JP2000103127A - Printer, printing method, and method for developing image data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer and a print method whereby print image data can be prevented from disappearing even when a logic page length is larger than a physical page length and a print quality can be improved. SOLUTION: A difference between a position of print image data developed earlier and a print position by a print head to a printing recording medium is set to be not larger than an override amount at all times. Before a paper detector detects a lower end of the printing recording medium (No in S704), the development is restricted so that the difference between the development position and print position does not increase to an initial value K of the override amount (a distance between the paper detector and print head, which is a constant value) or larger (S712). Image data to be printed to a next page can be surely prevented from being developed. After the paper detector detects the lower end of the printing recording medium (Yes in S704), printing is carried out while the override amount X (a variable an initial value of which is equal to the K) is calculated (S705 and the followings). The printing is accordingly possible up to a limit of the lower end of the printing recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer and a printing method for developing printing image data prior to printing, such as an ink jet printer and an impact dot printer, and more particularly to such a printer and printing method. Related to the technology for controlling the deployment of a computer.

[0002]

2. Description of the Related Art For example, a serial printer such as an ink jet printer, a thermal transfer printer or an impact dot printer includes a printer controller and a print engine, and performs printing based on print data transmitted from a printer driver on a host computer. The print image data is generated, and the print engine is operated according to the print image data. That is, dots are formed at predetermined positions while the print head is relatively moved (main scanning) with respect to a print recording medium such as recording paper.
Printing is performed by performing a predetermined paper feed (sub-scan) every time the main scanning is completed.

Here, in order to perform printing at a higher speed, print image data relating to a line preceding a line to be actually printed is generated. That is, when the print head is printing a certain line, the data of the line preceding the line related to the current printing is already stored in the image buffer.

FIG. 8 is an explanatory view showing an outline of a serial printer. As shown in FIG. 8 (a), a print recording medium S fed from a tray or the like includes a paper feed roller 100 and a driven roller 101. Is carried into the print engine. When the paper detector 102 detects the upper end of the print recording medium S, the paper discharge roller 103 and the knurled roller 104 start rotating. When the print recording medium S reaches the print head 105, the print head 105 ejects ink droplets at predetermined positions while moving in a direction perpendicular to the paper surface (main scanning direction). When one main scan is completed, the print recording medium S becomes
The sheet is conveyed by a predetermined feed amount to the left in the figure. By repeating the main scanning and the sub-scanning in this manner, printing is performed on the print recording medium S.

As shown in FIG. 8B, since the print head 105 and the paper detector 102 are set apart from each other, when the lower end of the print recording medium S passes through the paper detector 102, the print head 105 105 and paper detector 102
Can still be printed on the print recording medium S by an amount corresponding to the separation distance from the print recording medium S. Thus, the print recording medium S
Is referred to as an override amount. The initial value of the overriding amount for which the physical page length is determined (corresponding to the distance between the print head 105 and the paper detector 102, and the overriding amount decreases each time the paper is fed). The print image data is generated prior to actual printing. That is, the end position iYP0S of the already generated print image data in the sub-scanning direction.
Is the actual print position rYP by the print head 105
It is located before the OS.

[0006]

In the prior art described above, print image data is generated prior to the current printing. However, the length of the page (logical page length) indicated by the print data and the logical length of the page are determined. The length (physical page length) of the print recording medium actually fed may not match. For example, while document data is being generated with A4 size page settings, the printer may print on paper of a size different from A4 size, such as A4 deformed size, legal size,
Paper of B5 size or the like may be set.

FIG. 9 is an explanatory view showing a printing state. In the case where the logical page length is shorter than the physical page length, and as shown in FIG. In this case, even if the image data for printing is developed in advance, no printing trouble occurs. This is because the sheet is discharged as scheduled according to the logical page length specified by the page break command, the number of bands, etc. before the sheet is discharged based on the actual page length. Accordingly, each line indicated by a hatched portion in the drawing is within the print area of the print recording medium.

However, if the logical page length is longer than the physical page length, the print image data is developed first before detecting the timing of actually discharging the paper. there is a possibility. In other words, when the final development position iYPOS of the image data exceeds the override amount, the printing of the last line in the physical page is divided as shown in the two-dot chain line in FIG. The print quality may be degraded due to loss of the expanded print image data. That is, the paper detector 1
The actual length (physical page length) of the print recording medium S cannot be determined until it is detected that the lower end of the print recording medium S has passed through “02”. Therefore, if the print image data of the portion exceeding the physical page length is generated in advance before the detection of the physical page length, the print image data of the portion which exceeds the physical page is generated. Is lost or printing is interrupted. When the print image data is supplied to the print head, the print image data is erased from the image buffer. Therefore, even if the actual printing is not performed normally, the print image data is lost.

For example, when the number of dot forming elements of the print head 105 is about 48 or 64, even if the logical page length is slightly longer than the physical page length, no inconvenience occurs. This is because when the number of dot forming elements is small, printing is performed line by line in one main scan. However, in recent years, in order to further improve the printing speed, for example, a multi-line print head in which a large number of simultaneously printable lines are formed by forming a large number of dot forming elements such as 128 or 144 dots has been developed. Provided. In a printer using a print head capable of simultaneously printing a plurality of lines, if the logical page length exceeds the physical page length, the number of unprinted lines at the lower end side of the print recording medium increases. Quality is greatly reduced.

Further, as described above, in a normal serial printer, the physical page length of the print recording medium S is determined only after the paper detector 102 detects that the lower end of the print recording medium S passes. Thereafter, since it is possible to determine that printing should be performed on the next page, in order to further improve the throughput, it is more necessary to generate printing image data (developing the image data in the image buffer) prior to actual printing. If the printing speed is fast, the image data to be printed on the next page is generated (developed in the image buffer) before the lower end of the printing paper S is detected by the paper detector 102 and the next page can be determined. turn into.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described various problems, and an object of the present invention is to eliminate the problem that print image data is lost even when a logical page length is longer than a physical page length. It is an object of the present invention to provide a printer and a printing method capable of preventing the occurrence of a print error and improving print quality.

[0012]

According to the present invention, in order to achieve the above object, the difference between the position of image data for printing to be developed in advance and the position of printing on a print recording medium by a print head is always determined. It is set to be less than the override amount.

As a result, generation of image data to be printed on the next page (development in the image buffer) does not occur.

That is, in the invention according to the first aspect, the difference between the position of the image data for printing to be developed in advance and the print position on the print recording medium at a certain point in time is always maintained to be equal to or less than the override amount. It is characterized by having done.

According to a second aspect of the present invention, the difference between the position of the printing image data and the printing position is maintained at or below the initial value of the override amount. Further, in the invention according to claim 3, the physical page length of the print recording medium determines the difference between the position of the image data for printing to be developed first and the print position on the print recording medium at a certain point in time. Before, the override amount is maintained at or below the initial value of the override amount, and after the physical page length is determined, the override amount decreasing at each sub-scan of the print recording medium is calculated at a predetermined timing, and the calculated override amount is calculated. It is characterized in that it is maintained below the amount.

Here, the override amount means the length of the printable area left on the print recording medium after the physical page length is determined, and decreases each time the print recording medium is sub-scanned. This is a concept that includes before the physical page length is determined, and the value (initial value) until the physical page length is determined is a fixed amount. Here, according to the first aspect of the present invention, after the lower end of the print recording medium is detected by the paper detector and the physical page length of the print paper is determined, the print image developed in advance is printed. The position of the print data and the length of the printable area of the print recording medium (override amount) are compared for each main scan, so that print image data is not generated beyond the physical page length of the print recording medium.

That is, in the printer according to the fourth aspect of the present invention, the print head performs main scanning based on input print data and performs sub-scanning on a print recording medium to perform predetermined printing. Image data generating means for generating print image data by a predetermined amount prior to printing by main scanning; storage means for storing the generated print image data;
A print control unit that supplies the print image data stored in the storage unit to the print head to perform predetermined main scanning and sub-scanning; a detection unit that detects passage of the print recording medium; Comparing the logical page length indicated by the data and the page length of the print recording medium calculated based on the detection signal from the detection unit, the logical page length exceeds the page length of the print recording medium Determining means for determining whether or not the logical page length is greater than the page length of the print recording medium, according to the page length of the print recording medium. The print image data is generated within the range.

The image data generating means generates print image data by a predetermined amount (for example, one line at a time) before printing. The generated image data is supplied to the print head via the storage unit. The printing control means includes:
Printing is performed by alternately performing the main scan of the print head and the sub-scan of the print recording medium. If the determination unit determines that the logical page length is longer than the actual page length, print image data is generated within a range corresponding to the actual page length.

Here, the logical page length can be detected by, for example, the number of bands per page (the number of main scans) notified from the host computer. Further, the page length of the print recording medium is determined by the amount of override when the detecting means detects the passage of the lower end of the print recording medium (the initial value of the override amount is the separation distance between the detecting means and the print head and is known). It can be obtained by adding the total paper feed amount up to now. If it is determined that the logical page length is longer than the actual page length, advance development of the print image data is permitted within a range corresponding to the actual page length. That is, the image data generating means is controlled so that the data of the portion exceeding the actual page length is not developed first. As a result, when the page length set on the host computer is different from the page length of the actually fed print recording medium, it is possible to prevent unnecessary loss of print image data, and to improve print quality. Can be improved.

Further, as in the printer according to the fifth aspect,
The determination means determines whether or not the end position in the sub-scanning direction of the print image data newly generated by the image data generation means exceeds the lower end of the print recording medium based on the detection signal from the detection means. If the determination unit determines that the end position of the print image data in the sub-scanning direction does not exceed the lower end of the print recording medium, the new print data If the determination unit determines that the end position of the print image data in the sub-scanning direction exceeds the lower end of the print recording medium, the image data for printing stored in the storage unit is permitted. The image data can be printed by the print head and the print recording medium can be discharged.

The image data generating means generates print image data prior to printing, and the generated print image data is stored in the storage means. Here, assuming that the end position of the already generated print image data in the sub-scanning direction is iYPOS and the advance paper feed amount of the image data generating means is y, the end position of the print image data to be newly generated from now on Is iYP0S + y
Becomes If it is determined that the predicted end position exceeds the lower end of the print recording medium, the print image data that has already been stored is printed, and then the print recording medium is discharged. As a result, generation of print image data exceeding the actual print area can be prevented, and data loss can be prevented.

Further, as in the printer according to the sixth aspect,
The print head may be configured to print a plurality of lines in one main scan, and the image data generating unit may generate the print image data line by line prior to printing.

For example, if a large number of dot forming elements such as 128, 144, etc. are formed in a print head, 1
A plurality of lines can be printed in one main scan. Then, the image data generating means generates the printing image data line by line prior to the actual printing. As described above, by using a print head capable of simultaneously printing a plurality of lines, it is possible to prevent unnecessary generation of print image data at the lower end side of the print recording medium, and to efficiently perform printing in units of a plurality of lines. be able to.

According to a seventh aspect of the present invention, in the printing method for performing a predetermined printing by causing a print head to perform main scanning and a printing recording medium to perform sub-scanning based on input print data. Judging whether or not the lower end of the print recording medium being printed is detected by the detecting means provided between the head and the paper feed port; and, when the lower end of the print recording medium is detected, Detecting the maximum in the sub-scanning direction of the printable area left on the print recording medium; and terminating the printable area in the sub-scanning direction of the image data for printing newly generated prior to printing. Determining whether the image is located outside; and if it is determined that the end position is not located outside the printable area, generating the image data for printing. And if it is determined that the end position is outside the printable area, the generation of the print image data is interrupted, and the print image data stored in the storage unit is printed by the print head. Causing the print head to eject the print recording medium when printing by the print head is completed, and generating the interrupted print image data when a new print recording medium is fed. And a step.

Thus, the same operation as that of the printer according to the fourth aspect can be obtained.

[0026] The recording medium according to claim 8 is a program recording medium storing a computer program for controlling a printer having a print head,
An image data generation function of generating print image data by a predetermined amount prior to printing; a storage function of storing the generated print image data in storage means; and storing the stored print image data in the storage unit. A print control function to supply a print head and perform predetermined main scanning and sub-scanning, a detection function to detect passage of the print recording medium through a detection unit, and a detection signal from the detection unit, A determination function for determining whether or not the end position of the newly generated print image data in the sub-scanning direction exceeds the lower end of the print recording medium; If it is determined that the print image data does not exceed the lower end of the print recording medium, generation of the new print image data is permitted, and If it is determined that the end position in the direction exceeds the lower end of the print recording medium, the computer is caused to cause the print head to print the stored print image data and discharge the print recording medium. A program for operation is recorded in a form that can be read and understood by the computer. Here, as the recording medium, various media such as a single floppy disk, hard disk, memory, magnetic tape and the like can be adopted. The present invention is not limited to this. For example, a predetermined program can be remotely downloaded to a printer CPU via a communication line.

By causing the computer of the printer to read the predetermined program, it is possible to obtain the same operation as the printer according to the fourth aspect of the present invention.

In order to achieve the second object, according to a second aspect of the present invention, the difference between the position of the image data for printing to be developed in advance and the printing position of the print recording medium by the print head is always determined. It is set to be less than the override amount.

As a result, the data to be printed on the next page is not expanded before the physical page length is determined.

That is, in the printer according to the ninth aspect, printing is performed by performing main scanning while maintaining the print head at a predetermined position in the sub-scanning direction and sub-scanning the print recording medium based on the input print data. An image data developing means for generating image data for printing prior to printing by the main scan of the print head and expanding the image data to a predetermined position in a logical page length, and developing the image data in the image buffer. The print image data is supplied to the print head to perform the main scanning and the sub-scanning, and a print control unit is provided at a predetermined position in the sub-scanning direction of the printer, and the print recording medium is at a predetermined position. A detector for detecting the arrival, and the printing record based on a detection signal from the detector. Before the physical page length of the medium is calculated, the difference between the development position of the print image data in the logical page length and the current print position on the print recording medium is determined by the print head in the sub-scanning direction. Compared with the interval with the detector, if it is determined that the interval does not exceed the interval, expansion of new print image data is permitted. Means for printing the generated print image data by the print head and prohibiting the development of new print image data until the print image data does not exceed the interval. Further, in the printer according to claim 10, after the physical page length of the print recording medium is calculated based on the detection signal from the detection unit,
Means for determining whether or not the end position of the newly generated print image data in the sub-scanning direction exceeds the lower end of the print recording medium; If it is determined that the end position does not exceed the lower end of the print recording medium, expansion of new print image data is permitted, and the end position of the print image data in the sub-scanning direction is determined by the determination unit. If it is determined that it goes beyond the bottom of the print recording medium,
The printing image data that has already been developed is printed by the print head, and the print recording medium is discharged. In the printer according to the eleventh aspect, the print head is configured to be able to print a plurality of lines in one main scan, and the image data developing unit performs the printing for one line at a time prior to printing. It is characterized by expanding image data.

According to a twelfth aspect of the present invention, there is provided an image data developing method in which a printer develops image data on a buffer based on input print data prior to printing on a print recording medium. Issuing a request to develop a unit of image data, and, if the image data of the predetermined unit is developed in response to the development request, whether the development position of the print recording medium in the sub printing direction exceeds the printing position. Judging whether or not the development position does not exceed the printing position, permitting the development of the image data in the predetermined unit, and if the development position exceeds the printing position, Waiting for the development of the image data of the predetermined unit without permitting the development of the image data.

According to a thirteenth aspect of the present invention, there is provided a recording medium storing a program for causing a printer to develop image data on a buffer based on input print data prior to printing on a print recording medium. A process of issuing a request to develop image data of a given unit, and, if the image data of the predetermined unit is developed in response to the deployment request, whether the developed position of the print recording medium in the sub printing direction exceeds the print position. Processing of determining whether or not the image data is expanded in the predetermined unit if the expansion position does not exceed the printing position, and if the expansion position exceeds the printing position, the predetermined unit Characterized by recording a program which does not permit the image data to be expanded and waits for the expansion of the image data of the predetermined unit. .

[0033]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a functional block diagram schematically showing a main part of a printer to which the present embodiment is applied.

As will be described later, the printer 1
Print head 2, main scanning drive unit 3, sub-scanning drive unit 4, control unit 5, data storage unit 6, and head drive unit 7.
And a paper detector 8. In the print head 2, for example, a predetermined number of nozzles 2A, such as 128 or 144 nozzles, are arranged in a row in the sub-scanning direction (vertical direction in FIG. 1) at a predetermined nozzle interval. Multiple lines can be printed. Each of the nozzles 2A constituting a part of the "dot forming element" discharges a predetermined amount of ink supplied to the pressure generating chamber due to a pressure change due to expansion and contraction of the piezoelectric vibrator. Also, for example,
By generating heat by controlling the heat generated by the heating element,
Ink droplets can also be ejected by pressure fluctuations due to the generation of bubbles. In addition, as a dot forming element,
It is not limited to an ink jet type.

The main scanning drive unit 3 controls the print head 2
For example, it is driven in a predetermined main scanning direction (left-right direction in FIG. 1) with respect to a print recording medium S such as cut paper.
The main scanning drive unit 3 moves the carriage on which the print head 2 is mounted in a predetermined direction by controlling the operation of the carriage motor. The sub-scanning drive unit 4 drives the print recording medium S to be transported in a sub-scanning direction orthogonal to the main scanning direction. The sub-scanning drive unit 4 conveys the print recording medium S taken out of the paper feed tray by a predetermined amount by controlling the operation of the paper feed motor.

The control unit 5 as a “print control unit” controls the driving amount and the driving timing of the main scanning driving unit 3 and the sub-scanning driving unit 4 so that the print head 2 is controlled.
Is moved in the main scanning direction to be located at a predetermined position. Here, the control unit 5 controls the physical page overrun determination unit 1
1 and an image data generation unit 12. Physical page overrun determination section 11 as "determination means"
Is to determine whether or not the end position of the previously generated print image data has exceeded the physical page of the print recording medium. The image data generation unit 12 as an “image data generation unit” performs one
The print image data is generated line by line.

The data storage unit 6 as “storage means”
It comprises a memory for storing print image data. The print image data for each line generated in advance by the image data generation unit 12 is stored in the data storage unit 6, and is supplied to the head drive unit 7 via the data storage unit 6. The head drive unit 7 discharges ink droplets from predetermined nozzles 2A by energizing the print head 2 based on print image data input from the data storage unit 6.

The paper detector 8 as "detecting means" is provided on a paper feed path between the paper feed roller 100 and the print head 2, similarly to the paper detector 102 described above with reference to FIG. The paper detector 8 can be composed of, for example, a photoelectric switch or the like, and can detect the upper end and the lower end of the print recording medium S, respectively.

Next, the operation of this embodiment will be described with reference to FIG. FIG. 2 is a flowchart schematically showing a main part of the printing process, and shows a state after printing is started. In step (hereinafter abbreviated as "S") 1, printing is performed by alternately repeating main scanning and sub-scanning. Next, S2
Then, it is determined whether the printing of the print job has been completed.
When the printing is completed, the determination is “YES” and the process is terminated. When the data to be printed remains, the determination is “NO” and the process proceeds to S3.

In S3, it is determined whether or not a logical page over has occurred. That is, it is determined whether or not to discharge the paper based on the number of bands or a line feed command input from the host computer. If a logical page over occurs, "YE
S ", and skips S4 to S6 to be described later and proceeds to S8. If no logical page crossing has occurred, "N
It is determined as "O" and the process proceeds to S4, where it is determined whether or not the sheet detector 8 has detected the lower end of the print recording medium S. If the lower end of the print recording medium S has not been detected, “NO” is determined, and the process returns to S1 to continue printing.

When printing proceeds and the paper detector 8 detects the lower end of the print recording medium S, "YES" is determined in S4, and the override amount X is obtained in S5. The initial value of the override amount X is determined by the paper detector 8 and the print head 2.
Distance. Next, in S6, it is determined whether or not the difference between the new development position (iYPOS + y) of the print image data and the actual print position rYPOS is equal to or greater than the current override amount X, ie, the newly generated print image data. It is determined whether the end position (iYPOS + y) in the sub-scanning direction has exceeded the printable area. Where y is
A unit for generating print image data in advance,
Image height for one line.

If the print image data does not exceed the printable area even if one line of print image data is newly generated, "NO" is determined, and the routine goes to S7. Then, the developing position of the print image data is advanced by one line (S7), and new print image data is generated (S11). The printing image data generated in S11 is stored in the data storage unit 6, and is supplied to the head driving unit 7 when the print head 2 reaches a predetermined position and printed.

As the printing on the lower end side of the print recording medium S proceeds, the override amount X decreases. When newly generating print image data causes the print image data to exceed the printable area,
S6 is determined as "YES", and generation of new print image data is prohibited. As a result, the printing image data that has already been generated earlier is printed (S
8) The print recording medium S on which printing has been completed is discharged (S
9). Then, a new print recording medium S is carried in from a paper feed tray or the like and set (S10), and generation of print image data is started again (S11). In S11, the S
The print image data of the line determined to be out of the printable area in step 6 is generated. As described above, when the lower end of the print recording medium S is detected (S4), the process proceeds to the lower end side print processing (S5 to S11), and print image data is generated within a range not protruding from the print recording medium S. I have.

According to the present embodiment configured as described above, the following effects can be obtained. First, when it is predicted that the logical page length exceeds the physical page length, the print image data is generated within a range corresponding to the physical page length. Even if the page length is shorter than the logical page length determined by the print setting, printing can be performed appropriately in accordance with the actual page length.

That is, as shown in FIG. 3A, the end position iYPOS of the print image data generated in advance.
Does not exceed the override amount X, the print image data is supplied to the print head 2 and printed at each main scan. Therefore, as shown in FIG. 3B, the last line is not divided, and the print image data of the line is not lost, and appropriate printing can be performed. For example, when printing a worksheet of spreadsheet software, printing an address book, a program list, and the like, items and characters to be printed are important for the user, and the print layout itself is often not particular.
In the present embodiment, printing can be performed properly even when a print recording medium shorter than the set paper size is fed, so that in the case of a print job in which the page length at the time of print setting is not regarded as important, the usability is greatly increased. improves.

Second, in order to determine whether or not the end position iYPOS of the newly generated print image data exceeds the printable area, it is determined whether or not a physical page overrun occurs for each main scan. It can be easily determined.

Third, since a print head 2 capable of simultaneously printing a plurality of lines is employed and print image data is generated in units of one line, printing is performed to the very bottom of the print recording medium while increasing the printing speed. can do.

In the first embodiment, the paper detector 8
After the physical page length of the print recording medium can be determined through the process of detecting that the lower end of the print recording medium S passes, the initial value is the separation distance between the print head and the paper detector. After that, while calculating the override amount X that decreases with each sub-run, the image data to be printed on the next page is generated by comparing with the position of the developed print image data (image (Development in the buffer).

However, in order to further improve the printing throughput, the printing image data is generated (developed in the image buffer) prior to the actual printing in the printer.
If the process proceeds faster, before the lower end of the print recording medium is detected by the paper detector and the next page can be determined, image data to be printed on the next page is generated (developed in the image buffer). Will be done.
In other words, the first embodiment described above cannot deal with the case where the generation of the image data (developing the image data into the image buffer) proceeds faster, and there is a possibility that a situation in which the print quality deteriorates cannot be avoided.

In order to avoid such a situation, the inventor further sets the difference between the developing position and the printing position to be greater than the initial value of the override amount even before the lower end of the print recording medium is detected by the paper detector. Devised to limit deployment so that it does not spread to Hereinafter, a second embodiment of the present invention for achieving this object will be described. First,
FIGS. 4A to 4D show how the above situations to be avoided occur to facilitate understanding of the present embodiment.
This will be described with reference to FIG.

That is, as shown in FIG. 4A, data that originally exceeds the physical page length (the portion surrounded by a dotted line in FIG. 4) is data that should be printed on the next page. As shown in FIG. 4B, when the print head is at the position of YA in the drawing, that is, before the lower end of the print recording medium is detected by the paper detector, the override amount X as in the first embodiment is set. Calculation cannot be started. As shown in FIG. 4 (c), this override amount X is determined only when the print head comes to the position of YB in the drawing, that is, when the lower end of the print recording medium is detected by the paper detector, and thereafter, it is decreased. It is possible to calculate the override amount X as a variable. Therefore, in the case shown in FIG. 4B, the creation and development of image data may proceed more and more,
As shown in the drawing, there is a possibility that the position of the developed data may exceed the lower end of the print recording medium at once. In such a case, as shown in FIG. 4D, the print result becomes an undesired situation in which data (characters and graphics) is cut off.

Therefore, in this embodiment, as shown in FIG. 5, even before the lower end of the print recording medium is detected by the paper detector and the override amount X can be calculated, the position of the developed data (developing) The difference D between the position and the printing position at that time (a variable that increases or decreases according to the progress of the development) is an initial value K of the override amount (this is the separation distance between the print head and the paper detector, Even before the lower end of the print recording medium is detected by the paper detector, it does not exceed the known (ie, constant).

That is, as shown in FIG. 6, when an expansion request is issued (S601), the difference between the expanded data position (expansion position) and the print position at the time is expanded. It is determined whether or not D does not exceed the initial value K of the override amount (S602). If it does not exceed this value, the development is permitted (S603). The process waits until the printing proceeds and the difference D decreases (S604).

FIG. 7 is a flowchart showing a flow of a printing operation before and after the lower end of the print recording medium is detected by the above-described paper detector in the printer according to the second embodiment of the present invention. Also in the present embodiment, after the lower end of the print recording medium is detected by the paper detector,
As in the first embodiment described above, the override amount X
(Variable, the initial value of which is equal to K) is calculated and printing is performed. Therefore, a detailed description of a portion that performs the same processing as that of the first embodiment will be omitted.

In the printing process of the printer according to the second embodiment, after S701 to S703, it is determined whether or not the lower end of the printing paper (recording medium) is detected (S704).
When this lower end is not detected (No in S704)
In [corresponding to the case shown in FIG. 4B], the difference between the developed position and the printing position [corresponding to the difference D (variable) shown in FIG. 5] is equal to or less than the initial value K (constant) of the override amount. It is determined whether or not this is the case (S712). If the difference between the development position and the print position is not equal to or less than the initial value K (constant) of the override amount (No in S712), the printing proceeds, that is, S
The loop from 701 to S704 is repeated. On the other hand, the difference between the development position and the printing position is the initial value K (constant) of the override amount.
If it is below (Yes in S712), an image corresponding to the head height is developed (S707), and new image data is also generated (S711).

As described above, in the printer according to the second embodiment, before the lower end of the print recording medium is detected by the paper detector, the difference between the developing position and the printing position is prevented from spreading beyond the initial value of the override amount. Therefore, it is possible to reliably prevent the image data to be expanded on the next page from being expanded. After the lower end of the print recording medium is detected by the paper detector, the override amount X (variable, the initial value of which is K, as in the first embodiment).
) Is calculated, the printing can be performed up to the very bottom of the print recording medium.

As described above, the present invention has been described with respect to the specific embodiments. However, the present invention is not limited to these, and is applicable to other embodiments within the scope described in the claims. For example, when the physical page length of the print recording medium S is determined by the detection of the lower end, the expandable position iYPOS (max) of the print image data is calculated, and the expandable position iYPOS (ma) is calculated.
The configuration may be such that generation of print image data is permitted until x) is reached.

Further, for example, a data transfer control unit for controlling the transfer of the print image data is provided between the data storage unit 6 and the head drive unit 7 so that the data transfer control unit does not protrude from the printable area of the print recording medium S. It is also possible to configure so that only the print image data is input to the head drive unit 6.

Further, in the above-described second embodiment, after the lower end of the print recording medium is detected by the paper detector,
As in the first embodiment, printing is performed while calculating the override amount X (variable). However, regardless of whether the lower end of the print recording medium is detected or not, the difference D between the developed position and the printed position is determined.
The expansion may be limited so that the (variable) does not spread beyond the initial value K (constant value) of the override amount.
In this case, it is difficult to print to the last minute, but it is possible to avoid a situation in which the printing result is such that data (characters and graphics) is cut off.

[0060]

As described above, according to the printer and the printing method of the present invention, even if the actual page length is shorter than the logical page length indicated by the print data, the range of the print recording medium can be reduced. It is possible to perform appropriate printing within the printer, maintain print quality, and improve usability.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a printer according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a print processing operation in the printer according to the first embodiment of the present invention.

FIGS. 3A and 3B are explanatory diagrams showing a relationship between generation of print image data and a print result in the printer according to the first embodiment of the present invention, and FIG. FIG. 3B shows the relationship with the override.
Indicates a print result.

FIG. 4 is a diagram for explaining the reason why a situation in which print quality deteriorates due to advance development of image data even before the lower end of a print recording medium is detected by a paper detector, and FIG. Expansion of data that exceeds the target page length,
4B shows a state before the lower end of the print recording medium is detected by the sheet detector, and FIG. 4C shows a state before the lower end of the print recording medium is detected by the sheet detector. Is
The states in which data (characters and figures) are cut off as a printing result are shown respectively.

FIG. 5 is a diagram for explaining a relationship between a position of expanded data and a print position according to the second embodiment of the present invention.

FIG. 6 is an expansion (suppression) in the second embodiment of the present invention.
It is a flowchart which shows a process.

FIG. 7 is a flowchart illustrating a print processing operation in a printer according to a second embodiment of the present invention.

8A and 8B are explanatory diagrams illustrating an outline of a print engine. FIG. 8A illustrates a state when a print recording medium is supplied.
(B) shows the time when the lower end of the print recording medium is detected by the paper detector.

FIGS. 9A and 9B are explanatory diagrams showing a print result according to the related art. FIG. 9A shows a case where the logical page length is shorter than or equal to the physical page length, and FIG. The case where the length is longer than the physical page length is shown.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printer 2 Print head 3 Main scanning drive part 4 Sub-scanning drive part 5 Control part 6 Data storage part 7 Head drive part 8 Paper detector 11 Physical page crossing judgment part 12 Image data generation part

Claims (13)

[Claims] 2. A printer according to claim 1, wherein a difference between a position of the printing image data to be developed in advance and a printing position on a print recording medium at a certain point in time is always kept to be equal to or less than an override amount. 2. A printer according to claim 1, wherein a difference between a position of the image data for printing to be developed in advance and a printing position on a print recording medium at a certain point in time is kept equal to or less than an initial value of an override amount. 3. A difference between a position of image data for printing to be developed in advance and a print position on a print recording medium at a certain point in time is determined by an override amount before the physical page length of the print recording medium is determined. After the physical page length is determined, the override amount is decreased at every sub-scan of the print recording medium, and is calculated at a predetermined timing, and is maintained at or below the calculated override amount. A printer characterized in that: 4. A printer for performing printing by main-scanning a print head and sub-scanning a print recording medium based on input print data, wherein a predetermined amount is set in advance of printing by the main scan of the print head. Image data generating means for generating print image data; storage means for storing the generated print image data; supplying the print image data stored in the storage means to the print head; Print control means for performing scanning and sub-scanning, detection means for detecting that the print recording medium has reached a predetermined position, based on a logical page length indicated by the print data and a detection signal from the detection means The logical page length is compared with the physical page length of the print recording medium calculated by Determining means for determining whether the logical page length is longer than the physical page length if the logical page length is determined to be greater than the physical page length. A printer for generating the print image data within a range defined by the printer. 5. The printer according to claim 4, wherein the determination unit is configured to perform a determination based on a detection signal from the detection unit.
It is determined whether the end position in the sub-scanning direction of the print image data newly generated by the image data generating means exceeds the lower end of the print recording medium, and the sub-scanning of the print image data is performed by the determining means. When it is determined that the end position in the direction does not exceed the lower end of the print recording medium, generation of new print image data by the image data generation unit is permitted, and the determination unit outputs the print image data. If it is determined that the end position in the sub-scanning direction exceeds the lower end of the print recording medium, the print head prints the print image data stored in the storage means and discharges the print recording medium. A printer characterized in that: 6. The printer according to claim 5, wherein the print head is configured to be able to print a plurality of lines in one main scan, and the image data generating unit is configured to print the lines one by one prior to printing. A printer for generating print image data. 7. A printing method for performing predetermined printing by causing a print head to perform main scanning and a print recording medium to perform sub-scanning based on input print data,
Determining whether the lower end of the print recording medium being printed is detected by the detecting means provided between the print head and the paper feed port; and Detecting the length of the printable area left on the print recording medium in the sub-scanning direction; and determining the end position in the sub-scanning direction of the printing image data newly generated prior to printing. Determining whether or not located outside the area, and if it is determined that the end position is not located outside the printable area,
Generating the print image data, and, if it is determined that the end position is located outside the printable area, interrupts the generation of the print image data and stores the print image data stored in the storage unit. Printing data by the print head; ejecting the print recording medium when printing by the print head is completed; and interrupting the printing when a new print recording medium is fed. Generating printing image data. 8. A process for generating print image data by a predetermined amount prior to printing on a recording medium on which a computer-readable program for controlling a printer having a print head is recorded; Storing the print image data in the storage unit, supplying the stored print image data to the print head to perform predetermined main scanning and sub-scanning, and performing the print recording via the detection unit. Based on a process of detecting passage of a medium and a detection signal from the detection unit,
Processing for determining whether the end position of the newly generated print image data in the sub-scanning direction exceeds the lower end of the print recording medium; and determining whether the end position of the print image data in the sub-scan direction is If it is determined that the print image data does not exceed the lower end of the print recording medium, generation of the new print image data is permitted, and the end position of the print image data in the sub-scanning direction exceeds the lower end of the print recording medium. And determining that the stored print image data is printed by the print head and ejecting the print recording medium. 9. A printer that performs main scanning and sub-scanning of a print recording medium while maintaining a print head at a predetermined position in the sub-scanning direction based on input print data, and performs printing by sub-scanning the print head. Means for generating image data for printing prior to printing by main scanning and expanding the image data to a predetermined position in the logical page length in an image buffer; and A print control unit that supplies a print head to perform the main scanning and the sub-scanning, and a detector that is provided at a predetermined position in the sub-scanning direction of the printer and detects that a print recording medium has reached a predetermined position. Calculating a physical page length of the print recording medium based on a detection signal from the detection unit Before the printing, the difference between the development position of the printing image data in the logical page length and the current printing position on the print recording medium is compared with the distance between the print head and the detector in the sub-scanning direction. If it is determined that the interval is not exceeded, the development of new print image data is permitted. If it is determined that the interval is exceeded, the already expanded print image data is printed. Means for prohibiting the development of new print image data until printing is performed by the head and the interval does not exceed the interval. 10. The printer according to claim 9, further comprising: after calculating a physical page length of the print recording medium based on a detection signal from the detection unit, newly generating print image data. Means for determining whether or not the end position of the print image data in the sub-scanning direction exceeds the lower end of the print recording medium. If it is determined that the print image data does not exceed the limit, the development of new print image data is permitted, and the determination unit determines that the end position of the print image data in the sub-scanning direction exceeds the lower end of the print recording medium. A printer that prints the already developed print image data by the print head and discharges the print recording medium. 11. The printer according to claim 10, wherein
A printer, wherein the print head is configured to print a plurality of lines in one main scan, and the image data developing unit expands the print image data line by line prior to printing. . 12. An image data developing method in which a printer develops image data on a buffer based on input print data prior to printing on a print recording medium. Issuing, and, when the image data of the predetermined unit is expanded in response to the expansion request, determining whether an expansion position of the print recording medium in the sub-movement direction exceeds a print position; If the development position does not exceed the printing position, the development of the image data of the predetermined unit is permitted.If the development position exceeds the printing position, the development of the image data of the predetermined unit is not permitted. Waiting for the expansion of the image data in the predetermined unit. 13. A recording medium storing a program for causing a printer to develop image data on a buffer based on input print data prior to printing on a print recording medium, wherein a request for developing image data in a predetermined unit is provided. And a process of determining whether the development position of the print recording medium in the sub-movement direction exceeds the printing position when the image data of the predetermined unit is developed in response to the development request, If the development position does not exceed the printing position, the expansion of the image data of the predetermined unit is permitted, and if the development position exceeds the printing position, the expansion of the image data of the predetermined unit is permitted. Recording a program having a process of waiting for expansion of the image data of the predetermined unit.