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US 9,791,802 B2Granted
Scanning optical device and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorKenji Nemoto
Life of this patent
Estimating the term…
Abstract
At image formation time, when the light amount setting value used in the image formation is equal to or larger than the light amount value Xm affected by the stray light, a corrected signal width Tw corresponding to the light amount setting value used in the image formation is calculated from the increase ratio αn of the signal width tn of a detection signal acquired in a region having a light amount value smaller than the light amount value Xm affected by the stray light; and a synchronization signal is generated on the basis of a center position of the corrected signal width Tw.
Claims18
A scanning optical device comprising:
- a laser light source that emits a laser light beam;
- a laser control section that controls a light amount of the laser light beam emitted from the laser light source;
- a photodetector that converts the laser light beam into an electric signal;
- a signal-width detecting section that detects a signal width using an output waveform of the photodetector as a detection signal on the basis of a threshold;
- and
- a control section that cause the signal-width detecting section to detect a first signal width when the laser light source emit laser light beams at a first light amount and a second signal width when the laser light source emit laser light beams at a second light amount larger than the first light amount,
- wherein when a value related to a change of a difference between the first signal width and the second signal width is equal to or larger than a given value and the light amount used in image formation is equal to or larger than the second light amount, the control section acquires a corrected signal width corresponding to the light amount used in image formation based on a signal width detected when the laser light beam at a light amount smaller than the second light amount is emitted.
4 more elements
A scanning optical device comprising:
- a laser light source that emits a laser light beam;
- a laser control section that controls a light amount of the laser light beam emitted from the laser light source;
- a photodetector that converts the laser light beam into an electric signal;
- a signal-width detecting section that detects a signal width using an output waveform of the photodetector as a detection signal on the basis of a first threshold;
- and
- a control section that cause the signal-width detecting section to detect a first signal width when the laser light source emit laser light beams at a first light amount and a second signal width when the laser light source emit laser light beams at a second light amount larger than the first light amount,
- wherein when a value related to a change of a difference between the first signal width and the second signal width is equal to or larger than a given value and the light amount used in image formation is equal to or larger than the second light amount, the control section causes the signal-width detecting section to detect a detection width of the detection signal on the basis of a second threshold larger than the first threshold.
4 more elements
An image forming apparatus comprising:
- a scanning optical device including:
- a laser light source that emits a laser light beam;
- a laser control section that controls a light amount of the laser light beam emitted from the laser light source;
- a photodetector that converts the laser light beam into an electric signal;
- a signal-width detecting section that detects a signal width using an output waveform of the photodetector as a detection signal on the basis of a threshold;
- and
- a control section that cause the signal-width detecting section to detect a first signal width when the laser light source emit laser light beams at a first light amount and a second signal width when the laser light source emit laser light beams at a second light amount larger than the first light amount,
- wherein when a value related to a change of a difference between the first signal width and the second signal width is equal to or larger than a given value and the light amount used in image formation is equal to or larger than the second light amount, the control section acquires a corrected signal width corresponding to the light amount used in image formation based on a signal width detected when the laser light beam at a light amount smaller than the second light amount is emitted,
- the scanning optical device scanning an image bearing member surface with the laser light beam to form a latent image;
- wherein the image forming apparatus further comprises:
- a developing section that deposits toner on the image bearing member and develops the latent image as a toner image;
- a transfer section that transfers the developed toner image to a transfer material;
- and
- a fixing section that fixes the transferred toner image.
11 more elements
An image forming apparatus comprising:
- a scanning optical device including:
- a laser light source that emits a laser light beam;
- a laser control section that controls a light amount of the laser light beam emitted from the laser light source;
- a photodetector that converts the laser light beam into an electric signal;
- a signal-width detecting section that detects a signal width using an output waveform of the photodetector as a detection signal on the basis of a first threshold;
- and
- a control section that cause the signal-width detecting section to detect a first signal width when the laser light source emit laser light beams at first light amount and a second signal width when the laser light source emit laser light beams at a second light amount larger than the first light amount,
- wherein when a value related to a change of a difference between the first signal width and the second signal width is equal to or larger than a given value and the light amount used in image formation is equal to or larger than the second light amount the control section causes the signal-width detecting section to detect a detection width of the detection signal on the basis of a second threshold larger than the first threshold,
- the scanning optical device scanning an image bearing member surface with the laser light beam to form a latent image;
- wherein the image forming apparatus further comprises:
- a developing section that deposits toner on the image bearing member and develops the latent image as a toner image;
- a transfer section that transfers the developed toner image to a transfer material;
- and
- a fixing section that fixes the transferred toner image.
11 more elements
Dependencies are inferred from the claim text.