Method of maintaining the correct conditions of an electrophotographically duplicated image

Claim 5

The method as set forth in claim 2, which comprises setting the developing bias voltage slightly higher than the potential of an latent image corresponding to the background of a copy, and setting the upper limit of the developing bias voltage so that the developing bias voltage may not excessively increase even when the quantity of light reflected from the maximum reflection-factor area of the copy is small.

Claim 10

A method according to claim 5 wherein the controlling step comprises: varying a developing bias voltage to maintain a constant contrast between a high and low charged regions formed on the photosensitive medium by the dark-tone and light-tone areas in the event that further changes to the charging step are ineffective to maintain said constant contrast.

Claim 11

A method according to claim 5 wherein the controlling step comprises: varying the amount of exposure to maintain a constant contrast between a high and low charge regions formed on the photosensitive medium by the dark-tone and light-tone areas in the event that further changes to said charging step are ineffective to maintain said constant contrast.

Claim 12

A method as claimed in claim 5, wherein the electrophotographic process is repeated such that the detection of the difference between the quantities of charge is made during a first electrophotographic process and a second process is started after the condition has been changed for the second process. .Iadd.

Claim 15

A method according to claim 9, wherein said correcting step further comprises: correcting an amount of flare produced by contamination of an optical system employed in forming the electrostatic image based on the detected potential corresponding to said striped area. .Iaddend. .Iadd.11. A method of maintaining correct the electrostatic latent image conditions of an electrophotographically duplicated image, comprising: providing a reference plate having a wide dark-tone area, a wide light-tone area, and a striped area, setting said reference plate on a copy supporter together with an original copy so as to permit a duplicating process to proceed, forming an electrostatic latent image of said reference plate on a photosensitive medium, detecting respective potentials of portions of said electrostatic image corresponding to respective areas of said reference plate, and correcting at least one duplicating process condition to a predetermined condition according to the detected potentials of said portions of said electrostatic latent image, thereby maintaining a correct electrostatic latent image of the copy so that a correct duplicated image may be produced, wherein said correcting step comprises correcting an amount of flare produced by contamination of an optical system employed in forming the electrostatic image based on the detected potential corresponding to said

Claim 16

striped area. .Iaddend. .Iadd.12. A method of maintaining correct the electrostatic latent image conditions of an electrophotographically duplicated image, comprising: providing a reference plate having two wide areas dark-tone, light-tone and a striped area, setting said reference plate on a copy supporter together with an original copy so as to permit a duplicating process to proceed, forming an electrostatic latent image of said reference plate on a photosensitive medium, detecting a potential of said electrostatic image corresponding to each area of said reference plate, and detecting optical system contamination according to the detected potential of said electrostatic latent image thereby maintaining a correct electrostatic latent image of the copy so that a correct duplicated image may be produced.

Claim 17

striped area. .Iaddend. .Iadd.12. A method of maintaining correct the electrostatic latent image conditions of an electrophotographically duplicated image, comprising: providing a reference plate having two wide areas dark-tone, light-tone and a striped area, setting said reference plate on a copy supporter together with an original copy so as to permit a duplicating process to proceed, forming an electrostatic latent image of said reference plate on a photosensitive medium, detecting a potential of said electrostatic image corresponding to each area of said reference plate, and detecting optical system contamination according to the detected potential of said electrostatic latent image thereby maintaining a correct electrostatic latent image of the copy so that a correct duplicated image may be produced.