JPH11348334A - Printer - Google Patents

Abstract

(57) [Problem] To provide a printer in which the printing speed is changed in accordance with the gradation of an image to be printed and time is not wasted. SOLUTION: The print head 13 performs printing in line units.
Driving devices 18, 24, 2 for moving the printing paper at a predetermined printing speed in a direction orthogonal to the print line of the print head.
6, 28, 30, 32, and a control device 34 for controlling the print head and the drive device. The control device controls the drive device to change the printing speed according to the number of gradations of the image to be printed. It is characterized by:

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printer, and more particularly, to a printer having a print head for performing printing in line units.

[0002]

2. Description of the Related Art A printer having a print head for performing printing in line units is known. In this type of printer, printing is performed while the printing paper and the print head are relatively moved in a direction (sub-scanning direction) orthogonal to the line direction (scanning direction) of the print head.

In this type of printer, image information is
The data is converted into printer control information in line units, and printing is performed. In this type of printer, when one line of image information is converted into printer control information, one line of printing is performed based on the converted printer control information. Next, the image information of the next one line is converted into printer control information, and printing of the next one line is performed based on the converted printer control information. As described above, in this type of printer, conversion of one line of image information into printer control information and printing of one line are alternately performed. As a result, this type of printer requires at least time to convert at least one line of image information into printer control information between the printing of one line and the printing of the next line. Therefore, in this type of printer, the conversion speed of the image information affects the printing speed.

[0004]

The conversion of image information into printer control information requires a longer time as the gradation of the conversion source image information is higher (the number of gradations is larger). For example, if the time for converting the image information for one line of 64 tones into printer control information is t, the time for converting the image information for one line of 256 tones to printer control information is 4t.

As a result, when printing is performed based on high-gradation image information, printing of a certain line and printing of the next line can be performed as compared with the case of printing based on low-gradation image information. The time required between them increases. Therefore, when printing is performed based on high-gradation image information, the time interval for performing printing in line units must be set longer than when printing is performed based on low-gradation image information.

For these reasons, in a printer capable of performing printing based on high-gradation image information and low-gradation image information, the printing speed converts high-gradation image information to printer control information. When is set based on the required time. That is, in a printer capable of performing printing based on high-gradation image information and low-gradation image information, the time interval for performing printing in line units is at least
The time is set to a time required to convert high-gradation image information for one line into printer control information.

As a result, in this type of printer, when printing low-gradation image information, a waiting time is required between completion of image information conversion and printing in line units for each line printing. Will occur.

For example, image information of 256 gradations and 64
In a printer capable of performing printing based on gradation image information, the printing time interval in line units is set to at least 4t. Therefore, when printing is performed by this printer based on image information of 64 gradations, a wait time of at least 3t is generated for each printing of each line.

For this reason, in this type of printer, when printing is performed based on low-gradation image information, a waiting time is generated every time printing is performed in units of lines. However, there is a problem that it takes a longer time than necessary.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described problems, and has as its object to provide a printer in which the printing speed is changed in accordance with the gradation of an image to be printed and time is not wasted.

[0011]

According to the present invention, there is provided a printer comprising:
A print head that performs printing in line units, a driving device that moves the printing paper at a predetermined printing speed in a direction orthogonal to the print line of the print head, and a control device that controls the print head and the driving device. The control device controls the driving device to change the printing speed according to the number of gradations of the image to be printed.

According to such a configuration, the printing speed is set according to the number of gradations of the image to be printed. Therefore, the waiting time due to the change in the number of gradations of the image to be printed is reduced, and waste of time can be reduced.

In practicing the present invention, the control device may control the driving device to change the printing speed in accordance with the time for converting the image information of the image to be printed into the printer control information.

According to such a configuration, after converting the image information into the printer control information, the waiting time until printing in line units is reduced.

In practicing the present invention, when the driving device includes a stepping motor, the printing speed may be changed by changing the rotation speed of the stepping motor.

In practicing the present invention, the control device includes a gradation number determination unit for determining the number of gradations of the image to be printed, and the control device is configured based on the determination result of the gradation number determination unit. May be configured to change the rotation speed of the stepping motor.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the drawings merely schematically show the sizes, shapes, and arrangements of the components so that the present invention can be understood. Therefore, the present invention is not limited to the illustrated example.

FIG. 1 is a schematic diagram showing a configuration of a printer 10 according to an embodiment of the present invention. The printer 10 is capable of outputting image information of high gradation (256 gradations) or low gradation (64 gradations).
Is a color printer capable of printing a high-gradation (256 gradation) image or a low-gradation (64 gradation) image based on the above image information.

As shown in FIG.
Has a transport path 12. The printer 10 is configured to print on the printing paper while transporting the printing paper in the sub-scanning direction indicated by the arrow X in the transport path 12.

The thermal head 14 is sandwiched by the transport path 12.
And a platen 16 are arranged. Thermal head 1
4 has a plurality of heating elements. The plurality of heating elements are arranged side by side in a main scanning direction (the depth direction in FIG. 1) orthogonal to the transport direction X of the printing paper. The thermal head 14 is configured to perform printing in a line unit on printing paper by the heating elements. The thermal head 14 is configured to be able to move away from and approach the transport path 12 by a moving mechanism (not shown).

An ink ribbon (not shown) is arranged between the transport path 12 and the thermal head 14. When the thermal head 14 approaches the transport path 12, the printer 10 moves between the platen 16 and the thermal head 14.
The printing paper and the ink ribbon are sandwiched, and the ink of the ink ribbon is thermally transferred to the printing paper to perform printing in line units.

On the ink ribbon, monocolor ink layers of yellow (Y), magenta (M), and cyan (C) are formed side by side in the longitudinal direction. The printer 10 is configured to print a single color image corresponding to each ink layer on the printing paper while reciprocating the printing paper, thereby forming a color image on the printing paper.

A feed roller 18 and a pinch roller 20 are provided downstream of the thermal head 14 and the platen 16 in the sub-scanning direction. Feed roller 18
The pinch roller 20 and the pinch roller 20 are arranged to face each other with the transport path 12 interposed therebetween. The feed roller 18 has a shaft 18a, and a first pulley 22 is fixed to the shaft 18a.

Further, the printer 10 is provided with a stepping motor 24 capable of normal rotation and reverse rotation. The stepping motor 24 has an output shaft 24a. A pinion gear 26 is fixed to the output shaft 24a of the stepping motor 24. Therefore, the printer 10
Means that the rotation of the stepping motor 24 is
6 is transmitted.

Further, the printer 10 includes a reduction gear 28.
Are mounted so as to be rotatable about a shaft 28a.
The reduction gear 28 meshes with the pinion gear 26.
Therefore, the printer 10 is configured so that the rotation of the pinion gear 26 is transmitted to the reduction gear 28.
A second pulley 30 is fixed to a shaft 28a of the reduction gear 28.

The first pulley 22 and the second pulley 30 include:
An endless belt 32 is hung so as to transmit the rotation of the second pulley 30 to the first pulley 22.

As described above, the printer 10 controls the rotation of the stepping motor 24 by the rotation of the pinion gear 26 and the reduction gear 2.
8, second pulley 30, endless belt 32, first pulley 22
Through the feed roller 18.

The feed roller 18 and the pinch roller 20 are arranged so as to hold the printing paper on the transport path 12. Therefore, in the printer 10, the rotation of the stepping motor 24 drives the feed roller 18 to rotate, so that the printing paper is transported along the transport path. As described above, in the printer 10, a driving device is configured by the stepping motor 24, the pinion gear 26, the reduction gear 28, the second pulley 30, the endless belt 32, the first pulley 22, the feed roller 18, and the like. The drive device can move the printing paper relative to the thermal head 14 in a direction (sub-scanning direction) orthogonal to the print line of the thermal head 14 by rotating the stepping motor 24 forward or backward. And
By changing the rotation speed of the stepping motor 24, the speed of the relative movement between the printing paper and the thermal head 14 can be changed.

The printer 10 is provided with a control device 34. The control device 34 includes a microcomputer, and is configured to control operations of the thermal head 14, the stepping motor 24, and the like. Therefore, the printer 1
0 indicates that the stepping motor 24
The rotation direction, the number of rotations, and the like are controlled. Image information is input to the control device 34 from a personal computer or the like.

Further, the printer 10 is provided with a gradation input device 35. The gradation input device 35 is a device for the user to manually set whether to perform printing by the printer 10 at a high gradation or at a low gradation. Therefore, even if the image information is high-gradation image information, the user can select low-gradation printing by using the gradation input device 35.

Next, the configuration of the control device 34 will be described. FIG. 2 is a schematic block diagram illustrating a configuration of the control device 34. FIG. 2 shows only components related to the present invention for clarity.

The control device 34 includes a memory 340, a gradation determining unit 342, a converting unit 344, and a motor controlling unit 346.
And a head control unit 348.

The memory 340 is configured to store image information sent from a personal computer or the like.

Further, the gradation judging section 342 includes a memory 340
Is configured to determine the number of gradations of the image information stored in the. The gradation determination unit 342 includes the gradation input device 3
5 is connected. Then, when the user manually sets the print gradation via the gradation input device 35, the gradation determination unit 342 is configured to input the setting result.

As described above, the printer 10 is a printer capable of printing at a high gradation (256 gradations) and a low gradation (64 gradations). The gradation determining unit 342 determines whether the gradation of the image information stored in the memory 340 is 256 gradations or 64 gradations.
It is configured to determine whether or not the image is a gradation. However, when the user has manually set the print gradation via the gradation input device 35, the set gradation is used as the determination result. Further, the gradation determination unit 342 is configured to send the determination result to the motor control unit 346.

The conversion section 344 is configured to convert the image information whose gradation has been determined into printer control information. The time required to convert 256-level image information to printer control information is four times the time required to convert 64-level image information to printer control information.

The motor control section 346 includes a gradation determination section 342
Is transmitted to the stepping motor 24. Specifically, when the image information has 64 gradations, a motor control signal for rotating the stepping motor 24 at four times the speed of when the image information has 256 gradations is sent to the stepping motor 24. Have been. As a result, when it is determined that the image information has 256 tones, the printing paper is transported at the transport speed A, and when it is determined that the image information has 64 tones, the printing paper is transported at the transport speed 4A.
Conveyed by. The transport speed A is a speed at which the print paper is transported by one line while the image information of 256 gradations for one line is converted into printer control information and further sent to the thermal head 14. The transport speed 4A is a speed at which the printing paper is transported by one line while the image information of 64 gradations for one line is converted into printer control information and further sent to the thermal head 14. Therefore, in the printer 10, the speed of the relative movement between the thermal head 14 and the printing paper is changed according to the number of gradations of the image to be printed.

Further, the motor control unit 346 transports the printing paper to the printing start position at the time of starting printing, and discharges the printing paper from the printer 10 at the time of finishing printing.
The stepping motor 24 is configured to rotate forward. Further, when the printing of the monochrome image is completed, the motor control unit 346 reversely rotates the stepping motor 24 so as to return the printing paper to the printing start position.

The head controller 348 receives the printer control information converted by the converter 344 and generates a head control signal. The printer 10 is configured to cause a predetermined heating element of the thermal head 14 to generate heat in accordance with the head control signal to perform one-line printing. In the printer 10, the conversion unit 344 is configured to promptly issue a head control signal after completion of conversion of one line of image information, and to perform printing in line units.

As described above, in the printer 10, the printing paper is conveyed by one line while the image information for one line is converted into printer control information and sent to the thermal head 14. It is set to speed. Therefore, when the image information of the next line is converted into the printer control information and becomes ready for printing, the printing position of the next line of the printing paper is conveyed to the position of the thermal head 14. For this reason, it is possible to immediately print the line after the conversion of the image information is completed.

Next, the operation of the printer 10 will be described with reference to FIG. FIG. 3 is a flowchart illustrating the operation of the printer 10 in the printing process. The image information used here is image information in which the number of gradations does not change in one image. The image information is Y (yellow), M
(Magenta) and C (cyan) monochrome images are sent line by line. Then, the printer 10 prints the single-color images of Y, M, and C on the same printing paper in a superimposed manner to form a color image.

When printing is started, first, the controller 34
, The stepping motor 24 is operated to convey the printing paper to the printing start position by the driving device (S
1). Next, the gradation determination unit 342 determines whether the gradation of the image information for one line stored in the memory 340 is 64 gradations (low gradation) or 256 gradations (high gradation). A determination is made (S2). If it is determined that the gradation is 64 gradations, and if the user sets the printing gradation to 64 gradations via the gradation input device 35, the motor control unit 346 issues a motor control signal, Start rotating the stepping motor 24 so that the printing paper is transported at a speed of 4A (S
3).

Next, the 1 stored in the memory 340
The image information for the line is converted by the conversion unit 344 into printer control information of 64 gradations (S4). Then, the printer control information is sent to the head control unit 348. Then
The head control unit 348 performs, based on the printer control information,
A head control signal is issued to cause a predetermined heating element of the thermal head 14 to generate heat, and printing of one line is performed (S
5). The transport speed 4A of the printing paper is set to a speed of transporting the printing paper by one line while the image information of 64 gradations for one line is converted into printer control information and sent to the thermal head 14. Have been. Therefore, after the image information is converted into the printer control information, one line can be printed immediately. Therefore, no waiting time is generated every time printing is performed in units of lines.

Next, it is determined whether or not the printing of the currently printed monochrome image has been completed (S6). If NO, that is, if the printing of the single-color image currently being printed, for example, the yellow single-color image has not been completed, the process returns to S4. On the other hand, if YES, that is, if the printing of the currently printed single-color image has been completed, it is determined whether or not printing of all three-color single-color images has been completed (S7). If YES, that is, if it is determined that the printing of all the monochrome images is completed, the stepping motor 24 is operated under the control of the motor control unit 346 of the control device 34, and the printing paper is discharged from the printer 10 (S
9), printing ends.

On the other hand, if NO, that is, if it is determined that an unprinted single-color image remains, the stepping motor 24 operates under the control of the motor control unit 346 of the control device 34 to start printing the printing paper. Return to position (S
8) Return to S3. Then, the second or third single-color image is printed so as to overlap the first or second single-color image.

In S2, when it is determined that the image information has 256 gradations, and when the user sets the printing gradation to 256 gradations via the gradation input device 35, the motor control is performed. The unit 346 issues a motor control signal, and starts rotating the stepping motor 24 so as to convey the printing paper at the speed A (S10).

Next, the 1 stored in the memory 340
The image information for the line is converted by the conversion unit 344 into printer control information of 256 gradations (S11). Then, the printer control information is sent to the head control unit 348. Next, the head control unit 348 issues a head control signal based on the printer control information to cause a predetermined heating element of the thermal head 14 to generate heat, thereby printing one line (S).
12). The transport speed A of the printing paper is 256 for one line.
While the image information of the gradation is converted into the printer control information and sent to the thermal head 14, the printing paper is set to a speed for conveying the printing paper by one line.

Next, it is determined whether or not the printing of the currently printed single-color image has been completed (S13). If NO, that is, if the printing of the currently printed single-color image, for example, the yellow single-color image has not been completed, the process returns to S11. On the other hand, YE
If S, that is, if the printing of the currently printed single-color image is completed, it is determined whether or not printing of all three-color single-color images is completed (S14). If YES, that is, if it is determined that printing of all the monochrome images has been completed, the stepping motor 24 is operated under the control of the motor control unit 346 of the control device 34, and the printing paper is discharged from the printer 10 (S
16) Then printing is completed.

On the other hand, if NO, that is, if it is determined that the unprinted single-color image remains, the stepping motor 24 operates under the control of the motor control unit 346 of the control device 34 to start printing the printing paper. Return to position (S
15) Return to S10. Then, the second or third single-color image is printed so as to overlap the first or second single-color image.

As described above, the printer 10 is configured such that, when low-gradation printing is performed, the transport speed of the printing paper is increased. Therefore, even when low-gradation printing is performed, it is possible to print the line immediately after the conversion of the image information for one line is completed. Therefore, when printing a low-gradation image, there is no waiting time after the conversion of the image information.

The present invention is not limited to the above-described embodiment, and various changes can be made within the scope of the invention described in the claims, and these are also included in the scope of the invention. It goes without saying that it is included.

The printer 10 performs printing by using image information in which the number of gradations does not change in one image. However, the present invention is also applicable to a printer that can perform printing using image information in which the number of gradations changes in one image. The printer of such a modified example has basically the same configuration as the printer 10. However, the printer of this modification is different from the printer 10 in that the gradation determination unit 342 of the control device 34 is configured to perform the gradation determination on all the line-based image information. . The operation of such a printer will be described with reference to the flowchart of FIG. In the flowchart of FIG. 4, each step of the flowchart of FIG. The contents of each step in the flowchart of FIG. 4 are the same as the contents of the corresponding steps in the flowchart of FIG. 3, and a description thereof will be omitted.

There are two differences between the operation of the printer 10 and the operation of the modified printer. First, as shown in FIG. 4, in the printer of the modified example, it is determined whether or not the printing of the monochrome image currently being printed is completed (S106).
If NO in S113), the point is that the number of tones of the image information of the next line stored in the memory is determined (S102). Secondly, in the printer of the modified example, it is determined whether or not printing of all three monochrome images has been completed (S107 and S114).
Return the printing paper to the printing start position (S108 or S1
15) Then, the number of gradations of the image information of the next line stored in the memory is determined (S102). Therefore, in the printer of this modified example, the gradation of the image information of all the lines to be printed is determined. Then, the transport speed of the printing paper is changed based on the determination result.

Therefore, in such a printer, the printing speed corresponding to the number of gradations of the image information of each part is automatically set even while one image is being printed, and the waiting time is reduced. Can be reduced.

[0055]

As described above, according to the present invention, there is provided a printer in which the printing speed is changed in accordance with the gradation of an image to be printed, thereby eliminating waste of time.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a configuration of a printer according to an embodiment of the present invention.

FIG. 2 is a schematic block diagram illustrating a configuration of a printer control device according to the embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of the printer according to the embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of a printer according to a modified example of the printer of the embodiment of the present invention.

[Explanation of symbols]

 10: Printer 12: Conveyance path 14: Thermal head 16: Platen 18: Feed roller 18a: Shaft 20: Pinch roller 22: First pulley 24: Stepping motor 24a: Output shaft 26: Pinion gear 28: Reduction gear 30: Second Pulley 32: Endless belt 34: Control device 35: Gradation input device 340: Memory 342: Gradation determination unit 344: Conversion unit 346: Motor control unit 348: Head control unit

Claims (4)

[Claims] 1. A print head that performs printing in line units, a drive device that moves printing paper at a predetermined printing speed in a direction orthogonal to a print line of the print head, and controls the print head and the drive device. And a control device for controlling the drive device to change the printing speed in accordance with the number of gradations of the image to be printed. 2. The printer according to claim 1, wherein the control device controls the drive device to change the printing speed in accordance with a length of time for converting image information of an image to be printed into printer control information. A printer characterized in that: 3. The printer according to claim 1, wherein the driving device includes a stepping motor, and the printing speed is changed by changing a rotation speed of the stepping motor. Printer. 4. The printer according to claim 3, wherein the control device includes a gradation number determination unit that determines a gradation number of an image to be printed, and based on a determination result of the gradation number determination unit. Wherein the control device changes the rotation speed of the stepping motor.