JPH01214529A - Sheer feed mechanism - Google Patents

Abstract

PURPOSE:To improve the efficiency of work by providing a circuit for suppressing the detection signal of a level detector when a sheet is feeding out and operating a table lifting/lowering mechanism upon finish of sheet feeding operation, thereby eliminating trouble such as mis-feeding. CONSTITUTION:When the final cut sheet 2 separates from a pick roller 4, the pick roller 4 reaches to a lower limit position B and a level detector 9 detects such condition to produce a detection signal immediately. Since the end of the cut sheet 2 has not reached to a feed roller 10 immediately after detection, if a motor 111 is driven under this condition feeding of the cut sheet 2 is blocked thus causing misfeed. In order to prevent misfeed, a delay circuit 13 delays provision of a detection signal to a motor drive circuit 114 until the end of the cut sheet 2 reaches to the feed roller 10 and suppresses operation of a table lift mechanism 11, which is operated when the end of the cut sheet 2 reaches to the feed roller 10.

Description

[Detailed Description of the Invention] [Summary] Regarding the paper feeding mechanism of a printing device that uses cut paper, the operation of the table lifting mechanism of the paper feeding mechanism that detects the level of the cut paper and maintains the level at a predetermined level is The purpose of this system is to stop the feeding mechanism and eliminate errors in paper feeding.It is equipped with a table on which cut sheets such as single forms are placed, a pick roller that feeds out the cut sheets one by one from the top, and a level detection system. A paper feeding mechanism including a level detector for detecting a lower limit level and a table lifting mechanism for raising a table in response to detection of a lower limit level of the level detector, further comprising a circuit for suppressing a detection signal from the level detector during paper feeding operation. and the table lifting mechanism is configured to operate after the sheet feeding operation is completed.

[Industrial application field]

The present invention relates to a paper feeding mechanism for a printing apparatus that uses cut paper, and particularly to a paper feeding mechanism that suppresses the operation of a table lifting mechanism while paper is being fed.

In the field of information processing, printing devices are widely used as information output devices. Some of these printing devices use printing paper in the form of a single form (hereinafter referred to as cut paper). This type of printing device uses a paper feed mechanism that feeds paper. This paper feeding mechanism places cut paper on a paper loading table (hereinafter referred to as a table), and is equipped with a level detector that detects the upper limit level. If the table is raised inside the machine, there is a risk that paper feeding errors may occur.

[Conventional technology]

Figure 2 is a diagram explaining a conventional paper feeding mechanism.
FIG. 3A is a schematic perspective view, and FIG. 2B is a side view of a main part explaining the operation of the level detector.

In the figure, a table 1 on which a cut sheet 2 such as a single form is placed is connected to a motor 111, a pair of pulleys 112, and a wheel.
- 113, and is attached to a heald 113 of a table elevating mechanism 11, and is raised and lowered by the drive of a motor 111.

A pick roller 4 fixed to a rotating shaft 3 that feeds the cut paper 2 to a printing section (not shown) is in contact with the upper surface of the stacked cut sheets 2, and the rotating shaft 3 is intermittently rotated by a drive source (not shown). Then, the cut paper 2 is sent out.

At both ends of the pick roller 4, one end of the support fitting 5 is attached to the rotation shaft 3.
The other end of the support fitting 5 is fixed to a support shaft 6 supported by a bearing 7.

One end of a light shielding plate 8 is fixed to one end of the support shaft 6, and the other end of the light shielding plate 8 is located between the light emitting and light receiving elements constituting the level detector 9 for the cut paper 2. The motor 111 is configured to block or open one optical path between the emitter and one light-receiving element. When the optical path is blocked, the motor 111 does not operate. However, when the optical path is opened, that is, when the light shielding plate is removed from the optical path, the level detector 9
The output signal operates the motor drive circuit 114 via the cable 12, and the motor 111 is driven in the direction of the arrow, thereby driving the pulley 112 and the gears 1 to 113 in the direction of the arrow, thereby raising the table 1.

To explain this operation in more detail, as the pick roller 4 sequentially feeds out the cut sheets 2 according to the print information, the pick roller 4 moves from the upper limit position of the cut sheet 2 to the lower limit position B using the support shaft as a fulcrum and moves the support metal fitting 5 and descend in the direction of the arrow.

Therefore, the light shielding plate 8 fixed to the support shaft 6 also rotates in the direction of the arrow and comes off the level detector 9, unblocking the optical path between the light emitting and light receiving elements, and the output signal causes the motor 111 to
is driven and table 1 is raised. As a result, when the upper surface of the cut paper 2 reaches the upper limit position A, the pick roller 4 also rises, and the light shielding plate 8 returns to its original position via the support fitting 5, thereby blocking the optical path of the level detector 9. Therefore, the motor 11 stops and the table also stops.

[Problem to be solved by the invention]

In the above-mentioned conventional paper feeding mechanism, when the surface of the cut paper 2 reaches the lower limit position B, the big roller 4 also lowers, and during the paper feeding operation, the table lifting mechanism is operated by the output signal of the level detector 9. Therefore, there was a problem that paper feeding errors could occur.

The present invention solves the above-mentioned problems and provides a paper feeding mechanism that suppresses the operation of the table lifting mechanism even if the level detector detects the lower limit position B during paper feeding.

[Means to solve the problem]

This invention includes a table on which cut sheets such as single forms are placed, a pick roller that feeds out the cut sheets one by one from above, a level detector that detects the level, and a lower limit level of the level detector. In a paper feed mechanism equipped with a table lifting mechanism that raises the table in response to detection,
The above-mentioned problem is solved by providing a circuit that suppresses the detection signal of the level detector during the paper feeding operation, and by activating the table lifting mechanism after the paper feeding operation is completed.

[Function] In this paper feeding mechanism, even if the level detector detects the lower limit level, the detection output is suppressed and the table lifting mechanism does not operate while the bin roller is feeding the cut paper, so that the paper feeding mechanism does not feed the cut paper. Mistakes and double fees can be prevented.

〔Example〕

FIG. 1 is a diagram illustrating an embodiment of the present invention.
) is a schematic perspective view, and (b) is a side view of a main part explaining the operation of the level detector.

In FIG. 1, the paper feeding mechanism of the present invention includes a table and a pick roller, similar to the conventional example shown in FIG.

It is equipped with a support shaft, a light shielding plate, a level detector, a table lifting mechanism, etc., and is characterized in that a delay circuit 13 is provided between the level detector 9 and the motor drive circuit 114 of the table lifting mechanism. Therefore, the same reference numerals as in FIG. 2 are given to the parts other than the delay circuit 12, and the explanation of these parts will be omitted here.

When the level detector 9 detects the lower limit position B of the cut paper 2, the delay circuit 13 that characterizes the present invention delays the detection signal by a predetermined time and sends it to the motor drive circuit 114. That is, when the last cut sheet 2 leaves the pick roller 4, the pick roller 4 reaches the lower limit position B, and the level detector 9 detects this state and immediately outputs a detection signal, but immediately after the detection, the pick roller 4 reaches the lower limit position B. Since the end of the cut paper 2 has not reached the feed roller 10, the motor 111
When the table 1 is raised by driving the cut paper 2 that is being fed out
This obstructs the feeding of the material and causes feeding errors. To prevent this, the delay circuit 13 is configured so that the end of the cut paper 2 is connected to the feed roller 10.
The sending of the detection signal to the motor drive circuit 114 is delayed until the end of the cut sheet 2 reaches the feed roller 10, and the operation of the table lifting mechanism 11 is inhibited until the end of the cut sheet 2 reaches the feed roller 10. The table elevating mechanism 11 is operated in the state in which the table is reached.

In addition to the above embodiments, the following configuration can be applied as a circuit for suppressing the detection signal of the level detector. That is, the paper feeding operation of the feed roller is detected, and the level detection signal is not outputted during paper feeding.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, since the table lifting mechanism does not operate during sheet feeding, problems such as sheet feeding errors can be eliminated, and this is extremely effective in improving work efficiency.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating an embodiment of the present invention.
1(b) is a side view of the main part explaining the operation of the level detector, and FIG. 2 is a diagram explaining the conventional paper feeding mechanism.
a+ is a schematic perspective view, and (b) is a side view of a main part explaining the operation of the level detector. In the figure, 1 is a table, 2 is a cut paper, 3 is a rotating wheel, 4 is a pick roller, 5 is a support bracket, 6 is a support shaft, 7 is a bearing, 8 is a light shielding plate, 9 is a level detector, 10 is a feed Roller, 11 is table lifting mechanism, 12 is cable, 1
3 is a delay circuit, 111 is a motor, 112 is a pulley, 11
3 represents a heald, and 114 represents a motor drive circuit.

Claims (1)

[Claims] Table (1) on which cut sheets (2) such as single forms are placed
, a pick roller (4) that feeds out the cut paper (2) one by one from the top, and a level detector (4) that detects the level.
9), and a table lifting mechanism (1) that raises the table (1) in response to the lower limit level detection of the level detector (9).
11), a circuit (12) is provided to suppress the detection signal of the level detector (9) during the paper feeding operation, and the table lifting mechanism (11) is operated after the paper feeding operation is completed. A paper feeding mechanism characterized by: