JPS60118547A - Detection system of reaching of paper between feeding rollers - Google Patents

Abstract

PURPOSE:To perform paper detection accurately by applying alternating current of the fixed period to conductive rollers and removing noise component from th produced signal through a band-pass filter. CONSTITUTION:Conductive portions (5a, 5b) and 6a are formed opposite to each other in a pair of feeding rolles 5 and 6 which put papers between and feed them. A sine wave signal of the fixed period is supplied to these conductive portions (5a, 5b) and 6a from an oscillator 26, this signal is converted to a current voltage by operation amplidynes 19 and 27 of an original sensor, and thereafter it is inputted into a band-pass filter 20. An electrical change due to the fact that whether or not there is an original between the pair of rollers 5 and 6 is grasped accurately by demodulating and detecting this input signal through this filter 20, thereby detection of the original is performed with certainty.

Description

[Detailed description of the invention] (Technical part!i!]') The present invention relates to a method for detecting paper sheets between feed rollers in a document reading device or a copying machine,
There are several methods for detecting electrical changes between feed rollers.

(Hirata technology) Conventionally, the mechanisms for detecting paper sheets (hereinafter referred to simply as paper2) between a pair of feed rollers include a microswitch method and a photo sensor method, as well as a method in which the feed roller is made of a conductive material. A method is also known in which the arrival (presence) of paper is detected by detecting an electrical change when an insulating paper is passed through the paper during this time.

However, the problem with this type of conventional system is that the electrical contact between the conductive rollers is poor, so malfunctions easily occur.

(Purpose) The present invention has been made in view of the drawbacks of the conventional method, and it is an object of the present invention to provide a detection method that accurately detects electrical changes depending on the presence or absence of paper and performs paper detection correctly. It is something.

(composition) The configuration of the present invention will be explained below based on the illustrated embodiments.

Note that the embodiment shows a document reading device.

FIG. 2 shows the document transport section of the yA document reading device.

The original O is inserted in the direction of the arrow and reaches the Haratachibana sensor 1. The document sensor 1 is composed of a conductive brush 2 and a metal electrode 3 in order to minimize the force applied to the leading edge of the document.

The conductive brush 2 is made of metal fiber with a diameter of 1" and is generally known as a static elimination brush.

An alternating current with a constant cycle is constantly flowing between the ijb'lh brush 2 and the electrode 3, and the current is cut off when the original passes through the brush 2 and the electrode 3. Changes in the current are detected by a detection circuit for the i-document sensor 1 shown in FIG. 3, which will be described later, to detect passage of the document. This document sensor l is provided for the purpose of detecting that the document has been submitted manually.

Suzutachibana sensor 1IJ'' - When the document is detected, the stepping motor 4 shown in Fig. 1 is driven, and the 10th and 2nd
0-Ra 6 starts rotating. Manually 10th-Ra 5
．． The document inserted up to the entrance of the 20th roller 60 is bitten between the rollers. As shown in the figure, the 10th roller 5 has two conductive materials 5a and 5bk such as rubber, and the openings thereof are electrically insulated. 20th
- The roller 6 has a conductive material 6a such as a metal having a certain width arranged at its center, and is electrically insulated from other parts. The arrangement relationship of the conductive materials of the 10th layer 5 and W, and the 20th layer 6 is as shown in FIG.

A conductive brush 7.8 is placed in contact with the tenth roller 6 and is electrically connected to the outside.

Further, the 10th roller 5 and the 20th roller 6 are pressed against each other by a spring, and electrical connection is maintained between the conductive abrasive materials.

In order to improve this electrical connection, FIG. 4 shows a 10th roller with 5 separation rollers and the diameter of the portion of the conductive material made somewhat thicker to improve the electrical contact ability.

Also, the conductive brush 7.8 and the 10th roller 5. An alternating current is passed through the conductive material portion of the 20th roller 6. When a document is bitten between these rollers, the current between them is cut off. Therefore, each lead '1. Materials 5a, 5b, 6
A and the conductive brush 7.8 constitute the original 1°4 sensor 9. In addition, in Fig. 1, 10.12 is a pulley, 1
1 is the timing belt (JJJ4. The change in the current of the sensor 9 is detected by the detection circuit section of the sensor 9 in Figure 3, and the output of 1.16t J+!) In addition, in Figure 2, j, top soil) JJ (i, top soil)
1 guide, 14 indicates the original reading position, 15 indicates the glass, and 16 indicates the fluorescent light.

Next, the detection circuit shown in Figure 3 will be explained.

The detection circuit section 17 for the original 41-race/two-1 is connected to the electrode 3. 8, pm bloody brush 2. Obeah 7p 19° band pass filter 20. Diode 21. :
ff energizer 22, and finally an output l is output.

In addition, the original 4iXh sensor September detection circuit section 23 is similarly connected to the core 20-lar 6. Switches 24, 25. 10th-ra 5.5+frictional brush 7.82 oscillator 26. Opean/”
27. Bandpass filter 28. Diode 29. It consists of a comparator 30 and finally outputs an output 2.

The switch in Figure 3 is provided for convenience to show the relationship between the conductive flange 2 and the 'electrode 3 in Figure 2; when the switch is closed, there is no yA camphor, and when the switch is open, there is no yA camphor. When , the original is ringing.

Switches 24 and 25 are used to conveniently show the electrical connection between the 10th and 20th rollers 5 and 6, and when the switches 24 and 25 are closed, it is llA; no B4, and the switch 24.25 is closed. When 25 is open, there is a document.

FIG. 5 is a timing chart of the detection circuit section of FIG. 3. The output of the oscillator 26 is a sine wave signal with a constant period. The signal s1 passes through the document sensor 1, becomes a signal S, and is input to the operational amplifier 19.

The operational amplifier 19 converts current to voltage (the Q signal is input to a bandpass filter 20 that passes only the frequency of the signal SI from the oscillator 26.Then, the output is half-wave rectified by a diode 21 and output as a signal s3 to the comparator. 22 to perform binarization at a constant threshold.

The above signal SI is also supplied to the document sensor 9, and a signal S
, and undergoes the same processing as in the detection circuit section 17 for the original sensor l to become the signal S7. The Ryogo position is detected by the movement f1 as described above.

In FIGS. 1 and 5, '1'1 indicates the timing at which the document sensor 1 outputs the leading edge of the document, and 1it2 indicates the timing at which the document sensor 9 detects the leading edge of the document, respectively.

Another example and application as shown in FIG. 6 can be considered in 1.

That is, in order to remove only the necessary parts 31a, 31b of Hara 44% 31, one coat of the special substance 32.33 was applied to the ends of the necessary parts 31a, 3ib (J).
When inserted into the 10th roller 5 and the 20th roller 6, a current may or may not flow through the conductive material 32, 33 of the first roller 5 to the binding 11i: flange 7.8.

By detecting this difference r, it is possible to judge whether there is a need to read or not, and it is possible to read only the amount b6.

The above embodiment was related to a document reading device, but A
It goes without saying that 1 can also be used for the paper conveyance path 1f' (l) of the tracing copying machine mentioned above.

(Effects) The present invention is as described above.According to the present invention, a constant periodic Ik output is applied to the conductive roller, and the noise component is removed from the signal extracted from it through a band pass filter. i: By doing so, paper can be detected accurately.

[Brief explanation of drawings]

Fig. 1 is an external perspective view of the conductive roller portion, Fig. 2 is a simplified mechanism diagram for document reading and preparation, Fig. 3 is a paper sheet detection circuit diagram according to an embodiment of the invention, and Fig. 4 ( FIG. 5 is an external perspective view showing another configuration of the conductive roller, FIG. 5 is a circuit diagram similar to FIG. .6...Feed roller pair, 5a, 513.6
a... Conductive part, 26... Oscillator, 28
...Band pass filter. Figure l Figure 3 Figure 4 Figure 5 Figure 5 83-11111 Figure 6

Claims (1)

[Claims] Paper cold treatment: 4" + ij iib f is formed facing each other in the pair of feed rollers for sandwiching and selling, and the conduction depending on the presence or absence of paper sheets. In the device that detects all arrivals of paper sheets, the signal is supplied to the terminal section which breaks the fixed period, and the signal is detected by a band-pass filter. By this, paper light is detected between the feed rollers and the paper is detected by A detection method.