JP2008145949A - Diaphragm apparatus for projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm device that makes two driving members rotate in opposing directions, and controls a diaphragm aperture by relatively operating two shielding means of lights, the device operating the two shielding means of lights with stability, even if two members made of synthetic resin, in which both the gear parts mesh with each other, are expanded thermally. <P>SOLUTION: A first drive member 9 made of the synthetic resin has a first light-shielding plate 18 attached thereto and is rotated by a motor 6, wherein the first drive member 9 is installed rotatably on a shaft member 8 fixed to a bottom board 1. A second drive member 15 made of a synthetic resin has a second light-shielding plate 19 attached thereto and is rotated by the first drive member 9, in a direction opposite to the rotating direction of the first drive member, wherein the second drive member 15 is installed rotatably in a shaft member 14 that can make the interval with the shaft member change 8. A coiled spring 17 urges the second drive member 15, while pressing a gear 15c of the second drive member 15 against a gear 9c of the first drive member 9. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  Recently, liquid crystal projectors equipped with a liquid crystal panel and DMD projectors equipped with a DMD (digital micromirror device) have emerged, and are used for business presentations and various lectures and presentations. In addition, it is also used as equipment for home theater. Especially in the case of a liquid crystal projector, if the illumination light quantity from the light source lamp that hits the liquid crystal panel is not projected, if the aperture is temporarily weakened or not applied at all, the liquid crystal panel will deteriorate. It is known that can be prevented.

  Further, in Patent Document 1 below, in such a projector, the illumination light amount from the light source lamp is changed corresponding to the brightness of the room to be projected, or illumination light is temporarily emitted when nothing is projected. In order to make it weaker, instead of changing the amount of light emitted from the light source lamp itself, an aperture device configured to rotate the two light shielding members like a double door in the vicinity of the light source lamp is arranged, and the light source light The optical path area is changed. It is also described that it is possible to obtain a high-contrast image by arranging the aperture device in this way.

  Further, in Patent Document 2 below, in an overhead projector using a variable magnification optical system as a projection optical system, two L-shaped frame members are squared between a stage for placing a document and a light source. There is described a diaphragm device arranged so as to be relatively slid along the diagonal line of the optical path opening to change the optical path area. It is also described that a projection image at a high magnification can be suitably obtained by arranging the aperture device in such a manner.

  Patent Document 3 below describes an aperture device that can be used in the above-described liquid crystal projector, DMD projector, overhead projector, and the like. The diaphragm device includes two diaphragm blades each composed of two arms and two blade members pivotally supported on both arms, and the diaphragm blades are formed into a rectangular optical path. It is configured to slide relative to the opening to change the size of the optical path.

  The various aperture devices as described above are operated by various drive mechanisms. However, in Patent Document 1, when one of the two light shielding members is operated by rotating a motor, the other light shielding member is a gear. A throttling device is described which is relatively actuated through a mechanism. Patent Document 3 also describes a diaphragm device in which when one of the two diaphragm blades is operated by rotating a motor, the other diaphragm blade is relatively operated via a gear mechanism. ing. When such a configuration is adopted, only one motor is required as the driving means, which is advantageous in terms of cost, and the relative operation of the two light shielding means can be stably obtained. There is. The present invention relates to a diaphragm device for various projectors in which two light shielding means are relatively operated by one driving means through a gear mechanism.

JP 2004-69966 A JP-A-8-227102 JP 2005-157162 A

  As described above, when the member constituting the gear mechanism is made of metal, the diaphragm device configured to relatively actuate the two light shielding means with one driving means via the gear mechanism, the gear portion Since the sound is generated by the meshing, the operating sound becomes very worrisome during projection in a quiet room. Therefore, conventionally, a member having a gear portion is usually made of a synthetic resin. However, as is well known, the interior of the projector becomes very hot due to heat generated by a light source lamp or the like. For this reason, if such an aperture device is disposed at a position where the temperature is extremely high, such as a position near the light source lamp, these members will thermally expand, resulting in less backlash, resulting in unstable or non-operational operation. was there.

  The present invention has been made to solve such problems. The object of the present invention is to rotate two drive members in opposite directions by means of a drive mechanism and a gear mechanism. In the diaphragm device in which the two light-shielding means are relatively operated by these drive members and the diaphragm opening is controlled, the two members made of synthetic resin meshing each other's gear portions, It is an object of the present invention to provide a projector diaphragm device in which two light-shielding means can stably operate relatively even if they thermally expand due to the temperature in the projector.

  In order to achieve the above object, a projector diaphragm device according to the present invention is made of a synthetic resin that has a gear portion on an outer peripheral portion thereof and is rotatably attached to a base plate and is reciprocally rotated by a driving means. A first driving member; a first light-shielding means that is advanced and retracted in a central direction of the optical path by rotation of the first driving member; and a gear portion that meshes with a gear portion of the first driving member on an outer peripheral portion. A rotation axis substantially parallel to the rotation axis of the first drive member is attached to the main plate so that the distance from the rotation axis of the first drive member can be changed, and the first drive member rotates to rotate the first drive member. A second drive member made of synthetic resin that is rotated in a direction opposite to that of the first drive member, and the first light shielding means is operated relatively by rotation of the second drive member and is opposite to the first light shielding means. The light path from the direction A second light-shielding means that is advanced and retracted toward the central direction and controls the amount of light passing in cooperation with the first light-shielding means; and the rotational axis of the second drive member is urged in the direction of the rotational axis of the first drive member And an urging means that presses the gear portion of the second drive member against the gear portion of the first drive member.

  In order to achieve the above-mentioned object, the projector diaphragm device of the present invention has a gear portion on the outer peripheral portion, is rotatably attached to the base plate, and is a synthetic resin that is reciprocally rotated by a driving means. A first driving member made of metal, a first light-shielding means that moves forward and backward in the center of the optical path by rotation of the first driving member, and a rotating shaft that is attached to the base plate in parallel with the rotating shaft of the first driving member A second drive member, and a gear portion that meshes with the gear portion of the first drive member, and is attached to the outer peripheral portion of the second drive member so as to be movable only in the radial direction of the second drive member. A segment member made of synthetic resin that allows the second drive member to rotate in a direction opposite to the first drive member by the rotation of the first drive member, and the rotation of the second drive member causes the A second light-shielding means that is operated relative to the first light-shielding means and is advanced or retracted from the opposite direction to the center of the optical path from the opposite direction to the first light-shielding means, and controls the amount of light passing through the first light-shielding means. And a biasing means that biases the segment member in the radial direction of the second drive member and presses the gear portion of the segment member against the gear portion of the first drive member. .

  In these cases, the first light-shielding means and the second light-shielding means have the plate surfaces parallel to the rotation axis of the first drive member and the rotation axis of the second drive member. Two arms may be fixed to the member and the second driving member, and each of the first light shielding means and the second light shielding means is rotatably attached to the ground plane. And at least one blade member pivotally supported by both of the arms, and one of the arms may be connected to the first drive member or the second drive member. .

  The present invention relates to a diaphragm device in which two driving members are rotated in opposite directions by one driving means via a gear mechanism, and the diaphragm opening is controlled by relatively operating two light shielding means. Since the gear part formed on the other member is pressed by the biasing means against the gear part formed on one member of the two members made of synthetic resin, Even if those members are thermally expanded, when one member is rotated, it becomes possible to rotate while moving the other member in a direction away from one member against the urging force of the urging means. There is an advantage that the two light shielding means can be operated relatively stably.

  The best mode for carrying out the present invention will be described with reference to two illustrated embodiments. Each of these embodiments is configured as a diaphragm device of the type described in Patent Document 1. However, the present invention can also be configured as an aperture device in which the two light shielding means are relatively operated on substantially the same plane, like the aperture device of the type described in Patent Document 3. is there. 1 to 4 are for explaining the first embodiment, and FIGS. 5 and 6 are for explaining the second embodiment.

  First, the configuration of this embodiment will be described. 1 is a perspective view showing the cover plate shown in FIG. 2 and its mounting structure omitted, and FIG. 2 is a plan view seen from above in FIG. 3 is an enlarged plan view of the main part of FIG. 2 and shows the cover plate with a two-dot chain line, and FIG. 4 is a cross-sectional view taken along line AA of FIG. The base plate 1 of the present embodiment is made of metal, and has two large elongated holes 1a and 1b formed symmetrically, four holes 1c, 1d, 1e and 1f formed in a circle, and two small holes It has long holes 1g and 1h and a recess 1i formed in a circular shape. Of these, four circular holes 1c, 1d, 1e, and 1f are holes for attachment to the projector body. Further, the long hole 1g is not marked in FIG. 1 because it is difficult to see, and is easy to understand in FIGS.

  In FIG. 2, two pillars 2 and 3 are erected on the upper left position of the main plate 1, and a motor 6 is attached to the top surface of the pillars 2 by two screws 4 and 5. This motor 6 is a step motor, and a synthetic resin gear 7 is attached to the tip of its output shaft, as shown in FIG. A synthetic resin first drive member 9 is rotatably attached to a metal shaft member 8 erected on the main plate 1. The first drive member 9 has a plate shape, and has a cylindrical portion 9a fitted to the shaft member 8 at a substantially central portion, and an attachment portion 9b and two gear portions 9c on the outer peripheral portion. , 9d. Of these, the gear portion 9 d shown in a simplified manner meshes with the gear 7. Further, as shown in FIG. 1, a ring-shaped protrusion 9a-1 is formed on the distal end surface of the cylindrical portion 9a.

  A cover plate 10 is attached to the ground plate 1 with three screws 11, 12, 13 at a predetermined interval from the ground plate 1. The cover plate 10 is shown with a reference numeral in FIGS. 3 and 4 in addition to a circular hole (not indicated) in which a small diameter portion formed at the tip of the shaft member 8 is fitted. It has a long hole 10a. And in the attachment state of this cover board 10, the ring-shaped protrusion 9a-1 formed in the cylinder part 9a of the 1st drive member 9 comes into sliding contact. In FIG. 1, the cover plate 10 and its mounting structure are not shown. In FIG. 3, the cover plate 10, the long hole 10 a, and the screw 12 are indicated by a two-dot chain line. .

  The metal shaft member 14 disposed so as to be parallel to the shaft member 8 between the base plate 1 and the cover plate 10 forms a shaft portion 14a as shown in FIG. And the parts forming the retaining portion 14b are screwed together, guided by the long hole 1g of the base plate 1 and the long hole 10a of the cover plate 10, It is attached to the main plate 1 so that the distance can be changed. Further, the shaft member 8 is not specifically shown in configuration, but is substantially configured in the same manner as the shaft member 14, and the difference between them is not fixed to the main plate 1. That is the difference. The second drive member 15 made of synthetic resin is rotatably attached to the shaft member 14, and the second drive member 15 has a plate shape and has a shaft at a substantially central portion. It has a cylinder part 15 a to be fitted to the member 14, and has an attachment part 15 b and a gear part 15 c that meshes with the gear part 9 c of the first drive member 9 on the outer peripheral part. Further, a ring-shaped protrusion 15 a-1 is formed on the distal end surface of the cylindrical portion 15 so as to be in sliding contact with the cover plate 10.

  In the recess 1 i of the base plate 1, a metal shaft member 16 having a tip formed in a flange shape is erected. A coil spring 17 is wound around the shaft member 16. One end of the shaft member 16 is hooked on the long hole 1 h of the base plate 1, and the other end is hooked on the cylindrical portion 15 a of the second drive member 15. Is indirectly biased toward the shaft member 8, and the gear portion 15 c of the second drive member 15 is elastically pressed against the gear portion 9 c of the first drive member 9. In the case of the present embodiment, it is configured as described above. Instead of providing the coil spring 17, for example, the distal ends of the shaft member 8 and the shaft member 14 are lengthened, and a tension spring is provided between them. Even if it is applied, the same effect as in the present embodiment can be obtained.

  As shown in FIG. 1, a first light shielding plate 18 and a second light shielding plate 19 are disposed on the side opposite to the first drive member 9 and the second drive member 15 with the ground plate 1 in between. . And some of them penetrate the long holes 1a, 1b of the main plate 1, and two screws 20, 21 with respect to the mounting portion 9b of the first drive member 9 and the mounting portion 15b of the second mounting portion 15, respectively. , 22, 23. Therefore, the first light shielding plate 18 and the second light shielding plate 19 have their plate surfaces parallel to the rotation axis of the first drive member 9 and the rotation axis of the second drive member 15, that is, The first drive member 9 and the second drive member 15 are attached so as to be perpendicular to the plate surfaces. The first light shielding plate 18 and the second light shielding plate 19 are formed with notches 18a and 19a for forming a small opening in cooperation.

  Next, the operation of this embodiment will be described. In the present embodiment, the light travels from the lower left direction toward the upper right direction in FIG. Therefore, in FIG. 2, light travels from the bottom to the top. Further, the cross-sectional shape of the optical path reaching the position of the light shielding plates 18 and 19 is restricted by another configuration not shown, but the cross-sectional shape of the optical path passing through the position of the light shielding plates 18 and 19, that is, the maximum aperture aperture. The shape is substantially square, and is only slightly smaller than the combined area of the two light shielding plates 18 and 19. Therefore, in order to make it possible to understand the size, in FIG. 2, the positions of both ends of the optical path width are indicated by two parallel two-dot chain lines with arrows.

  1 and 2, the two light shielding plates 18 and 19 are close to one end of the long holes 1a and 1b of the base plate 1 at the center of the optical path, and are closest to each other. Therefore, the minimum diaphragm aperture that allows light only in the vicinity of the center of the optical path to pass is controlled by the cooperation of the notches 18a and 19a. In this embodiment, the optical path is not completely closed as described above. However, when an image or a character is not projected, or in the case of a liquid crystal projector, the optical path is completely closed due to reasons such as preventing the deterioration of the performance of the liquid crystal panel more preferably than in the case of this embodiment. In order to achieve this, the cutout portions 18a and 19a need not be formed in the two light shielding plates 18 and 19.

  In the state of FIG. 1 and FIG. 2, when it is desired to increase the amount of light passing through, the motor 6 is energized and its output shaft is rotated counterclockwise in FIG. Accordingly, the first drive member 9 is rotated clockwise by the gear 7, and the second drive member 15 is rotated counterclockwise by the first drive member 9. Therefore, the two light shielding plates 18 and 19 are moved relative to each other and retracted in the direction outside the optical path, stopped at a predetermined position, and controlled to pass a desired amount of light. Further, from this state, when it is desired to increase the amount of light passing through, the output shaft of the motor 6 is further rotated counterclockwise to move the two light shielding plates 18 and 19 to the outside of the optical path. The two light shielding plates 18 and 19 are rotated to move toward the center of the optical path. And when the 1st light-shielding plate 18 stops in the proximity position of the left end of the elongate hole 1a, and the 2nd light-shielding plate 19 stops in the position near the right end of the elongate hole 1b, it will be the control state of the largest aperture opening. .

  In the case of the present embodiment, since the two drive members 9 and 15 are made of synthetic resin, the operating noise generated between the gear portions 9c and 15c is suppressed to the minimum regardless of the operation. It has come to be. However, even if the two drive members 9 and 15 are simply made of heat-resistant synthetic resin as in the prior art, the temperature environment due to heat generation of electrical components such as light source lamps and heat generation of the members irradiated with light, etc. Due to the influence, the two drive members 9 and 15 may be thermally expanded, so that the backlash between the gear portions 9c and 15c is reduced, and the two drive members 9 and 15 are not smoothly rotated. In some cases, such a problem does not occur in the present embodiment.

  The reason is that the shaft member 14 serving as the rotation shaft of the second drive member 15 is movable and the distance from the shaft member 8 serving as the rotation shaft of the first drive member 9 can be changed. is there. Therefore, even if the backlash between the gear portions 9c and 15c is reduced due to thermal expansion, the first drive member 9 has the second drive against the biasing force of the coil spring 17 by the gear portion 9c pushing the gear portion 15c. Since the member 15 is rotated together with the shaft member 14 in a direction away from the first drive member 9, it can be smoothly rotated in the same manner as when a predetermined backlash is obtained. Further, when the heat shrinks thereafter, the second drive member 15 together with the shaft member 14 comes closer to the first drive member 9 due to the urging force of the coil spring 17, so that smooth smoothness is obtained in the same manner as the predetermined backlash is obtained. Can be rotated.

  In this embodiment, when the first drive member 9 is thermally expanded, a situation similar to the meshing relationship between the other gear portion 9d and the gear 7 occurs. However, since the gear portion 9c has a larger distance to the shaft member 8 than the gear portion 9d, the gear portion 9c is usually larger in deformation due to thermal expansion. In addition, since the gear portion 9c meshes with the gear portion 15c of the second drive member 15 that is deformed to the same extent, at the meshing position between the gear portion 9c and the gear portion 15c, the influence of expansion is doubled. Become. In comparison, the change in the gear portion 9d is small for the above-described reason, and the influence of thermal expansion can be ignored. In the present embodiment, there is no change in the meshing relationship between the gear portion 9d and the gear 7. No measures are taken. This can be said even if the gear 7 is made of metal. However, if the influence of thermal expansion cannot be ignored, the first drive member 9 may be directly rotated by the output shaft of the motor 6.

  Next, Embodiment 2 will be described. FIG. 5 is a plan view of the present embodiment shown in the same manner as FIG. 2, and FIG. 6 is a schematic diagram of the present embodiment shown in FIG. It is the top view which expanded and showed the part. As can be seen by comparing FIG. 5 showing the present embodiment with FIG. 2 described above, the configuration of the present embodiment is substantially the same as the configuration of the first embodiment. In FIG. 2, the same reference numerals are given to substantially the same members and parts as those in the first embodiment. Therefore, in the following, only points different from the case of the first embodiment will be described in order to avoid duplication.

  The base plate 1 of the present embodiment is substantially the same as that of the first embodiment, but has two small long holes 1g and 1h formed in the first embodiment and a recess 1i formed in a circular shape. Not done. Therefore, in the case of the present embodiment, the shaft member 16 is not erected and the coil spring 17 is not provided. In the present embodiment, the shaft member 24 having the same configuration as the shaft member 8 to which the first drive member 9 is rotatably attached is erected on the main plate 1 in the same manner as the shaft member 8. Yes. And the 2nd drive member 15 of a present Example attached rotatably with respect to the shaft member 24 is a product made from a synthetic resin like the 2nd drive member 15 in Example 1, and is the completely same shape. Although it has the cylinder part 15a and the attachment part 15b, it does not have the gear part 15c in Example 1. FIG.

  As shown in FIG. 6, the second drive member 15 of the present embodiment has two holes 15d and 15e formed on the outer peripheral surface thereof. Further, in the case of the present embodiment, a synthetic resin arc-shaped segment member 25 is provided, and a gear portion 25 a that meshes with the gear portion 9 c of the first drive member 9 is formed on the outer peripheral portion thereof. In addition, two shaft portions 25b and 25c to be inserted into the holes 15d and 15e of the second drive member 15 are provided on the inner peripheral portion. Further, compression springs 26 and 27 are fitted on the shaft portions 25b and 25c, respectively, and the segment member 25 is urged in a direction in which the shaft portions 25b and 25c come out of the holes 15d and 15e. The segment member 25 is assembled in such a state that the shaft portions 25b and 25c of the segment member 25 are pushed deeply into the holes 15d and 15e against the urging force of the compression springs 26 and 27, and the gear portions 9c and 25a are connected to each other. Are aligned in a predetermined facing relationship, and then the pressing force is released. Therefore, in the meshed state, the gear portion 25a is pressed against the gear portion 9c by the urging force of the compression springs 26 and 27. Other configurations are the same as those in the first embodiment. Needless to say, in this embodiment, the second drive member 15 may be made of metal.

  In this embodiment, since the first drive member 9 and the segment member 25 are made of synthetic resin as described above, the operation sound generated between the gear portions 9c and 25a is suppressed to the minimum. Even if the first drive member 9 and the segment member 25 are thermally expanded, the first drive member 9 has the gear portion 9c that presses the gear portion 25a, and the shaft portions 25b and 25c of the segment member 25 are Since the second drive member 15 is rotated so as to be pushed deeper than usual into the holes 15d and 15e against the urging force of 27, the two drive members 9 and 15 rotate smoothly, and a desired aperture opening is suitable. It becomes possible to control. The control operation of the aperture opening is performed in the same manner as in the first embodiment, and thus the description thereof is omitted. In the description of the first embodiment, what has been described about the configuration common to the present embodiment also applies to the present embodiment.

It is a perspective view of Example 1 which abbreviate | omitted and showed the cover board shown by FIG. 2 and its attachment structure. 1 is a plan view of Example 1. FIG. It is the top view which expanded the principal part of FIG. 2 and showed the cover board with the dashed-two dotted line. FIG. 4 is a cross-sectional view taken along line AA in FIG. 3. 6 is a plan view of Example 2. FIG. It is the top view which expanded and showed the principal part of FIG.

Explanation of symbols

1 Ground plate 1a, 1b, 1g, 1h, 10a Long hole 1c, 1d, 1e, 1f, 15d, 15e Hole 1i Recess 2, 3 Pillar 4, 5, 11, 12, 13, 20, 21, 22, 23 Screw 6 Motor 7 Gear 8, 14, 16, 24 Shaft member 9 First drive member 9a, 15a Tube portion 9a-1, 15a-1 Projection 9b, 15b Mounting portion 9c, 9d, 15c, 25a Gear portion 10 Cover plate 14a, 25b, 25c Shaft portion 14b Retaining portion 15 Second driving member 17 Coil spring 18 First light shielding plate 19 Second light shielding plate 18a, 19a Notch portion 25 Segment member 26, 27 Compression spring

Claims (4)

  A first drive member made of synthetic resin having a gear portion on the outer peripheral portion and rotatably attached to the base plate and reciprocally rotated by a drive means, and a central direction of the optical path by the rotation of the first drive member A first light-shielding means that is moved forward and backward, and a gear portion that meshes with a gear portion of the first drive member on an outer peripheral portion, and a rotation axis that is substantially parallel to the rotation axis of the first drive member A second drive made of synthetic resin, which is attached to the main plate so as to change the distance from the rotation shaft of the drive member, and is rotated in the opposite direction to the first drive member by the rotation of the first drive member. The rotation of the second drive member and the member is operated relative to the first light shielding means, and is advanced and retracted from the opposite direction to the center of the optical path from the direction opposite to the first light shielding means. To control the amount of light passing through The second light shielding means and the rotation shaft of the second drive member are urged in the direction of the rotation shaft of the first drive member, and the gear portion of the second drive member is pressed against the gear portion of the first drive member. And a biasing means.   A first drive member made of synthetic resin having a gear portion on the outer peripheral portion and rotatably attached to the base plate and reciprocally rotated by a drive means, and a central direction of the optical path by the rotation of the first drive member A first light shielding means that is moved forward and backward, a second drive member that is attached to the main plate with a rotation shaft parallel to the rotation shaft of the first drive member, and a gear that meshes with a gear portion of the first drive member And is attached to an outer peripheral portion of the second drive member so as to be movable only in a radial direction of the second drive member, and the second drive member is driven by the rotation of the first drive member. A segment member made of synthetic resin that is rotated in a direction opposite to the member, and the first light shielding unit is operated relative to the first light shielding unit by the rotation of the second driving member. Opposite direction A second light-shielding unit that is advanced and retracted in the central direction of the optical path and controls the amount of light passing in cooperation with the first light-shielding unit; and the segment member is urged in the radial direction of the second drive member. And a biasing means that presses the gear portion against the gear portion of the first drive member.   The first light-shielding means and the second light-shielding means are configured such that the plate surface is parallel to the rotation axis of the first drive member and the rotation axis of the second drive member. The projector diaphragm device according to claim 1, wherein the diaphragm device is fixed to a member.   Each of the first light-shielding means and the second light-shielding means is composed of two arms rotatably attached to the main plate and at least one blade member pivotally supported by both the arms. 3. The diaphragm device for a projector according to claim 1, wherein one of the arms is connected to the first drive member or the second drive member.

Images