JPS63295906A - Measuring system for length of paper sheet - Google Patents

Abstract

PURPOSE:To enable the accurate measurement of length of a bank note even when it is in a bad detecting condition, by setting an individual slice level for each sensor bit constituting a line sensor. CONSTITUTION:A bank note 3 advances along a conveyance route, and a light source 1 having light-emitting elements connected in a line and a line sensor 2 having a number of sensor bits formed by arranging photosensitive elements in a line are provided in two pairs on the opposite sides of the route. When a start signal for a processing of receipt or payment of the bank note 3 is inputted to a control unit 5, a sampling mode turns operative. Then the light source 1 emits a light, a voltage level corresponding to the quantity of the light received by each sensor bit of the sensor 2 is inputted to the unit 5 through an amplifier 8 and an A/D converter 12, and thereby an individual slice level is set. When a measuring mode becomes operative, subsequently, a measured output level of the sensor 2 is inputted from the unit 5 to a comparator 10 through the converter 12 and subjected to an operation of comparison with the slice level. In this way, a position of passage of the bank note 3 is detected and the length thereof can be measured in the direction perpendicular to the direction of conveyance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to a paper sheet length measuring method for measuring the dimensions of paper sheets such as banknotes.

[Conventional technology 1] For example, in banknote depositing devices, dispensing devices, etc., the length of banknotes is measured in order to check the denomination of the banknotes to be processed, the presence or absence of damage, the conveyance state, etc. . The mechanism for measuring the length of banknotes is a line sensor consisting of a light source such as an LED, and a light receiving element that converts the amount of light received from the light source into an electrical signal. A banknote conveying path is formed between the light source and the line sensor, the line sensor is connected to a signal processing means, and the signal processing means processes the output signal from the line sensor. Conventionally, devices have been used in which the length of banknotes conveyed through the conveyance path is measured.

Since the output level of the sensor bit made up of each light-receiving element constituting the line sensor described above differs depending on whether or not a banknote has passed the position of the sensor bit, the signal processing means uses A level between the output level of the sensor bit during passing and the output level during passing is set as a slice level, and the measured output signal of each sensor bit in the line sensor input to the signal processing means is set to this slice level. The length of the banknote is measured based on this comparison signal.

[Problem to be Solved by the Invention 1] By the way, even when a line sensor is irradiated with a constant amount of light from a light source, each sensor bit changes depending on the distance between it and the light source, temperature, etc. There may be variations in the output level.

For this reason, the aforementioned slice level must be set to a value lower than the lowest output level, taking into account variations in the output level of each sensor bit. However, the paper sheet to be measured is thin, such as banknotes, and some of it has watermarks, or it has been used for a long time and has oil stains, etc. When something is present, the amount of transmitted light in that area increases,
There is a drawback that the output level of the sensor bit becomes higher than the slice level, making it impossible to perform accurate length measurement.

The present invention was made in consideration of the ridges, and an object of the present invention is to provide a paper sheet length measurement method that can measure the length of paper sheets with poor detection conditions, such as banknotes, with extreme accuracy. That is.

[Means for Solving the Problems 1] In order to achieve the above-mentioned object, the present invention provides a sensor bit consisting of a light source and a light receiving element that converts the amount of light received from the light source into an electrical signal. a line sensor formed by consecutively arranging the light source and the line sensor, a length measuring means formed by forming a conveying path for paper sheets between the light source and the line sensor, and measuring signals at each of the sensor bits at a slice level. and a signal processing means for comparing the length of the paper sheet conveyed on the conveyance path, the output signal level from each of the sensor bits is sampled before the sheet conveyance, and The feature is that the slice level is set for each sensor bit.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, FIG. 1 shows an apparatus configuration for implementing the method of the present invention. In this embodiment, the apparatus will be described as being attached to a banknote processing apparatus for processing banknote deposits, withdrawals, etc., and measuring the length of banknotes processed by the banknote processing apparatus.

In the figure, 1 is a light source in which light emitting elements such as LEDs are arranged in a line, and 2 is a light receiving element in a line shape that receives light from the light source 1 and outputs a voltage signal according to the amount of received light. Each line sensor has a large number of sensor bits formed by arranging the sensor bits, and between the light source 1 and the line sensor 2, a sensor bit is conveyed by a conveying means (not shown) such as a belt, a roller, etc. (A feeding path 4 is formed, and a length measuring means for measuring the length of the banknote 3 is configured. 2 are not provided over the entire length of the conveyance path 4, but are provided in pairs on both sides, thereby controlling the positions of both sides in the direction orthogonal to the conveyance direction of the banknotes 3 conveyed through the conveyance path 4. is detected, and the length of the banknote 3 can be measured based on this detection, thereby simplifying the length measuring mechanism and speeding up the processing.

The control device 5 serves as a signal processing means for processing the output signal from the line sensor 2 constituting the aforementioned length measuring means.
is provided between the control device 5 and the line sensor 2 in order to read the signal of each sensor bit of the line sensor 2 from the control device 5. A scan address signal cable 8 for inputting is connected. On the other hand, the output signals of the line sensor 2 are inputted to amplifiers 8 and 8 via an output signal transmission cable 7, respectively.

A mode switch 9.9 is connected to each of these amplifiers 8, and each mode switch 3 allows the amplifier 8 to
The output signal of each bit in the line sensor 2 amplified by
It is possible to switch between the path via the D converters U and tt. Therefore, when the path via the D/A and A/D converter 11 is selected, the sampling mode is set, and the output signal of each bit of the line sensor 2 is converted into a digital signal via the D/A and A/D converter 11. After being converted into a signal, the control device 5 can set a predetermined slice level for the output level of each bit described above. On the other hand, when the path via the comparator 10 is selected, the measurement mode is entered, and the output signal of the bit input to the comparator 10 is transmitted from the control device 5 to the D/A and A/D converter via the data bus 12. The signal from the comparator IO is inputted to the control device 5 and stored in the memory in the control device 5.

The apparatus for carrying out the method of the present invention is constructed as described above.Next, a method for measuring the length of banknotes 3 using this apparatus will be explained with reference to FIGS. 2 to 4. .

When performing processing such as deposits and withdrawals using the paper Wi3, the processing is started by operating an operation panel (not shown). Therefore, the signal related to the start of this process is the control trace @5
Based on the signal from the control device 5,
First, each mode converter 9 switches to sampling mode, and the light source 1 emits light. Therefore, the scan address signal from the control trace N5 is input to the line sensor 2 every moment via the scan 2 address signal cable B, and a voltage level corresponding to the amount of light received by each sensor bit in the line sensor 2 is output. The signal is passed through amplifier 8 to D
/A, digitized by the A/D converter 11 and input to the control device 5.

The processing in this sampling mode is for individually setting the slice level for each sensor bit in the line sensor 2, and for this purpose sampling of the output level of all sensor bits is performed. Then, the control device 5 sets a slice level for each sensor bit based on the output signal of each sensor bit in the state before the bill 3 passes, which is obtained in this way. It must be set so that the level of transmitted light is higher than that in areas with oil stains, etc.
For example, the output level may be set to about 80% of the output level for each sensor bit when the paper ff13 does not pass. In this way, as shown in FIG. 2, the slice level ■ is individually set for the output level ■ of each sensor bit blNbn in the line sensor 2.

When the setting of the slice level for each sensor bit of the line sensor 2 is completed as described above, the mode switch 8 is switched to the measurement mode. And conveyance path 4
When the banknote 3 being conveyed reaches the position of this length measuring means, a scan address signal is input from the control device 5 to the line sensor 2 via the scan address signal cable 6, and the signal of each sensor bit is read out. The output signal from each sensor bit is inputted to the comparator IO via the amplifier 8, and the measured output level is output from the control device 5 to the D/A, as shown in FIG. 3(a). A/
By comparing and calculating the slice level of the sensor bit inputted to the comparator 10 via the D converter 11, the passing position of one banknote 3 can be detected as shown in FIG. 3(b). become able to. In this way, by detecting the positions of both ends of the banknote 3 passing through the line sensors 2 on both sides, the length dimension of the banknote 3 in the direction orthogonal to the conveying direction can be measured. As a result, it is possible to perform a differential inspection on the type of banknote 3, presence or absence of damage, conveyance conditions, etc.

A flowchart of the aforementioned measurement procedure is shown in FIG.

Thus, the line sensor 2 and the light source 1 that irradiates light to the line sensor 2 are both provided in a line shape,
For this reason, the output level of each sensor bit making up the line sensor 2 may not be uniform due to various reasons.

However, as mentioned above, since the slice level is set individually for each sensor bit, the output level based on the amount of transmitted light of the banknote 3 at each sensor bit is different even if the banknote 3 has a watermark. Even if the amount of transmitted light at the relevant site increases due to oil stains, the amount of transmitted light will not exceed the individually set slice level. Therefore, the accuracy of measuring the length of banknotes 3 is significantly improved.

In addition, in the above-mentioned embodiment, the length of the banknotes is measured, but the length of paper sheets to be subjected to the length measurement process is not limited to the above-mentioned ones, but the length of various securities etc. can also be measured. Also, although the pair of line sensors are disposed at both ends of the conveyed sheet, the line sensors may be configured to detect the entire length of the conveyed sheet. moreover,
When measuring the length of multiple paper sheets in one operation, the slice level setting described above can be set at the start of the operation, or it can be set only once when the device is powered on. The level may be set, and the slice level may be changed every time the length of one sheet of paper is measured.
Furthermore, when performing length measurement processing on banknotes, since the length is specified to a certain extent, it may be preferential to scan a specific part with the line sensor. .

[Effects of the Invention] As detailed above, according to the method of the present invention, the slice level is individually set for each sensor bit making up the line sensor. It becomes possible to measure the length of paper sheets such as banknotes with parts extremely accurately.

[Brief explanation of the drawing]

FIG. 1 shows an apparatus structure for implementing the method of the present invention. Fig. 2 is an explanatory diagram of signal processing in sample mode, Fig. 3 (a) and (b) is an explanatory diagram of signal processing in measurement mode, and Fig. 4 is an explanatory diagram of signal processing in measurement mode. It is a flowchart figure for implementation. 1: Light source, 2: Line sensor, 3: Banknote, 4:
Conveyance path, 5: Control device, 9: Mode switch, 10: Comparator.

Claims (1)

[Claims] comprising a light source and a line sensor formed by consecutively arranging sensor bits in a line, each consisting of a light receiving element that converts the amount of light received from the light source into an electrical signal;
It has a length measuring means formed by forming a conveying path for paper sheets between the light source and the line sensor, and a signal processing means for comparing the measurement signal at each sensor bit with a slice level, In the method for measuring the length of paper sheets, the output signal level from each of the sensor bits is sampled before the paper sheet is conveyed, and a slice level is set for each of these sensor bits. A length measurement method for paper sheets.