CA2264417C - Thermal printer - Google Patents
Thermal printer Download PDFInfo
- Publication number
- CA2264417C CA2264417C CA002264417A CA2264417A CA2264417C CA 2264417 C CA2264417 C CA 2264417C CA 002264417 A CA002264417 A CA 002264417A CA 2264417 A CA2264417 A CA 2264417A CA 2264417 C CA2264417 C CA 2264417C
- Authority
- CA
- Canada
- Prior art keywords
- failure detection
- heater element
- power source
- thermal head
- source circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000001514 detection method Methods 0.000 claims abstract description 39
- 239000003990 capacitor Substances 0.000 claims abstract description 22
- 230000005669 field effect Effects 0.000 claims abstract description 9
- 238000007599 discharging Methods 0.000 claims abstract description 5
- 238000009499 grossing Methods 0.000 claims abstract description 5
- 101150022075 ADR1 gene Proteins 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000003111 delayed effect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000007792 addition Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
- B41J2/315—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material
- B41J2/32—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads
- B41J2/35—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by selective application of heat to a heat sensitive printing or impression-transfer material using thermal heads providing current or voltage to the thermal head
- B41J2/355—Control circuits for heating-element selection
Landscapes
- Accessory Devices And Overall Control Thereof (AREA)
- Electronic Switches (AREA)
Abstract
A thermal printer has a thermal head in which a Field Effect Transistor (FET) is connected in series to an individual heater element of each of a plurality of heater element groups which are connected in parallel with each other, and to which one capacitor for smoothing power and eliminating noise is connected in parallel relative to the heater element group.
The thermal head performs printing on thermal paper. The thermal printer includes a printing power source circuit, a failure detection power source circuit, a failure detection circuit for detecting the presence and absence of a failure of the heater element by comparing a voltage generated at opposite ends of the detecting resistor with a threshold value. Field Effect Transistor control means is provided for causing discharging of the capacitor by simultaneously turning on all of the Field Effect Transistors under the condition where the printing power source circuit and the failure detection power supply circuit are turned off, before the voltage is supplied from the failure detection power source circuit to the thermal head and the failure detection is performed.
The thermal head performs printing on thermal paper. The thermal printer includes a printing power source circuit, a failure detection power source circuit, a failure detection circuit for detecting the presence and absence of a failure of the heater element by comparing a voltage generated at opposite ends of the detecting resistor with a threshold value. Field Effect Transistor control means is provided for causing discharging of the capacitor by simultaneously turning on all of the Field Effect Transistors under the condition where the printing power source circuit and the failure detection power supply circuit are turned off, before the voltage is supplied from the failure detection power source circuit to the thermal head and the failure detection is performed.
Description
THERMAL PRINTER
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a thermal printer.
Description of the Related Art Among thermal heads employed in a heat transfer printer/a thermal printer, there is the thermal head to which a capacitor for smoothing power and eliminating noise is connected. Upon performing a failure detection of a heater element, it becomes possible to accurately detect a failure by discharging the capacitor.
Typically, in order to cause discharging of the capacitor, a dedicated discharge circuit is provided to discharge the capacitor as disclosed in the Japanese 'Unexamined Utility Model Publication No. Heisei 1-138744.
Accordingly, it results in complicated circuitry and control. Furthermore, upon detecting the failure, it can unwantedly cause color development on printing paper in case that the printing paper is held in contact with the thermal head .
S'f~tARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a thermal printer which can immediately discharge a _2_ capacitor without employing the dedicated capacitor discharge circuit and developing the color on the printing paper, and accurately detect the abnormality and the failure of a heater element group.
According to one aspect of the present invention, a thermal printer including a thermal head in which a plurality of FETs is connected in series to individual heater elements of each of a plurality of heater element groups which are connected in parallel with each other, and to which one capacitor for smoothing power and eliminating noise is connected in parallel relative to the heater element group, the thermal head performing printing on thermal paper, comprising:
a printing power source circuit for supplying a first given voltage of an electric power to the thermal head for performing printing;
a failure detection power source circuit for supplying a second given voltage of an electric power to the thermal head, wherein the second given voltage is lower than the first given voltage via a detecting resistor upon detecting a failure;
a failure detection circuit for detecting a presence or absence of a failure of the heater element by comparing a voltage generated at opposite ends of a detecting resistor with a threshold value; and Field Effect Transistor control means for causing discharge of the capacitor by simultaneously turning on all of the Field Effect Transistors under the condition where the printing power source circuit and the failure detection power supply circuit are turned off, before the second voltage is supplied from the failure detection power source circuit to the thermal head and the failure detection is performed.
BRIEF DESCRIPTION OF T8E DR~1.~TINGS
The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.
In the drawings:
Fig. 1 is an electric circuit diagram of the preferred embodiment of a thermal printer according to the present invention; and Figs . 2 (a) to 2 (g) are timing charts of an operation of the preferred embodiment of the thermal printer shown in Fig.
1.
DESCRIPTION OF TBE PREFERRED E1~ODIMENT
The present invention will be discussed hereinafter in detail in terms of the preferred embodiment of the present invention with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present _4_ invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures are not shown in detail in order to avoid unnecessarily obscuring the present invention.
Fig. 1 is a circuit diagram showing the structure of the preferred embodiment of a thermal printer according to the present invention.
The shown embodiment of the thermal printer has a thermal head 8a, a printing power source circuit 3 for supplying electric power to a thermal head 8a upon performing printing operation, a failure detection power source circuit 4 for supplying electric power to the thermal head 8a upon performing the failure detection, and a failure detection circuit 1.
In the thermal head 8a, FETs (Field Effect Transistors) 81_1 to 81_n are connected in series with respective of individual heater elements of heater element groups 86_1 to 86_"
which are connected in parallel with each other. These FETs 81_1 to 81_n are adapted to be selectively turned on and off by a driver 82 as FET control means. Furthermore, one capacitor 83 is connected in parallel relative to the circuit constructed by the heater element group 86_l to 86_" and the FET group 81_l to 81_n, serving to smooth power and eliminate noise.
The failure detection circuit 1 has a detecting resistor 12 connected between the failure detection power source circuit -S-4 and the thermal head 8a, an operational amplifier 19 for amplifying a voltage, VRa, generated at opposite ends of the detecting resistor 12, an Analog/Digital (A/D) converter 10 for converting output of the operational amplifier 19 to a digital value, and a processing unit 11 such as a CPU for making judgment of the presence or absence of the failure for each heater element 86_1 to 86_" by storing a register 111 with the digital value ADR1 to ADR" for each heater element 86_1 to 86_"
output from the A/D converter 10 and comparing with the threshold value.
Next, an operation will be discussed with reference to a timing chart in Figs. 2(a) to 2(g) in conjunction with Fig. 1.
In case that a detection of a failure of the heater element group 86_1 to 86_" is performed immediately after the printing operation is performed, an electric charge is accumulated in the capacitor 83, because a voltage, Vb, for developing the color is supplied from the printing power source circuit 3.
Accordingly, the electric charge accumulated in the capacitor 38 is discharged by simultaneously turning on all of the FETs 81_1 to 81_~ by the driver 82 of the thermal head 8a, and simultaneously applying a printing signal to all of the heater element groups 86_1 to 86_" (applying a dummy signal) , under the condition where the failure detection circuit 1 and the printing power source circuit 3 (Fig. 2(a)) are tuned off before the failure detection is performed, and the failure detection power source circuit 4 is also placed into off-state (placing a transistor 41 into off-stets).
By this, it becomes possible to discharge the electric charge accumulated in the capacitor 83 without providing the discharge circuit for discharging the electric charge of the capacitor 83 such as, a circuit of the combination of the discharge resistance and a switch. Therefore, it becomes possible to significantly shorten the discharge duration.
Next, assuming that a period longer than or equal to to after inputting of a failure detection trigger signal, Sst, to the failure detection power source circuit ~ is waited as a period required for stabilizing a detection voltage, Va, and thereafter, detection of the presence or absence of failure of the first heating element 86_1 is performed. For example, the printing signal Spt (Fig. 2(c)) to be supplied only the heater element 86_1 is input to the thermal head 8a. When the printing signal Spt is input, the driver 82 turns on only the first FET
81_1. At this time, the detection voltage, Va, which a.s lower than the voltage, Vb, output from the printing power source circuit 3 is output from the failure detection power source circuit 4, so that the current flows into the detecting resistor 12 to generate the oltage, YRa, at opposite ends of the detecting resistor 12.
At this time, it makes a difference in the voltage, VRa, _7.
due to whether the heater element 86_1 is normal or not (the voltage VRa becom~s lower according to the progress of fatigue of the heater element). However, it makes only a little difference, because the detection voltage, Va, is set as a low voltage in order to avoid developing the color of the printing paper. Accordingly, the voltage, VRa, is amplified by the operational amplifier 19.
A voltage, SRa, (Fig. 2(d)), amplified by the operational amplifier 19, is supplied to the A/D converter 10. Therefore, an analog signal is converted into digital data ADR1. The digital value thus converted is compared with the threshold value previously set in the processing unit 11. When the digital value is less than or equal to the threshold value, the heater element 86_1 is judged to be out of order.
In the operational amplifier 19, the voltage, VRa, at opposite ends of the detecting resistor 12 is amplified, and the voltage, SRa, is supplied to the A/D converter 10.
However, it takes time to set-up the voltage due to the integral by the capacitor 83 of the thermal head 8a (Fig.
BACKGROUND OF THE INVENTION
Field of the Invention The present invention relates to a thermal printer.
Description of the Related Art Among thermal heads employed in a heat transfer printer/a thermal printer, there is the thermal head to which a capacitor for smoothing power and eliminating noise is connected. Upon performing a failure detection of a heater element, it becomes possible to accurately detect a failure by discharging the capacitor.
Typically, in order to cause discharging of the capacitor, a dedicated discharge circuit is provided to discharge the capacitor as disclosed in the Japanese 'Unexamined Utility Model Publication No. Heisei 1-138744.
Accordingly, it results in complicated circuitry and control. Furthermore, upon detecting the failure, it can unwantedly cause color development on printing paper in case that the printing paper is held in contact with the thermal head .
S'f~tARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a thermal printer which can immediately discharge a _2_ capacitor without employing the dedicated capacitor discharge circuit and developing the color on the printing paper, and accurately detect the abnormality and the failure of a heater element group.
According to one aspect of the present invention, a thermal printer including a thermal head in which a plurality of FETs is connected in series to individual heater elements of each of a plurality of heater element groups which are connected in parallel with each other, and to which one capacitor for smoothing power and eliminating noise is connected in parallel relative to the heater element group, the thermal head performing printing on thermal paper, comprising:
a printing power source circuit for supplying a first given voltage of an electric power to the thermal head for performing printing;
a failure detection power source circuit for supplying a second given voltage of an electric power to the thermal head, wherein the second given voltage is lower than the first given voltage via a detecting resistor upon detecting a failure;
a failure detection circuit for detecting a presence or absence of a failure of the heater element by comparing a voltage generated at opposite ends of a detecting resistor with a threshold value; and Field Effect Transistor control means for causing discharge of the capacitor by simultaneously turning on all of the Field Effect Transistors under the condition where the printing power source circuit and the failure detection power supply circuit are turned off, before the second voltage is supplied from the failure detection power source circuit to the thermal head and the failure detection is performed.
BRIEF DESCRIPTION OF T8E DR~1.~TINGS
The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the present invention, which, however, should not be taken to be limitative to the invention, but are for explanation and understanding only.
In the drawings:
Fig. 1 is an electric circuit diagram of the preferred embodiment of a thermal printer according to the present invention; and Figs . 2 (a) to 2 (g) are timing charts of an operation of the preferred embodiment of the thermal printer shown in Fig.
1.
DESCRIPTION OF TBE PREFERRED E1~ODIMENT
The present invention will be discussed hereinafter in detail in terms of the preferred embodiment of the present invention with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present _4_ invention. It will be obvious, however, to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures are not shown in detail in order to avoid unnecessarily obscuring the present invention.
Fig. 1 is a circuit diagram showing the structure of the preferred embodiment of a thermal printer according to the present invention.
The shown embodiment of the thermal printer has a thermal head 8a, a printing power source circuit 3 for supplying electric power to a thermal head 8a upon performing printing operation, a failure detection power source circuit 4 for supplying electric power to the thermal head 8a upon performing the failure detection, and a failure detection circuit 1.
In the thermal head 8a, FETs (Field Effect Transistors) 81_1 to 81_n are connected in series with respective of individual heater elements of heater element groups 86_1 to 86_"
which are connected in parallel with each other. These FETs 81_1 to 81_n are adapted to be selectively turned on and off by a driver 82 as FET control means. Furthermore, one capacitor 83 is connected in parallel relative to the circuit constructed by the heater element group 86_l to 86_" and the FET group 81_l to 81_n, serving to smooth power and eliminate noise.
The failure detection circuit 1 has a detecting resistor 12 connected between the failure detection power source circuit -S-4 and the thermal head 8a, an operational amplifier 19 for amplifying a voltage, VRa, generated at opposite ends of the detecting resistor 12, an Analog/Digital (A/D) converter 10 for converting output of the operational amplifier 19 to a digital value, and a processing unit 11 such as a CPU for making judgment of the presence or absence of the failure for each heater element 86_1 to 86_" by storing a register 111 with the digital value ADR1 to ADR" for each heater element 86_1 to 86_"
output from the A/D converter 10 and comparing with the threshold value.
Next, an operation will be discussed with reference to a timing chart in Figs. 2(a) to 2(g) in conjunction with Fig. 1.
In case that a detection of a failure of the heater element group 86_1 to 86_" is performed immediately after the printing operation is performed, an electric charge is accumulated in the capacitor 83, because a voltage, Vb, for developing the color is supplied from the printing power source circuit 3.
Accordingly, the electric charge accumulated in the capacitor 38 is discharged by simultaneously turning on all of the FETs 81_1 to 81_~ by the driver 82 of the thermal head 8a, and simultaneously applying a printing signal to all of the heater element groups 86_1 to 86_" (applying a dummy signal) , under the condition where the failure detection circuit 1 and the printing power source circuit 3 (Fig. 2(a)) are tuned off before the failure detection is performed, and the failure detection power source circuit 4 is also placed into off-state (placing a transistor 41 into off-stets).
By this, it becomes possible to discharge the electric charge accumulated in the capacitor 83 without providing the discharge circuit for discharging the electric charge of the capacitor 83 such as, a circuit of the combination of the discharge resistance and a switch. Therefore, it becomes possible to significantly shorten the discharge duration.
Next, assuming that a period longer than or equal to to after inputting of a failure detection trigger signal, Sst, to the failure detection power source circuit ~ is waited as a period required for stabilizing a detection voltage, Va, and thereafter, detection of the presence or absence of failure of the first heating element 86_1 is performed. For example, the printing signal Spt (Fig. 2(c)) to be supplied only the heater element 86_1 is input to the thermal head 8a. When the printing signal Spt is input, the driver 82 turns on only the first FET
81_1. At this time, the detection voltage, Va, which a.s lower than the voltage, Vb, output from the printing power source circuit 3 is output from the failure detection power source circuit 4, so that the current flows into the detecting resistor 12 to generate the oltage, YRa, at opposite ends of the detecting resistor 12.
At this time, it makes a difference in the voltage, VRa, _7.
due to whether the heater element 86_1 is normal or not (the voltage VRa becom~s lower according to the progress of fatigue of the heater element). However, it makes only a little difference, because the detection voltage, Va, is set as a low voltage in order to avoid developing the color of the printing paper. Accordingly, the voltage, VRa, is amplified by the operational amplifier 19.
A voltage, SRa, (Fig. 2(d)), amplified by the operational amplifier 19, is supplied to the A/D converter 10. Therefore, an analog signal is converted into digital data ADR1. The digital value thus converted is compared with the threshold value previously set in the processing unit 11. When the digital value is less than or equal to the threshold value, the heater element 86_1 is judged to be out of order.
In the operational amplifier 19, the voltage, VRa, at opposite ends of the detecting resistor 12 is amplified, and the voltage, SRa, is supplied to the A/D converter 10.
However, it takes time to set-up the voltage due to the integral by the capacitor 83 of the thermal head 8a (Fig.
2 (d) ) .
Therefore, in the preferred embodiment of the present invention, the timing far starting the digital conversion is delayed by the A/D converter 10 (t5). It should be noted that only the timing for starting the digital conversion by the heater element fox starting the failure detection (for example, _g_ 86_1 )is delayed, when the failure detection of the heater element is continuously performed. Because, the detection voltage, Va, is already stable from the second time (for example, the second heater element 86_2) onward.
After the detection of the presence or absence of abnormality is finished with respect to the first heater element 86_1, the printing signal, Spt, supplied to only the second heater element 86_2 is supplied to the thermal head 8a, and the failure detection is similarly performed. Furthermore, such a process a.s repeatedly performed up to the final heater element 86_".
Therefore, since it is unnecessary to discharge the electric charge accumulated in the capacitor 83 for the heater element, it becomes possible to shorten the time for detecting the failure in comparison with the discharge for the heater element by the dedicated discharge circuit.
In the construction as set forth above, the electric charge accumulated in the capacitor for smoothing power and eliminating noise, which has an effect upon performing the failure detection of the heater element, can be discharged by simultaneously turning on all of the FETs (the dummy apply) without providing the special discharge circuit (for example, the circuit of the combination of the discharge resistance and the switch) to immediately discharge the capacitor. Therefore, it becom~s possible to shorten the discharge duration to a ~9-large extent in comparison with the prior art without developing the color of the printing paper.
E~rthermore, when failure detection is performed, it is possible to avoid developing the color of the printing paper upon detecting the failure by switching to a low voltage. It is also possible to shorten the time for detesting the failure in comparison with the prior art, since it is unnecessary to discharge the capacitor for the heater element.
Although the present invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodied within a scope encompassed and equivalents thereof with respect to the feature set out in the appended claim.
Therefore, in the preferred embodiment of the present invention, the timing far starting the digital conversion is delayed by the A/D converter 10 (t5). It should be noted that only the timing for starting the digital conversion by the heater element fox starting the failure detection (for example, _g_ 86_1 )is delayed, when the failure detection of the heater element is continuously performed. Because, the detection voltage, Va, is already stable from the second time (for example, the second heater element 86_2) onward.
After the detection of the presence or absence of abnormality is finished with respect to the first heater element 86_1, the printing signal, Spt, supplied to only the second heater element 86_2 is supplied to the thermal head 8a, and the failure detection is similarly performed. Furthermore, such a process a.s repeatedly performed up to the final heater element 86_".
Therefore, since it is unnecessary to discharge the electric charge accumulated in the capacitor 83 for the heater element, it becomes possible to shorten the time for detecting the failure in comparison with the discharge for the heater element by the dedicated discharge circuit.
In the construction as set forth above, the electric charge accumulated in the capacitor for smoothing power and eliminating noise, which has an effect upon performing the failure detection of the heater element, can be discharged by simultaneously turning on all of the FETs (the dummy apply) without providing the special discharge circuit (for example, the circuit of the combination of the discharge resistance and the switch) to immediately discharge the capacitor. Therefore, it becom~s possible to shorten the discharge duration to a ~9-large extent in comparison with the prior art without developing the color of the printing paper.
E~rthermore, when failure detection is performed, it is possible to avoid developing the color of the printing paper upon detecting the failure by switching to a low voltage. It is also possible to shorten the time for detesting the failure in comparison with the prior art, since it is unnecessary to discharge the capacitor for the heater element.
Although the present invention has been illustrated and described with respect to exemplary embodiment thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made therein and thereto, without departing from the spirit and scope of the present invention. Therefore, the present invention should not be understood as limited to the specific embodiment set out above but to include all possible embodiments which can be embodied within a scope encompassed and equivalents thereof with respect to the feature set out in the appended claim.
Claims
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A thermal printer including a thermal head in which a Field Effect Transistor is connected in series to an individual heater element of each of a plurality of heater element groups which are connected in parallel with each other, and to which one capacitor for smoothing a power and eliminating a noise is connected in parallel relative to said heater element groups, said thermal head performing printing on a thermal paper, comprising:
a printing power source circuit for supplying a first given voltage of an electric power to said thermal head for performing printing;
a failure detection power source circuit for supplying a second given voltage of said electric power to said thermal head, wherein said second given voltage is lower than said first given voltage via a detecting resistor upon detecting the failure;
a failure detection circuit for detecting a presence or absence of failure of said heater element by comparing a voltage generated at opposite ends of said detecting resistor with a threshold value; and Field Effect Transistor control means for causing discharging of said capacitor by simultaneously turning on all of said Field Effect Transistors under the condition where said printing power source circuit and said failure detection power supply circuit are turned off, before said voltage is supplied from said failure detection power source circuit to said thermal head and the failure detection is performed.
a printing power source circuit for supplying a first given voltage of an electric power to said thermal head for performing printing;
a failure detection power source circuit for supplying a second given voltage of said electric power to said thermal head, wherein said second given voltage is lower than said first given voltage via a detecting resistor upon detecting the failure;
a failure detection circuit for detecting a presence or absence of failure of said heater element by comparing a voltage generated at opposite ends of said detecting resistor with a threshold value; and Field Effect Transistor control means for causing discharging of said capacitor by simultaneously turning on all of said Field Effect Transistors under the condition where said printing power source circuit and said failure detection power supply circuit are turned off, before said voltage is supplied from said failure detection power source circuit to said thermal head and the failure detection is performed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10069263A JP3068549B2 (en) | 1998-03-05 | 1998-03-05 | Thermal printer |
| JP69263/1998 | 1998-03-05 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2264417A1 CA2264417A1 (en) | 1999-09-05 |
| CA2264417C true CA2264417C (en) | 2003-07-29 |
Family
ID=13397652
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002264417A Expired - Fee Related CA2264417C (en) | 1998-03-05 | 1999-03-04 | Thermal printer |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US5951175A (en) |
| JP (1) | JP3068549B2 (en) |
| CA (1) | CA2264417C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102189812A (en) * | 2010-01-22 | 2011-09-21 | 精工爱普生株式会社 | Head element operation check mechanism, head element operation check method, and head element number check method |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5652170A (en) * | 1996-01-22 | 1997-07-29 | Micron Technology, Inc. | Method for etching sloped contact openings in polysilicon |
| JP3653219B2 (en) | 2000-10-30 | 2005-05-25 | シャープ株式会社 | Printing apparatus and communication apparatus or information processing apparatus using the same |
| US6481814B2 (en) | 2001-02-28 | 2002-11-19 | Lemark International, Inc. | Apparatus and method for ink jet printhead voltage fault protection |
| FR2840559B1 (en) * | 2002-06-05 | 2005-08-12 | A P S Engineering | THERMAL PRINTING MODULE EQUIPPED WITH SECURITY MEANS AGAINST A DEFECTIVE CONNECTION BETWEEN CONNECTORS EQUIPPED WITH THE MODULE AND THE MACHINE PROVIDED FOR EQUIPPING THEREOF |
| CN100528570C (en) * | 2004-04-16 | 2009-08-19 | 深圳赛意法微电子有限公司 | Pen fault detecting circuit of ink jet printer and method for detecting pen fault |
| US7635174B2 (en) * | 2005-08-22 | 2009-12-22 | Lexmark International, Inc. | Heater chip test circuit and methods for using the same |
| US9096072B1 (en) * | 2014-01-13 | 2015-08-04 | Toshiba Tec Kabushiki Kaisha | Thermal printer and method for checking disconnection |
| JP6750304B2 (en) * | 2016-05-24 | 2020-09-02 | セイコーエプソン株式会社 | Thermal printer and method of controlling thermal printer |
| US12337595B2 (en) | 2020-09-25 | 2025-06-24 | Hewlett-Packard Development Company, L.P. | Fluidic dies including discharge circuits |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57123073A (en) * | 1981-01-23 | 1982-07-31 | Omron Tateisi Electronics Co | Fault detecting device of thermal head |
| JPS59201878A (en) * | 1983-04-28 | 1984-11-15 | Tokyo Electric Co Ltd | thermal printer |
| JPS60159662A (en) * | 1984-01-31 | 1985-08-21 | Tokyo Electric Co Ltd | Thermal head heating element failure detection device |
| US4595935A (en) * | 1984-08-14 | 1986-06-17 | Ncr Canada Ltd. | System for detecting defective thermal printhead elements |
| JPH0630888B2 (en) * | 1985-08-29 | 1994-04-27 | 株式会社サト− | Heater circuit defect detection device for thermal print head |
| JPS6262776A (en) * | 1985-09-14 | 1987-03-19 | Sato :Kk | Thermal printing head heating circuit defect detection device |
| JPS63191657A (en) * | 1987-02-04 | 1988-08-09 | Tokyo Electric Co Ltd | How to check thermal head for disconnection |
| US4996487A (en) * | 1989-04-24 | 1991-02-26 | International Business Machines Corporation | Apparatus for detecting failure of thermal heaters in ink jet printers |
| JPH06106759A (en) * | 1992-09-28 | 1994-04-19 | Nec Corp | Thermal head |
| US5608442A (en) * | 1994-08-31 | 1997-03-04 | Lasermaster Corporation | Heating control for thermal printers |
| JPH1069263A (en) * | 1996-08-29 | 1998-03-10 | Fuji Electric Co Ltd | Automatic screen generation method based on data attribute request |
-
1998
- 1998-03-05 JP JP10069263A patent/JP3068549B2/en not_active Expired - Fee Related
-
1999
- 1999-03-02 US US09/261,019 patent/US5951175A/en not_active Expired - Fee Related
- 1999-03-04 CA CA002264417A patent/CA2264417C/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102189812A (en) * | 2010-01-22 | 2011-09-21 | 精工爱普生株式会社 | Head element operation check mechanism, head element operation check method, and head element number check method |
| CN102189812B (en) * | 2010-01-22 | 2014-08-06 | 精工爱普生株式会社 | Head element number check mechanism and head element number check method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3068549B2 (en) | 2000-07-24 |
| US5951175A (en) | 1999-09-14 |
| JPH11254722A (en) | 1999-09-21 |
| CA2264417A1 (en) | 1999-09-05 |
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