A system for reading information from an identification document
By combining OCR and RFID technologies, the document information reading system solves the problems of accuracy in document information recognition under multiple languages and different lighting conditions, as well as the insufficient recognition capability of various documents. It achieves efficient and accurate document information processing and fast RFID chip reading, and is suitable for efficient identity verification by border inspection, customs, civil aviation and other units.
Patent Information
- Application Number
- CN202521494069.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-17
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-07-17
AI Technical Summary
Existing entry and exit document information reading devices are insufficient in terms of accuracy in recognizing multiple languages and under different lighting conditions, as well as in recognizing various types of documents. Furthermore, the RFID chip reading efficiency is low, making it difficult to meet the high-efficiency identity verification needs of border inspection, customs, civil aviation, and other units.
By combining optical character recognition (OCR) technology with radio frequency identification (RFID) and multi-source image acquisition, and through the combination of image sensor circuits, radio frequency transceiver circuits, control and data processing circuits, USB interface circuits and host computer, efficient recognition and processing of document images and electronic information can be achieved.
It improves the accuracy and speed of document information recognition, supports the recognition of various documents, including passports, ID cards, driver's licenses and QR code electronic documents, and has fast RFID chip reading capabilities, making it suitable for various business scenarios such as banks and telecommunications service halls.
Smart Images
Figure CN224934413U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of data processing technology, specifically relating to a document information reading system and method. Background Technology
[0002] Multi-source image information acquisition and reading equipment for entry and exit documents is a specialized device for reading and verifying passports and other entry and exit documents. It is widely used in border inspection, customs, civil aviation, banking, and other business scenarios. Combining multiple technologies such as Optical Character Recognition (OCR), Radio Frequency Identification (RFID), infrared, and ultraviolet image acquisition, it can efficiently and accurately identify personal information such as the image, name, issuing country, and passport number on the data pages of passports and other entry and exit documents.
[0003] The development of domestically produced and controllable multi-source image information acquisition and reading equipment for entry and exit documents can effectively meet the application needs of border inspection, customs, civil aviation, banks and other units when checking and retaining document information. Utility Model Content
[0004] The purpose of this utility model is to provide a document information reading system and method.
[0005] The technical solution adopted by this utility model to solve the technical problem is as follows:
[0006] This utility model provides a document information reading system, which mainly includes:
[0007] Image sensor circuit, used to acquire document image information during OCR recognition operations;
[0008] Radio frequency transceiver circuit and radio frequency antenna are used to read electronic information on documents during RFID chip reading operations;
[0009] The control and data processing circuit is used to receive document image information acquired by the image sensor circuit and document electronic information read by the radio frequency transceiver circuit and radio frequency antenna, and to perform data processing on the document image information and document electronic information.
[0010] The USB interface circuit is used to receive data processed by the control and data processing circuit and to convert the data format.
[0011] The host computer is used to receive data after format conversion by the USB interface circuit and to parse the data.
[0012] The power supply circuit is connected to the image sensor circuit, the control and data processing circuit, and the USB interface circuit, respectively.
[0013] Furthermore, the USB interface circuit includes a USB interface chip; the USB interface chip converts parallel image data into USB format data and uploads the USB format data to the host computer.
[0014] Furthermore, the power supply circuit includes: a power chip, a first capacitor to a third capacitor, a first resistor to a fourth resistor, a power inductor, and a ferrite bead; a first pin of the power chip is connected to one end of a second resistor and one end of a first capacitor; one end of the first resistor is connected to the other end of a second resistor; a fifth pin of the power chip is connected to the connection terminal of the first resistor and the second resistor; a third pin of the power chip is connected to the other end of the first resistor and the other end of the first capacitor; a second pin of the power chip is connected to one end of the second capacitor and one end of the power inductor; the other end of the power inductor is connected to one end of the third resistor, one end of the third capacitor, and the ferrite bead; a sixth pin of the power chip is connected to the other end of the second capacitor; the other end of the third resistor is connected to one end of the fourth resistor; the other end of the fourth resistor is connected to the other end of the third capacitor; and a fourth pin of the power chip is connected to the connection terminal of the third resistor and the fourth resistor.
[0015] Furthermore, the image sensor circuit includes: an image sensor chip, fourth to seventh capacitors, and a fifth resistor; the twelfth and forty-seventh pins of the image sensor chip are connected to the fourth capacitor; the eleventh and thirty-ninth pins of the image sensor chip are connected to the fifth capacitor; the twenty-fifth, first, forty-eighth, twenty-third, and twenty-fourth pins of the image sensor chip are connected to the sixth capacitor; the thirteenth and fourteenth pins of the image sensor chip are connected to one end of the fifth resistor; and the sixteenth pin of the image sensor chip is connected to the other end of the fifth resistor and the seventh capacitor.
[0016] Furthermore, the control and data processing circuit includes: a microprocessor, capacitors eight through ten, resistors six through nine, and a passive crystal oscillator; the twentieth pin of the microprocessor is connected to the third pin of the passive crystal oscillator and one end of the eighth capacitor; the nineteenth pin of the microprocessor is connected to the first pin of the passive crystal oscillator and one end of the ninth capacitor; the other end of the eighth capacitor is connected to the other end of the ninth capacitor; the fourteenth pin of the microprocessor is connected to the sixth resistor and the tenth capacitor; the seventeenth pin of the microprocessor is connected to the seventh resistor; the eighteenth pin of the microprocessor is connected to the eighth resistor; and the forty-first pin of the microprocessor is connected to the ninth resistor.
[0017] Furthermore, the radio frequency transceiver circuit includes: a radio frequency base station chip, an impedance matching network, a power supply filter circuit, and a connector; the radio frequency base station chip is connected to the impedance matching network and the power supply filter circuit respectively; the connector is connected to the radio frequency antenna.
[0018] Furthermore, the impedance matching network includes: tenth to twelfth resistors, eleventh to fourteenth capacitors, a sixteenth capacitor, a second inductor, and a third inductor; the fourteenth pin of the RF base station chip is connected to the tenth resistor and the eleventh capacitor respectively; the other end of the tenth resistor is connected to the twelfth pin of the RF base station chip and the twelfth capacitor respectively; the other end of the twelfth capacitor is connected to one end of the eleventh resistor, and the other end of the eleventh resistor is connected to the third pin of the connector; the seventeenth pin of the RF base station chip is connected to one end of the second inductor, and the other end of the second inductor is connected to one end of the thirteenth capacitor and the fourth pin of the connector respectively; the sixteenth pin of the RF base station chip is connected to the other end of the thirteenth capacitor, one end of the fourteenth capacitor, and the fifth pin of the connector respectively; the fifteenth pin of the RF base station chip is connected to the third inductor, and the other end of the third inductor is connected to the other end of the fourteenth capacitor and the first pin of the connector respectively; the thirteenth pin of the RF base station chip is connected to one end of the sixteenth capacitor, the other end of the sixteenth capacitor is connected to one end of the twelfth resistor, and the other end of the twelfth resistor is connected to the second pin of the connector.
[0019] Furthermore, the power supply filtering circuit includes: a fifteenth capacitor and a first inductor; the eighteenth pin of the RF base station chip is connected to one end of the first inductor; and the other end of the first inductor is connected to the fifteenth capacitor.
[0020] This utility model provides a method for reading document information, implemented using the aforementioned document information reading system, and includes the following steps:
[0021] The image sensor circuit continuously acquires images of the acquisition area at a fixed frame rate, and converts the acquired light image signals into digital signals, which are then transmitted to the control and data processing circuit for data processing.
[0022] The control and data processing circuit controls the radio frequency transceiver circuit to read RFID chips through the radio frequency antenna. The read electronic information of the certificate is transmitted by the radio frequency transceiver circuit to the control and data processing circuit for data processing.
[0023] The data processed by the control and data processing circuits is converted into USB format and uploaded to the host computer via the USB interface circuit. Deep learning algorithms are then used to parse the data.
[0024] The beneficial effects of this utility model are:
[0025] 1. High recognition accuracy;
[0026] Employing advanced OCR (Optical Character Recognition) technology, this device can efficiently and accurately recognize various information on passports and other entry / exit documents, particularly the text information in the machine-readable zone (MRZ) of entry / exit documents. This invention performs exceptionally well under different language, font, and lighting conditions, significantly reducing the probability of misreading and missed readings.
[0027] 2. Supports recognition of multiple types of identification documents;
[0028] In addition to recognizing passports and other entry / exit documents, this device also supports the recognition of various other documents, including but not limited to ID cards, driver's licenses, vehicle registration certificates, and QR code electronic documents, demonstrating its strong multi-functionality. The application scenarios of this invention are not limited to document verification; it can also be widely used in bank account opening, card processing at telecommunications service centers, and ticket checking at scenic spots.
[0029] 3. Supports RFID (Radio Frequency Identification) chip reading;
[0030] This invention has the ability to read RFID chips and can quickly obtain biometric information (such as fingerprints, photos, etc.) from the built-in chip of an identification document.
[0031] 4. This utility model has a fast reading speed and strong data processing capability, and is suitable for scenarios that require efficient identity verification through biometrics.
[0032] 5. This utility model improves the accuracy of RFID chip reading and OCR recognition, and enhances the response speed and information processing capability for reading information on entry and exit documents. Attached Figure Description
[0033] Figure 1 This utility model provides a structural framework for a document information reading system.
[0034] Figure 2 This is a USB interface circuit.
[0035] Figure 3 This is a power supply circuit.
[0036] Figure 4 This is an image sensor circuit.
[0037] Figure 5 For control and data processing circuits.
[0038] Figure 6 This is a radio frequency transceiver circuit. Detailed Implementation
[0039] The present invention will be further described in detail below with reference to the accompanying drawings.
[0040] Firstly, this utility model provides a document information recognition system.
[0041] See Figure 1 As shown, the document information reading system provided by this utility model specifically includes the following modules:
[0042] USB interface circuit, power supply circuit, image sensor circuit, control and data processing circuit, RF transceiver circuit, RF antenna and host computer.
[0043] The USB interface circuit is connected to the power supply circuit, the control and data processing circuit, and the host computer. The power supply circuit is connected to the USB interface circuit, the image sensor circuit, and the control and data processing circuit. The image sensor circuit is connected to the power supply circuit and the control and data processing circuit. The control and data processing circuit is connected to the USB interface circuit, the power supply circuit, the image sensor circuit, and the RF transceiver circuit. The RF transceiver circuit is connected to the control and data processing circuit and the RF antenna. The main function of the power supply circuit is to provide power to the entire system.
[0044] The working principle of the document information reading system provided by this utility model is as follows:
[0045] When no identification is placed in the acquisition area, the image sensor circuit continuously acquires images of the acquisition area at a fixed frame rate, converts the acquired light image signals into digital signals, and transmits the image data to the control and data processing circuit for data processing and analysis.
[0046] When an ID is placed in the collection area, the image captured by the image sensor circuit differs from the image captured when no ID is placed. At this time, the image sensor circuit converts the captured light image signal into a digital signal and transmits the data to the control and data processing circuit. The control and data processing circuit compares the data to determine that an ID has been placed. At this point, formal ID information collection or RFID chip reading (if the ID has an electronic chip) can be performed.
[0047] In the first scenario, when formally collecting document information (OCR recognition), the image sensor circuit converts the collected light image signal into a digital signal and transmits it to the control and data processing circuit. The control and data processing circuit performs image processing on the received image data, converts it into JPEG format data, and transmits it to the USB interface circuit. The USB interface circuit converts it into USB format data and uploads it to the host computer for further processing, where the host computer parses the data according to relevant protocol standards.
[0048] In the second scenario, if the document contains an electronic chip, RFID chip reading is required via an RFID transceiver circuit and an RFID antenna. During RFID chip reading, the RFID transceiver circuit and antenna read the document. The control and data processing circuit controls the RFID transceiver circuit to read the electronic information of the document through the RFID antenna. This information is then transmitted by the RFID transceiver circuit to the control and data processing circuit, which in turn transmits it to the USB interface circuit. The USB interface circuit converts this information into USB format data and uploads it to the host computer for further processing. The host computer parses the data according to relevant protocol standards, and may use deep learning algorithms to infer and analyze the collected image data.
[0049] Specifically, the USB interface circuit mainly includes: USB interface chip U1; the USB interface chip U1 in the USB interface circuit is connected to the host computer, the USB interface chip U1 converts parallel image data into USB format data, and uploads the USB format data to the host computer.
[0050] Preferably, the USB interface chip U1 can be a CY7C68013A, and its circuit is as follows: Figure 2 As shown.
[0051] Specifically, such as Figure 3 As shown, the power supply circuit mainly includes: power chip U2, first capacitor C1, second capacitor C2, third capacitor C3, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, power inductor L14, and ferrite bead FB15.
[0052] The connections between them are as follows:
[0053] The first pin 1 of power chip U2 is connected to one end of the second resistor R2 and one end of the first capacitor C1; one end of the first resistor R1 is connected to the other end of the second resistor R2; the fifth pin 5 of power chip U2 is connected to the connection point of the first resistor R1 and the second resistor R2; the third pin 3 of power chip U2 is connected to the other end of the first resistor R1 and the other end of the first capacitor C1; the second pin 2 of power chip U2 is connected to one end of the second capacitor C2 and one end of the power inductor L14; the other end of the power inductor L14 is connected to one end of the third resistor R3, one end of the third capacitor C3, and the ferrite bead FB15; the sixth pin 6 of power chip U2 is connected to the other end of the second capacitor C2; the other end of the third resistor R3 is connected to one end of the fourth resistor R4; the other end of the fourth resistor R4 is connected to the other end of the third capacitor C3; the fourth pin 4 of power chip U2 is connected to the connection point of the third resistor R3 and the fourth resistor R4.
[0054] Among them, the power chip U2 mainly serves to step down and convert DC voltage; the first capacitor C1, the second capacitor C2, and the third capacitor C3 mainly serve to regulate and filter voltage; the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 mainly serve to provide voltage divider feedback, making the output voltage more accurate; the power inductor L14 achieves efficient and stable voltage conversion through energy storage and filtering, and has the functions of energy storage, smoothing current ripple, filtering, noise suppression, and smoothing system stability; the ferrite bead FB15 is used for high-frequency noise suppression and EMI filtering.
[0055] Preferably, the capacitance values of the first capacitor C1, the second capacitor C2, and the third capacitor C3 are 100nF (16V), 100nF (16V), and 22μF (25V), respectively; the resistance values of the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 are 100KΩ, 100KΩ, 56KΩ, and 10KΩ, respectively; the power inductor L14 is specifically selected as MWSA0518-4R7MT; and the ferrite bead FB15 is specifically selected as BLM21PG121SZ1D.
[0056] Specifically, such as Figure 4 As shown, the image sensor circuit mainly includes: image sensor chip U3, fourth capacitor C4, fifth capacitor C5, sixth capacitor C6, seventh capacitor C7 and fifth resistor R5.
[0057] The connections between them are as follows:
[0058] Pin 12 of image sensor chip U3 is connected to pin 47 and then to capacitor C4; pin 11 of image sensor chip U3 is connected to pin 39 and then to capacitor C5; pin 25, pin 1, pin 48, pin 48, pin 23, and pin 24 of image sensor chip U3 are connected and then to capacitor C6; pin 13 and pin 14 of image sensor chip U3 are connected and then to one end of resistor R5; pin 16 of image sensor chip U3 is connected to the other end of resistor R5 and capacitor C7.
[0059] The main function of the image sensor chip U3 is to convert the acquired light image signal into a digital signal. The fourth capacitor C4, the fifth capacitor C5, and the sixth capacitor C6 mainly serve to filter out power supply ripple and stabilize the voltage. The seventh capacitor C7 and the fifth resistor R5 form an RC charging circuit, which mainly delays the working time of the image sensor chip U3 after power-on, ensuring that the image sensor chip U3 starts working only after the power supply voltage is stable, thus ensuring the stability of the working state of the image sensor chip U3.
[0060] Preferably, the capacitance values of the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, and the seventh capacitor C7 are 100nF (16V), 10μF (10V), 10μF (10V), and 1μF (16V), respectively; and the resistance value of the fifth resistor R5 is 1K.
[0061] Specifically, such as Figure 5 As shown, the control and data processing circuit mainly includes: microprocessor U4, eighth capacitor C8, ninth capacitor C9, tenth capacitor C10, sixth resistor R6, seventh resistor R7, eighth resistor R8, ninth resistor R9 and passive crystal oscillator X1.
[0062] The connections between them are as follows:
[0063] Pin 20 of microprocessor U4 is connected to pin 3 of passive crystal oscillator X1 and one end of capacitor C8; pin 19 of microprocessor U4 is connected to pin 1 of passive crystal oscillator X1 and one end of capacitor C9; the other end of capacitor C8 is connected to the other end of capacitor C9; pin 14 of microprocessor U4 is connected to resistor R6 and capacitor C10; pin 17 of microprocessor U4 is connected to resistor R7; pin 18 of microprocessor U4 is connected to resistor R8; pin 41 of microprocessor U4 is connected to resistor R9.
[0064] Preferably, the microprocessor U4 can specifically use the PGL50G FPGA chip from Unisplendour for data processing, data analysis, and RF card reading control.
[0065] Preferably, the capacitance values of the eighth capacitor C8, the ninth capacitor C9, and the tenth capacitor C10 are 20Pf / 10V, 20Pf / 10V, and 100nF / 10V, respectively; and the resistance values of the sixth resistor R6, the seventh resistor R7, the eighth resistor R8, and the ninth resistor R9 are 47KΩ, 0Ω, 0Ω, and 10KΩ, respectively.
[0066] Specifically, such as Figure 6 As shown, the RF transceiver circuit mainly includes: an RF base station chip U5, an impedance matching network, a power supply filter circuit, and a connector J6. The RF base station chip U5 is connected to both the impedance matching network and the power supply filter circuit; the RF transceiver circuit is connected to the RF antenna via connector J6.
[0067] The RF base station chip U5 is primarily used to control the switching of the RF antenna and to interact with the card reader in the RFID (Radio Frequency Identification) system. The impedance matching network is mainly used to optimize the antenna's card reading performance. Because the parameters and performance of passports or other valid electronic documents from different countries are difficult to maintain consistently, the sensitivity and response frequency of these documents also vary. To ensure stable reading of different electronic documents from various countries, impedance matching of the antenna is necessary. The specific functions of impedance matching are mainly as follows:
[0068] 1. Maximize power transmission and improve signal efficiency;
[0069] 2. Reduce the standing wave ratio (VSWR) to decrease signal distortion;
[0070] 3. Adapt to complex environments and enhance system robustness;
[0071] 4. Optimize bandwidth and frequency response;
[0072] 5. Improve tag reading distance and stability.
[0073] The power supply filter circuit is mainly used for:
[0074] 1. Suppress electromagnetic interference (EMI);
[0075] 2. Improve power supply purity and stability, i.e. eliminate ripple noise and stabilize output voltage;
[0076] 3. Suppress interference from molds and tools.
[0077] Specifically, the impedance matching network mainly includes: tenth resistor R10, eleventh resistor R11, twelfth resistor R12, eleventh capacitor C11, twelfth capacitor C12, thirteenth capacitor C13, fourteenth capacitor C14, sixteenth capacitor C16, second inductor L2, and third inductor L3; pin 14 of RF base station chip U5 is connected to the tenth resistor R10 and the eleventh capacitor C11 respectively; the other end of the tenth resistor R10 is connected to pin 12 of RF base station chip U5 and the twelfth capacitor C12 respectively; the other end of the twelfth capacitor C12 is connected to one end of the eleventh resistor R11, and the other end of the eleventh resistor R11 is connected to pin 3 of connector J6; pin 17 of RF base station chip U5 is connected to the second inductor L2 and the third inductor L3. One end of inductor L2 is connected to the first inductor, and the other end of inductor L2 is connected to one end of capacitor C13 and pin 4 of connector J6. Pin 16 of RF base station chip U5 is connected to the other end of capacitor C13, one end of capacitor C14 and pin 5 of connector J6. Pin 15 of RF base station chip U5 is connected to inductor L3, and the other end of inductor L3 is connected to the other end of capacitor C14 and pin 1 of connector J6. Pin 13 of RF base station chip U5 is connected to one end of capacitor C16, and the other end of capacitor C16 is connected to one end of resistor R12, and the other end of resistor R12 is connected to pin 2 of connector J6.
[0078] Specifically, the power supply filtering circuit mainly includes: a fifteenth capacitor C15 and a first inductor L1; the eighteenth pin of the RF base station chip U5 is connected to one end of the first inductor L1; and the other end of the first inductor L1 is connected to the fifteenth capacitor C15.
[0079] Preferably, the resistance values of the tenth resistor R10, the eleventh resistor R11, and the twelfth resistor R12 are 2K, 15K, and 15K, respectively; and the capacitance values of the eleventh capacitor C11, the twelfth capacitor C12, the thirteenth capacitor C13, the fourteenth capacitor C14, the fifteenth capacitor C15, and the sixteenth capacitor C16 are 100nF (16V), 1nF (25V), 22pF (25V), 22pF (25V), 22μF (16V), and 1nF (25V), respectively.
[0080] The specific connection relationships between the power supply circuit, image sensor circuit, control and data processing circuit, and USB interface circuit are as follows:
[0081] The ferrite bead FB15 in the power supply circuit is connected to the fourth capacitor C4, the fifth capacitor C5, the sixth capacitor C6, the seventh capacitor C7, and the fifth resistor R5 in the image sensor circuit; the ferrite bead FB15 in the power supply circuit is connected to the sixth resistor R6, the ninth resistor R9, and the microprocessor U4 in the control and data processing circuit; the ferrite bead FB15 in the power supply circuit is connected to the USB interface chip U1 in the USB interface circuit.
[0082] The specific connection relationships between the control and data processing circuit, the image sensor circuit, the RF transceiver circuit, and the USB interface circuit are as follows:
[0083] The microprocessor U4 in the control and data processing circuit is connected to the image sensor chip U3 in the image sensor circuit; the microprocessor U4 in the control and data processing circuit is connected to the radio frequency base station chip U5 in the radio frequency transceiver circuit; the seventh resistor R7 and the eighth resistor R8 in the control and data processing circuit are respectively connected to the USB interface chip U1 in the USB interface circuit.
[0084] Secondly, this utility model provides a document information reading system method, which is mainly implemented through the document information reading system provided in the first aspect.
[0085] The present invention provides a method for reading document information, the specific implementation process of which is as follows:
[0086] In the first scenario, when formally collecting document information (OCR recognition), the image sensor circuit converts the collected light image signal into a digital signal and transmits it to the control and data processing circuit. The control and data processing circuit performs image processing on the received image data, converts it into JPEG format data, and transmits it to the USB interface circuit. The USB interface circuit converts it into USB format data and uploads it to the host computer for further processing, where the host computer parses the data according to relevant protocol standards.
[0087] In the second scenario, if the document contains an electronic chip, RFID chip reading is required via an RFID transceiver circuit. During RFID chip reading, the RFID transceiver circuit reads the document using radio frequency (RF). The control and data processing circuit controls the RF transceiver circuit to read the document information via an RF antenna. The information read is then transmitted by the RF transceiver circuit to the control and data processing circuit. The control and data processing circuit then uploads the read information to the host computer via a USB interface circuit for further processing. The host computer parses the data according to relevant protocol standards.
[0088] 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 they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these 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 document information reading system, characterized in that, include: Image sensor circuit, used to acquire document image information during OCR recognition operations; Radio frequency transceiver circuit and radio frequency antenna are used to read electronic information on documents during RFID chip reading operations; The control and data processing circuit is used to receive document image information acquired by the image sensor circuit and document electronic information read by the radio frequency transceiver circuit and radio frequency antenna, and to perform data processing on the document image information and document electronic information. The USB interface circuit is used to receive data processed by the control and data processing circuit and to convert the data format. The host computer is used to receive data after format conversion by the USB interface circuit and to parse the data. The power supply circuit is connected to the image sensor circuit, the control and data processing circuit, and the USB interface circuit, respectively.
2. The document information reading system according to claim 1, characterized in that, The USB interface circuit includes a USB interface chip; the USB interface chip converts parallel image data into USB format data and uploads the USB format data to the host computer.
3. The document information reading system according to claim 1, characterized in that, The power supply circuit includes: a power chip, a first capacitor to a third capacitor, a first resistor to a fourth resistor, a power inductor, and a ferrite bead; the first pin of the power chip is connected to one end of the second resistor and one end of the first capacitor; one end of the first resistor is connected to the other end of the second resistor; the fifth pin of the power chip is connected to the connection terminal of the first resistor and the second resistor; the third pin of the power chip is connected to the other end of the first resistor and the other end of the first capacitor; the second pin of the power chip is connected to one end of the second capacitor and one end of the power inductor; the other end of the power inductor is connected to one end of the third resistor, one end of the third capacitor, and the ferrite bead; the sixth pin of the power chip is connected to the other end of the second capacitor; the other end of the third resistor is connected to one end of the fourth resistor; the other end of the fourth resistor is connected to the other end of the third capacitor; and the fourth pin of the power chip is connected to the connection terminal of the third resistor and the fourth resistor.
4. The document information reading system according to claim 1, characterized in that, The image sensor circuit includes: an image sensor chip, capacitors four through seven, and a resistor; pins 12 and 47 of the image sensor chip are connected to the fourth capacitor; pins 11 and 39 of the image sensor chip are connected to the fifth capacitor; pins 25, 1, 48, 23, and 24 of the image sensor chip are connected to the sixth capacitor; pins 13 and 14 of the image sensor chip are connected to one end of the fifth resistor; and pin 16 of the image sensor chip is connected to the other end of the fifth resistor and the seventh capacitor.
5. The document information reading system according to claim 1, characterized in that, The control and data processing circuit includes: a microprocessor, capacitors eight through ten, resistors six through nine, and a passive crystal oscillator; the twentieth pin of the microprocessor is connected to the third pin of the passive crystal oscillator and one end of the eighth capacitor; the nineteenth pin of the microprocessor is connected to the first pin of the passive crystal oscillator and one end of the ninth capacitor; the other end of the eighth capacitor is connected to the other end of the ninth capacitor; the fourteenth pin of the microprocessor is connected to the sixth resistor and the tenth capacitor; the seventeenth pin of the microprocessor is connected to the seventh resistor; the eighteenth pin of the microprocessor is connected to the eighth resistor; and the forty-first pin of the microprocessor is connected to the ninth resistor.
6. The document information reading system according to claim 1, characterized in that, The radio frequency transceiver circuit includes: a radio frequency base station chip, an impedance matching network, a power supply filter circuit, and a connector; the radio frequency base station chip is connected to the impedance matching network and the power supply filter circuit respectively; the connector is connected to the radio frequency antenna.
7. The document information reading system according to claim 6, characterized in that, The impedance matching network includes: resistors 10 to 12, capacitors 11 to 14, capacitor 16, a second inductor, and a third inductor; pin 14 of the RF base station chip is connected to resistor 10 and capacitor 11 respectively; the other end of resistor 10 is connected to pin 12 of the RF base station chip and capacitor 12 respectively; the other end of capacitor 12 is connected to one end of resistor 11, and the other end of resistor 11 is connected to pin 3 of connector; pin 17 of the RF base station chip is connected to one end of the second inductor, and the other end of the second inductor is connected to one end of capacitor 13 and pin 4 of connector respectively; pin 16 of the RF base station chip is connected to the other end of capacitor 13, one end of capacitor 14, and pin 5 of connector respectively; pin 15 of the RF base station chip is connected to the third inductor, and the other end of the third inductor is connected to the other end of capacitor 14 and pin 1 of connector respectively; pin 13 of the RF base station chip is connected to one end of capacitor 16, the other end of capacitor 16 is connected to one end of resistor 12, and the other end of resistor 12 is connected to pin 2 of connector.
8. A document information reading system according to claim 6, characterized in that, The power supply filtering circuit includes a fifteenth capacitor and a first inductor; the eighteenth pin of the RF base station chip is connected to one end of the first inductor; the other end of the first inductor is connected to the fifteenth capacitor.