JP2019008944A - Optical Integrator Unit - Google Patents

Abstract

To provide an optical integrator unit which can fix an optical integrator without using an adhesion.SOLUTION: An optical integrator unit includes: an optical integrator 4; a housing 2 having a cylindrical space 5 which houses the optical integrator; and a light source 3 which radiates light to the optical integrator. The optical integrator unit has an optical integrator fixing part 6 at the emission surface side of the optical integrator and restricts movement of the optical integrator with the optical integrator fixing part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical integrator unit.

  Various techniques for making a luminance distribution of light emitted from a light source uniform (hereinafter also referred to as light homogenization) have been disclosed for an optical integrator (hereinafter referred to as an optical integrator) incorporated in a projection display device.

  Optical integrators used for projection display devices include rod type and fly eye type. In the rod-type optical integrator, light incident from one end face of the rod constituting the optical integrator is reflected in-plane within the rod and overlapped on the exit surface to make the luminance distribution uniform. The rod type has an advantage that it can easily cope with the miniaturization of the projection display device compared with the fly-eye type, and is suitable for a projection display device using a light emitting element as a light source.

  The rod includes a solid rod such as a glass rod and a hollow rod formed by bonding a mirror. In the hollow rod, light is reflected by using a reflecting surface of a mirror on which silver or aluminum is deposited, so that a reflection loss occurs during repeated in-plane reflection. On the other hand, a solid rod has an advantage that reflection loss is less than that of a hollow rod because in-plane reflection is almost total reflection.

For solid rods, as a technology for reducing the size of projection display devices, the solid rods are randomly filled with scattering particles that have the function of scattering light, and light is made uniform using scattering. The technique which performs is disclosed (patent document 1).
According to the technique of Patent Document 1, it is possible to realize an optical integrator that exhibits the same function with a more compact size compared to the case of using a conventional solid rod that makes light uniform by repeating total reflection. .

Japanese Patent Laid-Open No. 2006-65909

Conventionally, a rod-type optical integrator is fixed with an adhesive in a housing called an optical integrator holder or the like. In this conventional technique, there is a problem that light leaks from a bonding portion using an adhesive, leading to a decrease in light emission efficiency. Further, in the process of fixing the optical integrator in the casing, a process of UV curing the adhesive is required, and there is a problem that it takes time to fix the optical integrator.
In this specification, the ratio of the amount of light emitted from the exit surface of the optical integrator to the amount of light incident on the entrance surface of the optical integrator is defined as the light exit efficiency.

  The present invention is to solve the above problems and provide an optical integrator unit that can fix an optical integrator without using an adhesive.

As a result of intensive studies, the present inventors have found that the above problem can be solved by using a specific configuration in the optical integrator unit, and have completed the present invention. The present invention provides the following [1] to [7].
[1] An optical integrator unit comprising an optical integrator, a casing having a cylindrical space for housing the optical integrator, and a light source for irradiating the optical integrator with light.
Having an optical integrator fixing part on the light exit surface side of the optical integrator,
An optical integrator unit in which movement of the optical integrator is restricted by the optical integrator fixing portion.
[2] The optical integrator unit according to [1], wherein the optical integrator is sandwiched between the optical integrator fixing portion and the light source.
[3] The light according to [1] or [2], wherein the light integrator fixing portion includes a plate-like member made of a transparent body and a recess formed on a wall surface of the casing facing the cylindrical space. Integrator unit.
[4] The optical integrator unit according to [3], wherein both ends of the concave portion and the plate-like member are fitted.
[5] The optical integrator unit according to [3] or [4], wherein the plate-shaped member is either a lens or a polarizing plate.
[6] The optical integrator fixing portion is formed of a reflective housing having a reflective surface that reflects light emitted from the optical integrator, and the reflective surface and the output surface of the optical integrator are arranged non-parallel. The optical integrator unit according to [1] or [2].
[7] The optical integrator unit according to [6], wherein the reflective housing and the housing having the cylindrical space are formed of the same housing.

  A structure in which a cylindrical space is formed in the housing to accommodate the optical integrator, and an optical integrator fixing portion is provided on the exit surface side of the received optical integrator, and the optical integrator fixing portion regulates the movement of the optical integrator. By doing so, the optical integrator can be fixed without using an adhesive.

It is a vertical sectional view of the optical integrator unit in the first embodiment. It is a vertical sectional view of the optical integrator unit in the second embodiment.

  Hereinafter, the optical integrator unit in the first embodiment and the second embodiment of the present invention will be described in detail. In addition, this invention is not made into the following embodiment.

(First embodiment)
As shown in FIG. 1, the optical integrator unit 1 of the present embodiment includes a light source 3 and an optical integrator 4 housed inside a housing 2. As another embodiment, the light source 3 can be provided outside the housing 2.
The optical integrator 4 only needs to have an incident surface 10, an output surface 11, and a side surface 12. Other shapes are not particularly limited. For example, the cross section may be a rectangular or polygonal prism, a truncated pyramid, a cylinder, or the like.
In this specification, the incident surface 10 means a surface on which light from the light source 3 is incident, the exit surface 11 means a surface that emits incident light, and the side surface 12 means the incident surface 10 and the exit surface 11. It means the surface that connects.
As the light source 3, an LED or the like can be used.

  The optical integrator 4 is accommodated in a cylindrical space 5 formed inside the housing 2. The cylindrical space 5 is preferably a shape similar to the shape of the integrator, and is preferably a cylindrical space when the integrator is a columnar shape, and a rectangular cylindrical space when the integrator is a prismatic shape.

An optical integrator fixing portion 6 is disposed on the light exit surface side of the optical integrator 4, and the optical integrator fixing portion 6 comes into contact with the light exit surface 11 of the optical integrator 4 to restrict movement of the light integrator 4 in the direction of the light exit surface. .
In the present embodiment, the light source 3 is further disposed on the incident surface side of the optical integrator 4, and the light source 3 comes into contact with the incident surface 10 of the optical integrator 4 to restrict the movement of the optical integrator 4 in the incident surface direction. . That is, the movement of the optical integrator 4 is restricted by sandwiching and fixing the optical integrator 4 between the optical integrator fixing portion 6 and the light source 3.

In the present embodiment, the optical integrator fixing portion 6 includes a plate-like member 7 made of a transparent body and a recess 9 formed on a wall surface facing the cylindrical space 5 of the housing 2. Although the recessed part 9 will not be specifically limited if it is a structure which can hold | maintain both ends of the plate-shaped member 7, For example, the shape of the recessed part 9 and the shape of the both ends of the plate-shaped member 7 are made into substantially the same shape, It is preferable to fit the recess 9.
The recess 9 is preferably formed at a position where the distance between the lower surface of the plate-like member 7 fitted in the recess 9 and the upper surface of the light source 3 is substantially the same as the length in the longitudinal direction of the optical integrator 4.

By adopting a structure in which the optical integrator 4 is sandwiched and fixed between the upper surface of the light source 3 and the lower surface of the plate-like member 7, the optical integrator 4 can be fixed at a predetermined position without using an adhesive as in the prior art. For this reason, the problem of the fall of the light emission efficiency accompanying use of an adhesive agent and complication of an optical integrator unit manufacturing process can be avoided.
By correctly designing and correctly manufacturing the shape and position of the plate-like member 7 and the recess 9, the plate-like member 7 and the recess 9 can be easily positioned. In addition, the shape and position of the plate-like member 7 and the recess 9 are designed and manufactured correctly, and the plate-like member 7 and the recess 9 are fitted and fixed, thereby avoiding misalignment after fitting and improving accuracy. High positioning can be performed.
Further, by adopting a structure in which the light source 3 is pressed down by the optical integrator 4, the incident surface of the optical integrator 4 and the upper surface of the light source 3 are in close contact with each other, so that the light emitted from the light source 3 can be efficiently taken into the optical integrator 4. it can.

In order to hold both ends of the plate-like member 7 in the concave portion 9 that is the fitting portion 8, the plate-like member 7 having a shape in which both ends of the plate-like member 7 become protrusions fitted to the concave portion 9 is used. The plate-like member 7 of the present embodiment has a shape in which both ends of the plate-like member 7 protrude from the emission surface of the optical integrator 4 and become projecting portions in a state where the plate-like member 7 is placed on the emission surface of the optical integrator 4. Have
The plate-like member 7 is made of a transparent body that transmits light, and is preferably either a lens or a polarizing plate.
By incorporating the optical integrator unit of the present embodiment in which the plate-like member 7 is composed of a polarizing plate into a projection display device including a liquid crystal panel and a polarizing plate, external attachment of the polarizing plate becomes unnecessary. In addition, with a reflective polarizing plate, the polarized light component reflected without being transmitted can be collected inside the integrator and recycled to improve efficiency.

(Second embodiment)
As shown in FIG. 2, a reflective housing 13 having a reflective surface 14 that reflects light emitted from the optical integrator 4 can also be used.
By using the reflecting surface 14 of the reflecting housing 13 as the optical integrator fixing portion 6, the positioning of the reflecting housing 13 and the optical integrator 4 can be performed together when the optical integrator 4 is fixed.
The reflection surface 14 is a surface that is arranged non-parallel to the emission surface 11 of the optical integrator 4 and reflects the light emitted from the optical integrator 4. The angle formed by the reflecting surface 14 and the exit surface 11 of the optical integrator 4 is preferably 40 ° to 60 °, and more preferably 45 ° to 50 °. By setting the angle formed by the reflecting surface 14 and the light exit surface 11 of the optical integrator 4 within the above range, stable fixation can be realized, and a decrease in light output efficiency can be avoided. If the angle is excessively large, the amount of catching on the optical integrator may be small and the fixation may be insufficient. On the other hand, if the angle is excessively small, the output light may return to the optical integrator and the light output efficiency may decrease. Therefore, neither is preferable. In the present specification, the angle formed by the reflecting surface 14 and the emitting surface 11 passes through a point O on the intersection line L between the reflecting surface 14 and the emitting surface 11 and is on the surface of the reflecting surface 14 and the emitting surface 11, respectively. , L means a straight line M perpendicular to L, and a straight line N, which means an angle between the straight line M and the straight line N.

  In this embodiment, the housing 2 and the reflective housing 13 in which the cylindrical space 5 that accommodates the optical integrator 4 is formed are integrally formed. However, the reflective housing 13 can also be configured as an independent housing. .

DESCRIPTION OF SYMBOLS 1 Optical integrator unit 2 Housing | casing 3 Light source 4 Optical integrator 5 Cylindrical space 6 Optical integrator fixing | fixed part 7 Plate-shaped member 8 Fitting part 9 Recess 10 Incident surface 11 Output surface 12 Side surface 13 Reflective housing 14 Reflective surface

Claims (7)

An optical integrator unit comprising: an optical integrator; a casing having a cylindrical space that houses the optical integrator; and a light source that irradiates light to the optical integrator,
Having an optical integrator fixing part on the light exit surface side of the optical integrator,
An optical integrator unit in which movement of the optical integrator is restricted by the optical integrator fixing portion.   The optical integrator unit according to claim 1, wherein the optical integrator is sandwiched between the optical integrator fixing portion and the light source.   3. The optical integrator unit according to claim 1, wherein the optical integrator fixing portion includes a plate-like member made of a transparent body and a concave portion formed on a wall surface of the casing facing the cylindrical space.   The optical integrator unit according to claim 3, wherein both ends of the concave portion and the plate-like member are fitted.   The optical integrator unit according to claim 3 or 4, wherein the plate-like member is either a lens or a polarizing plate.   The optical integrator fixing portion is formed of a reflective housing having a reflective surface that reflects light emitted from the optical integrator, and the reflective surface and the output surface of the optical integrator are arranged non-parallel. The optical integrator unit according to 2.   The optical integrator unit according to claim 6, wherein the reflective housing and the housing having the cylindrical space are formed of the same housing.