JPH09138876A - Media transport device - Google Patents

Abstract

(57) Abstract: By configuring the detection area of a medium detection means for detecting a medium in a narrow direction, the ratio of the medium to the detection area at the time of medium detection is relatively increased to a predetermined value. It is possible to accurately detect the medium that has reached the position, and when capturing an image of the medium with an image pickup means such as a CCD camera, it is possible to obtain a timing signal for image acquisition without deviation, and from the screen of the medium image. It is an object of the present invention to provide a medium carrying device capable of preventing the medium from protruding. A medium transport device for transporting a medium A, the medium transporting means 18 transporting the medium A by placing it on an upper surface.
And medium detection means 24 for detecting that the medium A has reached a predetermined position, and detection area regulation means 23 for regulating the detection area of the medium detection means 24 in the narrow direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium conveying device for picking up an image of a medium such as coins conveyed on a belt by a CCD camera image pickup means.

[0002]

2. Description of the Related Art Conventionally, as a medium conveying device of the above-mentioned example, there is a device shown in a plan view in FIG. That is, a belt 91 that travels approximately in the center of the upper surface of the base member 90 is provided, and a coin B as a medium is placed and conveyed on the upper surface of the belt 91, and the coin B is used for denomination determination.
A transmission type sensor 9 including a light projector 92 and a light receiver 93 as shown in the figure for the purpose of obtaining a timing signal for image acquisition necessary when a CCD camera (not shown) captures the pattern
4 is a device arranged in the lateral direction.

However, in the transmissive sensor 94, the light beam 92a of the projector 92 generally expands as shown in FIG. 11, and the light receiving area 93a on the side of the light receiver 93 also has a predetermined range. When the medium is the coin B, the thickness of the coin B becomes smaller than that of the light receiving area 93a as shown in FIG. For this reason, the light-receiving area 93a is shielded by the coin B only in a part thereof, and the difference between when the light-receiving amount of the sensor 94 is transmitted and when it is shielded is small.

While the tip of the coin B is in the light receiving area 93a of the sensor 94 while advancing in the advancing direction, the light shielding area changes according to the position of the coin B, so that the sensor light receiving amount gradually changes as shown in FIG. To do. Since this light reception signal has a small change level and is a gradual change, the edge position of the binarized digital signal (see the binarized signal) is indicated by an arrow in FIG. 12 when there is a disturbance such as noise. It tends to fluctuate. Since the position of the coin B cannot be accurately detected in this way and the reference timing for image acquisition is delayed, there is a problem that the medium image sticks out from the screen imaged.

[0005]

SUMMARY OF THE INVENTION According to the present invention, the ratio of the medium to the detection area at the time of detecting the medium is relatively increased by configuring the detection area of the medium detecting means for detecting the medium in the narrow direction. Then, the medium which has reached the predetermined position can be accurately detected, and when the medium is imaged by an image pickup means such as a CCD camera, a timing signal for image acquisition without deviation can be obtained. An object of the present invention is to provide a medium carrying device that can prevent an image from protruding from the screen.

[0006]

SUMMARY OF THE INVENTION The present invention is a medium transporting device for transporting a medium, the medium transporting means for transporting a medium placed on an upper surface thereof, and detecting that the medium has reached a predetermined position. It is characterized in that it is a medium conveying device provided with a medium detection means and a detection area regulation means for regulating the detection area of the medium detection means in a narrow direction.

[0007]

According to the present invention, the medium carrying means carries the medium on its upper surface and carries it, and the medium detecting means detects that the medium has reached a predetermined position. The regulation unit regulates the detection area of the medium detection unit in the narrow direction. Therefore, the ratio of the medium to the detection area at the time of detecting the medium is relatively increased, so that the change level of the medium detection signal from the medium detection unit becomes large and the medium reaching the predetermined position can be accurately detected. effective. Further, when an image of a medium is picked up by an image pickup means such as a CCD camera, it is possible to obtain a timing signal for image acquisition without deviation and prevent the medium image from protruding from the screen.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawing shows a coin processing device equipped with the medium conveying device of the present invention. In FIG. 1, the coin processing device 11 comprises a supply belt conveyor 15 in which an endless supply belt 14 is stretched between rollers 12 and 13. At the same time, the endless transfer belt 18 is stretched between the rollers 16 and 17 so that the transfer surface of the coin A as the medium is located in the same plane as the transfer surface of the supply belt 14, and the transfer belt conveyor 19 Are configured.

The above-mentioned transport belt 18 has a coin A on its upper surface.
An accelerating roller 20 as an accelerating means for accelerating the coin A is provided on the conveying start end side of the conveying belt 18, which is a medium conveying means for carrying and conveying the medium.
The above-mentioned acceleration roller 20 has an annular recess 20a at the center in the width direction of conveyance as shown in FIGS. 2, 3 and 4, and when the coin A passes through the acceleration roller 20, the acceleration roller 20 of this coin A
The contact points p1 and p2 that finally come into contact with each other are two points as shown in FIG. 4, and have the effect of preventing the coin A from rising and bouncing.

By the way, in FIG. 1, the moving speed of the coin A by the supply belt 14 is set to V, and the acceleration roller 20 described above is used.
Then, it is configured to accelerate the moving speed of the coin A to n times (where n ≧ 1). Then, the coin A continuously sent at the speed V is first transferred to the preceding coin A by the acceleration roller 20.
It is accelerated twice. By the time the rear coin A reaches the acceleration roller 20, it is necessary to advance the length L of the front coin A. On the other hand, while the rear coin A advances by the length L, the front coin A travels n times (that is, nL) the distance of the rear coin A. Therefore, the distance D (see FIG. 1) between the leading coin A and the trailing coin A is n · L−L = (n−
1) · L, and if a coin A having a diameter of 20 mm is continuously conveyed and is accelerated by the acceleration roller 20 by n = 3 times, D = (n−1) · L = (3 -1) A space of 20 = 40 mm will be opened, and the formation of this space D will ensure the individual separation of the coin A, so that the entire surface (that is, the upper surface) of each coin A can be captured satisfactorily. Is configured.

Further, behind the above-mentioned acceleration roller 20 (on the right side in FIG. 1), there is provided a restriction member 21 as a restriction means for restricting the attitude of the coin A passing through the acceleration roller 20,
The restriction member 21 is configured to prevent the behavior of the coin A. On the other hand, above the conveyor belt 18 behind the above-mentioned regulation member 21, CC as a medium imaging means for imaging the entire surface of the coin A being conveyed by the conveyor belt 18.
A D camera 22 (imaging camera) is provided.

FIG. 5 is a block diagram of a control circuit of the coin processing apparatus, in which a transmissive sensor 24 including a light emitter and a light receiver is arranged as a medium detecting means in the left and right lateral directions orthogonal to the conveyor belt 18 on the base 23. , CCD camera 2 mentioned above
An A / D converter 25 and an image memory 26 are connected to the next stage of 2. Further, illumination lamps 27, 27 are provided as illumination means for the purpose of illuminating the coin A at the photographing position.

Thus, the CPU 30 receives the RO from the transmission type sensor 24 acting as a trigger sensor and the input from the image memory 26 connected to the next stage of the CCD camera 22.
Output device 31 according to the program stored in M28
And the CCD camera 22 are driven and controlled, and the RAM 29
Stores the necessary tables and data such as the characteristic data on the front and back sides of the correct coin and the rule for extracting the characteristic.

Here, the light receiving area 24a of the light receiver in the above-mentioned transmission type sensor 24 is shielded to half of the conventional light receiving area 93a of FIG. 12 by providing the base 23 as the detection area regulating means as shown in FIG. It is set. With this configuration, the difference level of the received light between when the light is transmitted and when the light is blocked is shown in FIG.
This is twice as large as that of the configuration of No. 2, and the binarized signal has a small fluctuation in the edge position. The operation of the coin processing device thus configured will be described in detail below with reference to the side view shown in FIG. 1 and the flowchart shown in FIG.

From the supply belt conveyor 15 on the upstream side to the conveyor belt 18 of the conveyor belt conveyor 19 and the acceleration roller 20.
The coin A supplied in between is accelerated by the acceleration roller 20 and sent out. When the coin A passes through the acceleration roller 20, the contact points p1 and p2 at which the coin A finally contacts the acceleration roller 20 are two points as shown in FIG.
Since the coin A is prevented from floating and bouncing up and the behavior of the coin A is blocked by the restriction member 21 provided behind the acceleration roller 20, the coin A to be imaged is separated from the succeeding coin A by a distance D. Moreover, it is conveyed in a stable posture.

The coin A thus separated and conveyed in a stable posture reaches the transmission type sensor 24 (see FIG. 5) installation portion, and the coin A shown in FIG.
When the binarized signal shown in is raised from "0" to "1",
The CPU 30 outputs an image capturing command to the CCD camera 22, and the CCD camera 22 captures an image of the entire surface of the coin A on the conveyor belt 18 under illuminated conditions.

In the first step S1, the CPU 30 causes the CCD
Image data from the camera 22 (coin pattern image data)
After analog-to-digital conversion is performed by the A / D converter 25, image input by reading and inputting through the image memory 26 is executed. Next, in a second step S2, the CPU 30 executes edge emphasis processing for the purpose of improving the contrast of the coin pattern.

Next, in a third step S3, the CPU 30 executes noise removal processing to clear the coin image, and in a fourth step S4, the CPU 30 performs circle detection for determining the outer diameter of the coin A, Further next fifth step S5
Then, the CPU 30 executes the process of extracting the features of the coin pattern based on a certain rule stored in the RAM 29, and in the next sixth step S6, the CPU 30 stores the correct coin feature data (front and back) stored in the RAM 29 in advance. The denomination determination is performed by collating with the data of both sides). In addition,
The denomination determination result is output to the output device 31 shown in FIG.

As described above, the medium conveying means (see the conveying belt 18) carries the medium (see the coin A) on its upper surface and conveys the medium, and the medium detecting means (see the transmissive sensor 24) conveys the medium (the coin). Of the medium detection unit (see the transmission type sensor 24) is narrowed down by the detection area regulation unit (see the base 23). To do.

For this reason, the ratio of the thickness of the coin A to the detection area (see the light receiving area 24a) at the time of coin detection by the transmissive sensor 24 is relatively increased, so that the coin detection signal from the transmissive sensor 24 is transmitted. The change level becomes large, and there is an effect that the coin A reaching a predetermined position can be accurately detected.

Further, when the pattern of the coin A is picked up by the CCD camera 22, it is possible to obtain a timing signal for image acquisition without deviation and prevent the coin image from protruding from the screen. There is an effect that can be done.

8 and 9 show another embodiment of the light receiving area forming structure in the sensor mounting portion, that is, the detection area regulating means. The configuration of FIG. 8 has a slit-shaped light receiving area forming member 40.
Is provided to form a slit-shaped light receiving area 41 that is elongated in the vertical direction and is relatively narrow. With this configuration, the time during which the tip of the coin A moves in the traveling direction and is present in the light receiving range of the transmissive sensor 24 (see the previous figure) is significantly shortened, so that the S / N ratio is relatively improved, Since the edge position variation of the binarized signal is small, the position of the coin A can be accurately detected, the reference timing for image acquisition is made accurate, and the coin image is reliably displayed on the screen. There is an effect that it can be accommodated, and in particular, improvement of denomination identification performance can be achieved.

In the structure shown in FIG. 9, a semiconductor laser or a point light source LED having a small light emitting portion is used as a light projector used as a trigger sensor, and a lens (not shown) shapes the beam into parallel light, so that the beam diameter is relatively small. The light receiving area 42 is formed. According to this structure, the light receiving difference level between when the light is transmitted and when the light is blocked is relatively large, and the time during which the tip of the coin A is present in the light receiving area 42 of the sensor while being advanced in the traveling direction is significantly reduced. Therefore, the S / N ratio is relatively improved, and the edge position variation of the binarized signal is small.

As a result, the position of the coin A can be accurately detected, the reference timing for image acquisition can be made accurate, and the coin image can be surely accommodated on the imaged screen. There is an effect that an improvement in performance can be achieved.

In the correspondence between the configuration of the present invention and the above-described embodiment, the medium carrying device of the present invention corresponds to the coin processing device 11 provided with the same device of the embodiment, and hereinafter the medium is the coin A. Corresponding to, the medium conveying means is the conveying belt 18
The medium detection means corresponds to the sensor 24, and the detection area regulation means is the base 23 (see FIG. 6), the slit-shaped light receiving area forming member 40 (see FIG. 8), and the semiconductor laser or the point light source on the projector side. Although it corresponds to an LED lens (neither is shown), the present invention is not limited to the configuration of the above-described embodiment.

[Brief description of the drawings]

FIG. 1 is a side view of a coin processing device including a medium carrying device of the present invention.

FIG. 2 is an enlarged view of only a part of FIG.

FIG. 3 is a view taken along the line CC of FIG.

FIG. 4 is a plan view of FIG.

FIG. 5 is a block diagram of a control circuit of the coin processing device.

FIG. 6 is an explanatory diagram showing a relationship between a light receiving area and a binarized signal.

FIG. 7 is a flowchart showing denomination determination processing.

FIG. 8 is an explanatory diagram showing a relationship between a light receiving area and a binarized signal.

FIG. 9 is an explanatory diagram showing a relationship between a light receiving area and a binarized signal.

FIG. 10 is a plan view showing a conventional medium carrying device.

FIG. 11 is an explanatory diagram showing a spread state of a light beam.

FIG. 12 is an explanatory diagram showing a relationship between a conventional light receiving area and a binarized signal.

[Explanation of symbols]

 18 ... Conveyor belt 23 ... Base 24 ... Sensor 40 ... Slit-shaped light receiving area forming member

Claims (1)

[Claims] 1. A medium transporting device for transporting a medium, comprising a medium transporting means for transporting the medium on an upper surface, a medium detecting means for detecting that the medium has reached a predetermined position, and the medium detecting means. A medium carrying device comprising a detection area regulation means for regulating the detection area of the means in a narrow direction.