JPS58111474A - Original detecting system - Google Patents

Abstract

PURPOSE:To detect the insertion of an original with comparatively simple circuit, by providing a stripe pattern colored white and black alternately at the arbitrary same intervals, not in parallel with the scanning direction, for a scanning light irradiating section of an original retaining plate. CONSTITUTION:White and black stripe patterns are provided to the scanning irradiated section of the paper retainer surface of the original retaining plate 1 alternately with the prescribed intervals. An original detection section 6 fetches picture information VD0 at the same time and discriminates the read pattern of insertion/non-insertion of an original, a detected information output DET is transmitted to a control section CONT and detects whether or not the original is inserted through sampling according to a sampling clock SMP.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a tampering document detection method for detecting whether or not a transmitted document, a reading sheet, etc. is inserted into the reading section of a facsimile machine, optical character/figure reading device, etc. It is related to.

Conventional document detection methods of this type include, for example, methods using microswitches, photoelectric switches, and the like.

Those that use microswitches have a simple structure and are relatively economical, but when the original paper is thin (or thin paper originals), it may get caught (so-called jam) when the original is transferred. This tends to occur, and the accuracy of the detection position is also poor.

Those that use photoelectric switches have good detection position accuracy, but alignment between the photodiode and phototransistor is difficult, and detection of thin paper documents is affected by variations in element characteristics and changes in environmental conditions. There is a risk of malfunction due to extraneous light other than the detection light when a document is inserted, and the device is also expensive.

It is an object of the present invention to eliminate the drawbacks of the prior art described above, to eliminate the need for expensive elements, to have a simple configuration, to prevent thin paper documents from being caught, to be unable to detect them, and to improve the document detection ability. The object of the present invention is to provide an economical document detection method.

A feature of the present invention is that the scanning light irradiation section of the document holding plate is not parallel to the main scanning direction of the document, but is alternately illuminated with white light at arbitrary equal intervals.
A stripe pattern that is black is attached, and the difference in the reading pattern of the image information by the reading sensor when the original is not inserted or when the original is inserted is identified, and whether or not the original is inserted is detected. It's in the original detection method.

In short, when no original is inserted, the specific pattern of the above-mentioned stripe pattern read by the reading sensor is an all-white pattern at the starting edge, end edge, etc. when reading a general original, or a random image information pattern in the middle. Since it is clearly different from the original, it is possible to identify it and detect the original.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of the main parts of an embodiment of a facsimile machine to which the document detection method according to the present invention is applied, and FIG.
This is the time chart.

Here, reference numeral 1 refers to a photoelectric conversion section, and a white and black stripe pattern (
In this embodiment, a document holding plate with a color code (painted half-white and half-black), 2#i, a flashlight lamp for irradiating the document,
Similarly, 3 is a reading sensor (for example, a CCD photosensor) that converts optical information from the reflected light of the document irradiation light into an electrical signal, 4 is an amplifier that amplifies the electrical signal to an appropriate level, and 5 is Similarly, converting the black/white binary image information VDO corresponding to the amplified electrical signal mentioned above.
Binarization circuit for output, 6 is a document detection unit, 6Au is its D flip-flop, 6B is for example a Nando game)G
l, G2. G3 is the same gate circuit, 6C is the same branching circuit, and 6D is the same gate switching circuit.

First, as is well known, scan data of a document is read in a photoelectric conversion section, photoelectrically converted and binarized, and the image information VDO is sent to a control section C0NT (not shown) of this apparatus.

The document detection unit 6 simultaneously captures the image information VDO and identifies the non-insertion and insertion reading turns of the document.
The detection information output DET is sent to the control unit C0NT, and its detailed operation will be explained below.

The image information transfer lock CK (for example, the one supplied from the control unit C0NT) is applied to the frequency dividing circuit 6C as well as the image information transmission, and is applied to the frequency dividing circuit 6C, where the frequency is divided by a predetermined frequency division ratio to be described later. SMP, clock terminal C of D flip-flop 6A and gate switching circuit 6
It is applied to D.

First, the operation when no original is inserted will be explained.

In this case, the image information VDO is the striped button on the document holding plate 1 (as mentioned above, it is half white and half black; the first half is the white part W (high level) and the second half is the dotted part B (
low level).

While the "H" (high level) image information VDO of this white portion W is input to the D flip-flop 6A until the end of the sampling clock 8MP pulse C, its positive output Q9 and its inverted output Q are respectively , H'', L'' (low level).

On the other hand, the gate switching circuit 6D uses the sampling clock S
Count the MP pulses a, b, and Ck, and the first pulse C after the stripe pattern moves from the white part W to the dot part B:
At the end point A, the gate switching signal GSW, which has been QH#j, is set to "L".

Further, the D flip-flop 6A is inverted at the end point A of the above-mentioned pulse C, its positive output Q becomes 'L''', and the inverted output point becomes "H", and this state remains during the above-mentioned point part B. Continued.

Therefore, the output of the gate circuit 6B, that is, the detection information output DET, remains at 1H''' from the beginning, and the control unit C0NT determines whether the document is inserted by the detection information output DET and the gate switching signal GSW. It is possible to identify and detect that a turn has occurred.

The division ratio of the image information transfer lock CK by the frequency dividing circuit 6C is determined by the change portion of the stripe pattern from the white portion W to the dot portion B due to the position error of the stripe turn or the fluctuation of the clock CK. It is only necessary to make the pulses of the divided sampling clock SMP more than coincident with each other, and by increasing the division ratio and reducing the number of sampling clocks SMP, the counting function of the gate switching circuit 6D can be simplified. become.

However, when there is no risk as mentioned above, the image information transfer lock C is used as the sampling clock SMP.
It is clear that this does not preclude the use of K as it is.

In the above embodiment, the stripe pattern consists of one white and one black
However, even if there are multiple sets, the detection information output DET will not change in level for each gate switching signal GSW at each switching, so it will be easy to It is possible to identify and detect that a document is not inserted.

Next, the operation when inserting a document will be explained.

For example, if a document is inserted and the scanning area is completely white (in Figure 2, dot area B also becomes white area W, the ``'''' status of each signal is indicated by each broken line. become).

That is, the positive output Q of %D7 lip 70g 6A.

The inverted output Q continues to be "H" without changing.

It remains "L"".

Therefore, at time A when the gate switching signal GSW becomes u L #, the detection information output DET becomes "°L", so the control unit C0NT uses this information to identify that the reading pattern is for the document insertion state.・Can perform detection.

It should be noted that when there are multiple sets of white and black stripes, it is the same as when the document is not inserted as described above, and in short, the detection information output DE is performed every time the gate switching signal GSW becomes "L".
By changing T to 'L'', it becomes possible to identify and detect the inserted state of the document.

This also applies when the image information VDO is not all white but all black or a random pattern.

As described in detail above, according to the present invention, there is no need for special parts for detecting a document, and it is possible to reliably detect whether or not a document is inserted using a relatively simple circuit. , facsimile machine.

Improving the performance and making economics of optical character/figure reading devices, etc.

A remarkable effect can be obtained in improving serviceability.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the main parts of an embodiment of a facsimile machine to which the document detection method according to the present invention is applied, and FIG.
This is the time chart. DESCRIPTION OF SYMBOLS 1... Document holding plate, 2... Fluorescent lamp, 3... Reading sensor, 4... Amplifier, 5... Binarization circuit, 6...
・Document detection unit, 6A...D flip-flop, 6B・
...Gate circuit, 38

Claims (1)

[Claims] 1. Apply a stripe pattern that is not parallel to the main scanning direction of the original but alternating white and black at the same interval on the scanning light irradiation part of the original holding plate, so that the original cannot be inserted. By sampling the image information from the reading section at the time of insertion or insertion according to the image information transfer lock or the sampling clock set at the predetermined branch, it is possible to identify differences in the reading pattern and determine whether or not the original is inserted. A document detection method characterized by detecting insertion.