Inkjet recording apparatus
AssigneeFuji Xerox Co., Ltd.
InventorSunao Ishizaki
Life of this patent
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Abstract
An ink non-ejection detecting circuit device for an inkjet recording apparatus is disclosed which comprises a bridge circuit including a piezoelectric head having a piezoelectric element, a first resistor connected in series to the piezoelectric head, a capacitor provided outside the piezoelectric head, and a second resistor connected in series to the capacitor. A differential voltage that appears between the piezoelectric head and the first resistor and between the capacitor and the second resistor is amplified, so that the acoustic-system admittance of the piezoelectric head can be detected with a high SN ratio.
Claims30
An ink non-ejection detecting circuit for an inkjet recording apparatus, comprising:
- a bridge circuit including a piezoelectric head having a piezoelectric element, a first resistor connected in series with the piezoelectric head, a capacitor provided outside the piezoelectric head, and a second resistor connected in series with the capacitor;
- and
- a differential amplifier circuit that amplifies a differential voltage appearing between the piezoelectric head and the first resistor and between the capacitor and the second resistor.
A method for checking an inkjet recording apparatus wherein ink is ejected by a piezoelectric head having a piezoelectric element, comprising:
- forming a bridge circuit including the piezoelectric head, a first resistor connected in series with the piezoelectric head, a capacitor provided outside the piezoelectric head, and a second resistor connected in series with the capacitor;
- and
- amplifying a differential voltage that appears between the piezoelectric head and the first resistor and between the capacitor and the second resistor.
An ink non-ejection detecting circuit for an inkjet recording apparatus, comprising:
- a bridge circuit including a piezoelectric head having a piezoelectric element, a first resistor connected in series with the piezoelectric head, a capacitor provided outside the piezoelectric head, and a second resistor connected in series with the capacitor;
- a differential amplifier circuit that amplifies a differential voltage appearing between the piezoelectric head and the first resistor and between the capacitor and the second resistor;
- and
- a positive feedback circuit that adjusts a phase of the differential voltage so as to make null a phase difference between a signal for driving the bridge circuit and the differential voltage amplified by the differential amplifier circuit, thereby generating a driving signal for the bridge circuit.
A method for checking an inkjet recording apparatus wherein ink is ejected from a piezoelectric head having a piezoelectric element, the method comprising:
- forming a bridge circuit including the piezoelectric head having the piezoelectric element, a first resistor connected in series with the piezoelectric head, a capacitor provided outside the piezoelectric head, and a second resistor connected in series with the capacitor;
- forming a differential amplifier circuit that amplifies a differential voltage appearing between the piezoelectric head and the first resistor and between the capacitor and the second resistor in the bridge circuit;
- forming a positive feedback circuit that adjusts a phase of the differential voltage so as to make null a phase difference between a signal for driving the bridge circuit and the differential voltage;
- and
- using a signal generated by the positive feedback circuit as a driving signal for the bridge circuit.
Dependencies are inferred from the claim text.