JPS6112563A - Printer - Google Patents

Abstract

PURPOSE:To aim at accurate paper end detection for recording paper going to both forward and backward direction, by installing a detection lever which turns round frontward with its own weight by passage of a recording paper end comes into contact with a switch, outputting a paper end signal, as well as being regulated for its rotation to the rearward. CONSTITUTION:In time of forward movement of recording paper 27, is smoothly proceeds in and around a detection lever 22 which touches the recording paper 27 with its own weight, and since it receives pressing force of a plate spring 23, if an end of the recording paper 27 passes through a position of the lever 22, the latter turns round to the front side of a printer with its own weight, entering the inside of a slipt 24 and pushing a switch 25 via a pressing plate 26, and this switch 25 outputs a paper end signal, while the printer 1 notifies that the recording paper 27 is used up by means of a lamp or the like. And, in time of backward movement of the recording paper 27, the recording paper 27 makes the lever 22 so as to turn round to the rearward of the printer 1, but if the lever 22 tries to turn round more than the specified angle, it is held between an incline 20 of a support body 15 and the plate spring 23, thus its rotation is regulated. Therefore, the end of the recording paper 27 is accurately detectable even in time of backward movement.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a printer, and more particularly to a printer equipped with a paper end detection mechanism that detects the end of recording paper.

(Prior Art) Printers usually use cut paper or continuous paper, and when continuous paper is used, the end of the recording paper is detected by a paper end detection mechanism. Conventionally, this vapor end detection mechanism has, for example, disposed a light emitting element and a light receiving element facing each other near a platen, and passing a recording paper between the light emitting element and the light receiving element so as to prevent the recording paper from being exposed. There is one that detects 1 in α. As a second example, a light-emitting element that emits light toward a platen on which recording paper is wound, and a light-receiving element that receives light reflected from this light-emitting element from the recording paper are provided to detect the end of the recording paper. As a third example, two guide plates are arranged in parallel with a predetermined distance apart in front of the platen, and slits are formed in opposite positions of both guide plates, so that one guide plate can be detected. A lever that can protrude from the slit of the other guide plate is attached to the slit of the other guide plate, and when the recording paper passes between both guide plates and is fed to the platen, the lever is pushed by the recording paper and moves one of the guide plates. When a switch attached to the side is pressed and the end of the recording paper passes the lever position, the lever projects into the slit and leaves the switch, detecting the end of the recording paper.

However, printers equipped with such conventional paper end detection mechanisms have problems such as poor assembly, high cost, low reliability, and buckling of the recording paper. That is, in the first and second examples, the light-emitting element and the light-receiving element must be placed near the platen where components are highly concentrated, resulting in poor assembly efficiency and high cost. Furthermore, small paper scraps from the recording paper adhere to the element, deteriorating the reliability of the paper end detection mechanism. Furthermore, in the third example, when using cut paper, the lever acts as resistance when feeding the paper between the guide plates, causing the paper to buckle. In order to prevent this paper from buckling, when using cut paper, it is necessary to add a mechanism to move the lever so that it does not protrude between the guide plates, which makes the mechanism complicated and The cost will be high.

(Purpose) Therefore, the present invention provides a printer that accurately detects the end of the recording paper even when the recording paper moves forward and backward, and is equipped with a simple and inexpensive paper end detection mechanism. is intended to provide.

(Structure) In order to achieve the above object, the present invention provides a printer equipped with a paper end detection mechanism that moves recording paper forward and backward for recording and detects the end of the recording paper. a support that is attached to the rear of the upper surface of the printer casing, one side of which protrudes in a substantially step-like manner toward the rear of the printer, and the stepped portion is formed of an inclined surface; The detection lever is rotatably supported and rotates toward the front of the printer under its own weight and comes into contact with the recording paper.When the end of the recording paper passes the detection lever position, the detection lever rotates toward the front of the printer under its own weight. When the switch that moves and comes into contact and outputs a paper end signal and the detection lever rotate toward the rear of the printer by more than a predetermined angle, the output lever is pressed against the inclined surface of the support to prevent the rotation of the detection lever. It is characterized by having a biasing means for regulating.

Hereinafter, the configuration of the present invention will be specifically explained based on examples.

1 to 7 are diagrams showing a first embodiment of the present invention. First, to explain the configuration, in FIG. 1, a tractor feeder 2 for continuous paper feeding is attached to a printer 1, and the tractor feeder 2 has a side plate 4. 5, a guide rail 6.7 passed between side plays 1 and 4.5, a tractor 8 attached to the guide rail 6.7 so as to be movable along the guide rail 6.7, and a recording paper. It has a paper guide 9.10 for guiding the paper. The tractor 8 is driven by the rotation of the guide rail 6, and moves the recording paper set between it and the trough cover 11, 12 forward and backward.

A paper end detection mechanism 13 is attached to the rear end of the top surface of the housing 3 of the printer 1, and the paper end detection mechanism 13 is configured as shown in FIG.

That is, a support body 14.15 is fixed to the rear end of the upper surface of the housing 3, and through holes 16.17 are formed at corresponding positions in two parts of the support body 14.15. The upper part of one side (outer side) of one support 15 is the printer 1
It has a lower step part 18 and an upper step part 19 that protrude in a substantially step-like manner on the rear side, and the step part is formed by an inclined surface 20. Further, the lower side surface 21 of the one side surface further protrudes laterally from the two-step portion 19 by a predetermined length e. Both ends of the detection lever 22 are loosely inserted into the through hole 16.17 of the support 14.15, and the detection lever 22 is inserted into the through hole 16.17 of the support 14.15.
15 so as to be rotatable. In addition, the detection lever 2
2 has its center part protruding toward the front side of the printer 1,
The diameter R of the detection lever 22 is the upper part 19 of the lower side surface 21.
It is larger than the protrusion length l from. A plate spring (biasing means) 23 is further attached to the support body 15 so as to sandwich the support body 15 from below, and the plate spring 23 protrudes upward from the lower side surface 21 to at least touch the −h step portion 19. and covers the inclined surface 20. An elastic force acts on the leaf spring 23 in a direction to clamp the support body 5.

Note that the plate spring 23 is attached to the support body 15 by a bolt (not shown).
is fixed. The support bodies 14, 15, the detection lever 22, and the leaf spring 23 collectively constitute the paper end detection mechanism 13, which, as explained above, has a very simple structure.

In addition, in FIG. 1, a slit 24 is formed in the housing 3 of the printer 1, through which the detection lever 22 can enter when the detection lever 22 rotates toward the front side of the printer 1. A switch 25 (see FIGS. 4 and 6) is provided that is pressed by the detection lever 22 to output a paper end signal when the detection lever 22 enters the housing 3 through the slit 24. Note that a pressing plate 26 is provided above the switch 25 in order to ensure that the detection lever 22 turns on the switch 25 .

Next, the effect will be explained.

When printing, a recording paper 27 is set in the printer 1 by passing it under the detection lever 22, as shown in FIG. At this time, as schematically shown in FIG. 4, the detection lever 22 is in contact with the recording paper 27 in a state in which it has rotated slightly toward the front of the printer 1 due to its own weight rather than in the vertical state, and the switch 5 is pressed. It has not been. Therefore, switch 25
does not output the paper end signal.

The recording paper 27 is fed by the tractor 80 rotations, but when the recording paper 27 is fed in the direction of the arrow in FIG. is in contact with the recording paper 27 in a state where it is tilted slightly toward the front side of the printer 1 due to its own weight. At this time, the detection lever 22 is moved by the leaf spring 23 as shown in FIG.
It is not under the pressure of Therefore, as shown in FIG. 6, when the end of the recording paper 27 passes the position of the detection lever 22, the detection lever 22 rotates toward the front side of the printer 1 by its own weight and enters the slit U, and the pressing plate 26 Press the switch 25 via the button. The switch 5 outputs a paper end signal, and the printer 1 uses a lamp or the like to notify that the recording paper 27 is out.

On the other hand, when the recording paper 27 is fed in the reverse direction of the arrow in FIG. 4, the recording paper 27 attempts to rotate the detection lever 22 toward the rear of the printer 1. However, when the detection lever 22 attempts to rotate toward the rear of the printer 1 by more than a predetermined angle (more than an angle slightly tilted toward the front of the printer 1 from the vertical position), the detection lever 22 is rotated so that its diameter R extends beyond the protrusion of the lower side surface 21. length! Since it is larger, as shown in FIG. 7, it is sandwiched between the inclined surface 20 of the support body 15 and the leaf spring 23, and rotation of the printer 1 toward the rear side is restricted.

Therefore, even when the recording paper 27 moves backward, the detection lever 22 can be maintained in a slightly rotated state toward the front of the printer 1. As a result, when the end of the recording paper 27 passes the detection lever 22 position, the detection lever 22
2 securely rotates toward the front side of the printer 1 to open the slit 22.
and presses the switch 25 via the press Fj, 26. Therefore, even when the recording paper 27 moves backward, the end of the recording [27] can be reliably detected by the paper end detection mechanism 13, which has a very simple configuration.

In addition, when using cut paper for printer 1,
The paper end detection mechanism 13 is no longer necessary, and the tractor feeder 2 is removed and an O-1 sheet feeder (automatic paper feeder) for cut paper is installed, but in this case,
Since the detection lever 22 is only pressed against the inclined surface 20 by the plate spring 23 and its rotation is restricted, the detection lever 22 is forcibly rotated toward the rear of the printer 1 so that it does not touch the top surface of the printer 1. The detection lever 22 can be positioned parallel to the printer 1 or below the top surface of the printer 1, so that the detection lever 22 does not become an obstacle to attaching an automatic sheet feeder or the like.

FIG. 8 is a diagram showing a second embodiment of the present invention. In explaining this embodiment, the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

In FIG. 8, an arm 31 shaped like a single character is fixed to the detection lever 22, and the arm 31 is fixed to the printer casing (not shown) when the detection lever 22 is rotated toward the front side of the printer. A hole is formed into which the tip can enter. A switch 25 (see FIGS. 4 and 6) that is pressed by the tip of the arm 31 is further attached to the housing at the position where this hole is formed. Further, a cover 32 is attached to cover the support body 15 and the leaf spring 23, and the cover 32 prevents the leaf spring 23 from being bent in a direction opposite to the support body 15 beyond its elastic limit. Support 1
4.15, detection lever 22, arm 31, leaf spring 23,
The switch 25 and the cover 32 constitute a paper end detection mechanism 33.

Therefore, in this embodiment, when the recording paper is forwarded and reversed for recording, the end of the recording paper can be reliably detected with a simple configuration, and the printer can It is only necessary to form a small hole in the casing through which the arm 31 penetrates, and it is possible to prevent the paper end detection mechanism 33 from being damaged due to bending of the leaf spring 23 beyond its elastic limit.

FIG. 9 is a diagram showing a third embodiment of the present invention. In explaining this embodiment, the same components as those in the first embodiment are given the same reference numerals, and the explanation thereof will be omitted.

In FIG. 9, a biasing plate 41 that covers the upper part 9 and the inclined surface 20 (see FIG. 2) is rotatably attached to the support 15. It is covered with a cover 42 fixed to 15. Biasing plate 4
1 is a coil spring 4 compressed between the cover 42 and
3 toward the support body 15, and a spacer 44 is interposed between the bias @41 and the support body 15.

The distance 12 between the upper stage portion 19 and the biasing plate 41 when the biasing plate 41 is in contact with the spacer 44 is formed to be somewhat smaller than the diameter R of the detection lever 22 . Support body 15 and support body 14 (see Fig. 2), detection lever 22, switch 25 (see Fig. 4.6).
(See figure) Biasing plate 41, cover 42, coil spring 4
3 and spacer 44 are paper end exclusive mechanism 45
The biasing plate 41, cover 42, and coil spring 43 constitute biasing means 46.

Therefore, in this embodiment, when the detection lever 22 attempts to rotate toward the rear of the printer by a predetermined angle or more, the detection lever 22 is pressed against the inclined surface by the biasing plate 41 biased by the coil spring 43, and the detection lever 22 22 is restricted from rotating to the rear of the printer beyond a predetermined angle. As a result, the end of the recording paper can be reliably detected with a simple configuration.

(Effects) According to the present invention, the end of the recording paper can be reliably detected with a very simple configuration even when recording is performed by moving the recording paper forward and backward.

Furthermore, in the second embodiment, it is only necessary to form a small hole in the printer housing into which the arm can enter, and it is possible to prevent the leaf spring from being bent beyond its elastic limit and damaged.

[Brief explanation of drawings]

1 to 7 are diagrams showing a first embodiment of the present invention, in which FIG. 1 is a perspective view of the entire structure, FIG. 2 is a perspective view of its paper end detection mechanism, and FIG. 3 is a perspective view of its paper end detection mechanism. 4 is a schematic diagram showing the operation when the recording paper is set, and Figure 5 is an explanation of the operation of the paper end detection mechanism when the recording paper is set. 6 is a schematic diagram showing the operation when the end of the recording paper passes the paper end detection mechanism, and FIG. 7 is an explanatory diagram of the operation of the paper end detection mechanism when the recording paper is reversed. FIG. 8 is a perspective view of a paper end detection mechanism according to a second embodiment of the present invention, and FIG. 9 is an enlarged front view of essential parts of a paper end detection mechanism according to a third embodiment of the present invention. 1-------Printer, 3...-1--Housing, 13.33.45--Paper end detection mechanism, 14.15--1 Support, 20-- ---m slopes, 22 --- one detection lever, 23.46.--111 biasing means, 25 --- switch, 27 --- recording paper.

Claims (3)

[Claims] (1) In a printer equipped with a paper end detection mechanism that records by moving the recording paper forward and backward and detecting the end of the recording paper, the paper end detection mechanism is attached to the upper rear part of the printer housing, A support body whose one side protrudes in a substantially step-like manner at the rear side of the printer and whose step part is formed of an inclined surface, and which is rotatably supported by the support body along the one side surface of the support body, and whose own weight A detection lever that rotates toward the front of the printer and touches the recording paper,
When the end of the recording paper passes the detection lever position, the detection lever rotates toward the front of the printer under its own weight and comes into contact with a switch that outputs a paper end signal, and the detection lever rotates toward the rear of the printer by more than a predetermined angle. A printer characterized in that the printer comprises a biasing means for pressing the detection lever against the inclined surface of the support to restrict rotation of the detection lever. (2) The printer according to claim 1, wherein the biasing means is constituted by a plate spring. (3) The biasing means is comprised of a biasing plate that presses the detection lever and a spring that biases the biasing plate toward one side of the support. The printer described in scope 1.