Image forming apparatus capable of correcting position deviation of image
AssigneeCanon Kabushiki Kaisha
InventorAtsutomo Yoshizawa
Life of this patent
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Abstract
A sensor for measuring a temperature of a portion near an exposing unit to expose a photosensitive drum and a sensor for measuring a temperature in an apparatus other than the exposing unit are provided, thereby controlling a registration correction operation in accordance with a difference between outputs of those sensors. Thus, the registration correction operation can be always executed at the optimum timing and a good image can be continuously formed.
Claims36
An image forming apparatus comprising:
- (a) image forming means which has an image holding member and forms an image onto a recording medium;
- (b) exposing means for exposing said image holding member;
- (c) correcting means for correcting a position of the image which is formed onto said recording medium by said image forming means;
- (d) first detecting means for detecting a temperature of a portion near said exposing means;
- (e) second detecting means for detecting a temperature in said apparatus other than said exposing means;
- and
- (f) control means for controlling a correction operation of said correcting means in accordance with outputs of said first and second detecting means.
An image forming apparatus comprising:
- (a) image forming means which has a photosensitive drum and forms an image by transferring an image on said photosensitive drum onto a recording medium;
- (b) exposing means for irradiating a laser beam onto said photosensitive drum;
- (c) a first sensor for measuring a temperature of a portion near said exposing means;
- (d) a second sensor for measuring a temperature in said apparatus other than said exposing means;
- (e) correcting means for correcting a position of the image which is formed by said image forming means;
- and
- (f) a controller for deciding whether a correction operation by said correcting means is executed or not in accordance with outputs of said first and second sensors.
An image forming apparatus, comprising:
- (a) image forming means having a plurality of image forming units each of which forms a respective image onto a recording medium;
- (b) detecting means for detecting, in a detection operation, a positional deviation between the images formed by the plurality of image forming units onto the recording medium;
- and
- (c) correcting means for correcting, in a correction operation, the positional deviation detected by said detecting means,
- wherein said apparatus has a first mode in which said detection operation and said correction operation are automatically executed at a predetermined interval which sequentially changes and a second mode in which said detection operation and said correction operation are automatically executed at every predetermined time.
An image forming apparatus, comprising:
- (a) a plurality of image forming units each of which forms a respective image onto a recording medium;
- (b) positional deviation detecting means for detecting a positional deviation between the images formed by said plurality of image forming units;
- and
- (c) correcting means for correcting the positional deviation between the images formed by said plurality of image forming units according to the detected result of said positional deviation detecting means,
- wherein said apparatus has a registration correcting sequence in which said detecting means detects the positional deviation and said correcting means corrects the positional deviation between the images formed by said plurality of image forming units, and
- wherein said apparatus has a first mode for executing said registration correcting sequence at a predetermined interval which sequentially changes and a second mode for executing said registration correcting sequence at every predetermined time.
An image forming apparatus, comprising:
- (a) a plurality of image forming units each of which forms a respective image on a recording medium;
- and
- (b) positional deviation detecting means for detecting, in a detecting operation, a positional deviation between the images formed by the plurality of image forming units,
- wherein said apparatus has a first mode in which the detecting operation of said detecting means is automatically executed at a predetermined interval which sequentially changes and a second mode in which the detecting operation is automatically executed at every predetermined time.
A controller used with an image forming apparatus in which respective images are formed on a recording medium by exposing respective image holding members of each of a plurality of image forming units using an exposing unit and in which a difference between positions of the images respectively formed by said plurality of image forming units is detected, in a detection operation, to correct said difference in a correction operation, said controller controlling the detection operation and the correction operation based upon a temperature at a first position near said exposing unit and a temperature at a second position in said apparatus different from the first position.
An image forming apparatus, comprising:
- (a) a plurality of image forming units each of which forms a respective image onto a recording medium;
- (b) detecting means for detecting, in a detection operation, a positional deviation between the images formed by the plurality of image forming units onto the recording medium;
- and
- (c) control means for correcting, in a correction operation, the positional deviation according to the detected result of said detecting means, said control means controlling said detection operation of said detecting means and said correction operation so that both said detection operation and said correction operation are each automatically executed at a predetermined interval which gradually changes.
An image forming apparatus, comprising:
- (a) a plurality of image forming units each of which forms a respective image onto a recording medium;
- (b) detecting means for detecting, in a detection operation, a positional deviation between the image formed by the plurality of image forming units onto the recording medium;
- (c) correcting means for correcting, in a correction operation, the positional deviation according to the detected result of said detecting means,
- wherein said apparatus has a registration correcting sequence in which said detection means detects the positional deviation and said correction means corrects the positional deviation, and wherein said registration correction sequence is executed at an interval which gradually changes.
Dependencies are inferred from the claim text.