阅读说明：本技术 一种打印机的电源控制电路、方法和打印机 (Power supply control circuit and method of printer and printer ) 是由 赵海军 林喆 于 2021-09-17 设计创作，主要内容包括：本发明属于打印机领域,公开了打印机的电源控制电路、方法和打印机,包括：电源模块与电源控制模块电连接,在所述电源控制模块的控制下为打印机提供工作电压；电源控制模块还与打印机的处理器及打印头电连接,接收并识别打印机的处理器的工作信号,当识别出打印机的处理器工作异常时关闭输出给打印头的电源电压,使得打印头停止工作；当判定打印机的处理器处于正常工作状态时导通输出给打印头的电源电压,使得打印头正常工作；放电模块与打印机的处理器以及打印头电连接,当打印机打印完成后泄放打印头的残留电压。在处理器异常时快速关闭打印头和马达电源,停止打印停止走纸后快速泄放打印头上的残留电压,降低打印头的故障率并减少安全隐患。(The invention belongs to the field of printers, and discloses a power supply control circuit and method of a printer and the printer, which comprises the following steps: the power supply module is electrically connected with the power supply control module and provides working voltage for the printer under the control of the power supply control module; the power supply control module is also electrically connected with the processor of the printer and the printing head, receives and identifies a working signal of the processor of the printer, and closes the power supply voltage output to the printing head when the processor of the printer is identified to work abnormally so as to stop the printing head; when the processor of the printer is judged to be in a normal working state, the power supply voltage output to the printing head is conducted, so that the printing head works normally; the discharging module is electrically connected with a processor of the printer and the printing head, and when the printer finishes printing, the residual voltage of the printing head is discharged. When the processor is abnormal, the printing head and the motor power supply are quickly turned off, the residual voltage on the printing head is quickly released after the printing is stopped and the paper feeding is stopped, the failure rate of the printing head is reduced, and the potential safety hazard is reduced.)

1. A power control circuit for a printer, comprising:

the power supply module is electrically connected with the power supply control module and is used for providing working voltage for the printer under the control of the power supply control module;

the power supply control module is also electrically connected with the processor of the printer and the printing head and is used for receiving and identifying a working signal of the processor of the printer, and when the processor of the printer is identified to work abnormally, the power supply voltage output to the printing head is closed, so that the printing head stops working; when the processor of the printer is judged to be in a normal working state, the power supply voltage output to the printing head is conducted, so that the printing head works normally;

and the discharging module is electrically connected with the processor of the printer and the printing head and used for discharging residual voltage on the printing head after the printing of the printer is finished.

2. The power control circuit of a printer according to claim 1, further comprising:

the rectification module is electrically connected with the processor of the printer and the power supply control module and is used for receiving a constant level output by the processor of the printer when the processor is abnormal and discharging the voltage of the enabling control end of the power supply control module to zero volt;

the rectification module is further used for receiving a normal working signal output by the processor and outputting a second preset voltage to an enabling control end of the power control module when the processor works normally;

the power supply control module is used for closing the power supply voltage output to the printing head when the voltage received by the enabling control end of the power supply control module is smaller than a first preset voltage, so that the printing head stops working; wherein the first preset voltage is less than the second preset voltage.

3. The power control circuit of a printer according to claim 2, wherein the rectifying module comprises:

the charging rectification circuit is electrically connected with the processor of the printer and used for receiving the PWM control signal output by the processor of the printer and carrying out charging rectification when the processor of the printer works normally;

the voltage stabilizing and discharging circuit is connected with the charging and rectifying circuit and the power supply control module and is used for discharging the voltage of the enabling control end of the power supply control module to zero volt based on a constant level signal output by the printer when the processor is abnormal; or, when the processor of the printer works normally, the voltage signal output by the charging rectification circuit is stabilized and then provided to the enabling control end of the power control module.

4. The power control circuit of the printer according to claim 3, wherein the charging rectification circuit includes: the charging capacitor, the first rectifying diode and the second rectifying diode;

the first end of the charging capacitor is connected with the processor of the printer, the second end of the charging capacitor is electrically connected with the negative electrode end of the first rectifying diode, and the output end of the charging capacitor is connected with the positive electrode end of the second rectifying diode;

the positive end of the first rectifying diode is grounded;

and the negative end of the second rectifier diode is connected with the voltage stabilizing discharge circuit.

5. The power control circuit of the printer according to claim 4, wherein the voltage stabilizing discharge circuit comprises: a voltage stabilizing discharge capacitor and a voltage stabilizing discharge resistor;

the first end of the voltage stabilizing discharge capacitor is electrically connected with the negative electrode end of the second rectifier diode, the first end of the voltage stabilizing discharge capacitor is also connected with the first end of the voltage stabilizing discharge resistor, and the second end of the voltage stabilizing discharge capacitor is grounded;

the first end of the voltage stabilizing discharge resistor is also electrically connected with the enabling control end of the power control module, and the second end of the voltage stabilizing discharge resistor is grounded.

6. The power control circuit of a printer according to any one of claims 2 to 5, wherein the power control module comprises: the DCDC step-down circuit comprises:

the power input end of the voltage reduction chip is electrically connected with the power module, the enabling control end of the voltage reduction chip is electrically connected with the rectifying module, and the voltage output end of the voltage reduction chip is electrically connected with the printing head;

and the feedback circuit is respectively electrically connected with the voltage reduction chip and the printing head and is used for acquiring the voltage information provided by the voltage reduction chip to the printing head and feeding the acquired voltage information back to the voltage reduction chip.

7. The power control circuit of a printer according to any one of claims 2 to 5, wherein the power control module comprises:

the MOS tube control circuit comprises a first control MOS tube, a second control MOS tube, a first resistor, a second resistor and a first capacitor;

the grid electrode of the first control MOS tube is electrically connected with the output end of the rectification module, the source electrode of the first control MOS tube is grounded, and the drain electrode of the first control MOS tube is electrically connected with the grid electrode of the second control MOS tube through the first resistor;

and the source electrode of the second control MOS tube is electrically connected with the power supply module through the second resistor and the first capacitor which are connected in parallel, and the drain electrode of the second control MOS tube is electrically connected with the printing head.

8. The power control circuit of the printer according to claim 1, wherein the discharging module includes:

the device comprises a first discharge triode, a second discharge triode, a first discharge capacitor, a second discharge capacitor, a first discharge resistor, a second discharge resistor and a third discharge resistor;

the grid electrode of the first discharge triode is electrically connected with a processor of the printer through the first discharge capacitor and the first discharge resistor;

the source electrode of the first discharge triode is grounded;

the drain electrode of the first discharge triode is electrically connected with the grid electrode of the second discharge triode through the second discharge capacitor and the second discharge resistor and is electrically connected with the voltage input end of the printing head;

the source electrode of the second discharge triode is electrically connected with the voltage input end of the printing head;

and the drain electrode of the second discharge triode is grounded.

9. The power control circuit of a printer according to claim 8, wherein the discharging module further comprises: a fourth discharge resistor; the first end of the fourth discharge resistor is electrically connected with the printing head, the power supply control module and the source electrode of the second discharge triode; and the second end of the fourth discharge resistor is electrically connected with the second discharge capacitor and the grid electrode of the second discharge triode through the second discharge resistor.

10. A printer, comprising: a power control circuit for a printer according to any one of claims 1 to 9.

11. A power supply control method for a printer, comprising:

receiving a working signal of a processor of the printer;

identifying a working signal of a processor of the printer, and judging whether the processor of the printer is in a normal working state;

when the processor of the printer is judged to be in an abnormal working state, the power supply voltage output to the printing head is closed, so that the printing head stops working;

when the processor of the printer is judged to be in a normal working state, the power supply voltage output to the printing head is conducted, so that the printing head works normally;

and when the printer finishes printing, discharging the residual voltage on the printing head.

Technical Field

The invention relates to the field of printers, in particular to a power supply control circuit and method of a printer and the printer.

Background

In various current thermal printing products, the bad occupation ratio of a printing head is high, particularly, the conditions of application scenes are severe, for example, in places with high temperature and humidity, and due to the existence of residual voltage, the corrosion of the printing head can be accelerated, and dead spots are generated to damage the printing head. Or the printing head and the motor are heated seriously and burnt out due to the fact that the printing head power supply and the motor power supply are not turned off in time due to abnormal control of the processor, and potential safety hazards are generated.

Existing solutions risk not shutting down the power to the printhead and motor when the microprocessor is abnormally uncontrolled. At the moment, when the heating point gating signal is effective, the printing head can be damaged, because the heating dot matrix has the longest bearable starting time, such as 1.3-2.5 milliseconds; when the power is continuously supplied to the heating sheet, the printing head can be heated seriously, and potential safety hazards are generated; if the control signal of the motor driving chip is effective, the motor is electrified for a long time, the temperature of the motor rises rapidly after a few minutes, surrounding plastics are melted, and potential safety hazards are also generated.

Disclosure of Invention

The invention aims to provide a power supply control circuit and method of a printer and the printer, and solves the problems.

The technical scheme provided by the invention is as follows:

in one aspect, there is provided a power control circuit of a printer, including:

the power supply module is electrically connected with the power supply control module and is used for providing working voltage for the printer under the control of the power supply control module;

the power supply control module is also electrically connected with the processor of the printer and the printing head and is used for receiving and identifying a working signal of the processor of the printer, and when the processor of the printer is identified to work abnormally, the power supply voltage output to the printing head is closed, so that the printing head stops working; when the processor of the printer is judged to be in a normal working state, the power supply voltage output to the printing head is conducted, so that the printing head works normally;

and the discharging module is electrically connected with the processor of the printer and the printing head and used for discharging residual voltage on the printing head after the printing of the printer is finished.

Further preferably, the method further comprises the following steps:

the rectification module is electrically connected with the processor of the printer and the power supply control module and is used for receiving a constant level output by the processor of the printer when the processor is abnormal and discharging the voltage of the enabling control end of the power supply control module to zero volt;

the rectification module is further used for receiving a normal working signal output by the processor and outputting a second preset voltage to an enabling control end of the power control module when the processor works normally;

the power supply control module is used for closing the power supply voltage output to the printing head when the voltage received by the enabling control end of the power supply control module is smaller than a first preset voltage, so that the printing head stops working; wherein the first preset voltage is less than the second preset voltage.

Further preferably, the rectifier module includes:

the charging rectification circuit is electrically connected with the processor of the printer and used for receiving the PWM control signal output by the processor of the printer and carrying out charging rectification when the processor of the printer works normally;

the voltage stabilizing and discharging circuit is connected with the charging and rectifying circuit and the power supply control module and is used for discharging the voltage of the enabling control end of the power supply control module to zero volt based on a constant level signal output by the printer when the processor is abnormal; or, when the processor of the printer works normally, the voltage signal output by the charging rectification circuit is stabilized and then provided to the enabling control end of the power control module.

Further preferably, the charging rectification circuit includes: the charging capacitor, the first rectifying diode and the second rectifying diode;

the first end of the charging capacitor is connected with the processor of the printer, the second end of the charging capacitor is electrically connected with the negative electrode end of the first rectifying diode, and the output end of the charging capacitor is connected with the positive electrode end of the second rectifying diode;

the positive end of the first rectifying diode is grounded;

and the negative end of the second rectifier diode is connected with the voltage stabilizing discharge circuit.

Further preferably, the voltage stabilizing discharge circuit includes: a voltage stabilizing discharge capacitor and a voltage stabilizing discharge resistor;

the first end of the voltage stabilizing discharge capacitor is electrically connected with the negative electrode end of the second rectifier diode, the first end of the voltage stabilizing discharge capacitor is also connected with the first end of the voltage stabilizing discharge resistor, and the second end of the voltage stabilizing discharge capacitor is grounded;

the first end of the voltage stabilizing discharge resistor is also electrically connected with the enabling control end of the power control module, and the second end of the voltage stabilizing discharge resistor is grounded.

Further preferably, the power control module includes: the DCDC step-down circuit comprises:

the power input end of the voltage reduction chip is electrically connected with the power module, the enabling control end of the voltage reduction chip is electrically connected with the rectifying module, and the voltage output end of the voltage reduction chip is electrically connected with the printing head;

and the feedback circuit is respectively electrically connected with the voltage reduction chip and the printing head and is used for acquiring the voltage information provided by the voltage reduction chip to the printing head and feeding the acquired voltage information back to the voltage reduction chip.

Further preferably, the power control module includes:

the MOS tube control circuit comprises a first control MOS tube, a second control MOS tube, a first resistor, a second resistor and a first capacitor;

the grid electrode of the first control MOS tube is electrically connected with the output end of the rectification module, the source electrode of the first control MOS tube is grounded, and the drain electrode of the first control MOS tube is electrically connected with the grid electrode of the second control MOS tube through the first resistor;

and the source electrode of the second control MOS tube is electrically connected with the power supply module through the second resistor and the first capacitor which are connected in parallel, and the drain electrode of the second control MOS tube is electrically connected with the printing head.

Further preferably, the discharge module includes:

the device comprises a first discharge triode, a second discharge triode, a first discharge capacitor, a second discharge capacitor, a first discharge resistor, a second discharge resistor and a third discharge resistor;

the grid electrode of the first discharge triode is electrically connected with a processor of the printer through the first discharge capacitor and the first discharge resistor;

the source electrode of the first discharge triode is grounded;

the drain electrode of the first discharge triode is electrically connected with the grid electrode of the second discharge triode through the second discharge capacitor and the second discharge resistor and is electrically connected with the voltage input end of the printing head;

the source electrode of the second discharge triode is electrically connected with the voltage input end of the printing head;

and the drain electrode of the second discharge triode is grounded.

Further preferably, the discharge module further includes: a fourth discharge resistor; the first end of the fourth discharge resistor is electrically connected with the printing head, the power supply control module and the source electrode of the second discharge triode; and the second end of the fourth discharge resistor is electrically connected with the second discharge capacitor and the grid electrode of the second discharge triode through the second discharge resistor.

A printer, comprising: the power control circuit of the printer.

A power supply control method of a printer, comprising:

receiving a working signal of a processor of the printer;

identifying a working signal of a processor of the printer, and judging whether the processor of the printer is in a normal working state;

when the processor of the printer is judged to be in an abnormal working state, the power supply voltage output to the printing head is closed, so that the printing head stops working;

when the processor of the printer is judged to be in a normal working state, the power supply voltage output to the printing head is conducted, so that the printing head works normally;

and when the printer finishes printing, discharging the residual voltage on the printing head.

The power supply control circuit and method of the printer and the printer provided by the invention at least have the following technical effects:

the invention can quickly close the printing head and the motor power supply when the processor is abnormal by controlling the enabling control signal of the power supply chip, and simultaneously, after the printing is stopped and the paper feeding is stopped, the discharging circuit of the VPRT is added to quickly discharge the residual voltage on the printing head. The invention can greatly reduce the failure rate of the printing head and reduce the potential safety hazard.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a schematic diagram of one embodiment of a power control circuit for a printer of the present invention;

FIG. 2 is a schematic diagram of another embodiment of a power control circuit of a printer of the present invention;

FIG. 3 is a schematic diagram of another embodiment of a power control circuit of a printer of the present invention;

FIG. 4 is a schematic diagram of another embodiment of a power control circuit for a printer according to the present invention

FIG. 5 is a schematic diagram of another embodiment of a power control circuit for a printer of the present invention;

fig. 6 is a schematic diagram of one embodiment of a power supply control method of a printer of the present invention.

Detailed Description

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

In this context, it is to be understood that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

A Thermal Printer (Thermal Printer Mechanism) is a Printer that can print characters and patterns on Thermal paper with a heated dot matrix.

Print head dead pixels (Bad heats Elements) refer to: abnormal impedance, and failure to generate heat.

The Motor (Motor) means: the starter rotor is driven to rotate by the forced rotation of the electrified coil in the magnetic field, the large gear and the roller wheel are driven by the small gear on the rotor, and the roller wheel discharges the thermal paper according to the set steps.

The general purpose input/output (GPIO) port refers to a general purpose input/output pin of a microprocessor MCU or a central processing unit CPU, etc., and can be set in high and low levels, etc. to control peripheral circuits.

Example one

In one aspect, as shown in fig. 1, the present invention provides a power control circuit for a printer, including:

and the power supply module 100 is electrically connected with the power supply control module and is used for providing working voltage for the printer under the control of the power supply control module.

Specifically, in the present embodiment, the power module 100 provides a working voltage for the printer to ensure that the printer can operate under a stable voltage.

The power control module 200 is further electrically connected to the processor of the printer and the print head, and is configured to receive and recognize a working signal of the processor of the printer, and when it is recognized that the processor of the printer works abnormally, turn off the power voltage output to the print head, so that the print head stops working; and when the processor of the printer is judged to be in a normal working state, the power supply voltage output to the printing head is conducted, so that the printing head works normally.

And the discharging module 300 is electrically connected with the processor of the printer and the printing head and used for discharging residual voltage on the printing head after the printing of the printer is finished.

Specifically, the discharge module is used as a discharge circuit to quickly discharge residual voltage on the printing head after stopping printing and stopping paper feeding.

The existing scheme is that an MCU microprocessor directly controls the output voltage of a DCDC voltage reduction chip by using GPIO (general purpose input/output) and then controls a PMOS (P-channel metal oxide semiconductor) tube to close or open the voltage VPRT, or directly controls an external power supply to close or open by using the PMOS tube and finally is directly connected to a printing head and a motor to supply power VPRT.

In the present embodiment, the PWM signal is sent by the processor of the printer, and when the power control module 200 receives the PWM signal (square wave signal), the output voltage of the power module 100 can be output to the print head by the power control module 200, so that the print head operates normally. When the processor of the printer is abnormal, the power supply control circuit receives the constant level signal and enables the power supply input of the printing head to be closed so as to enable the printing head to stop working.

If such a power supply enable control circuit in the present embodiment is not used and the port (VPRT _ EN _ PWM) of the GPIO of the processor is directly connected to the port (VPRT _ EN), there is a certain probability that the power supply VPRT output to the printhead and the motor is always on when the processor is abnormal. At this time, if the heating head chip gating signal is effective, the heating head chip can be damaged. The longest bearable starting heating time of each heating point of the heating head piece is about 1.3-2.5 milliseconds; when the heating sheet is continuously supplied with power, the printing head can be heated seriously, and serious potential safety hazard is generated. If the control signal of the motor driving chip is effective, the motor is electrified for a long time, the temperature of the motor rises rapidly after a few minutes, surrounding plastics are melted, and potential safety hazards are also generated.

In this embodiment, the present invention has two improvements: the first protection point, the enable control signal of the power chip, when the processor is abnormal, the printing head and the motor power supply can be quickly closed, the other protection point is added with a VPRT discharge circuit after the printing is stopped and the paper feeding is stopped, and the residual voltage on the printing head is quickly released.

Example two

Based on the foregoing embodiments, as shown in fig. 2 and 3, parts of this embodiment that are the same as those of the foregoing embodiments are not repeated, and this embodiment provides a power control circuit for a printer, including: a power supply module 100, a power supply control module 200, and a discharge module 300.

And the rectification module is electrically connected with the processor of the printer and the power control module, and is used for receiving the constant level output by the processor of the printer and discharging the voltage of the enabling control end of the power control module to zero volt when the processor is abnormal.

And the rectification module is also used for receiving a normal working signal output by the processor and outputting a second preset voltage to the enabling control end of the power control module when the processor works normally.

The power supply control module is used for closing the power supply voltage output to the printing head when the voltage received by the enabling control end of the power supply control module is smaller than a first preset voltage, so that the printing head stops working; wherein the first preset voltage is less than the second preset voltage.

Specifically, the first preset voltage signal may include a voltage signal of 0.4V, and the second preset voltage signal may include a voltage signal of 0.8V. And when the power supply control module receives a voltage signal less than or equal to 0.4V, the output is closed, and when the power supply control module receives a voltage signal greater than or equal to 0.8V, the output is opened, and the voltage is output to the printing head. The print head may comprise a print head of a thermal printer.

Wherein, the rectifier module includes:

and the charging rectification circuit is electrically connected with the processor of the printer and used for receiving the PWM control signal output by the processor of the printer and carrying out charging rectification when the processor of the printer works normally.

The voltage stabilizing and discharging circuit is connected with the charging and rectifying circuit and the power supply control module and is used for discharging the voltage of the enabling control end of the power supply control module to zero volt based on a constant level signal output by the printer when the processor is abnormal; or, when the processor of the printer works normally, the voltage signal output by the charging rectification circuit is stabilized and then provided to the enabling control end of the power control module.

Illustratively, the charging rectification circuit includes: a charging capacitor (C2), a first rectifying diode, and a second rectifying diode.

Wherein the first rectifying diode and the second rectifying diode constitute a device (D1).

The first end of the charging capacitor (C2) is connected with a processor of the printer, the second end of the charging capacitor (C2) is electrically connected with the negative electrode end of the first rectifying diode, and the output end of the charging capacitor (C2) is connected with the positive electrode end of the second rectifying diode.

And the positive end of the first rectifying diode is grounded.

And the negative end of the second rectifier diode is connected with the voltage stabilizing discharge circuit.

The voltage stabilizing discharge circuit comprises: a voltage-stabilizing discharge capacitor (C8) and a voltage-stabilizing discharge resistor (R1).

The first end of the voltage stabilizing discharge capacitor (C8) is electrically connected with the negative electrode end of the second rectifier diode, the first end of the voltage stabilizing discharge capacitor (C8) is also connected with the first end of the voltage stabilizing discharge resistor (R1), and the second end of the voltage stabilizing discharge capacitor (C8) is grounded.

The first end of the voltage stabilizing discharge resistor (R1) is also electrically connected with the enable control end (VPRT _ EN) of the power control module 200, and the second end of the voltage stabilizing discharge resistor (R1) is grounded.

In the embodiment, the selection and processing of the PWM signal or the constant level signal output by the processor of the printer are realized by the rectifying module, so that the power control module can prepare to identify whether the processor of the printer is working normally, and then control the power input of the print head.

EXAMPLE III

Based on the foregoing embodiments, as shown in fig. 3 and 4, parts of this embodiment that are the same as those of the foregoing embodiments are not repeated, and this embodiment provides a power control circuit for a printer, including: a power supply module 100, a power supply control module 200, and a discharge module 300.

Wherein, the power control module 200 includes: the DCDC step-down circuit comprises:

the voltage reduction chip is characterized in that a power input end of the voltage reduction chip is electrically connected with the power module, an enabling control end of the voltage reduction chip is electrically connected with the rectifying module, and a voltage output end of the voltage reduction chip is electrically connected with the printing head.

The power input end (IN) of the voltage reduction chip (U1) is connected with a power supply, the enable control End (EN) of the voltage reduction chip (U1) is connected with the port (VPRT _ EN) of the rectifying module 100, and the voltage output end (VPRT) of the voltage reduction chip (U1) is connected with the printing head.

Specifically, the buck chip (U1) is further grounded through a capacitor (C9), a port (GND) of the buck chip (U1) is grounded, and a port (ILMT) of the buck chip (U1) is grounded through a resistor (R2).

The Port (PG) of the buck chip (U1) is connected to the port (SYS _3.3V) through a resistor (R3), and the Port (PG) of the buck chip (U1) is connected to the port (VPRT _ PGOOD _ INT).

Illustratively, as shown in fig. 3, the rectifying module 400 is connected to an enable control signal port (EN) of the buck chip (U1). The input end of the charging capacitor (C2) is connected with the output end (VPRT _ EN _ PWM) of the processor of the printer, the output end of the charging capacitor (C2) is connected with the port (3) of the rectifying diode (D1), the port (1) of the rectifying diode (D1) is grounded, and the port (2) of the rectifying diode (D1) is connected with the voltage stabilizing discharge capacitor (C8). The other end of the voltage stabilizing discharge capacitor (C8) is grounded. One end of the voltage stabilizing discharge resistor (R1) is connected with a port (VPRT _ EN) of the DCDC voltage reducing module.

Wherein, the port (VSYS) is the power of input, generally 12 ~ 24V, inputs to DCDC step-down chip U1. Different resistors (R6 and R7) are configured according to the power supply requirements of different thermal printers, so that different voltages VPRT can be set and output to the thermal printers.

The enable control signal EN of the voltage reduction chip (U1) is a square wave signal VPRT _ EN _ PWM with a certain frequency F1 output by GPIO of the MCU/CPU, for example, F1 is 3KHz, the voltage amplitude is 3.3V, and the duty ratio is 50%; the VPRT _ EN _ PWM is charged and rectified by a charging capacitor (C2) and a rectifying diode (D1), and then is stabilized by a voltage stabilizing discharging capacitor (C8) and a voltage stabilizing discharging resistor (R1) to obtain a relatively stable voltage VPRT _ EN, which is about 2.0-2.64V. This voltage can be fine-tuned by adjusting the values of the regulated discharge capacitor (C8) and the regulated discharge resistor (R1).

And the feedback circuit is respectively electrically connected with the voltage reduction chip and the printing head and is used for acquiring the voltage information provided by the voltage reduction chip to the printing head and feeding the acquired voltage information back to the voltage reduction chip.

The feedback circuit comprises resistors (R6 and R7), and the switch enabling voltages of different DCDC voltage reduction chips are different; the port (VPRT) is set by the feedback voltage port (FB) and the feedback resistors (R6 and R7), and the formula is as follows: VPRT ═ 0.6V (R6+ R7)/R7.

For example, for a circuit with 24V down to 12V, VPRT is calculated to be 12.06V using R6-191K and R7-10K.

The DCDC voltage reduction circuit closes voltage output to the printing head when the received voltage signal output by the rectifying module is below a first preset voltage signal, or opens voltage output to the printing head when the received voltage signal output by the rectifying module is above a second preset voltage.

Specifically, the first preset voltage signal may include a voltage signal of 0.4V, and the second preset voltage signal may include a voltage signal of 0.8V. The DCDC voltage-reducing circuit turns off the output when receiving a voltage signal of 0.4V or less, turns on the output when receiving a voltage signal of 0.8V or more, and outputs a voltage to the print head. The print head may comprise a print head of a thermal printer.

The discharging module 300 receives a high level signal output by a processor of the printer after printing is completed to turn on the discharging module, discharges a residual voltage at an output port of a power control circuit of the printer to the ground through the discharging module, and pulls down a level at an input port of the discharging module to turn off the discharging module after the residual voltage is discharged.

Illustratively, a filter circuit may be included in the DCDC voltage reduction circuit, an input of the filter circuit being connected to the power supply, and an output of the filter circuit being connected to the DCDC voltage reduction circuit for filtering noise of the voltage output by the power supply.

Specifically, the filter circuit includes a filter circuit formed by capacitors (C1 to C7).

In the present embodiment, the output of the buck chip (U1) is turned off when the voltage output from the port (VPRT _ EN) is 0.4V, and the output of the buck chip (U1) is turned on when the voltage output from the port (VPRT _ EN) is 0.8V.

The switch enabling voltages of different DCDC voltage reduction chips are different; the port (VPRT) is set by the feedback voltage port (FB) and the feedback resistors (R6 and R7), and the formula is as follows: VPRT ═ 0.6V (R6+ R7)/R7.

For example, for a circuit with 24V down to 12V, VPRT is calculated to be 12.06V using R6-191K and R7-10K.

Specifically, when the processor is in an abnormal state such as a dead halt, and the printing driving software is not controlled by the processor, the port (VPRT _ EN _ PWM) cannot normally invert and output the square wave signal, the level of the square wave signal is changed to be constant, and the port (VPRT _ EN) can rapidly discharge to zero volts through the resistor (R1) and the capacitor (C8). Discharging time: t ═ R ═ C ═ 20000 ═ 4.7 ═ 10-8 ═ 0.00094 seconds.

When the voltage output from the port (VPRT _ EN) is less than 0.4V, the output port (VPRT) is closed.

If such a power supply enable control circuit in the present embodiment is not used and the port (VPRT _ EN _ PWM) of the GPIO of the processor is directly connected to the port (VPRT _ EN), there is a certain probability that the power supply VPRT output to the printhead and the motor is always on when the processor is abnormal. At this time, if the strobe signal of the heating head chip is effective, the heating head chip can be damaged. The longest bearable starting heating time of each heating point of the heating head piece is about 1.3-2.5 milliseconds; when the heating sheet is continuously supplied with power, the printing head can be heated seriously, and serious potential safety hazard is generated. If the control signal of the motor driving chip is effective, the motor is electrified for a long time, the temperature of the motor rises rapidly after a few minutes, surrounding plastics are melted, and potential safety hazards are also generated.

Note that, in the present embodiment, when the voltage output from the power supply module 100 coincides with the voltage required for the print head, the duty ratio of the PWM signal output at this time is processed by the printer is 100% so that the DCDC voltage-reducing circuit does not perform the voltage-reducing operation. For example, the voltage output by the power supply module 100 is 24V, and the voltage required by the printhead, i.e., the operating voltage, is also 24V. Alternatively, the voltage output by the power supply module 100 is 12V, and the voltage required by the printhead, i.e., the operating voltage, is also 12V. The DCDC voltage reduction circuit does not perform voltage reduction operation at this time.

Example four

Based on the foregoing embodiment, as shown in fig. 5, the same parts as those in the foregoing embodiment are not repeated in detail, and this embodiment provides a power control circuit for a printer, including: a power supply module 100, a power supply control module 200, and a discharge module 300.

The power control module 200 includes a MOS transistor control circuit including a first control MOS transistor, a second control MOS transistor, a first resistor, a second resistor, and a first capacitor.

The grid electrode of the first control MOS tube is electrically connected with the output end of the rectification module, the source electrode of the first control MOS tube is grounded, and the drain electrode of the first control MOS tube is electrically connected with the grid electrode of the second control MOS tube through the first resistor.

And the source electrode of the second control MOS tube is electrically connected with the power supply module through the second resistor and the first capacitor which are connected in parallel, and the drain electrode of the second control MOS tube is electrically connected with the printing head.

Illustratively, as shown in fig. 5, the first control MOS transistor (Q6), the second control MOS transistor (Q5), the first resistor (R13), the second resistor (R12), and the first capacitor (C17).

The grid electrode of the first control MOS tube (Q6) is electrically connected with the output end of the rectifying module, the source electrode of the first control MOS tube (Q6) is grounded, and the drain electrode of the first control MOS tube (Q6) is electrically connected with the grid electrode of the second control MOS tube (Q5) through the first resistor (R13). The source electrode of the second control MOS tube (Q5) is electrically connected with the power supply module through the second resistor (R12) and the first capacitor (C17) which are connected in parallel, and the drain electrode of the second control MOS tube (Q5) is electrically connected with the printing head.

In the present embodiment, when the VSYS voltage of the power supply module 100 is the same as the operating voltage (VPRT voltage) of the printhead, the MOS tube control circuit may be directly used.

It should be noted that, when the VSYS voltage of the power supply module 100 is not the same as the working voltage (VPRT voltage) of the printhead, a voltage reduction module may be added between the MOS transistor control circuit and the power supply module 100, so that the VSYS voltage of the power supply module 100 is the same as the working voltage (VPRT voltage) of the printhead.

EXAMPLE five

Based on the foregoing embodiments, as shown in fig. 4 and 5, parts of this embodiment that are the same as those of the foregoing embodiments are not repeated, and this embodiment provides a power control circuit for a printer, including: a power supply module 100, a power supply control module 200, and a discharge module 300.

The discharging module 300 includes:

the device comprises a first discharge triode, a second discharge triode, a first discharge capacitor, a second discharge capacitor, a first discharge resistor, a second discharge resistor and a third discharge resistor.

And the grid electrode of the first discharge triode is electrically connected with the processor of the printer through the first discharge capacitor and the first discharge resistor.

The source of the first discharge triode is grounded.

And the drain electrode of the first discharge triode is electrically connected with the grid electrode of the second discharge triode through the second discharge capacitor and the second discharge resistor and is electrically connected with the voltage input end of the printing head.

And the source electrode of the second discharge triode is electrically connected with the voltage input end of the printing head.

And the drain electrode of the second discharge triode is grounded.

Preferably, the discharge module includes: the device comprises a first discharge triode, a second discharge triode, a first discharge capacitor, a second discharge capacitor, a first discharge resistor, a second discharge resistor and a third discharge resistor.

On the power supply network of printer head and motor, during circuit design, in order to guarantee motor drive chip job stabilization, there will be some capacitive circuit usually, after stopping printing the paper feed, the circuit can close printer head and motor power, and remaining voltage discharges through the capacitive resistor, can slowly drop to zero volt, and existing design does not have special discharge circuit. In the long-term use process of the product, printing characters of a printing head become light, or certain heating points are completely damaged and printed into a white line.

Carrying out simulation test in a laboratory, printing one sheet by the machine every ten minutes at the same time, and finding that the machine has dead spots after printing lasts for several days in a high-temperature and high-humidity environment; the longer the residual voltage discharge time, the faster the printing head corrodes; the harsher the high-temperature and high-humidity environment is, the more bad points appear under the same printing condition, refer to the following table:

the above table shows the relationship between the time of occurrence of a dead pixel and the residual voltage holding time in a high-temperature and high-humidity environment.

Aiming at the defects of the traditional printer power supply circuit design, the invention provides a printer power supply enabling control circuit and a printer power supply discharging circuit, which can greatly reduce the failure rate of a printing head and reduce potential safety hazards.

By using the power supply control circuit of the printer, a specific simulation test is carried out in a laboratory, and the situation that no dead pixel appears in the printer after printing lasts for several days in a high-temperature and high-humidity environment is found; the residual voltage discharge time is short, and the printing head is basically not corroded; the harsher high temperature and high humidity environment is, the dead spots do not appear under the same printing condition, refer to the following table:

illustratively, as shown in fig. 4, a first discharge transistor (Q1), a second discharge transistor (Q2), a first discharge capacitor (C11), a second discharge capacitor (C15), a first discharge resistor (R5), a second discharge resistor (R11), and a third discharge resistor (R9).

The first discharge capacitor (C11) and the second discharge capacitor (C15) buffer the residual voltage of the printhead, thereby preventing the discharge module from being worn or damaged due to excessive residual voltage.

The grid (G) of the first discharge triode (Q1) is connected with the processor of the printer through the first discharge capacitor (C11) and the first discharge resistor (R5).

The source (S) of the first discharge transistor (Q1) is connected to ground.

The drain (D) of the first discharge transistor (Q1) is connected to the gate (G) of the second discharge transistor (Q2) through the second discharge capacitor (C15) and the second discharge resistor (R11), and is also connected to the voltage input terminal (VPRT) of the printhead.

The source (S) of the second discharge transistor (Q2) is connected to the voltage input (VPRT) of the printhead.

The drain (D) of the second discharge transistor (Q2) is connected to ground.

On this basis, as shown in fig. 4, the discharge module 300 may further include a fourth discharge resistor (R8); a first end of the fourth discharge resistor (R8) electrically connected to the printhead, the power control module, and a source of the second discharge transistor (Q2); the second end of the fourth discharging resistor (R8) is electrically connected with the gate of the second discharging triode (Q2) through the second discharging capacitor (C15) and the second discharging resistor (R11).

The input end of the discharging module is connected with the processor of the printer and used for receiving a high-level signal output by the processor of the printer, and the first discharging triode (Q1) is conducted, so that the second discharging triode (Q2) is conducted to discharge the residual voltage of the printing head to the ground.

When the residual voltage is discharged completely, a low level signal output by a processor of the printer is received, and the first discharging triode (Q1) is cut off, so that the second discharging triode (Q2) is cut off to turn off the discharging module.

Specifically, in this embodiment, after stopping printing and stopping paper feeding, a discharge circuit of VPRT is added to quickly discharge the residual voltage on the print head.

Illustratively, as shown in fig. 2, after each single normal print is finished, the level of the port (VPRT _ EN _ PWM) is pulled down, the output of the port (VPRT) is closed, the level of the port (DISCHARGE _ VPRT) is pulled up, and the bleeder circuit is opened, so that the residual voltage of VPRT is quickly discharged to the ground through the conductive MOS transistor Q2. After a certain period of time, the level of the port (DISCHARGE _ VPRT) is pulled down after the light residual voltage is completely discharged.

Through the mode, the live time of the heating head piece can be greatly shortened, the service life of the printing head is prolonged, and the effect is particularly obvious under severe working environments such as high temperature and high humidity.

When the printing is normally started, the level of the port (DISCHARGE _ VPRT) is firstly pulled down, and then the square wave of the output port (VPRT _ EN _ PWM) is output, so that the power port (VPRT) is enabled.

In the embodiment, after the printer stops printing and paper feeding, the residual voltage on the printing head can be quickly discharged through the discharging module.

EXAMPLE six

Based on the foregoing embodiment, parts of the embodiment that are the same as those of the foregoing embodiment are not repeated, and this embodiment provides a printer, including: the power control circuit of the printer.

Wherein, the power control circuit of printer includes:

and the power supply module is electrically connected with the power supply control module and is used for providing working voltage for the printer under the control of the power supply control module.

The power supply control module is also electrically connected with the processor of the printer and the printing head and is used for receiving and identifying a working signal of the processor of the printer, and when the processor of the printer is identified to work abnormally, the power supply voltage output to the printing head is closed, so that the printing head stops working; and when the processor of the printer is judged to be in a normal working state, the power supply voltage output to the printing head is conducted, so that the printing head works normally.

And the discharging module is electrically connected with the processor of the printer and the printing head and used for discharging residual voltage on the printing head after the printing of the printer is finished.

In this embodiment, the printer may comprise a thermal printer, and the processor of the printer outputs the PWM signal to the power control circuit when operating normally, and the power control circuit provides operating power to the printhead. When the processor of the printer is abnormal, the power control circuit receives a constant level signal and causes the power input of the print head to be turned off.

Meanwhile, after the printing head stops printing, the power supply control circuit releases the residual voltage of the printing head, and potential safety hazards caused by serious heating of the printing head are avoided.

In this embodiment, the enable control signal of the power supply chip of the present invention can quickly turn off the power supply to the printhead and the motor when the processor of the printer is abnormal. Meanwhile, after the printer stops printing and stops paper feeding, the residual voltage on the printing head is quickly discharged through a discharge circuit of the VPRT in the power supply control circuit. The potential safety hazard caused by serious heating of the printing head is avoided.

EXAMPLE seven

Based on the foregoing embodiment, as shown in fig. 6, parts of this embodiment that are the same as those of the foregoing embodiment are not repeated, and this embodiment provides a power control method for a printer, including:

s100 receives an operation signal of a processor of the printer.

S200, identifying a working signal of the processor of the printer, and judging whether the processor of the printer is in a normal working state.

Specifically, a power control module in the power control circuit receives a working signal of a processor of the printer. Identifying, by a power control module, a working signal of a processor of the printer. The normal operation signal of the processor of the printer is a PWM signal, and the abnormal operation signal of the processor of the printer is a constant level signal.

S300, when the processor of the printer is judged to be in the abnormal working state, the power supply voltage output to the printing head is closed, and the printing head stops working.

Specifically, when the power control module identifies that the processor of the printer works abnormally, the power supply voltage output to the printing head is turned off, so that the printing head stops working.

S400, when the processor of the printer is judged to be in a normal working state, the power supply voltage output to the printing head is conducted, and the printing head works normally.

Specifically, when the power control module determines that the processor of the printer is in a normal working state, the power voltage output to the printing head is conducted, so that the printing head works normally.

S500, after the printer finishes printing, discharging the residual voltage on the printing head.

The method of this embodiment is applied to the power control circuit, and discharges the residual voltage of the printhead to ground through a discharge module, and pulls down the level of the input port of the discharge module to turn off the discharge module after the residual voltage is discharged.

The invention can quickly close the printing head and the motor power supply when the processor is abnormal by controlling the enabling control signal of the power supply chip, and simultaneously, after the printing is stopped and the paper feeding is stopped, the discharging circuit of the VPRT is added to quickly discharge the residual voltage on the printing head. The invention can greatly reduce the failure rate of the printing head and reduce the potential safety hazard.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or recited in detail in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus/electronic device and method may be implemented in other ways. The above-described embodiments of the apparatus/electronic device are merely exemplary, and the division of the modules or units is merely an example of a logical division, and there may be other divisions when the actual implementation is performed, and for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.