Recording Apparatus

Abstract

A recording apparatus includes a head that discharges ink and a head driving circuit that generates a switching signal. The recording apparatus further includes a switching signal generating unit that generates and outputs a switching signal, a first switch that is turned on or off based on the switching signal and a second switch that is turned on or off based on the switching signal. A first DC voltage is converted into a second DC voltage by switching one of the first switch and the second switch based on the switching signal, and the second DC voltage is supplied to the head driving circuit. The first switch and the second switch may be turned on or off based on the detected temperature of the head or ink in the head.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a color ink jet printer, which is a recording apparatus according to aspects of the invention;

FIG. 2 is a block diagram schematically illustrating the electric circuit structure of the color ink jet printer;

FIG. 3 is a flowchart illustrating a printing process; and

FIG. 4 is a graph illustrating a head voltage set according to the temperature of ink.

Claims

1. A recording apparatus comprising: a head that discharges ink;a head driving circuit that drives the head;a switching signal generating unit that generates and outputs a switching signal;a first switch that is turned on or off based on the switching signal;a second switch that is turned on or off based on the switching signal, wherein a first DC voltage is converted into a second DC voltage by switching one of the first switch and the second switch based on the switching signal, and the second DC voltage is supplied to the head driving circuit;a temperature detector that detects a temperature of the head or a temperature of the ink in the head; anda controller that controls the switching signal generating unit to generate the switching signal, wherein the controller controls the switching signal generating unit to output the switching signal to the first switch when the detected temperature is less than a first predetermined temperature and to output the switching signal to the second switch when the detected temperature is equal to or greater than the first predetermined temperature.

2. The recording apparatus according to claim 1, wherein the first switch and the switching signal generating unit are realized on a single integrated circuit chip, andthe second switch is attached external to the integrated circuit chip having the first switch thereon.

3. The recording apparatus according to claim 2, further comprising: a common current detector external to the integrated circuit chip that detects a current flowing through the first switch and the second switch, wherein when an overcurrent is detected the switching signal generating circuit generates the switching signal to turn OFF the first and second switches.

4. The recording apparatus according to claim 3, wherein the common current detector sends the overcurrent detection signal to the controller.

5. The recording apparatus according to claim 1, wherein the temperature detector detects the temperature of the head driving circuit.

6. The recording apparatus according to claim 1, wherein the temperature detector detects the temperature of ink in the head.

7. The recording apparatus according to claim 1, wherein at least one of the first switch and the second switch is a MOS.

8. The recording apparatus according to claim 1, wherein the controller controls the switching signal generating unit to output the switching signal, the switching signal causing the second DC voltage to be supplied to the head driving circuit to drive the head to discharge the ink at a slower rate when the detected temperature is equal to or greater than a second predetermined temperature that is greater than the first predetermined temperature.

9. A recording apparatus comprising: a head that discharges ink;a head driving circuit that drives the head;a switching signal generating unit that generates and outputs a switching signal;a first switch that is turned on or off based on the switching signal;a second switch that is turned on or off based on the switching signal, wherein a first DC voltage is converted into a second DC voltage by switching one of the first switch and the second switch based on the switching signal, and the second DC voltage is supplied to the head driving circuit;a temperature detector that detects a temperature of the ink;a voltage detector that detects the second DC voltage; anda controller that controls the switching signal generating unit to generate the switching signal, wherein the controller controls the switching signal generating unit to output the switching signal to the first switch when the detected ink temperature is greater than or equal to a predetermined temperature, and if the ink temperature is less than the predetermined temperature the controller controls the switching signal generating unit to output the switching signal to the second switch when the detected second DC voltage is less than a predetermined voltage and to output the switching signal to the first switch when the detected second DC voltage is equal to or greater than the predetermined voltage.

10. The recording apparatus according to claim 9, wherein the second switch and the switching signal generating unit are realized on a single integrated circuit chip, andthe first switch is attached external to the integrated circuit having the first switch thereon.

11. The recording apparatus according to claim 10, further comprising: a common current detector external to the integrated circuit chip that detects a current flowing through the first switch and the second switch, wherein when an overcurrent is detected the switching signal generating circuit generates the switching signal to turn OFF the first and second switches.

12. The recording apparatus according to claim 11, wherein the common current detector sends the overcurrent detection signal to the controller.

13. The recording apparatus according to claim 9, wherein at least one of the first switch and the second switch is a MOS.

14. A recording apparatus comprising: a head that discharges ink;a head driving circuit that drives the head;a switching signal generating unit that generates and outputs a switching signal;a first switch that is turned on or off based on the switching signal;a second switch that is turned on or off based on the switching signal, wherein a first DC voltage is converted into a second DC voltage by switching one of the first switch and the second switch based on the switching signal, and the second DC voltage is supplied to the head driving circuit;a voltage detector that detects the second DC voltage; anda controller that controls the switching signal generating unit to generate the switching signal to output the switching signal to the first switch when the detected second DC voltage is less than a predetermined voltage and to output the switching signal to the second switch when the detected second DC voltage is equal to or greater than the predetermined voltage.

15. The recording apparatus according to claim 14, wherein the first switch and the switching signal generating unit are realized on a single integrated circuit chip, andthe second switch is attached external to the integrated circuit chip having the first switch thereon.

16. The recording apparatus according to claim 15, further comprising: a common current detector external to the integrated circuit chip that detects a current flowing through the first switch and the second switch, wherein when an overcurrent is detected the switching signal generating circuit generates the switching signal to turn OFF the first and second switches.

17. The recording apparatus according to claim 16, wherein the common current detector sends the overcurrent detection signal to the controller.

18. The recording apparatus according to claim 14, wherein at least one the first switch and the second switch is a MOS.

19. A method for controlling discharge of ink from a head in a recording apparatus comprising the steps of: detecting temperature of the head or ink in the head;generating a first switching signal when the detected temperature is less than a first predetermined temperature;generating a second switching signal when the detected temperature is equal to or greater than the first predetermined temperature;converting a first DC voltage into a second DC voltage in response to the generation of one of the first switching signal and the second switching signal; andsupplying the second DC voltage to drive a head driving circuit which drives the head to discharge ink.

20. The method of claim 19, further comprising the step of supplying the second DC voltage to the head driving circuit to drive the head to discharge the ink at a slower rate when the detected temperature is equal to or greater than a second predetermined temperature that is greater than the first predetermined temperature.