JPH10247263A - Fast reading method of micro-code character for discriminating forged paper money and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain picture data of high resolution even with respect to a subject in moving by oppositely arranging a photographing part and a subject at a short distance so as to judge authentication by pattern recognition analyzing a subject image obtained by the photographing part under a situation where a relative moving velocity between these is zero or low. SOLUTION: The subject A and an image pickup body B consisting of a linear sensor, etc., are shown and they are arranged with tight adhesion or in the state of a close contact where a distance d0 between the opposite arrangement is almost d0≈0. d1 shows the camera focal distance of the pickup body. Then, with respect to the moving of the image pickup body B in the direction of an arrow at a speed VD, the subject A parallelly moves in the same direction at a speed VM. When both of these bodies A and B are VM=VD+dVM, the photographing body B can photograph the subject A with a half-cylindrical lens C while scanning slowly (relative speed dVM) under a condition where a relative speed between these is dVM is VM>dVM, VD>dVM.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can discriminate the presence or absence of a proper printing portion by recognizing a printing pattern while moving a test object on which microcode printing has been performed at a high speed, and in particular, discriminating forged banknotes. The present invention relates to an apparatus and a method for reading microcode characters which are effective for high speed.

[0002]

2. Description of the Related Art Banknotes (for example, US dollar bills, German mark bills,
With regard to Japanese yen bills, etc., if it is possible to determine the presence or absence of these microcode printing sections in a state in which the bill is conveyed at a high speed, the bill can be authenticated and a highly reliable bill processing device capable of high-speed processing. Will be realized.

[0003] The transport speed of the currently used high-speed bill validator is in the range of 500 to 3000 mm / sec. When trying to read the printed pattern of these bills with a stationary camera while maintaining such a conventional processing capability, taking into account the function of a normal optical camera, a shutter of 1/500 second to 1/3000 second is required. The subject is between 6 mm and 0.17 between apertures (between film exposures)
mm.

[0004] On the other hand, in a banknote on which microcode printing has been performed, about 3 to 5 microcodes having a width of 10 to 50 microns are present at a width of 1 mm. In order to accurately determine this with the optical photographic means described above, 1
A resolution of more than a micrometer is required, and imaging under such a high-speed movement cannot be generally obtained.

[0005] Incidentally, the value required as a microcode reading condition in the course of a currently used high-speed banknote transfer device is that the transfer speed is 500 to 3000 mm / sec.
c. The size of one pixel is 1 mm × 1 mm, and the discrimination of pattern recognition is up to 40 sheets / sec. Have some degree of ability. On the other hand, the size of a microcode which is a character or a special figure to be recognized is a pattern of a character or a figure made of a pattern line having a size of 50 to 100 microns. For this reason, the conventional sensor cannot even catch such a fine target.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high-speed reading apparatus and a high-speed reading apparatus capable of accurately determining the reading of a microcode printing section under the conveying speed of a currently used high-speed bill conveying apparatus. Is to do. In order to read fine characters, a method of relatively enlarging a picture by reducing pixels or a method of optically enlarging an image can be considered. In addition, since the transport speed is too fast, it is necessary to solve a recognition failure caused by subject blurring caused by the subject moving while scanning the light receiving image sensor.

[0007]

SUMMARY OF THE INVENTION For this purpose, the present invention provides an image pickup section comprising a solid-state device or a high-speed image pickup tube and an object section such as a banknote or a fine pattern or an image thereof. Another object of the present invention is to make a true / false determination by pattern recognition in which a subject image obtained by an imaging unit is analyzed under a situation where the relative movement speed between them is zero or low at a very short distance.

In this apparatus, moving means for concentrically moving the image pickup unit and the object section is adopted, and object illuminating means for image pickup is provided. In addition, a timing unit for determining the start and end times of scanning necessary for scanning and photographing an appropriate portion of the subject portion by the imaging unit is provided. In this case, a one-dimensional imaging device including a CCD line sensor and a photodiode array is applied as the imaging unit. Further, the relative speed is restricted to zero or low speed under the conditions of the parallel movement of the two objects in the same direction at rest or constant speed, and the parallel movement of the two objects at different speeds in the same direction. In the pattern recognition, the electrical signal of the subject image obtained by the imaging unit is temporarily stored in a memory device, and the central control unit stores the pattern signal from the ROM memory storing the reference pattern for image comparison and the A comparison with the stored subject electric signal is performed, and an image pattern is compared and determined.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the case of taking a picture with a camera,
If the image of the subject is stationary with respect to the fixed image pickup body (camera), the image can be photographed as a still image because the camera shutter is kept open for a certain period of time and there is no movement of the image during that time. Also, when the subject and the image pickup body are translated in the same direction and at the same speed (the relative speed is zero), the still image can also be captured. If either the vehicle body or the imaging body is in a stationary state (a state in which the relative speed is other than zero), the subject image moves on the imaging surface during the opening time of the shutter of the imaging body. As a result, the captured image is disturbed, and the resolution of the image is reduced. In this case, the higher the moving speed of the other party (the higher the relative speed), the more disturbed the image becomes, the lower the resolution becomes, and the image cannot be identified. Therefore, during the shutter opening time on the imaging body side, when the relative speed is low within a condition that a reduction in the recognizable range of the resolution is acceptable, the imaging squad can scan the subject while scanning at a slow speed. It is possible to obtain a practically effective image including the case where the relative speed is zero.

[0010] By recognizing a pattern in the image pickup body of this image, it is possible to determine the search image of the subject, that is, the existence and authenticity of the microcode printing unit. In this case, a CCD (Cargo Couple Device) line sensor applied as an imaging body,
According to a one-dimensional imaging apparatus including a solid-state imaging device such as a photodiode array and a phototransistor array or an imaging tube, information can be electrically extracted while sequentially scanning a screen that is stationary or moving at a slow speed.
Also, in a two-dimensional imaging apparatus, an image can be similarly captured when the relative speed difference is zero.

In the acquisition of screen information, the distortion and enlargement or reduction of the image can be adjusted by optical means and electric means, but in order to stabilize the image, it is necessary to arrange the subject and the imaging body in this case close to each other. It is also effective to simplify the post-processing mechanism if the subject and the imaging body are configured to move in parallel when moving at a slow relative speed. For example, a CCD device is used as an image line scanner, and the output is input to an AD converter. Then, the output digital signal is represented by R
Temporarily store in AM memory. This RAM memory is 3
A type is provided and set to those during data input, data waiting, and data comparison.

By extracting the processing / data from the RAM memory and comparing it with the output data from the comparison reference data pattern storage ROM memory under the control of the high speed central control unit (for example, 16 to 32 bit class). ,
Pattern recognition can be performed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing the principle of construction according to the method of the present invention.
In the figure, A indicates a subject, B indicates an image pickup body composed of a linear sensor or the like, and the distance d0 between the opposed arrangements is almost d0 ≒.
It is arranged in close contact or close proximity to zero. d1 indicates the camera focal length of the imaging body. Then, the image pickup body B has the speed VD
, The subject A moves in parallel with the same direction at the speed VM. When the two bodies A and B are VM = VD ± dVM, the imaging body B moves the subject A slowly (relative speed dVM) under the condition that the relative speed dVM between them is VM >> dVM, VD >> dVM. ) Can be taken while scanning. C indicates a semi-cylindrical lens.

FIG. 2 shows an apparatus configuration based on the method of the present invention. First, the transfer large-diameter drum is indicated by a drum X and a drum Y. The bill Z is formed by these two drums X and Y.
Is transported while being attached to the outer periphery of the drum. Immediately before the bill Z enters the drums X and Y, two light-transmitting optical sensors (not shown) are arranged in order to determine the timing of starting rotation of the sensor drum 1 described later. The drum X and the drum Y have the same outer circumference, and are rotated at the same speed by the driving of the motor M while being connected by the belt 2. A pressing roller (not shown) is provided on the outer periphery of the drums X and Y so that the bill Z is brought into close contact with the drums X and Y to prevent slippage.

The micro-characters printed on the bill Z are
Since the printing part is specified, the drum sensor 1 is set at a related position where the part can be scanned by the imaging body B. An optical glass fiber which penetrates the inside of the sensor drum 1 so as to have a small inertia force and is attached to the hollow shaft 3 in a gyro shape, and which transmits light for illuminating an image pickup site of the bill Z. 5 is arranged at the center, and an electric wire 6 (see FIG. 3) for connecting the in-drum sensor unit 4 and the external interface unit is inserted around the center.

The sensor drum 1 will be described from the right end face to the left. In the figure, a light source is taken from the right end face, and a light shielding plate 7 for knowing the rotational position is provided inside the light source. Although a light bulb is used as the light source, an LED may be used. In this example, a lens 8 is used to collect light. Two coils 9 are accommodated in the groove on the outer periphery of the optical glass fiber 5 on the right end face of the sensor drum 1. The coil 10 opposite to the two coils 9 is also housed in the groove in the coupling unit on the opposite side. These are referred to as a first coil and a second coil from the outside. The two coil pairs form a magnetic coupling, and can transmit and receive an electric signal without contact between the rotating sensor drum 1 and the fixed-side coupling unit. A rotating ring-shaped electrode 11 is provided within a few millimeters from the right end of the sensor drum 1 to supply power required for operation of an electronic circuit in the sensor drum. The light emitting unit, the magnetic coupling unit, and the electrode unit are integrated into a unit.

The position of the light-shielding plate 7 is detected by a photo-interrupter 12 received also in the upper part of FIG. Then, the case where the light is shielded is determined as the fixed position. A pulley is provided next to the light-shielding plate 7, whereby the sensor drum 1 receives a rotational driving force. This drive source is a stepping motor. This is convenient for bringing the sensor drum 1 to a fixed position because the speed can be changed. The driving force of the motor 13 can be connected to and disconnected from the sensor drum 1 by the clutch 14 provided on the right side. That is, when the image data of the micro character portion of the bill Z is completed, the clutch 14 is turned off and the rotation is stopped by the brake 15 provided on the left side. And the light shielding plate 7
Rotate gradually to make fine adjustments so that is in place. Further to the left, there is a side plate 15, which fixes the sensor drum 1. Next, there are two side plates 17 for fixing the drum Y, and a pulley 18 for obtaining the same drive as the drum X is located between the side plates.

The sensor drum 1 has a sensor drum 1b having a diameter about 1 mm smaller than the diameter of the drum Y at a position on the left side of the drum Y through the center of the drum Y. The sensor drum 1 is hollow. The optical glass fiber 5 extending from the drum shaft 1a extends to the window. Then, a CCD 19 as an image pickup unit is attached so as to receive the reflected light if the subject A exists. A substrate 20 is provided on the opposite side of the center of the circle at a position where the center of gravity does not deviate from the center of the circle. The substrate 20 has a modulation and demodulation circuit for performing magnetic coupling. The clock is converted into a control signal for the CCD 19 from the clock, and
And modulates the signal from the CCD 19.

As the image pickup body B, in addition to a CCD sensor which is a solid-state image pickup device, one such as a photodiode array can be used.
A two-dimensional imaging device is suitable. The one-dimensional imaging density of 128 to 1024 pits is generally suitable for this application. Of course, a photodiode array, a transistor photo array or a high-speed imaging tube can be used in place of the CCD image element.

FIG. 4 is a perspective view showing an embodiment of the sensor section in the apparatus of the present invention. In this embodiment, a means for obtaining a light source from outside the drum is shown. The light source is arranged so that the optical axis is located on the rotation axis of the sensor drum 1, and transmits light through the optical glass fiber 5 disposed in the circular tube opened on the shaft 3 of the sensor drum 1 as described above. The light is applied to the transported bill Z through a light source window 21 opened in the drum surface, and the subject A is picked up by a CCD 19 through an imaging window 22 juxtaposed to the window 21.
To shoot. Reference numeral 23 denotes a CCD connector.
The sensor unit may be of a type installed inside a light source. In this case, a light introducing unit such as an optical fiber is not required, but a power supply terminal for an LED element or the like is required.

FIG. 5 shows a signal processing circuit configuration on the other side of the sensor drum (externally fixed) for performing pattern recognition in the method of the present invention, and FIG. 6 shows a signal processing circuit configuration installed in the sensor drum. The driving signal of the CCD is sent from outside using magnetic coupling. A timing control unit, which is an external circuit of the sensor drum, oscillates a basic high-frequency clock, one part of which becomes an AD conversion drive pulse of an AD converter, and the output of the converter is also written into a memory by a synchronization signal. Has become. A clock for CCD, a conversion start pulse for CCD, A
/ D conversion timing pulse, memory address generation circuit,
The memory write control signal operates.

The CCD clock and the CCD conversion start pulse are AM-modulated and sent to the first coil. FIG.
As shown in (1), the CCD conversion start pulse is multiplied on the CCD clock and sent to the first coil. The signal of the first coil on the receiving side is amplified, and after envelope detection, the comparator compares the magnitudes. Send signal to CCD. Detailed CCD timing is made internally.

The output signal from the CCD is an analog signal. Since the drum is rotating and cannot be connected by an electric wire, a method of outputting to the outside by a second coil which is a magnetic coupling portion is adopted. First, the signal is amplified, converted to an FM signal, and supplied to a coupling coil. In an external circuit (FIG. 5) of the sensor drum, the magnetic signal obtained by FM demodulation is input to an AD converter. Read timing is CC
Since it is necessary to synchronize with the output of D, read using the same clock as the CCD control clock supply circuit,
I try to take the timing.

The AD conversion timing needs to be converted in synchronization with the analog signal output from the CCD.
Also, when storing the data in the memory, it is necessary to synchronize with the output of the AD converter. This timing is created by the timing control unit. The data is converted into a digital value represented by 0 or 1 by the AD converter, and is stored in RAM memories # 1, # 2, #
3, one of the three memories is distributed and stored according to the regulation of the address generator. The number of bits of the signal conversion output is generally 16 to 32 bits. Through a central control unit 50 that performs pattern comparison through a data bus line of 16 to 32 bits of the signal stored in the RAM memory,
It is registered in the RAM as an input image pattern. On the other hand, the comparison reference pattern for pattern recognition is registered in the ROM in the same manner, and the data extracted from the ROM is subjected to pattern comparison by the high-speed determination CPU 50 so that the accurate determination of the microcode printing unit can be performed. It can be carried out. In order to determine an effective and effective image pattern at high speed, the RAM is replaced with a RAM # 1 for data input,
By providing a three-stage memory of the RAM # 2 for waiting for pattern determination and the RAM memory # 3 during pattern comparison work, it is possible to make an effective pattern recognition determination. English, Japanese, German,
... By preparing other items and changing the comparison software pattern, it becomes possible to identify all types of microcodes (characters).

[0025]

As described above, according to the present invention, the photographing section composed of a solid-state image pickup device or a high-speed image pickup tube and the subject section such as a banknote or an ultra-fine pattern or an image thereof are closely or extremely adhered. In a situation in which the object is moving at a close distance and the relative movement speed between them is zero or low, a true / false judgment is made by pattern recognition for analyzing the subject image obtained by the imaging unit. On the other hand, it is possible to easily obtain high-resolution image data, and it is possible to perform pattern recognition using an electrical information signal at a high speed by a relatively simple mechanism.

The above-described pattern recognition can be performed while scanning a subject using a one-dimensional image pickup device including a solid-state image pickup device. It can be performed. Further, by moving the subject and the imaging body in parallel, it is possible to perform the pattern recognition of the image by the one-dimensional or two-dimensional imaging, and it is extremely effective in simplifying the entire apparatus.

[Brief description of the drawings]

FIG. 1 is a diagram showing the configuration principle according to the method of the present invention.

FIG. 2 is a side view showing one embodiment of the device of the present invention.

FIG. 3 is an enlarged partial longitudinal sectional view of a main part in the embodiment.

FIG. 4 is a perspective view showing a sensor unit in the device of the present invention.

FIG. 5 is a diagram showing a circuit configuration for performing pattern recognition according to the method of the present invention.

FIG. 6 is an explanatory diagram of processing of a signal system in a sensor drum.

[Explanation of symbols]

 A Subject B Imager d Camera focal length X Drum Y Drum Z Banknote 1 Sensor drum 3 Axis 4 Sensor unit 5 Optical fiber 6 Electric wire 7 Light shield 14 Clutch 19 CCD

Claims (8)

[Claims] An image pickup unit comprising a solid-state image pickup device or a high-speed image pickup tube, and a subject portion such as a banknote or an ultra-fine pattern or an image thereof are closely attached or extremely opposed to each other, and Under these circumstances, the relative movement speed is zero or low, and authenticity is determined by pattern recognition that analyzes the subject image obtained by the imaging unit. Read method. 2. An image pickup section comprising a solid-state image pickup device or a high-speed image pickup tube, and an object section such as a banknote or an ultra-fine pattern or an image thereof, are opposed to each other with a fixed distance therebetween. Under such a configuration that both the imaging unit and the subject are at the same speed in the same direction, or their relative movement speed is low, and they are in a substantially parallel movement state, the optical imaging lens system is arranged between these equal intervals. A high-speed device for reading microcode characters for identifying forged banknotes, wherein the device is configured to obtain a subject image for determining the authenticity of the subject by pattern recognition. 3. A bill transporting large-diameter drum which rotates at a peripheral speed equal to the transport speed of bills and transports the bills, and has the same rotation center as the bill transport drums, and independently rotates and rotates the bills. A sensor drum having a diameter smaller than that of the transport drum; a light transmitting means and a light irradiating means for irradiating the bill with light inside the sensor drum; and a light receiving means for receiving data of the enlarged image and converting the data into an electric signal An imaging unit, and an external interface for sending a signal from the light-receiving imaging unit to the outside of the rotating body and receiving a control signal, and receiving the control signal sent from the outside via the external interface to perform demodulation conversion And a signal conversion means for receiving the electric signal from the light receiving / imaging means and converting it into a signal modulation outputted from the drum to the outside. Fast reading device counterfeit banknote discriminating microcode character to symptoms. 4. A bill transporting large-diameter drum which rotates at a peripheral speed equal to the transport speed of bills and transports the bills, has the same rotation center as the bill transport drum, and rotates independently of the bills. A sensor drum having a diameter smaller than that of the transport drum; a light transmitting means and a light irradiating means for irradiating the bill with light inside the sensor drum; and a light receiving means for receiving data of the enlarged image and converting the data into an electric signal Imaging means, signal conversion means for converting a signal from the light receiving and imaging means to a signal output from the drum to the outside, and sending a signal from the signal conversion means to the outside of the rotating body and receiving a signal from the outside 4. The high-speed reading device of microcode characters for discriminating forged banknotes according to claim 3, further comprising an external interface. 5. An external bulb light source section whose external interface projects light onto glass fiber fibers disposed at the center of rotation of said sensor drum, and electrodes disposed on the outer circumference of rotation as a connection circuit for supplying said signal conversion means. 5. The high-speed reading device for microcode characters for identifying forged banknotes according to claim 4, further comprising: a coil that couples the electric signal as a magnetic coupling. 6. A one-dimensional image pickup device such as a CCD line sensor, a diode photo array, a transistor photo array, or a CCD two-dimensional image element, a diode photo two-dimensional array element, a phototransistor two-dimensional array element, and an image pickup tube. The high-speed reading device for microcode characters for identifying forged banknotes according to claim 2 or 4, wherein the device comprises image reading means comprising a two-dimensional imaging device. 7. A high-speed reading device for microcode characters for discriminating counterfeit bills according to claim 5, wherein the sensor drum rotates at the same speed as or slightly slower than the bill transporting large-diameter drum. 8. A medium detecting sensor for detecting the entry of the transport medium into the bill transporting large-diameter drum, a sensor drum rotational position detecting means for detecting a rotational position of the sensor drum, and rotating the bill transporting large-diameter drum. Large diameter drum driving means,
A sensor drum driving unit for rotating the sensor drum, a clutch unit that is freely connectable between the sensor drum and the sensor drum driving unit, and the sensor drum rotating position until the conveyance medium reaches the medium detection sensor. The detection means is made to stand by at a specific position, the clutch means is disengaged, and thereafter, the sensor drum driving means is kept at a normal rotation, and when the medium detection sensor detects the arrival of the medium,
The high-speed reading device for microcode characters for discriminating forged banknotes according to claim 5, wherein the clutch unit is set in a connected state.