JP7129818B2 - LENS HOLDING MEMBER AND IMAGE PROJECTION DEVICE - Google Patents

Description

The present invention relates to a lens holding member and an image projection device.

In an optical device such as an image projection device using a lens unit, which is represented by a camera or a projector, there is known a mechanism for finely adjusting the lens position when assembling the lens into the lens barrel (for example, Patent Document 1 ~4, etc.).

As a mechanism for performing such fine adjustment, there is a structure in which a pressing member such as a spring or a screw presses, but there is a problem that the number of parts increases.
A method using an eccentric cylindrical member is also conceivable, but there is a problem that the direction of adjustment depends on the direction of eccentricity.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a lens holding member that enables fine adjustment after the lens is assembled while reducing the number of parts.

In order to solve the above-described problems, a lens holding member according to the present invention includes a lens barrel that holds a lens, a first rotating member that can rotate around the central axis of the lens, and a lens that rotates independently of the first rotating member. a rotatable second rotating member; and a holding portion that holds the first rotating member and the second rotating member so as to be rotatable about the central axis with respect to the lens barrel; The first rotating member and the second rotating member are arranged on opposite sides of the holding portion in the direction of the central axis, and the holding portion is fitted to the outer peripheral side of the lens barrel. It has a plurality of mating portions, and is arranged such that an angle formed between positions where the mating portions are formed coincides with an eccentric direction, and both the first rotating member and the second rotating member It has a first surface facing the inner peripheral surface of the holding portion and a second surface facing the lens barrel side, and the first surface and the second surface are eccentrically arranged. The first rotating member and the second rotating member are arranged such that the eccentric directions are shifted by 90 degrees.

According to the present invention, it is possible to finely adjust the lens after assembly while reducing the number of parts.

It is a figure showing an example of composition of an image projection device in an embodiment of the present invention. It is a figure showing an example of composition of a lens barrel in an embodiment of the present invention. 3 is a diagram showing an example of the configuration of a lens holding member shown in FIG. 2; FIG. 3 is an exploded view showing an example of the configuration of each part of the lens holding member shown in FIG. 2; FIG. 4A and 4B are schematic diagrams showing an example of a rotating operation of the holding portion shown in FIG. 3; FIG. FIG. 4 is a diagram showing an example of a configuration of a first rotary member and a second rotary member shown in FIG. 3; 4A and 4B are diagrams showing an example of the rotation operation of the first rotating member shown in FIG. 3; FIG. It is a figure which shows an example of the rotating motion of the 2nd rotating member shown in FIG. 3 is a view of the lens barrel shown in FIG. 2 as viewed from above; FIG.

FIG. 1 shows an example of the configuration of an image projection device as an embodiment of the present invention.
The image projection device 100 has a light source 101 that emits a light flux, and a spatial light modulator 102 that displays an image to be projected and gives image information to the light flux that passes through.
The image projection apparatus 100 also includes a lens unit 200 as a projection optical system for projecting an image onto the display surface 104, and a control unit 109 for controlling the spatial light modulator 102 to display the image to be projected onto the display surface 104. and have

The light source 101 uses a halogen lamp, which is a light source for emitting light, to emit white light substantially in parallel. Here, a metal halide lamp, a high-pressure mercury lamp, or an LED may be used as the light source.
The light source 101 is a white light source, but may use a plurality of monochromatic light sources such as laser light sources corresponding to basic colors such as R, G, and B.

The spatial light modulation element 102 is a liquid crystal panel serving as an image display means that transmits an incident light beam, imparts spatial modulation to the light beam, and emits the light beam, thereby providing image information. Note that the spatial light modulator 102 may be a reflective spatial light modulator such as a DMD (digital micromirror device).

A configuration of the lens unit 200 will be described.
Here, the direction parallel to the optical axis of the light incident on the lens unit 200, that is, the center of the optical axis of the lens 16 when the lens unit 200 is attached to the image projection apparatus 100, is the Z axis, and the direction perpendicular to the Z axis is 2 is defined as the Y-axis, and the axis perpendicular to the Z-axis and the Y-axis is defined as the X-axis. Regarding the directions of the X-axis, Y-axis, and Z-axis, the direction of the arrow shown in FIG. 2 is defined as the positive direction.

As shown in FIG. 2, the lens unit 200 includes a housing 20, a lens 15 and a lens 16 arranged on the Z-axis to constitute a projection optical system, and a Z-axis parallel to the central axis of the lens 15. A rotatable first rotating member 11 , a second rotating member 12 rotatable independently of the first rotating member 11 , the first rotating member 11 , and the second rotating member 12 are arranged in a Z direction with respect to the housing 20 . and a holding portion 50 that holds the device so as to be rotatable in the X/Y directions about the axis.

The first rotating member 11, the second rotating member 12, and the holding part 50 are attached to the first lens barrel 21 and the second lens barrel 22 that constitute the housing 20 as shown in FIG. It functions as a lens holding member 1 that holds the lens 15 .

FIG. 4 shows an exploded view of each member constituting the lens holding member 1. As shown in FIG.
The first lens barrel 21 includes a substantially cylindrical portion 211 that holds the lens 15 , an abutting portion 212 that rises parallel to the XY plane from the cylindrical portion 211 , and a and an elongated tip 213 .
The lens 15 is held on the inner peripheral side of the distal end portion 213 . Further, a washer 23 is attached as a slide assisting portion so as to be in contact with the abutting portion 212 outside the cylindrical portion 211 .
The washer 23 reduces friction between the first rotating member 11 and the first lens barrel 21 even when the first rotating member 11 rotates and moves eccentrically, which will be described later.

The pressing member 17 is fixed to the second lens barrel 22 by screwing, and presses the first lens barrel 21, the holding portion 50, the first rotating member 11, and the second rotating member 12 in the Z-axis direction. It is a stopper that maintains the fastened state with

As shown in FIGS. 5(a) to 5(c), the holding portion 50 has a substantially cylindrical shape having a convex portion 51 at the center in the Z-axis direction, and is located on the +Z direction side of the convex portion 51 and is located on the first rotating member. 11 is an inner peripheral surface 52, and the portion facing the outer peripheral surface of the second rotating member 12 on the −Z direction side of the projection 51 is an inner peripheral surface 53. As shown in FIG.
As shown in FIG. 5(b), on the side surface of the convex portion 51 on the +Z direction side, a direct-acting convex portion 54 is formed along the Y direction, which is the vertical direction.
Similarly, as shown in FIG. 5C, on the side surface of the protrusion 51 on the -Z direction side, a linear motion protrusion 54 is formed along the X direction, which is the left-right direction.
Linear portions 52a and 53a are formed on both the inner peripheral surface 52 and the inner peripheral surface 53 on the outer side of the linear motion convex portion 54. are held in contact with each other.

In the present embodiment, the linear motion convex portion 54 side protrudes and is received by the linear motion groove portion 55 formed on the lens barrel side. , the convex and concave configurations may be reversed.
The linear motion convex portion 54 and the linear motion groove portion 55 fit together to function as a fitting portion. Such a fitting portion functions as a shift direction restricting member that restricts the shift direction in the rotation operation of the first rotating member 11 and the second rotating member 12, which will be described later.

The first rotating member 11 has a cylindrical portion 111 and, as shown in FIGS. 6A and 6B, a flange portion 112 formed at the end of the cylindrical portion 111 in the Z direction. there is
Similarly, the second rotating member 12 has a cylindrical portion 121 and a flange portion 122 formed at the -Z direction end of the cylindrical portion 121 .
Gear portions 113 and 123, which are gear-shaped gears, are formed on the outer peripheral side of the flange portions 112 and 122, and it is possible to drive the drive source from the outer peripheral side by fitting the gears.

The cylindrical portion 111 of the first rotating member 11 has an outer peripheral surface 111a that is a first surface and an inner peripheral surface 111b that is a second surface, as shown exaggeratedly by a dashed line in FIG. The center of the cross section is eccentric in the Y direction, which is a predetermined direction.
Since such decentration is intended for fine adjustment of the position of the lens 15 as will be described later, the actual decentration may be several millimeters.
That is, the outer peripheral surface 111a of the cylindrical portion 111 is the first surface facing the inner peripheral surface 52 of the holding portion 50 in the fastened state in which the lens holding member 1 is assembled. Similarly, the inner peripheral surface 111 b of the cylindrical portion 111 is a second surface facing the outer peripheral surface of the first lens barrel 21 .

As with the first rotating member 11, the cylindrical portion 122 of the second rotating member 12 also has the center of the cross section between the outer peripheral surface 121a as the first surface and the inner peripheral surface 121b as the second surface in a predetermined direction. It is eccentric in the X direction.
With such a configuration, the second rotating member 12 moves in a direction orthogonal to the first rotating member 11 by rotation.
The outer peripheral surface 121a of the cylindrical portion 121 is a first surface facing the inner peripheral surface 53 of the holding portion 50 in the fastened state in which the lens holding member 1 is assembled. Similarly, the inner peripheral surface 121 b of the cylindrical portion 121 is a second surface that faces the outer peripheral surface of the second lens barrel 22 .

Now, the center positions of the lenses 15 and 16 are slightly different due to accumulation of mutual tolerances. As a result, the center of the optical axis of the lens 15 attached to the first barrel 21 and the center of the optical axis of the lens 16 attached to the second barrel 22 are misaligned, and the intended performance cannot be achieved. can be.
Since such deviation of the optical axis center cannot be eliminated unless the lenses 15 and 16 are moved, adjustment after assembly is difficult.
Therefore, in this embodiment, by using the first rotating member 11 and the second rotating member 12 that can be operated from the outside even after the assembly is completed, the fine adjustment after the lens assembly is performed while suppressing the number of parts. enable

In this embodiment, the holding portion 50, the first rotating portion 11, and the second rotating portion 12 are used to move the first lens barrel 21 with respect to the second lens barrel 22, thereby finely adjusting the position of the lens 15. I will explain how to do that.

At the end of the first lens barrel 21 on the -Z direction side, a linear motion groove 55 is formed along the Y direction so as to fit into the linear motion convex portion 54 on the outer peripheral portion thereof.
Similarly, at the end of the second lens barrel 22 on the +Z direction side, a linear motion groove 55 is formed along the X direction so as to fit into the linear motion convex portion 54 on the outer peripheral portion thereof.
The straight-acting protrusion 54 and the straight-acting groove 55 are engaged with each other in the fastened state shown in FIG.

In such a fastened state, when the gear portion 113 is rotated in direction A, as shown in FIG. Being different (eccentric) results in a shift of the center of the first rotating member 11 with respect to the center of the holding part 50 .
Further, since the moving direction at this time is restricted by the linear motion convex portion 54, the first lens barrel 21 moves in the Y direction with respect to the holding portion 50 when the first rotating member 11 is rotated. Become.

Similarly, when the gear portion 123 of the second rotating member 12 is rotated in direction A, as shown in FIG. Because of (eccentricity), the center of the second rotating member 12 is shifted in the X direction with respect to the center of the holding portion 50 .
The second lens barrel 22 is attached to the -Z direction side of the holding portion 50, and the second rotating member 12 is in contact with the second lens barrel 22 on the inner peripheral surface side. When rotating with respect to the holding portion 50 , the positions of the second lens barrel 22 and the holding portion 50 change relative to each other due to the movement in the eccentric direction.
Since the moving direction at this time is restricted by the linear motion convex portion 54 formed on the -Z direction side, the second lens barrel 22 moves only in the X direction when the second rotating member 12 is rotated. becomes. In this way, by shifting the eccentric directions of the first rotating member 11 and the second rotating member 12 by 90 degrees, it is possible to freely adjust the directions perpendicular to each other.

Therefore, by rotating the first rotating member 11 and the second rotating member 12 with respect to the holding portion 50, the positional relationship between the first lens barrel 21 and the second lens barrel 22 can be changed in the X direction and the Y direction. can be fine-tuned independently.

A method of projecting an image using the lens unit 200 having such a configuration will be described.
A light flux emitted from the light source 101 is imparted with image information by passing through the spatial light modulator 102 arranged on the −Z direction side of the lens unit 200, passes through the lens unit 200, and is emitted to the display surface 104. be done.
In order for the lens unit 200 to correctly display an image on the display surface 104 , it is necessary to adjust the positional relationship with the display surface 104 and the positional relationship with the spatial light modulator 102 .
For such adjustment, a method of pressing the lens holding member 1 in a desired direction using, for example, a spring or a screw is conventionally known.
However, the method using the pressing member in this way has a problem that the number of parts increases. Further, considering work efficiency, it is desirable to adjust the position of the lens while the lens holding member 1 is attached to the lens unit 200, but springs, screws, etc. require a large work space for such adjustment. , was difficult as an adjustment method for the lens unit 200, which is becoming smaller.

Therefore, in the present embodiment, the positional relationship between the lenses 15 and 16 can be adjusted by rotating the first rotating member 11 and the second rotating member 12 .

In this embodiment, a lens barrel 21 holding a lens 15, a first rotating member 11 rotatable around the central axis of the lens 15, and a second rotating member 12 rotatable independently of the first rotating member 11 are provided. , and a holding portion 50 that holds the first rotating member 11 and the second rotating member 12 so as to be rotatable about the central axis with respect to the lens barrel 21 .
In addition, in the present embodiment, the first rotating member 11 and the second rotating member 12 are arranged opposite to each other with the holding portion 50 interposed therebetween in the Z direction. Both have first surfaces 111a and 121a facing the inner peripheral surface of the holding portion 50 and second surfaces 111b and 121b facing the lens barrel side.
The first surfaces 111a, 121a and the second surfaces 111b, 121b are formed eccentrically, and the first rotary member 11 and the second rotary member 12 are arranged so that the eccentric directions are shifted by 90 degrees.
With such a configuration, it is possible to finely adjust the lens after assembly while reducing the number of parts.

In this embodiment, the first rotating member 11 and the second rotating member 12 have gear portions 113 and 123 for driving from the outer peripheral side.
With such a configuration, even with the lens unit 200 having a small work space, fine adjustment after the lens is assembled can be easily performed.

In addition, in this embodiment, the holding portion 50 has a direct-acting convex portion 54 that fits with the outer peripheral sides of the first lens barrel 21 and the second lens barrel 22 .
With such a configuration, the movement directions of the first lens barrel 21 and the second lens barrel 22 with respect to the holding portion 50 are restricted, so that the lens position can be freely adjusted in the XY directions.

In addition, in the present embodiment, a plurality of pairs of the linear motion convex portion 54 and the linear motion groove portion 55 are provided, and the angle formed by the fitting portion coincides with the eccentric direction.
According to this configuration, the direction of shift due to the rotational motion of the first rotating member 11 and the second rotating member 12 is regulated by the direction of the fitting portion, so that the direction of motion can be easily controlled.

Although preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and unless otherwise limited in the foregoing description, the present invention is set forth in the appended claims. Various modifications and changes are possible within the scope of the spirit.

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

The effects described in the embodiments of the present invention are merely enumerations of the most suitable 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.

1 lens holding member 11 first rotating member 12 second rotating member 200 lens unit

JP 2011-076040 A JP-A-2002-196206 Japanese Patent Application Laid-Open No. 2003-066302

Claims (2)

a lens barrel holding a lens;
a first rotating member rotatable around the central axis of the lens;
a second rotating member rotatable independently of the first rotating member;
a holding portion that holds the first rotating member and the second rotating member rotatably about the central axis with respect to the lens barrel in a plane perpendicular to the central axis;
The first rotating member and the second rotating member are arranged on opposite sides of each other with respect to the central axis with respect to the holding portion,
The holding part has a plurality of fitting parts that fit with the outer peripheral side of the lens barrel, and is arranged so that an angle formed between positions where the fitting parts are formed coincides with an eccentric direction,
Each of the first rotating member and the second rotating member has a first surface facing the inner peripheral surface of the holding portion and a second surface facing the lens barrel. The first surface and the second surface are formed eccentrically, and the first rotating member and the second rotating member are arranged such that the eccentric directions are shifted by 90 degrees. lens holding member. a lens unit comprising the lens holding member according to claim 1;
a light source that emits light toward the lens unit;
and projecting light transmitted through the lens unit onto a display surface.

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