Title:
PROJECTION TYPE DISPLAY DEVICE
Document Type and Number:
Japanese Patent JP3639842
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a projection type display device capable of switching and displaying a bright image and an image having high contrast ratio.
SOLUTION: This display device includes an illumination optical system condensing luminous flux radiated from a light source 1 on a light valve 5 through a polarizing beam splitter 4, and a projection lens system 10 enlarging and projecting the luminous flux whose intensity is modulated corresponding to image information which should be the object of display by the light valve 5. In such a case, the device is provided with an optical diaphragm 6 for switching the f-number of the optical system in an optical path from the light source 1 to the splitter 4. By switching the diaphragm 6, the image which is bright but has low contrast ratio and the image which is dark but has high contrast ratio are switched and displayed.
Inventors:
Ryusaku Takahashi
Application Number:
JP16535897A
Publication Date:
April 20, 2005
Filing Date:
June 08, 1997
Export Citation:
Assignee:
Victor Company of Japan, Ltd.
International Classes:
G02B27/28; G03B21/00; H04N5/74; (IPC1-7): G02B27/28; H04N5/74
Domestic Patent References:
| JP5015036U | ||||
| JP8254662A | ||||
| JP61122626A |
Attorney, Agent or Firm:
Takama Imama