JP2910896B2 - Thermal transfer printing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer printing apparatus using a take-up type ink ribbon, and more particularly to an apparatus capable of precisely controlling a take-up speed of an ink ribbon to a desired level. is there.

[0002]

2. Description of the Related Art As a thermal transfer printing apparatus generally used today, there is an apparatus which drives a take-up reel of an ink ribbon by a motor whose rotation speed can be arbitrarily variably controlled. In this type of thermal transfer printing apparatus used for automatic ticketing, ticketing machines, etc. of air tickets, for example, as shown in FIG. Is set to be wound on the take-up reel 7 while passing between the thermal head 5 and the platen 6. The take-up reel 7 is rotationally driven via an endless belt 8 by a take-up drive motor M such as a pulse motor capable of arbitrarily variably controlling a rotational displacement amount per unit time, that is, a rotational speed. The ink ribbon 2 is wound up in accordance with the progress of printing. For example, the friction clutch CL mounted coaxially with the take-up reel 7 normally gives a rotational drive force from the take-up drive motor M to the take-up reel 7 by frictional force.
When the motor M applies an excessive load exceeding a predetermined value to the take-up reel 7 at the start of rotation of the motor M, that is, when an excessive rotational driving force is applied, the motor M slips on the take-up reel 7 and acts to prevent this. Thereby, the winding force of the winding reel 7 is optimized. The delivery reel 3 performs delivery of the ink ribbon 2 following the winding operation of the ink ribbon 2 by the take-up reel 7 or following the feeding operation of the ink ribbon 2 by the platen 6. It is.

More specifically, a sheet S to be printed is fed between the ink ribbon 2 and the platen 6 by a feed roller (not shown). In response, the thermal head 5 is moved from the standby position to a printing position where the ink ribbon 2 is brought into contact with the printing target sheet S, and thereafter, the ink of the ink ribbon 2 is applied to the printing target sheet S. The desired information is printed on the printing target sheet S by thermal transfer. At this time, by rotating the platen 6 in the direction of the arrow, the sheet S to be printed is fed forward, and the ink ribbon 2 corresponding to the feed of the print sheet S is also sent. Usually, the feeding speed of the ink ribbon 2 by the platen 6 is controlled by the take-up reel 7 according to the rotation of the take-up driving motor MF.
Is set to be lower than the winding speed of the ink ribbon 2 due to the above. Therefore, while the thermal head 5 is at the printing position, the take-up drive motor MF is rotated at a preset speed, but the take-up reel 7 is rotated by the rotation of the platen 6 by the slipping action of the friction clutch CL. The ink ribbon 2 is wound up by the feed amount (clockwise in FIG. 1).

When printing on the printing target sheet S is completed, the thermal head 5 retreats to the initial standby position where the thermal head 5 is separated from the ink ribbon 2, and the winding drive motor M which has been rotating at the preset speed until then. Is stopped, whereby the winding operation of the ink ribbon 2 by the winding reel 7 is also stopped. At the end of printing, as the thermal head 5 retreats to the standby position, the ink ribbon 2 that has been pushed by the thermal head 5 has a considerable slack.

Further, in the related art, at the same time when printing on the sheet S to be printed is completed, the rotation of the motor M that has been rotating is stopped immediately, and the winding reel 7 winds the ink ribbon 2. The operation is stopped immediately. In this way, the winding operation of the ink ribbon 2 is instantaneously stopped at the end of printing, so that the thermal head 5
The slack caused by the retreat remains without being eliminated. In addition, the delivery reel 3, which rotates following the take-up reel 7, has a large diameter, particularly,
Even after the take-up operation by the take-up reel 7 is stopped, the take-up reel 7 continues to rotate due to its own inertia force. Thus, the slack of the ink ribbon 2 generated by the retreat of the thermal head 5 described above is added to the slack generated by the rotation of the delivery reel 3 due to the inertial force. There will be a large amount of slack in contact. The ink ribbon 2 slackened in this way causes the platen 6
It may not be able to be separated while adhering. When the above-described printing operation is performed for the next sheet S to be printed in the attached state, the ink ribbon 2 is complicatedly entangled around the platen 6 that rotates as the sheet S to be printed advances. Various troubles such as damage occur.

Therefore, as one method for eliminating and preventing the slack of the ink ribbon 2 generated at the end of printing as described above, the winding drive motor M is once decelerated for a predetermined time after the end of printing. The applicant has proposed a method in which the take-up reel 7 performs an additional take-up operation in a decelerated state by rotating and stopping. That is, according to this proposal, the additional winding operation eliminates the slack of the ink ribbon 2 caused by the retreat of the thermal head 5, and the additional winding operation is performed in a deceleration state. By stopping after that, the slack generated by the inertial force of the sending reel 3 is effectively prevented.

[0007]

By the way, in this type of thermal transfer printing apparatus, the ink of a new portion of the ink ribbon 2 is always transferred to the print sheet S.
That is, the ribbon take-up speed (actually, the ink ribbon 2 is taken up in the longitudinal direction thereof) so that the transfer density of the ink is not reduced as a result of the same portion of the ink being transferred to different print portions in an overlapping manner. Speed, which is proportional to the actual ribbon winding amount), must be higher than the printing speed. Therefore, conventionally, the rotation speed of the winding drive motor M is several percent faster than the printing speed when the winding radius of the ink ribbon 2 on the winding reel 7 is minimum. Such a constant rotation speed is set in advance. Thus,
The winding drive motor M is configured to be rotated at the constant rotational speed from start of use (winding start end) to end of use (winding end) of one ink ribbon 2 throughout.

However, when the take-up drive motor M is rotated at the constant rotational speed throughout the entire process, the take-up radius of the ink ribbon 2 increases with the progress of printing. , The ribbon winding speed is increased. In other words, in principle, the rotation speed of the winding drive motor M × the winding radius corresponds to the ribbon winding speed. Therefore, if the rotation speed of the winding drive motor M is constant, the winding proceeds. Thus, as the winding radius increases, the ribbon winding speed also increases.
Thus, by the time the ink ribbon 2 has been used up to its end, the winding radius increases to several times the minimum, and therefore the ribbon winding speed becomes extremely faster than the printing speed. This leads to a large use loss (wasteful use) of the ink ribbon 2.

In particular, when the ribbon take-up speed is extremely high, an additional take-up operation after printing is completed to eliminate or prevent the slack of the ink ribbon 2 as proposed by the present applicant. Is performed, the amount of the ink ribbon 2 to be additionally wound up becomes unnecessarily large. This results in a large use loss of the ink ribbon 2.
Further, when the ribbon winding speed is extremely high, the condition under which the friction clutch CL slips as described above changes, and as a result, the function of stably optimizing the winding force of the winding reel is greatly impaired. It will also be.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a thermal transfer printing apparatus capable of controlling the winding speed of an ink ribbon to a desired level accurately.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a thermal transfer printing apparatus according to the present invention comprises a ribbon sending device.
From the step (3), it is wound by the ribbon winding means (7)
The raised ink ribbon (2) and the ink ribbon
Desired information for the sheet to be printed (S) by (2)
A print head (5) for printing an image and a print head (5).
Winding the ink ribbon (2) according to the progress of printing
To take up the winding means (7).
And an ink ribbon (2) at the end of printing.
In order to eliminate the slack, follow up by the winding means (7).
A thermal transfer printing apparatus for performing additional winding, wherein a winding hand is provided.
The winding progress of the ink ribbon (2) in the step (7)
Winding progress detecting means (10, 12, 13,
S1, S2, S3, S4, 18, 20) and detecting means
(10, 12, 13, S1, S2, S3, S4, 18,
According to the change in winding progress detected by 20)
To change and control the rotation speed of the winding drive motor (M)
Motor control means (14, 16);
(S1, S2, S3, S4) are half of the winding means (7).
A plurality of lights provided at predetermined intervals along the diameter extension line (R)
Sensors (S1, S2, S3, S4).
Based on the output signal of the optical sensor (S1, S2, S3, S4)
Of the ink ribbon (2) in the winding means (7).
It is characterized by detecting a change in winding radius
You.

[0012]

The winding progress detecting means (10, 12, 13, S
1, S2, S3, S4, 18, 20) sequentially detect the winding progress of the ink ribbon (2) in the ribbon winding means (7). The motor control means (14, 16) includes the detection means (10, 12, 13, S1, S2, S3, S3).
The rotation speed of the winding drive motor (M) for driving the winding means (7) is changed and controlled in accordance with the change in the winding progress detected by (4, 18, 20). That is, the motor control means (14, 16) sets the rotation speed of the winding drive motor (M) to the maximum when the winding progress is minimum, and thereafter, as the winding progress increases, the winding control proceeds. Control is performed to sequentially lower the rotation speed of the take-off drive motor (M).

By such control, the ribbon take-up speed can be made substantially constant at a desired level, for example, several percent higher than the print speed, from start to finish of the ink ribbon (2). . In particular, even when the winding progress reaches the maximum value, that is, near the maximum winding radius, the ribbon winding speed is maintained at the same speed as at the minimum winding radius. Therefore,
In particular, when the additional winding by the winding means (7) is performed in order to eliminate the slack of the ink ribbon (2) at the end of printing of the printing target sheet (S), the ink ribbon to be additionally wound The amount of (2) can be suppressed to the minimum necessary. As a result, the use loss of the ink ribbon (2) can be minimized.

[0014]

[0015]And windingProgress detection means (S1, S
2, S3, S4, 18, 20)Ribbon winding means
(7) are provided at predetermined intervals along a radius extension line (R).
For example, a plurality of light sensors of a transmissive type or a reflective type
(S1, S2, S3, S4)It is.this
IfpluralOutput of optical sensors (S1, S2, S3, S4)
Based on the force signalRibbon winding meansB in (7)
Change of winding diameter by ink ribbon (2)Winding progress
Detect as a degree. In addition, take up the ribbon at the end of printing
Additional winding is performed by means (7), and
Ink to be taken up when eliminating slack in Bonn (2)
The amount of the ribbon (2) depends on the winding diameter of the ink ribbon (2).
Rewind to the minimum necessary.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a front view illustrating a configuration example of a thermal transfer printing apparatus according to an embodiment of the present invention. As above, first,
The ink ribbon 2 is set so as to be wound around a take-up reel 7 from a delivery reel 3 through a plurality of guide rollers 4, passing between a thermal head 5 and a platen 6. The solid line in FIG. 1 shows a state in which the winding of the ink ribbon 2 by the winding reel 7 has not substantially proceeded yet. Therefore, in this state, the take-up radius of the take-up reel 7 is minimum. In the illustrated example, the thermal head 5 is at a standby position separated from the ink ribbon 2 by a predetermined distance.

A printing sheet S such as paper is fed between the ink ribbon 2 and the platen 6 in the direction of the arrow. When such feeding of the printing sheet S is detected, the thermal head 5 moves from the standby position to a printing position where the ink ribbon 2 is brought into contact with the printing sheet S. In this manner, by selectively driving the dot matrix, the thermal head 5 transfers the ink of the ink ribbon 2 to the printing target sheet S by heating, and prints desired information on the printing target sheet S. In accordance with the progress of printing, the platen 6 rotates in the direction of the arrow, and by this rotation, the printing target sheet S is sent forward, and the ink ribbon corresponding to the feeding of the printing sheet S via the printing sheet S. A feed of 2 is also performed. Usually, the feeding speed of the ink ribbon 2 by the platen 6 is set lower than the winding speed of the ink ribbon 2 by the winding drive motor M.

Therefore, while the thermal head 5 is at the printing position, the take-up drive motor M is rotated at a preset speed, but the take-up reel 7 is rotated by the friction action of the friction clutch CL. 6
The ink ribbon 2 is wound up by the amount of rotation caused by the rotation of (1) (clockwise direction in FIG. 1). The ink ribbon 2 is sent to the take-up reel 7 side. Winding drive motor M
Thus, the take-up reel 7 is driven to rotate via the endless belt 8 to take up the ink ribbon 2. For example, the friction clutch CL mounted coaxially with the take-up reel 7 normally gives a rotational drive force from the take-up drive motor M to the take-up reel 7 by frictional force. When the motor M
When the excessive rotational driving force is applied from the above, or when the thermal head 5 is at the printing position as described above, the slippage occurs with respect to the take-up reel 7, thereby reducing the take-up force by the take-up reel 7. Has a function to optimize.

When printing on the printing target sheet S is completed, the thermal head 5 retreats to the initial standby position, and the printed printing target sheet S is discharged out of the apparatus. At this time, with the retreat of the thermal head 5 to the standby position,
The ink ribbon 2 that has been pushed by the thermal head 5 will have considerable slack. Therefore,
In this embodiment, in order to eliminate the slack of the ink ribbon 2 generated at the end of printing, for example, the winding drive motor M is driven at a lower speed than the rotation speed for a predetermined time after the end of printing by a computer program. The control is performed such that the rotation is decelerated and then stopped. Thus, the take-up reel 7 stops after performing additional take-up in a decelerated state. Further, since this additional winding is performed in a decelerating state, after the additional winding is performed, the take-up reel 7 does not generate a large inertial force on the delivery reel 3, and thus is relatively movable. Can stop slowly. Therefore, the occurrence of new slack of the ink ribbon 2 due to the inertial force of the delivery reel 3 is prevented. In this manner, after printing, the ink ribbon 2 can be reliably set in a slack-free state, and the printing operation on the next sheet S to be printed can be performed without any trouble. It is most preferable that the additional winding be performed by rotating the winding drive motor M in a plurality of stages or while gradually reducing the speed linearly.

Further, as the most important feature, this embodiment is configured so that the ink ribbon 2 can be used most effectively without waste. That is, in this embodiment, the rotation speed of the winding drive motor M is changed and controlled in accordance with the change in the winding progress of the ink ribbon 2, whereby the ink ribbons 2 can be used up (winding start end). The actual winding speed of the ink ribbon 2 is set to be several percent higher than the printing speed throughout the entire period from the end of use to the end of use (end of winding). As a novel arrangement for achieving this object, in this embodiment a known distance sensor 10 is provided at a location adjacent to the outer periphery of the take-up reel 7, preferably using an infrared measuring beam or a laser measuring beam. ing.

That is, in this case, the measurement beam emitted in the radial direction from the distance sensor 10 toward the take-up reel 7 is reflected by the surface of the ink ribbon 2 wound on the take-up reel 7 and is reflected by the sensor. The measurement beam reciprocating time until returning to the position 10 is measured, and based on this measurement time, the distance from the distance sensor 10 to the ink ribbon 2 on the take-up reel 7 (hereinafter referred to as a sensor ribbon distance for convenience). Is detected. The current winding radius is detected from the sensor ribbon distance detected in this manner. The operation of detecting the sensor ribbon distance and the winding radius in this manner, as described later with reference to FIG. In addition, the ribbon winding speed by the winding reel 7 (therefore, the ribbon winding amount proportional to the ribbon winding speed) can be appropriately controlled to a desired level.

FIG. 2 is a block diagram illustrating a main configuration for controlling the ribbon winding speed to a desired level as described above in the embodiment of FIG. When printing on the printing target sheet S is started and the winding reel 7 starts winding the ink ribbon 2, the distance sensor 10 is started, and the output signal of the distance sensor 10 is instantaneously output to the distance detecting circuit 12. Given to. The distance detection circuit 12 detects the sensor ribbon distance based on the output signal DS. The take-up radius detection circuit 13 detects the take-up radius of the take-up reel 7 by subtracting the sensor ribbon distance thus detected from a predetermined reference sensor ribbon distance. Thus, in the motor rotation speed determination circuit 14, based on the detected winding radius,
The rotational speed of the take-up drive motor M is determined so that the ribbon take-up speed by the take-up reel 7 is several percent higher than the printing speed. It should be noted that such a determination of the rotational speed may be performed, for example, by referring to a table stored in a memory in advance, or may be performed by an operation using predetermined reference data. Is also good.

The rotation speed instruction signal MV for instructing the determined rotation speed is supplied to the motor drive control circuit 16. The motor drive control circuit 16 controls the drive of the winding drive motor M so that the motor M rotates at a speed according to the rotation speed instruction signal MV. The above operation is continuously and repeatedly performed while the winding of the ink ribbon 2 is performed. Thus, as shown in FIG. 4A, when the winding radius is minimum (winding start end), the rotation speed of the winding drive motor M is increased so that the ribbon winding speed is always several percent higher than the printing speed. At most, thereafter, control is performed such that the rotational speed of the drive motor M decreases as the winding radius increases. As a result, the ribbon winding speed is maintained at the same speed as the minimum winding radius even when the winding radius approaches the maximum winding radius as shown by the two-dot chain line in FIG. 1, for example. Will be. Thereby, the ink ribbon 2 can be used most efficiently consistently.

In particular, when the take-up reel 7 performs additional winding in order to eliminate the slack of the ink ribbon 2 at the end of printing of the printing target sheet S as described above, the ink ribbon to be additionally wound is used. 2 can be kept to the minimum necessary. Further, since the ribbon take-up speed is constant, the slip condition of the friction clutch CL does not change, so that the take-up force of the take-up reel 7 can be optimized.

FIG. 3 shows a second embodiment of the present invention. Here, only the characteristic portions of this embodiment are extracted and shown. While the first embodiment shown in FIGS. 1 and 2 uses the distance sensor 10 to enable the winding radius to be detected every moment, in the embodiment shown in FIG. 3, the light emitting element P1 is used.
And a plurality of (four in the illustrated example) optical sensors S1 in which the light receiving elements P2 are opposed in a direction parallel to the tangent to the take-up reel
S4 are provided at predetermined intervals along the radius extension line R of the take-up reel 7, so that the degree of progress of winding on the take-up reel 7, that is, the take-up radius can be detected stepwise. I have.

More specifically, when the take-up on the take-up reel 7 is not substantially progressing and the take-up radius is near the minimum value, as shown in FIG. In all of the steps S4 to S4, the light beam from the light receiving element P1 is received by the light receiving element P2. Thereafter, as the winding radius increases, S1 →
In the order of S2 → S3 → S4, the respective optical sensors enter a state where the light beam from the light receiving element P1 is shielded by the ink ribbon 2, and outputs a signal indicating that.

In the sensor state detecting circuit 18, the optical sensor S
These optical sensors S1 to S4 are based on the outputs from S1 to S4.
The light receiving state or the light blocking state in S4 is detected. The winding radius detection circuit 20 detects an approximate current winding radius by recognizing the light-shielded optical sensors S1 to S4 based on reference data stored in advance in a memory. Thus, in the motor rotation speed determination circuit 14 similar to that of the above-described first embodiment, the ribbon winding speed by the winding reel 7 becomes several percent faster than the printing speed based on the detected winding radius. The rotation speed of the winding drive motor M is determined as described above. In addition,
Such a determination of the rotation speed may be performed with reference to a table stored in the memory in advance, as described above,
Alternatively, it may be executed by an operation using predetermined reference data.

Thus, the rotation speed instruction signal MV for instructing the determined rotation speed is supplied to the motor drive control circuit 16. The motor drive control circuit 16 controls the drive of the winding drive motor M so that the motor M rotates at a speed according to the rotation speed instruction signal MV.

The above-described operation in the second embodiment shown in FIG. 3 is repeated stepwise at predetermined time intervals while the winding of the ink ribbon 2 is performed. As a result, as shown in FIG. 4B, the rotation speed of the drive motor M gradually decreases as the winding radius increases, so that the winding speed is almost always several percent higher than the printing speed. Is performed. as a result,
For example, even when the winding radius approaches the maximum value as shown by the two-dot chain line in FIG. 3, the ribbon winding speed is maintained at substantially the same speed as at the minimum winding radius. . Therefore, the same effect as in the case of the first embodiment is realized. In this embodiment, in order to detect the winding diameter more precisely,
The number of the optical sensors may be increased, and the optical sensors may be arranged at narrower intervals. Further, the optical sensor is not limited to the light-transmitting type described above, and may be a reflective type that uses light reflected by the ink ribbon 2 wound on the take-up reel 7. In the first and second embodiments, the distance detecting circuit 12, the sensor state detecting circuit 18,
The functions of the winding radius detection circuits 13 and 20, the motor rotation speed determination circuit 16 and the motor drive control circuit 16 may be realized by a computer program.

[0030]

As described above, according to the present invention, the winding progress of the ink ribbon is sequentially detected, and the rotation speed of the winding drive motor is variably controlled in accordance with the detected change in the winding progress. Therefore, an excellent effect that the ribbon winding speed can be appropriately controlled to a predetermined level can be obtained. Therefore, in particular, the ink ribbon can be effectively used with a minimum use loss. In addition, winding
A plurality of progress detecting means are provided along the radial extension of the winding means.
The optical sensors are arranged at predetermined intervals, and
The ink wound by the winding means based on the output signal of the
Detect changes in ribbon winding diameter as winding progress
At the end of printing.
Winding to eliminate slack in the ink ribbon during printing
When you take up the ink ribbon,
Can be wound according to the winding diameter of
Can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of the internal configuration of a thermal transfer device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration for changing and controlling the rotation speed of a winding drive motor according to a change in an ink ribbon winding radius in the embodiment.

FIG. 3 is a block diagram showing only a characteristic portion of the second embodiment of the present invention;

FIG. 4 is a graph for explaining the operation of the first embodiment shown in FIGS. 1 and 2 and the operation of the second embodiment shown in FIG. 3;

[Explanation of symbols]

 2 Ink ribbon 5 Thermal head 7 Take-up reel 10 Distance sensor 12 Distance detection circuit 13 Take-up radius detection circuit 14 Motor rotation speed determination circuit 16 Motor drive control circuit 20 Take-up radius detection circuit M Take-up drive motor S1 Optical sensor S2 Light Sensor S3 Optical sensor S4 Optical sensor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Toshinori Sudo 11-2, Hirade Industrial Park, Utsunomiya City, Tochigi Pref. Kaihei 2-175181 (JP, A) JP-A 63-145649 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B41J 31/00-35/38 B41J 17/00- 17/42

Claims (1)

(57) [Claims] 1. An ink ribbon (2) wound from a ribbon sending-out means (3) to a ribbon winding means (7), and a sheet (S) to be printed by the ink ribbon (2). Print head for printing desired information
A winding drive motor (M) for rotating the winding means (7) for winding the ink ribbon (2) in accordance with the progress of printing by the print head (5) ; Eliminates slack in the ink ribbon (2) at the end of printing
In order to perform the additional winding by the winding means (7),
A thermal transfer printing apparatus, wherein the ink ribbon (2) in the winding means (7) is provided.
Winding progress detecting means (1) for sequentially detecting the winding progress degree of
0, 12, 13, S1, S2, S3, S4, 18, 2
0), and the detection means (10, 12, 13, S1, S2, S3,
S4,18,20) in response to the detected change in the winding progress by, and a motor control means (14, 16) for changing control the rotational speed of the winding drive motor (M)
And the detection means (S1, S2, S3, S4)
At predetermined intervals along the radial extension line (R) of the connecting means (7).
A plurality of light sensors (S1, S2, S3, S4)
The plurality of optical sensors (S1, S2, S3, S4)
On the basis of the output signal of the winding means (7).
Detecting a change in a winding radius of the ink ribbon (2);
A thermal transfer printing apparatus , characterized in that: