Illumination control for photocopying machine

Claim 1

An apparatus for copying an original using a light imaging system comprising a light source included in the imaging system, a light responsive means subjected to illumination from the light source, a controlled conduction device for controlling the energization of the light source, said device having a control electrode, capacitive means coupled to the control electrode to control the conductivity of the device, a potential source, first circuit means coupling the potential source and the capacitive means for establishing a reference potential level on the capacitive means, a normally incomplete second circuit means including the light responsive means for coupling the potential source and the capacitive means to change the potential level on the capacitive means to a level different from said reference level, and a switching means included in the first and second circuit means for normally completing the first circuit means and operable when the light source is to be energized for interrupting the first circuit means, completing the second circuit means, and initiating the energization of the light source.

Claim 2

An apparatus for copying an original using a light imaging system comprising a light source included in the imaging system, a light responsive means subjected to illumination from the light source, a controlled conduction device for controlling the energization of the light source, said device having a control electrode, capacitive means coupled to the control electrode to control the conductivity of the device, a potential source, first circuit means coupling the potential source and the capacitive means for establishing a reference potential level on the capacitive means, a normally incomplete second circuit means including the light responsive means for coupling the potential source and the capacitive means to change the potential level on the capacitive means to a level different from said reference level, and a switching means included in the first and second circuit means for normally completing the first circuit means and operable when the light source is to be energized for interrupting the first circuit means, completing the second circuit means, and initiating the energization of the light source.

Claim 5

An apparatus for copying an original on copy material using an imaging system comprising a light source included in the imaging system, a light responsive means disposed to receive illumination from the light source, a potential source, a control relay having an operating winding, a first pair of normally closed contacts and a second pair of normally open contacts, a first circuit for coupling the light source to the potential source to illuminate the light source, said first circuit including said first pair of contacts, capacitive means, second and third circuit means coupled to the capacitive means for charging and discharging the capacitive means, respectively, said second circuit means coupling the capacitive means to the potential source, one of said second and third circuit means including the light responsive means, a controlled conduction device coupled to the capacitive means and the winding of the control relay for controlling the operation of the control relay in accordance with the charging and discharging of the capacitive means by the second and third circuit means, a fourth circuit means for connecting the winding to the potential source through the second pair of contacts, and a control means operable from a normal setting to an operated setting when a copy is to be made, the control means in its operated setting controlling the completion of one and the interruption of the other of the second and third circuit means and the completion of the first circuit means, the operation of the control relay under the control of the capacitive means operating the contacts to interrupt the first circuit means and to close the fourth circuit means when a given level of light is detected by the light responsive means.

Claim 6

An apparatus for copying an original on copy material using an imaging system comprising a light source included in the imaging system, a light responsive means disposed to receive illumination from the light source, a potential source, a control relay having an operating winding, a first pair of normally closed contacts and a second pair of normally open contacts, a first circuit for coupling the light source to the potential source to illuminate the light source, said first circuit including said first pair of contacts, capacitive means, second and third circuit means coupled to the capacitive means for charging and discharging the capacitive means, respectively, said second circuit means coupling the capacitive means to the potential source, one of said second and third circuit means including the light responsive means, a controlled conduction device coupled to the capacitive means and the winding of the control relay for controlling the operation of the control relay in accordance with the charging and discharging of the capacitive means by the second and third circuit means, a fourth circuit means for connecting the winding to the potential source through the second pair of contacts, and a control means operable from a normal setting to an operated setting when a copy is to be made, the control means in its operated setting controlling the completion of one and the interruption of the other of the second and third circuit means and the completion of the first circuit means, the operation of the control relay under the control of the capacitive means operating the contacts to interrupt the first circuit means and to close the fourth circuit means when a given level of light is detected by the light responsive means.

Claim 8

An apparatus for copying an original using a light imaging system comprising a light source included in the imaging system, a light responsive means subjected to illumination from the light source, a relay having a winding and contact means operable between noRmal and actuated states, first circuit means including the contact means in their normal state for energizing the light source, a controlled conduction device for controlling the energization of the relay winding, said device having a control electrode, capacitive means coupled to the control electrode to control the conductivity of the device, a potential source, second circuit means coupling the potential source and the capacitive means for establishing a reference potential level on the capacitive means, third circuit means including the light responsive means for coupling the potential source and the capacitive means to change the potential level on the capacitive means to a level different from said reference level, a switching means normally completing the second circuit means and operable when the light source is to be energized for interrupting the second circuit means, completing the third circuit means, and completing said first circuit means to energize the light source, and fourth circuit means including the contact means and completed by operation of the contact means to their actuated state for maintaining the energization of the relay winding independent of the controlled conduction device.

Claim 9

An apparatus for copying an original using a light imaging system comprising a light source included in the imaging system, a light responsive means subjected to illumination from the light source, a relay having a winding and contact means operable between noRmal and actuated states, first circuit means including the contact means in their normal state for energizing the light source, a controlled conduction device for controlling the energization of the relay winding, said device having a control electrode, capacitive means coupled to the control electrode to control the conductivity of the device, a potential source, second circuit means coupling the potential source and the capacitive means for establishing a reference potential level on the capacitive means, third circuit means including the light responsive means for coupling the potential source and the capacitive means to change the potential level on the capacitive means to a level different from said reference level, a switching means normally completing the second circuit means and operable when the light source is to be energized for interrupting the second circuit means, completing the third circuit means, and completing said first circuit means to energize the light source, and fourth circuit means including the contact means and completed by operation of the contact means to their actuated state for maintaining the energization of the relay winding independent of the controlled conduction device.