JPH0443062A - Earth for sheet feed tractor - Google Patents

Abstract

PURPOSE:To prevent the destruction of a semiconductor integrated circuit due to static electricity without incorporating a protective mechanism in a circuit by bringing the contact element of the earth for a sheet feed tractor into contact with the switch lever of a microswitch and bringing the other contact element thereof into contact with a support shaft. CONSTITUTION:The earth 1 for a sheet feed tractor is supported by the coil receiving pin 42 of a switch cover 4 and a contact element A11 is brought into contact with the switch lever 21 of the microswitch 2 mounted on the switch cover 4. The switch cover 4 is mounted on a tractor case 5 to form the sheet feed tractor. A support shaft 3 is fitted in support shaft holes 41, 51. At this time, the contact element B12 of the earth 1 for the sheet feed tractor comes into contact with the support shaft 3. The earth 1 for the sheet feed tractor is composed of a coil spring and the contact elements A11, B12 are not separated from the switch lever 21 and the support shaft 3 by the recovery force of the earth 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a grounding device attached to a sheet feed tractor of a printer equipped with a paper breakage detection mechanism.

[Background Art and Technical Problems to be Solved] In recent years, printing devices that print output information (hereinafter referred to as printers) have improved their performance by having many semiconductor integrated circuits inside.

However, semiconductor integrated circuits are small and delicate, and there are restrictions on how they can be used, and voltages that greatly exceed the rated voltage of the semiconductor integrated circuit are often applied, resulting in short circuits.
Such applied voltages should be avoided. However, while the printer is in use, an excessive voltage may be applied due to static electricity carried by people or paper. Therefore, a protective measure has been taken in which the printer body is always grounded while in use to prevent excessive voltage from being applied to the circuit due to static electricity. However, printers equipped with a convenient paper-out detection mechanism detect the presence or absence of paper depending on whether the switch lever of a microswitch connected to the printer's internal circuit is in contact with the paper or not, so even if the printer body is grounded, , static electricity on paper,
Alternatively, when a person touches a switch lever, static electricity flows into the printer's built-in semiconductor integrated circuit via the microswitch, destroying it.

Conventionally, a method has been proposed in which a capacitor is incorporated into the circuit to prevent damage to semiconductor integrated circuits caused by electrostatic current. In other words, the capacitor's resistance to voltage changes is used.

However, when a capacitor is incorporated into a circuit, the degree of freedom in circuit design is hampered by the capacitor's resistance and capacitance limits, as well as by securing the installation location, which is one of the factors that hinders the improvement of printer performance.

The present invention has been made in view of the above-mentioned shortcomings of conventional anti-static protection mechanisms.The present invention has been made in view of the above-mentioned drawbacks of conventional anti-static protection mechanisms. The technical problem is to provide a means to prevent semiconductor integrated circuits from being destroyed by

[Means adopted to solve the problem]

The means adopted by the present inventor to solve the above problem will be explained below with reference to the accompanying drawings.

That is, a sheet feed tractor ground 1 made of an elastic conductor has a contact A11 and a contact B12 at both ends,
The contact A11 is in contact with the switch lever 21 of the microswitch 2, and the contact B12 is in contact with the support shaft 3 disposed on and in contact with the printer body, thereby incorporating it into the circuit. We provided a ground for sheet-feed tractors that provides anti-static protection.

〔Example〕

The present invention will be described below based on embodiments shown in the accompanying drawings.

A ground 1 for a seat-feed tractor, which is a stainless steel coil spring equipped with a contact A11 and a contact B12 at both ends, has a coil bearing of a switch cover 4 supported by a pin 42, and is provided on the switch cover 4. The contactor A11 is brought into contact with the switch lever 21 of the microswitch 2.

The switch cover 4 is attached to the tractor case 5,
Form a sheet feed tractor. The support shaft 3 is fitted into the support shaft holes 41 and 51. At this time, contact B of earth 1 for note feed tractor
12 is in contact with the support shaft 3. Further, the seat feed tractor ground 1 is a coil spring, and its restoring force prevents the contact A11 and the contact B12 from separating from the switch lever 21 and the support shaft 3. The auxiliary pin 43 provided on the switch cover 4 has the function of holding the contact B12 in a position where the support shaft 3 can be easily inserted when the support shaft 3 is not inserted into the sheet feed tractor. The support shaft 3 is where the contact B12 is running diagonally.
This is to make the contact B12 easier to insert and to prevent excessive force from being applied to the contact B12 during insertion.

It is assumed that the sheet feed tractor ground 1 is disposed on the sheet feed tractor as described above, and this sheet feed tractor is attached to the printer. The printer body is grounded. At this time, the switch lever 21 is grounded.

That is, when static electricity charged by paper or static electricity carried by a person flows into the switch lever 21, the contact A1
1. Ground for sheet feed tractor 1, contact B1
2. Static electricity flows to the ground via the support shaft 3 and the printer body.

Although the present embodiment has been described above, the present invention is not limited to this embodiment, and various modifications can be made within the scope of the claims. In particular, modifications such as making the ground for the sheet feed tractor from a plate spring are included within the scope of the invention.

[Effects of the present invention]

As described above with reference to the embodiments, according to the ground for a sheet feed tractor of the present invention, anti-static protection can be achieved in a printer equipped with a paper break detection mechanism without incorporating a protection mechanism into the internal circuit. This removes restrictions on circuit design. It's also much cheaper than traditional methods of incorporating diodes into circuits.

As described above, the ground for sheet feed tractors of the present invention has high industrial utility value.

[Brief explanation of drawings]

FIG. 1 is an exploded view of a sheet feed tractor equipped with a ground for the sheet feed tractor according to the present embodiment. Patent applicant: Sakase Chemical Industry Co., Ltd. Agent, Patent attorney: Koji Togawa tlE1 Figure 5... Tractor case 11, Contact A 12... Contact 8 21, Switch lever 41... Support shaft hole 42, Coil receiver Pin 43: Auxiliary pin 5 support shaft hole

Claims (1)

[Claims] In a sheet feed tractor equipped with a paper-out detection mechanism that detects when the paper is out by swinging the switch lever 21, the switch lever 21 of the microswitch 2 that is in contact with the paper is always elastically connected to the switch lever 21, which is made of an elastic conductor. A ground for a sheet feed tractor characterized by having a contact A11 in contact with the printer body and a contact B12 in elastic contact with a support shaft 3 disposed on the printer body and in contact with the support shaft 3.