Unlock instant, AI-driven research and patent intelligence for your innovation.

Optical system for image projection and image projection apparatus

An optical system and image projection technology, which is applied in the field of optical systems, can solve the problems of actual light reduction and efficiency reduction, and achieve the effect of improving contrast and suppressing light reduction

Inactive Publication Date: 2007-12-12
CANON KK
View PDF3 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At the lens array generating a plurality of light fluxes for overlappingly irradiating the image forming element, and at the polarization conversion element converting unpolarized light from the light source into predetermined linearly polarized light, an increase in the angle of the light flux leads to a decrease in efficiency, which cause the actual amount of light to decrease

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Optical system for image projection and image projection apparatus
  • Optical system for image projection and image projection apparatus
  • Optical system for image projection and image projection apparatus

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] 1 and 2 show the configuration of an optical system for image projection as Embodiment 1 of the present invention. In this embodiment, Oc represents the optical axis of the condenser lens 6 . Optical axis Oc is also an axis (or optical axis) passing through the center of condensing lens 6 and the center of the incident / exit surface (hereinafter simply referred to as panel surface) of reflective liquid crystal panel 8 as a reflective image forming element.

[0037] The direction along the optical axis Oc is also called the light traveling direction (or z-axis direction), and in this direction, the luminous flux from the light source lamp LP travels toward the reflective liquid crystal panel 8 through the condenser lens 6 and the polarizing beam splitter 7 .

[0038] Fig. 1 shows the optical configuration in the xz section (first section), wherein in the xz section and the yz section (second section) each including the optical axis Oc of the condenser lens 6, the xz secti...

Embodiment 2

[0104] 9 and 10 show the configuration of an optical system for image projection as Embodiment 2 of the present invention. This embodiment corresponds to an optical system in which an anamorphic light flux compression system is provided in the illumination optical system of Embodiment 1.

[0105] In this embodiment, the same elements as those described in Embodiment 1 are assigned the same reference numerals.

[0106] In this embodiment, the convex cylindrical lens 21 and the concave cylindrical lens 22 are disposed between the light source lamp LP and the first lens array 3 in order from the lamp side. The convex cylindrical lens 21 is a toric lens having positive refractive power (ie, positive refractive power) in the x direction and no refractive power in the y direction. The concave cylindrical lens 22 is a toric lens having negative refractive power in the x direction and no refractive power in the y direction.

[0107] FIG. 9 shows an xz section in which light flux is ...

Embodiment 3

[0142]14 and 15 show the configuration of an optical system for image projection as Embodiment 3 of the present invention. This embodiment is a modified example, and the same elements as those described in Embodiment 2 are assigned the same reference numerals.

[0143] The present embodiment corresponds to an optical system in which an aperture stop is provided in the illumination optical system of Embodiment 2. The aperture stop is provided at a position close to the polarization conversion element 5 .

[0144] FIG. 14 shows an xz section in which light flux is compressed by the convex cylindrical lens 21 and the concave cylindrical lens 22 . FIG. 15 shows a yz section in which light flux is not refracted by the convex cylindrical lens 21 and the concave cylindrical lens 22 .

[0145] The white illuminating light flux emitted from the light emitting tube 1 is collimated by the reflector 2 to become a parallel light flux, and then enters the convex cylindrical lens 21 . The...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

An optical system for image projection is disclosed which is capable of improving contrast while suppressing reduction of light amount. The optical system includes a converging optical system, and a polarization beam splitting surface transmitting an incoming light flux having a first polarization direction from the converging optical system, to introduce it to the image-forming element and causing light having a second polarization direction, of an outgoing light flux from the image-forming element, to proceed to a projection optical system. In a first cross-section parallel to a normal to the polarization beam splitting surface, the converging optical system has a configuration causing an incident angle on the splitting surface of a light ray passing through a barycenter of intensity distribution of the outgoing light flux to be larger than an incident angle thereon of a light ray passing through a barycenter of intensity distribution of the incoming light flux.

Description

technical field [0001] The present invention relates to an optical system for an image projection device using a reflective image forming element. Background technique [0002] Japanese Patent Laid-Open No. 2000-206463 has disclosed an image projection device that uses a reflective image forming element such as a reflective liquid crystal panel, and in which an optical system such that the image forming element is illuminated The converging angles of the luminous flux are different from each other on two mutually perpendicular sections in order to improve the contrast of the projected image. [0003] This optical system makes the convergence angle of the luminous flux in a direction small. In this direction, the illumination light or projection light is bent by 90 degrees (that is, a certain direction) by the polarization beam splitting film of the polarization beam splitter. The polarization beam splitter uses for introducing illumination light into a reflective image form...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G02B27/28G02B27/18G03B21/00G02F1/13H04N5/74
Inventor 奥山敦山内悠须藤贵士门脇亮太
Owner CANON KK