JP3531076B2 - Mark detection method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for optically detecting various marks such as bar codes and characters provided on various articles such as various prepaid cards such as pass tickets and telephone cards, and its method. The present invention relates to a detection device that implements a detection method, and particularly to a detection device in which a detection mark is formed with a fluorescent substance.

[0002]

2. Description of the Related Art Conventionally, as a mark detection method of this type, a mark is formed by using a fluorescent substance that emits light in an infrared wavelength region, and the light emitted to this mark and the emission center wavelength of the generated fluorescence are different. It is known that there is a method of determining the presence or absence of a mark by separating only the fluorescent component from the incident light using an optical filter (see, for example, Japanese Patent Publication No. 54-22326 and Japanese Patent Publication No. 61-18231). ).

On the other hand, the applicant of the present invention has previously been able to intermittently irradiate a mark formed of a fluorescent material with light, and detect the presence or absence of afterglow generated from the mark during the period when the irradiation light is stopped. A method and apparatus for detecting the mark formation position have been proposed (for example, see Japanese Patent Laid-Open No. 5-20512).

[0004]

However, in the method for separating the reflected light and the fluorescent light by using the above-mentioned optical filter, the emission center wavelengths of both lights are close to each other and the intensity of the reflected light is higher than that of the reflected light. Since the intensity of the fluorescence is extremely weak, it is technically difficult to accurately separate the two lights, and there is a problem that a large amount of the reflected light component remains and the detection accuracy deteriorates.

On the other hand, in the method of utilizing only the afterglow described above, the intensity of the reflected light is not a problem and only the fluorescence can be effectively separated and detected, while dust is present on the light incident surface of the detector. If the detection sensitivity decreases due to adhesion or the like, the absolute value of the afterglow generated from the mark also decreases, and as a result, the afterglow detection accuracy may decrease.

Furthermore, in the method of utilizing only afterglow, when external light having a wavelength equal to or near the wavelength of fluorescence is simultaneously irradiated, the light is directly input to the light receiving element and converted into an electric signal. As a result of the conversion, there is a possibility that fluorescent light may be mistakenly recognized as fluorescent light even though it is not generated. Therefore, in order to prevent such misidentification, it is necessary to shield the irradiation and detection positions of light from external light, and there is a disadvantage that the use environment is limited.

As a result of consideration of such inconvenience, the present inventors have found that the relationship between the light applied to the fluorescent substance and the generated fluorescence is the relationship between the applied voltage in the CR circuit and the terminal voltage of the capacitor. It changes while maintaining a phase relationship that is approximately equivalent to the relationship. Further, the waveform change shows a constant tendency in accordance with the fluorescent substance forming the mark. On the other hand, the external light generally has a substantially constant intensity or a random intensity change, and by utilizing the difference in waveform between the signals, even when various lights are mixed. It was found that only the fluorescent component can be accurately extracted from it.

That is, when a mark formed of a fluorescent material is irradiated with light which is intermittently intermittently emitted, the light emitted from the mark portion is reflected light of a constant intensity by the mark and a medium below the mark and its reflected light. The fluorescent light whose intensity increases and decreases at the same timing as the above, and the ambient light having a substantially constant level are superimposed. Therefore, the reflected light or the ambient light and the fluorescence can be separated by utilizing the difference in waveform between the two, and the type of the fluorescent substance can be specified by the difference in waveform due to the fluorescent component.

The present invention has been made on the basis of the above findings, and not only the intensity of the incident light and the intensity of the afterglow are detected, but the change in the waveform of the incident light is comprehensively judged. By determining the mark, not only the mark formation position can be accurately detected despite the deterioration of the detection condition of the fluorescence generated from the mark, but also the type of the fluorescent substance forming the mark is detected. It is an object of the present invention to provide a method and an apparatus capable of performing the above.

[0010]

A mark detecting method according to the present invention, as shown in FIG. 1, irradiates a mark 17 formed on an arbitrary medium 8 with a fluorescent substance with a light 17 to emit the mark 16. The fluorescence generated from the above is detected to detect the mark formation position and the type of the fluorescent substance formed.

Further, the step of intermittently irradiating the light 17 having a substantially constant intensity, the step of inputting the light 18 emitted from the irradiation position of the light 17 and converting into the electric signal, and the converted electric Among the signals, a step of dividing a signal intensity D1 at the start of light irradiation and a signal intensity D2 at the time of irradiation stop into a plurality of steps at a predetermined ratio to calculate one or a plurality of comparison values Tn; The magnitude Sn of one or more electric signals detected at a predetermined time interval from the start of irradiation of
n and comparing the magnitude relationship thereof, the magnitude relationship preset for the type of fluorescent substance to be detected, and the magnitude relationship determined above are compared with each other, and the fluorescence having the same magnitude relationship is detected. And a step of specifying the type of substance.

Further, the apparatus for carrying out the above-described mark detecting method is provided with a light irradiating means 10 for irradiating the light 17 having a substantially constant intensity while intermittently having a predetermined cycle, and an irradiation position of the irradiation light 17. The photoelectric conversion means 12 that takes in the emitted light 18 and converts it into an electric signal, and the signal intensity D1 at the start of irradiation of the light 17 among the converted electric signals.
Between the signal intensity D2 and the signal intensity D2 when the irradiation is stopped are divided into a plurality of portions at a predetermined ratio, and a comparison value setting means 13 for calculating one or a plurality of comparison values Tn; The magnitude S of one or more electrical signals to be generated
Fluorescence information in which the above-mentioned magnitude relationship is preset as fluorescence information for the waveform information detection unit 14 that compares n with the comparison value Tn to determine the magnitude relationship and one or a plurality of types of fluorescent substances to be detected. The storage means 15 and the fluorescent substance specifying means 9 for comparing the waveform information and the fluorescent information with each other to specify the types of fluorescent substances having the same magnitude relationship are provided.

The fluorescent substance forming the above-mentioned mark is supposed to generate fluorescent light 30 having a wavelength different from that of the incident light 17, and the incident light 18 and the fluorescent light 30 have substantially the same wavelength on the input side of the photoelectric conversion means 12. It is preferable to provide an optical filtering means 11 for selectively taking in the light component of.

[0014]

With the above-described structure, when the light irradiating means 10 irradiates the mark 16 with the light 17, the light irradiation position on the mark 16 produces fluorescence 30 having a predetermined wavelength in addition to the reflected light 67. As for the incident light 18 including the reflected light 67 and the fluorescent light 30 or the external light 70 other than the fluorescent light 30, only the light having the same wavelength as the fluorescent light 30 is selectively taken in by the optical filtering means 11, and then the photoelectric conversion means 12 is used. After being converted into an electric signal, predetermined signal processing is performed.

Here, in the comparison value setting means 13,
The intensity D1 of the incident signal at the start of irradiation of light corresponding to the time t1 in FIG. 1B and the signal intensity D2 at the time of stopping the irradiation corresponding to the time t3 are individually detected, and a distance between D1 and D2 is set in advance. One or a plurality of comparison values Tn are set by performing a division operation in a plurality of steps at a set ratio.

The comparison value Tn is obtained by the waveform information detecting means 1
4, the incident intensity Sn detected from time t1 to t5 from the start of the irradiation of light to the start of the next irradiation is input at the same time, and the detected value Sn is set to the comparison value Tn. It is determined whether or not it exceeds.

On the other hand, with respect to a plurality of types of fluorescent substances used as the constituent material of the mark 16, the same waveform information as described above is detected and held in the fluorescent information storage means 15 as fluorescent information.

Therefore, in the fluorescent substance specifying means 9,
The waveform information detected this time is compared with the preset fluorescence information, and if a match is found between them, it is determined that the mark 16 is formed of the fluorescent substance corresponding to the fluorescence information.

[0019]

As described above, the present invention detects the waveform change of the incident light 18 in synchronization with the irradiation light 17, and compares it with the waveform change previously detected for the fluorescent substance forming the mark 16. Since it is configured to specify the fluorescent substance, when the fluorescence component is reduced due to the deterioration of the optical sensor or the adhesion of dust, or when the irradiation light 17 is specularly reflected and a waveform change similar to the fluorescence component occurs in a pseudo manner. Also, the position where the mark is formed and the fluorescent substance forming the mark can be accurately detected.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail based on an example implemented in a mark detecting device for reading a bar code-shaped mark 16 formed on a cash card-shaped card 21, but the present invention is not limited to this. It is needless to say that the same can be applied to an apparatus for detecting mark information of various shapes including characters provided on various articles.

The card 21 has a base material 22 as shown in FIG.
For example, a white polyester film is used as the base material 22, and on the upper surface side of the base material 22, an undercoat layer 23 of any design whose reflectance is adjusted in advance is formed by printing, while the lower surface side is coated with a magnetic coating material. A magnetic layer 24 for rewritably recording information is formed. Furthermore, the base layer 2 on the upper surface side
A mark 16 made of a fluorescent substance is printed and formed on the surface 3 to fix the sub-information for security.

The mark 16 formed on the underlayer 23 corresponds to, for example, irradiation with light 17 in the infrared region.
A strip-shaped bar code-shaped mark 16 which is in an invisible state and is made of a fluorescent substance that emits fluorescence 30 having a wavelength different from the central wavelength of the irradiation light 17 and which is orthogonal to the longitudinal direction of the card 21 is formed. The mark 16 is used to record predetermined security sub-information such as a card issuing store code or a personal identification number on the card 21.

As the fluorescent substance forming the mark 16,
For example, neodymium (Nd), ytterbium (Yb),
Rare earth elements such as eurobium (Eu), thulium (Tm), praseodymium (Pr) and dysprosium (Dy), or a mixture thereof is used as an emission center, and these emission centers are phosphate, molybdate, tungstate, etc. It is preferable that the oxide is formed from a phosphor powder containing a matrix. However, it goes without saying that the material can be changed as appropriate as long as the fluorescent light 30 having afterglow property is generated by irradiating the light with an arbitrary wavelength.

In this embodiment, Li (NdO.9YbO.1) P4
By forming a fluorescent coating material containing a fluorescent substance such as O12 by screen printing, for example, when irradiated with excitation light in the near infrared region having a wavelength of around 800 nm, the infrared region having a peak value at a wavelength of around 1000 nm The fluorescent light 30 is generated, and afterglow of 90 to 10% is generated even after the light irradiation is stopped to generate afterglow of about 400 to 600 μs.

The mark detecting apparatus according to the present invention has a signal generating section 31 for generating various control signals and a card 2 formed as described above, as shown in FIG.
No. 1 running unit 32, a light irradiating unit 33 for the card 21 transferred by the card running unit 32, and a photoelectric conversion unit 34 for taking in the light 18 emitted from the position irradiated with the light 17 and converting it into an electric signal. And a signal S1 corresponding to the formation position of the mark 16 in the converted electric signal and a signal S1 corresponding to the fluorescent substance forming the mark 16.
The mark detection unit 35 that outputs 0 and the detected signal S1.
The data processing unit 36 for determining the data content on the card 21 from S10.

The signal generator 31 is at least the light irradiator 3
Drive signal S2 used in No. 3 and three kinds of timing signals S3, S4, S5 used in the mark detection unit 35, and a generation circuit 37 of a clock signal S6;
The control signal generating circuit 38 generates various control signals from the generated clock signal S6.

The clock signal generating circuit 37 is shown in FIG.
As described above, the pulsed clock signal S6 is continuously generated at a constant time interval of, for example, about 100 μsec. On the other hand, in the control signal generating circuit 38, the signal level is switched every time five clock signals S6 are input, so that the signal level is about 500 as shown in FIG.
A rectangular wave drive signal S2 whose level changes at time intervals of μsec is formed. Furthermore, the control signal generation circuit 38 outputs a pulse signal in synchronization with the input of the fourth, sixth, and ninth clock signals S6 from the rising edge of the drive signal S2.
As shown in (c) to (e), three types of timing signals S3 to S5 synchronized with the drive signal S2 are formed.

The card running section 32 supports both side edges of the card 21 by rollers 40 which are driven to rotate by a motor drive circuit 39 in accordance with the insertion timing of the card 21, and at a constant speed of, for example, about 200 to 400 mm per second. By horizontally shifting, the bar code-shaped mark 16 formed of a fluorescent substance on the upper surface side of the card 21 passes below the light irradiation unit 33 and the photoelectric conversion unit 34. The data regarding the operation timing of the motor drive circuit 39 is sent to the data processing unit 36 to inform it of the time required for the data processing for determining the content of the mark 16.

The light irradiator 33 is the signal generator 31 described above.
It is composed of a light emission source drive circuit 41 that amplifies the drive signal S2 output from the device and a light emission source 42 that generates the light 17 by the energization from the light emission source drive circuit 41.

As shown in FIG. 2, the light emitting source 42 has a light guide 44 made of glass fiber attached to a light emitting portion of a light emitting element 43 such as a light emitting diode which emits near infrared rays having an emission center wavelength of around 800 nm. It is a thing.
The tip of the light guide 44 is brought closer to the surface of the card 21 by a distance of 2 mm or less, and the entire light guide 44 is arranged on a plane orthogonal to the moving direction of the mark 16 and 45 from the horizontal direction. It is arranged with an inclination angle of -60 °.

A photoelectric conversion unit 34 for converting the light 18 emitted from the light irradiation position on the card 21 into an electric signal.
Is a detector 45 that converts the incident light 18 into a change in current.
And an AC amplifier circuit 46 that converts a current change into a voltage change and then amplifies it to a predetermined magnitude.

The detector 45 selectively passes only the light of the wavelength of the fluorescence 30 generated from the mark 16 on the light receiving surface of the light receiving element 47 such as a photocell or a photodiode having a light receiving sensitivity in the infrared region. A light guide 49, which is substantially the same as the light emitting source 42 side, is fixed via an optical filter 48.

Here, the tip of the light guide 49 on the detector 45 side is made to be adjacent to the tip of the light guide 44 on the light emission source 42 side, and on the plane orthogonal to the above-described transfer direction of the mark 16 and, for example, 105 to 115. By providing the inclination angle of about °, only the light 18 emitted from the irradiation position of the irradiation light 17 with respect to the surface of the mark 16 is captured. The captured light 18 is converted into a voltage proportional to the intensity of the incident light 18 by the light receiving element 47, amplified to a predetermined voltage value by the AC amplification circuit 46, and then input to the mark detection unit 35 to receive the mark. The signal S1 corresponding to the formation position of the mark and the signal S10 corresponding to the type of the fluorescent substance forming the mark are individually extracted.

The present invention is characterized by the structure of the mark detecting section 35, and includes a sample hold circuit 50 for measuring the change in the waveform shape of the incident light 18 illustrated in FIG. ~ Fourth comparison circuit 51/52/53 /
76 and first to third display circuits 54, 55 and 77.

As shown in FIG. 4, the sample hold circuit 50 includes a voltage buffer circuit 56 using an OP amplifier.
A capacitor 57 that holds the input voltage value on the input side of
Timing signal S sent from the signal generator 31 described above
The one provided with the analog switch 58 which is turned on by the input of 3 to S5 is set as one set of sampling circuits 60, and at least three sets thereof are provided, and in FIG. A series of voltage changes S7 corresponding to the intensity of the incident light 18 as illustrated are sampled individually and periodically at a plurality of time points, and each detected value thereof can be held until the next sampling time. .

In this embodiment, the timing signal S3 shown in FIG. 5 (c) is applied to the first sampling circuit 60a, and the voltage value immediately before the irradiation of the light 17 is stopped is used. The maximum value Vm of the incident light 18 shown by the thick line in (i) is detected. In addition, the intensity of the afterglow indicated by the broken lines in FIGS. 5G and 5I is determined by the voltage value immediately after the timing signal S4 shown in FIG. 5D is applied to the second sampling circuit 60b and the light irradiation is stopped. Is detected as a voltage value Vd. Further, the timing signal S5 shown in FIG. 5 (e) is applied to the third sampling circuit 60c, and the voltage V1 immediately before restarting the irradiation of the light 17 causes the incidence shown by the thin lines in FIGS. 5 (g) and (i). The minimum value of the light 18 is detected individually. In this way, the change of the waveform of the incident light 18 is obtained as the change of the voltage value, and the ratio of the fluorescence intensity to the whole is known.

Here, for example, at time t in FIG. 5F, depending on the kind of the fluorescent substance used for forming the mark 16.
The voltage waveform of the incident light 18 is different between 1 and t3 and after time t5. The present invention makes it possible to determine not only the presence / absence of a fluorescent substance but also the type of the fluorescent substance based on the difference in the waveform, specifically, the magnitude of the voltage value Vd at a predetermined detection timing.

For example, if the voltage value between Vl and Vm is 3
When the comparison values Vc1 and Vc2 are equally divided and set, the detection value Vd of the first fluorescent substance becomes the comparison values Vc1 and Vc.
It is assumed that the detection value Vd of the second fluorescent substance is between 2 and the comparison value Vc2 and Vm.

Here, the voltage values Vl.V taken from the above-mentioned first and third sampling circuits 60a, 60c.
Two variable resistors 62 having a difference voltage of m between them.
a.62b is divided into three to form two comparison values Vc1 and Vc2.

On the other hand, the first comparison circuit 51 includes the first and second
Two OP amplifiers 71a and 71b of
The detection value Vd is input to the negative input end of the amplifier 71, while the first comparison value Vc1 is input to the positive input end of the first OP amplifier 71a and the second comparison value is input to the positive input end of the second OP amplifier 71b. Vc2 is input respectively.

Therefore, when the mark 16 is made of the fluorescent substance A or B, at least the first comparison value Vc1 is obtained.
Since the detected value Vd is larger than that of the first OP amplifier 71a
A "1" signal is output from to notify the detection of the mark 16.

When the mark 16 is made of the first fluorescent substance A, the detection value Vd is smaller than the first comparison value Vc2, so that the output signal of the second OP amplifier 71b is "0".
To maintain. However, when the mark 16a is formed of the second fluorescent material B, the detection value Vd exceeds not only the first comparison value Vc1 but also the second comparison value Vc2, and thus FIG.
As at time t6, the second OP amplifier 71b also outputs “1”.
The signal is output. That is, the type of the fluorescent substance on which the mark 16 is formed is specified from the value of the output signal of the second OP amplifier 71b.

The second comparison circuit 52 compares the maximum value Vm output from the first sampling circuit 60a with a predetermined set value Vs, and outputs a predetermined signal S9 while the maximum value Vm is below the set value Vs. However, when the maximum value Vm exceeds the set value Vs, the output of the signal S9 is stopped, and the output end of the signal S9 is connected to the output side of the first comparison circuit 51 via the diode 63 that connects the output end in the forward direction. The signals are input in parallel to the third comparison circuit 53.

The third comparison circuit 53 applies the outputs from the first OP amplifier 71a and the second comparison circuit 52 of the first comparison circuit 51 to the minus side input terminal of the OP amplifier, compares the output with the set value, and outputs it to the output side. The switching element 64 by the provided FET is on / off regulated. While the output voltages from the first and second comparison circuits 51 and 52 are both below the set value, the "1" signal corresponding to the detection of the mark 16 is output to the data processing unit 36, but at least one of them is output. When the "H" level signal is output from the comparison circuits 51 and 52, the signal S1 sent to the data processing unit 36 becomes "0" indicating that the mark 16 is not detected.

The second OP amplifier 7 of the first comparison circuit 51
The output side of 1b is provided with a fourth comparison circuit 76 having substantially the same configuration as the third comparison circuit 53, and is configured to output the signal S10 sent to the data processing unit 36.

Therefore, during the period in which the output signal S8 from the first comparison circuit 51 is indefinite because the intensity of the incident light 18 is low, the second comparison circuit 52 outputs the "H" level signal S9 to the third comparison circuit. As a result of being applied to the minus side input terminal of 53, the output of the third comparison circuit 53 is forcibly set to the "0" state to notify the data processing section 36 that the mark 16 is not detected.

On the contrary, when the intensity of the incident light 18 is equal to or higher than a certain value and the mark detection is normally performed, the output from the second comparison circuit 52 is lowered to the "L" level, so that the first The third comparison circuit 53 operates in response to the change in the output level from the comparison circuit 51, that is, the detection of the fluorescence component, and the presence or absence of mark detection is determined as shown in FIG. 5 (h).

Regarding the time when the determination can be made by the third comparison circuit 53, the LED 65 of the first display circuit 54 provided on the output side of the second comparison circuit 52 is caused to emit light for display. Further, regarding the detection timing of the mark 16, the third comparison circuit 5
The LED 66 of the second display circuit 55 provided on the output side of No. 3 is made to emit light to notify. Furthermore, mark 16
The output timing of the fourth comparison circuit 76 is provided with the third display circuit 77 having substantially the same configuration as the second display circuit 55, and the LED is caused to emit light to notify the detection timing of the forming substance.

The capacitor 57 and the resistor 59 provided on the input side of the sample and hold circuit 50 and the capacitor 68 and the resistor 69 provided on the input side of the third comparison circuit 53 are:
Both of them form an integrator circuit, which prevents the input level from momentarily rising and malfunctioning due to the input of pulse noise.

Further, the period of the drive signal S2 in this embodiment is about 1 msec, which is set to about twice as long as the afterglow time of the fluorescent substance A forming the mark 16. However, both the period and the afterglow time have the same values. It can be appropriately changed and implemented.

Further, the sending time timings of the sample signals S3 to S5 are set closer to the blinking timing of the irradiation light 17 in accordance with the emission characteristics of the fluorescent light 30, so that the fluorescent component and the reflected light component are separated. It can be done more accurately. In that case, the value of the fluorescence 30 can be detected from the voltage values immediately after the start of irradiation of light and immediately before the stop of irradiation without detecting afterglow.

Further, the mark detecting section 35 can be configured in a digital manner using a microprocessor instead of performing the analog operation or comparison operation using the OP amplifier as described above. . In such a configuration, after the analog electric signal S7 output from the photoelectric conversion unit 34 in FIG. 3 is digitized by using the A / D converter, the mark detection unit 35 and By the data processing unit 36, as shown in FIG.
The data processing operation shown in FIG. 8 is performed. The other structure is substantially the same as that of the above-described embodiment, and will be omitted.

When the apparatus is started to start the data processing operation, predetermined initial setting is performed in step 1 of FIG. 6, and then in step 2, light irradiation corresponding to time t1 shown in FIG. 1 (b) is started. The incident light intensity D1 immediately before is acquired. After resetting the initial value for counting the number of data samplings to 0 in step 3, step 4
The irradiation light is turned on, and the incident light intensity acquisition step shown in FIG. 7 is started.

In this process, after waiting for a predetermined time in step 51 of FIG. 7, the counter is incremented by 1 in step 52, and the incident light intensity is acquired in step 53. Further, in step 54, it is determined whether or not the detection of the specified number of times is completed. If "NO", the process returns to step 51 and the above operation is repeated, and if "YES", this process ends, and Go to step 6 of 6.

In step 6, the incident light intensity D2 immediately before the stop of the light irradiation corresponding to the time t3 in FIG. 1B is acquired. Then, in step 7, turn off the irradiation light 17,
Further, the step of obtaining the incident light intensity shown in FIG. 7 is performed in substantially the same manner as above. Then, the procedure goes to the determination processing step whose details are shown in FIG.

In the judgment processing step, first, step 91 is entered to calculate the comparison value T. The comparison value T is
Since the absolute value of the incident light 18 changes depending on the data detection environment, the signal intensity D1 at the time t1 when the incident light intensity is the lowest immediately before the start of the light irradiation and the incident light intensity immediately before the stop of the light irradiation. The signal strength D2 at the time t3 which is considered to be the highest is used as a reference, and the two are divided by a preset number of stages, and the set value T is reset for each detection cycle.

Specifically, assuming that N is the total number of comparison values, for example, Tn = n / N (D2-D1)
The comparison value of N is obtained in step 91, the management table 73 shown in FIG. 9A is updated in step 92, and then the waveform information 74 is set in step 93.

The waveform information 74 is set by individually comparing the incident light intensities S1 to SN acquired in each step of FIG. 7 and the comparison values T1 to TN set in step 91 of FIG. The data is formed so that Tn and the magnitude relationship represented by Sn <Tn can be distinguished from each other. Figure 9 (b)
In the example shown in, the case of Sn ≧ Tn is ○, and Sn <
The case of Tn is illustrated by x. Since the relative shape data of the incident waveform is acquired from the matrix-shaped data, it is further determined in steps 94 to 96 whether or not the comparison with the comparison table 75 is made.

The comparison table 75 shows the waveform information 74 in advance for a plurality of types of fluorescent substances which are often used in the construction of the mark 16 by the method described above as shown in FIG. 9C.
Are summarized in a table format and stored in memory. Therefore, in step 94, the first comparison table 75a is fetched from the memory, the above-mentioned waveform information 74 and each data in the comparison table 75 are individually compared in step 95, and if a match is determined in step 96, step 96 is performed. At 98, the fluorescent substance corresponding to the comparison table 75 is specified, but if a mismatch is found in a part of the data at step 96, it is determined at step 97 whether the comparison operation for all comparison tables 75 is completed. To be done.

If the comparison table 75 remains, the process returns to step 94 to set the next comparison table 75. If all the comparison tables 75 are judged, the process moves to step 99 and the mark itself is deleted. It is determined that it has not been formed.

When this judgment processing step is completed, it is judged in step 10 of FIG. 6 whether or not all the marks 16 have been processed. If there is any processing, the procedure returns to step 2 and the above judgment processing is repeated. If it is determined that the mark processing has been completed, the determination processing in the mark detection unit 35 is completed.

The number of steps of setting the comparison value T and the number of samplings of the incident light 18 can be increased or decreased as appropriate. However, although the more accurate the waveform information 74 can be acquired as the number increases, it is difficult to completely match the waveform information 74 with the comparison table 75, and therefore it is necessary to set the error range in advance.

Instead of fixing the mark detection device side and moving the mark 16, for example, the light irradiation part 33 and the photoelectric conversion part 34 are formed into an integral portable probe shape, and the mark 16 side is fixed. The detecting device side may be manually or automatically changed. Further, the irradiation light 17 is scanned, and the light 18 emitted from the scanning position is detected by the detector 45.
You may make it detect by.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration of the present invention.

FIG. 2 is an explanatory diagram showing a light irradiation and detection state of a mark.

FIG. 3 is a block diagram showing an overall configuration of a mark detection device.

FIG. 4 is an electric circuit diagram showing details of a mark detection unit in FIG.

FIG. 5 is a waveform diagram showing a mark detection state.

FIG. 6 is a flowchart showing the overall procedure for identifying the type of fluorescent substance that digitally constitutes a mark.

7 is a flowchart showing an incident light intensity acquisition process in FIG.

FIG. 8 is a flowchart showing a fluorescent substance determination processing step in FIG.

9 is an explanatory diagram showing the configuration of each table used in the determination processing step of FIG.

[Explanation of symbols]

9 Fluorescent substance identification means 10 Light irradiation means 11 Optical filtering means 12 Photoelectric conversion means 13 Comparison value setting means 14 Waveform information detecting means 15 Fluorescence information storage means 16 mark 17 Irradiation light 18 incident light 19 Detection value 20 comparison value 31 Signal generator 33 Light irradiation unit 34 Photoelectric conversion unit 35 mark detector 36 Data processing unit 50 sample and hold circuit 73 Management table 74 Waveform information 75 comparison table

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Claims (3)

(57) [Claims] 1. A mark (16) formed on an arbitrary medium (8) with a fluorescent substance is irradiated with light (17), and fluorescence generated from the mark (16) is detected to detect the mark ( A method of detecting the formation position of 16) and the type of the formed fluorescent substance, the step of intermittently irradiating light (17) having a substantially constant intensity, and the emission from the irradiation position of light (17). The step of inputting the light (18) to be converted into an electric signal, and a predetermined ratio between the signal strength D1 at the start of light irradiation and the signal strength D2 at the stop of irradiation of the converted electric signal. And a step of calculating one or a plurality of comparison values Tn, and comparing the magnitude Sn of one or a plurality of electric signals detected at a predetermined time interval from the start of light irradiation with the comparison value Tn. Then
The step of determining the magnitude relationship, the magnitude relationship set in advance for the types of fluorescent substances to be detected, and the magnitude relationship determined above are compared with each other, and the type of fluorescent material having a matching magnitude relationship is identified. A method for detecting a mark, the method including: 2. A mark (1) formed of a fluorescent substance.
A device for irradiating 6) with light (17) and detecting the fluorescence emitted from the mark (16) to detect the formation position of the mark and the kind of the formed fluorescent substance. Light irradiating means (10) for irradiating a substantially constant light (17) intermittently at a predetermined cycle, and light (18) emitted from an irradiation position of the irradiation light (17).
Photoelectric conversion means (12) for taking in and converting it into an electric signal
Among the converted electrical signals, the signal intensity D1 at the start of irradiation of the light (17) and the signal intensity D2 at the time of irradiation stop are divided into a plurality of stages at a predetermined ratio, and one or more comparisons are made. Comparison value setting means (13) for calculating the value Tn, and 1 detected at a predetermined time interval from the start of irradiation of the light (17)
Alternatively, the waveform information detecting means (1) that compares the magnitudes Sn of a plurality of electric signals with the comparison value Tn and determines the magnitude relation thereof.
4) and the fluorescent information storage means (1) for presetting the above-mentioned magnitude relationship for one or a plurality of types of fluorescent substances to be detected.
5) and a fluorescent substance identifying means (9) for comparing the waveform information and the fluorescent information with each other to identify the type of the fluorescent substance having the same magnitude relationship. 3. The fluorescent substance forming the mark (16) is a fluorescent substance (3) having a wavelength different from that of the incident light (17).
0), and an optical filtering means (11) for selectively taking in a light component having substantially the same wavelength as the fluorescence (30) from the incident light (18) to the input side of the photoelectric conversion means (12).
The mark detection device according to claim 2, further comprising: