Current-limiting high-burst-flash lighting system and image recognition equipment

Abstract

The invention relates to a current-limiting high-flash illumination system and image recognition equipment. The current-limiting high-flash illumination system comprises a current-limiting module, a boosting module, an energy storage module, a constant-current module and an exposure flash control module. The exposure flash control module comprises a main control chip, a lighting assembly and an image sensor. By limiting the preceding-stage current, the stability of the preceding-stage circuit and the preceding-stage circuit is ensured, the constant current during the illumination period and the consistency of the illumination brightness of LEDs in different bin regions are ensured through the constant current module, the image sensor and illumination are controlled to be synchronously turned on and off, and short-time illumination and exposure synchronization is realized. The short-time efficient illumination exposure is realized, the illumination duration is shortened, and image smear is avoided.

Description

Technical Field

[0001] The present invention relates to the field of lighting control of image recognition, and in particular to a current-limited high-explosive flash lighting system and image recognition equipment. Background Art

[0002] Existing image recognition technology, especially barcode reading equipment, mostly uses low-current long-time exposure lighting to meet the exposure requirements of products. This lighting method is mainly used because the main application scenarios of code scanning, such as supermarkets, logistics, etc., mainly use USB or battery power supply, which limits the product's lighting brightness, affects the product's mobile adaptability performance, and cannot meet the growing demand for decoding mobile adaptability.

[0003] When the image sensor is collecting images, when the lighting brightness is low, in order to ensure that the image brightness meets the decoding requirements, it needs a longer exposure time; the traditional decoder is limited by the power supply capacity of the previous circuit, and often adopts a small current and long exposure solution, which leads to the problem of image smearing and blurring. This problem will cause serious smearing when the scanning object moves at a fast speed, increasing the difficulty of parsing the barcode image, and thus cannot meet the needs of high-mobility adaptability scenes; the illumination system of existing barcode scanners mostly adopts a constant voltage power supply solution, and controls the lighting current through a series resistor. Due to the difference in the rated operating voltage of the LED light-emitting tubes in different BIN areas, the working current of the lighting lamps of mass-produced products is different. The large difference makes the lighting performance and working current of different batches of the same product vary greatly, affecting the consistency of the product; in multi-lamp applications, existing barcode scanning products use multiple lamps in parallel to fill the light. Due to the differences in the BIN areas of LED lamps, the parallel connection method will cause differences in the working currents of different lamps in a group of LED lamps, further leading to uneven lighting problems; when the lighting of the product is turned on, the working current of the product will increase significantly, which puts forward greater requirements on the front-end load capacity of the host computer / PDA. On the other hand, due to the limitation of the circuit's current carrying capacity, when the working current is increased, the voltage drop caused by the parasitic resistance in the circuit will also increase, which will have an adverse effect on the normal operation of the lighting system and even the barcode scanning module. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a current-limited high-explosion flash lighting system and an image recognition device in view of the deficiencies of the above-mentioned prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A current-limited high-explosion flash lighting system, comprising:

[0007] A current limiting module, wherein the input end of the current limiting module is connected to a power supply, and the current limiting module outputs a current limiting current after detecting a current value of the power supply input and implementing feedback regulation;

[0008] A boost module, the input end of the boost module is connected to the output end of the current limiting module;

[0009] An energy storage module, the input end of the energy storage module is connected to the output end of the boost module;

[0010] A constant current module, the input end of which is connected to the output end of the energy storage module;

[0011] A flash control module, the flash control module is respectively connected to the boost module, the energy storage module and the constant current module;

[0012] Among them, the strobe control module is composed of a main control chip, a lighting component, and an image sensor. The main control chip is connected to the lighting component and the image sensor respectively, and controls the working status of the lighting component and the image sensor.

[0013] The energy storage module includes an aluminum electrolytic capacitor or a tantalum capacitor.

[0014] The energy storage module stores energy during non-lighting periods and outputs electrical energy during lighting periods.

[0015] The boost module performs a voltage boost process on the current-limiting current output by the current-limiting module to meet the working voltage of the lighting component.

[0016] The lighting component is composed of a plurality of LEDs connected in series, and the constant current module supplies power to the plurality of LEDs in series.

[0017] The power source is a USB power supply or a handheld terminal battery.

[0018] Solution 2

[0019] An image recognition device comprises a current-limited high-explosive flash lighting system as described in any one of the schemes.

[0020] The image recognition equipment includes a barcode reading equipment, an optical character reading equipment, and a machine vision equipment.

[0021] The advantages of the present invention are:

[0022] 1) The constant current module solves the problem of lighting performance differences between product lighting batches due to differences in LED consistency and lighting efficiency differences caused by differences in different LEDs in a single product.

[0023] 2) In a multi-lamp lighting system, when multiple lamps are connected in parallel or a constant voltage power supply solution is used, the difference in the bin area used for the lighting lamps leads to differences in the current of different LEDs under constant voltage conditions, which in turn leads to differences in brightness and uneven lighting. After adopting the boost power supply method, the parallel power supply can be changed to series power supply, which can ensure that the current passing through the LEDs on the same circuit is consistent, thereby improving the uniformity of lighting.

[0024] 3) By using the energy storage module, the LED current is guaranteed to be stable during constant current exposure after the voltage is raised, reducing the problem of insufficient energy caused by series high voltage and previous current limitation, and the decrease in lighting brightness during exposure.

[0025] 4) Introducing a current limiting module, through the combination of the current limiting module and the energy storage module, the amount of current that the rear stage of the lighting lamp instantly draws from the front stage is limited, reducing the demand for the power supply capacity of the front stage, making it better suitable for scenarios with limited instantaneous load capacity such as USB power supply and PDA battery power supply;

[0026] 5) The flash exposure module adopts a short-time, high-brightness exposure mode. It reduces the exposure time of the image while ensuring the brightness of the image through high brightness, thereby solving the inevitable ghosting problem in the sensor design process and improving the image quality, thereby increasing the decoding success rate of the decoding library and improving the mobile adaptability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A system block diagram of a current-limited high-explosion flash lighting system according to an embodiment of the present invention;

[0028] 1-current limiting module, 2-boosting module, 3-energy storage module, 4-constant current module, 5-strobe module, 51-main control chip, 52-lighting component, 53-image sensor. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 As shown:

[0031] A current-limited high-explosion flash lighting system, characterized by comprising:

[0032] The current limiting module 1 has an input end connected to a power supply, and the current limiting module 1 detects the current value of the power supply input, implements feedback regulation, and outputs a current limiting current. The current limiting module 1 is composed of a current limiting chip or an operational amplifier feedback circuit.

[0033] In this embodiment, the current limiting module 1 detects the input current through the current limiting chip or the operational amplifier feedback circuit. When it is detected that the instantaneous current exceeds the limit value, the current limiting module 1 limits the input current.

[0034] A boost module 2, the input end of which is connected to the output end of the current limiting module 1. The boost module 2 is composed of a boost circuit, which is a BOOST boost circuit composed of a boost chip and inductors and capacitors. The voltage passing through the current limiting module 1 is raised by the boost module 2 to a voltage that can power the lighting assembly 52.

[0035] Energy storage module 3, the input end of the energy storage module 3 is connected to the output end of the boost module 2. In this embodiment, the capacitance of the energy storage module is not less than 200uF.

[0036] The energy storage module 3 includes an aluminum electrolytic capacitor or a tantalum capacitor.

[0037] The energy storage module 3 stores energy during the non-lighting period and outputs electric energy during the lighting period, thereby ensuring that the voltage and current of the system are stable in the high current mode during the lighting period.

[0038] In this embodiment, the energy storage module 3 is passively adjusted according to the current conditions of the previous and next stages.

[0039] A constant current module 4, the input end of which is connected to the output end of the energy storage module 3, and the constant current module 4 is composed of an operational amplifier circuit or a constant current driver chip. The constant current module 4 is used to control the constant current output of the lighting, and is used to ensure that the LED lighting under different bin conditions is consistent. The energy during the lighting period of the constant current module 4 is provided by the energy storage module 3;

[0040] The flash control module 5 is connected to the boost module 2, the energy storage module 3 and the constant current module 4 respectively.

[0041] The flash control module 5 is composed of a main control chip 51, a lighting component 52, and an image sensor 53. The main control chip 51 is connected to the lighting component 52 and the image sensor 53 respectively, and controls the working states of the lighting component 52 and the image sensor 53.

[0042] The flash control module 5 is connected to the circuits of the boost module 2 and the constant current module 4 respectively through I2C or other communication circuits, and controls the on / off and parameter setting of the boost module 2 and the constant current module 4 by transmitting control signals. Specifically, the boost module 2 and the constant current module 4 are controlled by the main control chip 51.

[0043] During the flash exposure, the boost module 2, the energy storage module 3 and the constant current module 4 provide stable high current, high brightness, short time, and highly synchronized exposure lighting, so as to achieve short-time and efficient lighting exposure, shorten the lighting time and avoid image smear.

[0044] The lighting component 52 is connected to the constant current module 4 and receives energy during lighting.

[0045] The lighting assembly 52 is composed of a plurality of LEDs connected in series.

[0046] The power source is a USB power supply or a handheld terminal battery.

[0047] In this embodiment, under the same barcode test conditions using Code128 14.63mil, the maximum mobile adaptability without using the exposure scheme is 20cm / s, while the maximum mobile adaptability with using the scheme is 140cm / s;

[0048] Similarly, the mobility suitability of modules using traditional exposure modes is usually below 20cm / s, while that using high-exposure flash solutions can reach 2-3m / s, which is a huge improvement in mobility adaptability.

[0049] At the same time, the maximum lighting current using the traditional exposure scheme is 560mA, while that using the exposure scheme is 200mA. The reduction in current has lower design requirements for the selection of front-stage circuit devices and is more conducive to integrated use.

[0050] Example 2

[0051] An image recognition device comprises the current-limited high-explosive flash lighting system described in any one of the embodiments.

[0052] The image recognition equipment includes a barcode reading equipment, an optical character reading equipment, and a machine vision equipment.

[0053] In this embodiment, the current-limited high-exposure flash lighting circuit has the following features:

[0054] Current limiting module, boost module, energy storage module, constant current module and flash control module;

[0055] The flash control module includes a processor for controlling lighting synchronization, a lighting module and an image sensor;

[0056] The current limiting module is used to limit the current of the front stage, ensuring that the high current lighting of the rear stage does not affect the stability of the current power supply of the front stage;

[0057] The boost module is used to increase the power supply voltage of the lighting module to ensure the stability of voltage and current when multiple lamps are connected in series;

[0058] The energy storage module is used to store the energy of the lighting start-up device to ensure the current stability during lighting;

[0059] The constant current module is used to ensure constant current during lighting and consistent lighting brightness of LEDs in different bins;

[0060] The flash exposure control module is used to control the image sensor in the barcode scanner to turn on and off synchronously with the lighting, and to synchronize the lighting and exposure for a short period of time.

[0061] The above embodiments are only for illustration rather than limitation of the present invention, so all equivalent changes or modifications made according to the method described in the scope of the present patent application are included in the scope of the present patent application.

Claims

1. A current-limited high-explosion flash lighting system, characterized in that: include: A current limiting module (1), wherein an input end of the current limiting module (1) is connected to a power supply, and the current limiting module (1) detects a current value input by the power supply and outputs a current limiting current after implementing feedback regulation; A boost module (2), the input end of the boost module (2) being connected to the output end of the current limiting module (1); An energy storage module (3), the input end of the energy storage module (3) being connected to the output end of the boost module (2); A constant current module (4), the input end of the constant current module (4) being connected to the output end of the energy storage module (3); A flash control module (5), the flash control module (5) being respectively connected to the boost module (2), the energy storage module (3) and the constant current module (4); The flash control module (5) is composed of a main control chip (51), a lighting component (52), and an image sensor (53); the main control chip (51) is connected to the lighting component (52) and the image sensor (53), respectively, and controls the working states of the lighting component (52) and the image sensor (53).

2. A current-limited high-explosion flash lighting system according to claim 1, characterized in that: The energy storage module (3) comprises an aluminum electrolytic capacitor or a tantalum capacitor.

3. A current-limited high-explosion flash lighting system according to claim 2, characterized in that: The energy storage module (3) stores energy during non-lighting periods and outputs electrical energy during lighting periods.

4. A current-limited high-explosion flash lighting system according to claim 1, characterized in that: The voltage boost module (3) performs voltage boost processing on the current-limiting current output by the current-limiting module (1) to meet the operating voltage of the lighting component (52).

5. A current-limited high-explosion flash lighting system according to claim 1, characterized in that: The lighting assembly (52) is composed of a plurality of LEDs connected in series.

6. A current-limited high-explosion flash lighting system according to claim 1, characterized in that: The power source is a USB power supply or a handheld terminal battery.

7. An image recognition device, comprising the current-limited high-explosion flash lighting system according to any one of claims 1 to 6.

8. An image recognition device according to claim 7, characterized in that: The image recognition equipment includes a barcode reading equipment, an optical character reading equipment, and a machine vision equipment.

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