JPS60122186A - Ribbon cassette driving device for thermal printer - Google Patents

Abstract

PURPOSE:To simplify construction, by a method wherein an operation for bringing a thermal head into contact with a platen and separating the head from the platen and an operation for transmitting rotation to a ribbon-driving shaft and interrupting the rotation are effected by a single driving part. CONSTITUTION:When a ribbon cassette is fitted to the upper face of a carrier 4, reels in the cassette are connected respectively to the ribbon-driving shaft 15 and a driven shaft 16. When the carrier 4 is moved in a printing direction under this condition, printing is conducted. Namely, a driving gear 13 meshed with a rack 17 is rotated clockwise , and the shaft 15 is rotated counterclockwise together with a tooth part 14 to take up the printing ribbon from the right reel onto the left reel. When the carrier 4 is returned leftward, a magnet 23 is excited. By this, an arm 20 is deviated downward, whereby the rack 17 is disengaged from the gear 13, a movable body 10 is turned by being pushed by an engaging piece 25, and the thermal head 11 is separated from the platen 1. Accordingly, the ribbon is not fed when returning the carrier.

Description

TECHNICAL FIELD OF THE INVENTION This invention relates to a ribbon force set drive for a thermal printer.

Technical background of the invention and its problems Conventionally, printing was performed by moving a carrier carrying 4't' on a thermal head and a ribbon cassette to the right along a platen, and in this process, printing was performed from the right reel of the ribbon cassette. By taking printing ribbons f, c, and Y6 on the left reel, the printing ribbon can be pulled out in front of the platen without moving relative to the paper during printing.
: It (from the 4th paper, l:+l and wind it,
There is a thermal printer in which ribbon feeding is interrupted and the thermal head is withdrawn from the platen 17 when the carrier is returned to the left. The multi-head is generally moved toward and away from the platen by a drive unit such as an electromagnet. Additionally, as a ribbon feeding mechanism that converts the linear motion of the carrier into rotational motion and fully rotates the ribbon drive shaft, a wire or belt is wound around a pulley attached to the carrier, and both ends of the wire or belt are extended in the left-right direction. A carrier is used in which the carrier is fixed with a ribbon drive shaft that receives the rotational force of the boot. but,
Since the power transmission between the pulley and the ribbon drive shaft must be interrupted during carrier return, the power transmission mechanism must be equipped with an idler gear, a clutch, etc., which complicates the structure.

Even when a ribbon feeding motor is mounted on the carrier, the motor is heavy and expensive, which is disadvantageous.

Purpose of the Invention The present invention has been made in view of the above points, and an object of the present invention is to provide a ribbon cassette drive unit for a thermal printer that can simplify the structure.

SUMMARY OF THE INVENTION In the present invention, when a carrier is moved in the printing direction, a movable body that holds a thermal head is advanced toward the platen, and a rack is engaged with a drive gear attached to the carrier, so that the ribbon drive shaft on the carrier is moved from the drive gear to the drive gear. When the carrier returns, it transmits rotational force to a single drive unit! The meshing between the driving gear and the rack is released, and the thermal head is retracted from the platen together with the movable body, and therefore, the 1# movement of contacting the platen with the slider and the rotation transmission to the ribbon drive shaft. The two operations of opening and closing can be carried out by one drive unit, and the structure for driving the printing ribbon can be achieved by simply connecting the drive gear that meshes with the rack directly to the ribbon drive shaft. This allows for a simple structure, and furthermore,
The configuration is such that the consumption of the printing ribbon is reduced by quickly cutting off the power transmission to the ribbon drive shaft during space feeding in the printing process.

Embodiment of the Invention A first embodiment of the invention will be described with reference to FIGS. 1 to 3. A ribbon cassette (not shown) is attached to the platen (11), flat carrier shaft (2), and guide (3).
A carrier (4) that removably holds is slidably held. A belt (5) to which -t'16 is fixed to the carrier (4) is wound around a pulley (7) directly connected to the carrier motor (6) and another pulley (8). Furthermore, the carrier (4) has a carrier shaft (2
) is held as a movable body u1 which rotates around a center and is urged by a spring (9) in the direction of the sliding platen (1). At one end of this movable body is a thermal head αυ.
is held, and an engagement piece Qz, which is an engagement portion, is formed at the other end.

Next, the carrier (4) is equipped with a ribbon drive shaft 0! having a tooth portion U4 that meshes with the drive gear OJ and this drive gear (to).
3 and a driven shaft QG are rotatably attached. In addition, an arm body having a rack αη on the guide (3) and refracting pieces α8(2) bent from both ends of this rack αη is swingably supported on the upper part of the support column Q, and this arm (4
) The rear part of the refracting piece a (to) is urged downward by a spring holder. Further, a plunger (c) with a magnet 4, which is a driving part, is rotatably attached to the arm holder. A retaining piece (c), which is a retaining portion that engages with the retaining piece azK, is formed on the arm (a).

In such a configuration, FIGS. 1 and 2 show the movable body α
1 is biased by the force of the spring (9), the thermal head a contacts the platen (1), and the boot AC2LI is biased by the force of the spring handle, causing the rack αη to mesh with the drive gear (2). state. When the ribbon cassette is placed on the top surface of the carrier (4), the reel inside the ribbon cassette is ribbon IAA 1i1+ 1lill.
(Is is connected to the driven shaft 0G. In this state, printing is performed when the carrier (4) is moved in the printing direction (rightward in Fig. 1). At this time, the drive gear meshing with the rack (lη) α] rotates clockwise, and the ribbon drive shaft αυ
The printing ribbon is rotated counterclockwise together with the crest U4 to wind the printing ribbon from the right reel to the left reel. carry r (4
) When returning to the left, press the magnet (c) 4)
1-j-ru. As a result, as shown in Fig. 3, the arm Ikei is deflected downward, the rack aη is rotated by the drive gear ([: out of cram school) 11, the movable body is pushed by the holding bar I+, and the thermal The head αυ separates from the platen (1). Therefore, should I feed the ribbon at the time of ghee/rear return? ) Don't jump.

In this way, the movement of the thermal head OD towards and away from the platen fl1 and the intermittent movement of the power to the ribbon drive shaft a9 are performed by one magnet fl3.
In addition, the ribbon can be fed by simply providing the drive gear αJ meshing with the rack 0η, the ribbon drive shaft a9, and the driven shaft 0() on the carrier, thus simplifying the structure. be able to.

Next, a second embodiment of the present invention will be explained based on FIGS. 4 to 6. The same parts as those in the actual hflj example are designated by the same reference numerals, and the description thereof will be omitted. CPU 4 is connected to a ROM (J) for setting programs, a RAM (c) with multiple work areas, and a known printing control circuit, and a magnet (e) connected to the arm (a). is connected to the CPU (a) via an interface (to).

Therefore, as shown in the flowchart of FIG. 5, is there a printing instruction for each character? If the judgment is NO, magnet flag 1 is set in the work area of RAM (c), and if YES, the magnet flag of the work area of RAM (c) is reset. Next, as shown in the flowchart of FIG. 6, is the magnet flag 1? is judged, and if it is No, the magnet wire will be turned on, and YE.
If it is S, magnet 4 will be OFF. This determination of ``Is there a printing command?'' and ``Is the magnet flag 1?'' is performed not only when the carrier returns, but also during the printing process in which the carrier (4) is moved to the right. Therefore, carry °γ(
4) to the right simply for space feeding, the excitation effect of the magnetic net causes the thermal head (10 to move away from the platen (1), and the driver 11jl
+ gear θ”, remove rack 0η and interrupt ribbon feeding 1
-1 for this.”

υ, printing ribbon consumption can be reduced by n'j.

Effects of the Invention Since the present invention is constructed as described above, a single drive unit can perform the movement of the thermal head toward and away from the platen, and the transmission and interruption of the rotational force to the ribbon drive shaft. Furthermore, the ribbon drive shaft can be selectively driven simply by advancing the arm that moves the rack relative to the drive gear of the carrier, which simplifies the structure of the ribbon feeding mechanism. You can, and furthermore,
Even during space feed, the ribbon feed υ is caused by the operation of the drive unit.
This has the effect of reducing the amount of printing ribbon consumed.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention, in which FIG. 1 is a plan view, FIG. 2 is an enlarged side view showing the state at the time of printing, and FIG. 3 is the state when not printing. 4 to 6 show a second embodiment of the present invention, FIG. 4 is a block diagram, and FIG. 5 is a flowchart showing determination of a printing command, and FIG. FIG. 6 is a flowchart showing the operation of the magnet. l...Platen, 4...Carrier, 1o...Movable body, 11...Thermal head, 12...Engagement piece (retention part), 13...Drive gear, 15... Ribbon drive shaft, 17... Rack, 2o... Arm, 23... Magnet (drive part) Applicant Tokyo Electric Co., Ltd.:, 1 -=-゛5Z Figure Z3 1 ■

Claims (1)

[Claims] 1. A carrier is provided that holds the ribbon cassette and reciprocates along the platen in the printing direction and the carrier return direction, and a movable body that holds the thermal root is mounted on this carrier. a simplex unit which can be freely deflected in the direction in which the multihead moves toward and away from the platen), and a J′-me having -t racks in the direction of movement of the carrier can be freely deflected in a direction perpendicular to the racks (tl). '-iR)' and attach the drive gear meshing with the rack and the ribbon drive shaft to the carrier in a connected state; 1) the arm No. 11 and the movable body are mutually engaged and interlocked; A retaining portion is provided that is connected to either one of the movable body and the arm to disengage the engagement between the rack and the drive gear and simultaneously remove the 13f movable body from the platen. 1. A ribbon cassette drive device for a thermal printer, characterized in that it is provided with a drive section for driving the ribbon cassette. 2. A carrier is provided that holds the ribbon cassette and moves back and forth along the platen in the printing direction and the carrier return direction, and a movable body that holds the thermal head on the carrier is moved when the thermal head approaches and separates from the platen. an arm having a rack in the direction of movement of the carrier is provided so as to be deflectable in a direction perpendicular to the rack, and a drive gear and a ribbon drive shaft that mesh with the rack are attached to the carrier. The arm and the movable body are installed in a connected state, and the arm and the movable body are provided with a retaining part that engages with and interlocks with the arm and the movable body, and is connected to either one of the movable body and the arm so that the arm and the movable body are connected to each other and are connected to each other in the space movement 9 of the printing process. and a ribbon cassette drive device for a thermal printer, further comprising a drive unit that disengages the rack from the drive gear O1I and simultaneously retracts the movable body No. 111 from the platen at the time of carrier return.