JP4725004B2 - Display device - Google Patents

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.

To achieve the above object, the present invention provides a first planar surface substantially perpendicular to the pair to the optical axis of the observation optical system and a second planar surface, substantially in the first plane and the second plane a third plane and the fourth plane and the optical engine material that make up the optical waveguide comprising a formed across the optical axis in the vertical, front SL between the first planar surface and the second flat surface the arranged and the polarization beam splitter disposed to be inclined approximately 45 degrees, the first and the second flat surface and the quarter-wave phase plate disposed in a first plane to the optical axis between and a second quarter wave plate, the third image forming means are arranged in a plane near a polarizing plate arranged between the third plane and said image forming means, said fourth A reflective condensing member disposed in the vicinity of a plane; and a third quarter-wave phase plate disposed between the reflective condensing member and the fourth plane ;
Light emitted from the image forming unit along the optical axis of the image forming unit substantially perpendicular to the optical axis passes through the polarizing plate and enters the optical member. polarized in the polarization beam splitter transmitting to the incident on the reflection condensing member passes through the third quarter wave plate, the reflecting condensing member with being reflected the third 1 / It passes through a four-wavelength phase plate, is polarized in a direction different from the predetermined direction by 90 ° by the third quarter-wavelength phase plate, is reflected by the polarization beam splitter , and is reflected by the second quarter-wavelength phase. Light that passes through the plate, reaches the eye point along the optical axis of the observation optical system, is emitted from the image forming means, and is reflected by the first quarter-wave phase plate is transmitted through the polarizing beam splitter. And reflected from the third quarter-wave phase plate Light reflected by the second quarter wave plate out, the passes through the beam splitter, said the eye point to provide a display device comprising Rukoto such undelivered.

Further, the present invention includes a first flat surface substantially perpendicular to the pair to the optical axis of the observation optical system and a second planar surface, the first plane and the second substantially vertical third plane to the plane a polarization beam splitter disposed to be inclined approximately 45 degrees to the optical axis between the optical engine material that make up the optical waveguide, the previous SL first planar surface and the second flat surface consisting of, first and second light control member and the light control member disposed in said second planar surface of said third image forming means are arranged in a plane near which is disposed on the first planar surface, a polarizing plate arranged between the third plane and said image forming means, said first reflecting condensing member disposed on the optical axis of the light control member near the front Symbol first light control A quarter-wave phase plate disposed between the member and the reflective condensing member,
The first light control member and the second light control member are optical filters that shield a light beam incident on the light control member at an angle equal to or greater than a predetermined angle, and the light from the image forming unit. Light emitted along the optical axis of the image forming unit substantially perpendicular to the axis passes through the polarizing plate and enters the optical member, and is polarized in a predetermined direction by the polarizing plate, and the polarized beam. the reflected and collected after passing through the quarter-wave plate through the first pre-Symbol light control member is reflected in the direction of the first flat surface along the optical axis of the observation optical system by the splitter incident on the light member, wherein the predetermined direction is polarized in the 90 ° direction different the reflected and collected by the optical member anti Isa is through said second quarter-wave plate by the quarter wave plate The first light control member and the polarization beam splitter; Transmitted through the serial second light control member, the observed along the optical injection reaches the eye point, light incident at said predetermined angle or more angles to the light control member is emitted from the image forming means provides a display device comprising Rukoto such as Futachi the eye point is shielded by the light control member.

  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 includes an optical member 5 that forms an optical waveguide including a pair of planes 3a and 3b substantially perpendicular to the optical axis IP of the observation optical system and a plane 3c substantially perpendicular to the planes 3a and 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 approximately 45 degrees with respect to the optical axis IP of the observation optical system and the optical axis IS of the display light, and is provided in a predetermined direction. 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 and 40 are phases of light emitted from the display member 7 and incident on the planes 3a and 3b of the optical member 5 and reflected at the interface with air (for example, indicated by a solid line G1 in the figure). 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 that is reflected and emitted after entering the planes 3a and 3b passes through the PBS 11, and is reflected by the PBS 11 to enter and reflect 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. 4 , 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 3 c 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, the 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 ¼ 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 G <b> 2 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 35 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 5 , so that G1 and G2 which 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)

The first flat surface substantially perpendicular to the pair to the optical axis of the observation optical system and a second planar surface, the formed substantially across the optical axis perpendicular to said first plane and said second plane 3 planes and the optical Faculty material that make up the optical waveguide comprising a fourth plane,
A polarization beam splitter disposed to be inclined approximately 45 degrees to the optical axis between the front Symbol first planar surface and the second flat surface,
A second quarter wave plate arranged on the first and the second flat surface and the quarter-wave phase plate disposed in a first plane,
Image forming means disposed in the vicinity of the third plane ;
A polarizing plate disposed between the image forming means and the third plane ;
A reflecting condensing member arranged in a plane near the fourth,
A third quarter-wave phase plate disposed between the reflective condensing member and the fourth plane ;
Light emitted from the image forming unit along the optical axis of the image forming unit substantially perpendicular to the optical axis passes through the polarizing plate and enters the optical member. polarized in the polarization beam splitter transmitting to the incident on the reflection condensing member passes through the third quarter wave plate, the reflecting condensing member with being reflected the third 1 / It passes through a four-wavelength phase plate, is polarized in a direction different from the predetermined direction by 90 ° by the third quarter-wavelength phase plate, is reflected by the polarization beam splitter , and is reflected by the second quarter-wavelength phase. Transmits through the plate, reaches the eye point along the optical axis of the observation optical system,
The light emitted from the image forming means and reflected by the first quarter-wave phase plate is reflected by the polarization beam splitter, emitted from the third quarter-wave phase plate, and the second the light reflected by the quarter wave plate, transmitted through the beam splitter, said the eye point display device comprising Rukoto such undelivered. Said first and said second quarter wave plate, the first flat surface and the second planar surface, forming a substantially 45 ° direction with respect to the optical axis of the light beam from said image forming means The display device according to claim 1, wherein the display device is configured to have a minute unevenness or groove formed, and an ultraviolet curable liquid crystal is applied to the surface of the minute unevenness or groove with a predetermined thickness. The first flat surface substantially perpendicular to the pair to the optical axis of the observation optical system and a second planar surface, an optical waveguide consisting of said first plane and said second substantially vertical third plane to the plane and light Faculty of material that make up,
A polarization beam splitter disposed to be inclined approximately 45 degrees to the optical axis between the front Symbol first planar surface and the second flat surface,
A second light control member disposed on the first of the light control member second planar surface disposed on a first flat surface,
Image forming means disposed in the vicinity of the third plane ;
A polarizing plate disposed between the image forming means and the third plane ;
A reflective condensing member disposed on the optical axis in the vicinity of the first light control member;
And a quarter wave plate disposed between the front Symbol first light control member and the reflective condensing member,
The first light control member and the second light control member are optical filters that shield a light beam incident at a predetermined angle or more among light beams incident on the light control member,
Light emitted from the image forming unit along the optical axis of the image forming unit substantially perpendicular to the optical axis passes through the polarizing plate and enters the optical member. polarized in the quarter-wave plate through the first pre-Symbol light control member is reflected in the direction of the first flat surface along the optical axis of the observation optical system by the polarization beam splitter incident on the reflection condensing member passes through the said by the quarter wave plate the reflected and condensed by the optical member anti Isa been through the first quarter wave plate to the predetermined direction 90 ° polarized in different directions, transmitted through the first light control member, the polarization beam splitter and the second light control member, exited along the observation optical system and reached the eye point,
It said light incident at a predetermined angle or more angles, the display device according to claim Rukoto such as Futachi the eye point is shielded by the light control member on the light control member is emitted from the image forming means. The reflection condensing member A display device according to any one of claims 1 to 3, characterized in that it is constituted by a hologram. The polarization beam splitter, any one of claims 1-4, characterized in that emitted from the light from the first planar surface and the second flat surface overlap with the real image incident from from the image forming means Item 1. A display device according to item 1.

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