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Title:
AUTOMATIC PIXEL POSITION ADJUSTING DEVICE
Document Type and Number:
Japanese Patent JP3445759
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To provide an automatic pixel position adjusting device constituted so that the pixel position can be adjusted even during a normal picture display in which the pictures are displayed by being superposed by a plurality of projectors and the operation cost can be reduced.
SOLUTION: A pattern for detecting the pixel position is displayed, in an extremely narrow area required for detecting the pixel position, through projectors 101 and 102 by being added to an image signal at a certain frame and subtracted from the image signal at the next frame by signal synthesis devices 110 and 111. The display time of the pattern is set to be the period of the minimum number of frames in which image pickup can be executed by an image pickup device 104, that means, about 10 msec. The position of the pixel is detected by a pixel position detection device 150 on the basis of the image signal obtained by subtracting the image signal of the latter image pickup from the image signal of the former image pickup. Then, since the display time of the pattern is short and the display area thereof is extremely narrow, the pattern cannot be perceived by an observer 108 even in the midst of displaying the normal image. Besides, since the polarity of the pattern becomes reverse between the continuous frames, the pattern is not noticed by the observer 108 because of the after image characteristics of eye.


Inventors:
Takayuki Okimura
Kenji Nakazawa
Nazujo Uehira
Application Number:
JP22191499A
Publication Date:
September 08, 2003
Filing Date:
August 05, 1999
Export Citation:
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Assignee:
Nippon Telegraph and Telephone Corporation
International Classes:
H04N5/74; G03B21/00; (IPC1-7): G03B21/00; H04N5/74
Domestic Patent References:
JP8168039A
Attorney, Agent or Firm:
Fujiya Shiga (1 person outside)