JPS622129Y2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Technical Field of the Invention The present invention relates to the printing paper feeding mechanism of printers and the like, and particularly relates to improvements in the printing paper type switching and paper end detection mechanism for continuous paper.

(2) Technical background Recently, various printers have been developed and put into practical use for computer terminals, etc. In many cases, the printing paper for these printers is a combination of single sheets and continuous sheets such as continuous slips having feed holes on both sides of the sheet. The paper sheet is used by wrapping it directly around the platen from the paper guide, or by inserting it into a printer equipped with a front inserter. Further, the continuous paper stored in the paper feed section is used by setting a paper feed hole in the sprocket of the medium transfer section, passing through a paper guide, and winding it around the platen member. It is equipped with a detector that indicates the paper end of continuous paper, but when using a single mark, this detector is always switched to the paper present state.

(3) Prior art and problems Hereinafter, a conventional method will be explained using a wire dot printer as an example with reference to FIGS. 1 to 4. 1st
The figure is a plan view illustrating a wire dot printer.
2 is a side view showing the medium feeding mechanism shown in FIG. 1, and FIGS. 3 a and 3 b are side views illustrating the detection section shown in FIG. 2. In the figure, 1 is a detection part, 2 is a micro switch, 2a is a contact, 3 is a detection lever, 3a is a contact part, 4 is a toggle spring, 10 is a platen, 1
1 is a printing paper, 12 is a medium transport section, 12a, 12
b is a sprocket, 12c is a paper holding plate, 12
d is a tractor, 13 is a carrier, 15 is a guide shaft, 16 is a feed screw, 17 is a belt, 19 is a motor, 20 is an ink ribbon cassette, 20a is an ink ribbon, and 21 is a printing head.

As shown in FIG. 1, the wire toad printer has a side frame 9, on which a platen 10 is rotatably supported. A printing paper 11 is wrapped around the platen 10, and the printing paper 11 is wrapped around the sprocket 12.
a, 12b, etc., in the direction of arrow A in the figure.
On the other hand, on the front side of the platen 10, that is, on the lower side in the figure, a carrier 13 is slidably fitted into a guide shaft 15 provided parallel to the platen 10; It is threadedly engaged with the feed screw 16. Feed screw 16
is connected to a motor 19 via a belt 17 or the like, and therefore, the feed screw 16 can move the carrier 13 in the directions of arrows C and D in the figure by rotating the motor 19 in forward and reverse directions. An ink ribbon cassette 20 is mounted on the carrier 13, and an endless ink ribbon 20a is built into the cassette 20 with a portion thereof exposed to the platen 10 side. The carrier 13 also has a print head 21.
is installed surrounded by an ink ribbon cassette 20, and the print head 21 is provided with a plurality of print magnets for forming prints with dots. Normally, 7 to 24 printing magnets are provided.

Further, the medium feeding mechanism is installed at the right end as shown in FIG. is supported by The continuous printing paper 11 is attached to the sprockets 12a and 12b of the paper transport section 12.
is set and held down by the paper holding plate 12c. The detection section 1 is located behind the medium transfer section 12, and is composed of a micro switch 2 and a detection lever 3, which are attached to sandwich a cutout window provided in the paper guide 14 from above and below. One end of the detection lever 3 is rotatably attached to the side frame as shown in Figure 3a, but since a toggle spring 4 is attached, it can be erected vertically in the direction of arrow E as shown by the two-dot chain line. When the lever 3 is tilted horizontally in the direction of arrow F, the tip contact portion 3a of the detection lever 3, which is biased by the toggle spring 4, touches the printing paper 1.
If there is a paper 11, touch that surface, and if there is no paper 11, press the contact 1a of the micro switch 2 to turn it on, looking in the direction of the arrow G through the cutout window of the paper guide 14, as shown in Figure 3b. It's becoming like that. When it is ON, it is in the "out of paper" state.
The detection lever has a length corresponding to the minimum width of the printing paper 11 when one side of the medium transport section 12 is moved to the innermost side.

When using continuous paper, the printing paper 11 is guided on the paper guide 14, and the contact portion 3a of the detection lever 3 is pressed by the elasticity of the toggle spring 4 on top of the paper guide 14. At this time, the contact portion 3a is blocked by the printing paper 11 on the paper guide 14 and is away from the contact 2a of the micro switch 2, so the micro switch 2 is in the OFF state, that is, "paper present".
It is in a state of

With this configuration, when the print head 21 operates, the print wire of the print magnet collides with the print paper 11 on the platen 10 shown in FIG. 1 via the ink ribbon 20a, and printing is performed. is arrow D with carrier 13
Printing is performed on the printing paper 11 while moving in the direction. When one line of printing is completed, the medium transport section 12 shown in FIG. 1 is driven to transport the printing paper 11 in the direction of arrow A by a predetermined tension amount in order to perform a line feed.
That is, when using continuous paper, the print paper 11 is stored in a paper feed section (not shown), and its leading edge is guided by the paper guide 14 and detected by the micro switch 2 of the detection section 1, as shown in FIG. The paper passes between the levers 2 and below the medium transfer section 12 and is wrapped around the platen 10. Sprockets are set in the sprockets 12a and 12b on the upper surface of the medium transfer section 12, and the paper is held down by the paper press plate 12c. , line feed, etc., to the rear part of the printer, that is, in the direction of arrow B in the figure.

Here, when the print paper 11 stored in the paper feed section is used up and the end of the print paper 11 passes the detection section 1, the detection lever 3 turns on the micro switch 2 as shown in the figure. The paper end warning lamp lights up when printing paper 11.
can be resupplied. When using a single mark, if the detection lever 3 is set vertically, the micro switch 2 will always remain OFF and in the "paper present" state, allowing switching between continuous paper and continuous paper. In addition, a method for controlling the printer by installing a mechanism (hereinafter referred to as a front inserter) that automatically sets a small print medium such as a single mark on such a printer, that is, the condition is that the micro switch 2 does not detect the lever 3. Additionally, devices are known that control the inserter mechanism in the same manner as the paper feed mechanism and platen feed. However, in the above method, when using the front inserter, the printing paper 1
When a single mark is used in 1, the long detection lever 3 is vertically erected and protrudes into the operation area, which not only obstructs printer operation, but also has the disadvantage that the detection lever 3 may be damaged. Furthermore, even if the device is not equipped with a front inserter as described above, even if the operator makes a mistake by forgetting to push down the detection lever 3 when switching to continuous paper 11 and setting it, the printing operation will continue and the paper end cannot be detected. There are some drawbacks.

(4) Purpose of the invention The purpose of the present invention is to solve the above-mentioned drawbacks, and to provide an improved medium feeding mechanism in which a switching section is attached to the medium detection section.

(5) Structure of the invention The present invention includes a medium transport unit that transports printing paper, a paper guide that guides the printing paper, a platen member around which the printing paper is wound and printing is performed, and the existence of the printing paper. In a medium feeding mechanism that sends printing paper when the detection part detects the presence of paper, the detection part is attached to the medium transport part, and the detection part is provided with a switching lever. The switching lever has an upper end positioned parallel to the upper surface of the medium transfer unit, a lower end located close to the detector of the detection unit, and by switching the upper end left and right, the lower end is positioned parallel to the upper surface of the medium transfer unit. This is a medium feeding mechanism characterized in that it is configured to open and close a child. By doing so, the purpose can be achieved.

(6) Embodiment of the invention An embodiment of the invention will be described below with reference to FIGS. 4 to 6. 4 is a side view showing an embodiment of the present invention, FIG. 5 is a plan view of FIG. 4, and FIG. 6 is an enlarged side view of the detection section of FIG. 4. In the figure, 1' is a detection part, 2' is a micro switch, 2'a is a contact, 5 is a shaft, 6 is a T-shaped switching lever, 6a is a lever arm, 6b is a lever, 7 is a detection lever, and 7a is a bending part , 7b is a sled portion, and 8 is a toggle spring. In addition, the same parts as in FIGS. 1 to 3 a and b are indicated by the same numbers.

As shown in FIG. 4, a microswitch 2' is attached to the lower part of the medium transfer section 12 with the contact 2'a facing downward. A shaft 5 is attached to the right side in the rear view of the micro switch 2', and two lever arms 6a of a T-shaped switching lever 6 are attached to this shaft 5.
The lower end of the detection lever 7 and the center of the detection lever 7 are rotatably attached. The upper end of the T-shaped switching lever 6 is located on the surface of the sprockets 12a, 12b of the medium transfer section 12, and the lower end of the detection lever 7 is located so as to lightly touch the contact 2'a of the micro switch 2'. . A T-shaped switching lever 6 is attached to the upper end of the detection lever 7.
There is a bent portion 7a that engages with. T-type switching lever 6
The lower end of one lever arm 6a has a sled-shaped portion 7b.
is bent, and a lever 6b is formed laterally at the lower end of the other lever arm 6a. A toggle spring 8 is attached to the end of the lever 6b. Now in FIG. 6, the T-type switching lever 7
When point a is pressed and rotated clockwise as shown by the two-dot chain line, the engaging bent portion 7a rotates clockwise, and as a result, the tip of the sled portion 7b of the detection lever 7 aligns with the micro switch 2'. Press contact 2'a
It is set to be turned on. Further, when the micro switch 2' is OFF, an alarm lamp (not shown) lights up.

With this configuration, when using continuous paper, the printing paper 11 is switched to the micro switch 2'.
When the contact 2'a of the micro switch 2' is inserted between the contact 2'a of the micro switch 2' and the tip of the curved part 7b of the detection lever 7, the contact 2'a of the micro switch 2' is pressed by the printing paper 11 and turned ON, indicating that "paper is present". The state will be as follows. Furthermore, paper guide 1
4, wrap it around the platen 10 and set it on the sprocket 12a, then the T-shaped switching lever 6
It will pass through the top. When the printing paper 11 is used up and the end passes through the detection section 1', the micro switch 2' is turned OFF, indicating "out of paper", and the paper end warning lamp lights up, so replenish the printing paper 11. can be done.

Next, when using the front inserter, print paper 11
To switch when using a single mark, press point a on the T-shaped switching lever 6 in Fig. 6 and rotate it clockwise to switch between the contact 2'a of the micro switch 2' and the detection lever 7.
Even if there is no printing paper 11 between the tip of the sled portion 7b and the tip of the sled portion 7b, the micro switch is turned on and becomes in the "paper present" state, and the toggle spring 8 maintains that position. It can also be seen that the point b of the T-shaped switching lever 6 protrudes from the surface of the sprocket 12a and is in the state of being in use. When switching from using single sheets to continuous paper, press point b of this T-shaped switching lever 6.
If you press and turn it counterclockwise, micro switch 2' will be turned OFF and the paper end warning lamp will turn on when there is no paper, so if you set paper 11, micro switch 6 will turn ON and the warning lamp will go out.

In this way, when using single sheets, the T-shaped switching lever 6 protrudes, and not only does it visually attract attention when switching to continuous paper 11, but it also gets in the way when setting the paper 11 on the sprockets 12a and 12b. This prevents forgetting operations.

(7) Effects of the invention As explained above, according to the invention, unlike the conventional method, the detection lever does not get in the way, and the T-shaped switching lever is installed at the continuous paper setting position, so when using single sheets, it is possible to Since the part protrudes, it is possible to prevent the operator from forgetting to switch the lever due to operator error when switching to and setting continuous paper. Therefore, there is an effect that the paper end detection function when using continuous paper and the switching function when using single sheets can be effectively performed.

[Brief explanation of the drawing]

FIG. 1 is a plan view illustrating a wire dot printer, FIG. 2 is a side view showing the medium feeding mechanism in FIG. 1, FIGS. 3 a and b are side views illustrating the detection unit in FIG. 2, and FIG. is a side view showing an embodiment of the present invention;
5 is a plan view of FIG. 4, and FIG. 6 is an enlarged side view of the detection section of FIG. 4. In the figure, 1 and 1' are detection parts, 2 and 2' are micro switches, 2a and 2'a are contacts, 3 and 7 are detection levers, 3a is a contact part, 4 and 8 are toggle springs, and 5 is a shaft. , 6 is a T-shaped switching lever, 6a is a lever arm, 6b is a lever, 7a is a bent portion, and 7b is a warped portion.

Claims (1)

[Scope of utility model registration request] Consisting of a medium transport unit that transports printing paper, a paper guide that guides the printing paper, a platen member around which the printing paper is wrapped around and printing is performed, and a detection unit that detects the presence of the printing paper, When the detection section detects the presence of paper, in the medium feeding mechanism that transports the printing paper, the detection section is attached to the medium transfer section, and a switching lever is attached to the detection section, and the switching lever is , an upper end is located parallel to the upper surface of the medium transfer part, a lower end is located near the detector of the detection part, and the lower end opens and closes the detector by switching the upper end. media feeding mechanism.