JPH0321479A - Thermal transfer printer - Google Patents

Abstract

PURPOSE:To eliminate a relative positional shift between an ink sheet and image receiving paper to improve a printing quality by setting an ink sheet feed amount in what is called n-tuple mode recording method to be 1/n of an image receiving paper feed amount. CONSTITUTION:A drive stepping motor 12 for an ink sheet feed roller 10 is provided with a control part common to a drive stepping motor 4 for an image receiving paper holding drum 2, rotated by pulses supplied from a driver circuit 6, and actuated based on a reference clock signal issued from a controller 7. The respective set values of rotation drive angles for the respective motors, a reduction ratio, a drum diameter, and a roller diameter at this time are set so that image receiving paper 1 is fed by one dot pitch on one or more reference clock signals and, meanwhile, an ink sheet 8 is fed by 1/n dot pitch on the same number of reference clock signals. In addition, before the completion of the action of the ink sheet 8 and the image receiving paper 1 which are fed stepwise, a thermal head 3 is applied with a printing signal. Printing is conducted after the action is completely stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermal transfer printer in which recording is performed by moving an ink sheet that can be printed multiple times at a predetermined feeding speed. (Conventional technology) A thermal transfer printer uses an ink sheet coated with heat-melting or heat-sublimating ink, which is superimposed on an image-receiving paper and moved at a predetermined speed, to create a thermal pattern corresponding to image recording information. Recording is performed by selectively transferring ink from the ink sheet using a thermal head that generates .

In recent years, in this thermal transfer printer, an ink sheet that can be printed multiple times is used, and the feeding speed of the ink sheet is set to 1/n (n is a positive number larger than 1) relative to the feeding speed of the image receiving paper. A so-called n-times mode recording method, which aims to reduce running costs, has been proposed in Japanese Patent Publication No. 62-58917. According to such an n-times mode recording method, ink sheets can be used at high density without complicating the apparatus, and waste of ink sheets can be prevented. Normal image recording information has an image density distribution from halftone density to maximum density. Therefore, the ink sheet has an ink composition that can reproduce the maximum image density portion, so that image printing can be performed at all times. In the above-mentioned n-times mode recording method, the ink sheet feeding speed is 1/n of the normal feeding speed, that is, 1/n of the image-receiving paper feeding speed. The maximum image density part is made reproducible. (Problem to be Solved by the Invention) However, in the image-receiving paper conveyance drive mechanism and the ink sheet conveyance drive mechanism, it is necessary to keep the respective feed speeds of the ink sheet and the image-receiver paper constant and to accurately match the feed speeds of both. Even if these driving sources are combined into one, it is difficult to maintain the voltage at n due to the effects of load fluctuations. As a result, a relative positional shift occurs between the ink sheet and the image-receiving paper, and the ink is not transferred well from the ink sheet side to the image-receiving paper side, which may cause deformation of each dot making up the image. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a thermal transfer printer that can eliminate relative positional deviation between an ink sheet and an image receiving paper in the so-called n-times mode recording method and improve printing quality. .

(Means to Solve the Problem) In order to achieve the above object, the invention described in claim 1 is capable of printing multiple times in a fixed direction on an image receiving paper that is moved in a fixed direction. In a thermal transfer printer, recording is performed by overlapping ink sheets and selectively transferring the ink on the ink sheets using a thermal head that generates a thermal pattern according to image recording information. The feed amount is
It has a configuration in which the feeding amount of the receiving paper is set to 1/n.

The invention described in claim 2 provides an ink sheet that can be printed multiple times and is transported in a certain direction by a predetermined transport drive mechanism on an image receiving paper that is transported in a certain direction by a predetermined transport drive mechanism. In a thermal transfer printer that performs recording by selectively transferring ink on the ink sheet using a thermal head that generates a thermal pattern according to image recording information,
The feed amount of the ink sheet is set to 1/n with respect to the feed amount of the image-receiving paper, and the transport drive mechanisms for the image-receiver paper and the ink sheet are set to the same reference clock. A common controller is attached so as to perform a transfer operation based on a signal.

The invention described in claim 3 superimposes an ink sheet that can be printed multiple times that is transported in a certain direction on an image receiving paper that is transported in a certain direction, and forms a thermal pattern according to image recording information. In a thermal transfer printer that performs recording by selectively transferring ink on the ink sheet using a generated thermal head, the amount of feeding of the ink sheet is 1 times the amount of feeding of the image receiving paper.
/n, the ink sheet feed and image receiving paper feed are operated in steps, and an electric current is applied to the thermal head before these operations are completed.

(Function) In the means having the structure described in claim 1,
The ink sheet is reliably fed by a feed distance of 1/n relative to the image receiving paper. In the means having the structure described in claim 2, the same reference clock signal is issued from a common controller to each transport drive mechanism for the receiving paper and the ink sheet, and the ink sheet is moved at a rate of 1/n relative to the receiving paper. The amount of feed is ensured. In the means having the configuration described in claim 3,
The ink sheet is now reliably fed by a feed amount of 1/n against the image receiving paper, and the receiving layer (
This prevents dot decomposition as well as roughness on the surface of the print area (printing area), allowing clearer printing and reducing total printing time.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings. In FIG. 1, the image-receiving paper 1 is set by being placed on the outer peripheral conveying surface of the image-receiving paper holding drum 2, and is being fed in a certain direction at a constant speed Vp. A thermal head 3 is disposed so as to face the outer circumferential conveying surface of the image-receiving paper holding drum 2, and a printing area is formed in a portion where the thermal head 3 and the image-receiving paper holding drum 2 face each other. A pulley 28 fixed to the support shaft of the image-receiving paper holding drum 2 receives rotational driving force from a pulley 4a fixed to the output shaft of the drive step motor 4 via the timing belt 5. The drive step motor 4 is rotationally driven in steps by pulsed power supplied from a driver circuit 6, and the driver circuit 6 is further operated based on a reference clock signal for control issued from a controller 7. There is. The thermal head 3 generates a thermal pattern according to image information, and is disposed such that an ink sheet 8 is sandwiched between the thermal head 3 and the image receiving paper holding drum 2. This ink sheet is fed in the same direction as the image-receiving paper 1 at a constant speed Vi, and the speed of the image-receiving paper 1 and the ink sheet 8 is determined to be V p /V i > 1 (n-fold mode). For example, the ink sheet has 2
A layered structure is used. The ink sheet 8 is pulled out from the supply reel 8a and taken up by the take-up reel 8b, and the middle portion thereof is gripped by the nip between the ink sheet feed roller 10 and the pressure roller 11. Rotational driving force is transmitted to the support shaft of the ink sheet feed roller 10 from a drive step motor 12 via a timing belt 13. The drive step motor 12 is provided with a common control unit as the drive step motor 4 that drives the image receiving paper holding drum 2.
That is, the drive step motor 12 is rotationally driven by electric power supplied in pulse form from the driver circuit 6, and the driver circuit 6 is operated based on a reference clock signal for control issued from the controller 7. At this time, each set value of the rotational drive angle, reduction ratio, drum diameter, and roller diameter of each of the motors is set such that the image receiving paper 1 is fed by an amount of 1 dot pitch by one or more reference clock signals, and the ink sheet 8 is 1/by the same number of reference clock signals.
Each is set to be sent by an amount of n dot pitch. Also, during printing, the settings are set so that before the ink sheet 8 and image receiving paper 1 that are conveyed in steps in a stepwise manner finish their operations during printing, a voltage is applied to the thermal head 3, and printing is performed after they have completely stopped. It has been done. In such an embodiment: the respective feed distances of the ink sheet 8 and the receiver paper 1 are directly controlled and are transported in steps, so that the ink sheet 8 is precisely 1/n with respect to the receiver paper 1. The ink sheet 8 and image receiving paper 1 are fed by a feed amount of The image receiving paper 1 is not misaligned relative to the image receiving paper 1, and the next ink sheet 8 and image receiving paper 1 are conveyed after the printing heat applied to the thermal head 3 has cooled down after printing. By preventing the ink from being transported in a softened state, it is possible to prevent surface roughness of the receiving layer section (printing section) and a decrease in resolution in the transport direction due to the connection of dots, and to ensure good printing. Become. As a result, the ink is transferred well from the ink sheet 8 side to the receiver paper 1 side, and deformation of each dot constituting the image is prevented. In the embodiment shown in FIG. 2, in which the same components as those in the embodiment shown in FIG. A driving force transmitting means is provided for connecting both transport drive mechanisms so that the mechanisms perform a stepwise transport operation in synchronization. That is, pulleys 22 and 23 with diameters z2 and 2 are coaxially fixed to the support shaft of the image receiving paper holding drum 2 having a drum diameter of radius r4, and
The pulley 22 with a diameter z2 is connected to a drive step motor 24.
It is connected via a timing belt 26 to a pulley 25 having a diameter z1 which is fixed to the output shaft of the engine 1 so as to be capable of transmitting rotational driving force. On the other hand, the pulley 23 having a diameter Z is connected to the ink sheet feeding roller 2 having a roller diameter of a radius r2.
It is connected by a timing belt 29 to a pulley 28 having a diameter z4 fixed to a support shaft 7 so as to be capable of transmitting rotational driving force. At this time, each drum diameter and roller diameter are set so as to satisfy the following relationship with respect to the rotation angle θ of the drive step motor 24.

36Q Z, Z. ? n r, Xz. In this case, in order to obtain a 1-dot pitch (receiving paper feeding amount) for the rotation angle θ of the drive step motor 24, the above (1) is required.
In the equation, the values of 2, 2, and r■ may be determined so that the value of A corresponds to one dot pitch. In addition, during printing, the settings are set so that before the operation of the ink sheet 8 and image receiving paper 1, which are transferred in steps according to the above settings, is completed, a voltage is applied to the thermal head 3, and printing is performed after the thermal head 3 has completely stopped. has been done.

Note that the drive motor in each of the above embodiments can be operated intermittently or continuously. Particularly when the transfer time of ink from the ink sheet is slow, good printing operation can be achieved by executing intermittent operation control. In addition, if the ink transfer timing and the feeding timing deviate, a good printing operation can be performed by shifting the control timing by the deviated time. Furthermore, the resolution is set to 1/in (i is an integer) for the feed amount 1/n.
It is also possible to obtain a feed amount of n.

(Effect of the invention) As stated above, the invention stated in claim 1 is:
In order to ensure that the ink sheet is fed without misalignment with respect to the receiving paper, the feeding amount of the ink sheet is set to 1/n with respect to the feeding amount of the receiving paper. In the n-time mode recording method, it is possible to eliminate misalignment between the ink sheet and the image-receiving paper, to ensure good ink transfer from the ink sheet side to the image-receiving paper side, and to prevent deformation of each dot that makes up the image. It is possible to prevent this and improve printing quality.

The invention described in claim 2 is such that the feeding amount of the ink sheet is adjusted relative to the feeding amount of the image receiving paper so that the ink sheet is reliably fed without causing any positional deviation with respect to the image receiving paper. 1/n, and a common controller that emits the same reference clock signal is attached to each transport drive mechanism for the image receiving paper and the ink sheet, so that similar to the effect according to claim 1, the so-called In the n-time mode recording method, it is possible to eliminate misalignment between the ink sheet and the image-receiving paper, to ensure good ink transfer from the ink sheet side to the image-receiving paper side, and to prevent deformation of each dot making up the image. It is possible to prevent this and improve printing quality. The invention described in claim 3 conveys the ink sheet and the image-receiving paper in a stepwise manner, so that the ink sheet and the image-receiving paper are conveyed in a stepwise manner so that the ink sheet is reliably fed without causing any positional deviation with respect to the image-receiving paper. The feed amount is set to 1/n with respect to the feed amount of the image receiving paper, and during printing, the ink sheet and the image receiving paper that are transported in steps according to the above settings are applied to the thermal head before the operation of the image receiving paper is completed. Since the printing is performed after the ink sheet is completely stopped, the positional deviation between the ink sheet and the image receiving paper is eliminated in the so-called n-times mode recording method, and the ink sheet is Ink transfer from the side to the image-receiving paper side can be performed well, and it is possible to prevent deformation of each dot constituting the image and improve printing quality.

[Brief explanation of drawings]

FIG. 1 is an explanatory side view showing a thermal transfer printer according to one embodiment of the present invention, and FIG. 2 is an explanatory side view showing a thermal transfer printer according to another embodiment of the invention. 1... Image receiving paper 2... Image receiving paper holding drum 3...
Thermal head 4, 12... Drive step motor 7... Controller 8... Ink sheet 10
．． 11... Ink sheet feed roller

Claims (1)

[Claims] 1. An ink sheet that can be printed multiple times and is transported in a certain direction is superimposed on an image receiving paper that is transported in a certain direction,
In a thermal transfer printer that performs recording by selectively transferring the ink on the ink sheet using a thermal head that generates a thermal pattern according to image recording information, the feeding amount of the ink sheet is determined by the amount of paper being fed. A thermal transfer printer characterized in that the feed amount is set to 1/n. 2. An ink sheet that can be printed multiple times and is transported in a fixed direction by a predetermined transport drive mechanism is superimposed on the image receiving paper that is transported in a fixed direction by a predetermined transport drive mechanism, and heat is applied according to the image recording information. In a thermal transfer printer that performs recording by selectively transferring ink on the ink sheet using a thermal head that generates a pattern, the amount of feed of the ink sheet is 1/1 of the amount of feed of the image receiving paper. n, and a common controller is attached to each of the image receiving paper and ink sheet transport drive mechanisms so that both transport drive mechanisms perform transport operations based on the same reference clock signal. A thermal transfer printer characterized by: 3. An ink sheet that can be printed multiple times and is transported in a certain direction is superimposed on an image receiving paper that is transported in a certain direction,
In a thermal transfer printer that performs recording by selectively transferring the ink on the ink sheet using a thermal head that generates a thermal pattern according to image recording information, the feeding amount of the ink sheet is determined by the amount of paper being fed. A thermal transfer type that is set to 1/n of the feeding amount, operates ink sheet feeding and image receiving paper feeding in steps, and applies a printing signal to the thermal head before this operation is completed. printer.