Laser control circuit of code scanning device

Abstract

The utility model relates to circuit technical field especially, and more particularly to a kind of laser control circuit of code scanning equipment, comprising: total power supply connection end, rear power supply connection end, CPU connection end, camera module connection end, power switch module, laser control module, laser module;Wherein, the total power supply connection end is connected with power switch module, laser control module respectively, the rear power supply connection end is connected with power switch module, laser module respectively, the camera module connection end is connected with power switch module, laser control module respectively, the CPU connection end is connected with power switch module, laser control module respectively, the power switch module is also connected with laser control module, laser module respectively.By the logic control between JK latch and triode, it is realized that code scanning equipment measures distance when taking picture, and adjusts liquid lens posture, and control laser mark blanking when decoding, eliminates the interference of laser mark to decoding process.

Description

Technical Field

[0001] This utility model relates to the field of circuit technology, and in particular to a laser control circuit for a barcode scanning device. Background Technology

[0002] Most barcode scanners on the market today use fixed-focus scanning engines, suitable for scenarios where the user is close to the object. During image exposure, the laser mark used for aiming and other functions of the scanner is hidden. However, with the continuous expansion of the application scenarios of barcode scanners and the upgrading of scanning technology, zoom lenses, also known as liquid lenses, have gradually emerged. The dynamic focusing of liquid lenses requires the laser to be turned on during the camera exposure. The object distance is calculated in real time by the spot offset to drive the liquid lens to focus. Therefore, there is an urgent need for a circuit that can dynamically control the appearance of the laser mark on the object surface during image exposure, assist in measuring the distance and adjusting the liquid lens to a suitable decoding angle, and then turn off the laser mark before decoding. Utility Model Content

[0003] This invention provides a laser control circuit for a barcode scanner, which solves the problem that the liquid lens of the existing barcode scanner cannot achieve step-by-step control of laser mark ranging and decoding, resulting in low decoding efficiency. The circuit realizes the logic control that the laser mark assists in ranging during image exposure and is in a blanking state during decoding, thereby improving decoding efficiency.

[0004] This utility model provides a laser control circuit for a barcode scanning device, including: a main power connection terminal, a secondary power connection terminal, a CPU connection terminal, a camera module connection terminal, a power switch module, a laser control module, and a laser module;

[0005] The main power supply connection is connected to the power switch module and the laser control module, the downstream power supply connection is connected to the power switch module and the laser module, the camera module connection is connected to the power switch module and the laser control module, the CPU connection is connected to the power switch module and the laser control module, and the power switch module is also connected to the laser control module and the laser module.

[0006] According to the laser control circuit of the barcode scanning device provided by this utility model, the power switch module includes a first dual transistor, whose first pin is connected to the main power supply terminal, the second pin is connected to the CPU terminal, the third pin is connected to the laser module, the fourth pin is grounded, the fifth pin is connected to the camera module terminal through the first resistor, and the sixth resistor is connected to the subsequent power supply terminal.

[0007] According to the laser control circuit of the barcode scanning device provided by this utility model, the first pin of the first dual transistor is also grounded through the first capacitor, and the fifth pin is also connected to the laser control module.

[0008] According to the present invention, a laser control circuit for a barcode scanning device is provided, wherein the laser module comprises a second dual triode and a laser tube;

[0009] In this configuration, pin 1 of the second dual transistor is grounded, pin 2 is grounded through the sixth resistor, pin 3 is connected to pin 1 of the laser tube, pin 4 is grounded through the fifth resistor, pins 5 and 6 are both connected to the power supply terminal of the subsequent stage through the fourth resistor, and pins 5 and 6 of the second dual transistor are also connected to pin 3 of the first dual transistor.

[0010] According to the laser control circuit of the barcode scanning device provided by this utility model, the second pin of the laser tube is connected to the power supply terminal of the subsequent stage, and the third pin is connected to the line connecting the second pin of the second dual transistor and the sixth resistor.

[0011] According to the present invention, a laser control circuit for a barcode scanning device is provided, wherein the laser control module includes a transistor and a JK latch;

[0012] The JK latch has 16 pins. Its CLK pin is connected to the camera module connection terminal, 1K pin, 1J pin, and 1CLRn pin are connected to the CPU connection terminal respectively, 1PREn pin is connected to the main power supply connection terminal through a third resistor, VCC pin is connected to the main power supply connection terminal, GND pin is grounded, and 1Q pin is connected to the base of the transistor through a second resistor.

[0013] According to the laser control circuit of the barcode scanning device provided by this utility model, the VCC pin of the JK latch is also grounded through a second capacitor.

[0014] According to the laser control circuit of the barcode scanning device provided by this utility model, the collector of the transistor is connected to the fifth pin of the first dual transistor, and the emitter of the transistor is grounded.

[0015] The laser control circuit of the barcode scanning device provided by this utility model controls the laser tube to emit a laser mark during image exposure to measure the distance and drive the liquid lens to focus through the logic control between the JK latch and the transistor. After the distance calibration is completed, the laser mark is immediately controlled to disappear, eliminating the influence of the laser source on the image decoding process. This achieves the effect of step-by-step control of laser mark ranging and accurate decoding, with the two not interfering with each other. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is an electrical block diagram of the laser control circuit of the barcode scanning device provided by this utility model;

[0018] Figure 2 This is a circuit diagram of the laser control circuit of the barcode scanning device provided by this utility model;

[0019] Figure 3 This is the timing diagram of each pin of the JK latch. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] The following is combined Figures 1-3 The present invention describes a laser control circuit for a barcode scanning device, comprising: a main power supply connection terminal, a secondary power supply connection terminal, a CPU connection terminal, a camera module connection terminal, a power switch module, a laser control module, and a laser module;

[0022] The main power supply connection is connected to the power switch module and the laser control module, the secondary power supply connection is connected to the power switch module and the laser module, the camera module connection is connected to the power switch module and the laser control module, the CPU connection is connected to the power switch module and the laser control module, and the power switch module is also connected to the laser control module and the laser module.

[0023] Furthermore, the power switch module includes a first dual transistor D1, model BC847BVN, which is an electronic device composed of a PNP transistor and an NPN transistor packaged in the same housing and independent of each other. The first dual transistor D1 has six pins: pin 1 is connected to the main power supply terminal, pin 2 is connected to the CPU terminal, pin 3 is connected to the laser module, pin 4 is grounded, pin 5 is connected to the camera module terminal through the first resistor R1, and pin 6 is connected to the subsequent power supply terminal.

[0024] In this embodiment, when pin 2 of the first dual transistor D1 is at a high level, pins 1 and 2 of the first dual transistor D1 cannot form a pressure difference, and pins 1 and 6 are disconnected. At this time, the power supply cannot supply power to the device, and the device cannot work normally. When pin 2 of the first dual transistor D1 is at a low level, pins 1 and 2 of the first dual transistor D1 form a pressure difference, and pins 1 and 6 are connected. At this time, the power supply supplies power to the device, and the device can be turned on or off by the user.

[0025] Furthermore, the first pin of the first dual transistor D1 is grounded through the first capacitor C1, and the fifth pin is connected to the laser control module.

[0026] The laser module includes a second dual transistor D2 and a laser tube M1. The second dual transistor D2 is a BC847BV, which is an electronic device composed of two independent NPN transistors packaged in the same housing. The second dual transistor D2 has six pins. Its first pin is grounded, its second pin is grounded through the sixth resistor R6, its third pin is connected to the first pin of the laser tube M1, its fourth pin is grounded through the fifth resistor R5, and its fifth and sixth pins are both connected to the power supply terminal of the subsequent stage through the fourth resistor R4. The fifth and sixth pins of the second dual transistor D2 are also connected to the third pin of the first dual transistor D1.

[0027] Furthermore, pin 2 of laser tube M1 is connected to the power supply terminal of the subsequent stage, and pin 3 is connected to the line connecting pin 2 of the second dual transistor D2 and the sixth resistor R6.

[0028] In this embodiment, when pin 5 of the first dual transistor D1 is at a high level, a pressure difference is formed between pins 5 and 4 of the first dual transistor D1, and pins 3 and 4 are connected, so that pins 5 and 6 of the second dual transistor D2 are grounded through pins 3 and 4 of the first dual transistor D1, and the second dual transistor D2 is disconnected, thereby controlling the laser tube M1 to turn off (i.e., laser mark blanking); when pin 5 of the first dual transistor D1 is at a low level, a pressure difference cannot be formed between pins 5 and 4 of the first dual transistor D1, and pins 3 and 4 are disconnected. At this time, pins 5 and 6 of the second dual transistor D2 are at a high level through the pull-up effect of the fourth resistor R4, so that the second dual transistor D2 is connected, and the laser tube M1 is powered by the subsequent power supply. At this time, the laser tube M1 starts to work (i.e., the laser mark appears on the surface of the object to be identified).

[0029] The laser control module includes a transistor Q1 and a JK latch U1. The JK latch U1 has 16 pins: CLK, 1K, 1J, 1PREn, 1Q, 1Qn, 2Qn, GND, 2Q, 2PREn, 2J, 2K, 2CLK, 2CLRn, 1CLRn, and VCC. The CLK pin is connected to the camera module connection terminal, while the 1K, 1J, and 1CLRn pins are connected to the CPU connection terminal. The 1PREn pin is connected to the main power supply terminal via a third resistor R3, the VCC pin is also connected to the main power supply terminal, and the GND pin is grounded. The 1Q pin is connected to the base of the transistor Q1 via a second resistor R2. The 1Qn, 2Qn, 2Q, 2PREn, 2J, 2K, 2CLK, and 2CLRn pins of the JK latch U1 are all left floating.

[0030] Furthermore, the VCC pin of the JK latch U1 is also grounded through the second capacitor C2.

[0031] Furthermore, the collector of transistor Q1 is connected to pin 5 of the first dual transistor D1, and the emitter of transistor Q1 is grounded.

[0032] In a specific embodiment, pin 1Q of latch U1 serves as a signal output pin. The type of its output signal is determined by the states of pins 1K and 1J of latch U1, and is triggered by the falling edge of its CLK pin. According to the background description, in this invention, when a user needs to measure the optimal distance between the camera module and the object to be identified, the laser marker of laser tube M1 needs to be controlled to appear on the surface of the object to be identified. This assists the user in distance measurement and timely lens adjustment, ensuring the lens can clearly identify the object. Figure 3As shown, before scanning an object, the user controls the CPU to set pin 1K of JK latch U1 to a low level and pin 1J to a high level. Then, the camera module is controlled to start scanning the object. JK latch U1 is triggered on the first falling edge of its CLK pin, causing pin 1Q of JK latch U1 to be high, meaning the base of transistor Q1 is high. This creates a voltage difference between the base and emitter of transistor Q1, causing the collector and emitter of transistor Q1 to conduct. At this time, the first dual transistor D1... Pin 5 is grounded through the collector and emitter of transistor Q1. Pins 5 and 4 of dual transistor D1 cannot form a voltage difference, and pins 3 and 4 are disconnected. At this time, pins 5 and 6 of the second dual transistor D2 are at a high level through the pull-up effect of the fourth resistor R4, making the second dual transistor D2 internally conduct. The power supply of the subsequent stage supplies power to the laser tube M1, successfully controlling the laser mark of the laser tube M1 to appear on the surface of the object to be identified. The target distance is calculated based on the offset of the laser mark in the image, improving the decoding success rate.

[0033] In this embodiment, when the camera module is scanning an object, the laser module will assist the user in measuring the optimal scanning distance and adjusting the lens appropriately with constant power. When the current flowing through pin 3 of laser tube M1 increases, the current flowing through pin 1 of laser tube M1 decreases; conversely, when the current flowing through pin 3 of laser tube M1 decreases, the current flowing through pin 1 of laser tube M1 increases. This ensures that the laser module always operates at a constant power. The specific working principle is as follows:

[0034] The current at pin 3 of laser tube M1 changes with the overall light intensity of laser tube M1. For example, when the overall light intensity of laser tube M1 increases, the current flowing through its pin 3 also increases. This leads to an increase in the current flowing through the sixth resistor R6 and the second pin of the second dual transistor D2. A voltage difference is formed between pins 2 and 1 of the second dual transistor D2, causing pins 1 and 6 of the second dual transistor D2 to conduct. Due to the current shunting effect between pins 1 and 6 of the second dual transistor D2, the current flowing into pin 5 of the second dual transistor D2 decreases, ultimately reducing the current flowing through pin 1 of laser tube M1. Similarly, when the overall light intensity of laser tube M1 decreases, the current at its pin 3 also decreases, ultimately increasing the current flowing through pin 1 of laser tube M1, ensuring that the laser module always operates at a constant power.

[0035] When the user determines to decode at the current distance, the laser tube M1 can be turned off by controlling the output states of pins 1K and 1J of the JK latch U1 via the CPU. The specific principle is as follows: When the CPU controls pin 1K of the JK latch U1 to be high and pin 1J to be low, pin 1Q of the JK latch U1 changes from high to low. At this time, the base of transistor Q1 is low, and no voltage difference can be formed between it and the emitter of transistor Q1. Therefore, the collector of transistor Q1... When the emitter is disconnected, pin 5 of the first dual transistor D1 is at a high level, and a voltage difference is formed between pins 4 and 5 of the first dual transistor D1. Pins 3 and 4 of the first dual transistor D1 are turned on, causing pins 5 and 6 of the second dual transistor D2 to be grounded through pins 3 and 4 of the first dual transistor D1. This causes the second dual transistor D2 to be disconnected. At this time, the laser mark of the laser tube M1 disappears and no longer appears on the surface of the object to be identified. The square camera module captures a clear image.

[0036] On the other hand, the CPU can control the 1CLRn pin of JK latch U1 to change from a high level to a low level. At this time, the 1Q pin of JK latch U1 will directly and synchronously change to a low level, unaffected by the output state of other pins. This can also turn off the transistor Q1, thereby controlling the blanking of the laser mark of the laser tube M1.

[0037] If decoding at the current distance fails, the above operation can be repeated to make the laser mark of laser tube M1 appear on the surface of the object to be identified again, and then the distance and lens can be readjusted. After the adjustment is completed, the laser mark of laser tube M1 can be made to disappear until decoding is successful.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A laser control circuit for a barcode scanning device, characterized in that, include: Main power connector, power supply connector, CPU connector, camera module connector, power switch module, laser control module, laser module; The main power supply connection is connected to the power switch module and the laser control module, the downstream power supply connection is connected to the power switch module and the laser module, the camera module connection is connected to the power switch module and the laser control module, the CPU connection is connected to the power switch module and the laser control module, and the power switch module is also connected to the laser control module and the laser module.

2. The laser control circuit of the barcode scanning device according to claim 1, characterized in that, The power switch module includes a first dual transistor, whose first pin is connected to the main power supply terminal, the second pin is connected to the CPU terminal, the third pin is connected to the laser module, the fourth pin is grounded, the fifth pin is connected to the camera module terminal through a first resistor, and the sixth resistor is connected to the subsequent power supply terminal.

3. The laser control circuit of the barcode scanning device according to claim 2, characterized in that, The first pin of the first dual transistor is also grounded through the first capacitor, and the fifth pin is also connected to the laser control module.

4. The laser control circuit of the barcode scanning device according to claim 2, characterized in that, The laser module includes a second dual triode and a laser tube; In this configuration, pin 1 of the second dual transistor is grounded, pin 2 is grounded through the sixth resistor, pin 3 is connected to pin 1 of the laser tube, pin 4 is grounded through the fifth resistor, pins 5 and 6 are both connected to the power supply terminal of the subsequent stage through the fourth resistor, and pins 5 and 6 of the second dual transistor are also connected to pin 3 of the first dual transistor.

5. The laser control circuit of the barcode scanning device according to claim 4, characterized in that, The second pin of the laser tube is connected to the power supply terminal of the subsequent stage, and the third pin is connected to the line connecting the second pin of the second dual transistor and the sixth resistor.

6. The laser control circuit of the barcode scanning device according to claim 3, characterized in that, The laser control module includes a transistor and a JK latch; The JK latch has 16 pins. Its CLK pin is connected to the camera module connection terminal, 1K pin, 1J pin, and 1CLRn pin are connected to the CPU connection terminal respectively, 1PREn pin is connected to the main power supply connection terminal through a third resistor, VCC pin is connected to the main power supply connection terminal, GND pin is grounded, and 1Q pin is connected to the base of the transistor through a second resistor.

7. The laser control circuit of the barcode scanning device according to claim 6, characterized in that, The VCC pin of the JK latch is also grounded through a second capacitor.

8. The laser control circuit of the barcode scanning device according to claim 7, characterized in that, The collector of the transistor is connected to pin 5 of the first dual transistor, and the emitter of the transistor is grounded.

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