JPH05147334A - Transfer type printer - Google Patents

Abstract

PURPOSE:To prevent an accident such as defective printing, ink-ribbon disconnection, etc., by keeping the carrying speed of an ink ribbon constant while holding the revolving torque of a ribbon wind-up roller constant. CONSTITUTION:A rotational-speed detecting mechanism detecting the rotational speed of a ribbon feed roller and a ribbon wind-up roller is installed, count values displaying the rotational speed of the ribbon feed roller and the rotational speed of the ribbon wind-up roller are stored in a storage area theta1 and a storage area theta2 respectively, a pulse period is read from a pulse period table by the rate A value of the count value of the storage area theta2 to the count value of the storage area theta1, and a stepping motor is driven by the pulses of the pulse period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer type printer that prints on paper using an ink ribbon.

[0002]

2. Description of the Related Art Generally, in a transfer type printer, an ink ribbon wound around a ribbon feeding roller is wound around a ribbon winding roller via a printing surface of a print head.

A platen is arranged opposite to the print head via an ink ribbon and a sheet of paper. The ink ribbon is conveyed in synchronization with the conveyance of the sheet by the platen, and the print head uses the conveyed ink ribbon. Print on paper.

By the way, since the platen which conveys the paper conveys the paper at a constant speed, the ink ribbon must also be conveyed at a constant speed in synchronization with the paper. There are two types of methods for carrying the ink ribbon, the first of which is to connect an ink ribbon carrying mechanism to the rotary drive system of the platen, and to reliably carry the paper without any special control. Can be synchronized. The second is that the take-up motor dedicated to the ink ribbon is incorporated in the ink ribbon transport mechanism, and the ribbon drive system including the take-up motor is not mechanically connected to the platen drive system, and thus is synchronized. So it needs to be electrically controlled.

In any case, however, the rotation speed of the ribbon take-up roller for taking up the ink ribbon is controlled to be constant, so that the ink is not wound at the winding start portion and the winding end portion of the ink ribbon. Ribbon winding speed is different. That is, the rotation torque applied to the ribbon winding roller changes.
Therefore, if the rotation torque becomes too large, the ink ribbon is forcibly conveyed, and the conveyance speed of the ink ribbon becomes higher than the conveyance speed of the paper, resulting in defective printing.

Therefore, in the conventional transfer type printer, for example, the rotary shaft of the ribbon winding roller is connected to the drive shaft via the friction plate. According to this, when a rotating torque of a predetermined torque or more is applied to the rotating shaft of the ribbon roller, the drive shaft idles due to the friction plate, and the rotational drive of the ribbon take-up roller is delayed by that moment so that no more rotating torque is applied. I chose

[0007]

However, the torque of the ribbon take-up roller cannot be made constant due to the difference between the static friction and the operating friction in both the above-mentioned example and the friction plate, and the ink ribbon transport speed is sometimes increased. However, there is a problem in that there is a possibility that the print speed becomes higher than the sheet conveyance speed and printing failure may occur. Further, when the friction plate is worn out, the torque of the drive shaft idling increases and a large rotational torque is applied to the ribbon winding roller, which may cause an accident such as ink ribbon breakage.

Therefore, according to the present invention, the feeding speed of the ink ribbon can be kept constant and the rotation torque of the ribbon winding roller can be kept constant, so that accidents such as defective printing and ink ribbon breakage can be prevented. It is an object of the present invention to provide a transfer type printer capable of performing the above.

[0009]

The invention according to claim 1 is
A ribbon feed roller and a ribbon take-up roller are provided, and an ink ribbon stretched from the ribbon feed roller to the ribbon take-up roller via the print surface of the print head is used to perform printing on a predetermined paper by the print head. In the transfer type printer, a motor for driving the ribbon take-up roller to rotate, a feed rotational speed detection means for detecting the rotational speed of the ribbon feed roller, and a take-up rotational speed detection means for detecting the rotational speed of the ribbon take-up roller, A rotation speed ratio calculating means for calculating a ratio between the rotation speed detected by the feed rotation speed detecting means and the rotation speed detected by the winding rotation speed detecting means, and the rotation speed calculated by the rotation speed ratio calculating means. Motor control means for controlling the rotation speed of the motor according to the ratio is provided.

According to a second aspect of the present invention, an ink ribbon provided with a ribbon feed roller and a ribbon take-up roller is stretched from the ribbon feed roller to the ribbon take-up roller via the printing surface of the print head. In a transfer type printer that prints on a predetermined paper by a print head, a DC motor that rotationally drives a ribbon winding roller, and a feed rotation speed detection unit that detects a rotation speed of the ribbon feed roller,
Winding rotation speed detection means for detecting the rotation speed of the ribbon winding roller, and rotation speed for calculating the ratio of the rotation speed detected by the feed rotation speed detection means to the rotation speed detected by the winding rotation speed detection means. Ratio calculation means, DC motor control means for controlling the rotation speed of the DC motor according to the rotation speed ratio calculated by this rotation speed ratio calculation means, and winding rotation speed detection means after control by this DC motor control means. The rotation speed comparison means for comparing the rotation speed detected by the rotation speed comparison means with the proper rotation speed of the DC motor set in advance according to the ratio of the rotation speeds calculated by the rotation speed ratio calculation means, and the rotation speed comparison means. Based on the result of the comparison, there is provided a rotation speed correction means for controlling the rotation speed of the DC motor so that the rotation speed of the ribbon winding roller becomes an appropriate rotation speed. Those were.

[0011]

In the present invention having such a structure, the rotation speed of the ribbon feed roller is detected by the feed rotation speed detecting means, and the rotation speed of the ribbon winding roller is detected by the winding rotation speed detecting means. A ratio between the rotation speed of the ribbon feed roller and the rotation speed of the ribbon take-up roller detected by the rotation speed ratio calculation means is calculated. The motor control means controls the rotation speed of the motor that rotationally drives the ribbon take-up roller according to the rotation speed ratio calculated by the rotation speed ratio calculation means.

Further, particularly when the ribbon winding roller is driven to rotate by the DC motor, the DC motor control means controls the rotation speed of the DC motor in accordance with the rotation speed ratio calculated by the rotation speed ratio calculation means. To be done. After this control, the rotation speed detected by the winding rotation speed detection means and the proper rotation speed of the DC motor set in advance according to the ratio of the rotation speeds calculated by the rotation speed ratio calculation means are the rotation speed comparison means. Compared by Based on the result of the comparison made by the rotation speed comparison means, the rotation speed correction means controls the rotation speed of the DC motor so that the rotation speed of the ribbon winding roller becomes an appropriate rotation speed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing a schematic structure of a thermal head 1 and an ink ribbon 2 of a transfer printer to which the present invention is applied. The ink ribbon 2 is wound around a ribbon feed roller 3 and the ribbon feed roller 3 is used. The roller 3 is wound around the ribbon winding roller 5 via the first auxiliary roller 4a, the thermal head 1, and the second auxiliary roller 4b. A back tension is applied to the ribbon feeding roller 3 to prevent loosening. Further, a platen 7 is arranged to face the thermal head 1 with the ink ribbon 2 and the paper 6 interposed therebetween.

The ribbon feed roller 3 and the ribbon take-up roller 5 are provided with the same rotation speed detection mechanism for detecting the rotation speed. In this rotation speed detecting mechanism, as shown in FIG. 2, the rotation shaft 3a of the ribbon feed roller 3 (the rotation shaft 5a of the ribbon winding roller 5) has a first disk member 8a (second disk member). 8
b) is connected, a plurality of circular slits are formed along the outer circumference of the first disc member 8a (second disc member 8b), and the ribbon feed side sensor 9a which is a transmission type optical sensor is formed. In the (ribbon winding side sensor 9b), the optical path from the light emitting portion to the light receiving portion is the first disk member 8a.
The plurality of slits formed in the (second disc member 8b) are provided so as to traverse the rotating orbits. FIG. 3 shows a block diagram of a circuit configuration of a main part of this transfer printer.

Reference numeral 11 denotes a CPU (cent
ral processing unit). A ROM (read onl) in which program data for processing performed by the CPU 11 is stored
ymemory) 12, a RAM (random) in which various memory areas used when the CPU 11 performs processing are formed.
access memory) 13, a ribbon feeding side counter 14a that counts the pulses output from the ribbon feeding side sensor 9a at a preset predetermined time, and a pulse that is output from the ribbon winding side sensor 9b at the predetermined time The ribbon winding side counter 14b is connected to the CPU 11 via the system bus 15. As shown in FIG. 4, the RAM 13 has a pulse cycle table 13a in which the pulse cycle is set corresponding to the A value. The A value is a ratio of the count value of the ribbon feeding side counter 14a and the count value of the ribbon winding side counter 14b, and the pulse cycle is a setting cycle of pulses for driving a stepping motor described later.

A keyboard controller 17 for controlling the keyboard 16, a head controller 18 for controlling the thermal head 18, a paper feed motor 19 for conveying the paper, and a motor for driving the ribbon take-up roller 5 to rotate. The motor controller 21 that controls the stepping motor 20 also includes the system bus 15
It is connected to the CPU 11 via. The stepping motor 20 is adapted to start or stop rotational drive in synchronization with the paper feed motor 19 during printing.

The first disc member 8a, the ribbon feed side sensor 9a and the ribbon feed side counter 14a constitute a feed rotational speed detecting means, and the second disc member 8 is provided.
b, the ribbon winding side sensor 9b and the ribbon winding side counter 14b constitute a winding rotation speed detecting means. FIG. 5 shows the flow of the ribbon drive adjustment processing performed by the CPU 11.

First, the count value is fetched from the ribbon winding side counter 14b, and the count value is stored in the RAM.
13 is stored in the storage area θ1 formed, and the count value is fetched from the ribbon feeding side counter 14a,
The count value is stored in the storage area θ formed in the RAM 13.
Store in 2. Next, the ratio A value of the count value stored in the storage area θ2 to the count value stored in the storage area θ1 is calculated. (Rotation speed ratio calculation means)

The pulse cycle corresponding to the calculated A value is read from the pulse cycle table 13a, and the stepping motor 20 is read by the pulse of the read pulse cycle.
Drive. (Motor control means) Then, the ribbon drive adjustment processing is ended.

In this embodiment having such a structure, when the second disk member 8b and the first disk member 8a provided on the rotary shafts of the ribbon winding roller 5 and the ribbon feeding roller 3 respectively rotate, The slits formed in the second disc member 8b and the first disc member 8a respectively output pulse signals from the ribbon winding side sensor 9b and the ribbon feeding side sensor 9a.

The pulses output from the ribbon winding side sensor 9b and the ribbon feeding side sensor 9a during a predetermined time set in advance are respectively fed to the ribbon winding side counter 14.
b and the ribbon feeding side counter 9a.

The ribbon feeding side counter 1 for the count value counted by the ribbon winding side counter 14b
The count value 4a is counted, the ratio A of the count values counted by the ribbon winding side counter 14b is calculated, the pulse cycle is determined from the pulse cycle table 13a by the A value, and the stepping motor 20 uses this pulse cycle. Driven by the pulse of.

The value A is the ratio of the count value of the ribbon feeding side counter 14a to the count value of the ribbon winding side counter 14b, that is, the rotation speed of the ribbon feeding roller 3 with respect to the rotation speed of the ribbon winding roller 5, as described above. , And when this A value is the smallest,
The winding start of the ink ribbon 2 is shown, and when the A value is the largest, the winding end of the ink ribbon 2 is shown. The pulse cycle table 13a is set so that the pulse cycle increases as the A value increases, and the rotation speed of the stepping motor 20 driven by the pulse of this pulse cycle gradually decreases. ..

As described above, according to this embodiment, for the ribbon feeding roller 3 and the ribbon winding roller 5, a disk member having a plurality of slits, a sensor for detecting the slits, and a pulse output from the sensor are provided. Is provided, and the ratio of the rotational speeds of the ribbon feed roller 3 and the ribbon take-up roller 5 detected by them is calculated to calculate the pulse cycle for driving the stepping motor 20 according to the rotational speed ratio. Can be gradually increased. That is, the rotation speed of the stepping motor 20 can be reduced. Therefore, since the rotation speed of the stepping motor can be slowed down in accordance with the amount of the ink ribbon wound on the ribbon winding roller 5, the ink ribbon transport speed can be maintained constant and the ribbon winding roller rotates. The torque can be kept constant.
As a result, it is possible to prevent printing failures and accidents such as ink ribbon breakage.

Another embodiment is shown in FIGS. In this embodiment, the thermal head 1, the ink ribbon 2, the ribbon feed roller 3, the first auxiliary roller 4a, the second auxiliary roller 4a, which is the print head shown in FIGS.
Auxiliary roller 4b, ribbon winding roller 5, paper 6, platen 7, first disk member 8a, second disk member 8b,
It has the same structure as the ribbon feeding side sensor 9a and the ribbon winding side sensor 9b.

Further, in the circuit configuration, as shown in FIG. 6, the CPU 31 and the CPU 3 which constitute the main body of the control unit.
ROM 3 in which program data for processing performed by 1 is stored
2. Areas of various memories used when the CPU 31 performs processing are formed, and further, as shown in FIG.
RAM 33, D in which the applied voltage table 33a in which the applied voltage and the appropriate rotation speed θx are set corresponding to the values is formed.
Only the C (direct current) motor 34 and the motor controller 35 are different, but the ribbon feeding side counter 14a, the ribbon winding side counter 14b, the system bus 15, the keyboard 16 and the keyboard controller 1 shown in the above-described embodiment.
7, the head controller 18, and the paper feed motor 19 all have the same configuration.

Therefore, the first disc member 8a, the ribbon feed side sensor 9a and the ribbon feed side counter 14a constitute a feed rotational speed detecting means, and the second disc member 8 is provided.
The ribbon winding side sensor 9b and the ribbon winding side counter 14b constitute a winding rotation speed detecting means.
FIG. 8 shows a flow of ribbon drive adjustment processing performed by the CPU 31.

First, the count value is fetched from the ribbon winding side counter 14b, and the count value is stored in the RAM1.
3 is stored in the storage area θ1 formed in No. 3, the count value is fetched from the ribbon feeding side counter 14a, and the count value is stored in the storage area θ2 formed in the RAM 13.
To memorize. Next, the ratio A value of the count value stored in the storage area θ1 to the count value stored in the storage area θ2 is calculated. (Rotation speed ratio calculation means)

The applied voltage corresponding to the calculated A value is read from the applied voltage table 33a, and the DC motor 34 is driven by the read applied voltage. (DC motor control means)

Next, in step 1 (ST1), the count value is fetched from the ribbon winding side counter 14b, stored in the storage area θ1 formed in the RAM 13, and stored in this storage area θ1. The count value is equal to the appropriate rotation speed θx set corresponding to the above-mentioned A value from the applied voltage table 33a, or
It is determined whether or not the count value stored in the storage area θ1 is larger than the appropriate rotation speed θx.

If the count value stored in the storage area θ1 is not equal to the proper rotation speed θx and is not larger than the proper rotation speed θx, the voltage applied to the DC motor 34 is increased by a predetermined voltage, and the process of step 1 is executed. To return to. If the count value stored in the storage area θ1 is larger than the proper rotation speed θx, the voltage applied to the DC motor 34 is lowered by a predetermined voltage, and the process returns to step 1 described above. Further, if the count value stored in the storage area θ1 is equal to the proper rotation speed θx, this ribbon drive adjustment processing is ended.

In the present embodiment having such a structure, unlike the above-described embodiment, the ratio of the count value counted by the ribbon winding side counter 14b to the count value counted by the ribbon feeding side counter 14a is A. Is calculated as a value, the applied voltage is determined from the applied voltage table 33a by the A value, and the DC motor 34 is driven by the applied voltage.

The value A is the ratio of the rotation speed of the ribbon winding roller 5 to the rotation speed of the ribbon feeding roller 3,
When the A value is the smallest value, it indicates the end of winding of the ink ribbon 2, and when the A value is the largest value,
The winding start of the ink ribbon 2 is shown. In the applied voltage table 33a, as the A value becomes smaller,
The applied voltage is set to be small, and the rotation speed of the DC motor 34 driven by this applied voltage is gradually reduced.

Further, after setting the applied voltage, the rotation speed of the ribbon winding roller 5 is detected again, and it is judged whether or not this rotation speed is equal to the proper rotation speed θx set corresponding to the A value. If they are not equal to each other, the applied voltage is corrected to be lowered or raised to be equal. As a result, the DC motor 34 is driven at a predetermined rotation speed. Thus, according to this embodiment, the DC
Also in the motor 34, the same effect as that of the above-described embodiment can be obtained.

[0036]

As described in detail above, according to the present invention,
It is possible to provide a transfer type printer that can maintain the ink ribbon conveyance speed constant and the rotation torque of the ribbon take-up roller constant, thus preventing printing failures and accidents such as ink ribbon breakage. ..

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a thermal head and an ink ribbon according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a rotation speed detection mechanism of the embodiment.

FIG. 3 is a block diagram showing a circuit configuration of a main part of the embodiment.

FIG. 4 is a diagram showing a configuration of a pulse cycle table of the same embodiment.

FIG. 5 is a diagram showing a flow of ribbon drive adjustment processing of the embodiment.

FIG. 6 is a block diagram showing a circuit configuration of a main part of another embodiment.

FIG. 7 is a diagram showing a configuration of an applied voltage table of the same embodiment.

FIG. 8 is a diagram showing a flow of ribbon drive adjustment processing of the embodiment.

[Explanation of symbols]

2 ... Ink ribbon, 3 ... Ribbon feeding roller, 5 ... Ribbon winding roller, 8a (8b) ... First (second) disk member, 9a (9b) ... Ribbon feeding side sensor (ribbon winding side sensor), 11 ... CPU, 13a ... Pulse period table, 14a (14b) ... Ribbon feeding side counter (ribbon winding side counter), 20 ... Stepping motor, 33
a ... Applied voltage table, 34 ... DC motor.

Claims (2)

[Claims] 1. A print head comprising: a ribbon feed roller and a ribbon take-up roller, wherein an ink ribbon stretched from the ribbon feed roller to the ribbon take-up roller via a print surface of the print head is used. In a transfer type printer for printing on a predetermined sheet by means of a motor, the ribbon winding roller is driven to rotate, a feed rotation speed detecting means for detecting a rotation speed of the ribbon feeding roller, and a rotation speed of the ribbon winding roller. Winding speed detection means for detecting, the rotation speed ratio calculation means for calculating the ratio of the rotation speed detected by the feed rotation speed detection means and the rotation speed detected by the winding rotation speed detection means, Motor control means for controlling the rotation speed of the motor according to the ratio of the rotation speeds calculated by the rotation speed ratio calculation means is provided. Transfer printer. 2. A print head comprising: a ribbon feed roller and a ribbon take-up roller, wherein an ink ribbon stretched from the ribbon feed roller to the ribbon take-up roller via a print surface of the print head is used. In a transfer type printer for printing on a predetermined sheet by means of a DC motor for rotating the ribbon winding roller, and a feed rotation speed detecting means for detecting the rotation speed of the ribbon feed roller,
A winding rotation speed detecting means for detecting the rotation speed of the ribbon winding roller, and a ratio between the rotation speed detected by the feed rotation speed detecting means and the rotation speed detected by the winding rotation speed detecting means are calculated. Rotating speed ratio calculating means, a DC motor controlling means for controlling the rotating speed of the DC motor according to the ratio of the rotating speeds calculated by the rotating speed ratio calculating means, and the winding after the control by the DC motor controlling means. And a rotation speed comparison means for comparing the rotation speed detected by the rotation speed detection means with an appropriate rotation speed of the DC motor set in advance according to the ratio of the rotation speeds calculated by the rotation speed ratio calculation means. A rotation of the DC motor so that the rotation speed of the ribbon take-up roller becomes the proper rotation speed based on the result of the comparison by the rotation speed comparison means. Transfer type printer is characterized by providing a rotational speed correction means for controlling a degree.