JPS5952133B2 - Paper feed control circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a paper feed control section of an optical character reader (hereinafter abbreviated as OCR) among input devices for an electronic computer.

[Background of the invention]

OCR paper feed control can be broadly classified into two types: methods that stop the form at the reading unit and methods that read the form while it is running.Usually, the former is a page reader type and the latter is a document reader type. Compatible.

FIG. 1 shows a typical OCR paper feeding mechanism, and the movement of a form will first be explained using this mechanism.

The forms stacked in the hopper 1 are sent out by the pickup roller 2, and after being controlled by the separator roller 3 so as not to feed two sheets, they pass through detectors 4 and 5 on the travel path and are transferred to a page reader type. When the characters to be read reach the bottom of the reading head section 6, the document is stopped and the characters are read, and after the reading is completed, the document is run again. Furthermore, in the document reader type, characters are read while the form is running. The form is further detected by detector 7.
, 8, and are sorted into stackers 10 and 11 by the stacker selection mechanism 9 according to the reading results. The above-mentioned form is conveyed by driving the pick-up roller 2, separator roller 3, and a group of conveying rollers on the travel path by a motor or the like which is omitted in FIG.

Further, the rotation and stop of the motor is controlled by using a control means such as a microprocessor, and by outputting logic levels ``1'' and ``0'' as running signals.Each detector on the J conveyance path consists of a combination of a light-emitting element and a light-receiving element.In such OCR paper feeding control, if a form becomes abnormal on the travel path and becomes impossible to travel (jam), the jam is immediately detected and the motor is activated. It needs to be stopped.

The normal method for detecting a jam in a document reader type is to check the time it takes for the leading edge of the form to pass through one detector, and the time required from passing one detector to passing the next. However, if it does not pass after a predetermined period of time, it is detected as a jam. Therefore, this method cannot be directly applied to a page reader type in which a form is temporarily stopped. [Object of the Invention] The object of the present invention is to provide a paper feed system that is capable of detecting jams in both document reader types in which forms are read while running and page reader types in which forms are read while paused. The purpose is to provide a control circuit.

[Summary of the invention]

The present invention uses the simplest and most reliable method of jam detection, which is to check the time it takes for a form to pass through a detector.

A feature of the present invention is that the above-mentioned time check is omitted during a temporary stop while reading a form so that it can be applied to a page reader type as well. [Embodiment of the Invention] An embodiment of the invention is shown in FIG.

FIG. 2 shows an example of jam detection by the detector 4 of FIG. The count-up signal 33 of the counter 21 is the AND of the counting clock pulse 31, the output 32 of the detector 4, and the running signal 30 representing the running state of the form. That is, when the running signal 30 is "゜1゛", the detector 4
When the output 30 of is ゜゜1'', the logical product of the AND circuit 24 is taken and the count-up signal 33 is output.Therefore, the counter 21 starts counting the clock panorez 31 from the time the form reaches the detector. Counting continues while the form is blocking the detector 4, but while the form is temporarily stopped, the running signal 30 is ゜“0゜”, so the clock pulse 3 is
A count of 1 is not performed. On the other hand, a numerical value (time specification value) obtained by dividing the jam detection time by the blackout pulse 31 is given to the register 22 in advance by, for example, the control section 2 of the microprocessor, and this output and the output of the counter 21 are input to the comparator 23. When the counted value of the counter 21 exceeds the specified time value, it is detected as a jam and a jam detection signal is output. The jam detection signal is sent to the control section, and rotation of the motor is stopped. The output of the detector 4 is input to the reset terminal R of the counter 21, and is set when the output of the detector 4 is ``0'', that is, there is no form on the detector.

The jam detection described above is similarly performed in the other detectors 5, 7, and 8.

〔Effect of the invention〕

The present invention enables document reader types and page
Jam detection common to all reader types can be realized at low cost.

You can also use the same machine as a document reader to read pages and pages.
If the function as a reader is to be provided, it can be easily switched without any changes.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a typical OCR paper feed mechanism, Figure 2
The figure is a block diagram showing one embodiment of the paper feed control circuit of the present invention. 1... Hopper, 2... Pick up roller, 3... Separator roller, 4, 5, 7,
8...Detector, 6...Reading head,
9... Statzka selection mechanism, 10, 11...
...Statska, 21...Counter, 22...
... Lujistar, 23... Comparator, 24...
・Logic product circuit.

Claims (1)

[Claims] 1. A detector that detects the presence or absence of a form on a running road, a circuit that outputs a clock pulse when the detector is detecting a form while the form is running, and a counter that counts the clock pulses from the circuit. a memory circuit that stores a designated time value for jam detection; a comparator that compares the contents of the memory circuit with the counted value of the counter and outputs a jam detection signal when the counted value of the counter exceeds the content of the memory circuit; A paper feed control circuit characterized by comprising: