JPH0657458B2 - Recording device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rule device, and more particularly to a recording device that performs a recording operation by a plurality of heating element groups arranged.

[Prior Art] Conventionally, a recording apparatus that performs a recording operation by heat generated from a heating element is known. One of such devices is a thermal transfer printer.

Most thermal transfer printers have a thermal head in which a plurality of heating elements are arranged, and by selectively driving the heating elements while moving the head, the ink on the thermal transfer ribbon is sequentially melted and transferred to a recording medium. By doing so, recording is performed.

The thermal transfer printer is small and lightweight, easy to maintain, low in operation noise, and good in storing the recorded results.
In recent years, it has been widely used as a recording output device such as a word processor.

However, the thermal transfer printer is a wire dot printer,
There is a drawback that the recording speed is slower than that of an inkjet printer. In the thermal transfer printer, it is necessary to prevent overheating of the thermal head for the reason described below in order to obtain good quality recording. In order to prevent overheating, it is normal to use a heat dissipation plate, and heat generation drive is not continuously performed, but a cooling time is usually provided between drives. It is this cooling time that makes it difficult to increase the recording speed of the thermal transfer printer.

Here, the structure of the conventional thermal head of FIG. 1 is shown. In the figure, reference numeral 1 is a heating element arranged on the surface of the glaze layer 3 on the substrate 2. One end is connected to the common electrode 4 and the other end is connected to the drive electrode 5, respectively.

FIG. 1 shows a one-column type head, but it is also known that the heating elements are arranged in a grid pattern of 5 × 7 rows or the like. However, in this type of grid type head, the heating element can be formed by forming a thin film of one layer in the one-row type, whereas a multi-layer thin film has to be formed, and the wiring of signal lines is complicated and the cost is likely to increase. Not used much because of its drawbacks 1
Column type is the mainstream.

By the way, this one-row type thermal head is moved in the horizontal direction of the figure and recording is performed by applying a heat pulse (recording current) to each heating element. However, in the case of a one-row type head, high-speed driving is performed. If it is attempted, the cooling time mentioned above tends to be insufficient.

In the case of high speed recording, since the heat pulse has to be continuously applied, the temperature of the element is not kept constant and tends to rise.

Overheating of the heat generating element is not preferable because it deteriorates the element and significantly deteriorates the recording quality. Therefore, in the one-row type thermal head, the drive interval is naturally restricted to prevent overheating, and it is difficult to improve the recording speed.

In view of the above points, a two-row type thermal head as shown in FIG. 2 has been considered. The head shown in FIG. 2 has heating elements in rows A and B arranged in line symmetry with respect to the center of the substrate 2. The heating element groups in rows A and B are formed of the same constituent members as described above, and these are shown by the same reference numerals with A and B added to the reference numerals in FIG.

The head shown in FIG. 2 has an A in the center of the heating element groups in rows A and B.
The common electrode 4 shared by the row and the row B is arranged, and there is an advantage that the structure can be constructed by the same plane configuration as that of the single row type.

As shown in FIG. 3, the head of FIG.
Is pressed against the recording medium 15 on the platen 14 via
When the element groups of the row and the row B are driven at the same time, double recording dots of the single row type can be formed at one head position. Therefore, it is possible to realize double the recording speed with respect to the single-row type head.

However, the conventional two-row type head has a drawback that the recording quality is poor as compared with the one-row type head. This is because when recording is performed while moving the head in the direction of the arrow in FIG. 3, the thermal transfer ribbons 16 that have been loaded in the row B behind the recording direction are already in the A direction.
It is heated near the row and has a certain amount of heat storage when it enters the row B position.

Therefore, the dots recorded in the B row on the rear side are always darker and larger than those in the A row, and the dot densities of the even dots and the odd dots are increased or decreased for each line, and the recording quality is improved. descend.

[Purpose] The present invention has been made in view of the above points, and an object of the present invention is to provide a recording apparatus which is excellent in recording quality and capable of high-speed recording.

In order to achieve the above object, the recording apparatus according to the present invention adopts the following configuration.

That is, the recording head includes a first heating element group including a plurality of heating elements and a second heating element group including a plurality of heating elements, and the recording head includes the first heating element for a recording material. Group and the second heating element group move relatively in a moving direction different from the arrangement direction, and an image is recorded on a recording material by heat generated from the first heating element group and the second heating element group. In the recording apparatus, the driving time of the heating elements of the second heating element group arranged on the downstream side of the first heating element group in the moving direction is defined as the driving time of the heating elements of the first heating element group. It is characterized by setting shorter than.

[Examples] Details of the present invention will be described below based on Examples shown in the drawings.

FIG. 4 is a perspective view showing an embodiment of the thermal transfer printer according to the present invention. A reference numeral 11 in FIG. 4 is a two-row type recording head having the same configuration as shown in FIGS. 2 and 3. The recording head 11 is slidably supported by a guide bar 20, and the pulse motor 22
Is reciprocated right and left along the cylindrical platen 14 via the wire 19 wound around the pulleys 16 and 21. Of the recording scans on the recording medium 15, the main scanning is performed by moving the carriage 18, and the sub-scanning is performed by moving the recording medium 15 in the direction of arrow P by the platen 14.

The recording head 11 is configured to swing by a driving unit (not shown) between a head-down position where the recording medium 15 is pressed against the recording medium 15 and a head-up position where the recording medium 15 is separated from the medium. The recording head 11 is pressed against the recording medium 15 via a thermal transfer ribbon, and the thermal transfer ribbon is housed in a ribbon cassette 17 and mounted on a carriage 18.

FIG. 5 is a block diagram showing the circuitry used to control the configuration of FIG. In FIG. 5, reference numeral 32 is a host-side device such as a facsimile device, a word processor, or a personal computer, and character or image data to be recorded is sent to the CPU 33 of the recording device through the signal line S1. The CPU 33 is composed of a one-chip element in which a RAM used as a buffer memory or the like and a ROM storing a program described later are integrally formed. The CPU 33 gives a drive signal to the driver 34 via the signal lines S2 and S3, and the driver 34 drives the recording head 11, the carriage feeding pulse motor 22, the paper feeding pulse motor 35, the thermal transfer ribbon shifting motor 36, and the like. The motor 37 for winding the thermal transfer ribbon is controlled. The driver 34 converts a drive signal of a logic level from the CPU 33 into a level necessary for driving each drive element, and a drive current of each element is a current 38 to a power switch 39.
Given through.

The recording head 11 has eight heating elements DA1 to DA, respectively.
8 and DB1 to DB8. In the example of FIG. 3, the reference numeral DA indicates the heating elements in the A-row, and the reference numeral DB indicates the heating elements in the B-row. The pulse motor 22 for the carriage and the pulse motor 35 for feeding the paper for driving the platen 14 are four-phase pulse motors and have four exciting phases S1 to S4 and F1 to F4, respectively. The ribbon motors 36 and 37 are composed of DC motors or stepping motors.

The host device transmits recording data and control codes such as carriage return and line feed via the signal line S1, and the CPU 33 controls the recording head 11 and each motor via the driver 34 based on the transmitted data to perform recording operation. .

FIG. 6A shows heating elements DA1 to DA of the recording head 11.
8 and DB1 to DB8 are shown. FIG. 6 (A) is a perspective view of the recording head 11 seen from the rear, and the positions of the heating elements are shown by broken lines. In particular, the heating element DB1 located on the rear side with respect to the recording direction indicated by the arrow
~ DB8 is indicated by a double circle.

In FIG. 6 (B), the characters “CANO” are recorded using the recording head 11.
The dot arrangement for recording "N" is shown. In FIG. 6 (B), circles indicate heating elements DA1 to DA8,
Double circles are dots recorded by the heating elements DB1 to DB8, respectively. That is, odd dots are heating elements DA1
.. DA8, even-numbered dots are recorded by the heating elements DB1 to DB8, respectively. However, as shown in FIG. 6 (A), since the two rows of heating elements are arranged at positions exactly separated by one dot, adjacent dots are recorded in a continuous recording cycle as described later. is not.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG. 7 and the timing chart of FIG.

FIG. 8 is a flowchart of the recording control of the CPU 33. When the recording data and the control data are transferred from the host device 32 through the signal line S1 in step S10 and the recording buffer is full and the preparation for recording is completed, the CPU 33 causes the stepping motor 22 to operate in step S11.
Of the excitation phases S1 to S4 of the carriage 18
Are set so that they move to the right in FIG. Succeedingly, in a step S12, it is determined whether the recording cycle is currently an odd cycle or an even cycle.

The recording cycle is indicated by the symbol C in FIG.
The lower four stages in FIG. 8 show the drive signals of the four excitation phases of the stepping motor 22.
2 is driven by two-phase excitation as shown in the figure, and the period from the switching of this excitation phase to the switching, that is, the carriage 1
The period in which 8 is stopped at one position corresponds to the length of the recording cycle C.

Reference numerals DA1 to DA8 and DB1 to DB8 in FIG. 8 respectively indicate the drive timings of the corresponding heating elements. The alternate long and short dash line in FIG. 8 indicates the delimiter of the recording operation for one character, and one character is performed exactly 7 times of the recording cycle, that is, 7 carriage positions.

If it is determined in step S12 in FIG. 7 that the cycle is an odd cycle, the process proceeds to step S18 to set the recording pattern of the odd cycle in the driver 34 via the signal line S2. In the example of FIG. 6, the first vertical 5 dot data of the first character "C" is set in the heating elements DA1 to DA8. As a result, in this recording cycle, the heating elements DA2 to DA2
A6 will be driven.

Subsequently, in step S19, a heat pulse is applied to the heating elements DA1 to DA8. The length of the heat pulse is step S
It continues until the timer 2 counts up at 20.
The time measured by the timer t1 corresponds to the time when the carriage 18 is stopped at one position, as shown in FIG. When the timer t1 counts up, the heat pulse of the heating elements DA1 to DA8 is cut off in step S21, and the process proceeds to step S22.

In step S22, the cycle counter for measuring the recording cycle is incremented by 1, and the process proceeds to step S23. In step S23, it is determined whether all the data in the print buffer has been recorded. If the recording is not completed, the process returns to step S11.

If it is determined in step S12 that the recording is for even cycles, the recording pattern for even cycles is set in the driver 34 through the signal line S2 in step S13.
Subsequently, in step S14, the operation is delayed by the time obtained by subtracting the measurement time of the timer t2 from the measurement time of the timer t1. Then, in step S15, the heating elements DB1 to DB
A heat pulse is applied to 8. This heat pulse is continued until the timer t2 counts up in step S16. When the timer t2 counts up, step S
At 17, the heat pulse of the heating elements DB1 to DB8 is cut off. Heat pulse length t2 of the heating elements DB1 to DB8
Since the thermal transfer ribbon has already been heated in the vicinity of the heating elements DA1 to DA8 and has a certain amount of heat storage, it can be obtained by subtracting the drive time corresponding to this amount of heat from t1. The delay correction in step S14 is to correct the shortening of the driving time so that the heating elements DB1 to DB8 are driven in one recording cycle.

By repeating the above operation, the character "CANON" in FIG. 6B is recorded. At this time, the characters indicated by double circles in odd rows are recorded by the heating elements DB1 to DB8, respectively, and the recording time t2 is shorter than that of the heating elements DA1 to DA8 as shown in FIG. As a result, the heat storage amount generated by the recording of the heating elements DA1 to DA8 located on the front side in the recording direction is corrected, and the densities of the heating elements DB1 to DB8 for recording even dots become equal to those of DA1 to DA8.

Comparing FIG. 6 (B) with FIG.
Since DA8 and DB1 to DB8 are exactly separated by one dot, it is understood that the adjacent odd dots and even dots are not actually recorded in the odd cycle and the even cycle.
As seen in FIG. 8, the first double circle dot in FIG. 6 is recorded just three cycles after the first circle dot (dotted line “C”) was recorded.

According to the above-described embodiment, it is possible to provide an excellent thermal transfer printer that can perform high-speed recording without using the two-row type recording head that can be manufactured at a cost substantially equal to that of the one-row type, without causing deterioration in recording quality due to uneven recording density.

Although the two-row type recording head has been illustrated above, the present invention is not limited to this.
It can be implemented even when using a recording head provided with heating elements in rows or more.

[Effect] As is apparent from the above description, according to the present invention, the second heating elements arranged downstream of the first heating element group in the moving direction are arranged.
Since the driving time of the heating elements of the heating element group is set shorter than the driving time of the heating elements of the first heating element group, the uneven recording density caused by heat accumulation is eliminated, and a recording device capable of high-speed recording is provided. It becomes possible to do.

[Brief description of drawings]

1 and 2 are front views showing different structures of conventional recording heads, FIG. 3 is a top view of the recording head of FIG. 2, and FIG. 4 is a structure of a thermal transfer printer according to the present invention. FIG. 5 is a perspective view, FIG. 5 is a block diagram showing the control system of the apparatus of FIG. 4, FIG. 6 (A) is a perspective view showing the structure of the recording head, and FIG. 6 (B) is recording by the recording head 11. FIG. 7 is an explanatory view showing the operation, FIG. 7 is a flow chart showing the control procedure of the CPU of FIG. 5, and FIG. 8 is a timing chart showing the operation when recording the characters of FIG. 6 (B). . 11 ... Recording head, 14 ... Platen 15 ... Recording medium, 18 ... Carriage 22 ... Pulse motor DA1-DA8, DB1-DB8 ... Heating element

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 8906-2C B41J 3/20 113 J

Claims (1)

[Claims] 1. A recording head having a first heating element group composed of a plurality of heating elements and a second heating element group composed of a plurality of heating elements, wherein the recording head is provided with respect to a recording material. Image is recorded on the recording material by the heat generated from the first heating element group and the second heating element group by moving relatively in a movement direction different from the arrangement direction of the heating element group and the second heating element group. In the recording device for recording, the driving time of the heating elements of the second heating element group arranged on the downstream side of the first heating element group in the moving direction is set to the heating element of the first heating element group. The recording device is characterized in that it is set shorter than the driving time of.