Image-quality stabilizer for an electrophotographic apparatus
First Claim
1. An image-quality stabilizer for an electrophotographic apparatus comprising electrophotographic processing means, said electrophotographic processing means including a photoreceptor and transfer means, said image-quality stabilizer comprising:
- optical detecting means for optically detecting an amount of toner deposited on said photoreceptor;
process control means for controlling said electrophotographic processing means so that an amount of toner forming a reference toner image on said photoreceptor is equal to a predetermined reference value;
transfer control means for controlling said transfer means so as to transfer a reference toner image formed after controlling said electrophotographic processing means to a transfer sheet; and
reference-value adjusting means for adjusting the reference value based on a value detected by said optical detecting means after transferring the reference toner image to the transfer sheet.
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Accused Products
Abstract
An image-quality stabilizer for an electrophotographic apparatus forms a toner patch on a photoreceptor drum, detects the amount of toner attracted to the photoreceptor drum by an optical sensor, and controls each processing device so that the detected value is equal to a reference value which has been detected and stored when the number of image forming operations performed is low. After the control, the toner patch is transferred to a transfer sheet, and the amount of toner remaining on the photoreceptor drum is detected. The reference value is adjusted based on the detected value so as to compensate for a lowering of transfer efficiency. Or the lowering of transfer efficiency is compensated by controlling variables such as transfer output so that the detected value is equal to a reference residual value which has been detected and stored when the number of image forming operations performed is low. This arrangement restrains a lowering of image density due to a change in the transfer efficiency. It is therefore possible to control stabilizing the image quality accurately and to form images of stable quality.
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Citations
17 Claims
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1. An image-quality stabilizer for an electrophotographic apparatus comprising electrophotographic processing means, said electrophotographic processing means including a photoreceptor and transfer means, said image-quality stabilizer comprising:
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optical detecting means for optically detecting an amount of toner deposited on said photoreceptor; process control means for controlling said electrophotographic processing means so that an amount of toner forming a reference toner image on said photoreceptor is equal to a predetermined reference value; transfer control means for controlling said transfer means so as to transfer a reference toner image formed after controlling said electrophotographic processing means to a transfer sheet; and reference-value adjusting means for adjusting the reference value based on a value detected by said optical detecting means after transferring the reference toner image to the transfer sheet. - View Dependent Claims (2)
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3. An image-quality stabilizer for an electrophotographic apparatus comprising electrophotographic processing means, said electrophotographic processing means including a photoreceptor, transfer means and separating means, said image-quality stabilizer comprising;
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optical detecting means for optically detecting an amount of toner deposited on said photoreceptor; process control means for controlling said electrophotographic processing means so that an amount of toner forming a reference toner image on the photoreceptor is equal to a predetermined reference value; transfer control means for controlling said transfer means so as to transfer a reference toner image formed after controlling said electrophotographic processing means to a transfer sheet; and first control means for controlling an output of said transfer means so that a value detected by said optical detecting means after the transfer of the reference toner image is equal to a reference residual value, the reference residual value being obtained by said optical detecting means when the reference toner image for determining the reference value is transferred to the transfer sheet. - View Dependent Claims (4, 5, 6)
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7. An image-quality stabilizer for an electrophotographic apparatus comprising electrophotographic processing means, said electrophotographic processing means including a photoreceptor, transfer means and charger means, said image-quality stabilizer comprising;
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optical detecting means for optically detecting an amount of toner deposited on said photoreceptor; process control means for controlling said electrophotographic processing means so that an amount of toner forming a reference toner image on said photoreceptor is equal to a predetermined reference value; transfer control means for controlling said transfer means so as to transfer a reference toner image formed after controlling said electrophotographic processing means to a transfer sheet; and control means for controlling an output of said charger means so that a value detected by said optical detecting means after the transfer of the reference toner image is equal to a reference residual value, the reference residual value being obtained by said optical detecting means when the reference toner image for determining the reference value is transferred to the transfer sheet. - View Dependent Claims (8)
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9. An image-quality stabilizer for an electrophotographic apparatus comprising electrophotographic processing means, said electrophotographic processing means including a photoreceptor, transfer means and pre-transfer charger means used for removing charges on said photoreceptor immediately before a transfer operation, said image-quality stabilizer comprising:
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optical detecting means for optically detecting an amount of toner deposited on said photoreceptor; process control means for controlling said electrophotographic processing means so that an amount of toner forming a reference toner image on said photoreceptor is equal to a predetermined reference value; transfer control means for controlling said transfer means so as to transfer a reference toner image formed after controlling said electrophotographic processing means to a transfer sheet; and control means for controlling an output of said pre-transfer charger means so that a value detected by said optical detecting means after the transfer of the reference toner image is equal to a reference residual value, the reference residual value being measured by said optical detecting means when the reference toner image for determining the reference value is transferred to the transfer sheet. - View Dependent Claims (10)
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11. An image-quality stabilizer for an electrophotographic apparatus comprising electrophotographic processing means including a photoreceptor, transfer means and a light source used for removing charges on said photoreceptor immediately before a transfer operation, said image-quality stabilizer comprising:
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optical detecting means for optically detecting an amount of toner deposited on said photoreceptor; process control means for controlling said electrophotographic processing means so that an amount of toner forming a reference toner image on said photoreceptor is equal to a predetermined reference value; transfer control means for controlling said transfer means so as to transfer a reference toner image formed after controlling said electrophotographic processing means to a transfer sheet; and control means for controlling a quantity of light of said light source so that a value detected by said optical detecting means after the transfer of the reference toner image is equal to a reference residual value, the reference residual value being obtained by said optical detecting means when the reference toner image for determining the reference value is transferred to the transfer sheet. - View Dependent Claims (12)
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13. An image-quality stabilizer for an electrophotographic apparatus comprising electrophotographic processing means, said electrophotographic processing means including a photoreceptor, transfer means and development means, said image-quality stabilizer comprising:
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optical detecting means for optically detecting an amount of toner deposited on said photoreceptor; process control means for controlling said electrophotographic processing means so that an amount of toner forming a reference toner image on said photoreceptor is equal to a predetermined reference value; transfer control means for controlling said transfer means so as to transfer a reference toner image formed after controlling said electrophotographic processing means to a transfer sheet; and control means for controlling an amount of a developer to be supplied by said development means so that a value detected by said optical detecting means after the transfer of the reference toner image is equal to a reference residual value, the reference residual value being obtained by said optical detecting means when the reference toner image for determining the reference value is transferred to the transfer sheet. - View Dependent Claims (14, 15)
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16. An image-quality stabilizer for an electrophotographic apparatus comprising electrophotographic processing means, said electrophotographic processing means including a photoreceptor, transfer means and pre-cleaning charger means for removing charges on said photoreceptor before a cleaning operation, said image-quality stabilizer comprising:
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optical detecting means for optically detecting an amount of toner deposited on said photoreceptor; process control means for controlling said electrophotographic processing means so that an amount of toner forming a reference toner image on said photoreceptor is equal to a predetermined reference value; transfer control means for controlling said transfer means so as to transfer a reference toner image formed after controlling said electrophotographic processing means to a transfer sheet; and control means for calculating a transfer efficiency from values detected by said optical detecting means before and after transferring the reference toner image and for controlling an output of said pre-cleaning charger means in accordance with the transfer efficiency. - View Dependent Claims (17)
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Specification