JPS5846423B2 - sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting deviation of a sheet from a predetermined position in an apparatus in which the sheet is fed to a predetermined position on a fixing table, pressed, and then discharged.

For example, in a sound transmission machine that records the same sound on multiple magnetic sheets, a strong magnetic field is applied to the master sheet attached to a fixed base by pressing the sound transmission magnetic sheets one on top of the other. Sound conduction is carried out by adding

When performing this sound transmission, the sheet fed toward the fixed base is regulated so that it overlaps the master sheet accurately, and if the sheet deviates from the predetermined position,
It is necessary to promptly detect this and exclude defective recording sheets that have been subjected to sound transmission in a misaligned state.

As a means for detecting the positional deviation of the sheet, there is a method of detecting the front and rear edges of the sheet 1 as shown in FIG.
There is a method of detecting only the front edge (left edge in the figure) of the sheet 2 as shown in the figure.

In FIG. 1, the sheet 1 is conveyed from the rear of the fixing table 3 (from the right side in the figure) toward the fixing table, and its front edge abuts against a stopper 4 fixed on the top surface of the fixing table. It is placed in the position shown.

A master sheet (not shown) is attached to the upper surface of the fixed base 3, and the sheet 1 is superimposed on the master sheet and then pressed by the press head 5.

When the press head 5 descends to perform the above-mentioned pressing action, microswitches S1. In S2, the front and rear ends of the sheet 1 are detected, and the positional deviation of the sheet 1 is detected.

That is, when the seat 1 is in the proper position, both microswitches S1. Both S2 are in the off state, and the sheet 1 after the transfer is discharged in the direction of the arrow 7.

When sheet 1 is too far forward, switch S1 is turned on, and when sheet 1 is too far forward, switch S2 is turned on,
Both switches S1. The positional deviation of the sheet 1 is detected by the logical sum of S2.

In this detection method, microswitch S1. S2
Since the intervals between the sheets are constant, there is a drawback that if the dimensions of the sheet vary in the longitudinal direction, the positional deviation of the sheet cannot be detected correctly.

In addition, when detecting sheet misalignment, if the press action is not performed, for example, if sheet feeding fails and the press head performs blank firing, the state can also be determined. Since malfunctions due to sheet misalignment can be prevented, it is necessary to satisfy this requirement.

An object of the present invention is to provide a device that detects the leading edge of a sheet 1 using a pair of detection switches and detects the positional deviation of the sheet 1 by the exclusive OR of the detection switches, in which the actual sheet feeding corresponding to the press operation of the machine is performed. An object of the present invention is to provide a device capable of detecting only the positional displacement of a sheet at the time when the displacement occurs.

The present invention will be explained below with reference to illustrated embodiments.

In FIG. 2, the sheet 1 is conveyed from the rear (right side in the figure) of the fixed table 11 toward the upper surface of the fixed table, and its front edge abuts against the stopper 12 fixed on the upper surface of the fixed table 11. As a result, the sheet 11 is placed at a predetermined position on the fixed base 11 and overlapped with a master sheet (not shown).

The press head 13 descends from the position shown and presses the sheet 11.
The sheet 1 that has completed its sound transmission is discharged in the direction of the arrow 7 and is detected by the paper discharge detection switch 6.

At the top of the fixed base 11, there is a detection switch S4 for detecting the front edge of the sheet 1. S5 is installed inside each, and both switches S4. S5 is made of, for example, a photoelectric conversion element such as cadmium sulfide, and is arranged so as to be offset from the longitudinal direction of the sheet 1.

In FIG. 3, rain detection switch S4. S5 is fixed base 1
It is covered by a slit plate 14 attached to the slit plate 1, and is turned on by receiving light transmitted through slits 14a and 14b formed in the slit plate 14.

The sheet 1 is conveyed from the bottom to the top on the fixing table 11 in FIG. , both slits N indicated by diagonal lines 15
4a and 14b, the seat 1 is in the proper position, and when it is on the arrow 16 side of this range, it is too far forward, and when it is on the arrow 17 side, it is too far forward. is the detection switch S4. S5
Detected by.

That is, if the seat 1 is too far forward or too far forward, the detection switch S is activated as shown in FIGS.
4. When S5 is simultaneously on or off and in the proper position, the detection switch S4 is turned on when the seat 1 is in the proper position as shown in FIG.
5 is in the off state.

Each of the above detection switches S4. The operation of detecting the positional deviation of the sheet depending on the operation status of S5 will be explained with reference to FIG. 5 and subsequent figures.

In FIG. 5, one terminal of the detection switch S4 is connected to the DC power supply vA and the other terminal is grounded, and when the detection switch S4 receives light and is in the on state, the resistance R
1 is lower than the center terminal potential of the variable resistor VR1, and the potential on the resistor R3 side of the amplifier 22 is lower than that on the R4 side, so the output side of the amplifier 22 is not saturated. The voltage is approximately equal to the current voltage VA.

When the light to the detection switch S4 is cut off and the switch S4 is turned off, its resistance increases and the potential on the resistor R3 side becomes R.
4 side, the output potential of the amplifier 22 falls to the GND level, and the level adjustment transistor Tr1 is cut off.

The collector side of the transistor Tr3 is connected to the DC power supply VB and the exclusive OR circuit 24, and the emitter side is grounded.

Therefore, when the transistor Trl is cut off, the potential on the collector side is high, a bi-level signal is given to the exclusive OR circuit 24, and the detection switch S4 is turned off. When the transistor Trl becomes conductive, a low level signal is given to the exclusive OR circuit 24.

The detection switch 85 side is also configured in a circuit similar to the detection switch S4 described above, and the collector of the transistor T r 2 is connected to the power supply vB and the exclusive OR circuit 24.
rain detection switch S4. S5, amplifier, level conversion transistor and exclusive OR circuit 24
A matching circuit 25 shown within the chain line is constructed.

The exclusive OR circuit 24 includes transistors Trl,
Since the detection signal is output when the signals from Tr2 are simultaneously in the bi-level or low-level state, the rain detection switch S4.
When S5 is on or off at the same time, sheet misalignment is detected, and the detection signal is applied to the NAND circuit 26 to open the gate of the circuit 26, as shown in FIG.

Detection switch S4. If the positional deviation of the sheet is detected only by S5, if the pressing action of sheet 1 is not performed,
That is, even when sound transmission is not performed, the detection switch S4. Since S5 is turned on at the same time, there is an inconvenience that a positional deviation signal is output from the coincidence circuit 25. Also, if the sheet 1 fails to be fed to the fixed base 11 and the press head 13 performs blank printing. has similar disadvantages.

Therefore, when detecting sheet misalignment, the actual sheet misalignment is confirmed by the press signal 28 corresponding to the press operation 27 of the machine and the above-mentioned misalignment detection signal, as shown in FIG. ing.

That is, the above-mentioned press timing signal is applied to the terminal 29 shown in FIG. A trailing edge differential pulse 36 (both shown in FIG. 6) is obtained by the circuit 34 and the knot circuit 35, respectively, and the leading edge differential pulse 33 is applied to the NAND circuit 26.

When the front end differential pulse 33 enters the NAND circuit 26 with the misalignment of the sheet 1 detected by the matching circuit 25, the flip-flop 30 is set, and in this state, the sheet 1 that has finished the pressing operation is removed from the fixed base 11. When the paper is ejected, the ejection detection switch S3 is activated and the NAND circuit 37 is activated.
A sheet position deviation detection signal 38 is taken out to the outside.

In response to this detection signal 38, various means are used to remove the ejected defective sound conductive sheet, for example, by stopping the operation of the sound transmitting device and manually removing the defective sheet, or by using the above positional deviation detection signal. Means is provided to automatically sort out defective sheets.

Note that when the sheet 1 is pressurized, it floats up and the detection switch S4. In order to prevent S5 from malfunctioning, a delay time tdl as shown in Fig. 6 is provided between the press operation of the machine and the start of the press timing signal. The discharge detection switch S3 is activated within the time td2 from when the press timing signal is turned off.
The time t of the press timing signal is such that the pulse 39 of t is generated.

' (see Figure 6) has been adjusted. Flip-flop 30 is reset by a trailing edge differential pulse 36 that occurs when press timing signal 28 is turned off.

Sheet 1 is ejected from the time the flip-flop 30 is set until the press timing signal is turned off.
The misalignment of sheet 1 is detected when the discharge detection switch S3 detects the position of the sheet 1. However, if the discharge detection switch S3 does not operate within the above-mentioned time, it indicates a blank printing state, and the sheet No positional deviation signal is obtained, and the trailing edge differential pulse 36 resets the flip-flop 30 to prepare for the next sheet positional deviation detection.

FIG. 7 shows another embodiment of the matching circuit 41 in which the sheet 1 is displaced as shown in FIG. 4a or c and the detection switch S4. When S5 is simultaneously off or on, the potential v1. (2) so that vl>v2, and when the detection switch S4 is on and the detection switch S5 is off, vl
The value of variable resistor R3 is adjusted so that <v2.

Therefore, when there is a misalignment of the sheet 1 as shown in FIG. It will be done.

Using this detection signal 45 and the above-mentioned press timing signal, it is possible to detect sheet positional deviation similar to the coincidence circuit 25 in FIG.

According to the present invention, the leading edge of the sheet is detected by a pair of detection switches that are slightly shifted in the front and back direction of the fixing base, and the positional shift of the sheet is detected by the exclusive OR of both switches. By using the timing signal, the paper ejection detection signal, and the above-mentioned positional deviation detection signal, only the actual sheet positional deviation signal is detected, regardless of the length of the sheet. , generation of positional deviation signals can be prevented.

[Brief explanation of the drawing]

Figure 1 is a side view of a conventional sheet misalignment detection device;
The figure is a side view of a sheet misalignment detection device to which the device of the present invention is applied, FIG. 3 is a plan view of the detection switch mounting section, and FIG. 4 is a plan view showing the positional relationship between the sheet leading edge and the detection switch. , FIG. 5 is an electric circuit diagram of a sheet position deviation detection device showing one embodiment of the present invention, FIG. 6 is a time chart in the electric circuit, and FIG. 7 is an electric circuit showing another embodiment of the matching circuit. It is a diagram. 11... Fixed stand, 1... Seat, S4
．． S5... Sheet leading edge detection switch, S3... Sheet discharge detection switch 25°41... Coincidence circuit.

Claims (1)

[Claims] 1 A device that feeds and presses sheets one by one to a predetermined position on a fixed table, which is a device that supplies sheets one by one to a predetermined position on a fixed table and presses them, and the sheets are placed on the fixed table or press head with a certain interval shifted in the front and back direction of the sheet. In a sheet positional deviation detection device having a pair of detection switches for detecting the leading edge of the sheet and a matching circuit for detecting when the pair of detection switches is deviated from the above-mentioned certain range, the sheet is pressed out of position. The apparatus is characterized by comprising positional deviation suppression signal output means for outputting a positional deviation signal of the matching circuit only when a sheet is detected by a sheet discharge detection means provided in a sheet discharge path in a sheet discharge direction from a suppression area. Sheet misalignment detection device.