Image displaying apparatus and optical Apparatus

Abstract

The image displaying apparatus includes an image production apparatus, a first light conduction section and a second light conduction section. The first light conduction section includes a first light conduction plate which propagates part of incident light thereto by total reflection in the inside thereof and emits the propagated light, and a reflection type volume hologram diffraction grating disposed on the first light conduction plate. The second light conduction section includes a second light conduction plate, a first deflection section and a second deflection section.

Description

BACKGROUND OF THE INVENTION[0001] 1. Field of the Invention[0002] This invention relates to an optical apparatus and an image displaying apparatus in which the optical apparatus is incorporated.[0003] 2. Description of the Related Art[0004] A virtual image displaying apparatus as an image displaying apparatus wherein a virtual image optical system allows a two-dimensional image formed by an image formation apparatus to be observed as an enlarged virtual image by an observer is well known, for example, from JP-T-2005-521099 and Japanese Patent Laid-Open No. 2006-162767.[0005] As conceptually illustrated in FIG. 25, the image displaying apparatus 900 mentioned includes an image formation apparatus 911 including a plurality of pixels arranged in a two-dimensional matrix, a collimate optical system 912 for converting light emitted from the pixels of the image formation apparatus 911 into parallel light and a light conduction section 930 for receiving, conducting and emitting the paralle...

AI Technical Summary

Benefits of technology

[0009] In the image displaying apparatus 1000 shown in FIGS. 26 and 27, a leftward and rightward, that is, horizontal, direction and an upward and downward, that is, vertical, direction are defined as a Y direction and a Z direction, respectively. In particular, image displaying light for displaying an image, various kinds of information and so forth is conducted from a transverse direction to the pupil 41 of an observer and enters the pupil 41. It is to be noted that, where the image displaying apparatus 1000 is applied to a head-mounted type display (HMD) unit, the image formation apparatus and so forth are disposed not above the pupil 41 but in a transverse direction with respect to the pupil 41 so that good observation of the external world can be implemented.

[0018] Accordingly, it is desirable to provide an image displaying apparatus which allows an observer to observe a two-dimensional image formed by an image formation apparatus as an enlarged virtual image by means of a virtual image optical system and wherein there is no necessity to use a lens of a large diameter in the image formation apparatus and an optical apparatus suitable to incorporate in the image displaying apparatus.

[0078] In the image displaying apparatus and the optical apparatus according to the first mode of the present invention, the first light conduction section is disposed between the image production apparatus and the second light conduction section and is configured from the first light conduction plate and the reflection type volume hologram diffraction grating. Accordingly, the first light conduction section functions as a kind of beam expander, that is, as a kind of beam expansion means, and the shape of a light flux emitted from the image production apparatus and introduced into the first light conduction section is expanded along the light propagation direction by the internal total reflection in the first light conduction plate by the reflection type volume hologram diffraction grating. Then, the light flux of the expanded form is introduced into the second light conduction section. On the other hand, the image displaying apparatus and the optical apparatus according to the second mode of the present invention include the beam expansion section for expanding light or a light flux in the Z direction and introducing the expanded light or light flux to the light conduction section. Therefore, the necessity for setting the diameter of the aperture stop in the Z direction of the image production apparatus to a large diameter is eliminated, and the necessity to use a lens of a large diameter in the image production apparatus is eliminated. Consequently, reduction in size and weight of the image displaying apparatus can be anticipated, and such a situation that the display contrast drops and the picture quality is deteriorated is prevented. Further, while the first light conduction section is formed from the reflection type volume hologram diffraction grating, since interference fringes formed on the reflection type volume hologram diffraction grating have a uniform angle and exhibit uniform refractive index modulation over the entirety thereof, there is no necessity for alignment which is difficult and a dispersion is less likely to occur.

Problems solved by technology

On the other hand, with such a configuration as described above, since the propagation distance of the light conducted in the inside of the light conduction plate 1031 becomes comparatively long, a problem given below appears.

Images