JP2665156B2 - Paper jam detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper jam detecting apparatus for use in a printer for printing by mounting cut paper cut into a predetermined size on a platen.

[0002]

2. Description of the Related Art A predetermined size (for example, A4 size or B5 size)
A conventional printer that prints by cutting a printing paper (a so-called cut paper) cut into a size into a platen is used. A paper jam detection device (a paper jam sensor) for detecting when the printing paper (paper) is jammed ) Are very rare, and those equipped with a paper jam sensor must detect paper jam until the transmission of print data is completed, that is, until a series of printing operations is completed. The configuration is not possible.

[0003]

As described above, most of the conventional printers cannot detect when a paper jam occurs, and the printer that can detect the paper jam is also capable of detecting the print data. Since the paper jam cannot be detected until the paper has been sent, if a paper jam occurs during printing, the print data continues to be ejected even if the paper is not being sent normally, and There is a problem that the printing operation cannot be stopped simultaneously with the occurrence of a jam.

[0004]

According to the present invention, there is provided a paper jam detecting apparatus comprising: two circular magnets fixed in parallel inside a cylindrical platen and magnetized in the same direction; An annular member provided therebetween, an axis fixed to a printer passing through the centers of the two circular magnets and the annular member, and an annular member disposed in parallel with the two circular magnets; A conductor bar for fixing a member to the shaft, and a detection circuit for outputting a detection signal when an electromotive force generated in the conductor bar when the platen rotates and a feed signal for rotating the platen are input. With, and
As a detection circuit, a transistor operated by an electromotive force generated in the conductor bar when the platen rotates, a feed signal for rotating the platen, and an output signal of the transistor are input to output a detection signal. And a detection circuit having an AND circuit.

[0005]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view taken along line AA of the embodiment of FIG. 2, FIG. 2 is a plan view showing an embodiment of the present invention, and FIG. 3 is a circuit diagram showing an example of a detection circuit of the embodiment of FIG. It is.

In FIGS. 1 and 2, a cylindrical platen 1 has two circular magnets 2 and 5 fixed inside. The circular magnets 2 and 5 are magnetized in the same direction (for example, the north pole on the upper side and the south pole on the lower side), and are fixed to the platen 1 perpendicularly to the axis of the platen 1. Therefore, the circular magnet 2 and the circular magnet 5 are parallel.

Between the circular magnets 2 and 5, an annular ring member 4 is provided in parallel with them. The shaft 6 passes through the centers of the circular magnets 2 and 5 and the annular member 4 and is fixed to a printer on which the platen 1 is mounted. The ring member 4 is connected to and fixed to the shaft 6 by a conductor rod 3 disposed in parallel with the circular magnets 2 and 5. Therefore, when the platen 1 rotates to convey the printing paper, the circular magnets 2 and 5 rotate integrally with the platen 1, but the annular member 4, the conductor rod 3 and the shaft 6
Does not rotate.

In the paper jam detecting device configured as described above, a uniform magnetic flux B is generated between the circular magnet 2 and the circular magnet 5. When the platen 1 is rotated in this state, since the conductor bar 3 crosses the magnetic flux B, an electromotive force V is generated between the terminal 7 connected to the shaft 6 and the terminal 8 connected to the annular member 4. Occurs. The magnitude of the electromotive force V at this time is V = １ ／ · Br ² ω, where r is the length of the conductor bar 3 and ω is the angular velocity of rotation of the platen 1.

The terminals 7 and 8 are connected to a transistor 9 via a resistor R as shown in FIG.
Therefore, when an electromotive force V is generated between the terminals 7 and 8,
The transistor 9 is turned on, and outputs the output signal 13. The output signal 13 is input to one input terminal of the AND circuit 10, and the feed signal 11 which is a drive signal for rotating the platen 1 is input to the other input terminal of the AND circuit 10. Therefore, when the platen 1 is rotating normally, the electromotive force V is generated, and the detection signal 12 is output from the AND circuit 10. However, when the paper jam occurs, the electromotive force V is normally generated. Therefore, the detection signal 12 is not output. For this reason,
By monitoring the detection signal 12, the occurrence of paper jam can be determined at the time of occurrence.

[0011]

As described above, in the paper jam detecting apparatus of the present invention, two circular magnets are provided inside the platen to generate a uniform magnetic flux between them, and the two circular magnets are detected. When a platen is rotated by providing a conductor bar between them to generate an electromotive force across the magnetic flux, the generated electromotive force and a feed signal for rotating the platen are input to a detection circuit, and the output signal is output. By monitoring, there is an effect that the occurrence of paper jam can be determined at the time of occurrence, and therefore, when paper jam occurs,
There is an effect that the printer can be stopped immediately.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA of the embodiment of FIG.

FIG. 2 is a plan view showing one embodiment of the present invention.

FIG. 3 is a circuit diagram illustrating an example of a detection circuit according to the embodiment of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Platen 2 Circular magnet 3 Conductor rod 4 Ring member 5 Circular magnet 6 Shaft 7 Terminal 8 Terminal 9 Transistor 10 AND circuit 11 Feed signal 12 Detection signal 13 Output signal

Claims (2)

(57) [Claims] 1. Two circular magnets fixed in parallel inside a cylindrical platen and magnetized in the same direction; an annular member provided between the two circular magnets; A shaft fixed to the printer passing through the center of the circular magnet and the annular member, a conductor bar arranged in parallel with the two circular magnets and fixing the annular member to the axis, and the platen A paper jam detection device, comprising: a detection circuit that outputs a detection signal when an electromotive force generated in the conductor bar when the rotator rotates and a feed signal for rotating the platen is input. 2. A transistor which operates by an electromotive force generated in a conductor bar when a platen rotates, a feed signal for rotating the platen and an output signal of the transistor, and outputs a detection signal. The paper jam detection device according to claim 1, further comprising a detection circuit having a circuit.