JP2005077840A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact display device which prevents a ghost. <P>SOLUTION: The display device 30 comprises a tabular optical member 5 which is arranged to approximately orthogonally intersect its planes 3a and 3b with an optical axis IP of an optical path of an observation optical system into the optical path and is constituted with an optical waveguide by the planes; an image forming means 7 which is arranged near an end surface 3c of the optical member 5; a polarizing plate 9 which is arranged between the image forming means 7 and the end surface of the optical member 5; a polarization beam splitter 11 which separates the light polarized in a prescribed direction by the polarizing plate 9 of the image light made incident on the interior of the optical member 5 from the image forming means 7; and quarter-wave plate phase plates 40 and 40 which are arranged on the planes 3a and 3b. The display device is constituted to separate the reflected light through the quarter-wave plate phase plates 40 and 40 of the light propagating in the optical member by the polarization beam splitter 11 to a direction differen from the direction of the above separation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display device that enables observation by superimposing an electronic image on an optical image of an observation optical system.

Conventionally, there has been known a display device that can display an electronic image in an optical path of an observation optical system and observe it together with the optical image of the observation optical system. (For example, refer to Patent Document 1).
JP 11-174367 A

  However, since the display device uses the internal reflection of the prism body, there is a possibility that unexpected light such as unnecessary reflected light from the reflection surface of the prism body enters the observation eye and is observed as a ghost. is there.

  The present invention has been made in view of the above problems, and an object thereof is to provide a compact display device that prevents ghosts.

  In order to achieve the above object, in the present invention, a flat plate-like optical element is disposed in an optical path of an observation optical system so that a plane is substantially orthogonal to the optical axis of the optical path, and an optical waveguide is constituted by the plane. A member, an image forming unit disposed in the vicinity of an end surface portion of the optical member, a polarizing plate disposed between the image forming unit and an end surface of the optical member, and an inside of the optical member from the image forming unit A polarizing beam splitter that separates a light beam polarized in a predetermined direction by the polarizing plate, and a light beam that propagates through the optical member. The display device is characterized in that the reflected light through the quarter-wave phase plate is separated in a direction different from the separation direction by the polarization beam splitter.

  In the present invention, a flat optical member that is disposed in the optical path of the observation optical system so that a plane is substantially orthogonal to the optical axis of the optical path, and forms an optical waveguide by the plane, and the optical member An image forming unit disposed in the vicinity of an end surface portion of the optical member, a reflecting member that reflects an image light beam incident from the image forming unit into the optical member toward the observation optical system, and the plane. A light control member that transmits a light beam incident substantially perpendicularly to the plane and reflects the light beam incident on the plane at a predetermined angle in a direction different from the incident direction, and the plane out of the light beams propagating through the optical member. The display device is characterized in that the light beam traveling in the direction of is separated in a direction different from that of the reflecting member by the light control member.

  Further, in the present invention, a planar plate-like optical member forming an optical waveguide, and a polarizing beam splitter that is formed inside the optical member and reflects a light beam polarized in a predetermined direction among light beams propagating through the optical member. And a quarter-wave phase plate disposed on the surface of the optical member, and the reflected light that has passed through the quarter-wave phase plate out of the light beam propagating through the optical member is transmitted through the polarization beam splitter. A display device is provided.

  Further, in the present invention, a planar plate-like optical member that forms an optical waveguide, and a polarizing beam splitter that is formed inside the optical member and transmits a light beam polarized in a predetermined direction among light beams that propagate through the optical member. And a quarter-wave phase plate disposed on the surface of the optical member, and reflects the reflected light through the quarter-wave phase plate out of the light beam propagating through the optical member by reflecting the polarization beam splitter. A display device is provided.

  Further, in the present invention, a planar plate-like optical member that forms an optical waveguide, and a polarization beam splitter that is formed inside the optical member and separates a light beam that is polarized in a predetermined direction among light beams that propagate through the optical member. And a quarter-wave phase plate disposed on the surface of the optical member, and the reflected light that has passed through the quarter-wave phase plate out of the light beam propagating through the optical member is reflected by the polarizing beam splitter. Provided is a display device which is separated in a direction different from the separation direction.

  The present invention can provide a compact display device that prevents ghosts.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a display device according to a first embodiment of the present invention. FIG. 2 shows an example of the rubbing direction of the quarter-wave phase plate in the first embodiment. FIG. 3 shows an example of an optical member provided with the quarter-wave phase plate in the first embodiment. FIG. 4 is a schematic configuration diagram of a display device according to the second embodiment of the present invention. FIG. 5 is a schematic configuration diagram of a display device according to the third embodiment of the present invention.

(First embodiment)
In FIG. 1, an optical image (not shown) is incident along the optical axis IP of the observation optical system and is observed by the photographer at an eye point EP. A light superimposing optical system 1 for displaying an electronic image superimposed on the optical image is inserted in the optical path of the observation optical system. The light superimposing optical system 1 is composed of an optical member 5 constituting an optical waveguide composed of a pair of planes 3a, 3b substantially perpendicular to the optical axis IP of the observation optical system and a plane 3c substantially perpendicular to the planes 3a, 3b. ing. A display member 7 that is an image forming means for displaying an electronic image is disposed in the vicinity of the plane 3c, and a polarizing plate 9 is provided between the display member 7 and the plane 3c.

  The light superimposing optical system 1 is provided with a polarization beam splitter (hereinafter referred to as PBS) 11 having an inclination of about 45 degrees with respect to the optical axis IP of the observation optical system and the optical axis IS of the display light. The polarized light is reflected in the direction opposite to the observation eye 13. The reflected light is incident on and transmitted to the quarter-wave phase plate 15 disposed in the optical path of the observation optical system on the plane 3a that is the incident surface of the optical image, and is incident on the reflective condensing member 17. Reflected to the PBS 11 side. The quarter-wave plate and the reflection condensing member 17 are made of a member that is substantially transparent to the light in the optical path of the observation optical system, and the optical image is hardly deteriorated. The light returned to the PBS 11 side is rotated in the polarization direction as described later, passes through the PBS 11, and is observed at the eye point EP. In this way, the display device 30 is configured that enables observation by superimposing the display image from the display member 7 on the optical image from the observation optical system. The optical axis IP of the observation optical system and the optical axis IS of the display optical system are configured to be substantially orthogonal.

  Light from an electronic image (hereinafter also referred to as a display image) displayed on the display member 7 is polarized in a predetermined direction (for example, P-polarized component) by the polarizing plate 9 and enters the optical member 5 from the plane 3c. . The incident light travels along the optical axis IS of the display optical system, is reflected by the PBS 11 provided in the light superimposing optical system 1 (for example, a P-polarized component), and is a plane in the direction opposite to the observation eye 13. Proceed to the reflection / condensing member 17 (hereinafter referred to as a “hologram” as a representative) to which the ¼ wavelength phase plate 15 and the hologram or wavelength selection film are attached. The light that has passed through the ¼ wavelength phase plate 15 is converted into circularly polarized light, reflected by the hologram 17, and transmitted through the ¼ wavelength phase plate 15 again to be converted into linearly polarized light. Since this light is reflected by the PBS 11 and incident on the hologram 17 is converted into linearly polarized light whose polarization direction is rotated by 90 degrees, the light passes through the PBS 11 and exits from the light superimposing optical system 1 to be converted into an eye point. EP forms an image on the viewer's retina.

  Further, in the first embodiment, the quarter-wave phase plates 40 and 40 are provided on almost the entire surface on the planes 3a and 3b substantially perpendicular to the optical axis of the observation optical system IP of the optical member 5 that is an optical waveguide. . The quarter-wave phase plates 40, 40 are phases of light (for example, indicated by a solid line G1 in the figure) that is emitted from the display member 7 and is incident on the planes 3a, 3b of the optical member 5 and reflected at the interface with air. In this configuration, the reflected light (light of the display image) from the PBS 11 incident on the planes 3a and 3b substantially perpendicularly is not affected at all. As a result, the light G1 that is incident on the planes 3a and 3b, is reflected at the interface with the air, and exits is rotated by 90 degrees with respect to the incident light. For example, light polarized to P-polarized light by the polarizing plate 9 is incident on the plane 3a, reflected at the interface with air, and emitted, and converted to S-polarized light whose polarization direction is rotated by 90 degrees. Since the PBS 11 is designed to reflect the light of the P-polarized component, the light incident on the planes 3a and 3b and reflected and emitted passes through the PBS 11, and is reflected by the PBS 11 to enter and reflect on the hologram 17. Thus, the observation eye 13 is not reached. The light transmitted through the PBS 11 is emitted from the flat surface 3d of the optical member 5. Note that a light absorbing member may be provided on the flat surface 3d so that incident light is absorbed.

  Thus, according to the first embodiment, ghost light (that is incident on the observation eye 13 after being incident on the planes 3a and 3b of the optical superposition optical system 1 that is an optical waveguide, reflected and emitted from the interface with air) For example, G1) can be prevented.

  Next, the quarter wavelength phase plates 40 and 40 formed on the planes 3a and 3b will be described. FIG. 2 shows a schematic view seen from the direction of the eye point EP of FIG. Here, the case where the quarter-wave phase plate 40 is formed on the plane 3a will be described, and the plane 3b is the same and will not be described.

  2 and 3, the flat surface 3a is subjected to a rubbing process used in a liquid crystal manufacturing process in a direction of approximately 45 degrees (in the direction of the arrow in the drawing) with respect to the optical axis IS of the display optical system. Thereby, minute unevenness | corrugation thru | or a groove | channel are formed in the predetermined | prescribed direction (arrow direction) on the surface of the plane 3a. The ultraviolet curable liquid crystal 21 is applied to a predetermined thickness on the surface thus treated. The coating operation is performed with a so-called spin coater. The thickness of the ultraviolet curable liquid crystal 21 is set to a thickness having an optical path difference that rotates the phase of the light that becomes the assumed ghost light by approximately 90 degrees.

  The ultraviolet curable liquid crystal 21 applied by the spin coater has liquid crystal molecules regularly aligned along the direction of the rubbing 19 and exhibits a predetermined optical anisotropy. Thereafter, the ultraviolet curable liquid crystal 21 is cured by irradiating ultraviolet rays, and is fixed to the surface of the flat surface 3 a as a quarter wavelength phase plate 40. Similarly, the quarter-wave phase plate 40 is also formed on the surface of the plane 3b.

  The quarter-wave phase plate 40 is not limited to the above-described ultraviolet curable liquid crystal 21, but a quarter-wave phase plate film or a quarter-wave phase crystal plate that generates a predetermined phase difference is formed on the planes 3a and 3b. It may be formed by being attached to the entire surface of the film. Moreover, you may provide only in any one of plane 3a, 3b. How to provide the quarter-wave phase plate 40 may be determined depending on the generation state of ghost light.

(Second Embodiment)
Next, a display device according to a second embodiment of the present invention will be described. The difference between the second embodiment and the first embodiment is that the quarter-wave phase plate 15 that forms a display image on the retina of the observation eye and the position where the hologram 17 is arranged are different. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 3, the light from the display member 7 is polarized in a predetermined direction (for example, P-polarized light) by the polarizing plate 9 and enters from the plane 3c of the optical member 5 that is an optical waveguide. The incident light travels along the optical axis IS of the display optical system, passes through the PBS 11 arranged in the light superimposing optical system 1, and exits from the plane 3d facing the plane 3c. 15 is incident and transmitted to the hologram 17 and reflected and returned to the PBS 11 direction. Since the returned light is rotated by about 90 degrees in the polarization direction by the ¼ wavelength phase plate 15, it is reflected by the PBS 11 and enters the observation eye 13 and forms an image at the eye point EP. As a result, the display image of the display member 7 and the optical image of the observation optical system IP can be observed by being superimposed at the eye point EP. In this way, the display device 35 is configured.

  In the second embodiment, quarter-wave phase plates 40 and 40 are disposed on the two flat surfaces 3a and 3b of the optical member 5 as in the first embodiment. Of the light from the display member 7, the light (for example, the solid line G <b> 1 in the figure) that is incident on the planes 3 a and 3 b and is reflected at the interface with the air is rotated by approximately 90 degrees in the polarization direction by the quarter wavelength phase plate 40. Therefore, it is reflected by the PBS 11 and is emitted from the optical member 5 and does not enter the hologram 17. As a result, it is possible to prevent G1 that is ghost light from entering the observation eye 13.

  Of the display light that passes through the PBS 11 and enters the hologram 17, the light that enters the planes 3 a and 3 b due to the irregular reflection of the quarter-wave phase plate 15 and the hologram 17 (for example, the solid line G2 in the figure) Since the polarization direction is rotated by approximately 90 degrees by the quarter wavelength phase plate 40 and transmitted through the PBS 11, it is not emitted to the observation eye 13 side.

  As described above, in the display device 30 according to the second embodiment, the ¼ wavelength phase plates 40 and 40 are arranged on the planes 3 a and 3 b of the parallel plane optical member 14, so that G1 and G2 that are ghost lights can be obtained. It is possible to prevent the light from entering the observation eye 13.

  Note that the configuration of the quarter-wave phase plates 40 and 40 is the same as that of the first embodiment, and a description thereof will be omitted. Further, the quarter-wave phase plates 40 and 40 may be formed on both or one of the flat surfaces 3a and 3b, but how to form the quarter-wave phase plates 40 and 40 may be determined depending on the generation state of ghost light.

(Third embodiment)
Next, a display device according to a third embodiment of the present invention will be described. The difference between the third embodiment and the first and second embodiments is that the quarter-wave phase plate 40 is changed to a light control member. Other configurations are the same as those of the first and second embodiments, and the same reference numerals are given and the description thereof is omitted.

  In FIG. 5, in the third embodiment, the display device 50 is configured by arranging light control members 25, 25 on two planes 3 a, 3 b of the optical member 14.

  The light control member 25 is configured to transmit light that is incident on the plane 3a substantially perpendicularly, and to block light that is incident at a predetermined incident angle or more (for example, an optical with a built-in microlouver manufactured by Sumitomo 3M Limited). Filter may be used). With such a configuration, the light that is ghost light (for example, G1 in the figure) that is incident on the planes 3a and 3b with the light from the display member 7 is blocked by the light control member 25. It is possible to prevent the light from being reflected and emitted from the light superimposing optical system 1 through the quarter-wave phase plate 15 and the hologram 17 to form an image on the observation eye 13.

  It should be noted that whether the light control member 25 is provided on both of the flat surfaces 3a and 3b or only one of them may be appropriately determined depending on the generation state of ghost light.

  The above-described embodiment is merely an example, and is not limited to the above-described configuration and shape, and can be appropriately modified and changed within the scope of the present invention. For example, in the first embodiment, the PBS 11 may be arranged so that the display light reflected by the PBS 11 is directly reflected to the eye point EP side, and the quarter wavelength plate 15 and the hologram 17 may not be provided. It is.

1 is a schematic configuration diagram of a display device according to a first embodiment of the present invention. An example of the rubbing direction of the quarter wavelength phase plate in 1st Embodiment is shown. An example of the optical member provided with the quarter wavelength phase plate in 1st Embodiment is shown. The schematic block diagram of the display apparatus concerning 2nd Embodiment of this invention is shown. The schematic block diagram of the display apparatus concerning 3rd Embodiment of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light superposition optical system 3 Plane 5 Optical member 7 Display member 9 Polarizing plate 11 Polarizing beam splitter (PBS)
13 Observation Eye 15 1/4 Wave Phase Plate 17 Reflecting and Condensing Member (Hologram)
21 UV-curable liquid crystal 25 Light control member 30, 35, 50 Display device 40 1/4 wavelength phase plate IP Optical axis of observation optical system IS Optical axis of display optical system EP Eyepoint

Claims (5)

In the optical path of the observation optical system, a flat optical member that is disposed so that a plane is substantially orthogonal to the optical axis of the optical path, and forms an optical waveguide by the plane;
An image forming means disposed in the vicinity of the end face of the optical member;
A polarizing plate disposed between the image forming means and the end face of the optical member;
A polarizing beam splitter that separates a light beam polarized in a predetermined direction by the polarizing plate, out of the image light beam incident on the inside of the optical member from the image forming unit;
A quarter wavelength phase plate disposed in the plane,
A display device, wherein light reflected through the ¼ wavelength phase plate among light beams propagating through the optical member is separated in a direction different from the separation direction by the polarization beam splitter. In the optical path of the observation optical system, a flat optical member that is disposed so that a plane is substantially orthogonal to the optical axis of the optical path, and forms an optical waveguide by the plane;
An image forming means disposed in the vicinity of the end face of the optical member;
A reflecting member that reflects an image light beam incident on the inside of the optical member from the image forming unit toward the observation optical system;
A light control member that is disposed on the plane and transmits a light beam incident substantially perpendicular to the plane and reflects the light beam incident on the plane at a predetermined angle in a direction different from the incident direction;
A display device, wherein a light beam traveling in the direction of the plane among light beams propagating through the optical member is separated in a direction different from the reflecting member by the light control member. A planar plate-shaped optical member forming an optical waveguide;
A polarization beam splitter that is formed inside the optical member and reflects a light beam polarized in a predetermined direction among light beams propagating through the optical member;
A quarter-wave phase plate disposed on the surface of the optical member,
A display device, wherein light reflected through the ¼ wavelength phase plate among light beams propagating through the optical member is transmitted through a polarizing beam splitter. A planar plate-shaped optical member forming an optical waveguide;
A polarizing beam splitter that is formed inside the optical member and transmits a light beam polarized in a predetermined direction among light beams propagating through the optical member;
A quarter-wave phase plate disposed on the surface of the optical member,
A display device, wherein the polarized beam splitter reflects the reflected light that has passed through the ¼ wavelength phase plate out of the light flux propagating through the optical member. A planar plate-shaped optical member forming an optical waveguide;
A polarization beam splitter that is formed inside the optical member and separates a light beam polarized in a predetermined direction among light beams propagating through the optical member;
A quarter-wave phase plate disposed on the surface of the optical member,
A display device, wherein light reflected through the ¼ wavelength phase plate among light beams propagating through the optical member is separated in a direction different from the separation direction by the polarization beam splitter.

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