Bias circuit, image formation device and image forming apparatus
AssigneeRicoh Company, Ltd.
InventorHiroshi Okamura
Life of this patent
Estimating the term…
Abstract
A bias circuit includes one or more first Zener diodes electrically coupled to a member provided in a replacement unit, the one or more first Zener diodes being coupled in series. When the replacement unit is removably attached to a main unit including a power supply that has one or more second Zener diodes coupled in series, the first Zener diodes are electrically coupled to the second Zener diodes in parallel to change a bias voltage to be applied to the member, the bias voltage being supplied by the power supply. A total absolute value of breakdown voltages across the first Zener diodes is lower than a total absolute value of breakdown voltages across the second Zener diodes.
Claims15
A bias circuit comprising:
- one or more first Zener diodes electrically coupled to a member provided in a replacement unit, the one or more first Zener diodes being coupled in series,
- wherein in response to removably connecting the replacement unit to a main unit including a power supply that has one or more second Zener diodes coupled in series, the first Zener diodes are electrically coupled to the second Zener diodes in parallel to change a bias voltage to be applied to the member, the bias voltage being supplied by the power supply, and
- wherein a total absolute value of breakdown voltages across the first Zener diodes is lower than a total absolute value of breakdown voltages across the second Zener diodes to:
- bring the second Zener diodes into a non-operation state;
- and
- bring the first Zener diodes into an operation state for supplying the bias voltage from the power supply to the member.
An image formation device comprising:
- a latent image bearer;
- a toner bearer configured to develop a latent image on the latent image bearer by using toner carried on a surface of the toner bearer;
- a control member configured to contact with the toner bearer to control an amount of toner on the surface of the toner bearer;
- a bias circuit including one or more first Zener diodes coupled in series, the one or more first Zener diodes being electrically coupled to the control member,
- wherein in response to removably connecting the image formation device to an image forming apparatus including a power supply that has one or more second Zener diodes coupled in series, the one or more first Zener diodes are electrically coupled to the one or more second Zener diodes in parallel to change a bias voltage to be applied to the control member, the bias voltage being supplied by the power supply, and
- wherein a total absolute value of breakdown voltages across the first Zener diodes is lower than a total absolute value of breakdown voltages across the second Zener diodes to:
- bring the second Zener diodes into a non-operation state;
- and
- bring the first Zener diodes into an operation state for supplying the bias voltage from the power supply to the control member.
Dependencies are inferred from the claim text.