JPH04301478A - Printer - Google Patents

Abstract

PURPOSE:To prevent warpage of paper and prevent effectively jam from occurring without making an overall size large and a printing range narrow in a paper jam preventing mechanism for a dot serial type printer. CONSTITUTION:When a print head 7 is on the left side, a link 12' is driven by operation of a coil spring, a paper guide L10 is dissociated from a platen, and a paper is held by a card holder 2. On the right side, an electromagnetic solenoid 13 is driven so as to hold the paper by a paper guide R11. When the head 7 is on the right side, the paper guide R11 is dissociated and the paper is held by the card holder 2 so as to hold the left thereof by the paper guide L10 in the same manner. When the head 7 is at the center, the paper can be held by the paper guides L10 and R11.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer having a dot serial type print head, and more particularly to a paper jam prevention mechanism in a conveyance path of a print medium.

0002

2. Description of the Related Art A conventional dot serial type printer will be explained with reference to the drawings. FIG. 4 is a perspective view showing a conventional example. Print medium 1 passes between card holder 2 and platen 3. A serial type print head (hereinafter referred to as P/H 7) is arranged on a carrier frame 6 supported by a front shaft 4 and a rear shaft 5. The carrier frame 6 was driven by a stepping motor 9 via a belt 8, and had a mechanism in which printing was performed by a P/H 7.

0003

[Problems to be Solved by the Invention] In the conventional printer described above, printing is performed by holding down the bulge of the printing medium paper with a card holder attached to the carrier frame in which the P/H is arranged. If you try to suppress the entire bulge of the card holder, there is a problem in that the length of the card holder becomes longer and the external dimensions of the printer become larger.

[0004] Furthermore, printers whose external dimensions cannot be increased have the problem of narrowing the printing range.

[0005] If the above measures cannot be taken, the length of the card holder will be shortened, but in that case, the length of the card holder is not long enough, and the printing medium paper other than the part where printing is performed Since there is no presser foot, the paper bulges and paper jams occur.

The present invention solves the above problems, reduces the external dimensions of the printer, eliminates the need to narrow the printing range,
To provide a printer having a mechanism for restraining paper to eliminate bulges and preventing paper jam.

[0007]

Means for Solving the Problems The paper jam prevention means for a printer of the present invention comprises a paper guide in a platen section and means including an actuator that changes the position of the paper guide depending on the position of the print head.

[0008] The actuator works depending on the position of the print head, and by operating the paper guide connected by a link, it is possible to suppress the bulge of the paper and prevent paper jams.

[0009]

[Example] Next, regarding an example of the printer of the present invention,
This will be explained with reference to the figures.

FIG. 1 is a perspective view of a printing mechanism of a printer incorporating a paper jam prevention mechanism according to an embodiment of the present invention. FIG. 2 is an enlarged side view of essential parts for explaining the paper jam prevention mechanism of the printer of the present invention and its operation.

In FIG. 1, a print medium paper 1 passes between a card holder 2 and a platen 3, and is transported through a front shaft 4,
A serial dot impact print head (hereinafter referred to as P/H) 7 is attached to a carrier frame 6 supported by a rear shaft 5. The carrier frame 6 is connected to a stepping motor 9 via a belt 8.
Driven by The platen 3 includes a paper guide L10 and a paper guide R11, each connected to a link 12 and driven by an electromagnetic solenoid 13. A sensor plate 14 is attached to the lower part of the carrier frame 6, and a non-contact optical sensor L15 and a non-contact optical sensor R16 are disposed to detect the position of the carrier frame 6 by the arrival of the sensor plate 14.

The main parts of the jam prevention mechanism and its operation will be explained below with reference to FIG. Paper guides L10 and R11 are 2
The link 12 is supported by a number of pins (a) 17.
Drive is transmitted through pin (b) 18 of. link 12
is operated by the electromagnetic solenoid 13 using the pin (c) 19 as a fulcrum.

Further, when the electromagnetic solenoid 13 is not working, the link 12 is always pulled by a tension coil spring 20 to maintain the paper guide L10 and paper guide R11 apart from the platen 3 via the fulcrum 19.

Next, the operation of the printer according to the embodiment of the present invention will be explained with reference to FIG.

When the P/H 7 is located on the left side as shown in FIG. 3(a), the electromagnetic solenoid B' is not driven as shown in FIG. 2, and the paper guide is moved through the fulcrum 19' by the action of the coil spring 20'. 10 is released from the platen. However, P
The paper is restrained by the card holder 2 on the left side around /H7. At this time, on the right side, the electromagnetic solenoid 13
is energized and the electromagnetic solenoid 13 is driven in the direction of the arrow in FIG.

When the P/H 7 is located at the center as shown in FIG. 3(b), both the electromagnetic solenoids 13 and 13' are energized and actuated in the direction of the arrow in FIG. Through the links 12 and 12', both the paper guide L10 and the paper guide R11 are pressed in the direction of the platen 3 to restrain the paper.

As shown in FIG. 3(c), when the P/H7 is located on the right side, the paper guide L10 is moved by the electromagnetic solenoid 13.
′, fulcrum 19′, and link 12′, the platen 3
The left side of the paper is restrained, but the paper guide R1
1 is a coil spring 20', a fulcrum 19', a link 1
2' separates from the platen 3 and does not restrain the right side of the paper. At this time, the right side of the paper is restrained by the card holder 2.

[0018]

Effects of the Invention As is clear from the above explanation, the printer of the present invention can further narrow the printing range without increasing the external dimensions of the printer by changing the position of the paper guide due to the P/H movement. This has the effect of eliminating bulges in the printing medium and preventing paper jams.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a printing mechanism including a paper jam prevention mechanism according to an embodiment of the printer of the present invention.

FIG. 2 is an enlarged side view of essential parts showing the configuration and operation of the paper jam prevention mechanism according to the embodiment of the present invention.

FIG. 3 is a schematic diagram showing the operation of the paper jam prevention mechanism section of the printer embodiment of the present invention.

FIG. 4 is a perspective view showing a printing mechanism section of a conventional printer.

[Explanation of symbols]

1 Printing media paper 3 Platen 7 Print head (P/H) 13 Electromagnetic solenoid 14 Sensor board 15 Optical sensor L 16 Optical sensor R 20 Tension spring

Claims (3)

[Claims] 1. A printer having a dot serial type print head, wherein a plurality of plate-shaped paper guides each capable of individually restraining and releasing a print medium paper between the platen and the platen, and the plate-shaped paper guide are attached to the platen. an electromagnetic solenoid for pressing, a spring for separating the plate-shaped paper guide from the platen, and a link for transmitting the drive of the electromagnetic solenoid and the spring to each of the plate-shaped paper guides via a fulcrum. A printer characterized in that it has a jam prevention mechanism. 2. When the print head is located on the left side of the printer, the spring drives the link via the fulcrum to separate it from the left side paper guide and platen, and restrains the left side paper with the card holder; 2. The printer according to claim 1, wherein the right side part has a jam prevention mechanism for restraining the right side paper so as to drive the electromagnetic solenoid and press the right side paper guide against the platen. 3. When the print head is on the right side, the link is driven by the spring, the right side paper guide is separated from the platen, the right side paper is restrained by the card holder, and the left side is driven by the electromagnetic solenoid. 2. The printer according to claim 1, further comprising a jam prevention mechanism for restraining the left side paper so as to drive the left side paper guide and press the left side paper guide against the platen.