Light emitting element array, drive circuit, optical print head, and image forming apparatus
AssigneeOki Data Corporation
InventorAkira Nagumo
Life of this patent
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Abstract
A light emitting element array includes a plurality of light emitting elements each having a first terminal, a second terminal, and a third terminal. The light emitting elements are arranged next to each other to form a group. The first terminal receives a drive signal, the second terminal is connected to ground, and the third terminal has a threshold voltage or a threshold current controllable from outside so that the light emitting elements are driven in a time division way.
Claims8
A drive circuit for driving a plurality of light emitting thyristors each including an anode for receiving a drive signal to drive the light emitting thyristor, a cathode connected to ground, and a gate for receiving a control signal to drive the light emitting thyristor in a time division way, comprising:
- a plurality of drive elements for supplying the drive signal to the anodes of the light emitting thyristors;
- a plurality of common base lines for flowing the control signal to control on/off of the light emitting thyristors;
- and
- a plurality of individual circuits connected to the common base lines for supplying the control signal to the gates of the light emitting thyristors, said individual circuits having a function of shifting a level of the control signal,
- wherein each of said individual circuits is formed of an n-type conductive switch element having a first switch terminal connected to one of the common base lines, a second switch terminal connected to the gate, and a third switch terminal connected to the second switch terminal for controlling a conductive state between the first switch terminal and the second switch terminal.
A drive circuit for driving a plurality of light emitting thyristors each including an anode for receiving a drive signal to drive the light emitting thyristor, a cathode connected to ground, and a gate for receiving a control signal to drive the light emitting thyristor in a time division way, comprising:
- a plurality of drive elements for supplying the drive signal to the anodes of the light emitting thyristors;
- a plurality of common base lines for flowing the control signal to control on/off of the light emitting thyristors;
- and
- a plurality of individual circuits connected to the common base lines for supplying the control signal to the gates of the light emitting thyristors, said individual circuits having a function of shifting a level of the control signal,
- wherein each of said individual circuits is formed of a p-type conductive switch element having a first switch terminal connected to the gate, a second switch terminal connected to one of the common base lines, and a third switch terminal connected to the second switch terminal for controlling a conductive state between the first switch terminal and the second switch terminal.
Dependencies are inferred from the claim text.