A ticket printer and printing method

Abstract

The application discloses a kind of bill printer and printing method, by obtaining the first state of first black mark sensor;Under preset condition, control printing paper along first direction empty walk paper preset distance, compare the first state and second state of first black mark sensor, in the case where first state and second state are same, then show paper sticking mark, and alarm;In the case where first state and second state are different, control printing paper along second direction empty walk paper preset distance, wherein, second direction is opposite to first direction.By the method of the application, whether printing paper and heating head can be detected to stick, and in the case where printing paper and heating head stick, show paper sticking mark, alarm, avoid user in the case where printing paper and heating head stick, print bill, and then avoid the bill printed due to printing paper and heating head stick and lead to waste ticket, use effect is good, convenient for promoting use.

Description

Technical Field

[0001] The present application relates to the field of thermal printing technology, and in particular to a receipt printer and a printing method. Background Art

[0002] Thermal printers use a thermal head to heat thermal paper, thereby printing. When printing in two colors, the thermal printer displays the printed content on the thermal paper in the order of red (R) and black (B). The thermal printer controls the amount of heat applied by the thermal head to produce the grayscale of the image. The thermal head used in a thermal printer has heating elements arranged in a linear pattern (row). The thermal printer prints one line at a time while feeding paper to the thermal head. In other words, the thermal printer controls the amount of heat applied by the heating elements for each line to print the image on the paper.

[0003] At present, thermal printers are widely used in bill printing, ticket printing and other fields. In some special industries, printing invalid tickets cannot be tolerated.

[0004] However, in the existing ticket printing process, since the thermal printer achieves the printing effect by heating the thermal paper, in a high temperature and high humidity environment, the heating head with residual heat is very easy to stick to the thermal paper. The thermal heating head is in contact with the thermal paper for a long time, causing the thermal paper and the heating head to easily stick together, which in turn causes the printed ticket to be invalid. Summary of the Invention

[0005] Based on this, in order to solve the above technical problems, a ticket printer and printing method are provided, which can avoid the printed ticket being invalid due to the adhesion of thermal paper and heating head.

[0006] In a first aspect, a receipt printer is characterized by comprising a housing, a reel, a printing module, a detection module, a control module, and an alarm module, all disposed within the housing;

[0007] Printing paper is wound on the reel, and a black mark is provided on the printing paper;

[0008] The printing module includes a cutter, a heating head, an air knife, a compressed air tank, a rubber roller, and a stepping motor. The heating head and the rubber roller are arranged relative to each other. A paper outlet hole for printing paper to pass through is provided between the heating head and the rubber roller. The compressed air tank and the stepping motor are respectively controlled by the control module.

[0009] The detection module includes a paper non-taken sensor and at least one black mark sensor, and the paper non-taken sensor and the black mark sensor are respectively connected to the control module.

[0010] Optionally, the number of the black mark sensors is two, and the two black mark sensors are respectively a first black mark sensor and a second black mark sensor.

[0011] Optionally, the alarm module is an audible and visual alarm module.

[0012] In a second aspect, a printing method of a receipt printer is characterized in that the printing method includes:

[0013] Acquire a first state of a first black mark sensor;

[0014] Under preset conditions, controlling the printing paper to feed a preset distance in a first direction, wherein the first direction is the paper output direction of the printing paper;

[0015] Acquire a second state of the first black mark sensor;

[0016] In the case where the first state is the same as the second state, a sticky paper mark is displayed and an alarm is issued;

[0017] When the first state is different from the second state, the printing paper is controlled to travel a preset distance in a second direction, wherein the second direction is opposite to the first direction.

[0018] Optionally, controlling the printing paper to feed a preset distance in the first direction under a preset condition includes:

[0019] After a first time interval after the target bill is printed, the printing paper is controlled to travel a preset distance in a first direction.

[0020] Optionally, after a first time interval after the target bill is printed, controlling the printing paper to feed a preset distance in a first direction includes:

[0021] After a first time interval after the target bill is printed, controlling the printing paper to feed empty paper along a first direction;

[0022] When the printing paper is controlled to feed in the first direction, the air knife is controlled to be in a working state;

[0023] After the printing paper travels the preset distance in the first direction, the air knife is controlled to stop working, and the printing paper is controlled to stop traveling in the first direction.

[0024] Optionally, controlling the printing paper to feed a preset distance in the first direction under a preset condition includes:

[0025] When the printer is powered on or in standby mode, the air knife is controlled to work for a preset time period at every second time interval.

[0026] Optionally, when the first state is the same as the second state, after displaying a sticky paper mark and issuing an alarm, the method further includes:

[0027] Control the printer's stepper motor to work at a preset speed and control the air knife to work.

[0028] Optionally, the method further includes:

[0029] When the actual number of forward and backward steps of the stepping motor is less than the preset number of forward and backward steps, a first detection signal of the first black mark sensor is obtained, and a second detection signal of the second black mark sensor is obtained;

[0030] When any one of the first detection signal and the second detection signal does not include a black mark signal, displaying a sticky paper mark and giving an alarm;

[0031] The present invention has at least the following beneficial effects:

[0032] The present invention includes a shell, a reel, a printing module, a detection module, a control module and an alarm module, all of which are arranged in the shell; printing paper is wound on the reel, and a black mark is set on the printing paper; the printing module includes a cutter, a heating head, an air knife, a compressed air tank, a rubber roller and a stepper motor, the heating head and the rubber roller are arranged relative to each other, and a paper outlet hole for the printing paper to pass through is set between the heating head and the rubber roller, and the compressed air tank and the stepper motor are respectively controlled by the control module; the detection module includes a paper non-taken sensor and at least one black mark sensor, and the paper non-taken sensor and the black mark sensor are respectively connected to the control module. Through the ticket printer of the present application, the black mark on the printing paper can be detected by the black mark sensor, and then whether the printing paper and the heating head are adhered, and when the printing paper and the heating head are adhered, an alarm can be issued to prevent the user from printing the ticket when the printing paper and the heating head are adhered, thereby preventing the printed ticket from being invalid due to the adhesion between the printing paper and the heating head. The use effect is good and it is easy to promote and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic flow chart of a bill printing method provided by one embodiment of the present invention;

[0034] Figure 2 A schematic diagram of a process for detecting paper breakage and sticking by feeding and retracting paper according to an embodiment of the present invention;

[0035] Figure 3 A schematic diagram of thermal printing paper with black markings provided in one embodiment of the present invention;

[0036] Figure 4 A schematic diagram of a printing system provided in accordance with an embodiment of the present invention;

[0037] Figure 5 A schematic diagram of the relative positions of key components of a heating head and black marks on lottery paper provided by one embodiment of the present invention;

[0038] Among them, 1-black mark, 2-cutter, 3-heating head, 4-air knife, 5-compressed air tank, 6-1-first black mark sensor, 6-2-second black mark sensor, 7-rubber roller, 8-stepping motor, 9-printing paper, 10-control module, 11-alarm module, 12-paper not taken sensor. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0040] The bill printing method provided by this application is as follows: Figure 1 As shown, a bill printing method is provided, comprising the following steps:

[0041] Acquire a first state of a first black mark sensor;

[0042] Under preset conditions, controlling the printing paper to feed a preset distance in a first direction, wherein the first direction is the paper output direction of the printing paper;

[0043] Acquire a second state of the first black mark sensor;

[0044] In the case where the first state is the same as the second state, a sticky paper mark is displayed and an alarm is issued;

[0045] When the first state is different from the second state, the printing paper is controlled to travel a preset distance in a second direction, wherein the second direction is opposite to the first direction.

[0046] In one embodiment, controlling the printing paper to travel a preset distance in the first direction under a preset condition includes:

[0047] After a first time interval after the target bill is printed, the printing paper is controlled to travel a preset distance in a first direction.

[0048] In one embodiment, after a first time interval after the target bill is printed, controlling the printing paper to feed a preset distance in a first direction includes:

[0049] After a first time interval after the target bill is printed, controlling the printing paper to feed empty paper along a first direction;

[0050] When the printing paper is controlled to feed in the first direction, the air knife is controlled to be in a working state;

[0051] After the printing paper travels the preset distance in the first direction, the air knife is controlled to stop working, and the printing paper is controlled to stop traveling in the first direction.

[0052] In one embodiment, controlling the printing paper to travel a preset distance in the first direction under a preset condition includes:

[0053] When the printer is powered on or in standby mode, the air knife is controlled to work for a preset time period at every second time interval.

[0054] In one embodiment, after displaying a sticky note and issuing an alarm when the first state and the second state are the same, the method further comprises:

[0055] Control the printer's stepper motor to work at a preset speed and control the air knife to work.

[0056] This embodiment obtains the first state of the first black mark sensor; under preset conditions, controls the printing paper to move empty along the first direction for a preset distance, wherein the first direction is the paper output direction of the printing paper; secondly, obtains the second state of the first black mark sensor; finally, compares the first state and the second state of the first black mark sensor. If the first state and the second state are the same, a sticky paper mark is displayed and an alarm is issued; if the first state and the second state are different, the printing paper is controlled to move empty along the second direction for a preset distance, wherein the second direction is opposite to the first direction. The method of the present application can detect whether the printing paper and the heating head are stuck, and if the printing paper and the heating head are stuck, a sticky paper mark is displayed and an alarm is issued, thereby preventing the user from printing a receipt when the printing paper and the heating head are stuck, thereby preventing the printed receipt from being invalid due to the sticking of the printing paper and the heating head. The method has good use effect and is easy to promote and use.

[0057] In one embodiment, a receipt printer is disclosed, comprising a housing, a reel, a printing module, a detection module, a control module 10 and an alarm module 11 all disposed within the housing;

[0058] The reel is wound with printing paper 9, and the printing paper 9 is provided with a black mark 1;

[0059] The printing module includes a cutter 2, a heating head 3, an air knife 4, a compressed air tank 5, a rubber roller 7 and a stepping motor 8. The heating head 3 and the rubber roller 7 are arranged relative to each other. A paper outlet hole for printing paper 9 to pass through is provided between the heating head 3 and the rubber roller 7. The compressed air tank 5 and the stepping motor 8 are respectively controlled by the control module 10.

[0060] The detection module includes a paper non-taken sensor 12 and at least one black mark sensor 6 , and the paper non-taken sensor 12 and the black mark sensor 6 are respectively connected to the control module 10 .

[0061] In one embodiment, the number of the black mark sensors 6 is two, and the two black mark sensors 6 are respectively a first black mark sensor 6 - 1 and a second black mark sensor 6 - 2 .

[0062] In one embodiment, the alarm module 11 is an audible and visual alarm module.

[0063] In one embodiment, a method is disclosed for solving the problem that during the printing process of sports lottery tickets, due to adhesion between the thermal heating head and the thermal printing paper, the printed lottery tickets become invalid, causing losses to the lottery operator.

[0064] In one embodiment, after the lottery ticket is printed and the paper is cut, the printing process is not terminated immediately, but after a short time T, the paper is continued to be fed forward for a fixed distance. Figure 2 ] In L3, after the front paper feeding is completed, it retreats L3 distance and the lottery paper returns to its original position. At the same time, the black mark sensor 1 detects the movement of the black mark on the lottery paper. During the entire paper feeding process, the MCU determines whether paper sticking occurs by calculating the AD sampling value of the black mark sensor 1.

[0065] In one embodiment, an air knife is applied during the paper feeding process. After the air knife is applied, it is helpful to quickly release the high-temperature energy generated on the heating head during the thermal printing process, and it is also helpful for the thermal paper to break free from the heating head.

[0066] In one embodiment, the printer performs a breakaway process every t time interval when the printer is powered on and in an idle state.

[0067] In one embodiment, when paper sticking occurs, the stepper motor increases the torque by reducing the speed and applies the air knife to break free. After the paper is successfully broken free, the thermal paper returns to the initial position through black mark positioning, and the control unit clears the sticky paper mark.

[0068] In one embodiment, the stepper motor is controlled to continue to move the paper forward for a fixed distance. Figure 2 ] In L3, during the paper feeding process, the accuracy of the paper feeding is detected by the black mark sensor 1. When the paper feeding is inaccurate, the control unit sets a sticky paper mark and triggers an audible and visual alarm.

[0069] like Figure 2 and Figure 4As shown, the control unit 10 controls the stepper motor 8 to advance the paper for a distance of L3, until the black mark reaches the position above the black mark sensor 1. When the black mark completely blocks the black mark sensor 1, the state of the black mark sensor 1 changes and can be recognized by the control unit 10, indicating that no paper sticking has occurred. Otherwise, if the black mark does not reach the top of the black mark sensor 1, the state of the black mark sensor 1 does not change, or the AD sampling value does not reach the threshold, the control unit 10 sets the sticking mark and issues an alarm through the sound and light alarm module 11. Similarly, during the process of rewinding the lottery paper, the control unit 10 controls the stepper motor 8 to advance the paper for a distance of L3, after which the black mark returns to its original position. The state of the black mark sensor 1 changes again. If the AD sampling value is below the threshold, no paper sticking has occurred. Otherwise, if paper sticking has occurred, the control unit 10 sets the sticking mark and issues an alarm through the sound and light alarm module 11.

[0070] In one embodiment, when the thermal paper and the heating head are stuck together, it can be detected, an alarm can be generated, an error record can be made, and an error report can be sent. The alarm is sent by the sound and light alarm module 11. The error record is achieved by setting the variable StickState in the MCU to true. Before and after each ticket printing, the host computer sends a printer status query instruction. When the sticky paper mark is set, the ticket printing is invalid and reported to the server. After the server determines that the printing has produced an invalid ticket, it resends the printing instruction until a normal lottery ticket is printed, forming a closed loop.

[0071] In one embodiment, a technical solution to reduce paper sticking is proposed. After the lottery ticket data is printed, a time interval of milliseconds, T, is added by adding an idle paper feed and applying a heat dissipation airflow. T is kept as short as possible to dissipate the high temperature generated by the thermal heating plate during the printing process as quickly as possible through the idle paper feed, thereby preventing the heat from being concentrated at a fixed location on the thermal paper and causing paper sticking. After the lottery ticket is printed, the stepper motor is controlled to continue feeding the paper forward for a fixed distance. Figure 2 ] In L3, during the paper feeding process, the air knife applies a cooling airflow between the rubber roller and the thermal paper to accelerate the heat dissipation of the heating plate. During the whole process, the accuracy of the paper feeding is detected by the black mark sensor 1. When the paper feeding is inaccurate, the control unit sets a sticky paper mark and triggers an audible and visual alarm.

[0072] like Figure 2As shown, the control unit 10 controls the stepper motor 8 to advance the paper for a distance of L3, and the black mark reaches the position above the black mark sensor 1. When the black mark completely blocks the black mark sensor 1, the state of the black mark sensor 1 changes and can be recognized by the control unit 10, indicating that no paper sticking has occurred. Otherwise, if the black mark does not reach the top of the black mark sensor 1, the state of the black mark sensor 1 does not change, or the AD sampling value does not reach the threshold, the control unit 10 sets the paper sticking mark and issues an alarm through the sound and light alarm module 11. When no paper sticking has occurred, the control unit 10 controls the stepper motor 8 to retract the paper for a distance of L3, and the black mark returns to its original position. The state of the black mark sensor 1 changes again. If the AD sampling value is lower than the threshold, no paper sticking has occurred. Otherwise, if paper sticking has occurred, the control unit 10 sets the paper sticking mark and issues an alarm through the sound and light alarm module 11.

[0073] The second technical solution to reduce paper sticking is to perform a break-away operation every t time interval when the printer is powered on and in idle state. The operation process of the first technical solution is repeated every t time interval.

[0074] The third technical solution to reduce paper sticking is that when paper sticking occurs, the stepper motor increases the torque by reducing the speed, and at the same time applies an air knife to break free. After the paper is successfully broken free, the thermal paper returns to its initial position through black mark positioning, and the control unit clears the sticky paper mark.

[0075] The solution for detecting the paper sticking status during printing is that if both black mark sensors detect black marks within the specified number of steps of the stepper motor, it is considered that no paper sticking has occurred. Otherwise, paper sticking has occurred and the control unit sets the paper sticking mark.

[0076] When the lottery ticket is not stuck to the thermal head, sensor 1 should be able to detect the black mark on the lottery ticket after normal paper feeding L3, and sensor 2 should be able to detect the black mark on the lottery ticket after normal paper feeding L5-L4. If the lottery ticket is slightly stuck, the stepper motor will need to rotate for an additional period of time before the thermal paper starts feeding. The length of the printer's paper feeding steps will be greater than L3 or L5-L4. The degree of ticket compression can be calculated based on the difference.

[0077] The report of sticky paper occurs. Before and after each ticket printing, the host computer sends a printer status query command. When the sticky paper mark is set, the ticket printing is invalid and reported to the server. After the server determines that the printing has produced an invalid ticket, it resends the printing command until a normal lottery ticket is printed, forming a closed loop. Figure 4 ] As shown in FIG, the printer, the host computer and the remote server form a closed-loop control circuit.

[0078] The rights and interests described in this embodiment are not limited to the two black mark sensors, nor are they limited to the relative positions of the two black mark sensors. The use of 1 to N black mark sensors to implement Technical Solution 1 and Technical Solution 2 are both within the scope of protection of this patent.

[0079] The black mark sensor 1 for detecting whether paper sticking occurs can also be placed near the paper outlet, such as Figure 5 , 12- the position of the single sensor. You can also use the 12- single sensor to detect whether paper sticking occurs directly, but use the AD sampling value of the 12- single sensor instead of the AD sampling value of the black mark sensor 1 to achieve the same control logic.

[0080] Startup sticking detection process. After the printer completes the self-test after startup, it first performs the paper feed operation. During the paper feeding process, Sensor1 is used to detect the black mark. If the black mark is still not detected after feeding L3 black mark length, the buzzer beeps, the status is set to sticking error, and the variable StickState in the MCU is set to true. When the host computer sends a command to read the status, the sticking error will be detected.

[0081] After successful detection, the lottery paper is returned, and the return distance is L3. After the return is completed, the sensor 1 is checked to see whether the black mark of the lottery ticket has left the detection range of the sensor 1. If the black mark is not detected to have left the detection range, the buzzer sounds, and the status is set to sticky paper error. The variable StickState in the MCU is set to true. When the host computer sends a command to read the status, the sticky paper error will be detected.

[0082] During idle state, when the last ticket is cut, the printer enters the idle state and the idle state timer t2 starts.

[0083] When t2>t1, the paper feed command is executed, and the paper feed distance is L3. After the paper feed is completed, sensor1 detects the black mark. If the detection fails, the state is set to paper jam error, the variable StickState in the MCU is set to true, and the buzzer beeps. If the detection is successful, the paper jam error state is cleared and the variable StickState is set to false.

[0084] Lottery ticket sticking detection process during printing

[0085] After detecting a paper sticking error using the status detection function before printing begins, the host computer will interrupt the lottery sale and not submit the transaction to the background database, thus avoiding damaged tickets and reducing losses for lottery operators.

[0086] When the host computer needs to print, first check the printer status:

[0087] If the printer is in a state of ticket sticking error or other errors, it will directly return an error without performing subsequent detection; otherwise, it will send a print instruction to print the lottery ticket.

[0088] When the lottery ticket is not stuck to the thermal head, sensor 2 should be able to detect the black mark on the lottery ticket after the paper feeds normally for L5-L4. If the lottery ticket is slightly stuck, the stepper motor will rotate for an additional period of time before the thermal paper starts feeding. The printer's paper feed length will be greater than L5-L4. The difference can be used to calculate the degree of compression on the ticket.

[0089] A. When printing starts, the print length count value is cleared. At this time, the lottery black mark is between the positions Sensor1Pos and Sensor2Pos.

[0090] B. Every time the paper moves, the length of the dot line increases by 1. At the same time, sensor 2 detects the black mark on the lottery ticket. When the black mark is detected, the length counting stops.

[0091] C. After paper cutting is completed, read the count value length to determine whether there is print compression.

[0092] If |length-(L5-L4)|<8, it means the paper feed is normal and the error is within the allowable range.

[0093] If |length-(L5-L4)|>8&&(length-(L5-L4))<24, it means that the characters in the first line are compressed.

[0094] If (length-(L5-L4))<24&&(length-(L5-L4))<8*50, it means that the ticket header is compressed and some content is lost.

[0095] If (length-(L5-L4))>8*50, it means that the face value is severely compressed.

[0096] When the ticket sticking problem cannot be automatically corrected, you need to clear the error state by opening the cover, pulling out the paper, and closing the cover.

[0097] The black mark sensor 1 for detecting whether paper sticking occurs is characterized in that the black mark sensor 1 for detecting whether paper sticking occurs can also be placed near the paper outlet or reused with an unpicked single sensor, and the change in the state of the black mark is replaced by detecting the change in the presence or absence of paper.

[0098] It should be understood that although Figure 1The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. In addition, Figure 1 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The order of execution of these steps or stages is not necessarily one by one, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0099] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0100] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A bill printing method, characterized in that: The ticket printing method is applied to a ticket printer, which comprises a housing, a reel, a printing module, a detection module, a control module (10), and an alarm module (11) all arranged in the housing; Printing paper (9) is wound on the reel, and a black mark (1) is provided on the printing paper (9); The printing module comprises a cutter (2), a heating head (3), an air knife (4), a compressed air tank (5), a rubber roller (7) and a stepping motor (8); the heating head (3) and the rubber roller (7) are arranged relative to each other; a paper outlet hole for printing paper (9) to pass through is provided between the heating head (3) and the rubber roller (7); the compressed air tank (5) and the stepping motor (8) are respectively controlled by the control module (10); The detection module comprises a paper-not-taken sensor (12) and at least one black mark sensor, and the paper-not-taken sensor (12) and the black mark sensor are respectively connected to the control module (10); There are two black mark sensors, and the two black mark sensors are respectively a first black mark sensor (6-1) and a second black mark sensor (6-2); The method comprises: Acquiring a first state of a first black mark sensor (6-1); Under preset conditions, controlling the printing paper (9) to move along a first direction for a preset distance, wherein the first direction is the paper output direction of the printing paper (9); Acquiring a second state of the first black mark sensor (6-1); In the case where the first state is the same as the second state, a sticky paper mark is displayed and an alarm is issued; When the first state is different from the second state, the printing paper (9) is controlled to travel a preset distance in a second direction, wherein the second direction is opposite to the first direction; When the actual number of forward and backward steps of the stepping motor (8) is less than the preset number of forward and backward steps, a first detection signal of the first black mark sensor (6-1) is obtained, and a second detection signal of the second black mark sensor (6-2) is obtained; When any one of the first detection signal and the second detection signal does not include a black mark signal, a sticker mark is displayed and an alarm is issued.

2. A bill printing method according to claim 1, characterized in that: The alarm module (11) is an audible and visual alarm module.

3. The method according to claim 1, characterized in that The method of controlling the printing paper to travel a preset distance in a first direction under a preset condition includes: After a first time interval when the target bill is printed, the printing paper (9) is controlled to move along a first direction for a preset distance.

4. The method according to claim 3, characterized in that The step of controlling the printing paper to feed a preset distance in a first direction after a first time interval after the target bill is printed comprises: After a first time interval when the target bill is printed, controlling the printing paper (9) to feed empty paper along a first direction; When the printing paper (9) is controlled to be fed in the first direction, the air knife (4) is controlled to be in a working state; After the printing paper (9) travels the preset distance in the first direction, the air knife (4) is controlled to stop working, and the printing paper (9) is controlled to stop traveling in the first direction.

5. The method according to claim 1, wherein The method of controlling the printing paper to travel a preset distance in a first direction under a preset condition includes: When the printer is turned on or in a standby state, the air knife (4) is controlled to work for a preset time period at every second time interval.

6. The method according to claim 1, characterized in that When the first state is the same as the second state, a sticky paper mark is displayed and an alarm is issued, and the method further includes: The stepping motor (8) of the printer is controlled to operate at a preset speed and the air knife (4) is controlled to operate.

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