JPH02304690A - Method for counting stacked platelike substances - Google Patents

Abstract

PURPOSE:To accurately count up the number of stacked platelike substances by comparing the brightness level of the stacked platelike substances with a prescribed threshold and counting the number of repeats of comparing data to find out the number of stacked platelike substances. CONSTITUTION:The brightness level of an image for the end face of an object 1 to be counted is scanned in the stacked direction through a CCD linear image sensor 4 and an obtained output signal 4a is inputted to an A/D converter 7 through an amplifier 6 to obtain digital output data 7a. The data 7a are written in an image data memory 9 from a memory writing circuit 8 to obtain a value corresponding to a change in the cross section of the object 1. The data of the memory 9 are computed by an arithmetic circuit 10, and if a periodical change is extracted, the object 1 can be counted. As to the operation, a threshold e.g. is prepared to compare the size of the data 7a with the threshold. When threshold <=data 7a is set up to '1' and threshold>data 7a is set up as '0', the number of stacked plates of the object 1 can be decided by counting up the number of changes from '0' to '1'.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for automatically counting the number of stacked plate-like objects, such as cards (prepaid cards, credit cards, etc.), printed circuit boards, etc. Note that in the following figures, the same reference numerals indicate the same or corresponding parts. Also, logic “1” and “0” are simply “l”. It shall be written as "0'.

[Conventional technology]

A method for automatically measuring the number of stacked plates is to measure the total length of the plates in the stacking direction or the total weight of the plates as a substitute value for the number of plates, and calculate the number of plates per plate. A method of measuring the total number of sheets from the thickness or weight is known.

[Problem to be solved by the invention]

However, in the method of counting the number of plate-like objects as described above,
If the variation in thickness or weight per sheet used as a substitute value is relatively large, there is a drawback that the total number of sheets of the plate-like object cannot be accurately measured. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem by providing a method for counting stacked plate-like objects by scanning an image of the end face of the stacked plate-like objects and determining the number of stacked plate-like objects.

[Means to solve the problem]

In order to solve the above-mentioned problems, the method of the present invention adjusts the brightness level of the image about the end face of the stacked plate-like object (such as the metering object 1) by adjusting the brightness level of the image (CCO linear image sensor 4
etc.) in the stacking direction, and the brightness level (to/D converter output data 78, etc.) obtained with this scanning is set to a predetermined threshold value (via the arithmetic circuit 10, etc.). and the number of repetitions of this comparison data (
It is assumed that the number of stacked plate-shaped objects is determined by counting (via the arithmetic circuit 10, etc.) to obtain the stacked number of the plate-like objects.

[For use]

An image sensor collects image data in the stacking direction of plate-like objects,
The image data is loaded into the memory using an A/D conversion circuit and a memory writing circuit, this data is processed by an arithmetic circuit, and the total number of plates is counted by counting the number of times the data is repeated in the stacking direction. be.

【Example】

The present invention will be explained in detail below based on FIGS. 1 and 2. FIG. 1 is a block diagram showing a configuration as an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation of FIG. 1. In FIG. 1, reference numeral 1 denotes an object to be counted, which is a stack of plate-like objects such as prepaid cards, and this object 1 includes a rod lens array 3 and a CCD linear image sensor 4.
and are placed at a predetermined distance from each other. Here, the rod lens array 3 includes a plurality of cylindrical (rod) shaped lenses (rod lenses) each having a diameter of approximately 1 to 1.5 φ, and are arranged so that the axes of the cylinders (also referred to as optical axes) are parallel to each other. They are arranged in a straight line in almost close contact with each other, and in this example, the direction of this arrangement (array) and the stacking direction of the objects 1 to be counted are arranged so that they are aligned. The CCD linear image sensor 4 also has a plurality of CCD sensor elements arranged in a straight line to convert the input light from its own aperture into an electrical signal corresponding to its brightness, and the direction of this arrangement is also variable. , is configured to be aligned with the arrangement direction of the rod lenses in the rod lens array 3. 2 (2-1, 2-2) are lamps that illuminate the objects to be counted, and the type and brightness of the light source are determined by the sensitivity 1 spectral characteristics of the image sensor 4 and the optical characteristics of the rod lens array 3. In addition, the lamp 2-1.2-2 is the target object 1.
It can be installed at the optimal position depending on the material (optical properties), thickness, etc. In this way, each rod lens in the rod lens array 3 transfers the image of the object l input from the front of its own optical axis to the corresponding CCD sensor element in the linear image sensor 4 located behind its own optical axis. Tie the parts 1:l. Therefore, by reading out the output signals of the CCD sensor elements of the linear image sensor 4 via the CCD drive circuit 5 in the order of the arrangement of the sensor elements, image data in the stacking direction of the objects to be counted 1 can be obtained. Here, the CCD drive circuit 5 generates shift pulses and transfer pulses necessary for the operation of the CCD linear image sensor 4. This circuit generates a reset pulse, etc., and the width, timing, etc. of this pulse are determined by the characteristics of the image sensor 4, etc. In the above configuration, in order to focus a clear image of the object to be counted 1 on the aperture of the linear image sensor 4, the rod lens array 3 is arranged such that the center of the rod lens in the optical axis direction is located between the linear image sensor 4 and the object 1. It is installed at a position of 172 with a distance of . Also, the resolution of the CCD linear image sensor 4 is
It is basically determined by the size of one CCD sensor element as a pixel, and here, a 7 μm one was used. Furthermore, since the image to be captured may be one row of images in the stacking direction of the objects 1, a linear image sensor in which pixels are arranged in series in one row is used, and the number of pixels is determined by the stacked dimensions of the objects. For example, if the pixel size is 7 μm and the number of pixels is 5000, then 7 am x 5000 = 35 mm, which makes it possible to count objects 1 whose total stacked length is 35 mm or less (in reality, it is necessary to provide a little more margin). Next, 6 is an amplifier, which is a circuit for amplifying minute electrical signals outputted from the linear image sensor 4 in accordance with image data. It is also assumed that the amplifier 6 has a function of removing signals unrelated to one image data accompanying the output signal of the image sensor 4. Reference numeral 7 denotes an A/D converter, which is a circuit that converts an analog signal corresponding to the image data outputted from the amplifier 6 into a digital signal, and here the output is 8 bits. Therefore, there are eight outputs of the A/D converter, and digital values are output in the range of 0 to 255 depending on the magnitude of the human input signal. Reference numeral 8 denotes a memory write circuit which sequentially writes output data from the A/D converter 7 into predetermined areas of the image data memory i. 9 is the image data memory, which is at least 50
A capacity of 00 pixels x 8 bits, that is, 5000 bytes or more is required. 1O is an arithmetic circuit which reads data from the image data memory 9 and performs arithmetic processing necessary for counting. Next, details of the counting operation shown in FIG. 1 will be explained using FIG. 2. FIG. 2(1) is a diagram schematically showing a cross section (outline) of the object 1 to be counted in the stacking direction. That is, this cross section shows a cross section when the object 1 is cut along a plane perpendicular to the plate surface of the plate-shaped object 1 and parallel to the stacking direction. When the image data obtained when the object 1 having such a cross section is imaged from the bottom to the top of the paper in FIG. 2 is input into the CCD linear image sensor 4 as described above, the output signal from the image sensor 4 is 2a can obtain a signal whose Vdata changes as shown in FIG. 2(2) in accordance with the change in the cross section shown in FIG. 2(1). The magnitude of Vdata can be obtained up to the maximum lv as a characteristic of the image sensor 4, but since this value is the saturation voltage, in reality, the light intensity of the two lamps and the image sensor are adjusted so that it does not reach the saturation voltage even in the worst case. Optimize the image capture time etc. in step 4. In addition, the image sensor output signal 4a
In addition to the true image data output (Vdata), the image sensor output signal 4a as shown by R in FIG.
The pulse for extraction is superimposed as noise and output. Then, this image sensor output signal 4a is input to an amplifier 6, where the image data is inverted and amplified, and unnecessary noise R is removed to obtain an amplifier output signal 6a shown in FIG. 2(3). Furthermore, the amplifier output signal 6a is input to an A/D converter 7, and a digital output signal a as shown in FIG. 2 (4) is obtained as its output. Then, this A/D converter output data 7a is written into the image data memory 9 by the memory write circuit 8 as described above. This write circuit 8 is a DMA (Di
Data is written into the image data memory 9 at high speed using a method called rect Memory Access. In this way, numerical values corresponding to changes in the cross section of the object 1 are written in the image data memory 9. Therefore, if the data in the image data memory 9 is subjected to some calculation by the calculation circuit 10 and periodic changes are extracted, it becomes possible to easily count the objects l. For this calculation, for example, a threshold value of 100 is set, and a comparison is made between this darkness value and the data stored in the image data memory 9 (therefore, in this example, the A/D converter output data 7a), and (darkness value) ≦ (data In case of 7a) “1
”, (dark value)> (data 7a), if it is “O”, then
The calculation result is as shown in FIG. 2 (5). From this result “
From “0” to “1” (or vice versa from “1’ to “0”)
By counting the number of changes, the number of stacked objects 1 can be determined. It is more economical to configure the arithmetic circuit 10 with a microcomputer, but if high speed is required, it is necessary to configure it with dedicated hardware. In addition, as for the other method of size comparison using the above-mentioned dark value, A/
The D conversion circuit 7 is replaced with a comparator, and this comparator compares the analog comparison reference value as a dark value with the amplifier output signal 6a, and "l" and "0" corresponding to large and small as a result of this comparison. A method such as writing the data of `` into the image data memory 9 may also be considered.

【Effect of the invention】

According to the present invention, image data in the stacking direction of objects to be counted is captured into a CCD linear image sensor, changes in the image data are converted into electrical signals, periodic changes in the electrical signals are extracted and counted, and the number of stacked objects is counted. Since the number of stacked sheets can be accurately counted even if there are variations in the thickness of the objects.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operation of FIG. 1. 1: Counting object, 2 (2-1, 2-2): Lamp,
3: Rod lens array, 4: CCD linear image sensor, 5: CCD drive circuit, 6: Amplifier, 7: 8/D
Converter, 8: Memory writing circuit, 9: Image data memory,
10: Arithmetic circuit.

Claims (1)

[Claims] 1) Scan the brightness level of the image of the end face of the stacked plate-like objects in the stacking direction, compare the brightness level obtained with this scanning with a predetermined threshold, and A method for counting stacked plate-like objects, characterized in that the number of stacked plate-like objects is determined by counting the number of times comparison data is repeated.