JPS589476B2 - Paper sheet detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paper sheet detection device that optically detects paper sheets such as train tickets.

When separating valid tickets from fraudulent tickets using a paper sorting device, such as an automatic ticket gate, it is necessary to detect the shape, design, presence or absence of defects (tears, holes), etc. of the tickets. Based on the results of each detection, it is possible to distinguish between genuine and fraudulent tickets.

In this case, in order to continuously detect a plurality of types, it is common to use a plurality of combinations of light sources and light receivers.

However, for example, when the device must be installed within a predetermined size (the width of a ticket gate), such as an automatic ticket gate, the large size of the detection device is not practical.

Therefore, it is possible to use a common light source for each receiver, but this is good when performing detection by receiving direct light from the light source, but it is also possible to use a common light source for each receiver. When used to detect passing objects, it has the following drawbacks.

In other words, when detecting diffusely reflected light or diffusely transmitted light from paper sheets using indirect light from a light source, dust adheres to the diffuser plate used to diffuse the indirect light, reducing the amount of light received. Detection becomes uncertain.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a paper sheet detection device that can reliably detect paper sheets without dust or the like adhering to the paper sheets.

The invention will now be described according to the illustrated implementation.

The conveyance path 1 is composed of four belts 2a, 2b, 2c, and 2d.

Each of the belts 2a, 2b, 2c, and 2d is constructed by superimposing two belts, and the paper sheet 3 is conveyed while being held between these belts.

The conveyance path 1 has two step portions 4 and 5.

The stepped portions 4, 5 are formed by bending the belts 2a, 2b, 2c, 2d by rollers 6, 7, 8, 9, and the stepped portions 4, 5 are parallel to each other.

As shown in FIGS. 2 and 4, in the stepped portion 4, a diffusion plate 10 is disposed on the lower surface of the conveyance path 1 so as to overlap the conveyance path 1 with a small gap d therebetween.

This gap d is suitably 0.5 to 1 mm, for example.

On the other hand, a light source U is arranged on the conveyance path 1 so as to directly irradiate light onto the stepped portion 5 .

Therefore, the stepped portion 4 is irradiated with indirect light from the light source port.

The stepped portions 4 and 5 serve as detection positions for detecting the paper sheet 3 using diffusely reflected light and specularly reflected light, respectively, and each receives the diffusely reflected light from the paper sheet 3 with the stepped portion 4 as the detection position. A light receiver 12 is installed, and similarly a light receiver (not shown) is installed that receives specularly reflected light from the paper sheet 3 using the stepped portion 5 as a detection position.

The light receiver 12 is configured by being divided into a plurality of parts (or by combining a plurality of light receiving elements such as phototransistors) so as to receive diffusely reflected light from a predetermined area of the paper sheet 3.

Although not shown in FIG. 1, direct light irradiated from the light source U to the step 5 and diffusely reflected light due to indirect light irradiated from the light source port to the step 4 are reflected by the steps 4 and 5, respectively. A light receiver (not shown) and an optical system for focusing the light onto the light receiver 12 are installed.

This optical system includes an optical system 13 for direct light and an optical system 14 for indirect light, as shown in FIG. It is designed to be inserted between the

The optical systems 13 and 14 are removably installed in the direction of the arrow in FIG. 3 (direction perpendicular to the conveyance direction of the paper sheets 3).

The optical system 13 includes a cylindrical lens 17 placed on the light source U side,
It is composed of a cylindrical lens 18 (not shown) placed on the light receiver side, and light shielding plates 19 and 20 that are erected at the boundaries of each region of the cylindrical lenses 17 and 18.

The cylindrical lenses 17 and 18 are divided into a plurality of regions so as to collect specularly reflected light from a predetermined region of the paper sheet 3 and direct light from a light source port corresponding to each region.

Further, the optical system 14 also has a cylindrical lens 21 similar to the optical system 13.
and a light shielding plate 22 erected at the boundary of each area of this lens 21.

Next, the operation of the embodiment configured as described above will be explained.

In FIG. 1, paper sheets 3 are conveyed by a conveyance path 1 from the right end of the figure in the direction of the arrow.

First, the paper sheet 3 specularly reflects direct light emitted from the light source port at the stepped portion 5, and this specularly reflected light is received by a light receiver (not shown).

By comparing the output level from the light receiver at this time with a predetermined reference value, the reflectance of the paper sheet 3 can be detected.

For example, if the paper sheet 3 has reflectance characteristics averaged over its entire surface, if a highly reflective object is attached to a specific part of the surface of the paper sheet 3, then can be detected.

Next, the paper sheet 3 is conveyed to the step section 4, but before this, the indirect light from the light source 11 is reflected by the diffuser plate 10 as shown in FIGS. 2 and 4, and the diffused reflection The light is received by a light receiver 12.

The output of the light receiver 12 at this time is set as a reference value, and the output of the light receiver 12 when the paper sheet 3 is conveyed to the step section 4 is compared with the above reference value. It is possible to detect the shape, design, etc. of ordinary paper sheets3.
If the output of the light receiver 12 when receiving the diffusely reflected light from the paper sheet 3 is used as a reference value, it is possible to detect the presence or absence of defects (tears, notches, etc.) in the paper sheet 3 that has been conveyed.

The diffusion plates 10 are juxtaposed on the lower surface of the conveyance path 1 with a gap d as shown in FIG.

In general, paper sheets 3 generate dust when they come into contact with the conveyance path 1 or other devices during transportation, and
Dust may also enter from outside the device.

These dust particles adhere to the diffuser plate 10, and the amount of diffusely reflected light from the diffuser plate 10 is attenuated, making detection uncertain.

Therefore, if the diffuser plate 10 is arranged as shown in FIG. 4, when the paper sheet 3 is conveyed, wind will be generated in the vicinity, thereby making it possible to blow off the dust adhering to the diffuser plate 10.

Note that the gap d between the diffusion plate 10 and the conveyance path 1 is suitably 0.5 to 1 mm as described above.

This is because if the diffusion plate 10 comes into contact with the conveyance path 1, its surface will be damaged, and if it is too far away, it will be difficult to blow away the dust, and if the paper sheet 3 is actually irradiated, the light will be There is a possibility that different light may be incident.

The optical systems 13 and 14 are shown in FIGS. 3, 5, and 6, and are detachable in the direction of the arrow (see FIG. 3).

Therefore, maintenance and inspection of the optical systems 13, 14, the detection unit 15, etc. can be easily performed.

In the optical system 13, cylindrical lenses 17 and 18 are used as light shielding plates 19 and 20.
The specularly reflected light from the paper sheets 3 is detected and a light receiver (not shown) can receive the light for each predetermined region of the paper sheets 3.

Therefore, when performing detection by comparing the above-mentioned reference value with the output of the light receiver, it is performed for each region.

When detecting patterns, shapes, defects, etc. of the paper sheet 3, if the entire surface of the paper sheet 3 is optically scanned uniformly and point by point by the light source port and the light receiver, the paper sheet 3 is torn or wrinkled. Since there is a risk that the output may become unstable due to noise or the like, and the detection becomes uncertain, it is possible to extract the characteristics of a predetermined area of the paper sheet 3 by dividing and detecting each area. Therefore, extremely reliable detection can be performed.

Similarly, in the optical system 14, the cylindrical lens 21 is divided into predetermined regions, and a light shielding plate 22 is provided at the boundary of each region.

Therefore, it is possible to detect each area of the paper sheet 3,
Diffuse reflected lights incident on other areas do not affect each other.

As detailed above, the present invention has the following effects.

In other words, when a paper sheet or a diffuser plate is irradiated with indirect light from a light source, and the reflected light from the paper sheet or diffuser plate is received and detected, the amount of indirect light is small, so the amount of light that adheres to the diffuser plate is detected. Dust has a very strong effect on detection performance, but in the present invention, the diffusion plate is arranged parallel to the conveyance path with a predetermined gap, so that it is possible to prevent dust from adhering to the diffusion plate, thereby ensuring reliable detection. Can be done.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the present invention, Fig. 2 is an enlarged perspective view of the main parts shown in Fig. 1, Fig. 3 is a perspective view of the same example, and Fig. 4 is a main part of the same example. The front view, FIGS. 5 and 6 are perspective views of the optical system of the same example. 1... Conveyance path, 3... Paper sheets, 10... Diffusion plate,
11... Light source, 12... Light receiver, d... Gap.

Claims (1)

[Claims] 1 In a device that irradiates paper sheets with indirect light from a light source and receives reflected light from the paper sheets, there is a conveyance path for transporting paper sheets, a diffuser plate, and a device that irradiates the diffuser plate with the indirect light. and a light receiver that receives the light illuminated by the light source as diffusely reflected light through the diffusion plate, and the diffusion plate is connected to the conveyance path with a gap such that it does not come into contact with the conveyance path. A paper sheet detection device characterized by being arranged in parallel.