JPS62240575A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To take-up an ink ribbon under constant tension without being affected by the size of the take-up reel diameter of the ink ribbon, by receiving the position detection signal of the ink ribbon outputted from a detection part for detecting the take-up tension of the ink ribbon to appropriately transmitting said signal to an ink ribbon driving motor. CONSTITUTION:When ink ribbon 11 is not taken-up, a position detection pin 14 is pushed to the end part of a slot 27 in a B-direction by an elastic member 15 but, when the ink ribbon 11 is taken-up, said pin 14 moves to a C-direction to be changed to a position where the tension of the ink ribbon is well-balanced with the energizing force of the elastic member 15 corresponding to said tension. The displacement of the position detecting pin 14 is detected as the voltage signal of a position detection signal F by a potentiometer 29. The position detection signal F of the potentiometer 29 is inputted to one input terminal of the differential amplifier 21 of a control part 20 and a reference position signal H is inputted to the other input terminal thereof. A drive motor 12 is driven in a direction, wherein the difference between the position detection signal F and the reference position signal H becomes 0, by the control part 20.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal transfer printer, and particularly to a ribbon winding mechanism thereof.

In general, thermal transfer printers print with the recording head pressed against the recording paper, so the printing condition is easily influenced by the tension applied to the ink ribbon.

For example, if a large amount of tension is applied to the ink ribbon, the force with which the recording head presses against the recording paper decreases, resulting in thinner print or, in some cases, the ink ribbon itself may be cut. Furthermore, if the tension of the ink ribbon is low, there is a risk that the ink ribbon may shift in the vertical direction or become loose, causing the printing part of the recording head and the ink ribbon to no longer correspond, resulting in a risk of deteriorating print quality. There is.

Therefore, in the past, methods as shown in FIGS. 6 and 7 have been proposed as means for solving the above problems.

That is, a winding mechanism C in which a resilient member j is interposed between a winding shaft a and a gear b is contained in a carriage e on which a ribbon cassette d is placed, and the resilient member The force from the guide rail k and gear b is transmitted to the winding shaft a by the pressing force of the recording head i. Regardless, the resilient member j acts appropriately to maintain a constant value. The speed difference between the take-up shaft a and the gear b is absorbed by the resilient member j, and the ink ribbon f is recorded without excessive force, and the recording paper wound around the platen g by the seventh dowel i is recorded. It will be printed.

However, with this device, the tension is adjusted by the firing force, so it is difficult to obtain the desired tension, and it is not possible to make fine adjustments. There was a problem in that transmission loss occurred due to member j.

SUMMARY OF THE INVENTION An object of the present invention is to solve these conventional problems and provide a thermal transfer printer that can always accurately wind up an ink ribbon at a constant tension.

. To achieve the above object, a thermal transfer printer according to the present invention includes a drive motor for winding an ink ribbon, a detection section for detecting the winding tension of the ink ribbon, and a drive motor for winding the ink ribbon, and a detection section for detecting the winding tension of the ink ribbon. A ribbon winding mechanism includes a control section that receives an emitted ink ribbon position detection signal and sends an appropriate signal to the drive motor, and the ribbon winding mechanism is connected to a carriage that reciprocates in the main scanning direction. The winding tension of the ink ribbon is kept constant.

According to the above configuration, the position detection signal detected by the detection unit is sent to the motor by the control unit as appropriate, the rotational speed is controlled, and the kite is wound while always maintaining a constant winding tension. It is possible to print desired characters, etc. without reducing the accuracy of printing quality.

Sue-shi--Medicine Hereinafter, the present invention will be explained in detail based on illustrated embodiments.

In FIG. 5, l is a thermal transfer printer, which includes a cylindrical platen 3 around which recording paper 2 is wound and which is rotated intermittently at a constant pitch by a line feed means (not shown), a carrier which reciprocates in the direction of arrow B; 7 and 5 constitute the main part.

As shown in FIGS. 1 and 2, the carriage 5 consists of a carriage body 6 and a ribbon cassette 7 attached thereto.

The ribbon cassette 7 is a supply reel 2 for the ink ribbon 11.
4, a winding wheel 25, and a plurality of rollers 10 for winding the ink ribbon 11 along a predetermined path. The supply reel 24 applies a required back tension to the ink ribbon 11 using a known tension applying mechanism (not shown) such as a spring. Take-up reel 25
has a spline-shaped hole (not shown) formed in its center,
It can be connected to the shaft of a drive motor 12, which will be described later, in a state where driving force can be transmitted. Also, ribbon cassette 7
There is an opening 2 in the center of the entire surface that allows the RAD 9 to enter the recording area.
6, an elongated hole 27 is formed at a proper position on the bottom surface to allow movement of a detection pin 14, which will be described later.

The carriage body 6 is provided with a recording head 9 that enters the opening 26 and engages with the ink ribbon 11 when the ribbon cassette is attached, and a ribbon winding mechanism 4. The ribbon winding mechanism 4 includes a drive motor 12 having a winding shaft 8 connected to a center hole of a winding wheel 25, a detecting section 13 for detecting the winding tension of the ink ribbon, and the detecting section 13.
The control section 20 receives a position detection signal F of the ink ribbon 11 emitted from the ink ribbon 11 and sends an appropriate signal to the drive motor 12.

The detection section 13 is composed of a position detection pin 14 that is engaged with the ink ribbon 11 and a potentiometer 29 that has a movable section 28 that is integrally connected. potentiometer 29
has a resilient member 15 such as a coil spring that resiliently biases the position detection pin 14 in the direction of arrow B. When the ink ribbon 11 is not wound (the ink ribbon 11
), the position detection pin 14 is pushed to the end of the elongated hole 27 in the B direction by the elastic member 15, but when the ink ribbon 11 is wound up, the tension applied to the winding is By the elastic member 15
moves in direction C against the urging force of.

While the ink ribbon 11 is being wound up, the ink ribbon 1
1 changes to a position where the tension and the biasing force of the resilient member 15 are balanced. Position detection pin 14
The displacement is determined by the position detection signal F by the potentiometer 29.
It is detected as a voltage signal.

In this embodiment, the control section 20 is composed of a differential amplifier 21, an integrator 22, and an amplifier 23, as shown in FIG. It is composed of a differential amplifier 21, an integrator 22, and an amplifier 23. The position detection signal F of the potentiometer 29 is input to one input terminal of the differential amplifier 21, and the reference position signal H is input to the other input terminal.

The reference position signal H is generated when the ink ribbon 11 is wound under a predetermined tension (the position of the position detection pin 14 at this time is taken as the reference position, and the tension at that time is called the reference tension). ) is set to a voltage signal equal to the device detection signal F constituted by the potentiometer 29.

As a result, the differential amplifier 21 calculates the difference (F-H) between the two signals.
In other words, the difference between the tension of the ink ribbon 11 at each instant and the reference tension is amplified and output.

As the differential amplifier 21, for example, an operational amplifier is used. The integrator 22 integrates the differential output of the differential amplifier 22 and outputs it to the next stage amplifier 23.
So-called Pl control is performed by this. The amplifier 23 operates differentially when the drive command signal G is input, amplifies the integrated output of the integrator 22, and applies it to the drive motor 12. The drive motor 12 is thereby slow controlled, and the control is performed by the control section 20 in a direction such that the difference between the position detection signal F and the reference position detection signal H becomes zero.

According to the above configuration, while the ink ribbon 11 is being wound up, if the tension of the ink ribbon 11 increases or decreases from the reference value for some reason, the detection unit 13 detects this, and the control unit 20 Since the drive motor 12 is controlled at a slow speed to eliminate the fluctuation, the tension of the ink ribbon is always kept at a constant reference tension.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and it goes without saying that the design can be changed without departing from the scope of the invention. For example, the detection unit 13 may be a sensor having a detection mechanism that keeps the tension constant at all times (an angle sensor, optical sensor, differential transformer, etc. may be used freely, and the drive motor may be a DC motor, a steering motor, or a differential transformer). You are free to use any of these methods.Furthermore, the control method is not particularly limited, and it is preferable to use the PWM method.

The thermal transfer printer according to the present invention has a ribbon winding mechanism 4.
includes a drive motor 12 for winding up the ink ribbon 11, a detection section 13 for detecting the winding tension of the ink ribbon 11, and a detection section 13 for detecting the winding tension of the ink ribbon 11, and a drive motor 12 for winding up the ink ribbon 11, and a detection section 13 for detecting the winding tension of the ink ribbon 11.
The control section 20 receives the position detection signal F of the ink ribbon 11 and sends an appropriate signal to the drive motor 12, so that the winding tension can be adjusted without being affected by the winding diameter of the ink ribbon 11. is automatically controlled and can be wound with a constant tension at all times, so there is no risk of deteriorating printing quality. In particular, since winding is performed by the direct drive motor 12, there is no transmission delay as in the conventional case. Furthermore, since the ribbon winding mechanism 4 is housed within the carriage 5, it is possible to achieve a reduction in size and weight, and there is a remarkable effect that the ribbon winding mechanism 4 can be manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is an enlarged plan view of main parts showing one embodiment of the present invention;
The figure is an enlarged front view of the same, Fig. 3 is an enlarged view taken along arrows (A-A) in Fig. 1, Fig. 4 is a block diagram showing the mechanism of the control section, and Fig. 5
The figure is a simplified plan view of the entire device, FIG. 6 is a simplified plan view of the entire device showing a conventional example, and FIG. 7 is an enlarged cross-sectional view of the same main part. 4... Ribbon winding mechanism, 5... Carriage 7, 11
... Ink ribbon, 12... Drive motor, 13...
- Detection section, 20... Control section, F... Position detection signal. Patent Applicant Minolta Camera Co., Ltd. Representative Patent Attorney Tsukasa Nakajima Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. A drive motor 12 for winding the ink ribbon 11;
A detection unit 13 that detects the winding tension of the ink ribbon 11, and an ink ribbon 11 emitted from the detection unit 13.
a control section 20 that receives a position detection signal F and sends an appropriate signal to the drive motor 12; and a ribbon winding mechanism 4 comprising a carriage reciprocating in the main scanning direction. 5, and is configured such that the winding tension of the ink ribbon 11 is constant.