Thermal printing apparatus with encryption

Abstract

The utility model relates to thermal printing head manufacturing technical field, specifically is a kind of thermal printing device with encryption function, and corresponding encryption circuit and decryption circuit are equipped on external printing host and thermal printing head, the decryption circuit is arranged on the PCB circuit board of thermal printing head, and the output end of decryption circuit is connected with the control IC, and the decryption circuit includes key one-time storage circuit, shift register and exclusive or logic chip, wherein key one-time storage circuit is connected with shift register, shift register is connected with exclusive or logic chip, the output end of exclusive or logic chip is connected with control IC, signal socket connected with the signal input end of shift register is equipped on the PCB circuit board of thermal printing head, the output end of encryption circuit is sent into decryption circuit through signal socket, and after being handled by decryption circuit, it is sent into control IC, compared with prior art, it has the advantages of reasonable structure, low cost, low energy consumption etc.

Description

Technical fields:

[0001] This utility model relates to the field of thermal printhead manufacturing technology, specifically a thermal printing device with encryption function that has a reasonable structure, low energy consumption, facilitates smooth and accurate matching of the printhead, and thus ensures printing quality. Background technology:

[0002] As is well known, the working process of a thermal printhead is that the printer transmits printing data and printing control signals to the control IC on the printhead through the data interface socket. The IC then controls the specific heating point to generate heat, and the heat is transferred to the printing medium that is in close contact with the heating element, causing the printing medium to change color and thus achieving printing.

[0003] In practical use, the thermal printhead, as a core component of a thermal printer, is also a consumable. When the printhead is incompatible with the printer model, it can lead to decreased print quality and even performance degradation, such as reduced safety and shorter lifespan of the equipment. Therefore, there is an urgent need for a technical solution that facilitates the smooth and accurate matching of the printhead with the printing equipment. Summary of the Invention:

[0004] This invention addresses the problems existing in current use by proposing a thermal printing device with a reasonable structure, reliable operation, and effective binding of the printer model and printhead model, equipped with encryption function.

[0005] This utility model achieves its purpose through the following measures:

[0006] A thermal printing device with encryption function includes an external printing host and a thermal printhead. The external printing host is connected to a control IC on the thermal printhead via a cable to achieve power supply and transmission of printing data. The device is characterized in that the external printing host and the thermal printhead are also equipped with corresponding encryption and decryption circuits. The decryption circuit is located on the PCB board of the thermal printhead, and its output is connected to the control IC. The decryption circuit includes a one-time key storage circuit, a shift register, and an XOR logic chip. The one-time key storage circuit is connected to the shift register, the shift register is connected to the XOR logic chip, and the output of the XOR logic chip is connected to the control IC. The PCB board of the thermal printhead has a signal socket connected to the signal input terminal of the shift register. The output of the encryption circuit is fed into the decryption circuit via the signal socket, and after processing by the decryption circuit, it is sent to the control IC.

[0007] The external printing host of this utility model is provided with a printing data output circuit. The output terminal of the printing data output circuit is connected to the signal input terminal of the encryption circuit, so that the printing data is sent out after encryption. Similar to the prior art, the external printing host provides a clock signal for the entire device. That is, the clock circuit of the external printing host is connected to the decryption circuit and the control IC in the thermal print head.

[0008] The decryption circuit described in this invention uses the VDD signal from the thermal printhead as its power source, and the GND terminal is connected to the GND terminal in the thermal printhead to save wiring space.

[0009] The shift register in the decryption circuit of this utility model is an 8-bit shift register, which can be a CD4014BCM. It has both parallel and serial input modes, and the mode switching is achieved through the P / S pin. It has three output ports: Q6, Q7, and Q8. Q6, Q7, and Q8 correspond to pins 2, 12, and 3, respectively. Q8 is connected to an external printer host. One of the three output ports is connected to pin 1 of the XOR logic chip. The XOR logic chip is an SN74AHC1G86DBVR. Pin 9 of the 8-bit shift register is connected to the PARALLEL / SERIAL port of the external printer via a socket. Pin 11 is connected to pin 2 of the XOR logic chip and also to the DATA port of the external printer via a socket. Pin 16 is connected to VDD, pin 8 is connected to GND, pin 10 (CLK) is connected to the CLK signal sent by the external printer, pin 5 of the XOR logic chip is connected to VDD, pin 4 is connected to the D1 terminal of the control IC, and pin 3 (GND) is grounded.

[0010] The one-time key storage circuit described in this utility model is implemented using an OTP chip or a pull-up resistor circuit. When a pull-up resistor circuit is used, the one-time key storage circuit has eight resistors connected to pins P1 to P8 of an 8-bit shift register. The connection method of the pull-up resistors corresponds to the key. For example, the other end of the resistors corresponding to pins P1, P3, P5, P6, and P8 of the 8-bit shift register is connected to VDD, and the other end of the resistors corresponding to pins P2, P4, and P7 of the 8-bit shift register is grounded, thereby completing the key preset.

[0011] The encryption circuit described in this invention includes an STM32F103ZET6 controller and peripheral circuitry. Pin 74 (PB13) of the STM32 controller outputs a clock signal to the decryption circuit, pin 76 (PB15) sends data to the decryption circuit, pin 75 (PB14) receives the key uploaded by the decryption circuit, and pin 73 (PB12) is connected to the P / S terminal of the 8-bit shift register in the decryption circuit to complete its operating mode switching. The controller is also connected to the control IC of the thermal printhead to send other drive signals. The peripheral circuitry includes crystal oscillators XTAL3, Y3, and XTA. L3 is connected between pins 8 and 9 of the controller. One end of capacitor C46 is grounded, and the other end is connected to both ends of crystal oscillator XTAL3. Crystal oscillator Y4 is connected between pins 23 and 24 of the controller. Resistor R22 is connected in parallel with crystal oscillator Y3. One end of capacitors C42 and C43 is grounded, and the other end is connected to both ends of resistor R22. Capacitor C40 is connected between the VDDA and VSSA pins of the controller. Capacitor C41 is connected in parallel with capacitor C40. One end of resistor R21 is connected to the VDDA pin of the controller, and the other end is connected to VCC. The VDD pin of the controller is connected to VCC, and the VSS pin of the controller is grounded.

[0012] The thermal printhead of this utility model includes a heat sink, a PCB circuit board, and a heating substrate for the thermal printhead. The bottom surface of the heating substrate for the thermal printhead is attached to the heat sink, and the upper surface of the heating substrate for the thermal printhead is provided with a heat storage glaze layer. A heating resistor and electrode wires are disposed on the upper surface of the heat storage glaze layer. The control IC on the PCB circuit board is connected to the pads at the ends of the electrode wires. The upper surfaces of the heating resistor and part of the electrode wires are covered with a protective layer, and the control IC and the pads are encapsulated with an encapsulating adhesive layer.

[0013] This invention incorporates an encryption circuit on an external printer host and a one-time key storage circuit and a decryption circuit on the thermal printhead. During printing, the decryption circuit first uploads a preset key from the one-time key storage circuit on the thermal printhead to the controller on the external printer host. Only after key verification is completed will the entire printing process begin; otherwise, printing will not start. Once printing begins, the print data is encrypted by the encryption circuit and then sent to the thermal printhead. The thermal printhead receives the data and processes it using a matching decryption circuit before the control IC drives the heating resistor for printing. This ensures accurate matching between the thermal printhead and the external printer host, guaranteeing print quality and equipment lifespan. The entire device has a reasonable structure, low cost, and low energy consumption, ensuring the overall lifespan and print quality of the equipment without affecting printing speed. Attached image description:

[0014] Appendix Figure 1 This is a circuit block diagram of this utility model.

[0015] Appendix Figure 2 This is a circuit schematic diagram of an embodiment of the present invention.

[0016] Appendix Figure 3 This is a schematic diagram of the structure of the thermal printhead in this utility model.

[0017] Appendix Figure 4 This is a schematic diagram of the cross-sectional structure of the thermal printhead in this utility model.

[0018] Figure reference numerals: 1. Heat sink plate; 2. Heating substrate; 3. Electrode wire; 4. Heating resistor; 5. Protective layer; 6. Control IC; 7. Encapsulating adhesive; 8. Encryption circuit; 9. Decryption circuit; 10. PCB board; 11. Signal socket; 12. Heat storage glaze layer; 13. One-time key storage circuit. Detailed implementation method:

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] This example provides a thermal printing device with encryption functionality, comprising an external printing host and a thermal printhead. The external printing host is connected to a control IC6 on the thermal printhead via a cable to enable power supply and transmission of printing data. The external printing host and the thermal printhead also have corresponding encryption circuits 8 and decryption circuits 9. The decryption circuit 8 is mounted on the PCB board 10 of the thermal printhead, and its output is connected to the control IC6. The decryption circuit 9 includes a one-time key storage circuit 13, a shift register, and an XOR logic chip. The one-time key storage circuit 13 is connected to the shift register, the shift register is connected to the XOR logic chip, and the output of the XOR logic chip is connected to the control IC6. The PCB board 10 of the thermal printhead has a signal socket 11 connected to the signal input terminal of the shift register. The output of the encryption circuit 8 is fed into the decryption circuit 9 via the signal socket 11, and after processing by the decryption circuit 9, it is sent to the control IC6.

[0021] The external printer host described in this example is equipped with a print data output circuit. The output terminal of the print data output circuit is connected to the signal input terminal of the encryption circuit 8, so that the print data is sent out after encryption. Similar to the prior art, the external printer host provides a clock signal for the entire device. That is, the clock circuit of the external printer host is connected to the decryption circuit 9 and the control IC6 in the thermal print head.

[0022] The power supply for the decryption circuit 9 described in this example uses the VDD signal from the thermal printhead, and the GND terminal is connected to the GND terminal in the thermal printhead to save wiring space.

[0023] As attached Figure 1 and appendix Figure 2As shown, the shift register in the decryption circuit is an 8-bit shift register, which can be a CD4014BCM. It has two input modes: parallel and serial. The mode switching is achieved through the P / S pin. It has three output ports: Q6, Q7, and Q8. Q6, Q7, and Q8 correspond to pins 2, 12, and 3, respectively. Q8 is connected to the external printer host. One of the three output ports is connected to pin 1 of the XOR logic chip. The XOR logic chip is an SN74AHC1G86DBVR. Pin 9 of the 8-bit shift register is connected to the PARALLEL / SERIAL port of the external printer via a socket. Pin 11 is connected to pin 2 of the XOR logic chip and also to the DATA port of the external printer via a socket. Pin 16 is connected to VDD, pin 8 is connected to GND, pin (10)CLK is connected to the CLK signal sent by the external printer, pin 5 of the XOR logic chip is connected to VDD, pin 4 is connected to the D1 terminal of the control IC, and pin GND is grounded.

[0024] The one-time key storage circuit 13 described in this example is implemented using a pull-up resistor circuit, as shown in the attached diagram. Figure 2 As shown, the one-time key storage circuit 13 has eight resistors connected to pins P1 to P8 of the 8-bit shift register. The connection method of the pull-up resistors corresponds to the key. For example, the other end of the resistors corresponding to pins P1, P3, P5, P6, and P8 of the 8-bit shift register is connected to VDD, and the other end of the resistors corresponding to pins P2, P4, and P7 of the 8-bit shift register is grounded, thereby completing the key preset.

[0025] As attached Figure 2 As shown, the encryption circuit 8 includes a controller STM32F103ZET6 and peripheral circuits. Pin 74 (PB13) of the STM32 controller outputs a clock signal to the decryption circuit, pin 76 (PB15) sends data to the decryption circuit, pin 75 (PB14) receives the key uploaded by the decryption circuit, and pin 73 (PB12) is connected to the P / S terminal of the 8-bit shift register in the decryption circuit 9 to complete its operating mode switching. The controller is also connected to the control IC of the thermal printhead to send other drive signals. The peripheral circuits include crystal oscillators XTAL3, Y3, and XTA. L3 is connected between pins 8 and 9 of the controller. One end of capacitor C46 is grounded, and the other end is connected to both ends of crystal oscillator XTAL3. Crystal oscillator Y4 is connected between pins 23 and 24 of the controller. Resistor R22 is connected in parallel with crystal oscillator Y3. One end of capacitors C42 and C43 is grounded, and the other end is connected to both ends of resistor R22. Capacitor C40 is connected between the VDDA and VSSA pins of the controller. Capacitor C41 is connected in parallel with capacitor C40. One end of resistor R21 is connected to the VDDA pin of the controller, and the other end is connected to VCC. The VDD pin of the controller is connected to VCC, and the VSS pin of the controller is grounded.

[0026] As attached Figure 1 As shown, the thermal printhead in this example includes a heat sink 1, a PCB circuit board 10, and a heating substrate for the thermal printhead. The bottom surface of the heating substrate for the thermal printhead is attached to the heat sink 10. The upper surface of the heating substrate for the thermal printhead is provided with a heat storage glaze layer 12. The upper surface of the heat storage glaze layer 12 is provided with a heating resistor 4 and an electrode wire 3. The control IC on the PCB circuit board 10 is connected to the pad at the end of the electrode wire. The upper surface of the heating resistor 4 and part of the electrode wire 3 is covered with a protective layer 5. The control IC 6 and the area around the pad are encapsulated with an encapsulating adhesive layer 7.

[0027] This example demonstrates how to install an encryption circuit on an external printer host and a one-time key storage circuit and decryption circuit on the thermal printhead. During printing, the decryption circuit first uploads the preset key from the one-time key storage circuit on the thermal printhead to the controller on the external printer host. Only after key verification is completed will the entire printing device be activated; otherwise, printing will not begin. Once printing is started, the print data is encrypted by the encryption circuit and then sent. The thermal printhead receives the data and processes it using a matching decryption circuit before the control IC drives the heating resistor for printing. This ensures accurate matching between the thermal printhead and the external printer host, guaranteeing print quality and equipment lifespan. The entire device has a reasonable structure, low cost, and low energy consumption, providing a highly stable thermal printing device without affecting printing speed.

Claims

1. A thermal printing device equipped with encryption function, comprising an external printing host and a thermal printhead, wherein, An external printer host is connected to a control IC on a thermal printhead via a cable to enable power supply and transmission of printing data. The external printer host and the thermal printhead are characterized by corresponding encryption and decryption circuits. The decryption circuit is mounted on the PCB of the thermal printhead, and its output is connected to the control IC. The decryption circuit includes a one-time key storage circuit, a shift register, and an XOR logic chip. The one-time key storage circuit is connected to the shift register, the shift register is connected to the XOR logic chip, and the output of the XOR logic chip is connected to the control IC. The PCB of the thermal printhead has a signal socket connected to the signal input of the shift register. The output of the encryption circuit is fed into the decryption circuit via the signal socket and processed by the decryption circuit before being sent to the control IC.

2. The thermal printing device with encryption function according to claim 1, characterized in that, The decryption circuit is powered by the VDD signal from the thermal printhead, and the GND terminal is connected to the GND terminal in the thermal printhead.

3. The thermal printing device with encryption function according to claim 1, characterized in that, The shift register in the decryption circuit is an 8-bit shift register, which can be a CD4014BCM. It has both parallel and serial input modes, and the mode switching is achieved through the P / S pin. It has three output ports: Q6, Q7, and Q8. Q6, Q7, and Q8 correspond to pins 2, 12, and 3, respectively. Q8 is connected to the external printer host. One of the three output ports is connected to pin 1 of the XOR logic chip. The XOR logic chip is an SN74AHC1G86DBVR. Pin 9 of the 8-bit shift register is connected to the PARALLEL / SERIAL port of the external printer via a socket. Pin 11 is connected to pin 2 of the XOR logic chip and also to the DATA port of the external printer via a socket. Pin 16 is connected to VDD, pin 8 is connected to GND, pin 10 is connected to the CLK signal sent by the external printer, pin 5 of the XOR logic chip is connected to VDD, pin 4 is connected to the D1 terminal of the control IC, and pin GND is grounded.

4. The thermal printing device with encryption function according to claim 3, characterized in that, The one-time key storage circuit is implemented using an OTP chip or a pull-up resistor circuit. When a pull-up resistor circuit is used, the one-time key storage circuit has eight resistors connected to pins P1 to P8 of an 8-bit shift register, and the connection method of the pull-up resistors corresponds to the key.

5. The thermal printing device with encryption function according to claim 3, characterized in that, The encryption circuit includes an STM32F103ZET6 controller and peripheral circuits. Pin 74 of the STM32 controller outputs a clock signal to the decryption circuit, pin 76 sends data to the decryption circuit, pin 75 receives the key uploaded by the decryption circuit, and pin 73 is connected to the P / S terminal of the 8-bit shift register in the decryption circuit to complete its working mode switching. The controller is also connected to the control IC of the thermal printhead to send drive signals.

6. The thermal printing device with encryption function according to claim 5, characterized in that, The peripheral circuit includes crystal oscillator XTAL3 and crystal oscillator Y3. Crystal oscillator XTAL3 is connected between pins 8 and 9 of the controller. One end of capacitor C46 is grounded, and the other end is connected to both ends of crystal oscillator XTAL3. Crystal oscillator Y4 is connected between pins 23 and 24 of the controller. Resistor R22 is connected in parallel with crystal oscillator Y3. One end of capacitors C42 and C43 is grounded, and the other end is connected to both ends of resistor R22. Capacitor C40 is connected between the VDDA and VSSA pins of the controller. Capacitor C41 is connected in parallel with capacitor C40. One end of resistor R21 is connected to the VDDA pin of the controller, and the other end is connected to VCC. The VDD pin of the controller is connected to VCC, and the VSS pin of the controller is grounded.

7. The thermal printing device with encryption function according to claim 1, characterized in that, The thermal printhead includes a heat sink, a PCB circuit board, and a heating substrate for the thermal printhead. The bottom surface of the heating substrate is attached to the heat sink, and the upper surface of the heating substrate is provided with a heat storage glaze layer. A heating resistor and electrode wires are disposed on the upper surface of the heat storage glaze layer. The control IC on the PCB circuit board is connected to the pads at the ends of the electrode wires. The upper surfaces of the heating resistor and part of the electrode wires are covered with a protective layer, and the control IC and the pads are encapsulated with an encapsulating adhesive layer.

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