JP6435570B2 - Lens holding member, lens unit, and image projection apparatus - Google Patents

Description

  The present invention relates to a lens holding member for supporting an optical member such as a lens, a lens unit having the lens holding member, and an image projection apparatus.

In an optical device using a lens represented by a camera or a projector, as a configuration for supporting the lens, for example, a configuration in which a lens edge portion is provided and an unused portion of the lens is fixed using a screw or a pressing member is known. (For example, refer to Patent Documents 1 and 2).
In addition, a configuration in which an outer peripheral portion of a lens holding member such as heat caulking is melted and the lens is restrained (see, for example, cited document 3) is also known.

By the way, in recent optical devices, particularly image projection devices, in order to achieve the two contradictory purposes of increasing the diameter of the lens and saving space, an unnecessary portion in terms of optical characteristics is required particularly in a large-aperture lens. Cut non-circular lenses are often used.
However, when such a non-circular lens is used, it is difficult to press the lens uniformly with a lens holding structure such as heat caulking, and there is a concern that the fixing accuracy deteriorates.
In addition, simply fixing a large-diameter lens using a fixing member such as a screw increases the fixing member in accordance with the size of the lens, which may increase the space and the number of components.
In order to solve such a problem, a configuration in which the lens is inserted in a direction orthogonal to the optical axis of the lens and held by a locking portion formed on the lens is conceivable (see, for example, Patent Document 4).

  However, if the lens is simply provided with a locking portion, the weight increases due to an increase in the diameter of the lens, and the lens may drop off or be displaced due to vibration or impact in a direction perpendicular to the lens optical axis. There are concerns.

  The present invention has been made in view of the above problems, and is stable against vibration and impact in a direction perpendicular to the lens optical axis while suppressing an increase in space and the number of parts. An object is to provide a lens holding member capable of holding a lens.

In order to solve the above-described problems, a lens holding member according to the present invention moves a non-circular lens that is asymmetric with respect to a lens optical axis in a radial direction perpendicular to the lens optical axis, thereby A fitting portion that can be inserted into the fitting portion, and when the non-circular lens is inserted into the fitting portion, the fitting is performed with the outer peripheral end portion that is formed so as to surround the downstream side in the insertion direction of the non-circular lens. A first holding portion that regulates the radial position and the lens optical axis position of the outer peripheral end portion by being in an inserted state in which the portion is engaged; and in the inserted state, the lens optical axis direction A lens receiving portion for forming a fixed state that opposes the upstream end of the non-circular lens in the insertion direction and restricts the movement of the non-circular lens in the lens optical axis direction; The lens receiving portion is the A second holding portion that includes a protrusion that restricts movement of the circular lens in the optical axis direction of the lens and restricts movement of the non-circular lens in the radial direction when engaged with the first holding portion. And a groove formed in the first holding portion that engages with the protrusion and defines the moving direction of the second holding portion in the lens optical axis direction, and the second holding portion is The fixed portion that fits with the first holding portion in the fixed state and restricts movement in the lens optical axis direction, and abuts on the end of the non-circular lens on the upstream side in the insertion direction, and the non-circular lens An L-shaped end portion that restricts movement in the lens optical axis direction, and the groove portion engages with the projection portion in the inserted state to guide the projection portion in the lens optical axis direction. The first holding part and the second holding part are fitted and fixed in To form a state.

  According to the present invention, it is possible to stably hold a lens against vibration and impact in a direction perpendicular to the lens optical axis while suppressing an increase in space and the number of parts.

It is a perspective view which shows an example of a structure of the image projector in embodiment of this invention. It is a figure which shows an example of a structure of the lens holding member in embodiment of this invention. It is sectional drawing which shows an example of the positional relationship of the lens holding member shown in FIG. It is a perspective view which shows an example of a structure of the 2nd holding | maintenance part in this invention. It is a perspective view which shows an example of operation | movement of the lens holding member in this invention. It is sectional drawing which shows an example of a structure of the engaging part of the 1st holding | maintenance part and lens in A part shown in FIG. It is sectional drawing which shows another example of a structure of the engaging part of the 1st holding | maintenance part shown in FIG. 6, and a lens. It is sectional drawing which shows another example of a structure of the engaging part of the 2nd holding | maintenance part and lens in this invention.

FIG. 1 shows an image projection apparatus 2 including a fixed lens unit 5 and a movable lens unit 6 as lens holding members as an example of an embodiment of the present invention. Hereinafter, with the lens optical axis of the projection lens L3 provided in the image projector 2 as the Z axis, the X, Y, and Z axes and their directions are determined as shown in FIG.
The image projection apparatus 2 includes a light source (not shown) that emits a light beam, and three liquid crystal panels PN that are image display units that give image information corresponding to the three primary colors of RGB to the light beam incident from the light source.
The image projection device 2 is a so-called three-plate color projector, and projects a prism 201 serving as a color synthesizing unit provided at a portion surrounded by three liquid crystal panels PN and image information color-combined by the prism 201. Lens unit 4.

  Here, a halogen lamp is used as the light source of the image projector 2. The light source may be a metal halide lamp, a high-pressure mercury lamp, an LED, or the like.

  The liquid crystal panel PN is a transmissive image display surface. For example, RGB three source colors are obtained by two-dimensionally modulating the intensity distribution of a light beam incident from a light source in accordance with an image displayed on the image display surface. The image information for each color corresponding to each color is given to the transmitted light flux.

  The prism 201 combines the image information for each color transmitted through each liquid crystal panel PN and forms color image information in the transmitted light flux. The prism 201 has a function as a deflecting unit that deflects incident light from each of the −Z direction, the + Y direction, and the −Y direction and projects it in the −Z direction.

The lens unit 4 includes a movable lens unit 6 that can move in the Z-axis direction and a fixed lens unit 5. Both the movable lens portion 6 and the fixed lens portion 5 have a function as a lens holding member.
As shown in FIGS. 2A and 2B, the movable lens unit 6 has a plurality of lenses L1, L2, and L3 in order from the downstream side in the Z-axis direction.
The lenses L1, L2, and L3 are preferably plastic lenses in consideration of processability, but may be glass lenses or other optical materials. Here, among the lenses L1, L2, and L3, at least the projection lens L3 that is the most upstream in the Z direction is asymmetric with respect to the Z axis that is the lens optical axis, and when viewed from the Z axis direction, the X axis positive direction. This is a substantially semicircular lens having a curvature on the side.

A method of projecting an image with the above configuration will be described.
The luminous flux emitted from the light source passes through each liquid crystal panel PN and is given image information, and then synthesized by the prism 201, thereby converting the image information for each color into color image information.
The luminous flux to which such color image information is given passes through the lens unit 4 from the Z-axis downstream side toward the Z-axis upstream side, passes through the lenses L1 and L2 in order, and then most upstream in the Z-axis direction. An image is projected on a projection surface (not shown) through the projection lens L3 on the side.
With this configuration, the image projection device 2 projects a projection image obtained by enlarging the image displayed on the image display surface onto the projection surface.

  At this time, the magnification of the image projected on the projection surface is changed by adjusting the object distance and the image distance. That is, the object distance is changed by adjusting the distance between the fixed lens unit 5 and the liquid crystal panel PN, and the image distance is changed by adjusting the Z-direction distance between the movable lens unit 6 and the projection surface.

  When the magnification of the projected image is changed by the method as described above, the image plane falls down with respect to the projection plane or the shape of the projected image becomes trapezoidal, so the movable lens unit 6 is displaced in the Z-axis direction. To correct the deviation of the shape of the projected image.

In the image projection apparatus 2 having such a configuration, the lens including the projection lens L3 is fixed to the movable lens unit 6 or the fixed lens unit 5 which is a lens holding member.
Especially when using a non-circular lens as the lens, it is difficult to press uniformly with the conventional lens holding method, and there is a concern that the accuracy of fixing deteriorates, the space required for fixing increases, and the number of parts increases. ing.
Therefore, in the present invention, the lens is fixed to the lens holding member by the configuration described below.

A method for supporting the projection lens L3 will be described.
Although only the projection lens L3 will be described here, it goes without saying that the same lens support method or lens support member may be used for the lenses L1 and L2. Further, such a configuration may be used for other lenses constituting the lens unit 4.

FIG. 3 shows a cross-sectional view of the movable lens portion 6 extracted from the lens unit 4 in particular.
In FIG. 3, a projection lens L3 is an optical region P for projecting an incident light beam and a portion that is not used optically, and an outer peripheral end provided on the side having a curvature along the outer periphery of the optical region P. Q.

  The movable lens portion 6 includes a fitting portion 16 formed in a hook shape so as to be inserted when the outer peripheral end portion Q is moved in the X direction, and a first holding that regulates the position of the outer peripheral end portion Q. Part 8 and a second holding part 9 that restricts the movement of the projection lens L3 in combination with the first holding part 8.

The first holding portion 8 is inserted in the outer peripheral end portion Q, and the outer peripheral end portion Q and the fitting portion 16 are brought into contact with each other, that is, engaged with each other, that is, the X direction, the Y direction of the projection lens L3, It has a function as a temporary fixing means for restricting movement in the Z direction.
The first holding unit 8 also engages with the second holding unit 9 to define the moving direction of the second holding unit 9 in the Z direction when the second holding unit 9 is inserted by moving in the Z direction. It has the groove part 17 for doing.
The fitting portion 16 has flexibility and is set to press and hold the outer peripheral end Q by elastically deforming so as to spread in the Z-axis direction when the outer peripheral end Q is inserted.

As shown in FIGS. 4 (a) and 4 (b), the second holding portion 9 is associated with the lens receiving portion 91 that is a lens supporting portion for restricting the movement of the projection lens L 3 in the Z-axis direction, and the groove portion 17. In addition, a projection 92 that restricts movement in the XY plane including the radial direction of the projection lens L3 is provided.
The second holding portion 9 also has a fixing portion 93 that fits with the first holding portion 8 and restricts movement in the Z-axis direction when inserted into the first holding portion 8 to the end in the Z direction. .

The lens receiving portion 91 includes a flat portion 91a that is substantially parallel to the YZ plane, and an L-shaped end portion 91b that rises toward the end of the flat portion 91a in the X direction and has a L-shaped cross section. Have.
The L-shaped end portion 91b is formed along the surface on the upstream side in the X direction opposite to the downstream side in the insertion direction of the projection lens L3 into the first holding portion 8 in a fixed state to be described later. -Restricts movement in the Z direction.
When the second holding portion 9 is inserted into the first holding portion 8, the flat surface portion 91a abuts and supports the projection lens L3 on the opposite side to the downstream side in the insertion direction of the projection lens L3 into the first holding portion 8, thereby supporting the projection lens. The movement of L3 in the -X direction is restricted.
With this configuration, the lens receiving portion 91 is arranged to face the end portion on the upstream side in the X direction, which is the insertion direction orthogonal to the lens optical axis of the projection lens L3, in the fixed state, thereby moving the projection lens L3. To regulate.
The protrusions 92 are arranged at both ends of the second holding unit 9 in the Y direction, and similarly, the movements in directions other than the Z direction are restricted by the groove portions 17 arranged at both ends of the first holding unit 8 in the Y direction. It is guided by engaging with the groove portion 17.

The fixing portion 93 is a member formed in a pair on the downstream side in the Z direction of the second holding portion 9, in other words, on the side inserted first into the first holding portion 8.
The fixing portion 93 is a light that fixes the position of the second holding portion 9 in the Z direction by inserting and fixing a hook-shaped projection (not shown) formed in the first holding portion 8 in a fixed state to be described later. It functions as an axial positioning part. Here, the insertion means that the hook-shaped protrusion is inserted into the fixing portion 93 and penetrates. In addition, such a configuration may be a configuration in which the hook-shaped protrusion and the fixing portion 93 are engaged and fixed to each other by an elastic force like a so-called snap fit.
The fixing portion 93 can position the second holding portion 9 in the Z direction while suppressing an increase in the number of parts, and the projection lens L3 is fixed with high accuracy.

An operation for fixing the lens using the lens holding member having such a configuration will be described.
FIGS. 5A, 5B, and 5C show a fixing method when the projection lens L3 is inserted into the movable lens unit 6. FIG.
First, as shown in FIG. 5A, the projection lens L <b> 3 is moved in the X direction so that the outer peripheral end Q is inserted into the fitting part 16 of the first holding part 8.

  The state shown in FIG. 5B in which the projection lens L3 is inserted in the X direction up to the terminal end of the first holding unit 8 is an insertion state. In the inserted state, the projection lens L3 is supported by the first support portion 8 and is in a temporarily fixed state in which movement in the X direction, the Y direction, and the Z direction is restricted.

The first support portion 8 is provided with a groove portion 17 at a position on the upstream side in the Y direction with respect to the bottom surface that is the surface opposite to the insertion direction of the projection lens L3 in the inserted state.
In such an insertion state, when the second holding portion 9 is moved in the insertion direction parallel to the Z direction, the flat portion 91a slides while contacting the bottom surface of the projection lens L3, so that the X direction of the projection lens L3 Move while restricting movement to.
When the insertion operation is finished and the fixing portion 93 is fitted and fixed to the first holding portion 8, the first holding portion 8 and the second holding portion 9 are mutually connected as shown in FIG. A fixed state is formed.
At this time, as shown in FIG. 6, the fitting portion 16 is elastically deformed by inserting the outer peripheral end portion Q, and press-holds the outer peripheral end portion Q with an elastic force. FIG. 6 is an enlarged view of a portion B shown in FIG. 2 and shows a portion where the fitting portion 16 and the projection lens L3 are in contact with each other.
As shown in FIG. 6, the fitting portion 16 abuts and engages with the outer peripheral end portion Q, so that the U-shaped receiving recess is expanded in the Z-axis direction and is supported by the projection lens L3. Is done.

In the fixed state, in the lens receiving portion 91, the flat surface portion 91a abuts against the bottom surface of the projection lens L3 to restrict the movement of the projection lens L3 in the X direction, and the L-shaped end portion 91b is an optical region of the projection lens L3. Abutting on the outer edge of P restricts movement in the Z direction.
By forming a fixed state with the second support portion 9, the lens can be stably protected against vibration and shock in the X direction orthogonal to the lens optical axis while suppressing an increase in space and the number of parts. Retained.
In such a configuration, the lens receiving portion 91 is a lens support portion that contacts and supports the end of the projection lens L3 on the opposite side in the insertion direction.
By forming the fixed state with the lens receiving portion 91, the lens can be more stably protected against vibration and impact in the X direction orthogonal to the lens optical axis while suppressing an increase in space and the number of parts. Retained.

The second holding part 9 has a fixing part 93 that fits with the first holding part 8 in a fixed state and restricts movement in the Z direction.
With this configuration, the first holding unit 8 and the second holding unit 9 are fixed to each other in a fixed state while suppressing an increase in space and the number of parts, so that vibration in a direction perpendicular to the lens optical axis can be reduced. Holds the lens stably against impact.

The fitting portion 16 can be elastically deformed. When the outer peripheral end Q of the projection lens L3 is inserted into the fitting portion 16, the fitting portion 16 holds the outer peripheral end Q with an elastic force. Yes.
With this configuration, it is possible to hold the lens more stably against vibrations and shocks in a direction perpendicular to the lens optical axis while suppressing an increase in space and the number of parts.
Further, with this configuration, the projection lens L3 is stably held even during the insertion operation from the insertion state to the fixed state, whereby the insertion operation of the second holding unit 9 is easily performed.

Moreover, the fitting part 16 may have the fitting protrusion part 16a which is a protrusion which protrudes in the Z-axis direction and has flexibility, as shown in FIG.
With this configuration, the lens can be held more stably against vibrations and impacts in the direction perpendicular to the lens optical axis while suppressing an increase in space and the number of parts.
Further, with this configuration, the projection lens L3 is stably held even during the insertion operation from the insertion state to the fixed state, whereby the insertion operation of the second holding unit 9 is easily performed.

As shown in FIG. 8, both ends of the first holding portion 8 in the Y direction are downstream of the groove portion 17 in the X direction so as to come into contact with the end of the projection lens L3 opposite to the insertion direction in the inserted state. You may form the latching | locking part 18 which is the trapezoidal convex part provided in this. Here, FIG. 8 is an enlarged view of an A portion indicated by a broken line in FIG.
According to such a configuration, the projection lens L3 is locked when the bottom surface, which is the end portion on the downstream side in the X direction, is brought into contact with and held by the locking portion 18 in the inserted state, that is, locked. This restricts movement in the X direction.
With this configuration, the insertion operation of the second holding unit 9 is easily performed by stably holding the projection lens L3 even during the insertion operation from the insertion state to the fixed state.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.

  For example, the image projection apparatus 2 is a three-plate type color projector, but is not limited thereto, and may be a one-plate type that provides color image information with a single liquid crystal panel, or a monochrome image projection. It may be a device.

  Further, such a lens holding member may be used in a lens unit for fixing a lens used in an optical device such as an imaging device in addition to the image projection device.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

2 Image projection device 4 Lens unit 5 Lens holding member (fixed lens portion)
6 Lens holding member (movable lens part)
8 First holding part 9 Second holding part 16 Fitting part 16a Fitting projection part 17 Groove part 91 Lens receiving part 92 Projection part 93 Fixing part L2 Non-circular lens (lens)
L3 Non-circular lens (projection lens)
P Optical region of non-circular lens Q Outer peripheral end X of non-circular lens Insertion direction (radial direction)
Z Lens optical axis direction (insertion direction)

Japanese Utility Model Publication No. 04-061307 JP 2002-228910 A JP 04-166905 A Japanese Patent No. 5469437

Claims (4)

A non-circular lens that is asymmetric with respect to the optical axis of the lens is moved in a radial direction perpendicular to the optical axis of the lens, and a fitting portion into which an outer peripheral end of the non-circular lens can be inserted; When the outer peripheral end formed so as to surround the downstream side in the insertion direction of the non-circular lens is inserted into the fitting portion, the outer peripheral end portion is brought into an insertion state in which the fitting portion is engaged. A first holding portion that regulates a position in the radial direction and a position in the lens optical axis direction;
When the lens is moved in the optical axis direction of the lens in the inserted state, it is opposed to the upstream end of the non-circular lens in the insertion direction, and the fixed state restricts the movement of the non-circular lens in the lens optical axis direction. And the diameter of the non-circular lens when the lens receiver restricts the movement of the non-circular lens in the lens optical axis direction and engages with the first holding portion. A second holding portion comprising a protrusion that restricts movement in the direction,
A groove formed on the first holding portion that engages with the protrusion and defines the moving direction of the second holding portion in the lens optical axis direction;
The second holding portion is in contact with a fixing portion that fits with the first holding portion in the fixed state and restricts movement in the lens optical axis direction, and an end on the upstream side in the insertion direction of the non-circular lens. And an L-shaped end portion for restricting movement of the non-circular lens in the lens optical axis direction,
The groove portion engages with the protrusion portion in the inserted state, and guides the protrusion portion in the lens optical axis direction so that the first holding portion and the second holding portion are fitted and fixed. A lens holding member that forms a fixed state. The lens holding member according to claim 1,
The fitting portion is elastically deformable, and the fitting portion holds the outer circumferential end portion with an elastic force when the outer circumferential end portion of the non-circular lens is inserted into the fitting portion. Lens holding member. A lens unit comprising the lens holding member according to claim 1. An image projection apparatus comprising the lens holding member according to claim 1.

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