JPH082032A - Paper forwarding device of printer and method of controlling the same - Google Patents

Abstract

PURPOSE:To provide the paper forwarding device of a printer and a method of controlling the same capable of shortening the time required for starting a new line in an operation for printing a plurality of pages, and also of maintaining a high accuracy of the paper forwarding operation. CONSTITUTION:This device includes a free rotating paper forwarding detector roller 9 adapted to be in contact with a part of paper 1 and designed to have its outer peripheral length L being the same as the length for starting a new line of the printing head and formed by a material with a small dimensional variation against temperature, a decode plate 11 formed with a slit 12 for coaxial rotation with the paper forwarding detector roller 9 and detecting a quantity of rotation of the paper forwarding detector roller 9, and a photosensor 13 for detecting the slit 12. In addition, it also includes a controller 14 for controlling a quantity of starting a new line of paper 1 on the basis of the detected signals of the photosensor 13, and a memory 16 connected to the controller 14 for storing a quantity of rotation of the stepping motor 2 required for each forwarding motion of starting for a new line.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device for a printer, and more particularly to a paper feeding device for a printer and a method for controlling the paper feeding device which is capable of high-precision and high-speed paper feeding control.

[0002]

2. Description of the Related Art In general, a paper feeding device of a printer transmits the rotation of a paper feeding motor to a paper feeding roller via a drive gear group, and the paper nipped by the paper feeding roller and a pressure contact roller is moved by a predetermined amount. It is formed so that it can only be transported.
When performing a line feed operation, the paper feed amount required for line feed is calculated, and the rotation amount of the paper feed motor is calculated based on the outer peripheral length of the paper feed roller and the mechanism of the drive gear group. The paper feed motor is rotated.

Then, the print head is driven on the basis of a desired print signal while moving the carriage 22, so that desired printing is performed on the paper.

However, in the above-mentioned conventional printer, the paper feed is caused by the eccentricity of each gear forming the drive gear group between the paper feed roller and the paper feed motor, the manufacturing error of the paper feed roller, the temperature change and the like. There is a variation in the amount, and particularly when performing graphic printing, the variation in the paper feed accuracy causes a decrease in print quality.

As a means for suppressing such variations in the paper feeding accuracy, the one described in Japanese Patent Laid-Open No. 4-193563 is known. In the one described in this publication, the reference roller is formed of a hard material having a small dimensional change with respect to temperature, and the reference roller is arranged so as to be in contact with a part of the paper conveyed by the paper feed roller. While making the rotation peripheral speed of the reference roller equal, a slit disk is coaxially provided on this reference roller, the rotation angle of the reference roller is detected by a photo sensor, and the detection result is fed back to the controller to feed the paper feed motor. By controlling the operation, the paper feed amount can be accurately determined.

[0006]

However, according to the above-mentioned conventional example, with respect to the variation of the outer peripheral length due to the manufacturing accuracy of the reference roller and the temperature change, the difference between the plurality of slits formed in the slit disk is reduced. The positional relationship should be accurately manufactured to improve the dimensional accuracy, and if there is a manufacturing error, the number of slits in the slit disk should be increased or decreased by using a photosensor to correct the paper feed amount. I had to do it. That is, the dimensional accuracy in the positional relationship between the slits of the slit disk greatly affects the paper feed amount.

Therefore, in the paper feeding apparatus as in the conventional example, the slit disk must be finished with excellent dimensional accuracy, which leads to an increase in cost and, moreover, the dimensional accuracy of the slit disk can be improved. It was quite difficult to secure the paper feeding accuracy in the unit of μm only by improving it.

Further, when a plurality of pages having the same content are printed, the detector detects the line feed width of each line for each page, resulting in a loss of time. In addition, when printing multiple colors, such as color printing, on the same surface at the specified printing position on the same line, the line width of each line was detected by the detector for each color. Occurs, and the detection accuracy of the detector deteriorates.

The present invention has been made in view of these points, and it is possible to suppress variations in the paper feed amount due to variations in the manufacturing accuracy of the reference roller and variations in dimensions due to temperature changes. Paper feed device of printer and its control that can shorten the time required for line feed when printing the same line feed content for the second time when printing the page It is intended to provide a method.

[0010]

In order to achieve the above-mentioned object, a paper feeding device of a printer according to the present invention according to claim 1 drives a paper feeding motor to rotate a paper feeding roller by a predetermined amount, and thereby the paper is fed. In a paper feeding device of a printer for feeding paper, the paper is brought into contact with a part of the paper conveyed by the paper feeding roller, the outer peripheral length is made substantially equal to the length of one line of the print head, and at least the temperature is changed. A rotatable paper feed detection roller whose part is made of a material whose dimensional change with respect to temperature is small, and a measurement point for rotating the paper feed detection roller coaxially and detecting the amount of rotation of the paper feed detection roller. And a detection device for detecting the detection part formed on the detection member, and the detection device includes the detection part. A control unit that controls the line feed amount of the paper based on the detected signal, and a storage unit that is connected to the control unit and sequentially stores the rotation amount of the paper feed motor required for each line feed of the paper It is characterized by being.

According to a second aspect of the present invention, there is provided a paper feeding device for a printer according to the first aspect, in which the control unit stores data of a rotation amount of one page of the paper feeding motor stored in the storage unit. Based on the above, the paper feed motor is driven to rotate forward or reverse so that the paper is fed from the first line or the last line.

According to a third aspect of the present invention, there is provided a paper feeding device for a printer according to the first or second aspect, wherein the paper feeding roller has a detected portion as a reference position for starting the paper feeding. In addition, a detection unit for detecting the detected portion and transmitting the detection signal to the control unit is provided.

According to a fourth aspect of the present invention, there is provided a method for controlling a paper feeding device for a printer, wherein the paper feeding device for a printer according to any one of the first to third aspects is used. In the control method of the paper feeding device of the printer, the paper feeding control by the control unit is based on the detection signal of the detected portion by the detection device at the time of the first printing by the ink portion of the first color in the case of performing color printing. Drive the paper feed motor to feed the line feed of the paper,
The rotation amount of the paper feed motor required for each line feed is sequentially stored in the storage unit, the printing of the first color is completed, and the next second
When printing a color, the paper feed motor is reversely rotated by the total paper feed amount stored in the storage unit to convey the paper to the first line feed position, and based on each line feed data stored in the storage unit. The paper feed motor is driven to feed a line feed.

According to a fifth aspect of the present invention, there is provided a method for controlling a paper feeding device for a printer, wherein the paper feeding device for a printer according to any one of the first to third aspects is used. In the control method of the paper feeding device of the printer, the paper feeding control by the control unit is based on the detection signal of the detected portion by the detection device at the time of the first printing by the ink portion of the first color in the case of performing color printing. Drive the paper feed motor to feed the line feed of the paper,
The rotation amount of the paper feed motor required for each line feed is sequentially stored in the storage unit, the printing of the first color is completed, and the next second
When printing the color, the line feed data required for line feed of the last line of the data stored in the storage unit is sequentially read out, and the paper feed motor is reversely rotated to print from the last line of the sheet, and line feed is performed. It is characterized by performing.

According to a sixth aspect of the present invention, there is provided a method of controlling a paper feeding device of a printer according to the present invention, which is a method of controlling a paper feeding device of a printer which performs paper feeding using the paper feeding device of the printer according to the third aspect. In the paper feed control by the control unit, when the number of pages to be printed is plural, the first page is printed by the detection unit detecting the detected portion which is the reference position of the paper feed formed on the paper feed roller. At this time, the paper feed motor is driven based on the detection signal of the detected portion by the detection device to start line feed, and the rotation amount of the paper feed motor required for each line feed is sequentially stored in the storage unit. In addition, when printing the second and subsequent pages, the printing is always started from the detected portion and the line feed of the paper is performed based on the data stored in the storage portion.

[0016]

In the present invention, the paper is inserted into the portion where it is joined to the paper feed roller, and the paper feed motor is driven to rotate the paper feed roller to convey the paper by a predetermined amount and perform line feed.

At this time, the rotation peripheral speed and the rotation amount of the paper feed detection roller are equal to the feed speed and the feed amount of the paper. Therefore, the detected member that rotates coaxially with the paper feed detection roller also rotates at the same rotation angular velocity and rotation amount. Then, when the paper feed detection roller makes one rotation, the paper is fed by one line feed. Further, the detector detects a detected portion formed as a measurement point on the detected member, the control unit detects the feed amount of the paper based on this signal, and sends a command to the paper feed motor to send the paper. The line feed is controlled, and the rotation amount of the paper feed motor required for this line feed is sequentially stored in the storage unit. Then, on a page that can be printed with a line feed width equivalent to this line feed data, the line feed control of the paper is performed based on the stored data stored in the storage unit without detecting the detected portion again by the detector. .

[0018]

The present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of a paper feeding device of a printer according to the present invention. First, in order to perform printing by a print head such as a thermal head (not shown), the paper 1 is conveyed with a small number of steps. A stepping motor 2 serving as a drive source is provided, and as a power transmission mechanism group of the stepping motor 2, a drive gear 4 directly connected to a rotary shaft 3 of the stepping motor 2 and the drive gear 4
A transmission gear 5 that meshes with and transmits power, and a rotary gear 8 that meshes with the transmission gear 5 and is directly connected to the rotary shaft 7 of the paper feed roller 6 are provided. Further, the paper feed roller 6 has a rotary shaft 7 arranged in parallel with the rotary shaft 3 of the stepping motor 2 so that the paper 1 inserted from an insertion opening (not shown) of the paper 1 is fed to a platen (not shown). It's supposed to be sent to the front of ().

Further, a paper feed detection roller 9 is arranged in parallel with the rotary shaft 7 of the paper feed roller 6, and the paper feed detection roller 9 has a peripheral speed equal to the speed at which the paper 1 is fed. In order to rotate the sheet 1, the sheet 1 freely rotates in the conveying direction and is in contact with a part of the sheet 1 so as to sandwich the sheet 1 together with the sheet feed roller 6, and the outer peripheral length L thereof The length is set to be equal to or slightly shorter than the length L _O of one line feed (for example, the range of one row of the heating element of the thermal head) at the time of line feed. That is, it is desirable that the dimensional error be within the range of L ≦ L _O. Therefore, the paper feed detection roller 9 rotates once for each line feed of the paper 1.

Further, the paper feed detection roller 9 is made of a ceramic material or a metal material which has a small dimensional change with respect to temperature and is excellent in wear resistance at least in a portion which is easily affected by heat, and the temperature change is caused. It is possible to prevent the dimensional variation due to. The outer peripheral surface of the paper feed detection roller 9 in contact with the paper 1 is about 3 μm so that the friction coefficient for the paper 1 is increased.
The surface roughness is about 200 μm to prevent the paper feed detection roller 9 from slipping on the contact surface with the paper 1 and erroneously detecting the line feed width.

A decode plate 11, which is a member to be detected, is connected to the rotary shaft 10 of the paper feed detection roller 9 so as to rotate coaxially with the paper feed detection roller 9. A plurality of slits 12 are formed on the outer circumference of the decoding plate 11 as a detected portion, and a photosensor 13 which is a detector for detecting the plurality of slits 12 and transmitting the signal to the control portion 14 is provided. Has been.

Further, the control unit 14 is connected to a drive control unit 15 such as a driver which is controlled based on a command from the control unit 14 in order to drive the stepping motor 2, and each line feed. A storage unit 16 is connected to store the number of drive steps transmitted as a command to the drive control unit 15 for feeding, for one page from the first line feed to the final line feed.

The control unit 14 corrects the error in the feed amount caused by the variation in the size of the paper feed detection roller 9 due to the manufacturing precision and the temperature change, and the plurality of slits 12 as shown in FIG. One of the reference measurement points 12A as the reference position is selected from the
When A is rotated once and detected by the photo sensor 13 again, the number of rotations up to the detected position is added with the number of correction pulses based on the reference number of correction pulses specific to the apparatus, which is previously determined by a test / inspection. Then, a command is transmitted to the drive control section 15 to feed the sheet 1, and the stepping motor 2 is controlled.

If this correction is repeated, the accuracy is deteriorated at a certain point due to the accumulation of the correction. Therefore, in order to prevent the accuracy of the correction from deteriorating, the setting of the reference measurement point 12A selected from the plurality of slits 12 is canceled before the allowable range is exceeded,
The slit 12 closest to the photosensor 13 at the time of line feed is selected again as a new reference measurement point 12B.

On the other hand, the control section 14 controls the above-mentioned paper 1
In addition to controlling each line feed, the number of driving steps of the stepping motor 2 required for this line feed is stored in the storage unit 16. That is, each line feed in one page is based on one rotation of the paper feed detection roller 9, but since the paper feed roller 6 is not a perfect circle, the line feed detection roller 9 requires one rotation. The number of driving steps of the stepping motor 2 is different for each line feed. Therefore, the reference slit 12 is set for each line feed.
A must be detected. Therefore, if the number of drive steps for each line feed is stored in the storage unit 16 from the first line to the last line and the line feed data for one page is stored, the line feed width is equivalent to this page and When printing pages that can cause line breaks with the same number of driving steps, for example, when printing multiple pages with the same content, or when printing multiple pages with different content but the same number of lines, or color printing. When printing is performed, the paper can be fed based on the stored data of the number of driving steps without detecting the reference measurement point 12A by the photosensor 13 again.

Next, the control method of the above-described embodiment will be described.

In the present embodiment, the sheet 1 is inserted into a portion to be joined with the sheet feed roller 6 and the stepping motor 2 is driven to drive the drive gear 4, the transmission gear 5, the rotary gear 8 and the like. The paper feed roller 6 is rotated through the transmission mechanism to convey the paper 1 by a predetermined amount and perform line feed.

At this time, since the roller portion of the paper feed detection roller 9 is in contact with a part of the paper 1 and the outer peripheral surface thereof is finished to have a surface roughness of about 3 μm to 200 μm, The peripheral speed and amount of rotation of the paper feed detection roller 9 do not slip with respect to the paper 1 and are accurately dependent on the rotation of the paper feed roller 6,
It becomes equal to the paper feed speed and feed amount of the paper 1. Further, since the decoding plate 11 is also provided coaxially with the rotation shaft 10 of the paper feed detection roller 9, it similarly rotates at the same angular velocity and amount of rotation as the paper feed detection roller 9. Then, the photo sensor 13 detects passage of the plurality of slits 12 formed on the outer periphery of the decoding plate 11, and the signal is fed back to the control unit 14, so that the drive control unit is controlled by the control unit 14. A command for driving the stepping motor 2 by the required number of driving steps is transmitted to the drive controller 15. Based on the command, the drive control unit 15 controls the stepping motor 2, and as a result, the paper feed of the paper 1 is controlled. Will be done.

On the other hand, as described above, the outer peripheral length L of the paper feed detection roller 9 is equal to or slightly shorter than the length L _O of one line feed of the paper 1, If the paper feed of the paper 1 is stopped at the position where the paper feed detection roller 9 makes one rotation, that is, one of the plurality of slits 12 formed on the decoding plate 11 is detected by the photo sensor 13, This is the control unit 1
4 is set as the reference measurement point 12A, and when the reference measurement point 12A is detected again, the paper feed of the paper 1 is stopped. It has been completed, and μ
It is possible to feed a line feed in m units.

In order to detect the reference measurement point 12A, the number of times the photosensor 13 detects the plurality of slits 12 when the decoding plate 11 makes one rotation is measured in advance, and this is measured by the control unit. It should be stored in 14.

As described above, the line feed of the sheet 1 is controlled, and the number of driving steps of the stepping motor 2 required for the line feed is sequentially stored in the storage unit 16 from the first line feed of the page. The number of drive steps for one page until the last line feed is stored as line feed data. Then, when printing a page that allows line breaks with the same number of drive steps as each page, for example, pages with the same content or pages with different content but with the same number of lines and continuous on multiple sheets In the case of printing at the same time, or after printing a page with a different line feed width in the middle and printing again uniformly with the same line feed width as the original, the photo sensor 13 is used again as the reference measurement point. 12A
The paper 1 is fed while each line feed is performed based on the storage data of the number of drive steps stored in the storage unit 16 without detecting the error.

The control method as described above can be applied to, for example, color printing. That is, FIG.
Each color is repeated in the longitudinal direction in the order of Y (yellow), M (magenta), C (cyan), and B (black), as shown in, and is formed to have an area larger than the printing area of the paper 1. Then, set the color film type ink film in the position of the ink film cassette (not shown). First, in order to print one page using the Y ink portion as the first color, line feed is sequentially performed by the control method described above, and the stepping motor 2 required for line feed is driven. The number of steps is stored in the storage unit 16. When the printing with Y is completed, the storage unit 16 sequentially stores one page of line feed data from the number of drive steps required for the first line feed to the number of drive steps required for the last line feed. There is.
Next, when printing is performed using the M ink portion of the second color after completion of printing in Y, first, the stepping motor 2 is driven by the total number of driving steps required for printing in Y described above. Is rotated in the reverse direction to return the sheet 1 to the initial position, and then the control unit 14 reads the line feed data for one page stored in the storage unit 16 and sequentially instructs the drive control unit 15. The stepping motor 2 is driven to rotate, and printing with M is performed. Further, when the printing with M is completed, the printing with the ink portion of C or the ink portion of B is the same as the printing of the ink portion of M with the number of driving steps stored in the storage unit 16 at the time of printing with Y. The control of line feed based on this will be repeated.

Then, when printing in all colors is completed, the paper 1 is discharged.

As described above, according to the present embodiment, the paper feed detection roller 9 makes one revolution for each line feed (range of one row of the heating elements of the thermal head), so that the paper feed detection roller 9 and the gears are rotated. It is possible to ignore variations in the paper feed amount due to eccentricity such as the above or loss of each drive transmission system, and it becomes possible to perform line feed with high accuracy.

Further, according to the conventional example, the photo sensor 1
3 detects the different slits 12 at each line feed, and the feeding accuracy of the sheet 1 was greatly affected by the respective accuracy among the plurality of slits 12. On the other hand, in the embodiment of the present invention, since the outer peripheral length L of the paper feed detection roller 9 is the length L ₀ of about one line feed of the paper 1, the photo sensor 13 is
The same slit 12 is detected at the start and end of the paper feed of the paper 1. Then, when correction is necessary, instead of detecting the other slits 12,
The stepping motor 2 can be corrected in small steps based on a predetermined reference correction pulse number.

Therefore, it is not necessary to increase the accuracy of the slits 12 formed on the decoding plate 11, which leads to cost reduction, and it is possible to secure the accuracy of sheet feeding in μm unit even with the inexpensive decoding plate 11.

In addition, when printing pages of the same content on a plurality of pages, when printing pages having the same number of lines but different contents on a plurality of pages, or when performing color printing, one page is printed. When printing on a page in which the number of stepping motor 2 driving steps required for each line feed is the same,
By storing the number of driving steps required for each line feed for one page at the time of the first printing, the photo sensor 13 does not need to detect again for each line feed, so that the line feed speed is increased and the printing speed is significantly improved. Up to.

Further, in the conventional example, when printing the second and subsequent colors, the inks of a plurality of colors are overlapped with each other to form unevenness, and the paper feed detection roller which rotates in contact with the uneven portion of the paper 1. Since the rotation of 9 causes variations in the paper feeding accuracy due to multiple closed loops, according to the present embodiment, the line feed data of the first color that most accurately rotates and determines the line feed width. Since the second color and subsequent colors will be printed on the basis of
High accuracy similar to that of the color can be obtained.

Next, another embodiment of the paper feed control method of the printer of the present invention will be described.

First, of the control methods of this embodiment, the paper feed control method for printing the Y (yellow) ink portion that is the first color printing and the line feed data for one page at this time are stored in the storage unit 16. The control method to be stored in is the same as that of the above-mentioned embodiment. When the printing with Y is completed, the paper 1 is not conveyed backward in this embodiment, and the printing of the ink portion of M (magenta) is started from the last line in reverse. That is, the control unit sequentially reads the number of drive steps stored in the storage unit 16 from the last line every time it prints one line, and prints it while rotating the stepping motor 2 in the reverse direction via the drive control unit 15. . Then, when printing is performed up to the first line and printing with M is completed, printing from the first line to the ink portion of C (cyan) is performed based on the number of drive steps stored in the storage unit 16. It will start.

According to the control method of this embodiment as described above,
Since it is not necessary to reversely rotate the stepping motor 2 by the total number of driving steps stored in the storage unit 16 to return the paper 1 to the initial printing position, it is possible to print at a higher speed. Therefore, similar to the control method described above, it is possible to secure the accuracy of sheet feeding in the unit of μm at low cost, and it is possible to print at a higher speed.

Further, although the above-mentioned embodiment relating to the paper feed control method of the printer is related to the color printing control method by the color damper system, as another embodiment, in the case of color printing by the cassette changer system. Will be described.

FIG. 4 shows a thermal transfer printer 19 which employs a cassette changer system. The structure of the thermal transfer printer 19 will be briefly described. First, a flat platen 20 is placed at a desired position on a frame (not shown). The printing surface is arranged to be substantially vertical, and a guide shaft 21 is arranged below the front side of the platen 20 in parallel with the platen 20. A vertically divided carriage 22 is attached to an appropriate position of the guide shaft 21, one of which is shown below is a lower carriage 22a which is attached to the guide shaft 21 and is shown above. The other is an upper carriage 22b to which a ribbon cassette 23 for accommodating an ink ribbon is attached and which is vertically movable to and from the lower carriage 22a. The carriage 22 is driven by an appropriate driving means (not shown) such as a stepping motor,
It is adapted to be reciprocally driven along the guide shaft 21. A thermal head 24 that prints on a recording medium (paper, not shown) is disposed on the carriage 22 at a position facing the platen 20.

Further, in the central portion of the upper carriage 22b,
A pair of rotatable bobbins 25 are arranged at a predetermined interval from each other.
6 is capable of traveling in a predetermined direction. Carriage 2
A reflection type optical sensor 27 is provided as a sensor for detecting the type of the ink ribbon 26 housed in the ribbon cassette 23 on the edge farther from the second platen 20.

The optical sensor 27 is a thermal transfer printer 19
Is connected to a controller 28 that controls the printing operation of the thermal transfer printer 19 disposed at the desired position.
The controller 28 is formed by a memory, a CPU, and the like (not shown), and based on at least the output signal from the optical sensor 27 accompanying the movement of the carriage 22, the presence / absence of the ribbon cassette 23 and the ink stored in the ribbon cassette 23. The type of ribbon 26, the movement distance of the carriage 22 with respect to the home position, the open / closed state of a canopy 29, which will be described later, and a pair of adjacent or separated ribbon cassettes 23.
It is possible to determine or detect the distance between them.

Above the carriage 22, a substantially plate-shaped canopy 29, which is supported by a frame (not shown) so as to be openable and closable as shown by a double-headed arrow A in FIG. 5, is arranged. The canopy 29 functions as a paper retainer on the exit side of a paper feed mechanism (not shown) in the closed state, and faces the carriage 22 to have a length substantially the same as the moving area of the carriage 22. Has been done.

A ribbon cassette 23 is provided at a predetermined position on the lower surface of the canopy 29, which faces the carriage 22 in parallel.
There are provided a plurality of cassette holders (not shown) for holding the four ink ribbons 2 for performing multicolor printing in this embodiment.
Ribbon cassettes 23a, 23b, 23c and 23d accommodating 6a, 26b, 26c and 26d are carriages 22.
Are arranged in a line in the moving direction. Then, each ribbon cassette 23a, 23b, 23c, 23
d is a canopy 29 as indicated by a double-headed arrow B in FIG.
And the upper carriage 22b are selectively transferred.

Each ribbon cassette 23a, 23 of this embodiment
Regardless of the type of the ink ribbon 26, all of b, 23c, and 23d are formed in the same shape and the same size, and are rotatably supported by a pair of upper and lower case main bodies 30 that are substantially rectangular in plan view. The ink ribbon 26 is wound between the pair of reels, and the middle portion of the ribbon path of the ink ribbon 26 is led out to the outside. When the pair of reels is mounted on the upper carriage 22b, one of the reels is a take-up reel that winds the ink ribbon 26 of the portion used for printing, and the other is a delivery reel that delivers the ink ribbon 26. It is said that Further, a concave portion 33 facing the thermal head 24 is formed on a surface of the ribbon cassette 23 which is mounted on the carriage 22 and faces the platen 20, and an intermediate portion of the ink ribbon 26 is led out in the concave portion 33. ing.

On the rear surface of the ribbon cassette 23, which extends parallel to the surface on which the recess 33 is formed, the ink ribbon 2
Identification marks 31 for identifying the six types are arranged. The identification mark 31 of this embodiment is the ink ribbon 26.
It is formed by the reflective seal 34 having the striped non-reflective portions 32 that differ in number depending on the type.

Then, the identification mark 31 is detected by the optical sensor 27, and the detection signal is output to the control unit 25 of the printer, and the number of the identification mark 31 in each ribbon cassette 23 is counted in the control unit 25. As a result, the type of the ink ribbon 26 contained in the ribbon cassette 23 is determined.

The carriage 22 can be stopped when the optical sensor 27 detects the identification mark 31 to be used, and the ribbon cassette 23 is transferred to the upper carriage 22b in a state where the carriage 22 is stopped. It is like this.

Inside the cassette changer type thermal transfer printer, a paper feed detection roller 9, a control unit 14, a storage unit 16 and the like as shown in FIG. 1 are arranged. In the color printing control method with such a configuration, first, when printing the first color, the optical sensor 27 detects the identification mark 31, and the controller 28 is required from among the signals. When the identification mark 31 corresponding to the ink ribbon 26 is discriminated, the movement of the carriage 22 is stopped and the ribbon cassette 23 is transferred from the canopy 29 to the upper carriage 22b. Then, the ink ribbon 26 contained in the ribbon cassette 23 is fed and wound by the rotation of the bobbin 25, and the heat of the thermal head 24 causes heat transfer to the recording medium one after another to print one page. To finish. In the printing of the first color, each line feed is lined according to the rotation width corresponding to the rotation amount of the paper feed detection roller 9 for one rotation, and at the same time, the number of steps of the stepping motor required for each line feed is the storage unit at any time. 16
Is stored. Next, in the case of printing the second color, first, the first color ribbon cassette 23 is returned to the canopy 29, and the second color ink ribbon 26 is selected from the signals detected by the optical sensor 27. The identification mark 31 is identified by the controller 28, and the ribbon cassette 23 of the second color is transferred from the canopy 29 to the upper carriage 22b. During this time, the stepping motor is reversely rotated by the total number of steps for one page stored in the storage unit 16 and the paper is returned to the initial position. Therefore, when printing the second color, ,
Printing is performed while line feed is performed based on each line feed data of the storage unit 16, and the slit 12 of the decoding plate 11 is not detected again by the photo sensor 13. Then, the printing for the second and subsequent colors is also performed by the same method as for the second color.

According to such an embodiment, it is not necessary to increase the accuracy of the slits 12 formed on the decoding plate 11, which leads to cost reduction, and even with the inexpensive decoding plate 11, the accuracy of sheet feeding in μm unit is secured. Further, the number of driving steps required for each line feed for one page at the time of the first printing is stored in the storage unit 16, so that it is not necessary to detect the photo sensor 13 again for each line feed. The line feed speed is faster and the printing speed is much faster.

Further, it is possible to prevent the deterioration of the paper feeding accuracy caused by the influence of the uneven surface formed on the paper due to the overlapping of the inks of a plurality of colors, and the printing accuracy of the second and subsequent colors is as high as that of the first color. Will be obtained.

On the other hand, in the printing of the second and subsequent colors, the paper is conveyed backward to the first position and the printing in the next color is started after the printing of one page is completed. It is also possible to call the line feed data in order from the position of the last line where the printing has been completed, and feed the line feed while rotating the stepping motor in the reverse direction.

According to the control method of this embodiment as described above,
Since it is not necessary to reversely rotate the stepping motor 2 by the total number of driving steps stored in the storage unit 16 to return the paper 1 to the initial printing position, it is possible to print at a higher speed. Therefore, similarly to the control method described above, it is possible to secure the accuracy of sheet feeding in the unit of μm at low cost, and it is possible to print at a higher speed.

Next, another embodiment relating to the paper feeding device of the printer of the present invention is shown in FIG.

First, the stepping motor 2 as a drive source is provided, and the drive gear 4 and the transmission gear 5 as a power transmission mechanism group of the stepping motor 2 are arranged.
And the rotary gear 8 is provided. The paper feed roller 6 is provided with a slit 12 which serves as a reference for detecting the initial position during printing, or a detected portion 17 such as a reflecting plate. A detection unit 18 such as a photo sensor for detecting and transmitting the signal to the control unit 14 is provided.

Further, the paper feed detection roller 9 is arranged so as to be parallel to the rotary shaft 7 of the paper feed roller 6 and to be in contact with a part of the paper feed roller 6 for nipping the paper 1. A decoding plate 11, which is a member to be detected, is connected to a rotary shaft 10 of the paper feed detection roller 9 so as to rotate coaxially with the paper feed detection roller 9. A plurality of slits 12 are formed on the outer periphery of the decoding plate 11 as a detected portion, and a photo sensor 13 which is a detector for detecting the plurality of slits 12 and transmitting a signal thereof to the control unit 14 is provided. It is provided.

Further, the control unit 14 stores a drive control unit 15 for controlling the stepping motor 2 based on a command from the control unit 14 and a driving step number required for each line feed. The storage unit 16 is connected.

The paper feeding device of this embodiment is applied especially when the pages to be printed extend over a plurality of pages.

Next, the control method of this embodiment will be described.

In the control method of this embodiment, each line feed and the number of drive steps required for this line feed are stored in the storage unit 16.
The control method relating to storing in the above is the same as the control method of the above-described embodiment, and thus the details thereof will be omitted.

First, when the number of pages required for printing is a plurality of pages, the printing position on the paper feed roller 6 is different for each page, and as described above, the paper feed roller 6 is not a perfect circle. Therefore, even if the line feed positions are the same, the number of driving steps of the stepping motor 2 required for line feed differs if the page is different. Therefore, even in such a case, in order to effectively utilize the line feed data of the number of drive steps stored in the storage unit 16, the paper feed roller 6 is provided with the detected unit 17 serving as a reference indicating the initial position. By detecting the detected portion 17 by the detecting portion 18 and controlling it by the control portion based on the signal, each sheet 1 is always
The printing start position of is to be performed from this reference position.

According to such an embodiment, when the first page is printed, the number of drive steps required for each line feed is detected and stored in the storage unit 16, so that the second and subsequent pages are printed. With respect to printing, line feed can be performed based on the stored data, so that high-speed and high-precision paper feeding can be performed regardless of the eccentricity of the paper feeding roller 6 or the like.

The present invention is not limited to the above-mentioned embodiment, but various modifications can be made if necessary. For example, the printing described in the present embodiment is not limited to only the color printer or the monochrome printer, but is applicable to both. Further, the color printing method can be applied to both the so-called color-dunderer method and the cassette change method.

Further, in the present embodiment, the platen 20 and the paper feed roller 6 are provided separately, but the platen 20 and the paper feed roller 6 may be integrally configured to have the functions of both. The position where the paper feed detection roller 9 is provided does not have to be limited to the position where the paper 1 is sandwiched together with the paper feed roller 6, and may be any position that can measure the rotation amount of the paper 1 depending on its rotation.

Further, in this embodiment, the mechanism in which the stepping motor 2 and the paper feed roller 6 are connected by the gear group has been described, but the transmission ratio is appropriately adjusted by using other transmission means such as a timing belt. You may apply to the mechanism which was made.

[0070]

As described above, since the paper feeding device of the printer according to the present invention feeds one line of paper per one rotation of the paper feeding detection roller, it is concerned with the eccentricity of the paper feeding detection roller and the accuracy of the detected member. Therefore, it is possible to secure the sheet feeding accuracy in the unit of μm.

Further, when printing a plurality of pages with the same line feed content, the rotation amount of the drive motor required for each line feed of the first page is stored for one page, and the second and subsequent printings are performed based on this stored data. Since the detector does not have to detect the line feed width for each line feed again, the printing speed can be significantly increased.Also, with the detected portion formed on the paper feed roller as the reference, Since printing can be started from a position, highly accurate printing can be performed regardless of eccentricity of the paper feed roller.

In the case of color printing or the like, after the first color is printed, the second and subsequent colors are printed from the first line or the last line based on the line feed data stored in the storage section. Since the line width is printed and the line width is not detected again by the detector, the time required for detection is not wasted.Furthermore, the uneven surface generated when the inks of the respective colors overlap causes the detection accuracy of the detection roller to increase. Highly accurate color printing is possible because it is not affected by deterioration.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of a paper feeding device of a printer according to the invention.

FIG. 2 is an enlarged explanatory diagram of a decoding plate in the present embodiment.

FIG. 3 is an explanatory diagram of a color ink film used in a color damper system in this embodiment.

FIG. 4 is a perspective view of a thermal transfer printer using a cassette change system according to this embodiment.

5 is a schematic side view of a main part of FIG.

FIG. 6 is a perspective view of a main part showing another embodiment of the paper feeding device of the printer according to the invention.

[Explanation of symbols]

 1 Paper 2 Stepping Motor 4 Drive Gear 6 Paper Feed Roller 9 Paper Feed Detection Roller 11 Decode Plate 12 Slits 12A, 12B Reference Measurement Point 13 Photo Sensor 14 Control Section 15 Drive Control Section 16 Storage Section 17 Detected Section 18 Detection Section 22 Carriage 23 ribbon cassette 26 ink ribbon 27 optical sensor 31 identification mark

Claims (6)

[Claims] 1. A paper feeding device of a printer, which drives a paper feeding motor to rotate a paper feeding roller by a predetermined amount to feed a paper, wherein the paper feeding roller is in contact with a part of the paper, A rotatable paper feed detection roller having a length substantially equal to the length of one line feed of the print head, and at least a portion subjected to temperature change is formed of a material whose dimensional change with temperature is small, and this paper feed detection roller. A detected member that is rotated coaxially with the roller and has a detected portion that serves as a measurement point for detecting the amount of rotation of the paper feed detection roller, and the detected portion formed on the detected member. A detection device for detecting, a control unit for controlling the line feed amount of the paper on the basis of a signal for the detection device to detect the detected portion, and a control unit connected to this control unit Paper feeder of the printer, characterized in that it has a storage unit for amount of rotation sequentially storing of the paper feed motor required for each new line feed. 2. The control unit controls the paper feed so that the paper is fed from the first line or the last line based on the data of the rotation amount for one page of the paper feed motor stored in the storage unit. 2. The paper feeding device for a printer according to claim 1, wherein the feed motor is driven to rotate forward or reverse. 3. The paper feed roller is provided with a detected portion as a reference position for starting paper feeding, and a detection portion is provided for detecting the detected portion and transmitting a detection signal to the control portion. The paper feeding device for a printer according to claim 1, wherein the paper feeding device is a printer. 4. A method of controlling a paper feeding device of a printer that feeds paper using the paper feeding device of the printer according to claim 1, wherein the paper feeding control by the control unit is: In the case of color printing, at the time of the first printing with the ink portion of the first color, the paper feed motor is driven based on the detection signal of the detected portion by the detection device to perform line feed of the paper, and at each line feed. The required rotation amount of the paper feed motor is sequentially stored in the storage unit, and when the printing of the first color is finished and the next second color is printed, only the total paper feed amount stored in the storage unit is used. A paper feed motor is reversely rotated to convey the paper to the first line feed position, and the paper feed motor is driven based on each line feed data stored in the storage unit to perform line feed. Control method of paper feeding device. 5. A method of controlling a paper feeding device of a printer that feeds paper using the paper feeding device of the printer according to claim 1, wherein the paper feeding control by the control unit is: In the case of color printing, at the time of the first printing with the ink portion of the first color, the paper feed motor is driven based on the detection signal of the detected portion by the detection device to perform line feed of the paper, and at each line feed. The required rotation amount of the paper feed motor is sequentially stored in the storage unit, and when the printing of the first color is completed and the next second color is printed, the last line of the data stored in the storage unit is stored. A method for controlling a paper feed device of a printer, wherein line feed data required for line feed is sequentially read and line feed is performed by driving the paper feed motor in reverse so as to print from the last line of the paper. 6. A method of controlling a paper feeding device of a printer for feeding paper using the paper feeding device of the printer according to claim 3, wherein the paper feeding control by the control unit is performed when a plurality of pages are printed. , The first page is printed by the paper feed motor based on the detection signal of the detected portion by the detection device when the detected portion which is the reference position of the paper feed formed on the paper feed roller is detected by the detection portion. When the paper feed motor is driven to start line feed, the rotation amount of the paper feed motor required for each line feed is sequentially stored in the storage unit, and when printing the second and subsequent pages, the detected unit is always detected. A method for controlling a paper feed device of a printer, characterized in that printing is started from and the line feed of the paper is performed based on the data stored in the storage section.