JPH0818452B2 - Printer print medium detection mechanism - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print medium detection mechanism in a printer.

[Conventional technology]

For example, a printer having two paper traveling paths such as a tractor unit for feeding a printing paper having a sprocket hole and a paper traveling path by a platen and a paper traveling path by a platen and a paper guide for a cut sheet is well known. The conventional technique will be described below with reference to FIG.

The drawing is a side view of the main part, and in the drawing, 1 is a platen, and a detection groove 1a is formed in the circumferential portion outside the printing area.

2 is a print head, 3 is print paper, 4 is this print paper 3
A paper chute for guiding the sheet, 5 is a tractor unit for feeding the print sheet, 6 is the other print sheet, 7
Is a paper chute for guiding the printing paper 6,
Two types of printing paper 3, including the above paper chute 4,
6 forms the paper path.

Reference numeral 8 denotes a bent first print detection lever, the bending point of which is rotatably supported by a support bracket 10 via a rotation fulcrum 9, and the tip of the head 8a is loosely fitted in the detection groove 1a of the platen 1. And the rear part 8b is a medium detection sensor.
It is placed so as to abut 11. 8c is a protrusion.

Reference numeral 12 is a bent second print detection lever, and the bending point thereof is rotatably supported by the support bracket 10 via a rotation fulcrum 13. The head 12a of the second print detection lever 12
Is arranged so as to abut the paper chute 7, and the rear portion 12b is arranged so as to abut the projection 8c.

According to the above configuration, when the printing paper 3 is sent from the direction A of the arrow through the paper chute 4 to the platen 1 by the tractor unit 5, the printing paper 3 pushes the head 8a of the first print detection lever 8 downward. Lower to. As a result, the rear portion 8b goes up, and the medium detection sensor 11 has the print sheet. At this time, the second print detection lever 12 is in contact with the paper chute 7.

Next, when the printing paper 6 is sent out from the arrow direction B to the platen 1 via the paper chute 7 by the tracker unit 5, the printing paper 6 pushes out the head portion 12a of the second print detection lever 12, and thereby the rear portion 12b. Presses the protrusion 8c of the first print detection lever 8 and raises the rear portion 8b upward, and the medium detection sensor 11 detects the presence of print paper.

[Problems to be Solved by the Invention]

However, recently, with the diversification of printing paper, three types of printing paper, such as friction feed for single-cut paper, tractor feed by push tractor for printing paper with sprocket holes, and bottom tractor feed by pull tractor, are now available. In some cases, it is not possible to detect three types of printing paper by the same detection mechanism in the above-mentioned conventional technique.

[Means for solving the problem]

According to the present invention, the paper chute is provided on the platen in three directions, and the paper chute from the three directions is rotated in one direction by the paper sheet entering the paper chute in one direction. A cam is arranged, and a second detection cam that rotates in both directions is arranged between the remaining two paper chutes depending on whether one of the paper chutes has entered the printing paper. One pendulum that interlocks with the rotation due to the entry of the sheet is provided, and the pendulum receives the transmission of the rotation of the first cam against the bidirectional rotation of the second detection cam against its own weight. An oscillating body that transmits rotation to the pendulum so that the pendulum swings in the same direction as that of the pendulum. In the same direction The detection sensor to the sensor lever, characterized in that placed opposite.

[Action]

According to the above configuration, when the printing paper is fed into each paper chute, the sensor lever operates via the detection cam, and the operation allows the detection sensor to detect the presence of the printing paper. One of the paper chutes can detect that the printing paper has been fed into one of the paper chutes by one detection sensor.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a detection mechanism, FIG. 2 is a side view of a main part showing a case of friction feed, FIG. 3 is a side view of a main part showing a case of tractor feed, and FIG. 4 is a side view of a bottom tractor feed. FIG. 4 is a side view of a main part shown, in which the same parts as those in the above-described conventional technique are designated by the same reference numerals, and description thereof will be omitted.

In the figure, reference numeral 1 is a platen, and a detection groove 1a is formed in the circumferential portion outside the printing area. 2 is a print head.

14 is the first used in the case of friction feed, for example.
Is a second paper chute used for tractor feed, and 16 is a third paper chute used for bottom tractor feed, for example.

 Reference numeral 17 indicates a push tractor, and 18 indicates a pull tractor.

The tip of 19 can appear and disappear in the first paper chute,
The detection cam is arranged so as to be loosely fitted in the detection groove 1a of the platen 1, and is connected to the actuator 21 via the shaft 20.

Reference numeral 22 denotes a pendulum, and a sensor lever 24 is connected to the pendulum 22 in a crank shape via a shaft 23 provided above the shaft center of the shaft 20.
It works with 21.

A detection sensor 26 is arranged opposite to the sensor lever 24, and the detection sensor 26 is detected depending on whether the sensor lever 24 faces or not.
26 is turned off and on.

Reference numeral 27 denotes a detection cam, which is attached to one end of a shaft 28 so that the periphery of the detection cam can be retracted into the second and third paper chutes 15 and 16.

An oscillating body 29 is attached to the other end of the shaft 28, and a front portion 29a and a rear portion 29b of the oscillating body 29 can be brought into contact with the side surfaces of the pendulum 22 so as to face each other.

Here, the front part 29a and the rear part 29b of the oscillating body 29 are the pendulum 22
However, even if the detection cam 27 rotates in either direction around the shaft 28 as a fulcrum, the pendulum 22 is pushed against the oscillating body 29. It is designed to rotate in one direction.

With the above construction, as shown in FIG. 2, when a single-cut sheet is fed from the first paper chute 14, the single-sided sheet advances along the platen 1 and the detection cam 19 moves in the direction of arrow a in FIG. Rotate. As a result, the actuator 21 is rotated in the direction of the arrow b, and this rotation is caused via the protrusion 25.
22 is rotated in the direction of arrow c, and as a result, the sensor lever 24 is rotated in the direction of arrow d to remove the facing of the detection sensor 26 and detect the presence of paper.

When the cut sheet is used up, the turning force from the actuator 21 disappears, and the pendulum 22 rotates in the direction opposite to the arrow c by its own weight and returns.
As a result, the detection cam 19 also rotates in the direction opposite to the arrow a and returns, and the sensor lever 24 also rotates in the direction opposite to the arrow d and returns.
It faces the detection sensor 26 and detects the absence of paper.

Next, as shown in FIG. 3, for example, a push tractor
When the printing paper is fed from the second paper chute 15 by the 17, the printing paper is pushed by the detection cam as shown in FIG.
27 rotates in the direction of arrow e. As a result, the oscillating body 29 also rotates in the direction of arrow f, and the rear portion 29b pushes the lower portion of the pendulum 22 to rotate in the direction of arrow c. As a result, the sensor lever 24 is rotated in the direction of the arrow d so that the sensor lever 24 is not opposed to the detection sensor 26 and the presence of paper is detected.

When the printing paper runs out, the detection cam 27 returns in the direction opposite to the arrow e, and the swinging member 29 also rotates in the direction opposite to the arrow f,
The pendulum 22 having no pressing force returns by rotating in the direction opposite to the arrow c by its own weight. As a result, the sensor lever 24 also rotates in the direction opposite to the arrow d and returns, and faces the detection sensor 26 to detect the absence of paper.

Next, as shown in FIG. 4, when the printing paper is fed from the third paper chute 16 by, for example, the pull tractor 18, as shown in FIG.
Rotates in the direction of arrow g. As a result, the oscillating body 29 also rotates in the direction of arrow h, and the front portion 29a pushes the pendulum 22 to rotate in the direction of arrow c. As a result, the sensor lever 24 is rotated in the direction of the arrow d so that the sensor lever 24 is not opposed to the detection sensor 26 and the presence of paper is detected.

When the printing paper runs out, the detection cam 27 rotates in the direction opposite to the arrow g and returns, whereby the swinging member 29 also rotates in the direction opposite to the arrow h, and the pendulum 22 having no pressing force moves against the arrow c due to its own weight.
The sensor lever 24 also rotates in the direction opposite to the arrow d and returns, and faces the detection sensor 26 to detect the absence of paper.

Here, since the pendulum 22 rotates against its own weight only in one direction in the direction of arrow c, the oscillating body 29 is contacted with its front portion 29a and rear portion 29b facing the side surface of the pendulum 22. By arranging the pendulum 22 so as to be in contact therewith, as described above, when the pendulum 22 pivots in the direction of the counter arrow c and returns by its own weight, it can serve as a stopper that restricts pivotal movement of the pendulum 22.

〔The invention's effect〕

According to the present invention described in detail above, the paper shoots are provided to the platen in three directions, and one of the paper shoots from the three directions is rotated in one direction by the printing paper entering the paper shoot. First to move
And a second detection cam that rotates in both directions depending on which paper chute the printing paper has entered between the remaining two paper chutes. One pendulum that interlocks with the rotation due to the entry of the printing paper is provided, and in response to the bidirectional rotation of the second detection cam, the pendulum counters its own weight and transmits the rotation of the first cam. An oscillating body for transmitting the rotation to the pendulum is provided so that the pendulum swings in the same direction as the direction of receiving and rotating.
The sensor lever that rotates in conjunction with the rotation of this pendulum
It is provided in the same direction as the pendulum with respect to the fulcrum of rotation, and the detection sensor is placed facing this sensor lever.When print paper is fed into each paper chute, the sensor lever operates via the detection cam. It becomes possible to detect the presence of the printing paper by the detection sensor, and even if the printing paper is fed to the paper chute in any of the three directions, it is possible to detect it by one detection sensor. .

In addition, when the sensor lever is returned to its original position, the pendulum and the sensor lever's own weight are used, and since the pendulum can swing only in one direction from the stationary position, a simple structure ensures reliable operation. Can be done.

Further, since the detection cam detects the printing paper with each paper chute, the conveyance path of the printing paper can be arranged without difficulty.

[Brief description of drawings]

FIG. 1 is a perspective view of a detection mechanism showing an embodiment of the present invention, and FIG. 2 is a side view of a main part showing a case of friction feed,
FIG. 3 is a side view of an essential part showing a case of a tractor feed, FIG. 4 is a side view of an essential part showing a case of a bottom tractor feed, and FIG. 5 is a side view of a conventional example. 1 …… Platen 1a …… Detection groove 2 …… Print head 14 …… First paper chute 15 …… Second paper chute 16 …… Third paper chute 19 …… Detecting cam 22 …… Pendulum 24 …… Sensor lever 26 …… Detection sensor 27 …… Detection cam 29 …… Oscillator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toshiyuki Sato Inventor Toshiyuki Sato, No. 1 Sasakino, Fukushima City, Fukushima Prefecture Tohoku-oki Denki Co., Ltd. (56) Reference JP 62-225377 (JP, A) JP 60 -240273 (JP, A) Actually opened 60-168959 (JP, U)

Claims (1)

[Claims] 1. A paper chute is provided in the platen from three directions, and one of the paper chute from three directions is rotated in one direction when a print sheet enters the paper chute. A detection cam is arranged, and a second detection cam that rotates in both directions is arranged between the remaining two paper chutes depending on which paper chute has entered the paper chute. One pendulum that is interlocked with the rotation of the printing paper when it enters is provided, and in response to the bidirectional rotation of the second detection cam, the pendulum counters its own weight and transmits the rotation of the first cam. An oscillating body that transmits rotation to the pendulum is provided so as to swing in the same direction as the direction in which the pendulum is received and rotated, and a sensor lever that rotates in conjunction with the rotation of the pendulum,
A print medium detection mechanism for a printer, characterized in that a detection sensor is arranged in the same direction as a pendulum with respect to a fulcrum of rotation, and a detection sensor is arranged opposite to this sensor lever.