Light-intensity-adjustable photoelectric detection circuit and label gap identification automatic detection equipment

Abstract

The utility model relates to the technical field of automatic detection equipment, in particular to a light-intensity-adjustable photoelectric detection circuit and label gap identification automatic detection equipment. A photoelectric detection circuit with adjustable light intensity is used for detecting a label gap. The circuit comprises a photoelectric emission circuit, a photoelectric receiving circuit, a PWM control circuit and a processor. The photoelectric emission circuit controls the current of a photoelectric emission tube through a PWM signal and adjusts the luminous intensity so as to adapt to labels of different colors and materials. The photoelectric receiving circuit receives an optical signal reflected by the label through a photoelectric transistor and converts the optical signal into a voltage signal, and the voltage signal is converted into a digital signal through an ADC to be processed by a processor. By dynamically adjusting the luminous intensity, the identification precision of labels with low contrast can be improved, misjudgment of interference patterns is avoided, and the photoelectric emission circuit can be closed when detection is not needed, so that energy conservation is realized. The scheme has the advantages of high flexibility and energy conservation, and is suitable for various automatic label detection systems.

Description

Technical Field

[0001] The utility model relates to the technical field of automated detection equipment, in particular to a photoelectric detection circuit with adjustable light intensity and automated detection equipment for identifying label gaps. Background Art

[0002] Existing label gap recognition systems primarily rely on photoelectric sensors, typically controlling the light intensity of a phototransistor through a fixed resistor. However, due to variations in label material, color, and reflectivity, fixed-intensity designs can lead to misjudgments or inaccurate detection when identifying certain low-contrast labels. Furthermore, patterns on labels can interfere with the system, causing misidentification. Existing technologies struggle to flexibly adapt to the characteristics of different label consumables, resulting in insufficient reliability and stability.

[0003] Therefore, how to develop a new solution to overcome the above shortcomings has become a topic to be studied by those skilled in the art. Utility Model Content

[0004] The purpose of the utility model is to provide a photoelectric detection circuit with adjustable light intensity and an automatic detection device for identifying label gaps in order to improve the applicability of label gap identification and detection in order to address the deficiencies of the existing technology.

[0005] The utility model achieves the above-mentioned purpose through the following technical solutions: a photoelectric detection circuit with adjustable light intensity, comprising:

[0006] A photoelectric emission circuit, the photoelectric emission circuit includes a photoelectric emission tube D1 and a first current-limiting resistor R1 connected in series with the photoelectric emission tube D1, and the photoelectric emission tube D1 is used to emit a light signal to the tag;

[0007] A photoelectric receiving circuit is used to receive the light signal reflected by the tag and convert it into a voltage signal;

[0008] A PWM control circuit, the PWM control circuit is used to adjust the current flowing through the photoelectric emission circuit to change the luminous intensity of the photoelectric emission tube D1; and

[0009] The processor is used to collect the voltage signal of the photoelectric receiving circuit to identify the gap position of the tag and adjust the duty cycle of the PWM control circuit to adjust the luminous intensity of the photoelectric transmitting circuit.

[0010] As a further solution of the present invention: the photoelectric emission circuit further includes a first control element, which is used to receive a PWM signal output by the PWM control circuit to control the current conduction and cutoff of the photoelectric emission tube D1.

[0011] As a further solution of the present utility model: the PWM control circuit includes a first resistor R2 and a base resistor R3;

[0012] The first control element is a transistor D2, the collector of the transistor D2 is connected to the cathode of the photoelectric emission tube D1, the base of the transistor D2 is connected to one end of the first resistor R2 and one end of the base resistor R3 respectively, the emitter of the transistor D2 is grounded, and the other end of the base resistor R3 is grounded;

[0013] The anode of the photoelectric emitting tube D1 is connected to one end of the first current limiting resistor R1 , and the other end of the first current limiting resistor R1 is connected to the power supply end.

[0014] As a further solution of the present utility model: the photoelectric receiving circuit includes a second current limiting resistor R5, a second resistor R4, a photoelectric receiving tube D3 and a digital-to-analog converter ADC, the collector of the photoelectric receiving tube D3 is respectively connected to one end of the second current limiting resistor R5 and one end of the second resistor R4, the emitter of the photoelectric receiving tube D3 is grounded, the other end of the second current limiting resistor R5 is connected to the power supply end, and the other end of the second resistor R4 is connected to the input end of the digital-to-analog converter ADC.

[0015] As a further solution of the present invention: the output end of the digital-to-analog converter ADC is connected to the processor.

[0016] Working Principle: A PWM signal controls the operating state of phototransistor D1. Adjusting the PWM duty cycle changes the current flowing through phototransistor D1, thereby adjusting its luminous intensity. Specifically, the PWM signal controls the current in phototransistor D1 by controlling the conduction state of transistor D2. When the PWM duty cycle is 50%, the average current in phototransistor D1 is I = 0.5 (VCC - Vd1) / R1.

[0017] When the contrast of the reflected light between labels is low, the processor increases the duty cycle of the PWM signal, boosting the luminous intensity of phototransmitter D1. This strengthens the signal received by photoreceiver D3, enabling accurate identification of label gaps. When interference patterns are present on the label, the processor reduces the duty cycle of the PWM signal, reducing the luminous intensity and preventing misoperation. Furthermore, when gap identification is not required, the PWM signal turns off phototransmitter D1, saving energy.

[0018] The present utility model also provides another technical solution: an automatic detection device for identifying label gaps, comprising a photoelectric detection circuit with adjustable light intensity as described in any one of the above.

[0019] Beneficial effects of the utility model:

[0020] This solution uses a PWM control circuit to adjust the current of phototransistor D1, adjusting the luminous intensity based on the intensity of the label's reflected light, adapting to label consumables of different colors and materials. When detecting low-contrast labels, the luminous intensity is increased; when interference patterns are present, the luminous intensity is reduced to avoid false positives. By disabling the phototransmitter circuit, energy savings are achieved, effectively improving the applicability of label gap detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a circuit diagram of related technology or conventional technology.

[0022] Figure 2 This is a schematic circuit diagram of the photoelectric detection circuit with adjustable light intensity described in the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It is understood that the drawings are only provided for reference and illustration purposes and are not intended to limit the present invention. The connection relationship shown in the drawings is only for the convenience of clear description and does not limit the connection method.

[0024] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the devices or components referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting the present invention. The terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, unless otherwise expressly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or it can be internal communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0026] In related technologies, such as Figure 1 The figure shows a conventional circuit diagram. A fixed current-limiting resistor, R1, is added to the phototransmitter D1. The current flowing through D1, I = (VCC - Vd1) / R1, is also fixed, and the luminous intensity is also fixed. The emitted light beam is reflected by the label consumable and enters the photoreceiver D2, causing it to enter the amplification region and conduct. Current flows through resistor R2, generating a voltage drop, VD1 = VDD - Id2 * R2. VD1 generates a pulse waveform as the label moves. The CPU's ADC detects the changing amplitude of VD1 to determine the position of the consumable gap. When the pulse width and amplitude exceed the threshold, a gap between labels is detected.

[0027] However, when the contrast of the reflected light between labels is low, the gap between labels cannot be accurately detected. Or, when the gap detection threshold is set too low, it is easy to misoperate, mistaking the normal position for the label gap. The fixed luminous intensity design cannot flexibly adapt to the various specifications and colors of label consumables.

[0028] To this end, embodiments of the present application provide a photoelectric detection circuit with adjustable light intensity and an automated detection device for label gap identification, aiming to improve the applicability of label gap identification and detection.

[0029] like Figure 2 As shown, in an embodiment of the present invention, a photoelectric detection circuit with adjustable light intensity is provided, comprising: a photoelectric transmitting circuit, a photoelectric receiving circuit, a PWM control circuit and a processor, wherein:

[0030] The photoelectric emission circuit includes a photoelectric emission tube D1 and a first current-limiting resistor R1 connected in series with the photoelectric emission tube D1, and the photoelectric emission tube D1 is used to emit a light signal to the tag;

[0031] The photoelectric receiving circuit is used to receive the light signal reflected by the tag and convert it into a voltage signal;

[0032] The PWM control circuit is used to adjust the current flowing through the photoelectric emission circuit to change the luminous intensity of the photoelectric emission tube D1;

[0033] The processor is used to collect the voltage signal of the photoelectric receiving circuit to identify the gap position of the tag and adjust the duty cycle of the PWM control circuit to adjust the luminous intensity of the photoelectric transmitting circuit.

[0034] The processor can automatically adjust the luminous intensity of the photoelectric emitting tube D1 according to the reflective intensity of different labels to ensure accurate recognition of the label gaps.

[0035] The PWM control circuit can automatically adjust the luminous intensity according to the different label materials, colors and patterns to avoid misoperation.

[0036] The processor can turn off the photoelectric emission circuit when there is no need to identify the tag gap, so as to save power.

[0037] Figure 2 The circuit design shown uses a PWM signal to control the operating state of phototransistor D1. Adjusting the PWM duty cycle changes the current flowing through phototransistor D1, thereby adjusting its luminous intensity. Specifically, the PWM signal controls the current in phototransistor D1 by controlling the conduction state of transistor D2. When the PWM duty cycle is 50%, the average current in phototransistor D1 is I = 0.5 (VCC - Vd1) / R1.

[0038] When the contrast of the reflected light between labels is low, the processor increases the duty cycle of the PWM signal, boosting the luminous intensity of phototransmitter D1. This strengthens the signal received by photoreceiver D3, enabling accurate identification of label gaps. When interference patterns are present on the label, the processor reduces the duty cycle of the PWM signal, reducing the luminous intensity and preventing misoperation. Furthermore, when gap identification is not required, the PWM signal turns off phototransmitter D1, saving energy.

[0039] In detail, this plan:

[0040] By regulating the current in phototransistor D1 through a PWM control circuit, the luminous intensity can be adjusted based on the intensity of the label's reflected light, adapting to label consumables of different colors and materials. A PWM signal (pulse-width modulation) is the core control method. The PWM signal controls the current in phototransistor D1 (LED) by varying its duty cycle (the proportion of time the signal is in the "high" state). Specifically, the PWM signal turns transistor D2 on and off. Phototransistors D1 and D2 form the phototransmitter circuit. The base of transistor D2 is controlled by the PWM signal. When the PWM signal is high, transistor D2 conducts, allowing current to flow through phototransistor D1, causing it to emit light. When the PWM signal is low, transistor D2 turns off, turning off phototransistor D1. The duty cycle determines the brightness of phototransistor D1: By adjusting the PWM duty cycle, the operating time of phototransistor D1 can be controlled. A higher duty cycle results in a longer light-on time and a higher light intensity; conversely, a lower duty cycle results in a lower light intensity. Adapting to the reflective properties of different labels: Labels vary in their ability to reflect light, depending on their material and color. Light-colored, smooth labels typically reflect more light, while dark, rough labels reflect less. By adjusting the PWM duty cycle, the luminous intensity can be adapted to different label materials, allowing the receiver to better detect the reflected light signal.

[0041] When detecting a label with low contrast, the luminous intensity can be increased; when an interference pattern is present, the luminous intensity can be reduced to avoid false positives. When using a photoelectric sensor to detect inter-label gaps, the reflective contrast between labels is a critical factor. If the labels have low contrast (for example, light-colored labels or materials with low reflectivity), the received photoelectric signal may not be strong enough, making it difficult to accurately detect the gap. In this case, increasing the PWM duty cycle can increase the luminous intensity of phototransistor D1, thereby enhancing the signal strength received by the photoelectric receiving circuit. Specifically, when the processor receives a signal from the ADC indicating insufficient received light intensity, it can increase the PWM duty cycle, increasing the current flowing through phototransistor D1 to boost the luminous intensity. This way, even with weak reflective labels, the photoelectric receiving circuit can receive sufficient light to detect inter-label gaps. When interfering patterns are present, if a label has a pattern that could be mistaken for a gap, the reflected light signal will be strong, making it prone to false positives. The processor can reduce the PWM duty cycle to reduce the luminous intensity, thereby reducing the received signal strength and filtering out the interference signal. This dynamic adjustment can ensure that in complex labeling situations, it can adapt to different situations and improve the accuracy of label gap recognition.

[0042] Energy saving can be achieved by turning off the photoelectric emission circuit. This effectively improves the applicability of tag gap identification detection. To further optimize energy efficiency, this solution allows on-demand control of the photoelectric emission circuit, turning off the circuit when detection is not required. Specifically, the PWM signal turns off the emission tube: when the processor determines that tag detection is not required within a certain period of time, it can turn off the conduction of transistor D2 by setting the PWM signal to "low level", thereby turning off the photoelectric emission tube D1. No current flows through the photoelectric emission tube D1: when the photoelectric emission tube D1 is turned off, no current flows in the entire photoelectric emission circuit, thereby achieving energy saving. This can significantly reduce the power consumption of the circuit when continuous operation is required for a long time.

[0043] In one embodiment, the photoelectric emission circuit further includes a first control element, which is configured to receive a PWM signal output by the PWM control circuit to control the current conduction and cutoff of the photoelectric emission tube D1.

[0044] In another embodiment, the PWM control circuit includes a first resistor R2 and a base resistor R3;

[0045] The first control element is a transistor D2, the collector of the transistor D2 is connected to the cathode of the photoelectric emission tube D1, the base of the transistor D2 is connected to one end of the first resistor R2 and one end of the base resistor R3 respectively, the emitter of the transistor D2 is grounded, and the other end of the base resistor R3 is grounded;

[0046] The anode of phototransistor D1 is connected to one end of a first current-limiting resistor R1, the other end of which is connected to a power supply. Specifically, the processor model can use two main control chips, such as the MH1903S and / or MH2101 (the main control CPUs of both products). The processor's hardware PWM interface controls the output to the PWM control circuit. First resistor R2 is directly coupled to the PWM control circuit, with the IO port where the PWM control circuit resides directly connected to the first resistor R2 (current-limiting resistor).

[0047] In another embodiment, the photoelectric receiving circuit includes a second current-limiting resistor R5, a second resistor R4, a photoelectric receiving tube D3, and a digital-to-analog converter (ADC). The collector of the photoelectric receiving tube D3 is connected to one end of the second current-limiting resistor R5 and one end of the second resistor R4, respectively. The emitter of the photoelectric receiving tube D3 is grounded. The other end of the second current-limiting resistor R5 is connected to a power supply, and the other end of the second resistor R4 is connected to the input of the digital-to-analog converter (ADC). Specifically, the photoelectric receiving tube D3 is a phototransistor, the base of which is controlled by incident light. When photons strike the phototransistor, a base current is generated, causing the current between the collector and emitter to increase. The photoelectric receiving tube D3 receives the light signal reflected from the tag, generating a current proportional to the light intensity. This current flows through the load resistor, namely the second current-limiting resistor R5, to generate a voltage signal in the circuit. This signal is fed into the ADC for digitization, which is used by the processor to determine whether a tag gap exists.

[0048] In yet another embodiment, an output terminal of the digital-to-analog converter ADC is connected to the processor.

[0049] An automatic detection device for identifying label gaps comprises a photoelectric detection circuit with adjustable light intensity as described in any one of the above.

[0050] like Figure 2 As shown, a PWM signal is used to control the switching of transistor D2, thereby controlling the on / off switching of phototransistor D1. Adjusting the PWM duty cycle can set the current flowing through the first current-limiting resistor R1, thereby adjusting the light intensity of phototransistor D1. For example, when the PWM duty cycle is set to 50%, the average current flowing through phototransistor D1 is I = 0.5 (VCC - Vd1) / R1.

[0051] When the contrast of the collected tag gap value is too small, the current of the photoelectric transmitting tube D1 can be increased by increasing the PWM duty cycle, thereby increasing the luminous intensity. The signal strength received by the photoelectric receiving tube D3 also increases, and when it reaches above the detection threshold, the gap position of the tag can be collected and identified.

[0052] When there is a specific pattern on the collected label, it is easy to be mistaken for a label gap and the light intensity needs to be reduced. The duty cycle of the PWM output can be lowered to reduce the luminous intensity of the photoelectric emission tube D1 to filter out the interference signal.

[0053] In the description and claims of this application, the words "include / comprise" and the words "have / include" and their variations are used to specify the existence of stated features, values, steps or components, but do not exclude the existence or addition of one or more other features, values, steps, components or their combinations.

[0054] Some features of the present invention are described in separate embodiments for clarity of explanation, however, these features may also be described in combination in a single embodiment. Conversely, some features of the present invention are described in a single embodiment for brevity, however, these features may also be described in different embodiments individually or in any suitable combination.

[0055] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A photoelectric detection circuit with adjustable light intensity, characterized in that: include: A photoelectric emission circuit, the photoelectric emission circuit includes a photoelectric emission tube D1 and a first current-limiting resistor R1 connected in series with the photoelectric emission tube D1, and the photoelectric emission tube D1 is used to emit a light signal to the tag; A photoelectric receiving circuit is used to receive the light signal reflected by the tag and convert it into a voltage signal; PWM control circuit, the PWM control circuit is used to adjust the current flowing through the photoelectric emission circuit to change the luminous intensity of the photoelectric emission tube D1; as well as The processor is used to collect the voltage signal of the photoelectric receiving circuit to identify the gap position of the tag and adjust the duty cycle of the PWM control circuit.

2. The light intensity adjustable photoelectric detection circuit according to claim 1, characterized in that: The photoelectric emission circuit further includes a first control element, which is used to receive a PWM signal output by the PWM control circuit to control the current conduction and cutoff of the photoelectric emission tube D1.

3. The light intensity adjustable photoelectric detection circuit according to claim 2, characterized in that: The PWM control circuit includes a first resistor R2 and a base resistor R3; The first control element is a transistor D2, the collector of the transistor D2 is connected to the cathode of the photoelectric emission tube D1, the base of the transistor D2 is connected to one end of the first resistor R2 and one end of the base resistor R3 respectively, the emitter of the transistor D2 is grounded, and the other end of the base resistor R3 is grounded; The anode of the photoelectric emitting tube D1 is connected to one end of the first current limiting resistor R1 , and the other end of the first current limiting resistor R1 is connected to the power supply end.

4. The light intensity adjustable photoelectric detection circuit according to claim 3, characterized in that: The photoelectric receiving circuit includes a second current-limiting resistor R5, a second resistor R4, a photoelectric receiving tube D3 and a digital-to-analog converter ADC. The collector of the photoelectric receiving tube D3 is connected to one end of the second current-limiting resistor R5 and one end of the second resistor R4 respectively. The emitter of the photoelectric receiving tube D3 is grounded. The other end of the second current-limiting resistor R5 is connected to the power supply end, and the other end of the second resistor R4 is connected to the input end of the digital-to-analog converter ADC.

5. The light intensity adjustable photoelectric detection circuit according to claim 4, characterized in that: The output end of the digital-to-analog converter ADC is connected to the processor.

6. A label gap recognition automated detection device, characterized in that: The invention comprises a photoelectric detection circuit with adjustable light intensity as claimed in any one of claims 1 to 5.

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