Image reading apparatus, light intensity control circuit, and light intensity control method
AssigneeBrother Kogyo Kabushiki Kaisha
InventorsTakahiro Ikeno, Shingo Fujiwara, Tetsuya Kato, Hirofumi Oguri
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Abstract
An aspect of the invention provides an image reading apparatus including: first and second light emitters that emit lights; a light guide unit that guides the lights emitted from the first and second light emitters to irradiate a document with the light; a photoelectric conversion unit that converts reflected light from the document into an image signal; and a control unit that controls the first light emitter to emit light for a first time period in a unit time period and controls the second light emitter to emit light for a second time period misaligned from the first time period in the unit time period.
Claims18
An image reading apparatus comprising:
- first and second light emitters that emit lights;
- a light guide unit that guides the lights emitted from the first and second light emitters to irradiate a document with the light;
- a photoelectric conversion unit that converts reflected light from the document into an image signal;
- and
- a control unit that controls the first light emitter to emit light for a first time period in a unit time period and controls the second light emitter to emit light for a second time period misaligned from the first time period in the unit time period.
An image reading apparatus comprising:
- a first LED that emits a light with a first color;
- a second LED that emits a light with a second color;
- a third LED that emits a light with the first color;
- a fourth LED that emits a light with the second color;
- a light guide unit that guides the lights emitted from the first to fourth LEDs to irradiate a document with the light;
- a photoelectric conversion unit that converts reflected light from the document into an image signal;
- and
- a control unit that controls the first LED to emit light for a first time period in an first unit time period, controls the second LED to emit light for a second time period misaligned from the first time period in the first unit time period, controls the third LED to emit light for a third time period in a second unit time period successive to the first unit time period and controls the fourth LED to emit light for a fourth time period misaligned from the third time period in the second unit time.
A light intensity control circuit for an image reading apparatus, the image reading apparatus including first and second light emitters that emit lights, a light guide unit that guides the lights emitted from the first and second light emitters to irradiate a document with the light, and a photoelectric conversion unit that converts reflected light from the document into an image signal, the light intensity control circuit comprising:
- a control unit that controls the first light emitter to emit light for a first time period in a unit time period and controls the second light emitter to emit light for a second time period misaligned from the first time period in the unit time period.
A light intensity control circuit for an image reading apparatus, the image reading apparatus including a first LED that emits a light with a first color, a second LED that emits a light with a second color, a third LED that emits a light with the first color, a fourth LED that emits a light with the second color, a light guide unit that guides the lights emitted from the first to fourth LEDs to irradiate a document with the light, and a photoelectric conversion unit that converts reflected light from the document into an image signal, the light intensity control circuit comprising:
- a control unit that controls the first LED to emit light for a first time period in an first unit time period, controls the second LED to emit light for a second time period misaligned from the first time period in the first unit time period, controls the third LED to emit light for a third time period in a second unit time period successive to the first unit time period and controls the fourth LED to emit light for a fourth time period misaligned from the third time period in the second unit time.
A light intensity control method comprising:
- emitting a first light from a first light emitter for a first time period in a unit time period;
- emitting a second light from a second light emitter for a second time period misaligned from the first time period in the unit time period;
- guiding the emitted lights to irradiate a document;
- and
- converting reflected light of the emitted lights reflected from the document into an image signal.
A light intensity control method comprising:
- emitting a first light with a first color from a first LED for a first time period in a first unit time period;
- emitting a second light with a second color from a second LED for a second time period misaligned from the first time period in the first unit time period;
- emitting a third light with the first color from a third LED for a third time period in a second unit time period successive to the first unit time period;
- emitting a fourth light with the second color from a fourth LED for a fourth time period misaligned from the third time period in the second unit time period;
- guiding the emitted lights to irradiate a document;
- and
- converting reflected light of the emitted lights reflected from the document into an image signal.
Dependencies are inferred from the claim text.