Image density control apparatus

Claim 2

An image forming apparatus comprising: processing means for forming an image of an original on a recording member; detection means for detecting an original image density; and control means for controlling an operation condition of said processing means in accordance with an output from said detecting means, so as to regulate a copy image density; the control by said control means being such that the relationship between the detected original image density and the copy image density provides a substantially constant copy image density in an intermediate original image density range and provides variation of the copy image density in accordance with the original image density above and below said intermediate original image density range.

Claim 3

An image forming apparatus comprising: processing means for forming an image of an original; detection means for detecting an original image density; and control means for controlling an operation condition of said processing means in accordance with an output of said detection means, wherein said control means includes a memory for storing a data table corresponding to a relation between data associated with the original image density and data associated with the operation condition of said processing means, and determines the operation condition of said processing means by looking up the data table in accordance with the output from said detection means.

Claim 4

An image forming apparatus comprising: processing means for forming an image of an original; detection means for detecting an original image density; and control means for controlling an operation condition of said processing means in accordance with an output of said detection means, wherein said control means includes a memory for storing a data table corresponding to a relation between data associated with the original image density and data associated with the operation condition of said processing means, and determines the operation condition of said processing means by looking up the data table in accordance with the output from said detection means.

Claim 5

An image forming apparatus comprising: image forming means for forming an image, wherein said image forming means includes exposure means for exposing a medium to the image and processing means for processing the exposed image, there being a delay between exposure of a portion of the image and processing of that portion of the image; detection means for detecting an image density of the image which is exposed and for outputting a signal representing image density; and control means for processing the density signal to provide a control signal and for controlling an operable condition of the processing means in accordance with the control signal after a lapse of time related to said delay between exposure and processing of respective portions of the image.

Claim 6

An image forming apparatus comprising: image forming means for forming an image, wherein said image forming means includes exposure means for exposing a medium to the image and processing means for processing the exposed image, there being a delay between exposure of a portion of the image and processing of that portion of the image; detection means for detecting an image density of the image which is exposed and for outputting a signal representing image density; and control means for processing the density signal to provide a control signal and for controlling an operable condition of the processing means in accordance with the control signal after a lapse of time related to said delay between exposure and processing of respective portions of the image.

Claim 7

An image forming apparatus comprising: processing means for forming an image of an original; detection means for detecting an image density for each area of the original to produce a detection signal; and control means for controlling an operation condition of said processing means in accordance with an output of said detection means, wherein said control means processes the detection signal from said detection means so as to produce a plurality of control signals, each of which corresponds to a said area of the original, and controls said operation condition of said processing means for each said area of the original in response to said plurality of control signals.

Claim 8

An image forming apparatus comprising: processing means for forming an image of an original; detection means for detecting an image density for each area of the original to produce a detection signal; and control means for controlling an operation condition of said processing means in accordance with an output of said detection means, wherein said control means processes the detection signal from said detection means so as to produce a plurality of control signals, each of which corresponds to a said area of the original, and controls said operation condition of said processing means for each said area of the original in response to said plurality of control signals.

Claim 9

An image forming apparatus comprising: processing means for forming an image of an original, said processing means being capable of forming the image in accordance with a variable magnification; detection means for detecting an image density of the original; sampling means for sampling an output of said detection means at a predetermined interval and at a plural number of times, in synchronism with a reference signal; and control means for controlling an operation condition of said processing means in accordance with plural image density data sampled by said sampling means and a slected magnification so as to regulate a copy image density.

Claim 10

An image forming apparatus comprising: processing means for forming an image of an original, said processing means being capable of forming the image in accordance with a variable magnification; detection means for detecting an image density of the original; sampling means for sampling an output of said detection means at a predetermined interval and at a plural number of times, in synchronism with a reference signal; and control means for controlling an operation condition of said processing means in accordance with plural image density data sampled by said sampling means and a slected magnification so as to regulate a copy image density.

Claim 11

An image forming apparatus according to any one of claims 1 to 5, wherein said detection means detects light from an original in accordance with the original density.

Claim 12

An image forming apparatus according to any one of claims 1 to 5, wherein said detection means detects a potential of a latent image formed by the exposure of an original.

Claim 13

An image forming apparatus according to any one of claims 1, 2, 4 and 5, wherein said condition of said processing means controlled by said control means is a quantity of exposure light applied by an original exposure means.

Claim 14

An image forming apparatus according to any one of claims 1 to 5 wherein said condition of said processing means controlled by said control means is a quantity of developer applied by a developing means.

Claim 15

An image forming apparatus according to claim 1, wherein said control means linearly controls the control output for a change of the detected density in an intermediate density region and substantially constantly controls or controls with a different characteristic than said linear characteristic the control output in high and low density regions.

Claim 16

An image forming apparatus according to claim 2, wherein said memory is a read-only memory.

Claim 17

An image forming apparatus according to claim 3, wherein said exposed image processing means is developing means.

Claim 18

An image forming apparatus according to claim 3, wherein said control means samples a plurality of detected signals in a predetermined period and averages the samples to produce the control signal.

Claim 19

An image forming apparatus according to claim 4, wherein said control means produces the control signal based on a data for a current detection area and a data for a previous detection area.

Claim 20

An image forming apparatus according to claim 13, wherein said control means divides the original into a plurality of areas and produces the control signal for each area, and said predetermined period corresponds to the image formation time for the area.

Claim 21

An image forming apparatus according to claim 3, wherein said control means produces the control signal by adding detected original densities of preceding and/or succeeding parts, related to a specific part of the original being presently detected by said detection means, to a detected original density of said specific part of the original.