JPH048574A - Ink ribbon stop detector - Google Patents

Abstract

PURPOSE:To simplify a structure by providing a tension lever provided with a contact part elastically abutting on an ink ribbon and rotatably held on a carrier and a detection switch interfering with the tension lever. CONSTITUTION:When a ribbon cassette 5 is not loaded on a carrier 2, a projection 20 of an operation member 16 is elastically engaged with a recessed part 19 of the carrier 2. A tension lever 10 is pressed against an abutting part 15 of the operation member 16, and a roller 9 is held separately from a path of an ink ribbon 4. The ribbon cassette 5 can be easily loaded on the carrier 2 without the interference of the ink ribbon 4 with the tension lever 10. The tension lever 10 is rotated by being pressed by the abutting part 15 of the operation member 16 to press a movable contact plate of a detection switch 13 to keep the detection switch 13 in an ON state. When the ribbon cassette 5 is loaded, the ink ribbon 4 is depressed by the roller 9, the tension lever 10 is retracted from the detection switch 13, and the detection switch 13 is kept in an OFF state.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ink ribbon stop detection device used in a printer in which a ribbon cassette is detachably mounted on a carrier.

2. Description of the Related Art Conventionally, as shown in FIG. 5, a print head 3 and a ribbon cassette 22 are mounted on a carrier 2 that is driven back and forth along a platen 1, and an ink ribbon 4 is moved in the opposite direction to the moving direction of the carrier 2. There is a printer that prints while moving in the same direction. That is, during printing, the ink ribbon 4 is moved relative to the print head 3 to perform printing, but when the ink ribbon 4 stops, the same position of the ink ribbon 4 interferes with the print head 3 many times. As a result, differences in shading may occur in the print, or if the print head 3 is a dot printer head, the ink ribbon may be damaged by impact from the print bottle, or the print bottle may pierce the ink ribbon 4 and cannot be recovered. In this state, the ink ribbon 4
This may cause problems such as the printing bottle being broken.

For this reason, as described in Japanese Utility Model Application Publication No. 57-163348, an opening is formed in the ink ribbon cartridge, and an ink ribbon running detection mechanism member protruding from the outside is attached to the printer side. An invention has been proposed in which an interlocking roller is provided inside the cartridge that elastically contacts this ink ribbon running detection mechanism member, and the running state of the ink ribbon is detected by the rotational movement of the ink ribbon running detection mechanism member. be.

In addition, as described in Japanese Utility Model Application No. 59-68963, a tension lever is rotated by the tension of the ink ribbon, the rotational movement of the tension lever is detected by a microswitch, and the detection signal is used to drive the print head. There is an idea to control the operation of the motor that drives the carriage that holds the.

Furthermore, as described in Japanese Patent Application Laid-open No. 1-198382, a detection roller having a built-in permanent magnet and contacting the ink ribbon is rotatably provided in the carrier, and a detection portion facing the outer periphery of the detection roller is provided. There is an invention in which the running state of the ink ribbon is detected by detecting the rotational movement of a detection roller provided in a carrier with a detection section.

Problems to be Solved by the Invention The invention described in Japanese Utility Model Application Publication No. 57-163348 is as follows:
It is unlikely that the ink ribbon running detection mechanism member alone can output a signal, and the number of parts increases because an element that outputs a signal based on its rotational movement is required. Furthermore, when installing the ink ribbon cartridge into the printer, it is difficult to install the ink ribbon cartridge because it tends to interfere with the ink ribbon travel detection mechanism member. Furthermore, in the invention described in Japanese Utility Model Application Publication No. 59-68963 and the invention described in Japanese Patent Application Publication No. 198382, since the ink ribbon is not of a carrier-mounted type, when the ink ribbon is attached, the platen and the printing are printed. The operation is cumbersome because it is necessary to determine a path for passing the ink ribbon between the head and between multiple rollers.

Means for Solving the Problems The invention according to claim 1 includes: a carrier that holds a print head and is driven reciprocally along a platen; and a ribbon cassette that has a ribbon drive shaft and is detachably mounted on the carrier. a tension lever rotatably held on the carrier and having a contact portion that is biased in one direction and resiliently contacts the ink ribbon partially exposed from the ribbon cassette; and a detection switch that is held and interferes with the tension lever.

In the invention according to claim 2, a locking member having a contact portion that contacts the tension lever is displaceably provided on the carrier, and a locking portion that elastically engages with each other is formed on the carrier and the operating member. .

According to a third aspect of the present invention, the ribbon cassette is provided with a pressing portion that presses the operating member in a direction to release the engaged state of the locking portion, and the operating member is biased in a direction away from the tension lever.

The invention of claim 1 rotates a tension lever using the tension generated in the ink ribbon when the ink ribbon is run on a ribbon drive shaft, and detects the rotational movement of the tension lever with a detection switch, thereby rotating the ink ribbon. The running state can be detected, and a signal to detect the running of the ink ribbon can be output simply by providing a detection switch that detects the operation of the tension lever for applying tension to the ink ribbon. can be simplified.

According to the second aspect of the invention, since the tension lever can be retracted from the path of the ink ribbon using the operating member, it is possible to easily attach the ribbon cassette to the carrier.

According to the third aspect of the invention, when the ribbon cassette is mounted on the carrier, the operating member can be pressed by the pressing part to release the engagement state with the locking part of the carrier, and thereby the operating member can be moved to the tension lever. The ink ribbon can be moved away from the ink ribbon, and the tension lever can be rotated by the urging force to automatically apply tension to the ink ribbon.

Embodiment An embodiment of the present invention will be explained based on FIG. 1 and FIG. 4. Reference numeral 1 designates a platen, and a carrier 2 that is reciprocated along the platen 1 holds a print head 3, and a ribbon cassette 5 having an ink ribbon 4 is removably mounted thereon. This ribbon cassette 5 is formed with a pair of left and right arms 6.7 and a recess 8 located on one side, and the ink ribbon 4 is exposed between these arms 6.7 and in the recess 8. Further, the ribbon cassette 5 has a ribbon drive shaft (not shown) that winds up the ink ribbon 4 on the left side. Further, on the left side of the carrier 2, a tension arm 10 having a roller 9 at its tip which is a contact portion that contacts the ink ribbon 4 is biased clockwise by a torsion spring 11 and rotated by a support shaft 12. freely held. 13 is a detection switch attached to the carrier 2, and this detection switch 13 has a movable contact plate that contacts the tension arm 10 and a fixed contact plate. Furthermore, an opening 14 is provided on the left side of the carrier 2.
is formed in the opening 14, and the tension arm 1 is inserted into the opening 14.
An operating member 16 having an abutting portion 15 that abuts on the operating member 16 is biased leftward by a tension spring 17 and held so as to be slidable and displaceable in the vertical direction.

Further, the opening 14 has recesses 18 and 1 which are locking parts.
9 are formed at predetermined intervals, and these recesses 18.
Protrusions 20, which are locking parts that are selectively engaged with 19, are formed on both sides of the operating member 16.

Further, a pressing portion 21 for pressing the operating member 16 is formed on the bottom surface of the ribbon cassette 5.

In such a configuration, FIG. 2 shows a state in which the ribbon cassette 5 is not attached to the carrier 2, and (a
) is a plan view of the part, and (b) is a front view of the part. As shown in these figures, the protrusion 20 of the operating member 16
is elastically engaged with the recess 19 of the carrier 2. In this state, the tension lever 10 is attached to the contact portion 1 of the operating member 16.
5, the roller 9 is maintained in a state separated from the path of the ink ribbon 4. Therefore, the ribbon cassette 5 can be easily mounted on the carrier 2 without the ink ribbon 4 interfering with the tension lever 10. In addition, in this state, the tension lever 10 is pushed by the contact portion 15 of the operating member 16 and rotates, and the detection switch 1
The detection switch 13 is maintained in the on state by pressing the movable contact plate 3. FIG. 3 shows a state in which the ribbon cassette 5 is attached to the carrier 2. (a) is a plan view of a portion thereof, and (b) is a front view of a portion thereof. As can be seen from these figures, When installing the ribbon cassette, the operating member 16
is pushed downward by the pressing part 21, so the protrusion 20 is pushed into the recess 19.
The protrusion 20 is pulled leftward by the spring 17 and engages with the recess 18 on the left. That is, the tension lever 10 is released by the contact portion 15 of the operating member 16 and rotated clockwise by the biasing force of the torsion spring 11.
The ink ribbon 4 is pressed against the roller 9. In this state,
Since the tension lever 10 is retracted from the detection switch 13, the detection switch 13 is maintained in the off state. When a print signal is input in this state, the carrier 2 is also driven in synchronization with the print signal, and at the same time the ribbon drive shaft is driven and the ink ribbon 4 is wound up, but at this time, as shown in the plan view of FIG. In order to increase the tensile force of the ink ribbon 4, the tension lever 10 is rotated counterclockwise and presses the movable contact plate of the detection switch 13.
Turn on 3. In this way, the state in which the detection switch 13 is turned on while the print signal is input is considered normal, but the detection switch 13 continues to be turned off even though the print signal is input. In this state, it can be determined that the ink ribbon 4 is not running for some reason.

As described above, the running of the ink ribbon 4 can be detected simply by providing the detection switch 13 for detecting the operation of the tension lever 10, so the structure can be simplified. Furthermore, the tension lever lO is
Since the ribbon cassette 5 can be evacuated from the path of the ink ribbon 4, the ribbon cassette 5 can be easily attached to the carrier 2. Moreover, when the ribbon cassette 5 is installed, the pressing portion 21 can press the operating member 16 and displace the operating member 16 in the direction away from the tension lever 10, so that the roller 9 can be automatically attached to the ink ribbon 4. can be brought into contact.

Effects of the Invention As described above, the invention of claim 1 includes a carrier that holds a print head and is reciprocated along a platen, and a ribbon cassette that has a ribbon drive shaft and is detachably mounted on the carrier. a tension lever rotatably held on the carrier and having a contact portion that is biased in one direction and resiliently contacts the ink ribbon partially exposed from the ribbon cassette; and a detection switch that is held and interferes with the tension lever, so that the tension lever is rotated by the tension generated in the ink ribbon when the ink ribbon is run on the ribbon drive shaft, and the rotational movement of the tension lever is controlled. The running state of the ink ribbon can be detected by detecting it with a detection switch, and the running state of the ink ribbon can be detected simply by providing a detection switch that detects the operation of the tension lever to apply tension to the ink ribbon. Since a signal can be output, the structure can be simplified.

As described above, the invention according to claim 2 provides a locking member that is movably disposed on the carrier and has a contact portion that contacts the tension lever, and that the carrier and the operating member are elastically engaged with each other. By forming the section, the tension lever can be retracted from the path of the ink ribbon using the operating member, which has the effect of making it easier to attach the ribbon cassette to the carrier.

As described above, the invention of claim 3 provides a ribbon cassette with a pressing portion that presses the operating member in a direction to release the engaged state of the locking portion, and biases the operating member in a direction away from the tension lever. By doing so, when the ribbon cassette is attached to the carrier, the operating member can be pressed by the suppressing part to release the engagement state with the locking part of the carrier,
This has the effect of automatically causing the operation member to move away from the tension lever, rotate the tension lever by the urging force, and apply tension to the ink ribbon.

[Brief explanation of the drawing]

1 to 4 show an embodiment of the present invention,
Figure 1 is a perspective view, Figure 2 shows a state in which the ribbon cassette is not attached to the carrier, (a) is a partial plan view, (b) is a partial front view, and Figure 3 is a partial view. This shows the state in which the ribbon cassette is attached to the carrier. (a) is a partial plan view, (b) is a partial front view, and Fig. 4 is a partial plan view showing the running state of the ink ribbon. FIG. 5 is a perspective view showing a conventional example. l...Platen, 2...Carrier, 3...Print head, 4...Ink ribbon, 5...Ribbon cassette, 9...Contact part, 10...Tension lever 13
...detection switch, 15...contact part, 16...operation member, 18-20...locking part, 21...pressing part

Claims (1)

[Claims] 1. A carrier that holds a print head and is driven back and forth along a platen, a ribbon cassette that has a ribbon drive shaft and is detachably mounted on the carrier, and is biased in one direction. a tension lever rotatably held by the carrier and having a contact portion elastically contacting the ink ribbon partially exposed from the ribbon cassette; An ink ribbon stop detection device comprising a detection switch that interferes with the ink ribbon stoppage detection device. 2. A claim characterized in that an operating member having a contact portion that contacts the tension lever is displaceably provided on the carrier, and a locking portion that elastically engages with each other is formed on the carrier and the operating member. Item 1. The ink ribbon stoppage detection device according to item 1. 3. Claim 2, characterized in that the ribbon cassette is provided with a pressing part that presses the operating member in a direction to release the engagement state of the locking part, and urges the operating member in a direction away from the tension lever. The ink ribbon stop detection device described above.