JP2015146007A - Optical unit, projector, and supporting method of rod integrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical unit that can fix a rod integrator while suppressing a reduction in the intensity of light.SOLUTION: An optical unit of the present invention includes a rod integrator, a supporting member that supports the rod integrator in line contact, and a pressing member that presses the rod integrator in point contact toward a position where the supporting member supports the rod integrator.

Description

  The present invention relates to an optical unit, a projector, and a method for supporting a rod integrator.

  In a projection display device or the like that projects an image, the illuminance distribution of light from the light source is not uniform, so the illuminance distribution in the projection area is not uniform, and the image quality of the projected image may deteriorate. Therefore, generally, in a projection display device or the like, a light guide element such as a rod integrator is used, and an image is projected using light with a uniform illuminance distribution of light from a light source. In such a rod integrator, incident light is totally reflected on its side surface a plurality of times, whereby the illuminance distribution is made uniform and is emitted from the emission surface.

  As one of the methods for fixing the rod integrator as described above, there is a method of fixing an end portion serving as an entrance / exit surface of the rod integrator with a fixing member. However, since the fixing member does not transmit light, the portion corresponding to the fixing member on the entrance / exit surface of the rod integrator becomes dark, and the illuminance distribution in the projection area may not be uniform. By using a glass plate having a high transmittance as the fixing member, it is possible to suppress a decrease in illuminance at the fixing point, but when the rod integrator and the fixing member are not in close contact, unevenness due to interference in the projected image Illuminance is uneven and the image is not projected properly.

  Therefore, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2010-176055), a taper rod integrator having a pair of parallel side surfaces (parallel surfaces) is fixed by bonding and pressing on the parallel surfaces. Techniques to do this are disclosed. In Patent Document 1, bonding is performed on a parallel surface where the number of reflections of light is smaller than that of a tapered surface, thereby reducing the amount of light transmitted at the bonding point on the side of the rod integrator and reducing the amount of light in the rod integrator. It is described that it can be suppressed.

JP 2010-176055 A

  The characteristics of each surface of the rod integrator have a great influence on the performance.

  When the side surface of the rod integrator is held and fixed, the light transmitted through the inside of the rod integrator is not totally reflected at the portion of the holding surface used for fixing, which causes a decrease in the light amount. This occurs even when the number of reflections is reduced as in the invention described in Patent Document 1. Further, when the rod integrator is fixed using an adhesive, there is a further concern about the generation of gas, which may further reduce the light intensity.

  In the case where the side surface of the rod integrator is pressed and fixed, for example, when the tapered surface is pressed, a force also acts in the axial direction, which may cause a shift.

  An object of the present invention is to provide an optical unit, a projector, and a rod integrator support method capable of fixing a rod integrator while suppressing a decrease in light amount.

In order to achieve the above object, the optical unit of the present invention comprises:
A rod integrator,
A support member for supporting the rod integrator by line contact;
A pressing member that presses the rod integrator in a point contact toward a portion where the support member supports the rod integrator.

In order to achieve the above object, the projector of the present invention provides:
The above optical unit;
A light source that emits light toward the optical unit;
A light modulation element that modulates light emitted from the optical unit according to a video signal;
A projection unit that projects the modulated light.

In order to achieve the above object, the rod integrator support method of the present invention comprises:
A step of supporting the rod integrator in line contact with the support member;
Pressing the rod integrator with a point contact toward a location where the support member supports the rod integrator by a pressing member.

  According to the present invention, it is possible to fix the rod integrator while suppressing a decrease in the amount of light.

1 is a perspective view illustrating a schematic configuration of an optical unit 100 according to an embodiment of the present invention. It is a perspective view which shows the structure of the rod integrator 120 in FIG. It is a perspective view which shows the structure of the base 110 in FIG. It is sectional drawing along the A-A 'line | wire in FIG. It is a perspective view which shows the structure of the press member 131 in FIG. It is a perspective view which shows the nail | claw part 504 and the rod integrator 120 in the optical unit 100 in FIG.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated with reference to drawings.

  FIG. 1 is a perspective view showing a schematic configuration of an embodiment of an optical unit according to the present invention.

  The optical unit 100 includes a pedestal 110, a rod integrator 120, and pressing members 131 and 132.

  The pedestal 110 includes support members 111 and 112 having openings. Further, the support member 111 has one surface 111 </ b> A that faces in the opposite direction to the support member 112.

  The rod integrator 120 is a columnar optical member having a square cross section, such as a glass rod such as BK7, and is disposed so as to pass through the openings of the support members 111 and 112. The rod integrator 120 has a tapered shape in which light is guided from the side supported by the support member 111 toward the side supported by the support member 112 and the cross section becomes smaller in the direction of guiding the light. To do.

  The pressing members 131 and 132 are elastic bodies such as leaf springs, and include a surface parallel to each side surface of the rod integrator 120 and an inclined surface inclined with respect to each side surface. The pressing members 131 and 132 are provided so as to straddle the rod integrator 120. ing. The pressing members 131 and 132 have claw portions (not shown in FIG. 1) on the inclined surfaces, and the claw portions press the rod integrator 120.

  In the following description, the direction in which the rod integrator 120 guides light will be described as the x-axis direction, the x-axis direction and the direction intersecting the stacking direction of each component as the y-axis direction, and the stacking direction of each component as the z-axis direction. .

  The support members 111 and 112 and the pressing members 131 and 132 are different in size, but have the same configuration and function. Therefore, only the support member 111 and the pressing member 131 will be described below, and the description of the support member 112 and the pressing member 132 will be omitted.

  Next, a detailed configuration of the rod integrator 120 will be described with reference to FIG.

  FIG. 2 is a perspective view showing the configuration of the rod integrator 120 shown in FIG.

  The rod integrator 120 has an incident surface 201, an exit surface 202, and four side surfaces 203 to 206. Further, a ridge line 207 is provided at a location where the side surface 203 and the side surface 204 intersect.

  Next, the support member 111 will be described in detail with reference to FIGS.

  FIG. 3 is a diagram showing the configuration of the pedestal 110 in FIG.

  A ridgeline 301 is provided at a location where one surface 111A of the support member 111 and the inner surface of the opening of the support member 111 on the negative direction side of the z axis intersect. In addition, a ridgeline 302 is provided at a location where one surface 111A of the support member 111 and the inner surface on the negative direction side of the y-axis of the opening of the support member 111 intersect.

  FIG. 4 is a view showing a cross section along the x-axis direction of the A-A ′ line in the vicinity of the support member 111 shown in FIG. 1.

  The support member 111 supports the rod integrator 120 by making line contact with the side surface 205 of the rod integrator 120 at the ridgeline 301. Although not shown in FIG. 4, the support member 111 is in line contact with the side surface 206 of the rod integrator 120 at the ridgeline 302. Thus, the support member 111 makes line contact with each of the two side surfaces 205 and 206. The two side surfaces 205 and 206 are side surfaces adjacent to each other among the side surfaces 203 to 206 of the rod integrator 120.

  Next, the pressing member 131 will be described in detail with reference to FIGS.

  FIG. 5 is a perspective view showing the configuration of the pressing member 131 in FIG.

  The pressing member 131 has protrusions 501 to 503 that protrude in the x-axis direction on each of the surfaces extending in the z-axis direction and on the inclined surface. The protruding portions 501 to 503 have the same length protruding in the x-axis direction, and their tips are on the same plane. Further, a claw portion 504 is provided at the tip of the protruding portion 503, and the claw portion 504 has a ridge line 505.

  Here, referring to FIG. 1, the pressing member 131 is attached to the base 110 such that the protruding portions 501 and 502 are in contact with the one surface 111 </ b> A of the supporting member 111. By being attached in this way, the ridge lines 301 and 302 of the support member 111 and the ridge line 505 of the claw portion 504 of the pressing member 131 exist on the same plane.

  FIG. 6 is a perspective view showing the claw portion 504 and the rod integrator 120 in the optical unit shown in FIG.

  The ridge line 505 of the claw portion 504 makes point contact so as to intersect the ridge line 207 of the rod integrator 120. Accordingly, the force with which the pressing member 131 presses the rod integrator 120 concentrates on the point contact portion, so that the claw portion 504 bites into the rod integrator 120. As described above, the pressing member 131 presses the rod integrator 120 by point contact toward the place where the support member 111 supports the rod integrator 120.

  When the pressing force of the pressing member 131 is large, the bite becomes large and the rod integrator 120 may be destroyed. Therefore, the pressing member 131 needs to be designed so that the claw portion 504 bites into the rod integrator 120 is the minimum necessary.

  As described above, the optical unit 100 according to this embodiment includes the rod integrator 120, the support member 111 that supports the rod integrator 120 by line contact, and the pressing member 131 that presses the rod integrator 120 by point contact. .

  The rod integrator 120 is fixed by making line contact and point contact with the support member 111 and the pressing member 131. Further, since no adhesive member is used, there is no adhesive portion on the side surface of the rod integrator 120. Accordingly, since the refractive index does not substantially change on the side surface of the rod integrator 120, it is possible to suppress a decrease in the amount of light due to the fact that the light transmitted through the rod integrator 120 is not totally reflected.

  In addition, since no adhesive member is used, there is no risk of gas generation, and a reduction in the amount of light can be suppressed.

  Further, the claw portion 504 of the pressing member 131 makes point contact with the ridge line 207, and the pressing force of the pressing member 131 concentrates on the point contact portion, so that the claw portion 504 bites into the rod integrator 120. Therefore, since the claw portion 504 suppresses the movement of the rod integrator 120, a shift in the axial direction (x-axis direction) hardly occurs.

  Further, in the rod integrator 120, the place where the support member 111 makes line contact and the place where the claw portion 404 makes point contact exist on the same plane. Therefore, the action direction of the pressing force from the pressing member 131 to the rod integrator 120 and the action direction of the reaction force from the support member 111 to the rod integrator 120 generated when the rod integrator 120 is pressed against the support member 111 are: It exists in the same plane crossing the axial direction of the integrator 120. On the other hand, when the tapered surface is pressed by surface contact, the direction of action of the pressing force from the pressing member and the reaction force from the support member may not exist on the same plane. Therefore, since no force acts on the rod integrator 120 in the axial direction, the axial displacement is less likely to occur than when the tapered surface is pressed by surface contact.

  In the present embodiment, the rod integrator 120 has been described using an example in which the rod integrator 120 is in line contact with the support member 111 and is in point contact with the pressing member 131, but is not limited thereto. The rod integrator 120 is brought into contact with and held at four points with the support member 111 and the pressing member 131, whereby the axial direction thereof is determined. Therefore, as a modification, the support member 111 may be provided so as to contact the rod integrator 120 at three points.

  In the present embodiment, the rod integrator 120 is described using an example in which the shape is tapered, but the present invention is not limited to this. The rod integrator 120 may have a constant cross-sectional size. In such a case, the support member 111 can support the rod integrator 120 by line contact by forming the opening of the support member 111 so that the inner surface thereof is not parallel to the side surface of the rod integrator 120. Therefore, the same effect as this embodiment can be obtained.

  In the present embodiment, the example in which the rod integrator 120 has a quadrangular cross section has been described, but the present invention is not limited thereto. The cross section of the rod integrator 120 may be a polygon other than a quadrangle.

DESCRIPTION OF SYMBOLS 100 Optical unit 110 Base 111,112 Support member 120 Rod integrator 131,132 Press member 201 Incident surface 202 Output surface 203,204,205,206 Side surface 207,301,302,505 Edge line 501,502,503 Projection part 504 Claw part

Claims (9)

A rod integrator,
A support member for supporting the rod integrator by line contact;
An optical unit, comprising: a pressing member that presses the rod integrator by point contact toward a place where the support member supports the rod integrator. The optical unit according to claim 1,
The optical unit according to claim 1, wherein the support member is in line contact with each of two side surfaces of the rod integrator. The optical unit according to claim 1 or 2,
In the rod integrator, the portion supported by the support member and the portion pressed by the pressing member are present in the same plane. The optical unit according to any one of claims 1 to 3,
The pressing member has a claw portion,
The optical unit according to claim 1, wherein the claw portion is in contact with the ridgeline of the rod integrator. The optical unit according to claim 4,
The pressing member has a plurality of protrusions whose respective tips are in the same plane,
The optical unit according to claim 1, wherein the claw portion is provided at one end of the protruding portion. The optical unit according to any one of claims 1 to 5,
2. The optical unit according to claim 1, wherein the rod integrator has a tapered shape. The optical unit according to any one of claims 1 to 6,
Each of the support member and the pressing member includes a plurality of optical units. The optical unit according to any one of claims 1 to 7,
A light source that emits light toward the optical unit;
A light modulation element that modulates light emitted from the optical unit according to a video signal;
And a projection unit that projects the modulated light. A step of supporting the rod integrator in line contact with the support member;
A method of supporting a rod integrator, comprising: pressing the rod integrator by point contact toward a position where the supporting member supports the rod integrator by a pressing member.

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