Photoreceptor
AssigneeSharp Kabushiki Kaisha
InventorsTakayuki Shimizu, Takeshi Murata
Life of this patent
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Abstract
A photoreceptor is provided with an erroneous operation detection circuit for monitoring an output signal supplied from a slew rate variable output stage. The erroneous operation detection circuit performs such controls that a slew rate of output is decreased within a range in which a transmission speed of the slew rate variable output stage is not decreased. With this arrangement, it is possible to inhibit adverse effect on the output signal due to a parasite current caused between an output terminal of the photoreceptor and photoelectric converting means, such as a photodiode.
Claims12
A photoreceptor comprising:
- photoelectric converting means for receiving an optical signal and converting the optical signal into an electric signal;
- output means for outputting a digital signal in accordance with the electric signal;
- and
- erroneous operation detection means for monitoring the digital signal thus outputted from the output means, so as to detect erroneous operation,
- the output means including output slew rate changing means for changing a slew rate of output of the output means, and
- the erroneous operation detection means performing, when the erroneous operation detection means detects the erroneous operation, such control that a transmission speed of the output slew rate changing means is decreased.
A photoreceptor, comprising:
- photoelectric converting means for receiving an optical signal and converting the optical signal into an electric signal;
- output means for outputting a digital signal in accordance with the electric signal;
- and
- power source voltage detection means for detecting a voltage value of a power source voltage supplied to the output means,
- the output means including output slew rate changing means for changing a slew rate of output of the output means, and
- the power source voltage detection means controlling the slew rate of the output of the output slew rate changing means in accordance with a change in the power source voltage.
A photoreceptor comprising:
- a photodiode for receiving an optical signal and converting the optical signal into an electric signal;
- an output circuit for outputting a digital signal in accordance with the electric signal;
- and
- an erroneous operation detection circuit for monitoring the digital signal outputted from the output means, and detecting erroneous operation,
- the output circuit including an output slew rate changing element for changing a slew rate of output of the output circuit, and
- the erroneous operation detection circuit performing, when the erroneous operation detection circuit detects the erroneous operation, such control that the slew rate of the output of the slew rate changing element is decreased.
Dependencies are inferred from the claim text.