JPH09295745A - Paper terminal detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect a paper terminal and to improve reliability by providing a detecting device, a detecting lever arranged in a predetermined interval from the detecting device and having a projection part which can contact a side surface of roll-like recording paper, and a detection switch for converting an operation of the detection lever into an electric signal. SOLUTION: In the case of recording paper having a medium size diameter, a detecting device 64 is separated from the side of the recording paper S but a projection part 65 contacts the side surface of the recording paper when the outside circumference of the recording paper moves to a position where the paper contacts a support part which is formed in an acute angle. Furthermore, even in the case where the recording paper S is swung, either the detecting device 64 or the projection part 65 contacts a side surface of the recording paper and the detecting lever is not rotated and a limit switch is kept in an off-state. Then when the residual amount of the recording paper is few, the detecting device enters into a space of a winding core 75 so that the limit switch is turned on thereby detecting a terminal of the recording paper. Thus, reliability in the detection of the residual amount of the recording paper S is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper end detection device for detecting the vicinity of the end of a roll of recording paper supplied to a printer or the like.

[0002]

2. Description of the Related Art Conventionally, this type of technology is disclosed in, for example, Jitsuko Sho6.
As shown in JP-A 1-3872 and JP-B 1-14597, when the remaining amount of the recording paper is below a certain amount, the detector urging the side surface of the roll-shaped recording paper is It is known that the detection switch is actuated when the recording paper enters the space of the core of the recording paper to detect that the remaining amount of the recording paper is very small.

[0003]

However, in the above-mentioned prior art, the roll-shaped recording paper is swung by the paper feeding of the printer or moved to the printer main body side having the paper feeding means, and a desired detector is provided. It may move away from the detection position. In this case, the detection lever equipped with the detector rotates to actuate the detection switch in the same manner as when the detector enters the space of the core because the detector is disengaged from the side surface of the roll-shaped recording paper. . Therefore, the conventional paper end detector operates the paper end detection device even though there is printable recording paper, so the remaining amount of recording paper cannot be accurately detected and the recording paper is wasted. It was unreliable.

The present invention has been made in consideration of the above problems of the prior art, and an object of the present invention is to improve the reliability capable of accurately detecting the end of the roll-shaped recording paper. Another object of the present invention is to provide a paper end detection device.

[0005]

In order to achieve the above-mentioned object, a paper end detection device of the present application converts an operation of a detector into a space of a core portion of a roll-shaped recording paper into an electric signal to convert the operation. In a paper end detecting device for detecting that the remaining amount of the paper is below a certain amount, it is provided with a detector and a protrusion that is arranged at a predetermined interval from the detector and can contact the side surface of the roll-shaped recording paper. And a detection switch that changes the operation of the detection lever into an electric signal.

Further, the tip of the detector and the tip of the protrusion are characterized in that they are on substantially the same plane of the side surface when the detector is in contact with the side surface.

According to the above construction, since the detection lever has the detector and the protrusion disposed at a predetermined distance from the detector, even when the recording paper is swung, the detector is separated from the side surface. Since the protrusion contacts the side surface of the roll-shaped recording paper, the detection lever does not operate the detection switch.

When the detector is in contact with the side surface,
Since the tip of the detector and the tip of the protrusion are on substantially the same plane on the side surface, when the detector is disengaged from the side and the protrusion contacts, the detection lever hardly moves.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a paper end detecting device according to the present invention will be described in detail below with reference to FIGS.

FIG. 1 is an external view of the left side surface of a printer equipped with the present invention with a cover frame 10 opened. This printer is applied to, for example, a receipt printer used in a POS system or the like,
For example, recording such as printing is performed by a heat sensitive print head 39 (see FIG. 2) on a roll-shaped recording paper S, which is one of the recording media. And a roll paper storage unit for storing and holding the recording paper S.

The printer includes an autocutter unit 1 for accommodating an openable / closable cover frame 10 provided on a roll paper accommodating portion, a movable blade 32 and a driving means thereof.
One.

The cover frame 10 is attached so as to be swingable, that is, openable and closable around a support shaft 14 provided at both upper ends of a main body frame 13 made of metal or the like. The cover frame 10 is provided with an arc-shaped lid portion 15 for avoiding contact with the recording paper S when the cover frame 10 is closed, a platen 18, and a fixed blade 33.

Inside the cover frame 10 which is opened, a roll paper holder 17 made of resin is arranged. Further, on the left side surface of the main body frame 13, a paper end detector 24 for detecting that the remaining amount of the recording paper S has become small.
Is attached.

FIG. 2 is a side sectional view of the printer with the cover frame 13 closed, showing a roll paper holder 17
The recording paper S is held and is being fed. FIG. 2 shows a state in which a large-diameter recording paper S having a large outer diameter in the initial stage of use is stored, and the paper is fed,
As the outer diameter of the recording paper S becomes smaller, the recording paper S falls into the guide portion 38. Then, the paper end detector 24 described above detects that the outer diameter of the recording paper S has become smaller.

The recording paper rewound from the roll-shaped recording paper S is sandwiched between the platen 18 and the print head 39, and when the platen 18 rotates, the paper is fed by the frictional force.

The recording paper S passing through the print head 39 passes between the movable blade 32 and the fixed blade 33, is discharged in the direction of the arrow D, and drives the movable blade 32 to the fixed blade 33 side to cut at a desired position.

The outline of the overall basic configuration of the printer 1 according to the present embodiment has been described above. Next, the paper end detector 24, which is a feature of the present invention, will be described with reference to FIGS.
Will be described in more detail.

3 and 4 show the paper end detector 24 in this embodiment. FIG. 3 is a front view and FIG. 4 is a side view.

The paper end detector 24 of the present embodiment is generally composed of a detection frame 62 and a detection lever 63, both of which are long members. Both the detection frame 62 and the detection lever 63 are made of acrylonitrile-butadiene-
Styrene copolymer (ABS), polyacetal (PO
It is made of a resin material such as M). Two support shafts 63a and 63b are symmetrically provided at the base end of the detection lever 63,
As shown in FIG. 4, the detection lever 63 is rotatably locked to the detection frame 62 about these support shafts 63a and 63b.

At the tip of the detection lever 63, a detector 64 that comes into contact with the side surface of the recording paper S is provided. The detector 64 is made of, for example, a resin material, but the detection lever 63
It may be formed integrally with the. Also, the detector 6
4 is formed so as to extend in a direction orthogonal to the longitudinal direction of the detection lever 63. The detector 64 is, as described later,
The recording paper S is formed in a tapered shape so as to easily enter the space 76 of the winding core 75.

As shown in FIG. 4, the detection lever 63
A protrusion 65, which will be described later, is provided in the central portion of the. The protrusion 65 is made of, for example, a resin plate member, and is formed to extend in a direction orthogonal to the longitudinal direction of the detection lever 63, like the detector 64. in this case,
The length of the protrusion 65 is formed to be slightly shorter than the length of the detector 64. The protrusion 65 may be formed integrally with the detection lever 63.

Further, an inclined surface 65a is formed on the side of the protrusion 65 facing the detector 64, that is, on the outer side in the radial direction of the recording paper S, and the tip of the protrusion 65 is tapered. There is.

On the other hand, as shown in FIG.
2, a window portion 62a for letting the protrusion 65 of the detection lever 63 escape is formed. In addition, a support portion 66 is formed substantially at the center of the detection frame 62.
A limit switch 67 is provided above. And
By rotating the detection lever 63, the limit switch 6
7 is configured to turn on and off. In the present embodiment, the detection lever 63 is pressed against the detection frame 62 by the pressing force of the switch pin 68 by the spring in the limit switch 67. The limit switch 67 is connected to a main circuit board (not shown) that controls the printer by FFC or the like.

FIG. 5 shows the operation of the paper end detector 24 in the present embodiment. FIG. 5 (a) shows the case where the paper end detector 24 is off and FIG. 5 (b) shows the paper end. Detector 2
4 indicates an ON state.

As shown in FIG. 5A, when the remaining amount of the recording paper S is large, the detector 64 or the protrusion 65 of the detection lever 63 abuts against the side surface of the recording paper S, so that the detection lever 63 moves. It is pushed back and the limit switch 67 is kept in the off state.

By the way, in the case of the thermal printer as in the present embodiment, the recording paper S is not conveyed intermittently as in the dot printer, so that the recording paper S slackened by rewinding has a roll-shaped recording paper S and a width. If there is a deviation in the direction, there is a problem that it cannot be corrected.

In order to prevent this, the roll paper holder 17 is provided with a guide portion 38 so as to swing the recording paper S to some extent.
A support surface 17c having a sloping slope is arranged on the paper feed side. As a result, when the platen 18 rotates and the recording paper is conveyed, the roll-shaped recording paper S rides on the support surface 17c, and the recording paper S is formed by the support surface 17a formed at a steep angle.
Is rewound to the guide portion 38. When the outer diameter of the recording paper S is large as described above, the recording paper S is unwound and rewound intermittently. When the recording paper S has a small diameter, it becomes difficult to remove it from the guide portion 38, but even if the recording paper S is displaced in the width direction, the weight is also light and can be easily corrected.

When the recording paper S has a medium diameter, when the outer circumference of the recording paper S moves to a position where it comes into contact with the support portion 17a formed at a steep angle, the detector 64 of the detection lever 63 causes the recording paper S to move.
As shown in FIG. 5A, according to the present embodiment, even if the recording paper S is swung, any of the detector 64 of the detection lever 63 or the protrusion 65 is disengaged from the side surface of the recording paper S. Since one side hits the side surface of the recording paper S, the detection lever 63
Does not rotate and the limit switch 67 is kept in the off state.

Then, as shown in FIG. 5B, when the remaining amount of the recording paper S becomes very small, the recording paper S moves and the detector 64 of the detection lever 63 causes the core 64 to move. The limit switch 67 is turned off because it enters into the space 76, and a signal to that effect is sent to the above-mentioned main circuit board. As a result, the paper end state of the recording paper S is detected.

As described above, since the detection lever 63 is provided with the protrusion 65 facing the recording paper S, the paper end detector 24 is always provided even when the recording paper S is swung. Since it is kept in the off state, it is possible to prevent malfunction of detection of the paper end, and the effect of the present application is not limited to the case where the paper is continuously fed or the shape of the storage section.

For example, when the recording paper is intermittently conveyed in a short time like a dot impact printer, when the roll-shaped recording paper is used and the outer diameter becomes small, the paper is not rewound instantaneously. However, even in this case, even if the detector 64 is separated from the side surface, the detection lever 63 does not move as long as the side surface of the protrusion 65 is in contact with the detector 64. Can be accurately detected.

The length of the protrusion 65 is formed to be slightly shorter than the length of the detector 64 as described above. However, the length of the protrusion 65 when the detector 64 is in contact with the side surface is small.
The front end portion 64a and the front end portion 65b of the protruding portion 65 are arranged on substantially the same plane of the side surfaces and are brought into contact with each other at the same time. With this configuration, when the detector 64 comes off from the side surface and the protrusion 65 contacts, the detection lever 63 hardly moves, so that the detection accuracy is improved.

Further, if the inclined surface 65a is provided below the detector 64 and the protrusion 65, when the recording paper S is exchanged, the detector 64 of the detection lever 63 is inserted into the space 76 to form the core portion 75. Is lifted upward, the detector 64 is taken out of the space 76 by the inclined surface, so that the winding core 75 can be easily removed from the recording paper storage unit. Also, the protrusion 6
If an inclined surface is provided below 5 as well, even if the core portion 75 hits the protrusion portion 65 when the core portion 75 is removed, the slope portion moves the protrusion portion 65 to the outside, so that the core portion is engaged by the protrusion portion. It is not stopped and the handleability is further improved.

In the present embodiment, the core of the roll-shaped recording paper used in ECR or electronic desk calculator has an outer diameter of 18 mm.
mm, inner diameter 12 mm, or outer diameter 22 mm, inner diameter 12 mm
The predetermined distance and shape are determined so that the two types can be detected. However, the present invention is not limited to this, and when a special winding core is used, it may be formed according to the winding core.

Further, the paper end detecting means is not limited to the one using the limit switch, and for example, a means for detecting the paper end of the recording paper by an optical means may be used. However, if the one using the limit switch is used as in the present embodiment, there is an advantage that the end of the paper can be detected easily and surely.

[0036]

As described above, according to the first aspect of the invention, even when the roll-shaped recording paper is moved from the detection position, either the detector of the detection lever or the protrusion is The side of the recording paper is touched and the detection lever does not move to activate the detection switch. As a result, the reliability of the detection, which is performed only when the remaining amount of the recording paper becomes a certain amount or less, is greatly improved.

Further, in the case of the second aspect of the present invention, even if the detector is separated from the side surface, the detection lever hardly moves as long as the side surface is in contact with the protruding portion. Can be accurately detected.

[Brief description of drawings]

FIG. 1 is a perspective view of a printer equipped with the present invention, showing a state in which a cover frame is opened.

FIG. 2 is a side sectional view of a printer in which the cover frame of the printer equipped with the present invention is closed.

FIG. 3 is a front view showing a paper end detector in the same embodiment.

FIG. 4 is a side view showing a paper end detector in the same embodiment.

5A and 5B are explanatory views showing the operation of the paper end detector in the same embodiment, FIG. 5A is a state in which the paper end detector is off, and FIG. 5B is a state in which the paper end detector is on. Shows the state of.

[Explanation of symbols]

 13 body frame 17 roll paper holder 24 paper end detector 32a, 32b hole 38 guide part 62 detection frame 63 detection lever 64 detector 65 protrusion 67 limit switch 75 core part 76 space S recording paper

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Nakajima 3-5 Yamato, Suwa City, Nagano Seiko Epson Corporation (72) Inventor Yoshiharu Matsumoto 3-5 Yamato, Suwa City, Nagano Prefecture Seiko Epson Within the corporation

Claims (2)

[Claims] 1. A paper end detecting device for converting an operation of a detector into a space of a core portion of a roll-shaped recording paper into an electric signal to detect that the remaining amount of the recording paper is below a certain amount. In the above, the detection lever and a detection lever provided at a predetermined distance from the detection element and provided with a protrusion capable of contacting the side surface of the roll-shaped recording paper, and the operation of the detection lever are changed into an electric signal. A paper end detecting device having a detection switch for 2. The tip of the detector and the tip of the protrusion are on substantially the same plane of the side surface when the detector is in contact with the side surface. The paper end detection device described.