Projection-type image display device and spatial light modulator lighting method

Abstract

The invention discloses a projection-type image display device and a spatial light modulator lighting method. A laser beam (L50) generated by a laser source is reflected by a beam shooting device (65) and irradiates on hologram recording media (46, 85). In the hologram recording media (46, 85), reference light formed by parallel beams is used for recording an image (35) of a scattering plate to be a hologram. The beam shooting device enables the irradiation position of a beam (L65) on the hologram recording media (46, 85) to change along with time. The spatial light modulator (200) is configured to be at a generation position of a reconstructed image (35) for the scattering plate (30) obtained by the hologram recording media (46, 85). Diffraction light (L46) from the hologram recording media (46, 85) directly irradiates on the spatial light modulator (200) via no any optical system. The beam shooting device (65) enables the beam (L65) to irradiate on the hologram recording media (46, 85) from a direction parallel to the reference light (Lref) for shooting of the laser beam (L65).

Description

[0001] This application is a divisional application of a patent application with an application date of September 7, 2010, an application number of 201080069008.3, and an invention title of "projection-type image display device", the entire contents of which are hereby incorporated by reference. technical field [0002] The present invention relates to a projection type image display device, in particular to the technique of using light from a coherent light source to illuminate a spatial light modulator to display images on a screen. Background technique [0003] Various types of projection type image display devices including a commercially available one called a so-called "optical projector" have been proposed for projecting light onto a screen to display an image. The basic principle of this projection type image display device is to use a liquid crystal microdisplay or a spatial light modulator such as a DMD (Digital Micromirror Device) to generate a basic two-dimensiona...

AI Technical Summary

Problems solved by technology

[0010] However, rotating and vibrating the diffusion plate requires a large-scale mechanical drive mechanism, which increases the overall size of the device and increases power consumption.

Also, in this method, since the light from the laser light source is scattered by the diffuser plate, a part of the laser light does not contribute to image display at all and is wasted.

In addition, even if the diffusion plate is rotated and vibrated, the position of the optical axis of the illumination light does not change, so it is impossible to sufficiently suppress the occurrence of spots on the diffusion surface of the screen.

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