Photocopying – Projection printing and copying cameras – With focusing or projection screen
Patent
1989-06-22
1990-01-16
Griffin, Donald A.
Photocopying
Projection printing and copying cameras
With focusing or projection screen
355 68, 353 27R, G03B 1328, G03B 2780, G03B 2308
Patent
active
048946818
ABSTRACT:
An image reader is disclosed which is provided with a screen for an image recorded on a microfilm to be projected thereon and a photoelectric transferring element for transforming the image into electric signals. In a light path originating in a light source and reaching the photoelectric transferring element, a beam attenuating filter for attenuating the luminous energy of the beam of light exposed on the photoelectric transferring element is disposed and used for decreasing the difference in the illuminance of the light source during the reader mode for causing the image to be projected on the screen and during the transforming mode for causing the image to be exposed on the photoelectric transferring element. The illuminance of the light source is controlled by the variation of the intermittent frequency of the voltage applied to the light source. While the operation is proceeding in the transferring mode, the illuminance of the light source is controlled with the aforementioned intermittent frequency falling within the range of sonic frequency so as to permit variation of the illuminance of the light source in a multiplicity of stages. While the operation is in this mode, the sound of the movable components of the device being operated for scanning cancels the noise generated within the range of sonic frequency.
REFERENCES:
patent: 4286864 (1981-09-01), Lysle et al.
patent: 4339182 (1982-07-01), Ueda et al.
patent: 4591264 (1986-05-01), Ueda et al.
Ito Masaaki
Kusano Hideaki
Watanabe Yutaka
Griffin Donald A.
Minolta Camera Kabushiki Kaisha
LandOfFree
Image reader does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Image reader, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image reader will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1337893