A banknote paper sheet quality confirmation operation system, control method, and recording method

Abstract

The application provides a banknote paper quality confirmation operation system, a control method and a recording method, which comprise a to-be-inspected paper bin, an inspection platform and a finished paper bin, wherein the banknote paper stored in the to-be-inspected paper bin is banknote paper that has been preliminarily detected and identified by a previous device; an operation plane, the operation plane is a light-transmitting transparent layer with a thickness of 5-15 mm made of a transparent material; an image vision module, the image vision module is arranged on the lower end surface of the operation plane, the image vision module forms a banknote pattern projection at the contact surface part of the operation plane, and the image vision module emits parallel visible light from bottom to top; an identification module, the identification module is arranged above the operation plane, and the identification module is used for identifying the identity code of the banknote paper; and a control module, the control module acquires the identity code identified by the identification module, acquires the invalid matrix data from a data table, performs high-light display on the defect area identified by the previous device during manual checking, and records the defect area after manual detection is completed.

Description

Technical Field

[0001] This invention relates to the field of banknote paper quality inspection technology, and in particular to a banknote paper quality confirmation operating system, control method, and recording method. Background Technology

[0002] The paper selection platform is a production tool used in the banknote paper production process for manual verification of paper quality. It typically consists of three modules: a "paper loading table," a "lightbox," and a "paper receiving table." The lightbox has a transparent glass surface on which films containing different images and text are pasted, providing reference lines to assist operators in determining whether the positions of anti-counterfeiting elements such as watermarks and security threads meet standards. However, current visual image detection technology used in banknote paper inspection still results in missed or incorrect detections, making it difficult to introduce efficient and rapid modern technology into banknote paper inspection and thus hindering production efficiency. Furthermore, although paper defect information is collected and recorded, it cannot be "synchronously located" with the paper seen by the operator during review. This prevents manual judgment based on defect data, reducing work efficiency and increasing the likelihood of misjudgments or missed detections.

[0003] However, the traditional lightbox combined with transparent glass inspection method has the following drawbacks: 1. Traditional paper selection platforms typically use point or line light sources. Both of these inevitably result in low light intensity and insufficient illumination in edge areas. Maintaining the original light intensity or increasing it will cause irreversible damage to the eyesight of staff. Furthermore, the projected size of patterns varies due to different light directions. For different banknote templates, the distance between the light source and the glass plate needs to be adjusted to ensure the pattern size meets the requirements.

[0004] 2. The installation of light boxes and transparent glass will both produce a shadowless lamp effect, that is, the projection of patterns parallel to the light source is clearer, while the projection of patterns at an angle to the light source becomes blurry or even distorted.

[0005] 3. Defective areas still need to be marked and circled by staff using markers, which prolongs the working time and reduces work efficiency.

[0006] 4. The current system lacks a linkage mechanism with touch or interactive systems. Operators cannot input the coordinates of identified defects into the system, nor can they establish a complete quality traceability chain in the database. Subsequent processes cannot accurately scrap the defective sheets based on the defect coordinates, and the entire sheet must be discarded, resulting in a waste of resources.

[0007] 5. The current paper selection process relies mainly on manual judgment and operation, lacking the support of intelligent auxiliary systems, which cannot meet the management needs of the modern banknote printing industry for efficient, traceable, and low-cost production. Summary of the Invention

[0008] To address the aforementioned technical problems and integrate existing visual image module quality inspection technology into the banknote inspection process, this invention provides a banknote paper quality verification operating system, control method, and recording method. This invention is implemented as follows: A banknote paper quality verification operating system, comprising: The paper storage compartment is for inspection, the inspection platform is for inspection, and the paper storage compartment is for completed inspection. The paper storage compartment contains banknotes that have been preliminarily inspected and identified by the preceding equipment. The testing platform includes: The operating surface is a transparent layer with a thickness of 5-15mm made of transparent material; An image vision module is disposed on the lower surface of the operating plane. The image vision module forms a banknote pattern projection at the contact surface with the operating plane, and the image vision module emits parallel visible light from bottom to top. The identification module is arranged at intervals directly above the operating plane, and the identification module is used to identify the identity code of the banknote; The control module acquires the identity code identified by the identification module, retrieves invalidation matrix data from the data table, highlights the defective areas identified in the preceding equipment during manual verification, and records the defective areas after manual inspection is completed.

[0009] As a further improvement, the inspection platform also includes an operating system, which is used to receive inspection information directly input by humans, and to re-mark the defective areas of the paper to be inspected or cancel the marking of defective areas that were misidentified in the preceding equipment based on the inspection information. The display module is located on the inspection platform at a position that is offset from the operation platform, the image vision module, and the recognition module. The display module is used to display the identification code of the paper.

[0010] As a further improvement, the image vision module includes a light source layer that can emit visible light from bottom to top, a filter layer is disposed above the light source layer, and a display layer is disposed above the filter layer.

[0011] As a further improvement, the light source layer is an LED matrix, and the filter layer includes a diffuse reflector plate disposed above the light source layer and a honeycomb grating disposed above the diffuse reflector plate.

[0012] As a further improvement, the light source layer includes several light-shielding plates corresponding to the boundaries of each area on the banknote paper. The light-shielding plates divide the light source layer into several lighting units, and each lighting unit is provided with an LED point light source. The filter layer is a Fresnel lens.

[0013] As a further improvement, the intensity of the visible light emitted by the visual module after passing through the paper is 150~350lm, and the visible light is cool-colored light.

[0014] As a further improvement, the paper output direction of the paper tray to be inspected, the paper feed direction of the inspection platform, the paper output direction of the inspection platform, and the paper feed direction of the paper tray to be inspected are multiple tangents of the same arc, and the angle between the paper output direction of the paper tray to be inspected and the paper feed direction of the paper tray to be inspected is 5~20°.

[0015] A control method for a banknote paper quality verification operating system, applied to any of the banknote paper quality verification operating systems described above, includes the following steps: S1. The banknotes in the paper compartment to be inspected are manually removed and placed on the operating surface and aligned. S2. The identification module obtains the identity code of the banknote and retrieves its invalidation matrix data from the data table Data_Piece. If the converted value of the matrix is ​​not 0, the invalidation opening information is calculated, and the background drawing of the known invalidation opening is highlighted for 1~5 seconds. S3. Manual inspection: The highlighted areas are manually inspected. If the highlighted areas are indeed defective, the staff will click the "Single Opening Cancel" button and select the highlighted areas. Otherwise, they will select the "Single Opening Mark Good" button and select the highlighted areas. The canceled areas will be marked with a red box by the image vision module. S4. Manual inspection: Staff will screen the non-highlighted areas based on the overlap information between the projected pattern and the banknote paper pattern. If a defect is found in one of the open areas, click the "Single Opening Cancelled" button and select the corresponding area. The cancelled area will be marked with a red box by the image vision module. S5. After a single banknote is verified, the staff clicks the "Complete Inspection" button, and the control module collects the corresponding invalid area information and updates it to a new data table for storage.

[0016] A method for recording defective paper in a banknote paper quality verification operating system, applied to any of the banknote paper quality verification operating systems described above, wherein the steps are completed in the preliminary detection and identification by the preceding equipment, and the method for recording the location of defects on a single sheet of paper uses a binary matrix identifier to achieve compressed storage, and the specific algorithm includes the following steps: A1. Mark the banknote opening position matrix. To be close to the habits of the subsequent process, take the upper right corner of the front as the first opening, and add them one by one from top to bottom and from right to left. A2. Use binary 0 and 1 to indicate whether the current ticket is invalid; A3. The nth root corresponds to 2n-1 binary bits; A4. The XOR function can be used on binary sequences to determine whether a specified open bit is invalid.

[0017] The beneficial effects of this invention are as follows: 1. Optimizing the light source of the paper selection platform to parallel light reduces edge blurring caused by point or line light sources, minimizes the shadowless lamp effect, increases the overall illumination intensity of the detection area, and reduces the light intensity difference between the brightest and darkest areas, thus reducing damage to the eyesight of staff. Furthermore, parallel light ensures that the projected pattern remains undistorted, eliminating the need to adjust the light source distance according to different banknote types and sizes.

[0018] 2. Add control and recognition modules to perform preliminary visual image checks before manual verification, and assign an identification number to each banknote. After the initial screening, mark the areas with defects that appear during the initial screening process to reduce the workload of staff and improve overall work efficiency. Attached Figure Description

[0019] Figure 1 This is a top view of the spatial layout of the quality verification operating system provided by the present invention.

[0020] Figure 2 This is a front view schematic diagram of the spatial layout of the quality verification operating system provided by the present invention.

[0021] Figure 3 This diagram illustrates the principle of creating a vignetting effect from a point light source.

[0022] Figure 4 This is a schematic diagram of the dark corner shape of a point light source.

[0023] Figure 5 This is a schematic diagram of the vignetting shape of a line light source.

[0024] Figure 6 Clear comparison images of different warm and cool colors.

[0025] Figure 7 This diagram illustrates the vertical shadowless lamp effect caused by a linear light source.

[0026] Figure 8 This is a schematic diagram of the layered structure of the liquid crystal display used in Embodiment 4 of the present invention.

[0027] Figure 9This is a schematic diagram illustrating the principle of liquid crystal torsion light polarization direction in Embodiment 4 of the present invention.

[0028] Figure 10 This is a schematic diagram of the capacitive touchscreen structure in Embodiment 4 of the present invention.

[0029] Figure 11 This is a schematic diagram of the parallel light source forming principle in Embodiment 5 of the present invention.

[0030] Figure 12 This is a schematic diagram of the imaging effect in Embodiment 5 of the present invention.

[0031] Figure 13 This is a schematic diagram of the parallel light source forming principle in Embodiment Six of the present invention.

[0032] Figure 14 This is a schematic diagram of the imaging effect in Embodiment Six of the present invention.

[0033] Figure 15 This is a schematic diagram of the operation plane state when highlighting the defect area recorded in the preceding detection process in this invention.

[0034] Figure 16 This is a schematic diagram of the operation plane state that prompts manual confirmation when a defect occurs in this invention.

[0035] Figure 17 This is a schematic diagram of the working plane state after manual marking as waste in this invention. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0037] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0038] A banknote paper quality verification operating system, comprising: The paper storage compartment is for inspection, the inspection platform is for inspection, and the paper storage compartment is for completed inspection. The paper storage compartment contains banknotes that have been preliminarily inspected and identified by the preceding equipment. The testing platform includes: The operating surface is a transparent layer with a thickness of 5-15mm made of transparent material; An image vision module is disposed on the lower surface of the operating plane. The image vision module forms a banknote pattern projection at the contact surface with the operating plane, and the image vision module emits parallel visible light from bottom to top. The identification module is arranged at intervals directly above the operating plane, and the identification module is used to identify the identity code of the banknote; The control module acquires the identity code identified by the identification module, retrieves invalidation matrix data from the data table, highlights the defective areas identified in the preceding equipment during manual verification, and records the defective areas after manual inspection is completed.

[0039] As a further improvement, the inspection platform also includes an operating system, which is used to receive inspection information directly input by humans, and to re-mark or cancel the marking of defective areas of the paper to be inspected based on the inspection information. The operating system can be a mechanical button or a touch control; including infrared touch, capacitive touch, projected capacitive or laser excitation, etc. In specific scenarios, a non-contact laser pointing system can be used to replace physical touch to prevent product contamination.

[0040] The display module is located on the inspection platform at a position offset from the operation platform, the image vision module, and the recognition module. The display module is used to display the paper's identification code, the inspection information entered by the worker, operation prompts, etc.

[0041] In this application, the surface layout of the inspection platform is not limited, that is, the location of the operating system and display module is not limited. Those skilled in the art can arrange them reasonably according to actual operational needs or worker requirements.

[0042] As a further improvement, the image vision module includes a light source layer that can emit visible light from bottom to top, a filter layer is disposed above the light source layer, the light emitted by the light source layer becomes parallel light after passing through the filter layer, and a display layer is disposed above the filter layer.

[0043] Reference Figures 15-17 A control method for a banknote paper quality verification operating system, applied to any of the banknote paper quality verification operating systems described above, includes the following steps: S1. The banknotes in the paper compartment to be inspected are manually removed and placed on the operating surface and aligned. S2. The identification module obtains the identity code of the banknote and retrieves its invalidation matrix data from the data table Data_Piece. If the converted value of the matrix is ​​not 0, the invalidation opening information is calculated, and the background drawing of the known invalidation opening is highlighted for 1~5 seconds. S3. Manual inspection: The highlighted areas are manually inspected. If the highlighted areas are indeed defective, the staff will click the "Single Opening Cancel" button and select the highlighted areas. Otherwise, they will select the "Single Opening Mark Good" button and select the highlighted areas. The canceled areas will be marked with a red box by the image vision module. S4. Manual inspection: Staff will screen the non-highlighted areas based on the overlap information between the projected pattern and the banknote paper pattern. If a defect is found in one of the open areas, click the "Single Opening Cancelled" button and select the corresponding area. The cancelled area will be marked with a red box by the image vision module. S5. After a single banknote is verified, the staff clicks the "Complete Inspection" button, and the control module collects the corresponding invalid area information and updates it to a new data table for storage.

[0044] The present invention also provides a defective paper recording method for a banknote paper quality confirmation operating system, which is applied to any of the banknote paper quality confirmation operating systems described above, and the steps are completed in the preliminary detection and identification of the preceding equipment.

[0045] The system focuses on the smallest granularity of defect location at the "opening" level. This means that multiple defects on the same small-opening product are not distinguished; only the current opening is recorded as invalid. Therefore, there are 240 possible defect distribution patterns on a 40-opening product.

[0046] If 40 keys are added to the single-sheet data table to determine whether each small sheet is void, the readability of the data table will be severely reduced, and it will lack scalability. If a new table is created for each small sheet and linked to the Data_Piece table for management, another dimension will be added to the data structure. During the later trial period, the efficiency of joint queries based on massive amounts of data will be difficult to guarantee.

[0047] For the above reasons, the method for recording the defect location of a single sheet of paper uses a binary matrix identifier to achieve compressed storage. Only one 5-byte field is needed to effectively store the invalidation status of each open position. The specific algorithm includes the following steps: A1. Mark the banknote opening position matrix. To be close to the habits of the subsequent process, take the upper right corner of the front as the first opening, and add them one by one from top to bottom and from right to left. A2. Use binary 0 and 1 to indicate whether the current ticket is invalid; A3. The nth root corresponds to 2n-1 binary bits; A4. The XOR function can be used on binary sequences to determine whether a specified open bit is invalid.

[0048] Example: A certain product has a total of 40K tickets, of which the 1K, 15K, 16K, and 38K are invalid tickets, and the remaining tickets are valid. Then its invalid ticket information matrix is:

[0049] The binary sequence is: Bin[1000 0000 0000 0011 0000 0000 0000 0000 0000 0100]; The hexadecimal sequence is: Hex[80 03 00 00 04]; Storing the number 137439002625 in the database will identify the status of this invalidated distribution. The same applies to reverse decoding.

[0050] Where K is an open root number.

[0051] To improve the work efficiency of staff and reduce the physical strain caused by repetitive labor, this invention also makes corresponding improvements to the layout and structure of the uninspected paper bin, the inspection platform, and the completed paper bin: First, the hardware of the operating system needs to be improved based on ergonomics. Ergonomics, also known as human factors engineering or human factors science, is an interdisciplinary field between human science and technological science. It studies the relationship between humans, machines, and the environment. In the mechanical industry, ergonomics focuses on how to make the operation methods and working environment of designed machines, tools, and complete sets of equipment more suitable for the requirements of operators.

[0052] Since the primary operators of the paper selection platform are women, the design was based on the national standard "[GB10000-88] Human Body Dimensions of Chinese Adults" to test whether the positions and angles of the platform's components were within a reasonable range. A three-dimensional human body model was established with reference to the average body dimensions of Chinese women aged 18-55.

[0053] The traditional arrangement is a straight rectangular installation with all three platforms at the same height. This installation method is simple to manufacture, but prolonged operation can easily lead to operator fatigue.

[0054] To reduce ineffective movements and lower labor intensity in production, the height and angle of the three modules were redesigned using SolidWorks tools. Testing was conducted using the previously created human body model to ensure that the products and buttons to be operated are within easy reach of the human hand while seated. Therefore, please refer to the attached instruction manual. Figure 1 As a further improvement, the paper output direction of the paper tray to be inspected, the paper feed direction of the inspection platform, the paper output direction of the inspection platform, and the paper feed direction of the finished paper tray are multiple tangents of the same arc, and the angle between the paper output direction of the paper tray to be inspected and the paper feed direction of the finished paper tray is 5~20°, that is, the vertical projections of the paper tray to be inspected, the inspection platform, and the finished paper tray are located within the same arc region. In the attached diagram, the area marked with the paper to be selected is the paper tray area, the paper selection operation area is the inspection platform area, and the finished storage area is the finished paper tray area.

[0055] At the same time, for this purpose, refer to Figure 2 As a further improvement, the installation height gradually decreases from the paper tray to the paper tray after inspection. During the production process, the operator's actions of extracting, inspecting, and sorting products result in a downward flow of the product, lowering the paper's center of gravity by 230mm. Based on an average paper weight of 16kg per ream, this reduces physical exertion by 36 joules per ream produced, lowering labor intensity compared to traditional horizontally distributed paper sorting tables.

[0056] Furthermore, the inspection platform forms a 10° angle with the ground facing the operator, and the products to be sorted will automatically align with the ruler under the action of gravity; at the same time, the tilt angle reduces the bending and head-down movements of the operator when operating the remote touch area of ​​the touch screen, reducing the pressure on the lumbar and cervical spine during the work process.

[0057] The paper collection table has four legs of varying heights, and the tabletop is designed with a slant, forming a 15° angle with the ground, with the lowest point being the front left corner. After large sheets of paper are manually sorted and placed on the table, they automatically align themselves under gravity, reducing the need for manual alignment.

[0058] In addition to reducing joint and muscle strain and improving work efficiency, it is also necessary to consider the eyesight of the staff. Luminance, also known as brightness, is a physical quantity that represents the actual intensity of light emitted or reflected by the human eye from a light source or the surface of an illuminated object.

[0059] Reference Figures 3-5Because of differences in the angle of incidence and the distance from which light is irradiated, the light intensity received per unit area at different locations on the observed paper varies. The illuminance caused by a point light source is inversely proportional to the square of the distance from the light source to the illuminated surface, and directly proportional to the angle between the axis of the light beam and the normal to the illuminated surface. Therefore, regardless of whether fluorescent lamps (linear light sources) or incandescent lamps (point light sources) are used in the light box of a traditional paper sorting platform, it is unavoidable that the center is bright and the edges are dark.

[0060] Color temperature is a physical quantity used in lighting optics to define the color of a light source. Specifically, it refers to the temperature at which a black body, when heated to a certain temperature, emits light that matches the color of light emitted by a given light source. This heated temperature is called the color temperature of the light source, often simply called color temperature, and is expressed in Kelvin (K). Light with a low color temperature appears yellowish, such as incandescent bulbs around 2800K, while light with a high color temperature appears bluish, such as ultraviolet lamps above 9000K.

[0061] At different color temperatures, the brightness required for human eyes to observe objects varies, and the level of eye fatigue also differs. Therefore, various light source tests were conducted on the selection of light source brightness and color temperature. The brightness was adjusted to a level that was comfortable for the operator's eyes and made it easy to see paper defects after placing the product. The following data was obtained: Table 1. Survey of Color Temperature and Brightness of Light Sources for Visual Comfort (Unit: Lumens):

[0062] As a further improvement, the intensity of the visible light emitted by the visual module after passing through the paper is 150~350lm, and the visible light is cool-colored light.

[0063] And based on the type of light source, besides Figures 3-5 In addition to the vignetting issue, the following problems may also occur: 1) Shadowless lamp effect: Reference Figure 7 Because there is an operating plane made of transparent material with a thickness of 5~15mm above the image vision module, lines parallel to the light source can be imaged, while vertical lines become very blurry and indistinguishable under the shadowless lamp effect.

[0064] (ii) Magnification: Reference Figure 8If the light source is a point source, the projection of the pattern on the light source layer will be magnified, and this phenomenon becomes more pronounced as the angle between the pattern's normal direction and the incident direction of the light source increases. To ensure that the size of the image projected onto the paper matches the design artwork, the corrected position of each pixel needs to be recalculated based on the distance and angle of the light source within the lightbox. This operation is computationally complex, and the computational load increases dramatically with the increase in film resolution. Furthermore, when the relative position of the light source and the screen changes, the image scaling calculation result will deviate from the actual projection result. Therefore, using a point source as the projection light source for a lightbox has inherent drawbacks.

[0065] A solution that effectively reduces vignetting while avoiding shadowless lamp effects and magnification deviations is to use a parallel light source. However, how to place this parallel light source within a limited testing platform presents a new technical challenge. To address these issues, this invention provides the following embodiments: Example 1 Building upon the basic embodiment, as a further improvement, the visual imaging module is an ultra-short-throw projector, and the operating plane is a transparent glass plate. The ultra-short-throw projector projects onto the transparent glass plate from below, and defect indications are displayed on the paper area through image control. In this embodiment, an operation panel is also provided on the side of the operating plane. The operation panel has several operation buttons, which are electrically connected to the control module. The user can input a discarded area number via the operation buttons. After input, a corresponding frame appears in the corresponding area, requiring confirmation before the area is marked as discarded.

[0066] The light source in this embodiment may not be a parallel light source.

[0067] Example 2 Based on Embodiment 1, the backlight is retained, and the ultra-short-throw projectors are spaced above the operating plane.

[0068] The light source in this embodiment may not be a parallel light source.

[0069] Example 3 Based on Embodiment 1, an ultra-short-throw projector is used instead of a point light source and is positioned below the operating plane.

[0070] The light source in this embodiment may not be a parallel light source.

[0071] Example 4 Building upon the basic embodiment, the image vision module employs a controllable LED matrix positioned below the paper selection platform, illuminating only the defective areas; the operating plane is a transparent glass plate. This design offers lower cost and is suitable for production line environments where high interactive precision is not required but rapid prompts are necessary.

[0072] The light source in this embodiment may not be a parallel light source.

[0073] Example 5 As a further improvement on the basic embodiment, the visual imaging module is a transparent LCD screen, and the operating plane is a touch-sensitive capacitive screen. In this embodiment, the human-computer interaction unit is a touch-based interaction, the paper selection platform supports touch, and the operator can directly click on the location of paper defects; the click action is accurately recorded by the system as defect coordinates and marked in the image; the input result is bound to the paper number and written into the database for subsequent use.

[0074] Specifically, refer to Figure 8 The transparent liquid crystal screen comprises, from top to bottom, a protective layer, a display layer, a diffuse reflection layer, and a light source layer. The imaging process can be simply described as follows: the light source layer emits visible light, which is then uniformly dispersed by the diffuse reflection layer. The liquid crystal TFTs and color filters in the display layer filter the visible light according to the input signal. Finally, the visible light passing through the polarizer forms the image seen by the operator. The diffuse reflection layer is also known as the color filter layer.

[0075] Specifically, the light source layer includes a main control board, a back panel, a backlight, and a frame. The display principle of an LCD relies on liquid crystals to block light components to control brightness. A light source is necessary to see an image on the screen, so the backlight is responsible for providing the most basic light source for the LCD screen display.

[0076] Reference Figure 8-9The display layer, from top to bottom, includes a horizontal polarizer, a color filter, liquid crystal, a TFT glass, and a vertical polarizer. The light emitted from the backlight panel is not directional and radiates outwards. If such light passes through the twisting of the liquid crystal molecules, the naked eye may see a blank white screen or a patch of red, green, and blue mixed colors, making it impossible to see a normal image. The vertical polarizer is used to standardize the direction of the light before it is sent to the liquid crystal layer. The liquid crystal is twisted under the control of the TFT to control the illumination of the directional light, thereby changing the brightness of the light leading to the subsequent pixel units. The liquid crystal itself has no color; color comes from the color filters. The color displayed by each liquid crystal sub-pixel in the liquid crystal screen depends on the color filter, not the sub-pixel itself. The backlight emits white light, which passes through various color filters. The light of the corresponding color behind the filter is then emitted. Therefore, in a liquid crystal display, the function of the color filter is to add color, corresponding to the function of phosphors in a CRT monitor. Liquid crystal subpixels adjust grayscale by controlling the intensity of light passing through them. A few active matrix displays use analog signal control, while most use digital signal control technology. Most digitally controlled LCDs use 8-bit controllers (some use 10-bit controllers), capable of producing 256 grayscale levels. Each subpixel can represent 256 levels, resulting in 256 × 3 colors, or 16,777,216 colors per pixel, commonly referred to as 16,777,216 colors. Because the human eye's perception of brightness is not linear, and the eye is more sensitive to changes in low brightness, this 24-bit color depth is sufficient to meet ideal requirements. Light rays that were originally aligned become misaligned after being twisted by the liquid crystal layer. If the diffused light is not re-normalized, what is seen on the screen remains a blank white image, as the twisted light is not reflected. A polarizer orthogonal to the polarization direction of the lower polarizer is used to re-deflect the light center after it has been twisted by the liquid crystal. Light rays at different angles have different brightness levels after passing through the upper polarizer, resulting in an alternating bright and dark image on the screen. Because the deflected light is colored light that has passed through a color filter, a color image visible to the naked eye is displayed on the screen.

[0077] Furthermore, refer to Figure 10Capacitive touchscreen technology works by sensing the electrical current of the human body. A capacitive touchscreen is a four-layer composite glass screen. The inner surface and interlayer of the glass screen are each coated with a layer of indium tin oxide (ITO). The outermost layer is a thin silica glass protective layer. The interlayer ITO coating serves as the working surface, with four electrodes extending from the four corners. The inner ITO layer acts as a shielding layer to ensure a good working environment. When a finger touches the metal layer, due to the human body's electric field, a coupling capacitor is formed between the user and the touchscreen surface. For high-frequency currents, the capacitor is a direct conductor, so the finger draws a small current from the contact point. This current flows out from the electrodes at the four corners of the touchscreen, and the current flowing through these four electrodes is proportional to the distance from the finger to the corner. The controller determines the position of the touch point by accurately calculating the proportions of these four currents.

[0078] In other embodiments, alternatives include novel display materials such as OLED transparent screens, projectors, laser projectors, and electrochromic materials.

[0079] If this embodiment is selected, it should be noted that a parallel light source must be used as the backlight system; otherwise, problems such as "image distortion, uneven distribution of dark corners, and shadowless lamp effect" may easily occur in image projection, which will seriously affect the defect recognition effect.

[0080] Example 6 Reference Figure 11 As a further improvement based on Embodiment 4, a honeycomb grating is further provided between the diffuse reflection layer and the display layer.

[0081] A honeycomb panel is used to filter diffuse light sources, eliminating side light and creating parallel light to project the electronic patterns on the LCD layer. Actual measurements show clear imaging, with the shadowless lamp effect largely eliminated. However, the honeycomb panel itself blocks some light; when the panel is close to the paper to be sorted, it projects a cross-sectional image onto the paper. This problem can be solved by increasing the distance between the honeycomb panel and the paper, i.e., the slight side light source creates a shadowless lamp effect on the panel itself, thus eliminating the shadow. Simultaneously, because the LCD layer is close to the paper being sorted, the shadowless lamp effect is negligible under small-angle quasi-parallel light illumination.

[0082] In this embodiment, because the honeycomb panel uses a filtering method to select the light angle, it actually severely blocks the light source, resulting in a significant decrease in the actual illuminance projected onto the paper. Measurements show that the original large-area LED array with a light transmittance of 6000 lumens, after filtering, only achieves an actual brightness of 90-120 lumens after passing through the paper, barely meeting the paper selection requirements. To fully meet the paper selection requirements, it is estimated that the brightness of the backlight LED matrix needs to be increased to over 8000 lumens.

[0083] This embodiment can also be used in embodiments one through three or other embodiments that require the parallelism of the light source.

[0084] Example 7 Reference Figure 13 As a further improvement based on Embodiment 4, the light source layer includes several light-shielding plates corresponding to the boundaries of each area on the banknote paper. The light-shielding plates divide the light source layer into several illumination units, and each illumination unit is provided with an LED point light source; the filter layer is a Fresnel lens.

[0085] A Fresnel lens is essentially a convex lens, but its thinness and light weight make it ideal for installation inside light boxes. By using a Fresnel lens array in conjunction with multiple LED point light sources to achieve parallel light source illumination of the product, the effect is excellent, with a brightness of 170 lumens through the paper and a clear image.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A banknote paper quality verification operating system, control method, and recording method, characterized in that, include: The paper storage compartment is for inspection, the inspection platform is for inspection, and the paper storage compartment is for completed inspection. The paper storage compartment contains banknotes that have been preliminarily inspected and identified by the preceding equipment. The testing platform includes: The operating surface is a light-transmitting transparent layer made of a transparent material; An image vision module is disposed on the lower surface of the operating plane. The image vision module forms a banknote pattern projection at the contact surface with the operating plane, and the image vision module emits parallel visible light from bottom to top. The identification module is arranged at intervals directly above the operating plane, and the identification module is used to identify the identity code of the banknote; The control module acquires the identity code identified by the identification module, retrieves invalidation matrix data from the data table, highlights the invalidation open position background based on the invalidation matrix data, manually checks the highlighted area, and records the defective area after the manual check is completed.

2. The banknote paper quality verification operating system as described in claim 1, characterized in that, The inspection platform also includes an operating system, which is used to receive inspection information directly input by humans, and to re-mark the defective areas of the paper to be inspected or cancel the marking of defective areas that were misidentified in the preceding equipment based on the inspection information. The display module is located on the inspection platform at a position that is offset from the operation platform, the image vision module, and the recognition module. The display module is used to display the identification code of the paper.

3. The banknote paper quality verification operating system as described in claim 2, characterized in that, The image vision module includes a light source layer that emits visible light from bottom to top, a filter layer above the light source layer, and a display layer above the filter layer.

4. The banknote paper quality verification operating system as described in claim 3, characterized in that, The light source layer is an LED matrix, and the filter layer includes a diffuse reflector plate disposed above the light source layer and a honeycomb grating disposed above the diffuse reflector plate.

5. The banknote paper quality verification operating system as described in claim 3, characterized in that, The light source layer includes several light-shielding plates corresponding to the boundaries of each area on the banknote paper. The light-shielding plates divide the light source layer into several lighting units, and each lighting unit is provided with an LED point light source. The filter layer is a Fresnel lens.

6. The banknote paper quality verification operating system as described in claim 1, characterized in that, The intensity of the visible light emitted by the visual module after passing through the paper is 150~350lm, and the visible light is cool-colored light.

7. The banknote paper quality verification operating system as described in claim 1, characterized in that, The paper output direction of the paper tray to be inspected, the paper feed direction of the inspection platform, the paper output direction of the inspection platform, and the paper feed direction of the paper tray to be inspected are multiple tangents of the same arc, and the angle between the paper output direction of the paper tray to be inspected and the paper feed direction of the paper tray to be inspected is 5~20°.

8. A control method for a banknote paper quality verification operating system, characterized in that, An operating system for quality verification of banknote paper as described in any one of claims 1-7 includes the following steps: S1. The banknotes in the paper compartment to be inspected are manually removed and placed on the operating surface and aligned. S2. The identification module obtains the identity code of the banknote and retrieves its invalidation matrix data from the data table Data_Piece. If the converted value of the matrix is ​​not 0, the invalidation opening information is calculated and the background drawing of the known invalidation opening is highlighted. S3. Manual inspection: The highlighted areas are manually inspected. If the highlighted areas are indeed defective, the staff will click the "Single Opening Cancel" button and select the highlighted areas. Otherwise, they will select the "Single Opening Mark Good" button and select the highlighted areas. The canceled areas will be marked with a red box by the image vision module. S4. Manual inspection: Staff will screen the non-highlighted areas based on the overlap information between the projected pattern and the banknote paper pattern. If a defect is found in one of the open areas, click the "Single Opening Cancelled" button and select the corresponding area. The cancelled area will be marked with a red box by the image vision module. S5. After a single banknote is verified, the staff clicks the "Complete Inspection" button, and the control module collects the corresponding invalid area information and updates it to a new data table for storage.

9. A method for recording defective paper in a banknote paper quality confirmation operating system, characterized in that, The operating system for quality verification of banknote paper as described in any one of claims 1-7 is characterized by the following steps: The initial detection and identification by the preceding equipment is completed, and the method for recording the location of defects on a single sheet of paper uses a binary matrix identifier for compressed storage to derive a rejection matrix. The specific algorithm includes the following steps: A1. Mark the banknote opening position matrix, with the top right of the front as the first opening, and add them one by one from top to bottom and from right to left; A2. Use binary 0 and 1 to indicate whether the current ticket is invalid; A3. The nth root corresponds to 2n-1 binary bits; A4. The XOR function can be used on binary sequences to determine whether a specified open bit is invalid.

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