JPH0661990B2 - Ribbon tape transport device for printers operating in series - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a ribbon tape conveying device in a printer operating in series, particularly a thermal transfer printer, which moves at right angles to the feeding direction of a record carrier to be printed. Possible slider is provided, which has a print head for crimping the ribbon tape onto the record carrier,
Furthermore, the slider is provided with an unwinding mandrel and a take-up mandrel for receiving two take-up reels for the ribbon tape, and further connected to the take-up mandrel via a mechanical coupling. The present invention relates to a type in which a winding motor is provided.

[Conventional technology]

A device of this kind is known from DE-OS 360 2011. According to this, the thermoprint head is arranged on a slider together with an unwinding mandrel and a take-up mandrel for receiving two take-up reels for storing one ribbon tape provided in a ribbon cassette. The slider is movably arranged along the print cylinder. A take-up motor consisting of a step motor is carried on this slider, which is mechanically connected to the take-up mandrel via a gear transmission and a sliding coupling.
The sliding coupling comprises a plurality of clutch plates and a felt portion located therebetween. During printing on a record carrier (generally an ordinary type of paper), the ribbon print portion located between both take-up reels is pressed onto the record carrier by the thermoprint head, and the thermoprint head is slid. Drives to move in the row direction.
The heat release of the print head then transfers the ink from the ribbon tape onto the record carrier.

In order to obtain a good quality print, first, there is no relative movement between the ribbon tape and the record carrier during the printing process, and second, the ribbon tape is guided under tension.
Therefore, it is important to separate from the record carrier immediately after transferring the ink. For this reason, in the known device, the step motor is controlled in synchronization with the movement of the slider. In that case, the transmission ratio of the gear transmission is selected such that the rotational movement on the drive side of the sliding coupling is greater than the ribbon tape winding speed defined by the traveling speed of the slider. Since the ribbon tape is fixedly held between the thermoprint head and the record carrier, the rotational movement of the sliding coupling on the drive side is reduced until the winding speed of the ribbon tape matches the running speed of the slider. The friction torque generated in the sliding coupling produces the desired tension on the ribbon tape.

Based on "IBM Technical Disclosure Bulletin", Vol. 24, 7B (December 1981), page 3950, a similar device for the transport of ribbon tape is known, according to which the movement of the slider is synchronized. Instead of a take-up motor, a capstan drive is used to generate a rotary movement, which drives the ribbon tape via the switching coupling.

The conventional device requires relatively high construction costs due to the use of sliding couplings. Moreover, the desired tension of the ribbon tape depends on the wear and dirt of the sliding coupling.

[Configuration of the present invention]

According to the construction of the invention, in the device described at the beginning, the coupling consists of a permanent coupling and the winding motor consists of a small direct current motor, which directs a winding torque on the winding mandrel during the recording process. Is loaded by. In this case, the small direct current motor provides the winding torque for the ribbon tape at a significantly lower rotational speed for the motor, which is defined by the running movement of the slider.

[Operation and effect of the present invention]

A significant advantage of the present invention is that the construction costs for obtaining the winding torque for the ribbon tape are very low. This is because it only requires a simple small DC motor for this. The direct current that loads the small direct current motor can be easily extracted from the supply voltage of the printer including the device of the present invention. According to the results of the endurance test, the low rotation speed of the small direct current motor that produces the winding torque for the ribbon tape does not adversely affect the slip ring and the motor bearing.

A further advantage of the present invention is that by using a permanent coupling instead of a sliding coupling, the winding torque for the ribbon tape does not depend on uncontrollable parameters such as the lubricating state of the sliding coupling, It can be accurately adjusted according to the magnitude of the direct current supplied to the small DC motor. For the same reason, the winding torque and thus the ribbon tape tension do not fluctuate for a long time. Furthermore, the winding torque is changed very easily by the change of the direct current applied to the small DC motor, and is easily interrupted when the slider is returned after printing one row, for example. In known devices, this generally requires additional switching coupling.

In a further advantageous design of the invention, which is particularly simple in construction, the winding mandrel is arranged directly on the shaft of the small direct current motor. In the known device, a gear transmission is provided for pre-adjustment of the rotational speed, but according to the present invention, the direct current small motor is braked by the tension of the ribbon tape, and accordingly, the low rotational speed of the direct current small motor is reduced. The transmission can be dispensed with because it directly results from the traveling speed of the slider.

Taking advantage of the single dependence of the winding torque on the direct current supplied to the direct current small motor, in a further advantageous configuration of the invention, an adjustable ribbon tape type switch for the adjustment of different direct currents is provided. It is provided. This switch makes it possible to adapt the tape tension to be adjusted, depending on the different types of ribbon tape, in a particularly simple manner. By easily switching this switch, for example, in a thermo-ribbon tape that can be used only once (single use), the ribbon tape tension is adjusted to a high level in order to improve ink separation in the printing area, and it can be used several times. (Use) The ribbon tape tension is adjusted low in order to avoid residual deformation of the ribbon tape.

In a further advantageous configuration of the invention in this connection, the ribbon tape cassette is provided with a detectable mark when the ribbon tape is stored in the ribbon tape cassette and the ribbon tape type switch is provided with a mark. It is coupled to the detection member. When the ribbon tape cassette is inserted into the apparatus of the present invention, the detection of the unique mark of the ribbon tape cassette is selectively performed optically, electrically or mechanically by the mark detecting member. Correspondingly, the marks on the ribbon tape cassette are optionally formed in the form of visible mark members, conductive contact members or protrusions or recesses.

In connection with the adjustment of the ribbon tape tension, a direct current small motor is connected to a direct current voltage via a controllable resistance device connected in series, this resistance device being connected to the connection of the direct current small motor at its control input. You have been returned. Based on this negative feedback, the terminal voltage of the small DC motor acts in a negative feedback manner on the direct current flowing through the small DC motor, and as a result, the tension generated in the ribbon tape is on the take-up reel located on the take-up mandrel. It is irrelevant to the instantaneous winding radius of the ribbon tape. In the known device, the friction torque in the sliding coupling produces a ribbon tape tension that depends on the winding radius of the ribbon tape, but according to the device of the present invention, the DC small motor rotation speed that depends on the winding radius has its terminal voltage and current. Is detected via the control signal and is used to control the current supply and thus the torque of the small DC motor in the direction in which the ribbon tape tension is kept constant.
In addition, the small direct current motor is switched off particularly easily on return of the slider via the control input of the controllable resistance device.

In order to keep the ribbon tape tension constant, it is also possible to directly detect the instantaneous winding radius of the ribbon tape on the winding reel on the winding mandrel. For this purpose, according to the device of the present invention, a detection device for detecting the winding radius of the ribbon tape is arranged in the region of the winding mandrel, and this detection device is used for various types of small DC motors. Adjusting members for adjusting different direct currents are connected. In that case, the detection device can be formed in the form of a tentacle lever, which contacts the outer circumference of the winding radius of the ribbon tape of the take-up reel and, depending on the detected winding radius, a small DC motor. Adjust the potentiometer in the current circuit, or connect the resistor in the current circuit via a switch.

〔Example〕

FIG. 1 shows, as an important part of the present invention of a thermal transfer printer operating in series, the recording carrier 2 in the feeding direction, that is, arrow 3
1 shows a print cylinder 1 conveyed in the direction of. As the record carrier 2, ordinary type paper is generally used. A slider 4 is movably supported by two guide bars 5, 6 parallel to the axis of the printing cylinder 1. The movement of the slider is carried out parallel to the printing cylinder 1 in the direction indicated by the double arrow 7 by a rope or belt drive, not shown, in a known manner. A thermoprint head 8 is arranged on the slider 4 in the immediate vicinity of the print cylinder 1 and can be pivoted toward or away from the print cylinder by a drive device (not shown). Further, the unwinding side mandrel 9 is projected on the slider 4 in the printing direction, that is, the position shifted to the right, and the winding mandrel 10 is projected in the direction opposite to the printing direction, that is, the position shifted to the left, Both are rotatably supported about their respective axes. The winding mandrel 10 is directly mounted on the shaft 11 of the small DC motor 12, and the small DC motor is fixed to the slider below the slider. DC small motor 12
The direction of rotation of is counterclockwise as indicated by the arrow. The slider 4 is further provided with a ribbon tape type switch 13, which is provided with mark detecting members 14 and 15 composed of two micro switches. Further, devices such as a ribbon tape cassette detector or a ribbon tape end sensor (not shown) as well as a drive for pivoting the thermoprint head 8 already mentioned are DE-OS 3602.
It may be formed similarly to the thermoprinter disclosed in 011.

The unwinding side mandrel 9 and the winding mandrel 10 are rotatably arranged in a ribbon tape cassette 18 and are made of a heat-sensitive ribbon tape 19.
Serves to load and drive the two take-up reels 16, 17 that have stored the. When the ribbon tape cassette 18 is mounted on the slider 4, the ribbon tape 19 is located between the take-up reels 16 and 17 between the thermo print head 8 and the record carrier 2 on the print cylinder 1. Is guided inside the ribbon tape cassette 18 so as to be located at. The ribbon tape cassette 18 is provided with marks 20 in the form of protrusions and cutouts on the longitudinal side surface thereof. This means that when the ribbon tape cassette 18 is mounted on the slider 4, the mark detecting member 1 of the ribbon tape type switch 13 is mounted.
Adjust 4, 15 depending on the code. The mark 20 indicates the ribbon tape 1 stored in the ribbon tape cassette 18.
Represents 9 types.

FIG. 2 is a schematic diagram of an electric circuit of the small DC motor 12. The small DC motor 12 is connected at one connection to a DC voltage V + via a controllable resistance device 21 connected in series and formed by a transistor,
The other connecting portion is connected to the current detection resistor 22.
The base connection of the transistor is a controllable resistance device 21
The control input section 23 is formed. The evaluation device 24 is connected in parallel to the DC small motor 12, and the first input section 25 thereof detects the terminal voltages on both sides of the DC small motor,
The second input section 26 is connected to both sides of the current detection resistor 22 and detects the current flowing through the small DC motor 12.
The evaluation device 24 produces an output signal at its output 27, which is proportional to the instantaneous ribbon tape tension, depending on the signals detected at its two inputs 25, 26. Since the ribbon tape tension or the ribbon tape tension force is equal to the quotient of the torque and the ribbon tape winding radius of the winding reel 17, the constant winding speed of the ribbon tape 19 corresponds to the running speed of the slider 4. At this time, the number of revolutions of the small DC motor 12 is inversely proportional to the winding radius of the ribbon tape, and therefore the ribbon tape tension depends proportionally on the product of the torque and the number of revolutions. In the evaluation device 24, the torque and the rotational speed are derived from the detected terminal voltage of the DC small motor 12 and the current flowing through the DC small motor based on the known parameters of the DC small motor, and the instantaneous ribbon tape is derived from this. Tension is required. The output unit 27 of the evaluation device 24 is the first of the comparison devices 29.
Of the comparator 29 and the second input 30 of the comparator 29 is connected to a voltage divider consisting of resistors 31, 32, 33, 34. The DC voltage V ₊ is applied to the voltage divider. The voltage divider pre-adjusts the desired ribbon tape tension. Two resistors 32 for this,
33 is selectively connected in parallel to or cut off from the resistor 34 via the mark detecting member or the micro switches 14 and 15, respectively. The comparison device produces a difference signal corresponding to the difference between the actual value of the ribbon tape tension and the set value. The output of the comparison device is connected via a resistor 35 to the control input 23 of the controllable resistance device 21 and is operated by a control device of the thermal transfer printer, in this case simply block 36. It is also connected to a short circuit switch 37 in the form of a transistor.

To print a line on the record carrier 2, the slider 4 moves with the thermoprint head 8 to the right in the printing direction.
The thermoprint head 8 then swivels towards the printing cylinder 1 and presses the ribbon tape 15 onto the record carrier 2 in the printing area. At the same time, the ribbon tape 19 is heated by the thermoprint head 8 into spots corresponding to the print pattern, so that the ink transfer of the ribbon tape onto the record carrier 2 is carried out according to the print pattern. Since the thermoprint head 8 presses the ribbon tape 19 onto the recording medium 2, the relative movement between the ribbon tape 19 and the recording medium 2 is hindered, and as a result, the ink is not displaced despite the traveling movement of the slider 4. . During the printing of one line, the control device 28 causes the short-circuit switch 37 to remain open, so that the small direct current motor 12 is loaded by the direct current through the controllable resistance device 21 and the thermohead 8 and. It produces a continuous winding torque for the part of the ribbon tape lying between the winding mandrel 10 and the winding reel 17.
Since the ribbon tape 19 is fastened between the thermoprint head 8 and the record carrier 2, the small DC motor 12
Can rotate only at a speed permitted by the traveling speed of the slider 4. In short, the small DC motor 12 is constantly braked, and as a result, a winding torque that gives tension to the ribbon tape is generated. This causes the ribbon tape 19 to be separated from the record carrier 2 immediately after the thermoprint head, so that good quality printing is guaranteed, especially when so-called release ribbon tapes are used.

The ribbon tape tension for maintaining the tension of the ribbon tape is adjusted via the mark detecting member or the micro switches 14 and 15 depending on the mark 20 of the ribbon tape cassette 18. At that time, the base voltage of the transistor 21 changes according to the positions of the micro switches 14 and 15, and the DC voltage applied to the DC small motor and defining the torque thereof also changes correspondingly. If the winding torque of the small DC motor is constant, the ribbon tape tension gradually decreases as the winding radius of the ribbon tape on the winding reel increases as the printing process proceeds. DC small motor 12
Since the number of revolutions is directly dependent on the traveling speed of the slider 4, the number of revolutions decreases as the winding radius increases, and the terminal voltage of the small DC motor 12 decreases accordingly. However, due to the negative feedback of the controllable resistance device 21, the direct current supplied to the direct current small motor 12 via the evaluation device 24 and the comparison device equipped with the direct current small motor 12 increases, and as a result, the direct current small motor is obtained. The winding torque produced by 12 is increased to compensate for the ribbon tape tension loss discussed above.
In this way, the ribbon tape tension is kept constant.

Especially when using ribbon tape that is used several times,
The unwinding side mandrel 9 can also be driven by a motor so as to enable the rewinding of the ribbon tape.

[Brief description of drawings]

FIG. 1 is a schematic diagram of one embodiment of the present invention, and FIG. 2 is a control circuit diagram for the small DC motor of FIG. 1 ... print cylinder, 2 ... record carrier, 3 ... arrow, 4 ...
... Slider, 5,6 ... Guide bar, 7 ... Double arrow, 8 ...
… Thermoprint head, 9 …… Unraveling side mandrel, 10 ……
Winding mandrel, 11 ... Shaft, 12 ... Small DC motor (winding motor), 13 ... Ribbon tape type switch, 14,
15 ... Mark detecting member, 16, 17 ... Take-up reel,
18 ... Ribbon tape cassette, 19 ... Ribbon tape, 20 ... Mark, 21 ... Resistor device, 22 ... Current detection resistor, 23 ... Control input section, 24 ... Evaluation device, 2
5 ... 1st input part, 26 ... 2nd input part, 27 ...
Output unit, 28 ... First input unit, 29 ... Comparison device, 3
0 ... second input section, 31, 32, 33, 34, 35 ...
... resistor 36 ... block, 37 ... short-circuit switch.

Claims (6)

[Claims] 1. A ribbon tape (19) transport device for a printer operating in series, in particular a thermal transfer printer, which slider is movable at right angles to the feeding direction (3) of a record carrier (2) to be printed. (4) is provided, the slider (4) is provided with a print head (8) for crimping the ribbon tape (19) to the record carrier (2), and further, the slider (4) is provided with a ribbon tape (8). (1
A take-up mandrel (9) and a take-up mandrel (10) for receiving two take-up reels (16, 17) for a take-up mandrel (9) are arranged, and the take-up mandrel (10) further comprises a machine. Of the type in which a take-up motor (12) is provided which is connected via a conventional coupling, the coupling consisting of a permanent coupling, the take-up motor (12) consisting of a small direct current motor, this motor recording A ribbon tape transport device in a printer operating in series, characterized in that a winding mandrel (10) is loaded by a direct current which produces a winding torque during the process. 2. The winding mandrel (10) is a small DC motor (1).
The ribbon tape transporting device according to claim 1, which is directly attached to the shaft (11) of (2). 3. The ribbon tape transporting device according to claim 1, further comprising an adjustable ribbon tape type switch (13) for adjusting different direct currents. 4. A ribbon tape cassette (18) storing a ribbon tape (19) is provided with a detectable mark (20), and further, a ribbon tape type switch (13).
The ribbon tape transporting device according to claim 3, wherein the mark is connected to the mark detecting member (14, 15). 5. A small direct current motor (12) is connected to a direct voltage (V ₊ ) via a controllable resistance device (21) connected in series, the resistance device being at its control input side. The ribbon tape transporting device according to any one of claims 1 to 4, wherein negative feedback is provided to a connecting portion of the small DC motor (12). 6. A detection device for detecting the winding radius of the ribbon tape on the take-up reel is arranged in the region of the winding mandrel, and further for adjusting different direct currents for a small direct current motor. 5. The ribbon tape transporting device according to claim 1, wherein an adjusting member is connected to the detecting device.