Driving circuit, LED head and image forming apparatus

A driving circuit, comprising:

• a driving section configured to supply a drive electric current to record elements to construct an array, the drive electric current driving the record elements;
• and
• a reference electric current generating circuit configured to generate a reference electric current and a control voltage according to a reference voltage, so that the generated reference electric current and the generated control voltage respectively control the drive electric current and the drive section;
• and
• a control voltage output section configured to input a drive signal and output the generated control voltage according to the drive signal,
• wherein the drive section is composed of a plurality of series connection circuits that are connected in parallel, each series connection circuit being composed of a first drive transistor, a second drive transistor and a third drive transistor that are connected in series;
• the reference electric current generating circuit includes:
• a trapezoid wave circuit configured to input the drive signal, change the shape of the drive signal to a trapezoidal shape by adding transition time, and output the drive signal in the trapezoidal shape, and
• a feedback circuit configured to input the reference voltage and generate the reference electric current according to the reference voltage and the drive signal in the trapezoidal shape,
• wherein the first drive transistor of each series connection circuit is configured to receive at a control terminal thereof the control voltage outputted from control voltage output section, and operate according to the received control voltage,
• the second drive transistor of each series connection circuit is configured to receive at a control terminal thereof a drive electric current adjustment signal to adjust an electric current value of the drive electric current, and
• the third drive transistor of each series connection circuit is configured to receive at a control terminal thereof a drive electric current ON/OFF signal to control on/off of the drive electric current, and operate according to the received drive electric current ON/OFF signal.

A driving circuit, comprising:

• a driving section configured to supply a drive electric current to record elements to construct an array, the drive electric current driving the record elements;
• and
• a reference electric current generating circuit configured to generate a reference electric current and a control voltage according to a reference voltage, so that the generated reference electric current and the generated control voltage respectively control the drive electric current and the drive section;
• and,
• a control voltage output section configured to input a drive signal and output the generated control voltage according to the drive signal,
• wherein the drive section has a main driving section that is composed of a first drive transistor and a second drive transistor that are connected in series, and a subsidiary driving section that is composed of a plurality of series connection circuits that are connected in parallel, each series connection circuit being composed of a first drive transistor, a second drive transistor and a third drive transistor that are connected in series;
• the reference electric current generating circuit includes:
• a trapezoid wave circuit configured to input the drive signal, change the shape of the drive signal to a trapezoidal shape by adding transition time, and output the drive signal in the trapezoidal shape, and
• a feedback circuit configured to input the reference voltage and generate the reference electric current according to the reference voltage and the drive signal in the trapezoidal shape,
• wherein the first drive transistor of the main driving section and the first drive transistor of each series connection circuit of the subsidiary driving section are configured to receive at respective control terminals thereof the control voltage outputted from control voltage output section, and operate according to the received control voltage,
• the second drive transistor of each series connection circuit of the subsidiary driving section is configured to receive at a control terminal thereof a drive electric current adjustment signal to adjust an electric current value of the drive electric current, and
• the second transistor of the main driving section and the third drive transistor of each series connection circuit of the subsidiary driving section are configured to receive at respective control terminals thereof a drive electric current ON/OFF signal to control on/off of the drive electric current, and operate according to the received drive electric current ON/OFF signal.

A LED head, comprising a driving circuit, wherein the driving circuit includes:

• a drive transistor configured to supply a drive electric current to record elements to construct an array, the drive electric current driving the record elements;
• a reference electric current generating circuit configured to generate a reference electric current and a control voltage according to a reference voltage, so that the generated reference electric current and the generated control voltage respectively control the drive electric current and the drive transistor;
• and
• a control voltage output section configured to input a drive signal and output the generated control voltage according to the drive signal,
• wherein the drive transistor is composed of a first drive transistor and a second drive transistor that are connected in series;
• and
• the reference electric current generating circuit includes:
• a trapezoid wave circuit configured to input the drive signal, change the shape of the drive signal to a trapezoidal shape by adding transition time, and output the drive signal in the trapezoidal shape, and
• a feedback circuit configured to input the reference voltage and generate the reference electric current according to the reference voltage and the drive signal in the trapezoidal shape,
• wherein the first drive transistor is configured to receive at a control terminal thereof the control voltage outputted from control voltage output section, and operate according to the received control voltage;
• and
• the second drive transistor is configured to receive at a control terminal thereof a drive electric current ON/OFF signal to control on/off of the drive electric current, and operate according to the received drive electric current ON/OFF signal.

A LED head, comprising a driving circuit, wherein the driving circuit includes:

• a driving section configured to supply a drive electric current to record elements to construct an array, the drive electric current driving the record elements;
• and
• a reference electric current generating circuit configured to generate a reference electric current and a control voltage according to a reference voltage, so that the generated reference electric current and the generated control voltage respectively control the drive electric current and the drive section;
• and
• a control voltage output section configured to input a drive signal and output the generated control voltage according to the drive signal,
• wherein the drive section is composed of a plurality of series connection circuits that are connected in parallel, each series connection circuit being composed of a first drive transistor, a second drive transistor and a third drive transistor that are connected in series;
• the reference electric current generating circuit includes:
• a trapezoid wave circuit configured to input the drive signal, change the shape of the drive signal to a trapezoidal shape by adding transition time, and output the drive signal in the trapezoidal shape, and
• a feedback circuit configured to input the reference voltage and generate the reference electric current according to the reference voltage and the drive signal in the trapezoidal shape,
• wherein the first drive transistor of each series connection circuit is configured to receive at a control terminal thereof the control voltage outputted from control voltage output section, and operate according to the received control voltage,
• the second drive transistor of each series connection circuit is configured to receive at a control terminal thereof a drive electric current adjustment signal to adjust an electric current value of the drive electric current, and
• the third drive transistor of each series connection circuit is configured to receive at a control terminal thereof a drive electric current ON/OFF signal to control on/off of the drive electric current, and operate according to the received drive electric current ON/OFF signal.

A LED head, comprising a driving circuit, wherein the driving circuit includes:

• a driving section configured to supply a drive electric current to record elements to construct an array, the drive electric current driving the record elements;
• and
• a reference electric current generating circuit configured to generate a reference electric current and a control voltage according to a reference voltage, so that the generated reference electric current and the generated control voltage respectively control the drive electric current and the drive section;
• and
• a control voltage output section configured to input a drive signal and output the generated control voltage according to the drive signal,
• wherein the drive section has a main driving section that is composed of a first drive transistor and a second drive transistor that are connected in series, and a subsidiary driving section that is composed of a plurality of series connection circuits that are connected in parallel, each series connection circuit being composed of a first drive transistor, a second drive transistor and a third drive transistor that are connected in series;
• the reference electric current generating circuit includes:
• a trapezoid wave circuit configured to input the drive signal, change the shape of the drive signal to a trapezoidal shape by adding transition time, and output the drive signal in the trapezoidal shape, and
• a feedback circuit configured to input the reference voltage and generate the reference electric current according to the reference voltage and the drive signal in the trapezoidal shape,
• wherein the first drive transistor of the main driving section and the first drive transistor of each series connection circuit of the subsidiary driving section are configured to receive at respective control terminals thereof the control voltage outputted from control voltage output section, and operate according to the received control voltage,
• the second drive transistor of each series connection circuit of the subsidiary driving section is configured to receive at a control terminal thereof a drive electric current adjustment signal to adjust an electric current value of the drive electric current, and
• the second transistor of the main driving section and the third drive transistor of each series connection circuit of the subsidiary driving section are configured to receive at respective control terminals thereof a drive electric current ON/OFF signal to control on/off of the drive electric current, and operate according to the received drive electric current ON/OFF signal.

An image forming apparatus, comprising a LED head, wherein the LED head comprises a driving circuit, and the driving circuit includes:

• a drive transistor configured to supply a drive electric current to record elements to construct an array, the drive electric current driving the record elements;
• a reference electric current generating circuit configured to generate a reference electric current and a control voltage according to a reference voltage, so that the generated reference electric current and the generated control voltage respectively control the drive electric current and the drive transistor;
• and
• a control voltage output section configured to input a drive signal and output the generated control voltage according to the drive signal,
• wherein the drive transistor is composed of a first drive transistor and a second drive transistor that are connected in series;
• and
• the reference electric current generating circuit includes:
• a trapezoid wave circuit configured to input the drive signal, change the shape of the drive signal to a trapezoidal shape by adding transition time, and output the drive signal in the trapezoidal shape, and
• a feedback circuit configured to input the reference voltage and generate the reference electric current according to the reference voltage and the drive signal in the trapezoidal shape,
• wherein the first drive transistor is configured to receive at a control terminal thereof the control voltage outputted from control voltage output section, and operate according to the received control voltage;
• and
• the second drive transistor is configured to receive at a control terminal thereof a drive electric current ON/OFF signal to control on/off of the drive electric current, and operate according to the received drive electric current ON/OFF signal.

An image forming apparatus, comprising a LED head, wherein the LED head comprises a driving circuit, and the driving circuit includes:

• a driving section configured to supply a drive electric current to record elements to construct an array, the drive electric current driving the record elements;
• and
• a reference electric current generating circuit configured to generate a reference electric current and a control voltage according to a reference voltage, so that the generated reference electric current and the generated control voltage respectively control the drive electric current and the drive section;
• and
• a control voltage output section configured to input a drive signal and output the generated control voltage according to the drive signal,
• wherein the drive section is composed of a plurality of series connection circuits that are connected in parallel, each series connection circuit being composed of a first drive transistor, a second drive transistor and a third drive transistor that are connected in series;
• the reference electric current generating circuit includes:
• a trapezoid wave circuit configured to input the drive signal, change the shape of the drive signal to a trapezoidal shape by adding transition time, and output the drive signal in the trapezoidal shape, and
• a feedback circuit configured to input the reference voltage and generate the reference electric current according to the reference voltage and the drive signal in the trapezoidal shape,
• wherein the first drive transistor of each series connection circuit is configured to receive at a control terminal thereof the control voltage outputted from control voltage output section, and operate according to the received control voltage,
• the second drive transistor of each series connection circuit is configured to receive at a control terminal thereof a drive electric current adjustment signal to adjust an electric current value of the drive electric current, and
• the third drive transistor of each series connection circuit is configured to receive at a control terminal thereof a drive electric current ON/OFF signal to control on/off of the drive electric current, and operate according to the received drive electric current ON/OFF signal.

An image forming apparatus, comprising a LED head, wherein the LED head comprises a driving circuit, and the driving circuit includes:

• a driving section configured to supply a drive electric current to record elements to construct an array, the drive electric current driving the record elements;
• and
• a reference electric current generating circuit configured to generate a reference electric current and a control voltage according to a reference voltage, so that the generated reference electric current and the generated control voltage respectively control the drive electric current and the drive section;
• and
• a control voltage output section configured to input a drive signal and output the generated control voltage according to the drive signal,
• wherein the drive section has a main driving section that is composed of a first drive transistor and a second drive transistor that are connected in series, and a subsidiary driving section that is composed of a plurality of series connection circuits that are connected in parallel, each series connection circuit being composed of a first drive transistor, a second drive transistor and a third drive transistor that are connected in series;
• the reference electric current generating circuit includes:
• a trapezoid wave circuit configured to input the drive signal, change the shape of the drive signal to a trapezoidal shape by adding transition time, and output the drive signal in the trapezoidal shape, and
• a feedback circuit configured to input the reference voltage and generate the reference electric current according to the reference voltage and the drive signal in the trapezoidal shape,
• wherein the first drive transistor of the main driving section and the first drive transistor of each series connection circuit of the subsidiary driving section are configured to receive at respective control terminals thereof the control voltage outputted from control voltage output section, and operate according to the received control voltage,
• the second drive transistor of each series connection circuit of the subsidiary driving section is configured to receive at a control terminal thereof a drive electric current adjustment signal to adjust an electric current value of the drive electric current, and
• the second transistor of the main driving section and the third drive transistor of each series connection circuit of the subsidiary driving section are configured to receive at respective control terminals thereof a drive electric current ON/OFF signal to control on/off of the drive electric current, and operate according to the received drive electric current ON/OFF signal.