JPS5541456A - Copying method - Google Patents

Abstract

PURPOSE: To make possible accurate measurement of the moving distance of film by moving the film for the specified distance in the direction opposite from the first direction then moving the same in the first direction after the projected images have been read on the screen and before the film is moved in the first direction.

CONSTITUTION: When a carrier mounting table is in a stoppage state, the projected image a₁ of the entire part of one frame is projected to the specified area of a screen 2 and a read state is established. The shaded area 27' on the screen 2 optically corresponds to the exposure position of a photosensitive drum and only the lines of the area 27' are projected onto the photoreceptor. In the case of starting copying operation, the film is first moved in the d direction being the second direction opposite from the c direction being the first direction where the end edge a of the projected image a₁ is approached to the exposure position. This is intended to remove the backlash, etc. of the connecting mechanism of the carrier mounting table and motor. This moving distance is the distance until the carrier mounting table is moved at a constant speed. After this, the carrier mounting table is moved in the c direction. Because of this, the carrier moves at a constant speed and pulse intervals also become constant, thus measurement of movement distance of good accuracy may be performed.

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