Minolta Company, Ltd.

Konica-minolta Holdings, Inc.

Konica Minolta Photo Imaging, Inc.

Konica Minolta Opto, Inc.

Tetsuya Noda

Yasushi Tanijiri

Takeshi Endo

Ichiro Kasai

Hiroaki Ueda

Yoshie Shimizu

Kenji Ishibashi

Yasushi Kobayashi

Hiroshi Hatano

Takashi Morimoto

Hiroyuki Matsuda

Kazutaka Noguchi

Hiroshi Yamaguchi

Shigeru Yamasaki

The light directed from a light source to a concave mirror and the light directed from a display device to an eyepiece optical system are intersected by each other in a layout. This allows the light source, the concave mirror, and the display device to be arranged in compactness adjacent to the eyepiece optical system without increasing the optical power of an illumination optical system. As the result, the apparatus can easily be minimized in the thickness or the overall size. A hologram optical element is provided where the relationship between the wavelength range &#x394;&#x3bb;at half of the diffraction efficiency of each of the three primary colors of the light in the hologram optical element and the wavelength range &#x394;&#x3bb;at half of the intensity of each of the three primary colors of the light emitted from the light source is defined by &#x394;&#x3bb;. Accordingly, a component at desired wavelengths of each of the R, G, and B colors of the light emitted from the light source can be diffracted by the action of the hologram optical element and then directed to the pupil of the viewer. This allows the image to be increased in the color reproduction area and improved in the quality regardless of the display device actuated in a time-division mode.

Image display apparatus and head mount display

An optical information recording and reproducing apparatus relating to the invention employs a two-beam interference method. In the optical information recording and reproducing apparatus, a moving device moves an information recording medium between a recording and reproducing position and a retracting position, and a mirror moves together with the information recording medium. When the information recording medium moves to the recording and reproducing position, the mirror moves to a position which is displaced from the at least one of the reference beam and the information beam. When the information recording medium moves to the retracting position, the mirror moves to a position where the mirror can reflect the at least one of the reference beam and the information beam toward a detector for detecting a deviation of the at least one of the reference beam and the information beam.

Optical information recording and reproducing apparatus, and cartridge

Variation of the wavelength of the light emitted from a light source is reduced by a wavelength variation reduction mechanism. Hence, wavelength deviation of the intensity peak of the light emitted from the light source from the diffraction-efficiency peak of a hologram optical element is reduced. Thus, even when a high-brightness light source is used, the light emitted therefrom can be diffracted with the hologram optical element efficiently. Moreover, the heat generated by the light source is efficiently rejected through the surface of a land portion of a flexible printed circuit, is then, via an insulating layer of the flexible printed circuit, efficiently absorbed through the surface of a heat absorbing member, and is then, via a shield conductor, led out of a casing, so as to be thereby expelled.

Image display apparatus and head-mounted display

A hologram optical element is formed on a substrate so as to make an optical device. The hologram optical element is formed in an area smaller than an irradiation area of a beam for reproduction such as image light or object light on the substrate. Supposing that the beam for reproduction is made of a center beam having intensity higher than 50% of center intensity and other peripheral beam, the hologram optical element is formed on the substrate in a size for diffracting only the center beam so that a flare or a ghost can be relieved without using additional optical elements such as a shading plate.

Optical holographic device with a hologram optical element on an area smaller than an irradiation area, holographic image display device and head mounted display with a hologram optical element on an area smaller than an irradiation area

In a joined optical member, let the adhesion strength between a surface coating layer and an eyepiece prism be A, the adhesion strength between the surface coating layer and a deflector prism be A, the adhesion strength between the surface coating layer and adhesive be A, and the adhesion strength between, at one end, the adhesive and, at the other, the eyepiece prism and the deflector prism be A, then A(A)&#x3e;Aand simultaneously AA. This makes removal of superfluous adhesive on the surface coating layer easy, and prevents scratches on the exterior surfaces. Even after removal of superfluous adhesive, the surface coating layer remains on the exterior surfaces of the eyepiece prism and the deflector prism. This prevents scratches on the exterior surfaces in actual use, and prevents degradation of optical performance.

Joined optical member, image display apparatus, and head-mounted display

The exposure amounts of R, G, and B laser light emitted from a fabrication light source are so adjusted that the diffraction efficiency at R, G, and B wavelengths in an optical element is commensurate with the light intensity at the R, G, and B wavelengths in the light emitted from a reproduction light source. For example, when the light intensity of the light emitted from the reproduction light source is increasingly low at the B, G, and R wavelengths in this order, the exposure amounts of the R, G, B, laser light emitted from the fabrication light source are so adjusted that the diffraction efficiency in the optical element is increasingly high at the B, G, and R wavelengths in this order. In this way, the hue of the light (reproduction light) obtained from the reproduction light source via the optical element can be adjusted to the hue desired with every reproduction light source used, while the most use is made of the light emitted from the reproduction light source actually used.

Method for producing an optical device, optical device, image display apparatus, and head-mounted display

An image display apparatus has: a display element for displaying an image; a light source section for supplying an illumination light to the display element; a reflection type hologram for diffracting and reflecting the illumination light so as to guide the illumination light to the display element; and an eyepiece optical system for guiding an image light from the display element to an eye of a viewer so as to provide an enlarged virtual image of the image. The reflection type hologram has diffusing properties. Since the reflection type hologram diffuses the illumination light, an incident angle of the illumination light with respect to the display element is widened to a certain extent. Since the display element does not change a propagating direction of a light ray, a propagating direction of the image light is widened similarly to widening of the incident angle, thereby enlarging the observation pupil.

Image display apparatus

A band-pass filter has a reflecting optical element having a fixed reflection angle selection region for wavelengths of a given region, and has an optical path such that reflection is performed at least once and transmission is performed at least once at the reflecting optical element.

Band-pass filter and image display apparatus

An image display apparatus has an image display device for displaying an image, an eyepiece optical system, including a holographic magnifying optical element, for magnifying and projecting the image, and a holographic filter, disposed either as part of the image display device or in the optical path between the image display device and the eyepiece optical system, for restricting the wavelength range of the image light.

A holographic element is a reflective holographic element formed on a substrate and constituted by a composite hologram having a plurality of patterns of interference fringes composed of interference fringes nonparallel to the substrate. The holographic element forms, out of image light having a predetermined wavelength width emanating from an image display element, a plurality of observation pupils at spatially different locations, and acts in such a way as to fulfill prescribed conditions for an identical incident ray over the entire area in which the image light is incident on the holographic element.

An image display apparatus has a display section for displaying an image, an eyepiece optical system, and a transparent plate-shaped member for holding the eyepiece optical system. The image display apparatus is used with the eyepiece optical system placed in front of a viewer's eyes and with the plate-shaped member facing the eyes. The image display apparatus directs light from the display section through the eyepiece optical system to the eyes so that the viewer is presented with a virtual image of the image displayed on the display section and simultaneously permits light from the outside world to be transmitted through the plate-shaped member so as to be directed to the eyes so that the viewer is presented with an image of the outside world. The boundary surface between the eyepiece optical system and the plate-shaped member is so arranged as not to reflect light from the outside world incident thereon at angles of incidence greater than the Brewster angle toward the eyes.

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Tenri, Japan

Tetsuya Noda