Drive circuit, light emitting diode head, and image forming apparatus

A drive circuit for adjusting a drive current of a driven element, comprising:

• a resistor having a first end portion and a second end portion, said second end portion being connected to ground;
• a calculation amplifier having a first input terminal for receiving a standard voltage, a second input terminal, and an output terminal;
• a first conductive type transistor having a first terminal, a second terminal, and a control terminal, said second terminal being connected to the ground, said control terminal being connected to the output terminal;
• and
• a current-mirror circuit, said current-mirror including at least two second conductive type transistors, one of said two second conductive type transistors being a control side transistor, the other of said two second conductive type transistors being a follower side transistor, said control side transistor having a first current output terminal connected to the first terminal, said follower side transistor having a second current output terminal connected to the first end portion and the second input terminal.

A drive circuit for driving a driven element, comprising:

• a drive element for driving the driven element;
• a correction data input section for adjusting a drive current of the driven element;
• a resistor having a first end portion and a second end portion, said second end portion being connected to ground;
• and
• a control voltage generation section for generating a direction value of the drive current of the driven element according to correction data input from the correction data input section,
• wherein said control voltage generation section includes,
• a calculation amplifier having a first input terminal for receiving a standard voltage, a second input terminal connected to the first end portion, and an output terminal;
• a transistor having a first terminal and a control terminal, said control terminal being connected to the output terminal;
• a first current-mirror circuit, said first current-mirror including at least two first conductive type transistors, one of said two first conductive type transistors being a first control side transistor, the other of said two first conductive type transistors being a first follower side transistor, said first control side transistor having a first current output terminal connected to the first terminal, said first follower side transistor having a second current output terminal;
• and
• a second current-mirror circuit, said second current-mirror including at least two second conductive type transistors, one of said two second conductive type transistors being a second control side transistor, the other of said two second conductive type transistors being a second follower side transistor, said second control side transistor having a third current output terminal connected to the second current output terminal, said second follower side transistor having a fourth current output terminal connected to the second input terminal.

A drive circuit for adjusting a drive current of a driven element;

• a resistor having a first end portion and a second end portion, said second end portion being connected to ground;
• and
• a calculation amplifier having a first input terminal for receiving a standard voltage, a second input terminal connected to the first end portion, and an output terminal;
• a transistor having a first terminal and a control terminal, said control terminal being connected to the output terminal;
• a first current-mirror circuit, said first current-mirror including at least two first conductive type transistors, one of said two first conductive type transistors being a first control side transistor, the other of said two first conductive type transistors being a first follower side transistor, said first control side transistor having a first current output terminal connected to the first terminal, said first follower side transistor having a second current output terminal;
• and
• a second current-mirror circuit, said second current-mirror including at least two second conductive type transistors, one of said two second conductive type transistors being a second control side transistor, the other of said two second conductive type transistors being a second follower side transistor, said second control side transistor having a third current output terminal connected to the second current output terminal, said second follower side transistor having a fourth current output terminal connected to the second input terminal.