CN1787018A - Optical recognition device and method - Google Patents

Abstract

An optical recognition device for recognizing special-purpose paper, such as paper money. The optical recognition device comprises at least one light source, at least one light splitting device, at least two optical detectors and an image recognition circuit; the light splitting device divides the light generated by the corresponding light source into two main light beams, and the two main light beams are projected on the paper to be detected to form more than two response images; the optical detector receives the response images, and the image recognition circuit analyzes the response images to recognize the authenticity and the type of the paper.

Description

Optical recognition device and method

technical field

The invention relates to an optical identification device and method, in particular to an optical device and method for testing special paper.

Background technique

Due to the advancement of electronic technology and the increase of labor costs, more and more tasks are performed by automatic machines, such as various vending machines, money changers and so on. Initially, automatic machines mainly used low-denomination coins, and often used volume, density, conductivity and other characteristics to identify the authenticity of coins. However, as there are more and more high-value applications of automatic machines, high-value banknotes will inevitably become objects that automatic machines must handle.

However, whether it is to identify the amount or the authenticity, the difficulty of banknote identification is often higher than that of coins. Therefore, many people propose various methods for identifying the authenticity and denomination of banknotes. For example, magnetic ink lines of special materials are added to banknotes, and the denomination or authenticity of banknotes can be detected through magnetic identification.

Of course, optical recognition is the most direct method, however, optical recognition is also the most difficult. Because most image recognition programs often involve complex algorithms, if this makes the recognition mechanism expensive, it will be difficult to popularize because of the high cost.

In fact, in addition to banknotes, various special-purpose papers such as identification certificates and various securities have similar difficulties to be solved.

Generally speaking, it will be a very important work if a device and method can be proposed to achieve the identification of special paper in an effective and low-cost manner.

Contents of the invention

Therefore, one object of the present invention is to provide an effective and cost-effective optical identification device and method.

According to an embodiment of the present invention, an optical identification device is provided for identifying special-purpose paper, such as banknotes.

The optical identification device has at least one light source, at least one light splitting device, at least two optical detectors, and an image identification circuit. Each light source has a corresponding spectroscopic device, which divides the light emitted by the light source into two main beams to project on the paper to be tested, thereby generating two corresponding response images. The optical detector receives the two response images, and sends these response images to the image recognition circuit for recognition.

The spectroscopic device can be composed of one or more prisms. In addition, in order to make the light of the light source more densely projected on the surface of the paper to be tested, and to make the response image appear more clearly on the optical detector, one or more prisms can be used. A lens is placed in the direction of the light to focus the light.

In addition, the light source, light splitting device and lens described here can be made into modules to speed up the required construction period and reduce the cost.

Therefore, the present invention has at least the following advantages:

First, in the present invention, only one light source is needed to supply two optical detectors to detect two different areas, reducing the component cost. Secondly, the light source, spectroscopic device and lens can be prefabricated into modules to speed up the time required for construction. In addition, due to the small number of components required, more optical detectors can be placed in a limited space, increasing the scanning range and sampling number of the paper to be tested, which is of great help to increase the recognition rate of the paper.

Description of drawings

Fig. 1 (a) is a schematic diagram according to an embodiment of the present invention;

Fig. 1 (b) is the schematic diagram according to moving the paper to be tested;

Fig. 2 is a schematic diagram according to a preferred embodiment of the present invention;

FIG. 3 is an exploded view of components according to a preferred embodiment of the present invention;

Figure 4(a) is a schematic diagram of some components of the optical module;

Figure 4(b) is a schematic diagram of some components of the optical module;

Figure 4(c) is a schematic diagram of some components of the optical module;

Fig. 5 is an operation diagram of some components of the optical module;

Fig. 6 is a relationship diagram between another lens and an optical module;

FIG. 7 is a flowchart according to an embodiment of the present invention.

Explanation of reference signs

10 Optical identification device 102 Light source

104 Spectroscopic device 106 Optical detector

108 Image recognition circuit 11 Paper

112 track 114 track

120 light 122 light

124 light 126 light

128 Light 13 Inspection area

14 Predetermined direction 20 Optical identification device

201 Upper case 202 Circuit board

2031 Optical module 2041-2046 Light source

2051-2054 Optical detector 2061-2066 Prism

2081-2088 Lens 21 Paper

231 Inspection Area 24 Scheduled Direction

Detailed ways

Please refer to FIG. 1( a ), which is a correlation diagram of some components of the optical identification device 10 . The optical identification device 10 is used to identify special-purpose paper 11 , such as banknotes, identification cards, checks or various securities. The optical recognition device 10 has a light source 102 , a spectroscopic device 104 corresponding to the light source 102 , two optical detectors 106 , and an image recognition circuit 108 .

The light source 102 emits visible or invisible light 120 , and the light 120 is split into two main beams 122 , 124 by the beam splitter 104 . When the paper 11 moves through the inspection zone in a predetermined direction, the two main beams illuminate the area of the paper 11 that passes through the inspection zone and generate responsive images 126, 128, respectively. The two optical detectors 106, such as CCD or CMOS image capture circuit, respectively receive the response images 126, 128, and send the received response images 126, 128 to the image recognition circuit 108 for processing to complete the recognition work.

Please refer to FIG. 1( b ), which is a schematic diagram of when the paper 11 moves through the inspection area 13 in a predetermined direction 14 . Since the paper 11 continues to move in the predetermined direction 14 during the recognition process, the data read by the optical detector 106 are two tracks 112 , 114 on the paper 11 . In other words, in this embodiment, only one light source can be used to read the two test tracks 112 , 114 on the paper 11 , and the structure is simple and low cost.

A preferred embodiment will be used below to further illustrate the features and implementation of the present application.

Please refer to FIG. 2 , which is an embodiment of further implementation of the above concept. The optical identification device 20 can be installed in various automatic machines, such as automatic vending machines, currency exchange machines, counterfeit banknote identification machines, and the like. When the optical identification device 20 is installed in an automatic machine, the paper 21, such as banknotes, can be pulled by the mechanical device of the automatic machine, such as a belt driven by a stepping motor, and move through the inspection area of the optical identification device 20 repeatedly or non-repeatedly. 231.

Please refer to FIG. 3 , which is an exploded view of the optical identification device 20 . The optical recognition device 20 has an upper housing 201, a circuit board 202, an optical module 2031, light sources 2041-2043, optical detectors 2051-2054, and unmarked image recognition circuits and control circuits in the drawings.

The optical module 2031 has prisms 2061 , 2062 , 2063 respectively corresponding to the light sources 2041 , 2042 , 2043 . In addition, the optical module 2031 also has lenses 2081 , 2082 , 2083 , and 2084 respectively corresponding to the optical identifiers 2051 , 2052 , 2053 , and 2054 . Through the base, the optical module 2031 can be placed on the circuit board 202 .

The optical module 2031 is composed of several components with the same structure, and the components with the same structure and their relationship are described as follows.

Please refer to FIG. 4( a )-( c ), which are schematic diagrams of some components in the optical module 2031 . Continuing with FIG. 3 and related descriptions, it can be seen that the prism 2061 corresponds to the light source 2041 , and the lenses 2081 and 2082 respectively correspond to the optical detectors 2051 and 2052 . Fig. 4 (a) provides the perspective view of observing lens 2081, 2082 with a specific direction, and Fig. 4 (b) then provides the perspective view of viewing lens 2081, 2082 and prism 2061 in another direction, as Fig. 4 (c) then provides the side view view. Therefore, through Fig. 4(a)-(c), it should be possible to understand the structure and mutual relationship of the lenses 2081, 2082, 2061 in this embodiment. As for the other lenses 2083-2084 and prisms 2062-2063 in the optical module 2031, they are respectively the same as the lens 2081-2082 and the prism 2061 described above. The structure of the optical identification device 20 can be understood only by referring to FIG. 3 . This will not be repeated here. In addition, the lens structures mentioned here can all be integrally formed from materials such as light-transmitting plastics.

Next, please refer to FIG. 5 , which shows how the lenses 2081 , 2082 and the prism 2061 cooperate with the light source 2041 and the optical detectors 2051 , 2052 .

When in use, the light emitted by the light source 2041 is divided into two main light beams by the prism 2061 and then projected onto the part of the paper 21 to be moved through the inspection area 231 . Due to this projection, the two corresponding images generated respectively are focused on the optical detectors 2051, 2052 through the lenses 2081, 2082, respectively. The optical detectors 2051, 2052 are connected to an image recognition circuit (not shown in the figure), so that the image recognition circuit interprets the information of the paper 21 to identify the authenticity or denomination of the paper.

Please refer to FIG. 6 , which is a schematic view of adding another lens to the optical identification device 20 . In order to further focus the light emitted by the light sources 2041-2043 on the paper 21 to be tested to achieve better image quality, one or more lenses may also be added to focus the light. For example, as shown in FIG. 6 , a lens 2311 is added above the optical module 2031 . The lens 2311 can be mounted on the inspection area 231 of the upper casing 201 , with its plane facing the paper 21 . In this way, a focusing effect can also be produced on the response image.

In addition, since the lenses 2081-2084 are respectively arranged alternately with the prisms 2061-2063. In practice, each light source 2041-2043 is used by two of the optical detectors 2051-2054 at the same time. In addition, except the outermost optical detectors 2051 , 2054 , other optical detectors 2052 , 2053 can also respectively receive the response images projected onto the paper 21 by the light from the two light sources. At this time, the lighting sequence of the light sources 2041-2043 is controlled by the control circuit (not shown in the figure), and the image recognition circuit also uses this lighting sequence for identification, so many different combinations can be used to obtain the paper for different light sources. Response results, and then make the recognition results more accurate.

Moreover, since the response images of the paper to different light sources are different, more information about the paper 21 to be tested can be obtained by adjusting and setting the light source. For example, in the application of detecting banknotes such as New Taiwan dollars, it is known from the experimental results that the following light source configurations will be able to obtain quite accurate test results. As shown in Figure 3, the light sources 2041, 2043 are arranged to emit light-emitting diodes (LEDs) that can emit orange light, the light source 2042 is arranged to emit light-emitting diodes for invisible light, the light source 2044 is arranged for red light-emitting diodes, and the light source 2043 is also arranged to emit invisible light. diode. The invisible light mentioned here refers to invisible light such as infrared light or ultraviolet light.

Please refer to FIG. 7 , which further illustrates the implementation method of the present invention by means of a flow chart. Firstly, the paper to be side is moved across a recognition area in a predetermined direction (step 702). Next, a light source is used to generate light of at least a predetermined wavelength (step 704). Using a spectroscopic device to split the light generated by the light source into at least two main beams for projecting onto the paper to be tested (step 706 ). Next, collect and identify the response images generated by the paper to be tested projected by the two main light beams (step 708 ).

Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person familiar with the art can make various changes and modifications without departing from the creative idea and scope of the present invention. Therefore, the protection scope of the present invention should be defined by the claims.

Claims (19)

1. An optical identification device for identifying a special-purpose paper that moves through an inspection area in a predetermined direction, the optical detection device comprising: at least one light source; At least one spectroscopic device, wherein each of the above-mentioned light sources corresponds to a spectroscopic device, and each spectroscopic device is responsible for dividing the light emitted by the corresponding light source into two main beams, and the two main beams are irradiated when the paper moves through the inspection area Area; At least two optical detectors, wherein a corresponding optical detector is installed on both sides of each light source, and the optical detector receives at least two responses returned by the corresponding two main beams irradiated on the inspection area of the paper images; and An image recognition circuit, connected to the at least two optical detectors, is used to receive the at least two responsive images to identify the content of the paper. 2 . The optical identification device according to claim 1 , further comprising a first lens, the two light beams pass through the first lens before being transmitted to the identification area, so as to gather the two light beams. 3. The optical identification device according to claim 1, wherein the light splitting device comprises at least one prism, through which the light emitted by the light source is split into two corresponding beams. 4. The optical identification device according to claim 1, further comprising at least two second lenses, each optical detector has a corresponding second lens, and the second lens is responsible for focusing the response image on the corresponding on the optical detector. 5. The optical recognition device according to claim 1, further comprising a printed circuit board, which is used to carry the image recognition circuit, at least one light source and at least two optical detectors, and also comprises A base, the base carries the at least two second lenses, and the base is placed on the printed circuit board. 6. The optical identification device according to claim 4, wherein the at least two second lenses are integrally formed of light-transmitting plastic material. 7. The optical identification device as claimed in claim 2, further comprising a casing, the casing is used to install the first lens and is disposed on the printed circuit board. 8 . The optical recognition device according to claim 1 , further comprising a control circuit for controlling a lighting sequence of the at least one light source, and the image recognition circuit interprets the corresponding image according to the lighting sequence. 9. The optical identification device according to claim 1, wherein the special-purpose paper is a banknote, and the number of the at least one light source is three, which are respectively a first light source, a second light source and A third light source, wherein the first light source, the second light source and the third light source are arranged in a row, and the first light source and the third light source are respectively arranged with an orange light-emitting diode, and the second light source is arranged with an invisible light-emitting diode , the third light source is also arranged an invisible light emitting diode. 10. An optical identification method for identifying a special-purpose paper, the method comprising: moving the special purpose paper across a recognition zone in a predetermined direction; using at least one light source to generate light of at least one predetermined wavelength; Using at least one spectroscopic device to divide the light generated by the at least one light source into two beams and project them onto the identification area, so that the two beams respectively generate at least two responsive images for special-purpose paper, wherein each of the spectroscopic devices corresponds to one of the light sources; receiving the at least two responsive images using at least two optical detectors; and The response images received by the at least two optical detectors are analyzed to identify the special purpose paper. 11. The method according to claim 10, further comprising using a first lens, the two light beams pass through the first lens before being transmitted to the identification area, so as to gather the two light beams. 12. The method according to claim 10, wherein the light splitting device comprises at least one prism, and the light emitted by the light source is split into two corresponding beams through the prism. 13. The method of claim 10, further comprising using at least two second lenses, each optical detector having a corresponding second lens, the second lens being responsible for focusing the response image on the corresponding optical detector device. 14. The method according to claim 13, further comprising providing a printed circuit board for carrying the image recognition circuit, at least one light source and at least two optical detectors, and further comprising providing A base, the base carries the at least two second lenses, and the base is placed on the printed circuit board. 15. The method according to claim 13, wherein the at least two second lenses are integrally formed of light-transmitting plastic material. 16. The method of claim 11, further comprising providing a housing for mounting the first lens, and the housing is disposed on the printed circuit board. 17. The method according to claim 10, further comprising providing a control circuit for controlling a lighting sequence of the at least one light source, and the image recognition circuit interprets the corresponding image according to the lighting sequence. 18. The method according to claim 10, wherein the special-purpose paper is a banknote, and the number of the at least one light source is three, which are respectively a first light source, a second light source and A third light source, wherein the first light source, the second light source and the third light source are arranged in the same row, and the first light source and the third light source are respectively arranged with an orange light-emitting diode, and the second light source is arranged with an invisible light-emitting diode , the third light source is also arranged an invisible light emitting diode. 19. A method of identifying banknotes, the method comprising: moving a banknote in a predetermined direction through an inspection zone; Use at least three light sources to irradiate the banknote in the inspection area, wherein the at least three light sources are respectively a first light source, a second light source and a third light source, and wherein the first light source, the second light source and the third light source Arranged in the same column, and the first light source and the third light source are respectively arranged with an orange light-emitting diode, the second light source is arranged with an invisible light-emitting diode, and the third light source is further arranged with an invisible light-emitting diode; Response images of the at least three light sources irradiated on the banknote are collected to identify the banknote.

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