 of the diaphragm unit in the present embodiment is made of metal, and as shown in FIG. 1, the planar shape is rectangular, and two elongated holes 1a and 1b having an arc shape, Three circular holes 1c, 1d, and 1e are formed. Of these, the three holes 1c, 1d, and 1e are holes for attachment to the projector body. In addition, in a state where the ground plane 1 is attached to the projector main body, light emitted from a light source lamp (not shown) passes from the left to the right as indicated by an arrow in FIG. ing. Therefore, in FIGS. 1, 3, and 5, the optical axis of the light source light (the central axis of the optical path) is indicated by a one-dot chain line. In FIGS. 1, 3 and 5, the effective optical path width is shown by two-dot chain lines on both sides of the optical axis. In FIGS. 2 and 4, the effective optical path (hereinafter simply referred to as the optical path) is shown. The cross section is shown surrounded by a two-dot chain line.

  In FIG. 1, a motor 4 is attached to a position in the vicinity of the upper side of the main plate 1 with two screws 2 and 3. The motor 4 is a step motor, and as can be seen from FIG. 2, the output shaft 4a passes through a hole 1f formed in the main plate 1, and a gear 5 is attached to the tip thereof. Further, two shafts 6 and 7 are erected on the back side of the base plate 1 by caulking, and a first light shielding member 8 made of synthetic resin is rotatably attached to the shaft 6. A second light-shielding member 9 made of synthetic resin is rotatably attached. Further, a cover plate 13 is attached to the back side of the base plate 1 with three screws 10, 11, 12 to prevent the two light shielding members 8, 9 from coming off the shafts 6, 7. In the case of the present embodiment, the optical path side of the base plate 1 is considerably hot, and thus the light shielding members 8 and 9 made of synthetic resin are arranged on the back side as described above. If not, it may be arranged on the optical path side.

  The first light shielding member 8 includes two tooth portions 8a and 8b and a bent attachment portion 8c. The tooth portion 8a meshes with the gear 5, and the attachment portion 8c It is inserted into the long hole 1a and protrudes to the surface side of the main plate 1. And the metal 1st light-shielding plate 16 is attached to the attaching part 8c with the two screws 14 and 15. FIG. Further, the second light shielding member 9 is formed with a tooth portion 9a formed with the same radius as the tooth portion 8b and a bent mounting portion 9b. The tooth portion 9a is a tooth portion of the first light shielding member 8. 8b, the attachment portion 9b is inserted into the long hole 1b and protrudes to the surface side of the main plate 1. And the metal 2nd light-shielding plate 19 is attached to the attaching part 9b with the two screws 17 and 18. FIG. The two light shielding plates 16 and 19 are not flat plates, but are composed of two segments bent along a line parallel to the axes 6 and 7, that is, a line perpendicular to the ground plane. The surface has a mirror finish.

  Next, the operation of this embodiment will be described. FIGS. 1 and 2 show a state where the two light shielding plates 16 and 19 are not entered into the optical path. In order to limit the amount of light from this state, the motor 4 is energized and the output shaft 5 is rotated clockwise in FIG. Accordingly, the first light shielding member 8 is rotated counterclockwise by the gear 5, and the second light shielding member 9 is rotated clockwise by the first light shielding member 8. Therefore, the two light shielding plates 16 and 19 enter the optical path from opposite directions and are stopped at a predetermined position, thereby limiting the amount of passing light to a desired amount. When it is desired to further reduce the amount of light passing through, the output shaft is further rotated clockwise, and when it is desired to be increased, it is adjusted by rotating it counterclockwise.

  Further, in this embodiment, when the image or the character is not projected, the two light shielding plates 16 and 19 can block the optical path by overlapping their tips, and are in the closed state. Is shown in FIGS. 3 and 4. As can be seen from FIG. 3, in the present embodiment, the linear distance from the center line of the shaft 6, which is the rotation axis of the light shielding member 8, to the tip of the first light shielding plate 16 entering the optical path is It is shorter than the linear distance from the center line of the shaft 7 which is the rotation axis to the tip of the second light shielding plate 19 entering the optical path. Therefore, even if the two light shielding members 8 and 9 are rotated at the same speed in opposite directions at the same time, the front ends of the light shielding plates 16 and 19 integral with them can be overlapped with each other. It is possible. Therefore, according to the present embodiment, when an image or a character is not projected, an unsightly image in the ready state is not projected, and in the case of a liquid crystal projector, the performance of the liquid crystal panel is deteriorated. It can prevent suitably.

  However, the present invention is not limited to such a configuration. As in the present embodiment, the tips of the two light shielding plates 16 and 19 are not overlapped, and for example, light shielding enters the optical path from the center line of the shafts 6 and 7 that are the rotation axes of the light shielding members 8 and 9. The linear distances to the tips of the plates 16 and 19 may be the same, and the tips may be stopped in a state where the tips are substantially in contact with each other. Further, even when the linear distance from the center line of the shafts 6 and 7 that are the rotation axes of the light shielding members 8 and 9 to the tips of the light shielding plates 16 and 19 entering the optical path is the same, for example, If the rotational speeds of the first light shielding member 8 and the second light shielding member 9 are changed, the tips of the light shielding plates 16 and 19 can be overlapped as in the present embodiment. In that case, the light shielding members 8 and 9 may be rotated by different motors, but by changing the relative positional relationship of the shafts 6 and 7 so that the radii of the tooth portion 8b and the tooth portion 9a are different, Needless to say, the same motor can be used for rotation.

  Also, as can be seen from FIG. 3, at this time, each of the two segments of the light shielding plates 16 and 19 is slanted so as to approach the light source from the outside of the optical path toward the optical axis side. All the light is reflected off the optical path and does not return to the light source lamp. Therefore, in this embodiment, the reflected light is not reflected toward the light source lamp in any state between the state of FIG. 1 and the state of FIG. Therefore, in this embodiment, since the reflected light does not return to the light source lamp in any state, the light source lamp may cause irregular reflection, or the temperature of the light source lamp may be increased to shorten the life. Absent. In addition, although the light-shielding plates 16 and 19 of a present Example have two segments, this invention is not limited to such a structure, You may be comprised by one flat form. And when comprised in that way, it cannot be overemphasized that the surface of the segment by the side of the light-shielding members 8 and 9 in the light-shielding plates 16 and 19 of a present Example is match | combined with the plane of the segment of the front end side. .

  Further, as can be seen from FIG. 3, in the case of the present embodiment, the light source light is reflected by the surface opposite to the surface on the axis 6 or 7 side of the two surfaces of the light shielding plates 16 and 19. In FIG. 3, the light shielding plate 16 reflects light upward from the optical axis to the upper left, and the light shielding plate 19 reflects light downward from the optical axis to the lower left. Yes. Therefore, the reflected light goes out of the optical path quickly. On the other hand, when the shafts 6 and 7 are on the left side of the light shielding plates 16 and 19 and the inclination of the light shielding plates 16 and 19 is opposite to that of the present embodiment, the light shielding plate 16 has the optical axis. The light shield 19 reflects the lower light from the optical axis to the upper left, and the distance until the reflected light goes out of the optical path becomes longer. . Therefore, in this embodiment, the light shielding plates 16 and 19 can be arranged closer to the light source lamp, the optical component arranged just before the light source lamp, etc., and the arrangement design of the projector is advantageous. is there. Furthermore, in the present embodiment, the light source side surfaces of the light shielding plates 16 and 19 have high reflectivity due to the mirror finish, so that the light source light is efficiently reflected and the light shielding plates 16 and 19 are light sources. It is difficult to be heated directly by light. Therefore, no adverse effect is caused on the function of the diaphragm device.

  Here, although not directly related to the present invention, in the case of the present embodiment, the reason why the light shielding plates 16 and 19 are formed of two bent segments will be described with reference to FIG. . FIG. 5 shows both when the light shielding plates 16 and 19 are in the state of FIG. 1 and when they are in the state of FIG. And the locus | trajectory of the front-end | tip of the light-shielding plates 16 and 19 and the locus | trajectory of a base end are shown with the circular-arc-shaped two-dot chain line. Therefore, the working space of the light shielding plates 16 and 19 is a space surrounded by two positions and two two-dot chain lines. On the other hand, the case where the light shielding plates 16 and 19 are made flat instead of being bent as in the present embodiment is supplemented by broken lines.

  Unlike the present embodiment, when the light shielding plates 16 and 19 are formed in a flat plate shape, the segment on the base end side in the closed state has to be as shown by the broken straight lines 16A and 19A. For this reason, when the light shielding plates 16 and 19 are retracted from the optical path, the segments on the base end side thereof are as shown by broken straight lines 16B and 19B. From this, the working space of the segment on the distal end side is exactly the same as in the present embodiment, but the working space of the segment on the proximal end side is much larger than in the case of the present embodiment, and in particular, it is indicated by hatching. As shown in FIG. 5, an optical component such as a lens or an optical path regulating frame is disposed on the right side of the light shielding plates 16 and 19 in order to require a large space in the direction along the optical axis. In this case, it must be arranged on the right side of the present embodiment. Accordingly, when the light shielding plates 16 and 19 are bent as in the present embodiment, the working space can be reduced, and the degree of freedom in designing the projector is increased.

  In this embodiment, the light shielding plates 16 and 19 are each composed of two segments. However, the light shielding plates 16 and 19 may be composed of three or more segments. In the case of the present embodiment, the light shielding members 8 and 9 and the light shielding plates 16 and 19 are separated from each other in consideration of cost and ease of manufacture. However, the light shielding members 8 and 9 and the light shielding plate 16 are separated. , 19 may be manufactured as a single metal member. Furthermore, in the case of the present embodiment, the tooth portions 8a, 8b, 9a are formed on the light shielding members 8, 9 and are rotated by the gear 5, but the light shielding member 8 is not required to have such a configuration. , 9 can be simultaneously rotated in opposite directions. For example, in this embodiment, a part of the light shielding members 8 and 9 are overlapped with each other, a pin is fitted into both elongated holes formed in the overlapping portion, and the pin is reciprocated. In the same manner as described above, the light shielding members 8 and 9 can be operated. In such a configuration, the light shielding members 8 and 9 are made of a thin metal plate material, and as described above, the light shielding members 8 and 9 and the light shielding plates 16 and 19 are produced as one metal member. In some cases, this is a preferred configuration.

It is a top view of the Example which showed the state which has a light-shielding plate out of an optical path. It is a left view of FIG. It is a top view of the Example which showed the interruption | blocking state of the optical path by a light-shielding plate. FIG. 4 is a left side view of FIG. 3. It is a top view for demonstrating the characteristic of an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground plane 1a, 1b Long hole 1c, 1d, 1e, 1f Hole 2,3,10,11,12,14,15,17,18 Screw 4 Motor 4a Output shaft 5 Gear 6, 6 Axis 8 First light shielding member 8a , 8b, 9a Tooth part 8c, 9b Mounting part 9 Second light shielding member 13 Cover plate 16 First light shielding plate 19 Second light shielding plate

Claims (4)

  Two light-shielding members that are attached to the side of the optical path of the light source light so as to be substantially parallel to the optical path, with the axes that are parallel to each other as rotation axes, can be simultaneously rotated in different directions. Thus, the light shielding plate portions provided in them are advanced and retracted from the opposite directions into the optical path to adjust the light amount of the light source light, and the light shielding plate portion transmits the light source light to the light source side optical path in the optical path. An aperture device for a projector, characterized in that it is configured to reflect outside, and the two light shielding plates can block the light path while reflecting the light source light outside the light path.   2. The two light shielding members are arranged so as to reflect light source light to an outside of an optical path on a surface of the light shielding plate portion opposite to the rotation axis side. Projector aperture device.   The two light shielding members are rotated by a single drive source, and the linear distances from the rotating shaft to the entry end of the light shielding plate portion are different from each other, and in a state where the light path is blocked, both 3. The aperture device for a projector according to claim 1, wherein the intrusion end of the projector overlaps the optical axis. 4. The projector diaphragm device according to claim 1, wherein the light shielding plate portion is formed so that a surface on a light source side has a high reflectance.