Capacitive load driving circuit and image forming apparatus

Patent metadata

Field	Value
Publication number	US-10596807-B2
Application number	US-201816143722-A
Country	US
Kind code	B2
Filing date	Sep 27, 2018
Priority date	Mar 19, 2018
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A capacitive load driving circuit includes a first switching element, a second switching element, a third switching element, a fourth switching element and voltage dropper elements. The first switching element is provided on a first charging path extending from a power supply to a capacitive load. The second switching element is provided on a second charging path extending from a capacitor to the capacitive load. The third switching element is provided on a first discharging path extending from the capacitive load to a ground. The fourth switching element is provided on a second discharging path extending from the capacitive load to the capacitor. The voltage dropper elements are provided on each of control signal power supply paths to the first switching element, to the second switching element, to the third switching element and to the fourth switching element. The voltage dropper elements are configured to make electric current flow more easily through the second charging path than through the first charging path when charging the capacitive load and to make electric current flow more easily through the second discharging path than through the first discharging path when discharging the capacitive load by a potential difference.

First claim

What is claimed is:

1. A capacitive load driving circuit for charging and discharging a capacitive load repeatedly based on a control signal, the capacitive load driving circuit comprising:
a first switching element that is interposed on a first charging path through which electric current flows from a charging power supply to the capacitive load, the charging power supply being configured to charge the capacitive load;
a second switching element that is interposed on a second charging path through which electric current flows from a capacitor to the capacitive load, the electric current being rectified by a first back flow preventing diode;
a third switching element that is interposed on a first discharging path through which electric current flows from the capacitive load to a ground;
a fourth switching element that is interposed on a second discharging path through which electric current flows from the capacitive load to the capacitor, the electric current being rectified by a second back flow preventing diode;
a first voltage dropper element that is provided between the first switching element and the second switching element on a voltage input path to a control terminal configured to indicate an on-state based on an input signal; and
a second voltage dropper element that is provided between the third switching element and the fourth switching element on a voltage input path to a control terminal configured to indicate an on-state based on an input signal,
wherein a control terminal of the first switching element is connected to a low potential side of the first voltage dropper element,
a control terminal of the second switching element is connected to a high potential side of the first voltage dropper element,
a control terminal of the third switching element is connected to a low potential side of the second voltage dropper element, and
a control terminal of the fourth switching element is connected to a high potential side of the second voltage dropper element.

2. The capacitive load driving circuit according to claim 1 , further comprising:
a third voltage dropper element,
wherein the control terminal of the first switching element is connected to a high potential side of the third voltage dropper element, and
the control terminal of the third switching element is connected to a low potential side of the third voltage dropper element.

3. The capacitive load driving circuit according to claim 1 , comprising:
a differential amplifier that generates a control signal and applies the control signal to the capacitive load driving circuit, and
a signal line for negative feedback of a voltage driving the capacitive load to the differential amplifier.

4. The capacitive load driving circuit according to claim 2 , comprising:
a differential amplifier that generates a control signal and applies the control signal to the capacitive load driving circuit, and
a signal line for negative feedback of a voltage driving the capacitive load to the differential amplifier.

5. An image forming apparatus comprising:
an ejecting unit that ejects a droplet of liquid onto a recording medium by driving the capacitive load with the capacitive load driving circuit according to claim 1 .

6. An image forming apparatus comprising:
an ejecting unit that ejects a droplet of liquid onto a recording medium by driving the capacitive load with the capacitive load driving circuit according to claim 2 .

7. An image forming apparatus comprising:
an ejecting unit that ejects a droplet of liquid onto a recording medium by driving the capacitive load with the capacitive load driving circuit according to claim 3 .

8. An image forming apparatus comprising:
an ejecting unit that ejects a droplet of liquid onto a recording medium by driving the capacitive load with the capacitive load driving circuit according to claim 4 .

Assignees

• Fuji Xerox Co Ltd

Inventors

• Ikeda Chikaho

Classifications

• B41J2/04541 Primary

  Specific driving circuit · CPC title

• H03F2200/297

  the loading circuit of an amplifying stage comprising a capacitor · CPC title

• H03K17/6872

  using complementary field-effect transistors · CPC title

• B41J29/38

  Drives, motors, controls or automatic cut-off devices for the entire printing mechanism · CPC title

• B41J2/04581

  controlling heads based on piezoelectric elements · CPC title