JP3069669B2 - Detection mark and mark detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention relates to a mark及beauty detection device for suitable detection provided in the various prepaid cards such as traffic tickets and telephone cards.

[0002]

2. Description of the Related Art Conventionally, as a method of detecting a mark of this type, a mark printed using black ink is irradiated with light, while a difference in reflectance between a printed portion and another portion is used to reflect the reflected light. A method of obtaining mark information by detecting a change in intensity has generally been used.

In addition to using a phosphor as a material for forming the mark and utilizing the fact that the excitation light and the emission wavelength of the phosphor differ from each other, only the light emitted from the mark is selectively extracted using an optical filter, and A method for obtaining information is also disclosed (for example, Japanese Patent Application Laid-Open No. 53-9600).
Reference).

Further, by printing a mark such as a bar code made of a photoluminescence layer using a phosphor emitting in the infrared wavelength region on a printed material such as a catalog, the display of the contents of the printed material such as a catalog is obstructed. Attempts have also been made to obtain information on the features, prices, etc. of printed products without doing this (for example, Japanese Patent Publication No. 54-1979).
No. 22326, JP-B-61-18231).

[0005]

However, in the above-described method of detecting a mark using reflected light, if the information recording surface is stained or damaged, the intensity of the reflected light is significantly reduced, and the information is erroneously read. There was an inconvenience.

On the other hand, in the method of detecting a mark using the light emission of the phosphor, the method is strong against stains on the recording surface, but because the emission center wavelengths of the excitation light and the light emission are close to each other, the two can be completely detected. It is difficult to separate and detect, and there is a possibility that the reflected light is superimposed on the detected light and the detection accuracy is reduced. Further, it is known that a bar code formed by a phosphor layer formed on a printed material as described above has a high probability of occurrence of a reading error.

The inventors of the present invention have conducted studies to find out the cause, and as a result, the luminous intensity of the phosphor layer is larger than expected with respect to the reflectance of the underlayer on which the phosphor layer is formed. By controlling the reflectance of the underlayer to a predetermined value or more, the emission intensity emitted from the phosphor layer increases, and a sufficiently large difference is set between the detection voltage obtained from the phosphor layer and the underlayer. It has been found that mark reading errors can be reduced.

That is, as shown in FIG. 1, for example, an underlayer 7 to be described later is provided on a substrate 4 made of a white polyester film containing a white pigment, and further, on the underlayer 7, for example, a wavelength of 800 nm A bar code-like mark 9 is formed by the phosphor layer 8 that generates light b having a wavelength of 1000 nm different from the wavelength of the excitation light a upon incidence of the excitation light a, and an optical filter 45 that blocks the excitation light a is provided. The voltage value output from the detection means was measured by the control means.

The underlayer 7 has a center wavelength 8 of the excitation light a.
Four types having different reflectances with respect to light of 00 nm, for example, A (reflectance at the excitation light wavelength is about 78%) using the base material 4 itself as the base layer 7, and a white base layer B containing titanium oxide powder (the same reflection) The ratio was about 39%), a silver base layer C containing aluminum powder (having a reflectance of about 34%), and a black base layer D containing magnetic powder (having a reflectance of 5%). FIG. 2 shows the results obtained by forming the phosphor layers 8 on the respective underlayers 7 with the film thickness being varied from 0 to 200 μm and measuring the voltage value output from the light detecting means.

In the case of performing detection using the afterglow b 'of the mark 9 portion, only the afterglow intensity of the light b emitted from the phosphor layer 8 needs to be considered. When b is used directly for detection, the output voltage ratio between the portion of the underlayer 7 alone and the portion provided with the phosphor layer 8 becomes a problem, and the value is at least 1.6 times from experiments and the like. Since the degree is necessary, the lower limit value for each of the underlayers A to D is indicated by a straight line group of A 'to D'.

Therefore, the intersection between the two is 0.4 μm for the underlayer A, 2 μm for the underlayer B, and 3 μm for the underlayer C.
m, the underlayer D is 5 μm, and it can be seen that if the film thickness of the phosphor layer 8 is set to be greater than that, the necessary minimum detection output can be obtained when the underlayer 7 is uniform.

On the other hand, when the reflectance of the underlayer 7 is partially different like the printed surface of the design, the thickness of the phosphor layer 8 to be formed is 10 μm, and the underlayer A has the highest reflectance. Assuming that it is necessary to fall within the output voltage range v equal to or greater than A 'in order to detect the reflection from the underlayer 7 and the light emission from the phosphor layer 8 separately. The underlayer B satisfies this condition, but is unsuitable for the underlayer C, and it is understood that the reflectance must be regulated to about 39% or more, which is the reflectance of the underlayer B.

In each of the above-mentioned samples, the change in the reflectance was measured while changing the wavelength of the light source from 400 nm to 900 nm with respect to the portion having only the base layer 7 and the portion having the phosphor layer 8 formed thereon. FIG. 3 shows an example in which the base layer A and the phosphor layer 8 of 35 μm are formed thereon.

Further, when the amount of decrease d in reflectance at 800 nm, which is the excitation light wavelength this time, due to the provision of the phosphor layer 8 is regarded as “absorptivity” in the phosphor layer 8, various underlayers are considered. FIG. 4 summarizes the relationship between the similar absorption rate and the output voltage of the detector in A to D.

From the above experimental results, the output voltage of the detector increases and decreases substantially in proportion to the "absorptivity" of the phosphor layer 8, and the absorptivity of the phosphor layer 8 further increases.
It can be seen that it largely depends on the reflectance of the phosphor layer 8 and the thickness of the phosphor layer 8.

The present invention utilizes the findings based on the above-described experiments, and has as its object to provide a detection mark in which detection errors are reduced as much as possible. It is another object of the present invention to provide a detection mark which improves detection accuracy when a mark is formed in a portion where the reflectance of the underlayer is not uniform.

[0017] were present invention Hama, and an object thereof is to provide a mark detecting apparatus that can detect accurately a mark formed on the barcode form.

[0018]

As shown in FIG. 1, a detection mark 9 according to the present invention has a pattern formed of a thin phosphor layer 8 and an infrared ray irradiated from the front side. In the infrared region, corresponding to the excitation light a in the region
That different emission b or afterglow b wavelengths' is be one that is generated, on the back side of the phosphor layer 8, among the above-mentioned excitation light a
Underlayer 7 whose reflectance at the central wavelength is regulated to a set value or more
Is formed.

When the above-described phosphor layer 8 is formed on the underlayer 7 having a substantially uniform reflectance, the above-mentioned excitation light a
The illuminance of the light that selectively detects the light emission b emitted from the phosphor layer 8 at the time of emission is substantially equal to the illuminance of the light that selectively detects the reflected light c of the base layer 7 under substantially the same conditions . For illumination, set a value greater than 1.
The reflectance of the underlayer 7 and the phosphor are set so as to be a fixed multiple or more.
Preferably , the thickness of layer 8 is determined .

When the phosphor layer 8 is formed on the underlayer 7 having a non-uniform reflectance, the light emission b emitted from the phosphor layer 8 when the above-mentioned excitation light a is irradiated is selected. Of detected light
The minimum value of the illuminance is the same as the illuminance of the light that selectively detects the reflected light of the base layer 7 having the highest reflectance under substantially the same conditions .
In the underlayer 7 so as to be a set multiple larger than 1 or more.
It is preferable to determine the minimum value of the reflectance and the thickness of the phosphor layer 8 .

[0021]

[0022]

On the other hand, the mark detection device according to the present invention
While relatively moving with the mark 9 formed on the phosphor layer 8,
Light irradiating means for irradiating the mark 9 with excitation light a, and light disposed adjacent to the light irradiating means and selectively extracting light b or b 'emitted from the focal position f of the excitation light a Detection means. The optical axes L1 and L2 of the light irradiating means and the light detecting means are arranged so as to be inclined with respect to each other on a plane parallel to an xy plane orthogonal to the direction of the mark 9, where z is a transition direction. .

The above-mentioned mark 9 is formed in a narrow band shape extending in parallel to a direction x orthogonal to the transition direction z of the mark 9, and the phosphor layer 8 constituting the mark 9 is formed as follows.
Irradiation with the excitation light a in the infrared region allows generation of light b in the infrared region different from the center wavelength of the excitation light a, while the light irradiation means includes a light guide 43 having a predetermined length on the light emitting surface of the light emitting element 42.
It is preferable that the light detection unit connects the light guide 46 to the light receiving surface of the light receiving element 44 via an optical filter 45 that blocks the incidence of the excitation light a.

[0025]

In the above construction, by providing the underlayer 7 on the back side of the phosphor layer 8, the intensity of the light emission b or the afterglow b 'emitted from the phosphor layer 8 when the excitation light a is irradiated is maintained at a sufficiently high level. Is done.

Further, the reflectance of the underlayer 7 is uniform, and the intensity of the reflected light c at the underlayer 7 and the intensity of the light emission b at the phosphor layer 8 are, for example , set multiples or more at the stage after photoelectric conversion. Is maintained, the boundary between the underlayer 7 and the phosphor layer 8 is clearly detected.

Further, when the phosphor layer 8 is formed on the underlayer 7 having a non-uniform reflectivity, the phosphor layer 8 is formed on another underlayer having a lower reflectivity than the reflected light intensity of the underlayer having the highest reflectivity. By setting the reflectance of the underlayer 7 so that the emission intensity output from the phosphor layer 8 thus maintained maintains a value that is equal to or more than a set multiple in the state of photoelectric conversion, for example , the reflectance of the underlayer 7 is reduced. This prevents the output fluctuation of the emission intensity from the phosphor layer 8 caused by the fluctuation from being erroneously recognized as the boundary between the mark 9 and the base layer 7.

[0028]

In the mark 9 detecting device, when a control signal is sent from the control means to the light irradiating means, the irradiating means irradiates the mark 9 with excitation light. Here, the optical axes L1 and L2 of the excitation light a and the incident light b or b 'are inclined with respect to the surface of the mark 9 on a plane parallel to the direction in which the mark 9 extends, and the focal positions f of the two coincide. Therefore, the spread of light in the width direction of the phosphor layer 8 on the mark 9 is
The diameter of the excitation light immediately after emission from the light irradiating means is regulated as a limit, and the resolution along the transition direction of the mark 9 is kept high.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be more specifically described based on an example in which a card 1 on which arbitrary data is recorded and a card reader / writer 2 shown in FIG. 5 for processing data recorded on the card 1. explain.

[0031]

[Card] As shown in FIGS. 7 and 8, the card 1 is a white polyester containing about 5.5 cm in length, about 8.5 cm in width, and about 188 μm in thickness as a base material 4. By using a film and printing an arbitrary design 5 on the upper surface side of the base material 4 and applying a magnetic paint on the lower surface side in substantially the same manner as in the prior art, the main information is rewritably recorded. The layer 6 is formed.

According to the present invention, in addition to the above-described structure, an underlayer 7 whose reflectance is adjusted is further provided on the magnetic layer 6, and a mark 9 made of a phosphor layer 8 is formed on the underlayer 7 by printing. The security sub-information can be fixed.

The underlayer 7 is prepared by mixing and dispersing, for example, a composition obtained by adding 50 parts by weight of aluminum powder, 50 parts by weight of a polyester resin (manufactured by Toyobo Co., Byron 280) and 200 parts by weight of methyl ethyl ketone by a ball mill for 48 hours. After adjusting the coating material for the formation layer, it is applied and dried over the entire surface of the magnetic layer 6 to form a uniform underlayer 7 having a thickness of about 4 μm.
Was formed.

The mark 9 formed on the underlayer 7 described above
As shown in FIG. 1, a phosphor layer 8 that generates infrared light b having a wavelength different from the center wavelength of the excitation light a in response to the irradiation of the excitation light a in the infrared region. hand,
A strip-shaped bar code mark 9 orthogonal to the longitudinal direction of the card 1 is formed, and the security information such as a card issuer code or a personal identification number is recorded on the card 1 with the mark 9. doing.

The phosphor layer 8 is made of neodymium (Nd),
Rare earth element such as ytterbium (Yb), eurobium (Eu), thulium (Tm), praseodymium (Pr), dysprosium (Dy), or a mixture thereof is used as a luminescent center, and the luminescent center is phosphate, molybdate , A phosphor powder containing an oxide such as tungstate in the matrix, or mixed with an ultraviolet-curable resin,
Alternatively, a fluorescent paint is prepared by mixing and dispersing with a binder resin such as a vinyl chloride-vinyl acetate polymer, a polyurethane resin, a polyester resin, and an alkyd resin, an organic solvent such as methyl ethyl ketone, tetrahydrofuran, and ethyl cellosolve, and the like. Coating on the underlayer 7
It is formed by drying.

Specifically, Li (Nd0.9YbO.1) P4O1
2 is formed by screen printing a fluorescent paint containing a phosphor such as
When irradiating near-infrared excitation light a in the vicinity, 1000 n
In addition to generating infrared light b having a peak value at a wavelength near m and stopping light irradiation, as shown in FIG.
The decay time of 90 to 10% is configured to generate an afterglow b ′ of about 400 to 600 μs.

It should be noted that the content of the phosphor powder in the phosphor layer 8 is such that the emission b
So that the weight ratio to the binder resin is 1: 2 to 2
It is preferred to be in the range of 2: 1.

The thickness of the phosphor layer 8 is 0.5 μm to 2 μm.
It is selected from the range of 00 μm, but is preferably 1 μm or more in order to obtain a sufficiently stable output, and more preferably 100 μm or less in order to maintain durability.

[0039]

[Card reader / writer] The card reader / writer 2 is shown in FIG.
As shown in FIG. 1, the system comprises a card reader / writer main body 10, a portable personal computer 11 for sending necessary data to the card reader / writer main body 10, and a printer 12 for displaying a writing state of the card 1.

That is, on the personal computer 11 side, information such as the number of cards to be processed, the issuing store code, the denomination, or the issuance time of the card 1 to be processed is previously input and stored from the keyboard. Here, the personal computer 11 and the card reader / writer body 1
0 is connected to each other via a serial line 13 of the RS-232C standard, and when the storage data described above is sent to the card reader / writer main body 10 side, the card reader / writer main body 10 uses the card 1 based on the received information. The main information is automatically written into the memory.

The card reader / writer body 10 has a one-chip microcomputer for control and operates independently based on the received information. The card reader / writer 10 is composed of a plurality of stacked cards 1.1,. A card supply unit 14 for taking out cards one by one, and a mark detection unit 1 for reading out sub-information of the card 1 taken out from the supply unit 14 and judging pass / fail
5, a defective card ejection unit 16 for ejecting a card determined to be defective by the detection unit 15, a card data processing unit 17 for reading / writing main information of the card 1, and ejecting the card 1 on which the main information is written. It comprises a card storage section 18 and a control section 19 for sending a control signal to each of the above-described sections.

As shown in FIG. 6, the card supply unit 14 is provided on the upper part of the guide frame 20 in which the cards 1 are stacked and stored in a horizontal state with the formation surface of the mark 9 down. A counterweight 21 for applying a predetermined pressing force in the vertical direction from above is provided so as to be swingable in the up and down direction, and a card discharge roller 23/24 is provided to slightly protrude from the bottom wall 22 of the guide frame 20, and the guide is provided. Front 25 of frame 20
On the same side as the bottom wall 22, a slit 26 through which only one card 1 can pass is provided for fine adjustment. Further, the card 2 is attached to the card discharge roller 23 on the slit 26 side.
3, the lowermost card 1 in contact with the roller 23 is slit 2 by driving the motor 27 to rotate in conjunction with the input of a drive signal from the control unit 19.
The card 1 is fed to the mark detection unit 15 one by one with the mark 9 being formed with the surface on which the mark 9 faces downward.

[0043]

[Mark Detection Unit] The present invention is characterized by the configuration of the mark detection unit 15. As shown schematically in FIG. 6 and FIG. A traveling unit 30 that is horizontally moved downward, a light emitting source 31 that is disposed below the card running surface and that intermittently irradiates the mark 9 on the card 1 with the excitation light a, and that the light emitting source 31 is turned off A detection head 33 integrally housing a detector 32 for detecting afterglow b ′ emitted from the mark 9 therein;
A detection circuit 34 for processing the signal output from the detector 32
And

The running section 30 of the card 1 is shown in FIGS.
As shown in FIG. 3, guide rails 35, which horizontally support both side edges of the card 1, are fixed in parallel along both sides of the traveling path, and a driving roller 37 rotated by a motor 36 is provided.
And a pair of pressing rollers 39 and 40 for applying a pressing force to the card 1 from above the rollers 37 and 38, one set each corresponding to the entrance and the exit of the mark detection unit 15. Further, an interrupter 41 is provided at the entrance position of the mark detection unit 15, and when it is detected that the card 1 has been sent from the card supply unit 14, the motor 36 rotates forward to
Is horizontally shifted at a constant speed of about 200 to 400 mm per second, and a bar code-like mark 9 formed by the phosphor layer 8 on the lower surface side of the card 1 passes above the light emitting source 31 and the detector 32 in order. I am doing it.

As shown in FIG. 9 and FIG. 10, the light emitting source 31 has a diameter of 3.0 mm and a length of 3.0 mm in a light emitting portion of the light emitting element 42 such as a light emitting diode which emits near-infrared light having a light emission center wavelength of about 800 nm. A glass fiber light guide 43 having a length of about 7.0 mm is attached. The leading end 43a of the light guide 43 is brought close to the surface of the card 1 to a distance of 2 mm or less, and the entire light guide 43 is placed on a plane orthogonal to the direction in which the mark 9 moves and 45 degrees from the horizontal direction. And an inclination angle α of about 60 °. Further, according to the signal S1 output from the control unit 19, the light emitting elements 42 are turned on at the substantially equal time intervals of 500 μsec for both the lighting time T1 and the turning off time T2 as shown in FIG. Are turned on and off so that the mark 9 is irradiated with the excitation light a intermittently.

The detector 32 is provided via an optical filter 45 for selectively passing afterglow b 'generated from the mark 9 on a light receiving surface of a light receiving element 44 such as a photocell having a light receiving sensitivity in an infrared region. , A light guide 46 substantially similar to that of the light emitting source 31 is fixed, and after being converted into an electric signal S2 corresponding to the afterglow by the light receiving element 44, a signal corresponding to the mark 9 is formed by the detection circuit 34 described later. . Here, the distance that the mark 9 moves during the irradiation period of the excitation light a by the light emitting source 31 is 0.2 mm or less, and one light irradiation and afterglow detection operation are performed in a stopped state. Can be regarded as having. Therefore, the tip 46a of the light guide 46 on the detector 32 side is made to be adjacent to the tip 43a of the light guide 43 on the light emission source 31 side, and the inclination of 105 to 115 ° is on a plane orthogonal to the above-mentioned transition direction of the mark 9. By providing the angle β, only the afterglow b ′ emitted from the irradiation position of the excitation light a on the surface of the mark 9 can be detected, and the excitation light a is irradiated on the surface of the mark 9 as perpendicularly as possible. The afterglow b ′ emitted in the vertical direction is detected to improve the detection efficiency.

8 and 9 along the light emitting surface 43a of the light emitting source 31 and the light incident surface 46a of the detector 32.
The width of the light beam in the width direction of the mark 9 in the excitation light a emitted from the light emitting source 31 is limited by covering the light beam with the cover 32 with the cover 48 having the slit 47 on the narrow band as shown in FIG. The detection accuracy of the mark 9 is improved by also restricting the light input in the width direction of the mark 9.

Further, the portion near the light guide tip 43a of the light emitting source 31 is raised slightly upward, so that the raised portion 5
2 is brought into contact with the lower surface of the card 1 so that the distance between the detection head 33 and the card 1 can be maintained at a stable and constant value.

From the light receiving element 44 of the detector 32 to the detection circuit 3
When the irradiation of the excitation light a is started, the intensity of the signal S2 input to the light source 4 cannot be blocked by the optical filter 45 in the light emission b emitted from the phosphor layer 8 as shown in FIG. The reflection component c of the excitation light a is superimposed and rises. When the irradiation of the excitation light a is stopped, the afterglow b ′ emitted from the phosphor layer 8 is emitted.
It decreases exponentially only by. Therefore, the output signal S
2 is input to the comparison circuit 50 that operates in response to the light-off period of the light-emitting element 42 and is compared with the set value Vs,
A rectangular wave signal S3 is formed corresponding to the formation position of the mark 9 immediately after the light emitting element 42 is turned off, and is input to the determination circuit 51.

The determination circuit 51 checks the presence or absence of the rectangular wave signal S3 immediately after each of the light emitting elements 42 is turned off.
As shown in FIG. 2 (d), the width of the mark 9 in the running direction of the card 1 is sequentially detected by integrating the number of the continuously input rectangular wave signals S3. Further, a pattern obtained from each width detected as described above is compared with a previously stored barcode pattern to decode the detection data, and the decoding result is displayed on the display unit 52 at the same time. If the detected data is appropriate, the motor 3
The normal rotation operation of No. 6 is continued and sent to the card data processing unit 17. However, if the data is detected to be incorrect or if the data itself has not been detected,
The card 1 is sent to the defective card ejection unit 16 by reversing the motor 36 in the traveling unit 30.

The defective card ejection section 16 is provided with the card supply section 1.
4 is provided with a check roller 55 that allows only the ejection of the card 1 from the supply section 14, a receiving section 56 is provided below the card supply section 14, and a base end of the guide rail 35 on the lower side. 35a is inclined toward the receiving portion 56 described above. With this configuration, the mark detection unit 15
Is discharged from the card 1 to the receiving portion 56 side by the non-return roller 55 and the guide rail base end 35a.

On the other hand, the card 1 sent to the card data processing section 17 performs a predetermined data write operation on the magnetic layer 6 on the back side of the card by the magnetic head 57,
The card 1 is ejected to the card storage unit 18 and the information corresponding to the processing operation is returned to the personal computer 11, and the processing result is displayed on the display 58 and the printer 12.

[0053]

Another Embodiment FIG. 13 is a waveform diagram showing another embodiment of the afterglow detection procedure shown in FIG. 11 described above. In this embodiment, as shown in FIG. 13 (a), the lighting time T1 of the light emitting element 42 is maintained for a time necessary and sufficient to excite the phosphor layer 8 constituting the mark 9, while the light emitting time is turned off. T2
By limiting the time to the minimum necessary for detecting the afterglow b ′, the excitation light a
Is shortened as much as possible, the number of pulses of the signal S3 detected while scanning one mark 9 is increased, and the accuracy of measuring the mark width can be improved.

Also in this embodiment, the detection signal S corresponding to the light emission from the phosphor layer 8 indicated by the solid line in FIG.
It is also possible to compare 2 with the set value Vs and generate a detection signal as shown in FIG. 13C corresponding to a period exceeding the set value. However, in this embodiment, FIG.
A gate time T4 for afterglow detection, in which detection margins T3 and T5 are provided before and after substantially at the center of the light-off time T2 as shown in FIG.
Is set, and a logical AND with the above-mentioned FIG. 13 (c) is taken to generate a signal S3 as shown in FIG. 13 (e).

The times T1 to T5 described above can be changed as appropriate in accordance with the afterglow time of the phosphor layer 8 and the required detection accuracy. In the example of FIG. 13, T1 is set to 500 μm.
sec, T2 20 μsec, T3 and T5 5 μsec
c, and a waveform diagram when the gate time T4 is 10 μsec. Further, the dash-dot line in FIG. 13B illustrates an output waveform from the detector 32 when a portion where the mark 9 is not formed by the phosphor layer 8 is detected for comparison.

As a result, the SN ratio at time t2 at the time of detecting afterglow was about 60 dB, whereas the SN ratio at time t1 at the time of detecting light emission was about 13 dB, and the afterglow was detected. Thus, it was confirmed that the S / N ratio was significantly improved.

FIG. 14 shows another embodiment of the above-described mark detection section 15 in which a light emitting source 31 is provided at an upstream position in the transition direction of the mark 9 formed by the phosphor layer 8 and a detector 32 is provided at the downstream side. In addition, a configuration is adopted in which light is shielded between the two by a partition wall 80.

With this configuration, as shown in FIG.
The mark 9 excited by the excitation light a emitted from the light emitting source 31 starts emitting light b and continues to emit afterglow b 'even after being separated from the light emitting source 31 as shown in FIG.
As for the afterglow b ′, only the afterglow b ′ generated from the position facing the detector 32 through the slit 47 a provided in the partition wall 80 is selectively incident on the detector 32 as shown in FIG. The detection operation is performed in substantially the same manner as in the above-described embodiment.

In this configuration, although the mark 9 is formed using a phosphor having a long afterglow time, or a phosphor having a short afterglow time is used, the traveling speed of the mark 9 is sufficiently high. This configuration is effective when the afterglow has sufficient intensity even when the mark 9 moves to the position of the detector 32.

When a large variation in the moving speed of the mark 9 is expected, such as when the mark 9 is moved manually, the detectors shown in FIGS. The detector 32 can be switched and used according to the magnitude of the speed.

FIGS. 15 and 16 show still another embodiment. In the embodiment shown in FIG. 15, the light emitting source 31 and the detector 32 are vertically separated from each other with the mark 9 as the center. The mark 9 is formed on at least a part of the base material 4 on which the mark 9 is provided. With such a configuration, as shown in FIG.
The excitation light a emitted from 1 is applied to the mark 9 through the base material 4, and the phosphor layer 8 constituting the mark 9 emits light.
In this state, as shown in FIG. 15B, when the irradiation of the excitation light a to the mark 9 is stopped and the detector 32 is operated at the same time, the afterglow b ′ emitted from the mark 9 is selectively detected by the detector 32. It is done.

On the other hand, in the embodiment of FIG. 16, the detection can be performed with the mark 9 stopped. That is, as shown in FIG. 16A, after the entire mark 9 to be detected is uniformly excited using the light emitting source 31, the light emitting source 31 is turned off as shown in FIG. The generated afterglow b ′ is input to the detector 32 via the lens 81. The detector 32 uses a one-dimensional or two-dimensional CCD element, converts and holds the intensity of the afterglow b ′ immediately after the light emitting source 31 is turned off in accordance with the magnitude of the electric signal S4, and then performs the next irradiation period. , The signal S4 previously held in series is extracted.

As long as the type of the substance constituting the mark 9 is a substance having a persistence property, a physical property such as a persistence wavelength or a persistence time is made to correspond to a purpose of use, and visible light is generated. The light source 31 can be changed.
Are also changed correspondingly. In addition, the present invention can be applied to a case where the emission center wavelengths of the excitation light a and the afterglow b 'are significantly different from each other. However, when the two wavelengths are close to each other or are the same, this is a particularly effective means. .

Further, if the mark 9 is formed by the phosphor layer 8 which is transparent and emits infrared light b and afterglow b 'upon irradiation with the excitation light a in the infrared region, the design 5 on the base material 4 The marks 9 can be formed overlapping without disturbing, and the effect for security is enhanced. The light source 31
The detector 32 and the detector 32 may be arranged in the traveling direction of the mark 9 in substantially the same manner as in the related art, or both light guides 43 and 46 may be combined into one to input and output light from the vertical direction of the phosphor layer 8. Good.

In each of the above-described embodiments, an example has been described in which the shape of the mark 9 is detected by using the afterglow b ′ of the phosphor layer 8. Of course, it can be implemented similarly.

[0066]

As described above, according to the present invention, the underlayer 7 for reflecting the excitation light a is provided on the back surface of the phosphor layer 8 on which a predetermined pattern is formed. The light emission state is ensured, and the occurrence of a detection error is prevented beforehand.

Further, the lower limit of the reflectance of the underlayer 7 is set so that the ratio of the light detection intensity obtained from the portion of the underlayer 7 and the portion of the phosphor layer 8 becomes a set multiple larger than 1 or more. By setting, the underlayer 7 and the phosphor layer 8 are clearly separated and detected, and the detection operation can be stabilized .

[0068]

Further, the irradiation with the excitation light a and the detection of the light emission b or the afterglow b ′ at the time of detection are performed by being inclined with respect to each other in a plane perpendicular to the direction in which the mark 9 moves. There is an excellent effect that the width of the scanning beam is prevented from expanding without requiring it, and the length of the mark 9 in the traveling direction can be accurately detected.

[Brief description of the drawings]

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

FIG. 2 is a graph showing the relationship between the thickness of a phosphor layer and the output voltage of a detector using the reflectance of an underlayer as a parameter.

FIG. 3 is a graph showing an example of a reflectance of a card surface measured by changing a wavelength of a light source.

FIG. 4 is a graph showing a relationship between an absorption rate of a phosphor layer and an output voltage of a detector.

FIG. 5 is a schematic diagram showing an example in which the present invention is applied to a card reader / writer.

FIG. 6 is a schematic diagram illustrating a mechanical configuration of a mark detection unit.

FIG. 7 is a schematic diagram illustrating an electrical configuration of a mark detection unit.

FIG. 8 is an exploded perspective view of a main part of the mark detection unit.

FIG. 9 is a plan view of a mark detection unit.

FIG. 10 is a sectional view taken along line XX of FIG. 9;

FIG. 11 is a waveform chart showing a procedure for detecting afterglow, and shows a case where the light-on time and the light-off time of the light emitting source are substantially equal.

FIG. 12 is an explanatory diagram illustrating an example of a mark detection procedure.

FIG. 13 is a waveform chart showing another embodiment of the afterglow detection procedure shown in FIG. 11, showing a case where the light-off time is shorter than the light-on time.

FIG. 14 is an explanatory diagram showing another embodiment of the mark detection unit, and shows an example in which a light emitting source and a detector are separated from each other in the mark transition direction.

FIG. 15 is an explanatory diagram showing still another embodiment of the mark detection unit, and shows an example in which the mark detection unit is disposed separately on both sides with a mark interposed therebetween.

FIG. 16 is an explanatory diagram showing still another embodiment of the mark detection unit, and shows an example in which a mark is detected while being stopped.

[Explanation of symbols]

 a excitation light b light emission b 'afterglow c reflected light 1 card 2 card reader / writer 4 base material 6 magnetic layer 7 underlayer 8 phosphor layer 9 mark 15 mark detection unit 17 card data processing unit 19 control unit 31 emission source 32 detection Container 42 light emitting element 43 light guide 44 light receiving element 45 optical filter 46 light guide

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tsutomu Yamaguchi 1-1-88 Ushitora, Ibaraki-shi, Osaka Hitachi Maxell Co., Ltd. (56) References JP-A-51-82109 (JP, A) JP-A-1 JP-A-197253 (JP, A) JP-A-57-90783 (JP, A) JP-A-61-217877 (JP, A) JP-A-60-83184 (JP, A) JP-A-1-301767 (JP, A) (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G06K 19/00-19/06 G06K 7/12

Claims (6)

(57) [Claims] 1. A formed pattern by thin-film phosphor layer (8), in response to the excitation light of the infrared region irradiated from front side (a), occurs to the light of different wavelengths in the infrared region <br /> a mark for detecting Ru, on the back side of the phosphor layer (8), the center of the excitation light (a)
Underlayer whose reflectance at wavelength is regulated to a value or more
(7) A detection mark formed by forming (7) . 2. The reflectance of the underlayer (7) is substantially uniform.
A is, illuminance of light was selectively detecting luminescence emitted from the phosphor layer (8) at the irradiation with the excitation light (a) is a base layer at substantially the same conditions (7) portion of the reflected light Selectively detect (c)
The reflectance of the underlayer (7) and the thickness of the phosphor layer (8) are set so that the illuminance of the reflected light is more than a set multiple larger than 1.
2. The detection mark according to claim 1, wherein 3. The reflectance of the underlayer (7) is non-uniform.
And the minimum value of the illuminance of light obtained by selectively detecting light emission emitted from the phosphor layer (8) upon irradiation with the excitation light (a) is:
The illuminance of the light obtained by selectively detecting the reflected light (c) of the base layer having the highest reflectance under substantially the same conditions is greater than 1
Reflection in the underlayer (7) so that it becomes a set multiple or more.
2. The detection mark according to claim 1 , wherein the minimum value of the ratio and the thickness of the phosphor layer are determined . (4)The mark according to claim 1 is detected.
Device for Relative to the mark (9) formed in the phosphor layer (8)
While irradiating the mark (9) with the excitation light (a)
Irradiation means; Irradiation with excitation light (a), which is disposed adjacent to the light irradiation means
Light detection means for selectively extracting light emitted from the position;
With The optical axes L1 and L2 of the light irradiation means and the light detection means are
On a plane orthogonal to the transition direction of
Mark detection device characterized by being arranged in a position . Claim 5.The mark (9) described above is replaced with the mark (9)
Formed in the shape of a narrow band extending parallel to and perpendicular to the transition direction of The light irradiating means has a predetermined length on the light emitting surface of the light emitting element (42).
Light guide (43) provided e, The light detecting means is provided on the light receiving surface of the light receiving element (44),
(A) via an optical filter (45) for blocking incidence
5. A light guide (46) connected thereto.
Mark detection device described . 6. The mark (9) cannot be rewritten.
Information for security, and is used by the phosphor layer (8).
I formed by printing on the card (1), said light irradiating means, correspond to the positions of formation of the phosphor layer (8)
Card (1) while irradiating the excitation light (a) in pulse form
While the light detecting means corresponds to each pulsed excitation light (a).
By checking the number of afterglow signals detected by
The width of the step (9) is determined.
Is a mark detection device according to 5.