JPH0343274A - Linear type color thermal transfer printer - Google Patents

Abstract

PURPOSE:To control the rotary speed of a motor by calculating the ratio of a signal period detected by a device for detecting the rotary speed of a motor and bar codes and comparing the calculated value with a specified reference. CONSTITUTION:A bar code detection signal (a) detected by a bar code sensor 6 is sent to a comparison mechanism 101. This mechanism 101 calculates the winding value of an ink film 5 for each drive pulse of a stepping motor 4 based on the ratio of the number of drive pulses of the stepping motor 4 to the number of detections of the bar code detection signal(a), then a reference value (b) obtained from a reference value storage part 103 is used for comparison. A signal C which represents the comparison result is sent to a motor control mechanism 102. The motor control mechanism 102 determines a frequency for the drive pulse of the stepping motor 4 based on a comparison result signal C in order to synchronize a recording speed to the transport speed of the film 5. Finally the mechanism 102 transmits a controlled motor drive signal (d) to the stepping motor 4 to control the speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a line-type color thermal transfer printer, and more particularly to a line-type color thermal transfer printer that controls the conveyance of an ink film.

[Conventional technology]

Conventionally, this type of line-type color thermal transfer printer prints using a strong ink film that is used to print bar codes.

FIG. 2 is a schematic perspective view of a line-type color thermal transfer printer showing an example of such a conventional printer.

As shown in FIG. 2, in a conventional thermal transfer printer, an ink film 5 sent out from an ink film supply roll 51 is tightly pressed together with a recording paper between a thermal head 1 and a platen 2, and is pressed in accordance with recorded image information (not shown). The ink ribbon 5 that has completed thermal transfer recording performs thermal transfer recording while being conveyed at a predetermined recording speed by a paper conveyance system.
is held between a film feed roller 31 and a pinch roller 32 in contact with the film feed roller 31 via a timing belt 8B by a stepping motor 4, and is conveyed while maintaining an appropriate tension in the conveyance direction via a timing belt 8A. A series of recording operations are performed in which the ink film is wound onto a take-up roll 52.

Further, when locating the ink surface of a predetermined color tone based on the color tone specification of the recorded image information, the thermal head 1 is detached from the platen 2 by a head retraction mechanism (not shown).
The stepping motor 4 is controlled at a predetermined speed by an open-loop control drive circuit (not shown), and drives the film feed roller 31 and the ink film take-up roll 52 via the timing belts 8A and 8B to convey the ink film 5. At this time, barcode sensor 6
By detecting the passing barcode 10, the color tone of the ink surface at each corner of the ink film 5 is recognized, and a "color search" operation is performed to locate the ink surface of a desired tone.

Here, FIG. 3 is a concrete detailed diagram of the barcode shown in FIG. 2.

As shown in FIG. 3, the barcode 10 formed on the ink film 5 is indicated by an arrow F in the transport direction of the ink film 5.
It is composed of a combination of a plurality of bars having different widths a 1 * a2 + a3 + a4. Here, it is shown as as < a2 < as < a4.

Therefore, the ink film 5 is transferred to the film feed roller 3.
1 and the pinch roller 32, and is transported at a constant speed without slipping.

Thereby, the barcode sensor 6 is configured to detect the difference in width of the barcode 10, ai r a 21 a s * a 4, and to recognize the information of the bar code 10 without fail.

On the other hand, when the rotational speed of the stepping motor 4 is constant, the circumferential speed of the ink film take-up roll 52 changes in accordance with the change in its diameter. In order to correct this, the conventional printer is configured such that the driving force of the stepping motor 4 is transmitted to the ink film take-up roll 52 via the friction clutch 7.

[Problem to be solved by the invention]

The conventional line-type color thermal transfer printer described above is equipped with a film feed roller and a pinch roller to convey the ink film at a constant speed. Moreover, since the driving force of the stepping motor is transmitted to the ink film take-up roll via a friction clutch, the cost increases due to the increase in parts, the size increases, and the friction coefficient of the rollers and clutch increases due to friction and deterioration over time. Also, the outer diameter of the roller changes, and the tension of the ink film becomes unstable due to the instability of the ink film transport speed, which causes deterioration of the recorded image quality and device reliability such as wrinkles of the ink film, sloping of the recording pitch, and misalignment of color overlap. It has the disadvantage of being inviting.

An object of the present invention is to provide a highly reliable line-type color thermal transfer printer that eliminates such occasional instability, improves image quality, reduces size, and improves economic efficiency.

[Means to solve the problem]

The line-type color thermal transfer printer of the present invention includes a comparison mechanism that calculates the ratio of the rotational speed of the motor that drives the ink film transport system and the period of the signal detected by the barcode detection means and compares it with a predetermined standard; The apparatus includes a motor control mechanism that controls the rotational speed of the motor based on the comparison result, and a motor whose rotational speed is controlled by the motor control mechanism and which drives an ink film conveyance system.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic perspective view of a line type color thermal transfer printer showing an embodiment of the present invention.

As shown in FIG. 1, in this embodiment, an ink film 5 is sent out from an ink film supply roll 51, is closely pressed together with a recording paper 9 by a thermal head 1 and a platen 2, and is maintained at a predetermined recording speed by a paper transport mechanism (not shown). The ink film 5 that has completed thermal transfer recording is wound onto an ink film take-up roll 52 via a timing belt 8 by a stepping motor 4 driven at a frequency synchronized with the aforementioned recording speed. At this time, the circumferential speed of the ink film winding roll 52 changes depending on its diameter, and the winding amount per unit rotation changes. Therefore, in order to synchronize the recording paper 9 and the ink film 5 that are transported at the aforementioned recording speed, the barcode detection signal a detected by the barcode sensor 6 is sent to the comparison mechanism 101. In the comparison mechanism 101, from the ratio of [the number of driving pulses of the stepping motor 4]:[the number of times of detection of the barcode detection signal a], that is, the intervals at which the barcodes 10 are formed in the transport direction of the ink film 5 are constant. Therefore, the winding amount of the single-reink film 5 for one drive pulse of the stepping motor 4 is calculated and compared with the reference value from the reference value storage section 103. A signal C, which is the result of the comparison, is sent to the motor control mechanism 102. The motor control mechanism 102 determines the frequency of the drive pulse of the stepping motor 4 for synchronizing the recording speed and the transport speed of the ink film 5 based on the comparison result signal C, and sends the controlled motor drive signal d to the stepping motor 4. and control its speed. That is,
Stepping motor 4. The bar code sensor 6, comparison mechanism 101 and motor control register 102 constitute a feedback control system.

On the other hand, during a "color search" operation in which the ink surface of a desired color is located based on the color tone specified in the recorded image information, the thermal head 1 is detached from the platen 2 by a head retraction mechanism (not shown), and the ink film 5 is moved by the paper transport mechanism described above. The recording paper 9 is separated from the recording paper 9 and is independently conveyed asynchronously with the recording paper 9. At this time, it is detected by the barcode sensor 6 similarly to the recording operation described above. The detection signal a of the barcode 10 on the ink film 5 is sent to a comparison mechanism 101. In the comparison fi structure 101, the winding amount of the ink film 5 per one driving pulse of the stepping motor 4 is calculated from the ratio of [number of driving pulses of the stepping motor 4]/[number of times of detection of the barcode detection signal]. , and the reference value from the reference value storage section ↓03. The comparison result signal C
is sent to the motor control mechanism 102. Motor control mechanism 1
In step 02, the driving frequency of the stepping motor 4 is determined based on the comparison result signal C to obtain a constant speed for reliably recognizing the information of the barcode 10 on the ink film 5, and the controlled motor driving signal d is applied to the stepping motor 4.
and control its speed. This also uses a feedback control signal.

〔Effect of the invention〕

As explained above, the color thermal transfer printer of the present invention includes a comparison mechanism that calculates the ratio between the rotational speed of the motor that drives the ink film transport system and the detection period of the barcode, and compares the ratio with a predetermined reference value; It has a motor control mechanism that controls the rotational speed of the motor based on the result, and this motor control mechanism controls the rotational speed of the motor that drives the ink film conveyance system, thereby reducing the friction coefficient due to friction of rollers etc. over time. It is possible to eliminate mechanical instability factors such as changes in the size and dimensions of the clutch, and changes in the friction coefficient of the friction plate of the clutch, and also to avoid wrinkles in the ink film, sloping of the recording pitch, and deviations in color overlap. It has the effect of realizing high-quality recorded images, being compact, low cost, and improving reliability.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of a line-type color thermal transfer printer showing an embodiment of the present invention, FIG. 2 is a schematic perspective view of a line-type color thermal transfer printer showing a conventional example, and FIG.
3 is a specific detailed view of the barcode shown in the figure; FIG. 1... Thermal head, 2... Platen, 4...
Stepping motor, 5... Ink film, 6...
・Barcode sensor, 8...Timing head, 9・
... Recording paper, 1 O... Barcode, 1... Comparison model, 2... Motor control mechanism, 103... Reference value storage unit.

Claims (1)

[Claims] A line-type color ink film on which heat-fusible inks of a plurality of different tones are applied in a field sequential manner and having a barcode representing each tone on the side edge thereof, and means for detecting the barcode are provided. In a line-type color thermal transfer printer that thermally transfers ink of a predetermined color tone onto a medium such as a recording paper according to recorded image information to obtain a desired multicolor recorded image, the rotation of a motor that drives the ink film conveyance system. a comparison mechanism that calculates the ratio of the speed and the period of the signal detected by the barcode detection means and compares it with a predetermined reference value; a motor control mechanism that controls the rotational speed of the motor based on the comparison result of the comparison mechanism; A line type color thermal transfer printer, comprising: a motor whose rotational speed is controlled by the motor control mechanism and which drives the ink film conveyance system.