Exposure apparatus for electrophotographic reproduction machines

Claim 2

In an electrophotographic reproduction machine, having a programming mechanism for single or multiple copying operations, an apparatus for adjusting the exposure, said apparatus comprising a setting device for setting the exposure, a resetting device for returning the setting device to the setting for normal exposure after it has been set at any other setting, and electrical means for actuating said resetting device in response to the end of a copying operation to return said setting device to said setting for normal exposure, said resetting device including means biasing the setting device into the setting for normal exposure, mechanical means being provided for immobilizing said setting device in its other set positions, said actuating means being adapted to release said immobilizing means, said setting device being rotatable for setting the exposure and said immobilizing means including an element movable radially with reference to the axis of rotation of said setting device to hold the setting device against rotation.

Claim 3

Apparatus according to claim 1, wherein said setting device includes a notched rotary element, said movable element of the immobilizing means comprising a resilient wire adapted to engage and catch in said notched rotary element. 3 In an electrophotographic reproduction machine, having a programming mechanism for single or multiple copying operations, an apparatus for adjusting the exposure, said apparatus comprising a setting device for setting the exposure, a resetting device for returning the setting device to the setting for normal exposure after it has been set at any other setting, and electrical means for actuating said resetting device in response to the end of a copying operation to return said setting device to said setting for normal exposure, said programming mechanism for single or multiple copying operations having an output signal for indicating the end of a copying operation, a timing device responsive to said signal for retarding said actuating means and thereby providing a predetermined time interval between the end of a copying operation and the return of said setting device to said setting for normal exposure and in which time interval an original being copied can be changed without resetting the exposure and the programming mechanism can be reset, and means responsive to the resetting of said programming mechanism for resetting said timing device.

Claim 4

In an electrophotographic reproduction machine, the apparatus comprising means for programming said machine for single or selected multiple copying operations, means for adjusting the exposure of said machine, said adjusting means including a setting device for setting the exposure, a resetting device for returning the setting device to the setting for normal exposure after it has been set at any other setting, and electrical means carried by said apparatus fOr actuating said resetting device in response to the end of a copying operation to return said setting device to said setting for normal exposure.

Claim 5

In an electrophotographic reproduction machine, the apparatus comprising means for programming said machine for single or selected multiple copying operations, means for adjusting the exposure of said machine, said adjusting means including a setting device for setting the exposure, a resetting device for returning the setting device to the setting for normal exposure after it has been set at any other setting, and electrical means carried by said apparatus fOr actuating said resetting device in response to the end of a copying operation to return said setting device to said setting for normal exposure.

Claim 6

Apparatus according to claim 4, wherein said resetting device includes means biasing the setting device into the setting for normal exposure, mechanical means being provided for immobilizing said setting device in its other set positions, said actuating means being adapted to release said immobilizing means.

Claim 7

Apparatus according to claim 5, wherein said actuating means comprises an electromagnet device.

Claim 8

Apparatus according to claim 5, wherein said biasing means includes a spring.

Claim 9

Apparatus according to claim 5, wherein said biasing means comprises two opposed springs.

Claim 10

Apparatus according to claim 4 wherein said electrical means includes means for generating an electrical signal in response to the end of a single or selected multiple copying operation, and means coupled to said signal generating means to actuate said resetting device in response to said signal to return said setting device to said setting for normal exposure.

Claim 11

Apparatus according to claim 4 including a pair of shutter plates having a pair of edges defining a gap therebetween and mounted for movement in directions for increasing or decreasing the size of said gap, said adjusting means being connected to said shutter plates for moving said shutters to selectively increase or decrease the distance between said edges and thereby increase or decrease said gap respectively, said resetting device including means for biasing said shutters for movement within a range of positions and into a predetermined position within said range defining a selected gap size for normal exposure, means for immobilizing said shutters from movement when in positions other than said predetermined position, said actuating means being adapted to release said immobilizing means.

Claim 12

Apparatus according to claim 10 wherein said electrical means includes means for generating an electrical signal in response to the end of a single or selected multiple copying operation, means coupled to said signal generating means to actuate said resetting device in response to said signal to return said setting device to said setting for normal exposure, said electrical signal generating means including an electrical circuit having switch elements for energizing said circuit when said shutters lie in positions other than in sai predetermined position and at the end of a copying operation, said switch elements being operable to de-energize said circuit when either said shutters are moved to said predetermined position or said machine is programmed for single or multiple copying operations.