JPH0246097B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an object inspection system, and particularly to a system for determining the state of an object to be inspected such as a paper sheet using a one-dimensional array sensor such as a photodiode array or an image sensor as a detector. This invention relates to an inspection system that performs.

[Background of the invention]

When automatically determining the dimensions of a paper sheet such as a banknote, whether it is damaged or folded, a sensor with a one-dimensional field of view, such as an image sensor or a photodiode array, is used.

FIG. 1 shows an example of the image input section of such a system. In FIG. Now, when the sensor field of view is at the position shown in the figure with respect to the paper sheet 1 being conveyed in the Y direction, the sensor 3 detects the area A (A ₁ , A ₂ , A ₃ ,
In area A ₄ ), there is no object, and in area B (B ₁ , B ₂ , B ₃ ), there is an object detected.

The image sensor 3 is a collection of N independent sensors with a width P, and in conventional paper sheet inspection,
The information of each pixel of the image sensor is scanned in the X direction from the left end to the right end, read out sequentially, and then binarized and converted into bit data of "1" or "0", resulting in a total of 1 After creating one data word, pattern judgment processing was performed. For this reason, if you increase the number of picture elements in the sensor and try to judge the state of the paper sheet with high resolution, the number of bits of data subject to pattern judgment will increase, compared to when dealing with normal coded data. As a result, the number of program processing steps required for pattern determination increases, resulting in a problem that data processing becomes complicated.

[Purpose of the invention]

An object of the present invention is to facilitate the processing of sensor information by a data processor in a system for determining the state of an object to be inspected using the above-described sensor having a one-dimensional field of view.

[Summary of the invention]

In order to achieve the above object, the object inspection system of the present invention includes a one-dimensional sensor disposed across the conveyance path of the object to be inspected, a scanning means for sequentially reading out pixel information of the sensor, and a reading device. means for converting the emitted pixel information into binary pulses; a first counter for counting the pulses and storing a count value indicating the position of one end of the object to be inspected; a second counter that stores a count value indicating the total size of the presence range or absence range of the detected object; a third counter that counts the pulses and stores a count value that indicates the other end position of the object to be inspected; It is characterized by comprising a data processor that takes in the values of each of the counters each time one cycle of sensor scanning is performed and performs a predetermined judgment operation from each counted value.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of a sensor output processing circuit according to the present invention, in which 3 is an image sensor having a one-dimensional field of view 3', and 4 is a block diagram that compares the output of the image sensor 3 with a predetermined threshold value and sequentially compares the output of the image sensor 3 with a predetermined threshold value. 1”,
Binarization circuit for converting to “0” bit, 21 to 24
is a counter, 31 to 34 are latch circuits that latch the count values of each of the above counters with a timing pulse T _E , and 40 is a count value of each of the above latch circuits.
A multiplexer is shown that selects D ₁ to _{D 4} in accordance with an address signal AD from a data processor (not shown) and inputs data D to the data processor.

The image sensor 3 is composed of _N sensors as explained in FIG. The signal is output and converted into a binary signal by the binarization circuit 4. The timing pulse generating circuit 50 outputs a pulse T _S prior to the sensor scanning, thereby clearing the counters 21 to 24, respectively. Also, the latch timing pulse mentioned above
T _E is the pulse generation circuit 5 after the scanning of the sensor 3 is completed.
Generated from 0.

The operations of the counters 21 to 24 in FIG. 2 will be explained below with reference to FIG. 3.

Now, assuming that the sensor field of view 3' is facing the three missing parts 2, 2', and 2'' on the sheet of paper 1 as shown in FIG. 3, the information in the image sensor 3 is , the picture elements corresponding to areas A ₁ , A ₂ , A ₃ , A ₄ , and A ₅ are in a state where there is no object, and the areas B ₁ , B ₂ , B ₃ , and B ₄ are in a state where an object is present.

The binarization circuit 4 outputs a pulse to the signal line S ₀ when the read information from the picture element indicates that there is no object, and outputs a pulse to the signal line S ₁ when the read information from the picture element indicates that there is an object.

The first counter 21, as shown in FIG.
The number of pulses on the signal line S ₀ (hereinafter simply referred to as pulse S ₀ ) input through the AND gate 11 is counted. In this case, the AND gate 11 is
It is controlled by the set output of the flip-flop 12, which is set by the start pulse Ts, and
Since the flip-flop 12 is reset by a pulse on the signal line _S1 (hereinafter simply referred to as pulse _S1 ), the number of input pulses to the first counter 21 corresponds to the picture of the first object-free area _A1 . This corresponds to a prime number, and its value _D1 will be stored in the latch circuit 31.

The second counter 22 counts the pulses during one scanning period.
The number of S ₀ is counted, and its final value D ₂ indicates the total length of the object-free area (A ₁ +A ₂ +A ₃ +A ₄ +A ₅ ) including the missing parts 2, 2', and 2''.

The third counter 23 counts the pulse S ₀ , and the start pulse Ts and the pulse S ₁₄ are applied to the clear terminal of this counter via the OR gate 16 . The above pulse _S14 is a flip-flop that is set by pulse _S1 and reset by pulse _S0 .
The reset output of the flop 13 is converted into a pulse by the one-shot circuit 14. Therefore, the value of the third counter is cleared every time the pixel information switches from the state with an object to the state with no object, and the value of the third counter is cleared to a value D ₃ corresponding to the length of the area A ₅ without an object that appears at the end. is passed to the latch circuit 33.

The fourth counter 24 receives the pulse _S14 ,
Output pulse S ₁₅ from one-shot circuit 15 that pulses the set output of flip-flop 13
is input via the OR gate 17. Therefore, this counter 24 counts the number of times the state of the picture element changes, that is, the number of areas A ₁ , B ₁ , A ₂ . . . B ₄ , A ₅ and passes the value D ₄ to the latch circuit 34. become.

As described above, according to the above-mentioned circuit configuration of the present invention, each time the image sensor scans, the first counter 21 stores D ₁ having the length of the area A ₁ indicating the position of the left end of the sheet,
The third counter 23 has a value D ₃ representing the length of the area A ₅ indicating the position of the left end of the paper, the second counter 22 has a value D ₂ indicating the total length of the space without paper, and The fourth counter 24 calculates a value _D5 indicating the number of times the presence or absence of a paper sheet changes.

By taking in these values D ₁ to _{D 4} from the latch circuits 31 to 34, the data processor obtains the known values of the image sensor length L (total number of picture elements) and D ₁ , D ₃ . , the width of the sheet of paper l=L−(D ₁
+D ₃ ), the total length of the missing region l' can be determined by l' = D ₂ - (D ₁ + D ₃ ), and n = (D ₄ -
2) The number n of damaged parts can be determined by /2. Also, by comparing the values of D ₁ and D ₃ ,
It is also possible to know the deviation of the paper sheet in the left-right direction (the position of the paper sheet). Therefore, each time the scan cycle of the image sensor 3 ends, the data processor takes in the numerical data stored in the latch circuit, and
By performing simple calculations, it is possible to calculate the condition determination data of the paper leaf along the It is also possible to perform state determination along the following lines.

In the above embodiment, the area without an object was counted by the second counter, but it is clear that the length of the missing part can be determined even if the area with an object is counted by this counter. Variations other than the examples are possible.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a plurality of counters are used and each time a one-dimensional sensor such as an image sensor scans, these counters are operated to count specific state information of the sensor field of view. This greatly simplifies the arithmetic processing performed by the data processor to determine the state of the object to be inspected, and has the effect of shortening the sensor scanning period and executing the determination processing at high speed.

[Brief explanation of drawings]

1A and 1B are explanatory diagrams of paper sheet image input using a one-dimensional sensor, FIG. 2 is a block diagram of an image data processing circuit showing one embodiment of the present invention, and FIG. 3 is an operation of the circuit of the above embodiment. It is an explanatory diagram. Explanation of symbols, 1... Paper sheet to be inspected, 3
...Image sensor, 4...Binarization circuit, 21...
24...Counter, 31...34...Latch circuit.

Claims (1)

[Claims] 1 placed across the conveyance path of the object to be inspected
a dimensional sensor, a scanning means for sequentially reading the pixel information of the sensor, a means for converting the read pixel information into binary pulses, and a position of one end of the object to be detected by counting the pulses. a first counter that counts the pulses and stores a count that indicates the total dimension of the presence or absence range of the detected object; a third counter that stores a count value indicating the position of the other end of the object to be detected; and a data processor that takes in the values of each of the counters each time one cycle of sensor scanning is performed and performs a predetermined judgment operation from each count value. An object inspection device consisting of: