JP2018036365A - Optical unit with dust-proof function and projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical unit with a dust-proof function, in which a sufficient dust-proof effect can be obtained.SOLUTION: The optical unit includes an image forming device 2, a lens mount 4 where a projection lens 3 is joined, a box 10 housing the image forming device 2 and the lens mount 4, and a cylindrical elastic member 5 opened at both ends. The box 10 has an opening 10b on a side face 10a opposing to the lens mount 4. One open end 5a of the elastic member 5 is joined to the opening 10b, while the other open end 5b is joined to the lens mount 4. The joined part between the open end 5a and the opening 10b has a labyrinth seal structure. The labyrinth seal structure has a groove 10c formed to enclose the opening 10b and a projection 5c to be fitted to the groove 10c.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to an optical unit with a dustproof function and a projector.

The projector includes a light source, an image forming device that forms an image by modulating light flux from the light source, and a projection lens that projects an image formed on the image forming device. The image forming device is, for example, a DMD (digital mirror device) or a liquid crystal panel. Optical components such as a mirror, a lens, and a prism are appropriately arranged in the optical path between the light source and the image forming device and in the optical path between the image forming device and the projection lens. In such a projector, when dust or dirt adheres to an image forming device or an optical component, luminance and image quality may be deteriorated.
Accordingly, a projector with a dustproof function in which an image forming device or the like is housed in a dustproof case has been proposed (see Patent Document 1). A lens mount to which the projection lens is cemented is housed in the dustproof case. The dustproof case includes an opening on a side surface facing the lens mount. Through this opening, the projection lens can be joined to the lens mount in the dustproof case.

Between the opening of the dustproof case and the lens mount, a cylindrical seal member having both ends opened is provided. One open end of the seal member is fixed to the opening of the dustproof case, and the other open end is fixed to the lens mount.
An annular belt is often used for fixing the opening end of the seal member. For example, a side wall is formed in the opening of the dustproof case so as to surround the opening, and the opening end of the seal member is sandwiched between the side wall and the belt.

JP 2016-133609 A

  However, in a structure in which the opening end of the seal member is fixed using an annular belt, a sufficient dustproof effect may not be obtained depending on the opening shape. For example, when the opening has a shape having a straight part such as a square, the side wall usually has a straight part. In the straight part of the side wall, the pressure for pressing the opening end of the seal member against the side wall with the belt decreases, and as a result, a sufficient dustproof effect cannot be obtained.

  An object of the present invention is to provide an optical unit with a dustproof function and a projector capable of obtaining a sufficient dustproof effect.

In order to achieve the above object, according to one aspect of the present invention,
An image forming device for forming an image;
A lens mount to which a projection lens for projecting the image is joined;
A box containing the image forming device and the lens mount;
A cylindrical elastic member having both ends opened,
The box includes a first opening on a side surface facing the lens mount,
Of the openings at both ends of the elastic member, one opening end is joined to the first opening, and the other opening end is joined to the lens mount,
A joint portion between the one opening end and the first opening portion has a labyrinth seal structure, and the labyrinth seal structure includes a first groove portion formed so as to surround the first opening portion, and the first groove portion. There is provided an optical unit with a dustproof function, which has a first convex portion fitted into one groove portion.

According to another aspect of the invention,
The above dust-proof optical unit;
A projection lens for projecting an image formed by the image forming device,
A projector is provided in which the projection lens is joined to the lens mount of the optical unit.

  ADVANTAGE OF THE INVENTION According to this invention, the optical unit with a dustproof function which can acquire a dustproof effect can be provided irrespective of opening shape.

It is a schematic diagram which shows the structure of the principal part of the optical unit with a dustproof function by one Embodiment of this invention. It is a front view of the seal part of the optical unit shown in FIG. It is a disassembled perspective view of the principal part of the optical unit by the 2nd Embodiment of this invention. It is a schematic diagram which shows the seal | sticker part of the optical unit shown in FIG. It is a perspective view which shows the assembly for electrically conductive cloth fixation typically. It is a disassembled perspective view of the assembly for electrically conductive cloth fixation. It is a schematic diagram which shows a 1st deviation prevention structure. It is a schematic diagram which shows the 2nd shift prevention structure. It is a schematic diagram which shows the 3rd deviation prevention structure. It is a block diagram which shows one Embodiment of the projector of this invention.

Next, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1A is a schematic diagram illustrating a configuration of a main part of an optical unit with a dustproof function according to an embodiment of the present invention. FIG. 1B is a front view of a seal portion of the optical unit.
Referring to FIGS. 1A and 1B, the optical unit 1 includes an image forming device 2, a lens mount 4 to which the projection lens 3 is joined, a box 10 for housing the image forming device 1 and the lens mount 4, and both ends. And an open cylindrical elastic member 5. The image forming device 2 forms an image by spatially modulating light from a light source (not shown). As the image forming device 2, a display element such as a DMD or a liquid crystal panel can be used. Although not shown in FIG. 1, optical components such as a light source, a mirror, a lens, and a prism are appropriately arranged inside the box 10. Although only one image forming device 2 is shown, two or more image forming devices 2 may be provided.

The box 10 includes an opening 10b on a side surface 10a facing the lens mount 4. The opening 10b includes a rounded quadrangular (rounded quadrangular) opening. Of the openings at both ends of the elastic member 5, one opening end 5 a is joined to the opening 10 b and the other opening end 5 b is joined to the lens mount 4. The opening shape of the opening end 5 a is the same as the opening shape of the opening 10 b, and the opening shape of the opening end 5 b is the same as the outer shape of the lens support portion of the lens mount 4.
The joint between the opening end 5a and the opening 10b has a labyrinth seal structure. The labyrinth seal structure includes a groove portion 10c formed so as to surround the opening portion 10b, and a convex portion 5c fitted into the groove portion 10c. The elastic member 5 includes an annular contact surface that is in contact with the side surface 10a of the box 10 at the opening end 5a, and a convex portion 5c is formed on the contact surface. The groove portion 10 c is formed on the side surface 10 a of the box 10. The pressing member 6 fixes the opening end 5a to the opening 10b in a state where the protrusion 5c is fitted in the groove 10c. A fixing means such as a screw can be used to fix the presser member 6.

The convex portion 5 c may be formed on the side surface 10 a of the box 10, and the groove portion 10 c may be formed on the contact surface of the elastic member 5. Moreover, although the number of the groove part 10c and the convex part 5c is each one, it is not limited to this. Two or more grooves 10c and two protrusions 5c may be provided.
The joint between the open end 5b and the lens mount 4 may have a labyrinth seal structure or a structure using an annular belt. Since the outer shape of the joint portion of the lens mount 4 is circular, a sufficient dustproof effect can be obtained even if an annular belt is used.
The lens mount 4 may be configured to be movable in the optical axis direction of the projection lens 3 and in a direction orthogonal to the optical axis direction. For example, the lens mount 4 may be fixed on a stage that can move in directions of three axes (XYZ) orthogonal to each other.

According to the optical unit 1 of the present embodiment, the following operational effects are obtained.
In the present embodiment, even in the linear portion of the groove 10c, the groove 10c and the protrusion 5c can be reliably fitted, and a sufficient dustproof effect can be obtained.

When the opening end 5a of the elastic member 5 is fixed to the opening 10b of the box 10 using an annular belt without using the labyrinth seal structure, usually, the opening is surrounded along the edge of the opening 10b. Side walls are provided. The opening end 5a is fixed to the opening 10b by fitting the side wall into the opening end 5a of the elastic member 5 and sandwiching the opening end 5a between the annular belt and the side wall. In such a fixing structure using an annular belt, a sufficient dustproof effect may not be obtained depending on the opening shape of the opening 10b. For example, when the opening has a shape having a straight part such as a quadrangle, the side wall also usually has a straight part. In the linear part of the side wall, the pressure for pressing the open end 5a of the elastic member 5 against the side wall with the belt decreases, so that a sufficient dustproof effect cannot be obtained.
In addition, by forming the side wall in a circular shape, the open end 5a can be pressed against the side wall with a uniform pressure over the entire circumference. However, in this case, since the outer shape (circular shape) of the side wall becomes large, it is necessary to enlarge the opening end 5a of the elastic member 5, and as a result, the elastic member 5 becomes large and costs increase.

On the other hand, in this embodiment, by using the labyrinth seal structure, a sufficient dustproof effect can be obtained over the entire circumference of the opening 10b regardless of the opening shape.
In addition, it is possible to accurately position the opening end 5a of the elastic member 5 with respect to the opening 10b of the box 10 by fitting the protrusion 5c into the groove 10c. It is difficult to perform such positioning with a fixing structure using an annular belt.

(Second Embodiment)
FIG. 2 is an exploded perspective view of the main part of the optical unit according to the second embodiment of the present invention. FIG. 3 is a schematic diagram illustrating a seal portion of the optical unit. Part (a) is a perspective view of a cut part obtained by cutting the seal part of the optical unit along the optical axis, and part (b) is an enlarged view of a part of the cut part.

2 and 3, the optical unit includes a box 20 including an upper case 20-1 and a lower case 20-2. The box 20 accommodates the lens mount 14 to which the projection lens is bonded, and includes an opening 20b on the side surface 20a facing the lens mount 14. The opening 20b includes a rounded quadrangular opening. Although not shown, the light source, the image forming device, the mirror, the lens, the prism, and the like as described in the first embodiment are appropriately arranged in the box 20.
As a seal member between the lens mount 14 and the opening 20b of the box 20, a rubber boot 15 that is an elastic member having both ends opened is provided. Of the openings at both ends of the rubber boot 15, one opening end 15 a is joined to the opening 20 b and the other opening end 15 b is joined to the lens mount 14. The opening shape of the opening end 15a is the same as the opening shape of the opening 20b.

  The lens mount 14 is configured to be movable in the optical axis direction of the projection lens and in a direction orthogonal to the optical axis direction, specifically, in directions of three axes (XYZ) orthogonal to each other. The lens mount 14 includes a circular support portion 14a that supports the cemented surface of the projection lens, and an annular side wall 14b that is formed so as to surround the outer periphery of the support portion 14a. With the side wall 14b fitted into the open end 15b of the rubber boot 15, the fixing bands 11-1 and 11-2 fix the open end 15b to the side wall 14b. The upper part of the opening end 15b is sandwiched between the fixing band 11-1 and the side wall 14b on the upper case 20-1, and the opening is formed between the fixing band 11-2 and the side wall 14b on the lower case 20-2 side. The lower part of the end 15b is sandwiched. For example, rubber or resin can be used for the fixing bands 11-1 and 11-2, but is not limited thereto.

  The open end 15a of the rubber boot 15 includes an annular contact surface that is in contact with the side surface 20a of the box 20, and a convex portion 15c is formed on the contact surface. An annular groove 20c is formed in the portion of the side surface 20a where the opening 20b is formed. With the convex portion 15c fitted in the groove portion 20c, the opening end 15a is fixed to the opening portion 20b using the presser metal plate 16. The presser metal plate 16 is provided with a through hole, and the presser metal plate 16 is fixed by screwing the screw 16a into the screw hole provided in the side surface 20a through the through hole. A plurality of fixing portions using the screws 16a are provided. A portion composed of the convex portion 15c and the groove portion 20c is a portion of the labyrinth seal structure. In addition, although the number of the groove parts 20c and the convex parts 15c is each one, it is not limited to this. You may provide two or more each of the groove part 20c and the convex part 15c.

Also in this embodiment, the rubber boot 15 provided between the lens mount 14 and the opening 20b of the box 20 can provide the same dustproof effect as that of the first embodiment.
In this embodiment, in addition to the dust-proof effect, a cylindrical conductive cloth 17 having conductivity opened at both ends is provided for EMI (Electro-Magnetic Interference) countermeasures.

Inside the projector including the box 20, a noise source such as a substrate is accommodated. The noise source is, for example, a control board or a signal processing board for causing the image forming device to form an image. Although the outer wall of the projector is made of metal, since an opening is formed around the projection lens, radiation noise (electromagnetic wave or the like) from the noise source leaks out from the opening around the projection lens. The conductive cloth 17 suppresses the leakage of radiation noise from the opening to the outside.
An annular recess 14 c is formed between the holding portion 14 a and the side wall 14 b of the lens mount 14. Of the openings at both ends of the conductive cloth 17, one opening end 17 a is fixed to the recess 14 c via the fixing member 18.

FIG. 4 is a perspective view schematically showing a conductive cloth fixing assembly including the conductive cloth 17 and the fixing member 18. FIG. 5 is an exploded perspective view of the conductive cloth fixing assembly.
As shown in FIGS. 4 and 5, the fixing member 18 includes a fixing metal fitting that is a support member and an annular pressing member. The fixing bracket includes an annular support surface 18a and a plurality of support plates 18b formed along the circumferential direction on the outer peripheral portion of the support surface 18a. The support plates 18b are arranged so as to form annular polygonal side walls, and holes 18c are formed in each support plate 18b.

The holding member has holding metal fittings 18d and 18e. Claws 18f corresponding to the holes 18c of the support plate 18b are formed in the presser fittings 18d and 18e. The presser fittings 18d and 18e are connected to each other at one end and fixed to each other with screws 18g to form one annular polygonal metal fitting. The shape of the annular polygonal bracket made up of the presser fittings 18d and 18e substantially coincides with the shape of the annular polygonal side wall made up of the plurality of support plates 18b.
The opening end 17a of the conductive cloth 17 is sandwiched between the annular polygonal fitting and the annular polygonal side wall. The conductive cloth 17 is fixed by sandwiching the conductive cloth 17 between the claws 18f of the presser fittings 18d and 18e and the corresponding holes 18c of the support plate 18b.

A plurality of fixing through holes 18h are formed in the support surface 18a, and a screw 18i is screwed into a screw hole provided in the concave portion 14c of the lens mount 14 through the through holes 18h, thereby fixing members. 18 is fixed.
The other open end 17 b of the conductive cloth 17 is fixed to an opening of a housing (not shown) that accommodates the box 20. The opening of the housing is formed on the side surface facing the opening 20 b of the box 20. The means for fixing the open end 17b to the opening of the housing is not particularly limited. A means for fixing using a belt, a fixing bracket or the like can be used. For example, a plurality of cuts are formed at predetermined intervals in the opening end 17b, and a plurality of fan-shaped fixing surfaces are formed by these cuts. These fixing surfaces are fixed to the side surface where the opening is formed by a fixing metal fitting.

According to the optical unit of the present embodiment, in addition to the effects described in the first embodiment, leakage of radiation noise to the outside can be prevented by the conductive cloth 17.
In addition, in the embodiment in which the rubber boot 15 and the conductive cloth 17 are fixed to the same lens mount 14, the opening end 15b of the rubber boot 15 is fixed to the outer peripheral surface of the side wall 14b, and the opening end 17a of the conductive cloth 17 is a recess adjacent to the side wall 14b. It fixes to 14c. With this configuration, the size can be reduced.

(Other embodiments)
The optical unit of the other embodiment has the same structure as that of the second embodiment described above, but includes a shift prevention structure. The box 20 includes an upper case 20-1 and a lower case 20-2. Both the upper case 20-1 and the lower case 20-2 are formed using a mold. However, since the precision of the mold formation is not so high, the XYZ axial displacements orthogonal to each other at the joint portion between the upper case 20-1 and the lower case 20-2, particularly the upper and lower joint portions of the opening 20b. As a result, the dustproof effect may be reduced. The optical unit of this other embodiment includes first to third misalignment prevention structures for suppressing displacement in the XYZ axial directions.

FIG. 6 is a schematic diagram showing a first shift prevention structure. As illustrated in FIG. 6, the first shift prevention structure includes screw fixing portions 31 a and 31 b. The opening 20b has a first frame portion 30a on the upper case 20-1 side and a second frame portion 30b on the lower case 20-2 side. Each of the first frame portion 30a and the second frame portion 30b has a U-shape, and one end portions are joined to each other, and the other end portions are joined to each other.
The screw fixing portion 31a is provided in the vicinity of the joint portion 32a between the one end portions of the first frame portion 30a and the second frame portion 30b. The screw fixing portion 31b is provided in the vicinity of the joint portion 32b between the other ends of the first frame portion 30a and the second frame portion 30b. Since the screw fixing portion 31a and the screw fixing portion 31b fix the upper case 20-1 and the lower case 20-2 in the vicinity of the joint portions 32a and 32b, a shift in the Z-axis direction (vertical direction) can be suppressed. .

FIG. 7 is a schematic diagram showing a second shift prevention structure. The partial view (a) is a schematic view of the opening of the box, and the partial view (b) is an enlarged view of the joint of the opening.
As shown in FIG. 7, the second shift preventing structure has nested structures 33a and 33b. The nested structure 33a is formed in the joint portion 32a, and the nested structure 33b is formed in the joint portion 32b.
In the joint portion 32a, the nesting structure 33a includes an L-shaped receiving portion 34a formed at an end portion on the upper case 20-1 side and an I-shaped protrusion formed at an end portion on the lower case 20-2 side. Part 34b. Nesting structure 33a is formed by joining projection part 34b so that it may fit in receiving part 34a. The receiving part 34a suppresses the protrusion 34b from moving in the direction toward the outside.

In the joint part 32b, the nesting structure 33b also has the same structure (the receiving part 34a and the protruding part 34b) as the nesting structure 33a. The nesting structure 33b is formed by joining the protruding portion 34b so as to fit into the receiving portion 34a. The receiving part 34a suppresses the protrusion 34b from moving in the direction toward the outside.
The displacement in the X-axis direction can be suppressed by the nested structures 33a and 33b.

  FIG. 8 is a schematic diagram showing a third shift prevention structure. As shown in FIGS. 6 to 8, the third shift prevention structure has fitting portions 34 and 35. The fitting part 34 is provided adjacent to the joint part 32a, and has an L-shaped receiving part 34a and a corner part 34b. By joining the corner portion 34b so as to be fitted into the receiving portion 34, a shift in the Y-axis direction can be suppressed. The fitting portion 35 has the same configuration as the fitting portion 34, and can suppress a shift in the Y-axis direction.

(projector)
A projector according to the present invention includes the optical unit with a dustproof function described in any of the above-described embodiments, and a projection lens that projects an image formed by the image forming device. The projection lens is bonded to the lens mount of the optical unit.

FIG. 9 is a block diagram showing an embodiment of the projector of the present invention.
The projection display apparatus 1100 includes a light source 1101, an optical engine unit 1102, an image forming unit 1103, and a projection lens (projection optical system) 1104. The image forming unit 1103 includes display devices 1105 to 1107 that modulate light according to an image signal, and has a function of forming an image based on light emitted from the optical engine unit 1102. In the present embodiment, a digital micromirror device (DMD) that is a reflective display element is used as the display devices 1105 to 1107. Furthermore, in this embodiment, the image forming unit 1103 includes three display devices 1105 to 1107 corresponding to red light, green light, and blue light. The projection lens 1104 has a function of projecting light emitted from the image forming unit 1103 onto a screen 1109 and displaying the image as an image.

The structure of the above-described optical unit with a dustproof function may be applied to the image forming unit 1103. The structure of the above-described optical unit with a dustproof function may be applied to a part including the image forming unit 1103 and the optical engine unit 1102 or a part including the image forming unit 1103, the optical engine unit 1102 and the light source 1101.
Further, the projection display apparatus 1100 may include a cooling device for cooling the DMD of the image forming unit.

DESCRIPTION OF SYMBOLS 1 Optical unit 2 Image forming device 3 Projection lens 4 Lens mount 5 Elastic member 5a, 5b Open end 5c Convex part 10 Box 10b Open part 10c Groove part

Claims (11)

An image forming device for forming an image;
A lens mount to which a projection lens for projecting the image is joined;
A box containing the image forming device and the lens mount;
A cylindrical elastic member having both ends opened,
The box includes a first opening on a side surface facing the lens mount,
Of the openings at both ends of the elastic member, one opening end is joined to the first opening, and the other opening end is joined to the lens mount,
A joint portion between the one opening end and the first opening portion has a labyrinth seal structure, and the labyrinth seal structure includes a first groove portion formed so as to surround the first opening portion, and the first groove portion. An optical unit with a dustproof function, having a first convex part fitted in one groove part. In the optical unit with a dustproof function according to claim 1,
The elastic member includes an annular first contact surface that is in contact with the side surface of the box at the one opening end,
An optical unit with a dustproof function, wherein the first groove is formed on the side surface, and the first convex portion is formed on the first contact surface. In the optical unit with a dustproof function according to claim 2,
The lens mount is
A circular support for supporting the cemented surface of the projection lens;
A side wall formed so as to surround the outer periphery of the support part,
An optical unit with a dustproof function, further comprising a first fixing member that fixes the other opening end of the elastic member to the side wall. In the optical unit with a dustproof function according to claim 3,
The first fixing member has a dustproof function having an annular fixing belt that sandwiches the other opening end with the side wall in a state where the side wall is fitted into the other opening end of the elastic member. Optical unit. In the optical unit with a dustproof function according to claim 3,
The first fixing member includes a labyrinth seal structure, and the labyrinth seal structure includes a second groove portion formed so as to surround the side wall, and a second convex portion fitted in the second groove portion. An optical unit with a dustproof function. In the optical unit with a dustproof function according to claim 5,
The elastic member includes an annular second contact surface that is in contact with the side wall at the other opening end,
An optical unit with a dustproof function, wherein the second groove is formed on the side wall, and the second protrusion is formed on the second contact surface. In the optical unit with a dustproof function according to any one of claims 3 to 6,
A housing for housing the box;
A cylindrical conductive cloth having conductivity open at both ends; and
The housing includes a second opening on a side surface of the box facing the first opening,
An optical unit with a dustproof function, wherein one of the openings at both ends of the conductive cloth is joined to the second opening, and the other opening is joined to the lens mount. In the optical unit with a dustproof function according to claim 7,
The lens mount further includes a recess formed along an outer periphery of the support portion between the support portion and the side wall,
An optical unit with a dustproof function, further comprising a second fixing member that fixes the other opening end of the conductive cloth to the recess. The optical unit with a dustproof function according to claim 8,
The second fixing member is
An annular support surface, and a plurality of support plates formed along the circumferential direction on the outer periphery of the support surface, the plurality of support plates are arranged in a polygonal shape, and a hole is formed in each support plate. A supported member,
An annular pressing metal fitting having a plurality of claws corresponding to the holes of each of the support plates,
The support surface is fixed to the recess,
An optical system with a dustproof function, wherein the plurality of claws are inserted into holes of the support plates in a state where the other opening end of the conductive cloth is sandwiched between the plurality of support plates and an annular pressing metal fitting. unit. In the optical unit with a dustproof function according to any one of claims 1 to 9,
The lens mount is an optical unit with a dustproof function configured to be movable in an optical axis direction of the projection lens and in a direction crossing the optical axis direction. An optical unit with a dustproof function according to any one of claims 1 to 10,
A projection lens for projecting an image formed by the image forming device,
The projector, wherein the projection lens is joined to the lens mount of the optical unit.

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