JPS5975379A - Pick-mistake detecting system - Google Patents

Abstract

PURPOSE:To prevent the generation of a wrong pick-mistake signal by producing the pick-mistake signal when a prescribed period of time elapses after detecting a feeding error of a sheet. CONSTITUTION:An output E' obtained by delaying the output of an AND circuit 8' by a counter 7 is used as a pick-mistake signal. The release of a pick-stop signal, i.e. the retrial of a sheet feeding action is carried out with an output obtained by delaying the pick-mistake signal E' by a prescribed time through a delay circuit 12. Therefore the count value of the counter 7 for a period from generation of the output ''1'' of the circuit 8 to the generation of an output of the counter 7 is set with consideration of a stop delay time caused by the inertia of a roll 3. Thus, the generation of a wrong pick-mistake signal owing to the stop delay time of the roll 3 is prevented.

Description

Detailed Description of the Invention (A) - Technical Field of the Invention The present invention relates to a sheet pick mechanism used in a sheet information medium processing device such as an optical character reader (OCR) or an optical mark reader (OMR). 0 (13) Technical Background Sheet-like information media processing devices and KOCR/OMR are extremely convenient means of inputting data to converters, and their field of use has recently expanded rapidly with the momentum of office automation. There is.

In these devices, sheets are loaded in a hopper and fed out one by one by a sheet pick mechanism. There is also an increased chance that damaged sheets such as bent or bent sheets will be mixed in, leading to an increase in sheet feeding errors, i.e., sheet pick mistakes, which is a major cause of reduced operating rates for OCR, OMR, etc. ing.

(0 Prior Art and Problems Figure 1 shows a configuration diagram of a sheet pick mechanism. 1 is a sheet, 2 is a hopper for loading the sheet 1, and 3 is an intermittently rotated direction as shown by the arrow to pick up the sheet on the hopper 2. 4 is a conveyance roller provided at the beginning of the sheet conveyance path, and 5 is a sensor that detects whether or not the sheet 1 has been conveyed onto the sheet conveyance path.

Fig. 2 shows a block diagram of a conventional example of a pick error detection system, and 6 indicates a clock C starts counting when a drive signal for the feeding row 23, that is, a pick signal A is issued, and generates an output when a predetermined number is counted. a first counter that
7 is a second counter that starts counting the clock C when the AND circuit (described later) outputs 1, and generates an output when a predetermined number is counted; 8 is the output of the first counter 6 and the sensor 5; An AND circuit 9 obtains an AND with the generated sense signal B, and an AND circuit 8 is connected to 11. 10 is a comparison circuit that generates an output when the count value of the third counter 9 reaches a predetermined value; 11 is a comparison circuit that is set by the output of the AND circuit 8; This is a flip-flop that is reset by the output of the carantuff. Loaded sheet 1
A predetermined time determined by the distance from the tip of the sheet 1 to the sensor 5 is required, and the first counter 6 is provided to obtain this predetermined time. 0 is provided so that the sense signal B becomes FIJ when the sensor 5 has not reached the sensor 5. In other words, the first counter 6
Even if the predetermined time given by
When the tip of the sensor 5 has not reached the AND circuit 8
generates a pick miss signal E.

The flip-flop 11 is set by the AND circuit 8, and at this time, a big stop signal F is issued to the feeding roller 3. Further, when a predetermined time given by the second counter 7 has elapsed since the pick signal A was issued, the 7-lip flop 11 is reset, and at this time the pick stop signal F is released.

That is, as mentioned above, the feeding roller 3 feeds out the sheet 1 by the frictional force between it and the sheet 1, but the big miss signal E is generated by utilizing the fact that the coefficient of static friction is larger than the coefficient of dynamic friction. When this happens, the rotation of the feed roller is temporarily stopped and the sheet feeding operation is repeated again. Even if the sheet feeding operation is repeated in this way, the sheet 1
If the tip of the sensor 5 does not reach the sensor 5, a pick miss signal E is generated each time, but the third counter 9 counts this, and when the count value reaches a predetermined value, the comparator circuit 10 outputs a pick miss display signal. Generate G.

However, even when the big stop signal F is issued, the feed roller 3 does not stop rotating immediately, but gradually stops while continuing to rotate for a short period of time due to inertia, and during this time, the feed roller 3 (C) 1 is carried out. There are many things that happen. However, the conventional pick miss detection method generates a big miss signal E even in such a case, and therefore OCR/
There was a problem that the processing capacity of OMR etc. was reduced.

(2) Purpose of the Invention The purpose of the present invention is to prevent the generation of erroneous big miss signals in the seat pick mechanism.

(G) Structure of the Invention The pick error detection method according to the present invention is based on a sheet pick mechanism that feeds sheets stacked in a hopper one by one and sends them out to a sheet conveyance path, after detecting a sheet feed error and then waiting for a predetermined period of time. Embodiments of the Invention The gist of the present invention will be explained in detail with reference to embodiments.

FIG. 3 shows a block diagram of an embodiment of the present invention, in which the same symbols as the conventional example in FIG. 2 indicate the same objects, and 9' counts the number of times the second counter 7 outputs a comparator circuit 10' that generates an output when the count value of the fourth counter 9' reaches a predetermined value;
11' is a flip-flop circuit that is set by the output of the AND circuit 8 and reset by the output of the delay circuit described later, and 12 is a delay circuit that delays the output of the second counter 7 for a predetermined period of time.

That is, FIG. 3 shows an example in which the present invention is applied to the conventional example shown in FIG.
The output E' obtained by delaying the big miss signal E' is used as a pick miss signal, and the output of the big miss signal E' delayed by a predetermined time by the delay circuit 12 is used to cancel the pick stop signal F, that is, to retry the sheet feeding operation. .

Therefore, the count number of the second counter 7 from when the AND circuit 8 generates the output '1- until the second counter 7 generates the output is set in consideration of the stop delay time due to the inertia of the feeding roller 3. By doing so, it is possible to prevent the generation of an erroneous big miss signal that occurs during the stop delay time of the feeding row 23.

(G) As described in detail, according to the present invention, generation of an erroneous big miss signal in the pick miss detection circuit is prevented, and OCR
- The operating rate of sheet-like information processing devices such as OMR can be improved.

[Brief explanation of drawings]

FIG. 1 shows a configuration diagram of a sheet pick mechanism, in which 1 is a sheet, 2 is a hopper, and 3 is a feeding roller. Further, FIG. 2 is a block diagram of a conventional example of a pick error detection method, and FIG. 3 is a block diagram of an embodiment of the present invention.

Claims (1)

[Claims] In a sheet pick mechanism that feeds sheets loaded in a hopper one by one and sends them to a sheet conveyance path, the sheet pick mechanism generates a sheet feeding error signal when a predetermined time elapses after detecting the sheet feeding pb. Sheet pick error detection method 0