JPH0520512A - Detection mark and method and device for mark detection - Google Patents

Abstract

PURPOSE:To stably detect the form of a mark formed on a card while keeping a high measurement precision. CONSTITUTION:A mark 9 made of a phosphor layer 8 is formed on a foundation layer 7 where the lower limit value of the reflection factor is controlled. Exciting light emitted from a light source 42 is flicked and thrown to this formed mark 9, and the intensity of afterglow emitted from the mark 9 at the time of extinction of exciting light is detected by a detector 44, and the existence of the mark 9 in the position irradiated with exciting light is judged when this intensity is larger than a set value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to marks suitable for detection provided on various types of prepaid cards such as a pass ticket and a telephone card, a detection method for these marks, and a detection device for carrying out the detection method.

[0002]

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

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 for the phosphor are different, only the light emitted from the mark is selectively taken out by using an optical filter, A method of obtaining information is also disclosed (for example, Japanese Patent Laid-Open No. 53-9600).
(See the official gazette).

Further, by forming a mark such as a bar code formed of a photoluminescence layer using a phosphor that emits light in the infrared wavelength region on a printed matter such as a catalog, the content display of the printed matter such as the catalog is disturbed. Attempts have been made to obtain information such as the characteristics and prices of printed products without doing so (for example, Japanese Examined Patent Publication No.
22326, Japanese Patent Publication No. 61-18231).

[0005]

However, in the method for detecting a mark by utilizing the above-mentioned reflected light, when the information recording surface is soiled or damaged, the intensity of the reflected light is remarkably weakened and the information is erroneously read. There was an inconvenience.

On the other hand, in the method of detecting the mark by utilizing the light emission of the phosphor, although it is strong against the stain on the recording surface, the emission center wavelengths of the excitation light and the emission light are close to each other, so that both are completely removed. It is difficult to separate and detect, and there is a possibility that reflected light may be superimposed on detection light and detection accuracy may be reduced. Furthermore, it is known that the barcode formed by the phosphor layer formed on the printed matter as described above has a high probability of causing a reading error.

As a result of research conducted by the present inventors in order to investigate such a cause, the emission 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 was found that the reading error of the mark 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 the underlayer 7 further has a wavelength of, for example, 800 nm. An optical filter 45 for forming a mark 9 such as a bar code and blocking the excitation light a is formed by a phosphor layer 8 which generates a light b of 1000 nm different from the wavelength of the excitation light a upon incidence of the excitation light a. 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, the base material 4 itself is used as the underlayer 7 (the reflectance at the excitation light wavelength is about 78%), the white underlayer B containing titanium oxide powder (the same reflection) The reflectance was about 39%), the silver-colored underlayer C containing aluminum powder (the reflectance was about 34%), and the black underlayer D containing magnetic powder (the reflectance was 5%). FIG. 2 shows the result of measuring the voltage value output from the light detecting means by forming the phosphor layer 8 on each base layer 7 by changing the film thickness from 0 to 200 μm.

When 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 a problem, but the light emitted by the excitation light a is emitted. When b is directly used for detection, the ratio of the output voltage between the part of the base layer 7 alone and the part where the phosphor layer 8 is provided becomes a problem. Since the degree is necessary, it is the group of straight lines A ′ to D ′ that shows the lower limit value for each of the underlayers A to D.

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

On the other hand, when the underlying layer 7 has a partially different reflectance such as a design printing surface, the thickness of the phosphor layer 8 to be formed is 10 μm, and the portion having the highest reflectance is the underlying layer A. Assuming that, in order to detect the reflection on the underlayer 7 and the light emission from the phosphor layer 8 separately, it is necessary to fall within the output voltage range v of A ′ or higher. Although the underlayer B meets this condition, it is not suitable for the underlayer C, and it is understood that the reflectance needs to be regulated to about 39% or more which is the reflectance of the underlayer B.

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

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

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

The present invention utilizes the knowledge based on the above-mentioned experiments, and an object thereof is to provide a detection mark in which the detection error is reduced as much as possible. It is another object of the present invention to provide a detection mark that improves detection accuracy when the mark is formed on a portion of the underlayer where the reflectance is not uniform.

Another object of the present invention is to provide a mark detecting method which can detect marks with a relatively simple structure and with high accuracy. Still another object of the present invention is to provide a mark detecting device capable of accurately detecting a mark formed in a bar code shape.

[0018]

The detection mark 9 according to the present invention has a pattern formed by a thin film phosphor layer 8 as shown in the basic structure of FIG. 1, and is irradiated from the front side. An underlayer 7 that emits light b or afterglow b of a wavelength different from that of the excitation light a and that reflects the excitation light a is formed on the back side of the phosphor layer 8 described above. It is characterized by

When the above-mentioned phosphor layer 8 is formed on the base layer 7 having a uniform reflectance, the thickness is 0.5 to 20.
In addition to selecting from the range of 0 μm, the voltage value obtained by selectively detecting the light emission b emitted from the phosphor layer 8 and performing photoelectric conversion detects the reflected light c of the base layer 7 portion under substantially the same conditions. So that it is about 1.6 times the voltage value photoelectrically converted,
It is preferable to set the reflectance of the underlayer 7.

When the phosphor layer 8 is formed on the base layer 7 having a non-uniform reflectance, the film thickness is 0.5 to 200 μm.
And the lowest value of the voltage value obtained by photoelectrically converting the light emission b emitted from the phosphor layer 8 by selectively detecting the light emission b from the phosphor layer 8 and having the highest reflectance under substantially the same conditions. It is preferable to set the reflectance of the underlayer 7 so that it is about 1.6 times or more of the voltage value obtained by detecting the reflected light and photoelectrically converting the reflected light.

In the mark detecting method according to the present invention, a step of irradiating the mark 9 formed of a substance having afterglow property with the excitation light a, and the mark 9 irradiated with the excitation light a are emitted. And a step of separating and detecting the afterglow b ′.

It is possible to intermittently extinguish the excitation light a irradiating the mark 9 while detecting the afterglow b'in conjunction with the extinguishing period of the excitation light a.
The turn-off time T2 of the excitation light a is preferably shorter than the turn-on time T1. Further, the irradiation process of the excitation light a and the detection process of the afterglow b ′ described above may be performed while being shielded from each other, and the mark 9 may be moved from the irradiation side to the detection side.

On the other hand, the mark detecting device according to the present invention is
While moving relative to the mark 9 formed on the phosphor layer 8,
Light irradiating means for irradiating the mark 9 with the excitation light a, and light which is disposed adjacent to the light irradiating means and selectively extracts the light b or b ′ emitted from the focal position f of the excitation light a. And a detection means. It is characterized in that 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 the xy plane orthogonal to the mark 9 when the transition direction of the mark 9 is z. .

The above-mentioned mark 9 is formed in a strip shape extending in parallel to the direction x orthogonal to the transition direction z of the mark 9, and the phosphor layer 8 constituting the mark 9 is formed.
By irradiating the excitation light a in the infrared region, it is possible to generate the light b in the infrared region different from the central wavelength of the excitation light a, while the light irradiating means has a light guide 43 of a predetermined length on the light emitting surface of the light emitting element 42.
It is preferable that the light detection means is connected to the light receiving surface of the light receiving element 44 through the optical filter 45 that blocks the incidence of the excitation light a.

[0025]

In the above structure, by providing the underlayer 7 on the back side of the phosphor layer 8, the intensity of the emitted light b or the afterglow b ′ emitted from the phosphor layer 8 when the excitation light a is irradiated is maintained sufficiently high. To be done.

Further, the reflectance of the underlayer 7 is uniform, and the reflected light c at the underlayer 7 portion and the intensity of the light emission b at the phosphor layer 8 portion are about 1.6 at the stage after photoelectric conversion. By maintaining the value of twice or more, the boundary portion between the base layer 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 reflectance, it is formed on another underlayer portion having a lower reflectance than the reflected light intensity of the underlayer portion having the highest reflectance. The underlayer 7 is formed so that the emission intensity output from the phosphor layer 8 is maintained at about 1.6 times or more in the photoelectrically converted state.
By setting the reflectance of the phosphor layer 8, the output variation of the emission intensity from the phosphor layer 8 due to the variation of the reflectance of the underlayer 7
It is prevented from being mistakenly recognized as the boundary between the mark 9 and the base layer 7.

On the other hand, when the mark 9 having the afterglow property is irradiated with the excitation light a to be excited and then the irradiation of the excitation light a is forcibly stopped or moved from the irradiation position, the excitation light a
Of the afterglow component b ′ of the mark 9
Emitted from above. Therefore, by detecting the afterglow b ′, a signal corresponding to the formation position of the mark 9 is selectively extracted regardless of whether the emission center wavelengths of the excitation light a and the afterglow b ′ are close to each other. It is done.

Further, in the above-mentioned mark 9 detection device, when the control means sends a control signal to the light irradiation means, the irradiation 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 extending direction of the mark 9, and the focal positions f of the both 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 being emitted from the light irradiation means is restricted, and the resolution along the transition direction of the mark 9 is kept high.

[0030]

EXAMPLES The present invention will now be described more specifically based on an example in which the card 1 on which arbitrary data is recorded and the card reader / writer 2 shown in FIG. 5 for processing the data recorded on the card 1 are implemented. explain.

[0031]

[Card] As shown in FIGS. 7 and 8, the card 1 is a white polyester containing a white pigment having a length of about 5.5 cm and a width of about 8.5 cm as a base material 4 and a thickness of about 188 μm. Using a film, the design 5 is printed on the upper surface side of the base material 4 and the magnetic paint is applied on the lower surface side of the base material 4 in the same manner as in the prior art, so that the main information is rewritably recorded. Forming layer 6.

According to the present invention, in addition to the above-mentioned 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 feature is that sub-information for security can be fixed.

For the underlayer 7, for example, 50 parts by weight of aluminum powder, 50 parts by weight of a polyester resin (Vylon 280 manufactured by Toyobo Co., Ltd.), and 200 parts by weight of methyl ethyl ketone are mixed and dispersed in a ball mill for 48 hours. After adjusting the coating material for the ground layer, the entire surface of the magnetic layer 6 is coated and dried to form a uniform underlayer 7 having a thickness of about 4 μm.
Was formed.

Marks 9 formed on the underlayer 7 described above
As shown in FIG. 1, the phosphor layer 8 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 mark 9 is used to record predetermined security sub-information such as a card issuing store code or a personal identification number on the card 1. is doing.

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

Specifically, Li (NdO.9YbO.1) P4O1
It is formed by screen-printing a fluorescent paint containing a fluorescent substance such as 2 and further has a wavelength of 800 nm, for example.
When irradiated with excitation light a in the near infrared region in the vicinity, 1000 n
Even if the infrared light b having a peak value at a wavelength near m is generated and the light irradiation is stopped, as shown in FIG.
The decay time of 90 to 10% is configured to generate the afterglow b ′ of 400 to 600 μs.

The content of the phosphor powder in the phosphor layer 8 is such that the emission b of sufficient intensity when irradiated with the excitation light a.
To obtain a weight ratio of 1: 2 to the binder resin.
It is preferably within the range of 2: 1.

The thickness of the phosphor layer 8 is 0.5 μm-2.
The thickness is selected from the range of 00 μm, but is preferably 1 μm or more in order to obtain a sufficiently stable output, and is 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. 2, the card reader / writer main body 10 includes a portable personal computer 11 that sends necessary data to the card reader / writer main body 10, and a printer 12 that displays the writing state of the card 1.

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

The card reader / writer main body 10 is provided with a one-chip microcomputer for control and operates independently based on the received information, and is composed of a plurality of stacked cards 1.1. A card supply unit 14 that takes out cards one by one, and a mark detection unit 1 that determines whether the card is good or bad by reading the sub information of the card 1 taken out from the supply unit 14.
5, a defective card ejecting unit 16 for ejecting a card determined to be defective by the detecting unit 15, a card data processing unit 17 for reading / writing main information of the card 1, and ejecting the card 1 in which the main information is written. The card storage unit 18 and the control unit 19 that sends a control signal to each of the above units.

As shown in FIG. 6, the card supply unit 14 has the card 1 accumulated on the upper portion of the guide frame 20 in which the cards 1 are accommodated in a horizontal state with the surface on which the mark 9 is formed facing downward. A counterweight 21 that applies a predetermined pressing force in the vertical direction from above is swingably provided in the vertical direction, while it is provided with card discharge rollers 23 and 24 slightly protruding from the bottom wall 22 of the guide frame 20 and guides. Front 25 of frame 20
On the same side as the bottom wall 22 on the side, a slit 26 through which only one card 1 can pass is provided for fine adjustment. Further, the card discharge roller 23 on the slit 26 side is provided with the roller 2
The drive motor 27 of No. 3 is provided, and the motor 27 is rotationally driven in conjunction with the input of the drive signal from the control unit 19, so that the lowermost card 1 in contact with the roller 23 is slit.
It is slid to the 6 side, and the cards 1 are fed one by one toward the mark detecting section 15 with the surface on which the marks 9 are formed facing downward.

[0043]

[Mark Detection Unit] The present invention is characterized by the structure of the mark detection unit 15. As shown in the schematic overall structure of FIGS. The traveling unit 30 that is horizontally moved downward and a light emitting source 31 that is disposed below the card traveling surface and intermittently irradiates the mark 9 on the card 1 with the excitation light a, and the light emitting source 31 is turned off. A detection head 33 in which a detector 32 for detecting the afterglow b ′ emitted from the mark 9 is integrally housed,
Detection circuit 34 for processing the signal output from the detector 32
It has and.

The running portion 30 of the card 1 is shown in FIGS.
As shown in FIG. 3, guide rails 35, 35 for horizontally supporting both side edges of the card 1 are fixed in parallel along both sides of the traveling path, and a drive roller 37 rotated by a motor 36.
.38 and pressing rollers 39 and 40 for applying a pressing force to the card 1 from above the rollers 37 and 38 are set as one set, and one set is provided for each of the entrance and exit portions 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 is sent from the card supply unit 14, the motor 36 is rotated in the normal direction,
Is horizontally moved at a constant speed of about 200 to 400 mm per second, and the bar code-like mark 9 formed of the phosphor layer 8 on the lower surface side of the card 1 sequentially passes over the light emitting source 31 and the detector 32. I am doing it.

As shown in FIGS. 9 and 10, the light-emitting source 31 has a diameter of 3.0 mm and a long length at a light-emitting portion of a light-emitting element 42 such as a light-emitting diode which emits near infrared rays having an emission center wavelength of around 800 nm. A light guide 43 made of glass fiber having a size of about 7.0 mm is attached. The front end 43a of the light guide 43 is brought closer to the surface of the card 1 by a distance of 2 mm or less, and the entire light guide 43 is placed on a plane orthogonal to the moving direction of the mark 9 and 45 from the horizontal direction. It is arranged with an inclination angle α of up to 60 °. Further, according to the signal S1 output from the control unit 19, the light emitting element 42 has a lighting time T1 and a light-off time T2 at approximately equal time intervals of 500 μsec corresponding to the driving period of the motor 36, as shown in FIG. Is turned on and off so that the mark 9 is intermittently irradiated with the excitation light a.

The detector 32 has an optical filter 45 for selectively passing the afterglow b ′ generated from the mark 9 on the light receiving surface of a light receiving element 44 such as a photocell having a light receiving sensitivity in the infrared region. A light guide 46, which is substantially the same as the light emitting source 31 side, is fixed, and after being converted into an electric signal S2 corresponding to 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 the single light irradiation and the afterglow detection operation are performed in a stopped state. Can be regarded as Therefore, the tip end 46a of the light guide 46 on the detector 32 side is made to be adjacent to the tip end 43a of the light guide 43 on the light emission source 31 side, and is inclined at 105 to 115 ° on the plane orthogonal to the above-described transfer 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 from the direction perpendicular to the surface of the mark 9 as much 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.
By covering with the cover 48 having the slit 47 on the narrow band as shown in FIG. 2, the width of the light beam in the width direction of the mark 9 in the excitation light a emitted from the light emission source 31 is limited, and at the same time, the mark for the detector 32 is formed. By also limiting the light input in the width direction of the mark 9, the detection accuracy of the mark 9 is improved.

Further, by raising a portion of the light emitting source 31 in the vicinity of the light guide tip end 43a to a slightly upward direction, the raised portion 5 is formed.
2 is brought into contact with the lower surface side 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 was started, the intensity of the signal S2 input to 4 could not be blocked by the optical filter 45 with respect to the light emission b emitted from the phosphor layer 8 as shown in FIG. 11 (b). The reflection component c of the excitation light a is superimposed and rises, but when the irradiation of the excitation light a is stopped, the afterglow b ′ emitted from the phosphor layer 8
It only decreases exponentially. Therefore, the output signal S
2 is input to the comparison circuit 50 that operates corresponding to the extinguishing period of the light emitting element 42 and compared with the set value Vs,
A rectangular wave signal S3 is formed corresponding to the position where the mark 9 is formed 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 / absence of the rectangular wave signal S3 immediately after each turning off of the light emitting element 42.
As shown in 2 (d), the widths of the marks 9 in the running direction of the card 1 are sequentially detected by integrating the numbers of the rectangular wave signals S3 that are continuously input. Further, the detection data is decoded by comparing the pattern obtained from each width detected as described above with the bar code pattern stored in advance, and at the same time the decoding result is displayed on the display unit 52. , If the detected data is correct, the motor 3
The normal rotation operation of No. 6 is continued and sent to the card data processing unit 17. However, if it is detected that the data is not correct, or if the data itself is not detected,
The motor 36 in the running unit 30 is reversely rotated to send the card 1 to the defective card discharge unit 16.

The defective card ejecting section 16 is provided in the card supplying section 1.
4 is provided with a non-return roller 55 which 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
The card 1 reversely run from the above is discharged to the receiving portion 56 side by the non-return roller 55 and the guide rail base end 35a.

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

[0053]

[Other Embodiments] FIG. 13 is a waveform diagram showing another embodiment of the afterglow detection procedure shown in FIG. In the present embodiment, as shown in FIG. 13A, as the lighting time T1 of the light emitting element 42, the time necessary for exciting the phosphor layer 8 forming the mark 9 is maintained, while the extinguishing time is maintained. T2
As a result, the excitation light a output from the light emitting element 42 is limited to the minimum time required to detect the afterglow b ′.
Is made as short as possible, the number of pulses of the signal S3 detected while scanning one mark 9 is increased, and the accuracy of mark width measurement can be improved.

Also in this embodiment, the detection signal S corresponding to the light emission from the phosphor layer 8 shown 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 in which the set value is exceeded. However, in the present embodiment, FIG.
As shown in (d), a gate time T4 for detecting afterglow in which detection margins T3 and T5 are provided in the front and rear in the approximate center of the turn-off time T2.
Is set and the logical product with the above-mentioned FIG. 13 (c) is taken to generate the signal S3 as shown in FIG. 13 (e).

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

From these results, the SN ratio at time t2 at the time of afterglow detection was about 60 dB, whereas the SN ratio at the time t1 at the time of light emission detection remained at about 13 dB, and the afterglow detection should be performed. It was confirmed that the SN ratio was significantly improved by the above.

FIG. 14 shows another embodiment of the mark detecting section 15 described above, in which a light emitting source 31 is provided at an upstream position in the moving direction of the mark 9 formed of the phosphor layer 8 while a detector 32 is provided at the downstream side. In addition to the above, the partition wall 80 shields the two from each other.

With this structure, 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. 14B.
As for the afterglow b ′, only the afterglow b ′ generated from a position facing the detector 32 is selectively incident on the detector 32 through a slit 47 a provided in the partition wall 80 as shown in FIG. 14C. The detection operation is performed in substantially the same manner as in the above embodiment.

In this structure, the mark 9 is formed by using a phosphor having a long afterglow time, or a phosphor having a short afterglow time is used, but the traveling speed of the mark 9 is sufficiently high. The configuration is effective when the mark 9 has a sufficient afterglow 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 as in the case of manually moving the mark 9, the detectors shown in FIGS. 1 and 14 are provided at the same time to detect the detected operation. The detector 32 can be switched and used depending on the speed.

FIG. 15 and FIG. 16 are still another embodiment. In the embodiment of FIG. 15, the light emitting source 31 and the detector 32 are separately arranged vertically with the mark 9 as the center. At least a part of the base material 4 on which the mark 9 is provided has a light-transmitting property, and the mark 9 is formed there. With such a configuration, as shown in FIG.
The excitation light a emitted from the laser light 1 passes through the substrate 4 and is applied to the mark 9, and the phosphor layer 8 forming 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. Is done.

On the other hand, in the embodiment shown in FIG. 16, the mark 9 can be detected while the mark 9 is stopped. That is, as shown in FIG. 16A, after the entire mark 9 to be detected is uniformly excited by 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. As the detector 32, a one-dimensional or two-dimensional CCD element is used, and after the intensity of the afterglow b ′ immediately after the light emission source 31 is turned off is converted and held according to the magnitude of the electric signal S4, the next irradiation period Corresponding to, the signal S4 previously held in the serial state is taken out.

If the kind of the material forming the mark 9 has an afterglow property, the visible light is generated by making physical characteristics such as the wavelength of the afterglow or the afterglow time correspond to the purpose of use. You can change it to something that makes you shine.
The emission wavelength of is also changed correspondingly. Further, the present invention can be implemented when the emission center wavelengths of the excitation light a and the afterglow b ′ are significantly different, but when both wavelengths are close or the same, it becomes a particularly effective means. .

Further, if the mark 9 is formed by the phosphor layer 8 which is transparent and emits the infrared emission b and the afterglow b ′ upon irradiation with the excitation light a in the infrared region, the design 5 on the substrate 4 can be obtained. The marks 9 can be formed in an overlapping manner without disturbing, and the effect for security is enhanced. In addition, the light source 31
The detector 32 and the detector 32 may be arranged in the advancing direction of the mark 9 in the same manner as in the conventional case, or the light guides 43 and 46 of both may be combined into one to input and output light in the vertical direction of the phosphor layer 8. Good.

In each of the above embodiments, the shape of the mark 9 is detected by utilizing the afterglow b'of the phosphor layer 8, but the shape of the mark 9 is also detected. Of course, the same can be done.

[0066]

As described above, according to the present invention, since the underlayer 7 for reflecting the excitation light a is provided on the back surface side of the phosphor layer 8 on which the predetermined pattern is formed, the mark 9 always has a sufficiently large intensity. The light emission state is secured, and the occurrence of detection error is prevented in advance.

Further, by setting the lower limit value of the reflectance of the underlayer 7 so that the ratio of the detection voltage obtained from the underlayer 7 and the phosphor layer 8 is always 1.6 times or more. ,
The base layer 7 portion and the phosphor layer 8 portion are clearly separated and detected, and the detection operation can be stabilized. Furthermore, mark 9
By using the afterglow b ′ output from the detection of the mark 9, the influence of the excitation light a disappears,
Detection with a high SN ratio is performed.

Furthermore, the afterglow b ′ is detected by blinking the excitation light a at high speed, or the extinction time T2 of the light emitting element 42 during the afterglow detection is made shorter than the lighting time T1. The detection operation can be performed in a state where there is little attenuation of ', and the false detection is prevented as much as possible because almost the same place overlaps as the detection target, and the pulse rate of the detection signal S3 is increased to improve the detection accuracy. Is planned.

Further, the irradiation of the excitation light a and the detection of the light emission b or the afterglow b ′ at the time of detection are performed by inclining each other in a plane orthogonal to the moving direction of the mark 9, so that narrowing by the slit is particularly effective. It is possible to suppress the expansion of the width of the scanning beam without needing it, and it is possible to accurately detect the length of the mark 9 in the traveling direction.

[Brief description of 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 film thickness of the phosphor layer and the output voltage of the detector with the reflectance of the underlayer as a parameter.

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

FIG. 4 is a graph showing the relationship between the absorptance of the phosphor layer and the output voltage of the detector.

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

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

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

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

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

10 is a cross-sectional view taken along line XX of FIG.

FIG. 11 is a waveform diagram showing a procedure for detecting afterglow, showing a case where the lighting time and the extinction time of the light emitting source are substantially equal to each other.

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

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

FIG. 14 is an explanatory diagram showing another embodiment of the mark detecting section, showing an example in which a light emitting source and a detector are arranged separately in the mark transition direction.

FIG. 15 is an explanatory view showing still another embodiment of the mark detection unit, showing an example in which the mark is sandwiched and separated on both sides.

FIG. 16 is an explanatory diagram showing still another embodiment of the mark detection unit, showing an example of detecting a mark while it is stopped.

[Explanation of symbols]

a excitation light b light emission b'afterglow c reflected light 1 card 2 Card reader / writer 4 base materials 6 Magnetic layer 7 Underlayer 8 Phosphor layer 9 mark 15 Mark detector 17 Card data processing unit 19 Control unit 31 light source 32 detectors 42 light emitting element 43 light guide 44 Light receiving element 45 Optical filter 46 light guide

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tsutomu Yamaguchi             Hitachi Ma, 1-88, Torora, Ibaraki City, Osaka Prefecture             Within Kucsel Co., Ltd.

Claims (11)

[Claims] 1. A detection mark, which has a pattern formed of a thin-film phosphor layer (8) and emits light of a different wavelength corresponding to the excitation light (a) irradiated from the front side. A detection mark characterized in that an underlayer (7) reflecting a) is formed on the back side of the phosphor layer (8). 2. The phosphor layer (8) has a thickness selected from the range of 0.5 to 200 μm, and
It is formed on the underlayer (7) having a uniform reflectance, and the voltage value obtained by photoelectrically converting the light emitted from the phosphor layer (8) selectively and photoelectrically converting the underlayer (7) is substantially the same. The reflectance of the underlayer (7) is set so that the reflected light (c) of the portion (7) is detected and photoelectrically converted to about 1.6 times or more. Detection mark. 3. The above-mentioned phosphor layer (8) has a thickness selected from the range of 0.5 to 200 μm, and
It is formed on the underlayer (7) having a non-uniform reflectance, and further, the minimum value of the voltage value obtained by photoelectrically converting the light emission emitted from the phosphor layer (8) by selectively detecting it is substantially the same. The reflectance of the underlayer (7) is set so as to be about 1.6 times or more of the voltage value obtained by photoelectrically converting the reflected light (c) of the underlayer having the highest reflectance in the above. The detection mark according to claim 1. 4. A step of irradiating the mark (9) formed of a substance having afterglow property with the excitation light (a), and a residue emitted from the mark (9) irradiated with the excitation light (a). And a step of separating and detecting only light (b ′). 5. The excitation light (a) applied to the mark (9) is turned off intermittently, and the afterglow (b ′) of the excitation light (a) is interlocked with the turning-off period of the excitation light (a). The mark detection method according to claim 4, wherein a detection operation is performed. 6. The mark detecting method according to claim 5, wherein the turn-off time T2 of the excitation light (a) is shorter than the turn-on time T1. 7. The mark (9) is non-rewritable security information, which is printed and formed on the card (1) by the phosphor layer (8), and the mark (9) of the phosphor layer (8) is formed. The card (1) is moved while irradiating the excitation light (a) in a pulsed manner corresponding to the formation position, and the afterglow (b ′) detected corresponding to each pulsed excitation light (a) The mark detection method according to claim 5, wherein the width of the phosphor layer (8) is determined by checking the number of signals. 8. The step of irradiating the excitation light (a) and the step of detecting the afterglow (b ′) are performed while being shielded from each other, and the mark (9) includes the excitation light (a). ) Afterglow from the irradiation side (b ')
The mark detection method according to claim 4, wherein the mark detection method is moved toward the detection side of the mark. 9. The material for forming the above-mentioned mark (9) emits near-infrared light (b ′) when excited by near-infrared light (a). Mark detection method described. 10. Light irradiation means for irradiating the mark (9) with excitation light (a) while moving relative to the mark (9) formed of the phosphor layer (8), and the light irradiation means. A mark detecting device, which is arranged adjacent to each other and has a light detecting means for selectively extracting light (b, b ') emitted from an irradiation position (f) of excitation light (a), A mark detecting device characterized in that the optical axes L1 and L2 of the light detecting means and the light detecting means are arranged to be inclined with respect to each other on a plane orthogonal to the transfer direction of the mark (9). 11. The mark (9) described above is formed into a strip shape extending in parallel to the transition direction of the mark (9), and a phosphor layer (8) constituting the mark (9) is formed. Irradiation with the excitation light (a) in the infrared region makes it possible to generate light (b · b ′) in the infrared region different from the central wavelength of the excitation light (a), and the light irradiation means is a light emitting element (42). A light guide (43) of a predetermined length is provided on the light emitting surface of the light detecting means, and the light detecting means uses the optical filter (45) that blocks the excitation light (a) from entering the light receiving surface of the light receiving element (44). A guide (46) is connected to the guide (1).
0 mark detection device.