JP2005196627A - Camera with false ticket detecting function and false ticket detecting method using camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily determine correctness of paper sheets without being restricted by a place. <P>SOLUTION: An ultraviolet transmissive filter 16 is rotatably installed in front of a light emitting surface of a flash part 13 with a shaft 17 as the center. When irradiating only the ultraviolet light to an object, the ultraviolet transmissive filter 16 is moved to a position (a position indicated in the figure (C)) for shielding the light emitting surface of the flash part 13. When irradiating the visible light to the object in ordinary photographing, the ultraviolet transmissive filter 16 is retreated to a position (a position indicated in the figure (B)) of not shielding the light emitting surface of te flash part 13. A fluorescent image of cutting the visible light by the ultraviolet transmissive filter 16 is photographed, and the correctness of the paper sheets is determined by its fluorescent image. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a camera with a counterfeit ticket detection function and a counterfeit ticket detection method thereof.

In paper sheets such as banknotes and securities, printing that shows a fluorescence reaction of a predetermined color is performed when ultraviolet rays are irradiated to prevent counterfeiting. In the past, in order to easily check whether the bill is a fake note, a commercially available ultraviolet lamp was irradiated on the paper sheet, and the presence or absence of a fluorescent reaction was visually confirmed.
However, it is difficult to detect a counterfeit such as a fluorescent paint applied by such a method of judging by human eyes.

In order to solve the above problems, for example, in Patent Document 1, a document is irradiated with a plurality of types of light having different wavelengths, and an image is captured and compared with a captured image of a real document that has been captured in advance. A document collating apparatus for determining authenticity by doing so is described.
JP 2001-76203 A (FIG. 1, FIG. 3, paragraph 0016, paragraph 0020)

The invention described in Patent Document 1 is used to determine authenticity by irradiating a document such as a license or identity lighting presented by a customer with visible light and infrared light in an automatic contract machine. It is not possible to judge the authenticity of documents.
An object of the present invention is to make it possible to easily determine the authenticity of paper sheets such as banknotes and securities in retail stores, taxis and the like.

  A camera with a counterfeit bill detection function according to the present invention is a camera having a flash unit and an imaging unit that illuminates a subject by emitting light from the flash unit, and the flash unit shields the light emitting surface. Alternatively, the camera has an ultraviolet transmission filter that can be moved to a retracted position, and the camera issues a release instruction when a shooting mode setting unit that sets a shooting mode of the camera and a false bill detection mode is set by the shooting mode setting unit. In response, an ultraviolet transmission filter moving unit that moves the ultraviolet transmission filter to a position that shields the light emitting surface of the flash unit, and after the ultraviolet transmission filter has moved to the shielding position, the imaging unit moves the paper sheet A fluorescent image is obtained by imaging with flash irradiation.

  According to the present invention, it is possible to determine the authenticity of a paper sheet from the fluorescence image by irradiating the paper sheet with flash light transmitted through the ultraviolet transmission filter and capturing a fluorescent image. As a result, it is possible to detect a counterfeit ticket using a portable camera, so it is possible to easily determine the authenticity of a paper sheet at a retail store, a taxi, or the like.

  Another camera with a counterfeit bill detection function according to the present invention is a camera having a flash unit and an imaging unit that emits light from the flash unit and irradiates a subject to perform imaging. An infrared transmission filter that can be moved to a shielded or retracted position, and the camera has a release mode when a shooting mode setting unit that sets a shooting mode of the camera and a false bill detection mode is set by the shooting mode setting unit. In response to the instruction, an infrared transmission filter moving unit that moves the infrared transmission filter to a position that shields the imaging surface of the imaging unit; and after the infrared transmission filter has moved to a shielding position, the imaging unit An infrared image is obtained by taking an image of a paper sheet by flash irradiation.

According to the present invention, an infrared image of a paper sheet can be captured by the camera, and the authenticity of the paper sheet can be determined based on the infrared image. As a result, it is possible to detect a counterfeit ticket using a portable camera, so it is possible to easily determine the authenticity of a paper sheet at a retail store, a taxi, or the like.
In the above-described invention, there is further provided authenticity determination means for determining whether or not the paper sheet is a genuine note or a fake note based on the obtained fluorescent image or infrared image.

With this configuration, since the authenticity determination unit of the camera determines whether or not it is a fake note based on the captured fluorescent image or infrared image, the user only images the paper sheet with the camera. You can find out if the paper is genuine or counterfeit.
In the above invention, when visually determining whether the paper sheet is a genuine note or a fake note, the R, G, B images of the fluorescent image are switched and displayed.

By configuring in this way, it is possible to switch between a fluorescent image consisting of R pixels, a fluorescent image consisting of G pixels, and a fluorescent image consisting of B pixels, so that it can be visually checked whether it is genuine or counterfeit. Can be determined.
In the above invention, when it is visually determined whether the paper sheet is a genuine note or a fake note, the infrared image is displayed for the determination.

By comprising in this way, the displayed infrared image can be confirmed visually and it can be judged whether it is a genuine note or a fake note.
In the above invention, the camera performs flash photography with the ultraviolet transmission filter retracted prior to flash photography in a state where the ultraviolet transmission filter shields the light emitting surface of the flash unit according to a release instruction. To obtain a visible image.

With this configuration, it is possible to determine in advance whether or not the photographing position of the paper sheet is appropriate based on the photographed visible image, so it is possible to efficiently determine whether the paper sheet is true or false.
In the above invention, according to the release instruction, the camera may perform a flash operation in a state in which the infrared transmission filter is retracted prior to flash photography in a state where the infrared transmission filter shields the imaging surface of the imaging unit. Take a picture and obtain a visible image.

With this configuration, it is possible to determine in advance whether or not the photographing position of the paper sheet is appropriate from the photographed visible image, so that the authenticity determination can be performed more efficiently.
In the above invention, it further includes a paper sheet position correcting means for correcting the position of the fluorescent image or the infrared image based on the obtained visible image.

With this configuration, the position of the fluorescent image or the infrared image can be corrected based on the position of the visible image. For example, the fluorescent image or the infrared image is used as a reference image as a reference for authenticity determination. The determination accuracy can be increased by matching the position.
In the above invention, the acquired image position appropriateness determining means for determining whether or not the acquired image after the position correction by the paper sheet position correcting means is appropriate, and the acquired image position appropriateness determining means, Warning means for giving a warning when it is determined that the position of the acquired image is inappropriate is further provided.

With this configuration, when it is determined that the position of the acquired image of the paper sheet is inappropriate for determining authenticity, a warning is issued, so the user can change the shooting position to You can shoot a good image.
In the above invention, there is a warning means for giving a warning when there is no paper sheet within a predetermined distance range according to the distance measurement result at the time of release.

With such a configuration, a warning is issued when an attempt is made to capture images in a state of being separated by a predetermined distance or more, so that the user can capture a fluorescent image or an infrared image of a paper sheet at an appropriate distance.
In the above-mentioned invention, when the warning is given, it further includes a prohibiting means for prohibiting photographing.

With such a configuration, when the shooting distance is not appropriate, shooting is prohibited, so that useless determination processing can be prevented.
In the above invention, the counterfeit ticket detection mode includes a currency or other selection menu, and can select either currency or other securities, and the determination criteria for the authenticity determination are based on the type of the selected paper sheet. Is set.

  With this configuration, when the user selects a currency or a security, a determination criterion according to the type of the selected paper sheet is set, so the currency or the photographed image of the security is determined appropriately. It can be compared with the standard. Thereby, the authenticity determination accuracy of paper sheets can be improved.

In the invention described above, the counterfeit ticket detection mode includes a denomination selection menu, a target denomination can be selected, and a criterion for the authenticity determination is set according to the denomination of the selected paper sheet. Is set.
By configuring in this way, by selecting a currency denomination, a determination criterion according to the selected denomination is set, so that the accuracy of currency determination can be further increased.

In the above invention, the fake ticket detection mode has a front / back selection menu, the front / back of the target paper sheet can be selected, and the determination criterion for the authenticity determination according to the front / back of the selected paper sheet Is set.
With this configuration, the authenticity of the paper sheet can be determined based on an appropriate determination criterion by selecting whether the photographed surface is the front or back side of the paper sheet. The determination accuracy can be improved.

In the above invention, the authenticity determination means determines authenticity by comparing the luminance value or the ratio of luminance values of the R, G, and B images of the fluorescent image with a reference value. Further, the authenticity determination means determines authenticity based on the luminance values of the infrared light absorbing portion and the non-absorbing portion in the infrared image.
With this configuration, it is possible to more accurately determine the authenticity of the paper sheet.

  According to the present invention, the authenticity of a paper sheet can be easily determined using an image photographed by a camera. Moreover, since it is built in the camera, it can be used freely anywhere. Further, the authenticity of the paper sheet can be determined with a low-cost apparatus.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is an external view of the camera 11 according to the embodiment of the present invention. FIGS. 1B and 1C are ultraviolet rays that set the light emitting surface of the flash unit 13 in a shielding state or a non-shielding state. FIG. 6 is a diagram illustrating a state of the transmission filter 16.

  As shown in FIG. 1A, the camera 11 has a photographing lens 12 at the center of the front, a flash unit 13 at the upper left of the front, and a photometric sensor 14 above the photographing lens 12. The flash unit 13 includes a Xe lamp or the like. A release button 15 is provided on the upper left side of the camera 11.

  As shown in FIGS. 1B and 1C, an ultraviolet transmission filter 16 is attached in front of the light emitting surface of the flash unit 13 so as to be rotatable about a shaft 17. When the subject is irradiated only with ultraviolet light, the ultraviolet transmission filter 16 moves to a position where it shields the light emitting surface of the flash unit 13 (position shown in FIG. 1C). When irradiating the subject with visible light during normal photographing, the ultraviolet transmission filter 16 moves to a position retracted from the light emitting surface of the flash unit 13 (position shown in FIG. 1B). Note that the ultraviolet transmission filter 16 is moved by a motor of an ultraviolet filter driving unit described later.

FIG. 2 is a diagram showing the structure of the optical system inside the camera 11. Light incident from the photographic lens 12 passes through the diaphragm 21 and the infrared cut filter 22 or the infrared transmission filter 23, passes through the lens 25, and is received by the image sensor 26 made up of a CCD or the like.
The infrared cut filter 22 is a filter having a characteristic of cutting infrared light and transmitting visible light, and the infrared transmission filter 23 is a filter having a characteristic of transmitting infrared light and cutting visible light. The filters are integrally attached to the filter plate 24.

The rotation angle of the filter plate 24 is controlled by the motor 27 so that the infrared cut filter 22 is located at a position where the imaging surface is shielded during normal imaging, and when the infrared image is captured, the infrared transmission filter 23 is controlled by the imaging surface. The rotation angle is controlled so as to come to a position where the light is shielded.
Here, the filter characteristics of the ultraviolet transmission filter 16 and the infrared transmission filter 23 will be described with reference to FIGS. 3A and 3B and FIG.

3A is a diagram illustrating the filter characteristics of the ultraviolet transmission filter 16, FIG. 4 is a diagram illustrating the filter characteristics of the infrared transmission filter 23, and FIG. 3B is a strobe light emission window. It is a figure which shows the spectral-intensity characteristic according to material.
3A and 4, the vertical axis represents light transmittance (%), and the horizontal axis represents wavelength (nm). In FIG. 3B, the vertical axis represents the light emission intensity (μw / cm ² · nm), and the horizontal axis represents the wavelength (nm).

  In FIG. 3 (B), the characteristic that the radiation intensity is large at a wavelength of 300 nm or less shows the characteristic when synthetic quartz glass is used for the strobe radiation window (shown by the solid line in FIG. 3 (B)). The characteristic in which intensity | strength is reducing significantly has shown the characteristic at the time of using a silicic acid silicate glass, and the characteristic which has decreased in 200 nm vicinity has shown the characteristic of UV glass. In the present embodiment, the emission window of the flash unit 13 uses synthetic quartz glass.

As shown in FIG. 3A, the ultraviolet transmission filter 16 has a characteristic of blocking light having a wavelength of 400 nm or more and transmitting ultraviolet light having a wavelength of less than 400 nm.
Accordingly, when the light emitting surface of the flash unit 13 is shielded by the ultraviolet transmission filter 16, only the ultraviolet light having a wavelength of 400 nm or less is irradiated to the subject.

As shown in FIG. 4, the infrared transmission filter 23 has a characteristic of blocking light having a wavelength of about 720 nm or less and transmitting infrared light having a wavelength longer than that.
Next, FIG. 5 is a block diagram showing an optical system and circuit configuration of the camera 11. In FIG. 5, the zoom lens system 31 includes the photographing lens 12, the diaphragm 21, the infrared cut filter 22 and the like shown in FIG. The lens driving unit 32 moves the lens based on the control of the lens driving control circuit 33.

The imaging element 26 converts the light that has passed through the zoom lens system 31 into an electrical signal and outputs the electrical signal to the imaging circuit 34. The imaging circuit 34 performs processing for reducing noise in the output signal of the imaging device 26, AGC (automatic gain control) processing for controlling gain according to the signal level, and the like.
The A / D conversion circuit 35 converts the analog image signal output from the imaging circuit 34 into digital image data and outputs the digital image data to the data bus 36. The image data output to the data bus 36 is stored in a RAM 37 composed of a DRAM or the like.

The JPEG / MPEG compression / decompression processing unit 38 performs processing for compressing or decompressing image data by the JPEG (Joint Photographic Experts Group) method and processing for decompressing the image data by the MPEG (Moving Picture Experts Group) method.
The control unit 39 executes processes such as image processing, lens drive control, and ultraviolet transmission filter 16 drive control in accordance with a control program stored in the ROM 40.

The ultraviolet filter drive control circuit 41 drives the ultraviolet filter drive unit 42 composed of a motor and a drive mechanism so that the ultraviolet transmission filter 16 is shielded from the light emission surface of the flash unit 13 or the light emission surface of the flash unit 13. Move to a retracted position that does not shield.
The infrared (IR) filter drive control circuit 43 drives an infrared (IR) filter drive unit 44 including a motor and a drive mechanism so that the infrared cut filter 22 or the infrared transmission filter 23 is placed on the optical path of the photographing lens 12. Move.

The video encoder 45 outputs the captured image data or the image data stored in the RAM 37 to the LCD driver 46 and causes the liquid crystal display unit (LCD) 47 to display the image data. Further, the video encoder 45 outputs the image data to the video out terminal 48.
The liquid crystal display unit 47 displays a captured image in the normal shooting mode, and in the fake note detection mode, R, G, and B images of a fluorescent image of a paper sheet, an infrared image, a true / false determination result, and the like. Is displayed.

  The operation unit 49 includes a release button 15, a mode switching button for switching a shooting mode (not shown), a display button for displaying a captured image, and the like. The operation states of the various buttons of the operation unit 49 are detected by the control unit 39, and corresponding processing is executed by the control unit 39.

The strobe light emitting unit 13 is the flash unit 13 described above. The power supply unit 50 supplies a power supply voltage to each part of the motor and the circuit. The power supply unit 50 has an external power supply input terminal 51 and can also supply power from an external power supply.
Next, in the camera 11 having the above-described configuration, the processing content of the bill mode (counterfeit detection mode) for capturing a fluorescent image and an infrared image of paper sheets (banknotes, securities, etc.) is shown in the flowchart of FIG. The description will be given with reference. The following processing is executed by the control unit 11 of the camera 11.

First, a position serving as a guide for photographing a banknote is displayed on the liquid crystal display unit 47 (FIG. 6, S11), and a release wait state is entered (FIG. 6, S12).
FIG. 7 is a diagram illustrating an example in which a recommended banknote position serving as a guide for the shooting position of the subject is displayed. The recommended bill position is displayed in a wavy line on the liquid crystal display unit 47, and the position of the subject paper sheet is displayed on the same screen. From the display, the paper sheet is displayed on the appropriate size and on the appropriate screen. It is possible for the user to determine whether or not shooting is to be performed at the position.

Returning to FIG. 6, when the release button 15 is half-pressed, the distance to the subject is measured (FIG. 6, S13). Whether or not the distance to the subject is appropriate is determined based on whether or not the measured distance to the subject is equal to or less than the upper limit value or the lower limit value of the reference distance (FIG. 6, S14).
If it is determined in step S14 that the subject distance is inappropriate (S14, NO), the process proceeds to step S15, and a message notifying that the banknote position is inappropriate is displayed on the liquid crystal display unit 47. In addition, it is also possible to notify that the bill position is inappropriate by sound means such as a buzzer (not shown).

  FIG. 8A is a diagram illustrating an example of a warning display when the distance to the subject is too far. If the subject is too far away, the message “Subject is too far, please adjust to meet the standard” is displayed on the liquid crystal display 47. Also, the current subject size and recommended banknote position are displayed.

  Next, it is determined whether or not the release prohibition setting is valid (FIG. 6, S16). If the release prohibition setting is valid (S16, YES), the process returns to step S11. If the release prohibition setting is invalid (S16, NO), the process proceeds to step S17. That is, when the release prohibition setting is valid, the processes of steps S11 to S16 are repeated until the distance to the subject becomes appropriate, and when the release prohibition setting is invalid, the user's judgment The shooting distance can be adjusted with to continue shooting.

  If it is determined in step S14 that the subject distance is appropriate (S14, YES), or if the release prohibition setting is invalid (S16, NO), the lens is driven to focus (FIG. 6, S17). In response to the operation of the release button 15, a normal image by visible light is taken (FIG. 6, S18).

If a normal image is acquired, the banknote position correction process of the next step S19 is executed.
Here, with reference to the flowchart of FIG. 9, the content of the banknote position correction process of step S19 of FIG. 6 will be described.
First, the horizontal edge emphasis process of a visible light image is performed (FIG. 9, S41), and the horizontal edge position of a banknote is extracted (FIG. 9, S42).

Next, the vertical edge enhancement processing of the visible light image is executed (FIG. 9, S43), and the vertical edge position of the bill is extracted (FIG. 9, S44).
By these processes, the horizontal edge and the vertical edge of the banknote are extracted.
Next, the intersection of the horizontal edge and the vertical edge of the banknote is calculated, and the coordinates of the vertexes of the four corners of the banknote are calculated (FIG. 9, S45). Furthermore, the inclination of the banknote and the position of the center of gravity are calculated from the coordinates of the four vertices of the banknote, and the magnification for the reference banknote size is calculated from the banknote size (S46 in FIG. 9).

Returning to FIG. 6, if the banknote position correction process of step S19 is completed, it is determined whether or not the acquired image is appropriate in the next step S20.
If it is determined in step S20 that the acquired image is inappropriate (S20, NO), the process proceeds to step S21, and the bill position inappropriate display is performed. In this process, for example, a message indicating that the bill is inappropriate is displayed when the inclination angle of the bill is equal to or greater than a predetermined value.

After the bill position improper display is performed, it is determined whether or not the release prohibition setting is valid (FIG. 6, S22). This process is the same as the process of step S16 described above.
When the acquired image is appropriate (S20, YES) or when the release prohibition setting is invalid (S22, NO), the process proceeds to step S23, and the infrared cut filter 22 on the optical path in front of the image sensor (imager) 26 is obtained. And the infrared transmission filter 23 is moved to a position where the image sensor 26 is shielded.

Next, an infrared image is taken (FIG. 6, S24), and then the infrared transmission filter 23 is retracted, and the infrared cut filter 22 is returned to its original position, that is, on the optical path of the image sensor 26 (FIG. 6). , S25).
An infrared image of a banknote can be taken by the processes in steps S23 to S25.

  Next, the ultraviolet transmission filter 16 is moved to a position where the light emitting surface of the flash unit 13 is shielded (FIG. 6, S26), and a color image (fluorescent image) is taken in that state (FIG. 6, S27). Thereafter, the ultraviolet transmission filter 16 is retracted to a position where the light emitting surface of the flash unit 13 is not shielded (FIG. 6, S28).

The fluorescence image of a banknote can be image | photographed by the process of said step S26-S28.
In the next step S29, the authenticity of the banknote is determined based on the infrared image, and in the next step S30, the authenticity of the banknote is determined based on the fluorescent image.

When the authenticity determination by the infrared image and the fluorescence image is completed, the determination result is displayed on the liquid crystal display unit 47 in the next step S31.
Next, it is determined whether or not the display button (the button of the operation unit 49) is turned on (FIG. 6, S32). When the display button is turned on in the fake ticket detection mode (S32, YES), the process proceeds to step S33. If the determination result is displayed at that time, an infrared image is displayed and an infrared image is displayed. If so, an R image composed of R (red) pixels of the fluorescent image is displayed. If the display button is turned on while displaying the R image, the G image composed of G (green) pixels is displayed, and the display button is turned on while the G image is displayed. When the image is displayed, a B image composed of B (blue) pixels is displayed. Further, when the B button is displayed and the display button is turned on, the authenticity determination result of the banknote is displayed.

  When the display button is not turned on or after step S33, the process proceeds to step S34 to determine whether or not the cancel button (button of the operation unit 49) is turned on. If the cancel button is turned on, the process ends there. When the cancel button is not turned on, the process returns to S32.

Here, the authenticity determination process of the banknote by the infrared image of step S29 of FIG. 6 is demonstrated with reference to the flowchart of FIG.
The infrared image of a banknote is normalized by affine transformation (FIG. 10, S51). Next, the area used for authenticity determination based on the currency type, denomination, and direction of the selected banknote, for example, the area consisting of the infrared absorption part and the infrared absorption part of the banknote is specified. (FIG. 10, S52).

  FIG. 11 is a diagram showing a currency selection screen when performing authenticity determination. Since the currency selection screen displays three types of currencies, Japanese yen, US dollar, and euro, the user selects a currency that is a target of authenticity determination. When the currency is selected, the denomination is displayed next, so the denomination is selected, and whether the direction of the banknote is front or back is selected. When the selection of the currency is completed, a reference value for authenticity determination of the selected currency is read from the memory or the like.

Returning to FIG. 10, next, the luminance value Bno of the infrared image non-absorption portion of the infrared image is calculated (FIG. 10, S53), and the luminance value B of the infrared absorption portion is calculated (FIG. 10, S54).
Further, a reference value Thre for determining the authenticity of the banknote determined by the currency type, denomination and direction of the selected banknote is set (FIG. 10, S55).

It is determined whether or not the ratio Bno / B between the luminance value Bno of the infrared image non-absorption portion and the luminance value B of the infrared absorption portion of the infrared image is larger than the reference value Thre (FIG. 10, S56).
FIG. 12 is a diagram showing a genuine note of paper sheets (such as banknotes) having a portion where infrared light is not absorbed and a copy ticket thereof, and FIG. 12A shows an infrared image of the genuine note. 12 (b) shows an infrared image of the copy ticket.

In the case of the genuine note in FIG. 12A, the left half portion of the rectangular parallelepiped is made so as not to absorb infrared light, so that a white image is obtained and the luminance is increased, and the right half portion receives infrared light. Since it is made to absorb, the brightness is lower than that.
On the other hand, in the case of the copy ticket of FIG. 12B, since the entire rectangular parallelepiped has the same reflection characteristics with respect to infrared light, the luminance and right of the left half portion of the rectangular parallelepiped are obtained as an infrared image. The brightness of the half part becomes equal.

Therefore, in the case of a genuine note, the ratio Bno / B of the luminance value Bon in the portion without infrared absorption and the luminance value B in the portion with absorption is larger than a predetermined reference value Thre. The ratio Bno / B between the luminance value of the non-absorbing portion and the luminance value of the absorbing portion is smaller than the reference value Thre.
If it is determined in step S56 in FIG. 10 that the ratio Bno / B between the luminance value Bon of the non-infrared absorption portion and the luminance value B of the absorption portion is greater than the reference value Thre (S56, YES), step S57. The bill is determined to be a genuine note.

On the other hand, when it is determined in step S56 that the ratio Bno / B between the luminance value Bon of the non-infrared absorption portion and the luminance value B of the absorption portion is equal to or less than the reference value Thre (S56, NO), the process proceeds to step S58. Proceeding, the bill is determined to be a fake bill, and the determination is NG.
Next, the authenticity determination process using the fluorescence image in step S30 in FIG. 6 will be described with reference to the flowchart in FIG.

  First, the fluorescence image is normalized by affine transformation (FIG. 13, S61). Next, an area to be used for determination is set based on the selected banknote, that is, the currency type (yen, dollar, euro banknote) of the banknote subject to authenticity determination, the denomination and the direction of the banknote (FIG. 13, S62). In the setting of this area, for example, a banknote area where a known fluorescent image is obtained is specified.

Next, a ratio Rbg between the average luminance value of B (blue) pixels and the average luminance value of G (green) pixels in the fluorescent image in the determination area is calculated (S63 in FIG. 13).
Next, a ratio Rgr between the average luminance value of the G pixel and the average luminance value of the R (red) pixel in the fluorescent image in the determination area is calculated.

Next, a ratio Rbr between the average luminance value of the B pixel and the average luminance value of the R pixel of the fluorescent image in the determination area is calculated (FIG. 13, S65).
Reference values Thre1 to Thre1 to be determined based on the currency type, denomination, and banknote direction of the banknote selected as the target of the true / false determination are set (FIG. 12, S66).

And it is discriminate | determined whether ratio Rbg of the average luminance value of B pixel of a fluorescence image and G pixel is less than 1st reference value Thre1 (FIG. 13, S67).
When it is determined that the ratio Rbg of the average luminance value of the B pixel and the G pixel is equal to or greater than the first reference value Thre1 (S67, NO), the process proceeds to step S71, and the bill is determined to be a fake note.

Here, when the ratio Rbg between the average luminance values of the B pixel and the G pixel is equal to or greater than the first reference value Thre1, it is determined that the counterfeit note is for the following reason.
Since it is known that the luminance of the G pixel of the fluorescent image is highest in the case of a yen bill, the ratio Rbg of the average luminance value of the B pixel and the G pixel is less than the first reference value Thre1 in the case of a genuine note. It becomes. Therefore, when it is determined that the ratio Rbg between the average luminance values of the B pixel and the G pixel is equal to or greater than the first reference value Thre1, the bill is determined to be a fake bill.

When it is determined in step S67 that the ratio Rbg of the average luminance value of the B pixel and the G pixel is less than the first reference value Thre1 (S67, YES), the process proceeds to step S68, and the B pixel and the R pixel of the fluorescent image. It is determined whether or not the average luminance value ratio Rbr is less than the second reference Thre2.
When it is determined that the ratio Rbr of the average luminance values is equal to or greater than the second reference Thre2 (S68, NO), the process proceeds to step S71, and the bill is determined to be a fake note for the same reason as described above.

When it is determined in step S68 that the ratio Rbr of the average luminance value of the B pixel and the R pixel is less than the second reference Thre2 (S68, YES), the process proceeds to step S69, where the average luminance value of the G pixel and the R pixel is determined. It is determined whether or not the ratio Rgr is greater than the third reference value Thre3.
When the ratio Rgr of the average luminance value of the G pixel and the R pixel is larger than the third reference value Thre3 (S69, YES), the process proceeds to step S70, and the bill is determined to be a true bill. When the ratio Rgr of the average luminance value of the G pixel and the R pixel is equal to or smaller than the third reference value Thre3 (S69, NO), the bill is determined to be a fake note.

FIG. 8B is a diagram illustrating an example of the display of the authenticity determination result. FIG. 8B shows that the determination result is true, the currency type is Japanese yen, the denomination is 1000 yen, and the determined surface is the surface.
FIG. 14 is a diagram showing a fluorescence reaction part of banknotes (paper sheets) when irradiated with ultraviolet rays. In 1000 yen bills and 5000 yen bills of yen bills, when ultraviolet rays are irradiated, specific portions of the bills are created to emit fluorescence. For example, the luminance at a specific position of a fluorescent image photographed by the camera 11 is high. Authenticity can be determined by whether or not the reference value is exceeded.

  According to the above-described embodiment, an infrared image or fluorescent image of paper sheets (banknotes, securities, etc.) is photographed by the camera 11, and the brightness value of these images is compared with the reference value, whereby the paper sheet It is possible to easily determine whether a class is true or false. In addition, since the camera 11 is provided with a true / false determination function, the place of use is not limited, and the camera 11 can be used indoors or outdoors. Moreover, since the camera 11 is used, the cost of the apparatus can be reduced.

Even when the camera 11 performs authenticity determination, by displaying the infrared image and R, G, and B fluorescence images used for determination, the user can visually confirm what image is determined to be a fake bill. The effect is also obtained.
Furthermore, each of the captured fluorescent images R, G, B, or an infrared image is displayed on the display unit of the camera 11 so that the user can see the images and determine the authenticity of the paper sheet. Also good. At this time, a genuine note fluorescent image or infrared image may be displayed as a reference for authenticity determination.

The present invention is not limited to the above-described embodiment, and may be configured as follows.
In the embodiment, the position is moved by rotating the ultraviolet transmission filter 16 by a motor. However, the structure may be moved in the vertical direction or the horizontal direction.
In addition, the infrared transmission filter 23 and the infrared cut filter 22 are not limited to the structure attached to the same filter plate, and may be moved as different members.

  Further, the authenticity determination by the fluorescent image and the infrared image is not limited to the method of comparing the luminance values or the ratios of the luminance values, but may compare image patterns, luminance distributions, and the like.

It is an external view of the camera of an embodiment. It is a figure which shows the structure of the optical system of a camera. It is a figure which shows the characteristic of an ultraviolet transmissive filter, and the spectral intensity characteristic of strobe light. It is a figure which shows the characteristic of an infrared transmissive filter. It is a block diagram of a camera. It is a flowchart which shows the process of banknote mode. It is a figure which shows the display state of the position of a banknote. FIG. 8A shows an example of a warning display, and FIG. 8B shows an example of a display of a true / false determination result. It is a flowchart of a banknote position correction process. It is a flowchart of an infrared image authenticity determination process. It is a figure which shows an example of a currency selection screen. It is explanatory drawing of an infrared absorption characteristic. It is a flowchart of a fluorescence image authenticity determination process. It is explanatory drawing of the fluorescence image of a banknote.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Camera 12 Shooting lens 13 Flash part 14 Photometric sensor 15 Release button 16 Ultraviolet transmission filter 22 Infrared cut filter 23 Infrared transmission filter 26 Imaging element 27 Infrared filter drive part 39 Control part 41 Ultraviolet filter drive control circuit 42 Ultraviolet filter drive Unit 43 infrared filter drive control circuit 44 infrared filter drive unit 47 liquid crystal display unit 49 operation unit

Claims (19)

A camera having a flash unit and an imaging unit that emits light from the flash unit and irradiates a subject to perform imaging;
The flash unit has an ultraviolet transmission filter that can move to a shielding or retracting position with respect to the light emitting surface,
The camera
Shooting mode setting means for setting the shooting mode of the camera;
An ultraviolet transmission filter moving unit that moves the ultraviolet transmission filter to a position that shields the light emitting surface of the flash unit in response to a release instruction when a false bill detection mode is set by the photographing mode setting unit;
A camera with a counterfeit bill detection function, wherein after the ultraviolet transmission filter has moved to a shielding position, the image pickup means picks up a paper sheet by flash irradiation to obtain a fluorescent image. A camera having a flash unit and an imaging unit that emits light from the flash unit and irradiates a subject to perform imaging;
The imaging means has an infrared transmission filter that can move to a shielding or retracted position with respect to the imaging surface;
The camera
Shooting mode setting means for setting the shooting mode of the camera;
An infrared transmission filter moving unit that moves the infrared transmission filter to a position that shields the imaging surface of the imaging unit in response to a release instruction when the false bill detection mode is set by the imaging mode setting unit;
A camera with a counterfeit bill detection function, wherein after the infrared transmission filter has moved to a shielding position, an image is taken by flash irradiation on a paper sheet by the imaging means to obtain an infrared image.   2. The authenticity determination means for determining whether the paper sheet is a genuine note or a fake note based on the obtained fluorescent image or infrared image. Item 3. A camera with a fake ticket detection function according to Item 2.   When determining whether the paper sheet is a genuine note or a fake note by visual inspection, it is determined by switching and displaying each of the R, G, and B images of the fluorescent image. Item 1. A camera with a counterfeit bill detection function according to item 1.   3. With a counterfeit bill detection function according to claim 2, wherein when the paper sheet is determined to be a genuine note or a fake note, the infrared image is displayed for determination. camera.   In accordance with a release instruction, the camera performs a flash in a state where the ultraviolet transmission filter is retracted from the light emitting surface of the flash unit prior to flash photography in a state where the ultraviolet transmission filter shields the light emitting surface of the flash unit. The camera with a fake ticket detection function according to claim 1, wherein a visible image is obtained by photographing.   The camera performs flash photography with the infrared transmission filter retracted from the imaging surface prior to flash photography in a state where the infrared transmission filter shields the imaging surface of the imaging unit according to a release instruction. The camera with a counterfeit bill detection function according to claim 2, wherein a visible image is obtained.   8. The camera with a counterfeit bill detection function according to claim 6, further comprising paper sheet position correcting means for correcting the position of the fluorescent image or the infrared image based on the obtained visible image. Acquired image position appropriateness determining means for determining whether or not the acquired image after position correction by the paper sheet position correcting means is appropriate;
9. The counterfeit card detection according to claim 8, further comprising warning means for giving a warning when the acquired image position appropriateness determining means determines that the position of the acquired image of the paper sheet is inappropriate. Camera with function.   9. The camera with a false bill detection function according to claim 8, further comprising warning means for giving a warning when there is no paper sheet within a predetermined distance range based on a distance measurement result at the time of release.   The camera with a counterfeit bill detection function according to claim 10, further comprising a prohibiting unit that prohibits photographing when the warning is given.   The counterfeit ticket detection mode has a currency or other selection menu, allows selection of currency or other securities, and sets the determination criteria for the authenticity determination according to the type of the selected paper sheet. The camera with a fake ticket detection function according to claim 1 or 2.   The counterfeit ticket detection mode has a denomination selection menu, a target denomination can be selected, and a determination criterion for the authenticity determination is set according to the denomination of the selected paper sheet. The camera with a fake ticket detection function according to claim 1 or 2.   In the fake ticket detection mode, there is a front / back selection menu, the front and back of the target paper sheet can be selected, and the determination criteria for the authenticity determination are set according to the front and back of the selected paper sheet The camera with a fake ticket detection function according to claim 1 or 2.   4. The counterfeit note according to claim 3, wherein the authenticity determination means determines authenticity by comparing a luminance value or a ratio of luminance values of R, G, and B images of a fluorescent image with a reference value. Camera with detection function.   4. The camera with a counterfeit bill detection function according to claim 3, wherein the authenticity determination means determines authenticity based on luminance values of an infrared light absorbing portion and a non-absorbing portion in an infrared image. An ultraviolet transmission filter that shields or unshields the light emitting surface of the flash unit of the camera is provided.
When photographing paper sheets, the ultraviolet transmission filter shields the light emitting surface of the flash unit,
A fake note detection method using a camera, characterized in that a fluorescent image is obtained by imaging a paper sheet with flash irradiation in a state where a light emitting surface is shielded by the ultraviolet transmission filter. An infrared transmission filter that can be moved to the shielding or retracting position with respect to the imaging surface of the camera is provided.
When photographing paper sheets, the infrared transmission filter is moved to a position where the imaging surface of the imaging means is shielded,
A fake note detection method using a camera, wherein after the infrared transmission filter is moved, an imaging is performed on a paper sheet by flash irradiation by the imaging means to obtain an infrared image.   The fake using a camera according to claim 17 or 18, wherein it is determined whether the paper sheet is a genuine note or a fake note based on the obtained fluorescent image or infrared image. Ticket detection method.

Images