JPH0577452A - Printer - Google Patents

Abstract

(57) [Abstract] [Purpose] In a printer that performs printing by driving a plurality of printing units in one printing scan, by performing a printing control method that makes full use of the capability of the printing unit driving power supply, It provides the maximum throughput available from the drive power capability. [Structure] Print data is transferred from a RAM to a head driver at a print timing 401 (402). The printing bit and the non-printing bit are distinguished (403), it is judged whether or not all the data has been printed (409), and printing is prepared. Further, the print head is energized (404), it is judged whether the printing is completed (405), and when it is not completed, the drive voltage is judged (407). At that time, the number of simultaneously driven printing pins is increased or decreased depending on the fluctuation of the driving voltage (412, 41
4).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print control method in a printer that drives a plurality of printing means to perform printing in one print scan.

[0002]

2. Description of the Related Art In a printer that prints by driving a plurality of printing means in one printing scan, usually, in order to improve printing quality and printing speed, many printing means, for example, printing pins of an impact printer. , A print head having a print nozzle of an inkjet printer and a heating element of a thermal printer.

Since print data is not selected and sent so that the printing means are not driven at the same time, the power source capacity or the like should be prepared in accordance with the worst driving state, or the printing means should be turned on. Either method is adopted, which is to detect and deal with a state where driving is not possible.

In the former method, the power source capacity usually has to be made extremely large, so that the latter method is often used. There are many methods for detecting and dealing with a situation where the printing means cannot be driven.

In such a method, first, in order to detect whether or not the printing means cannot be driven, the driving power supply voltage of the printing means is monitored during printing, or the print image data is verified before printing. Then, the possibility of driving power supply voltage drop is predicted.

As a result, when it is determined that the printing means cannot be driven during printing, the printing is temporarily stopped, the printing speed of the remaining printing is reduced, or the printing means to be driven at the same time is determined and the remaining printing is performed. Split the printing of multiple print scans, or
The repetition frequency of the printing unit is reduced to divide the remaining printing into a plurality of predetermined print scans to reduce the power consumption of the printing unit to a predetermined value or less and continue printing.

Further, before printing, the print image data is verified to investigate the possibility of a driving power supply voltage drop. As a result, if it is expected that the printing means cannot be driven during printing, the power consumption of the printing means will be reduced. The printing is divided into a plurality of small, predetermined print scans in some way to start printing, or a predetermined printing speed with low power consumption of the printing unit is selected and printing is started.

[0008]

SUMMARY OF THE INVENTION In such a system,
Dealing with print data that cannot drive the printing unit is usually sufficiently effective, and can contribute to a reduction in the power supply capacity of the printer.

However, printers which drive a plurality of printing means to perform printing have come to use a print head having more printing means in order to further improve printing quality and printing speed. In addition, due to the development of computers and their applications, print data has come to be sent to a printer by mixing text printing with a duty of about 10% and high-density graphic printing. Therefore, it is necessary to drive printing means. Electric power has become more and more dependent on print data.

In such a state, the above-mentioned conventional technique is still insufficient, and when it is judged that the printing means cannot be driven during printing, or when the printing means cannot be driven before printing. In the expected case, the problem is that the ability of the printing means driving power supply cannot be fully utilized in order to start or restart printing with a fixed printing speed or a fixed number of printing scans. ..

Therefore, the present invention solves such a problem, and an object of the present invention is, in a printer that drives a plurality of printing means in one printing scan to perform printing, the capability of a printing means driving power supply. It is to provide a print control method that makes full use of the above.

[0012]

The printer of the present invention has the function of limiting the maximum number of driven printing means,
Drive limiting means capable of changing the maximum value to be limited, drive power source voltage detecting means capable of recognizing a power source voltage for driving the printing means, and existence and position of unprinted data in one printing scan And remaining data recognition means capable of detecting

[0013]

According to the above configuration of the present invention, in a printer that drives a plurality of printing means to perform printing in one print scan, the maximum throughput obtained from the capacity of the printing means driving power supply can be realized. is there.

[0014]

1 is a block diagram showing the construction of a printer in an embodiment of the present invention. First, a description will be given along with a data flow from a general configuration part of the serial printer.

The data transferred through the I / F cable (117) connected to the host computer is I / F.
RAM (110) after being received by the means (104) and processed by the CPU and its surroundings (105).
Is stored as a print image in. The operation of the CPU (105) follows a program stored in the ROM (109). The character pattern is also stored in the ROM (109) and is used to convert the character code into the character pattern as needed. ROM (109), RAM (11
0), and the printhead driver (107) is connected to the bus (1
18) connected to the CPU (105) to exchange information.

The print image data stored in the RAM (110) is sequentially read in synchronization with the movement of the carriage during printing, transferred to the print head driver (107), and at the print timing, the print head (108). )
Drive. The carriage movement is controlled by the CR motor driver (111) controlled by the CPU.
This is performed by driving the motor (112). Similarly, the paper feed is the PF motor driver (11
This is performed by driving the PF motor (114) through 3).

The sensor (115) is provided to detect the state of the paper and the like, and the operation panel (116) is provided to display and operate the operator.

The drive power source (103) is connected to the print head (10).
8), CR motor (112), and PF motor (11
4) A power supply for driving the A / D converter (1
02) and the reference voltage (101) can be monitored by the voltage monitoring means, and the result is transmitted to the CPU (105).

The structural feature of the present invention is that the number of pins for which the print head driver (107) permits simultaneous driving is controlled by the CPU.
It can be changed by the control of (105), and A / D
This is the point that the voltage of the drive power source (103) can be monitored by the CPU (105) by the voltage monitoring means including the converter (102) and the reference voltage (101).

FIG. 2 is a block diagram showing the configuration of a 24-pin print head driver capable of changing the number of drive pins of the printer according to the embodiment of the present invention. In other words, the print head driver (107) and the print head (10) in FIG.
FIG. 8 is a block diagram showing in detail the part (8).

An 8-bit print data mask register (202) and an 8-bit AND gate (203) are provided to control the number of pins for which simultaneous driving is permitted.
Image data to be printed is sent through the bus (201)
4 pins are transferred in 3 bytes. The transferred 3-byte print data passes through the AND gate (203) and is distributed and latched by the print data latches 1 to 3 (204 to 6). The timing signal of the latch for this distribution, the print data latch clocks 1 to 3 (207 to
9) is a ternary counter (21) for counting and distributing the print data latch signal (213) given from the CPU.
6).

The print image data for 24 pins which has been latched is given to the print head driver (210), and C
Energization enable signal (21 controlled by PU
It is used to selectively drive the print pins of the print head (108) according to the timing of 4).

The contents of the print data mask register (202) are rewritten by latching the 8-bit data of the bus (201) output from the CPU by the mask data latch signal (212). Since the output of the print data mask register (202), the mask data (215) and the print image data of 3 bytes are subjected to a logical product operation in each bit in the AND gate (203),
The print data is masked by the content of the print data mask register (202) and printed.

FIG. 3 is a block diagram of a print data mask register for controlling the print pin group of the print head driver capable of changing the number of drive pins of the printer according to the embodiment of the present invention, and controlling the permission and prohibition of the drive of each print pin group. It is a figure which shows an assignment. The same thing can be shown by the relationship between the contents of the print data mask register and the print pins for which driving is permitted, as follows. X indicates prohibition, and ○ indicates permission.

Print pin number Mask register contents (hex) 00 01 03 07 0F 1F 3F 7F FF (302) 1, 9, 17 × × × × × × × × ○ 2, 10, 18 × × × × × × × × ○ ○ 3, 11, 19 × × × × × × × ○ ○ ○ 4, 12, 20 × × × × × ○ ○ ○ ○ 5, 13, 21 × × × × ○ ○ ○ ○ ○ 6, 14, 22 × × × ○ ○ ○ ○ ○ ○ 7, 15, 23 × × ○ ○ ○ ○ ○ ○ ○ 8, 16, 24 × ○ ○ ○ ○ ○ ○ ○ ○ As can be seen from FIG. ) And the name of the print pin group (303), And The relationship between the contents of the print data mask register and the number of print pins permitted to be driven is shown below.

Contents of mask register Simultaneous drive enable pin number 00h 0 pin 01h 3 pin 03h 6 pin 07h 9 pin 0Fh 12 pin 1Fh 15 pin 3Fh 18 pin 7Fh 21 pin FFh 24 pin In this way, the contents of the print data mask register The maximum number of simultaneously driven pins of the print head can be limited.

FIG. 4 is a flow chart showing an outline of the operation at the print timing of the printer in the embodiment of the present invention.

At the print timing (401), 3 bytes of print data are transferred from the RAM to the head driver (4
02) The print data is now latched after being limited by the contents of the print data mask register.

Next, the bit of the image data to be printed on the RAM is cleared to "0" (403). CP
Since U recognizes the contents written in the print data mask register, it is possible to distinguish the unprinted bits and the printed bits accordingly. here,
By selectively clearing the bits to be printed to "0", when the printing operation (printing pass) that is currently printing does not print all the data on one line, the next printing pass It prevents the same dot from being printed redundantly.

The process (409) for estimating the printed portion is to judge whether or not all the data of one line has been printed in the print pass currently being printed, and if the printing is not finished yet, , It is performed to determine at which position to start the next print pass and to what extent the print needs to be performed.

When the print head is energized (404), driving of the print head is started.

The judgment of the end of printing (405) is to judge whether the energization of the print head at present is at the last print position in the required print range, and if it is the last print timing, the print end is judged. EXIT to perform processing (4
06).

The drive voltage determination (407) recognizes the current drive power supply voltage, and determines whether it is a sufficiently high voltage, a slight drop, or an intermediate value. as a result,
If the voltage is an intermediate voltage (408), no processing is performed, but if the voltage drops (411), the content of the print data mask register is changed to reduce the number of simultaneously driven pins (412). This change is to reduce the number of "1" bits in the print data mask register by one. vice versa,
If the voltage is sufficiently high (413), the contents of the print data mask register are changed to increase the number of simultaneously driven pins (414). This change is to increase the number of "1" bits in the print data mask register by one.

FIG. 5 is a flow chart showing details of the operation at the print timing of the printer in the embodiment of the present invention. In particular, the processing (409) for estimating the printed portion in FIG. 4 is described in detail.

In this process, after the process (503) of clearing the data on the RAM of the print pin that is not masked by the print data mask register is performed, the data on the RAM is printed with a bit "1", that is, printed. The process starts with determining whether there is any image data left (515).

If the "1" bit does not exist, nothing is done, but if it does exist, it is the first unprinted data since the start of the print pass, in other words, the RAM data that was previously cleared. It is determined whether or not there is an unprinted portion of "1" (516), and if it is the first unprinted data, the current printing position is set to the pointer indicating the existence position of the first unprinted data. Remember (51
9). Furthermore, if there is a "1" bit, regardless of whether it is the first unprinted data since it started its printing pass, a pointer indicating the existence position of the last unprinted data, The current print position is stored (520). From the contents of these two pointers, it is possible to judge whether all the print image data has been printed after the end of the current print pass, or if not, what range.

FIG. 6 is a diagram showing the relationship between the change in the drive voltage of the print head and the print pin groups for which printing is permitted in the first pass printing during the one-line printing operation of the printer according to the embodiment of the present invention. is there.

Printing is started from the beginning of the line (602), printing is allowed for all pins (24 pins) for a while, but the driving voltage (607) begins to drop and finally the threshold voltage 2 (614). ) Is reached (608). When the threshold voltage 2 (614) is reached, it is determined that the drive voltage is declining, so the contents of the print data mask register are rewritten so that 3 pins of the 8n + 1 pin group are prohibited from printing, and the print head mask Continue printing with reduced power consumption.

As a result, even if the drive voltage is temporarily restored, it starts to drop again and the threshold voltage 2 (61
When it reaches 4) (609), it is determined that the driving voltage is declining, and the content of the print data mask register is further 8
3 pins of the n + 2 pin group are rewritten so that printing is prohibited, and power consumption of the print head is further reduced to continue printing.

However, when the drive voltage recovers during printing and rises to the threshold voltage 1 (613) (61
1) The drive voltage is judged to be sufficiently high, and the contents of the print data mask register are rewritten in the direction to allow printing of one more print pin group than the present, increasing the power consumption of the print head and increasing the number of print pins. Use, try to print.

By continuing this control, it is possible to drive the print pin by maximizing the capability of the drive voltage power supply.

The end of printing of the first print pass in the printing of one line is the last position of the print image data of one line (605). The part that has been printed by this printing pass is indicated by the print-permitted print pin group (604), and the part that is not print-permitted for power consumption adjustment due to voltage drop is masked print pin group (603). Indicated by.

Here, the position (61) where the first unprinted data remains in the print position pointer storage area is stored.
From 6) and the position (617) where there is the last unprinted data, it is judged that not all of the print image data of one line has been printed in this print pass, and the next print pass is activated. This description is detailed in FIG.

FIG. 7 is a flow chart showing a process that must be additionally performed in order to perform the control of the present invention before the printer in the embodiment of the present invention starts the one-line printing operation. Prior to the activation of the first print pass for printing one line, if the print image is ready in RAM and printing of the previous line is completed, printing is permitted (70
1), the print start position and the end position are set (702), the print position pointer is set (703), and the print position pointer storage area for determining whether printing is left (70) is cleared.
4) The print data mask register is set (705), and then the print start process such as mechanism control is started (706).

In this case, the printing start position is the beginning of the printing image and the printing ending position is the end of the printing image because the printing of all printing images is not completed (70
2). The print position pointer is reset to the print start position (703), and the print position pointer storage area for determining whether printing is left may be set to a certain value such as "0" that the print position pointer cannot take (704). ). Since the print data mask register is initially enabled for all pins, FF
Must be set to h (705).

FIG. 8 is a flow chart showing a process which must be additionally performed in order to carry out the control of the present invention before starting the printing of the next line in the printing operation of the printer in the embodiment of the present invention. is there.

The difference from the process performed prior to the activation of the first print pass of the printing of one line is that it must be performed at the beginning of the process to determine whether all the print images have been printed (803). That is, the print start position and the print end position are performed according to the print position pointer storage indicating the unprinted portion (802, 805).

When the printing of the Nth pass is completed (80
1) Whether or not the line has been completely printed is judged from the position of the first unprinted data and the position of the last unprinted data left in the print position pointer storage area. If the position where the first unprinted data remains and the position where the last unprinted data remains are both cleared and have not changed, all the print image data on the RAM will be "0". The printing of the line ends (804).

When the printing of one line is not completed, the printing start position and the ending position are set (802, 805) and the preparation for starting the printing pass of the (N + 1) th pass is started. If the print direction (CR moving direction) of the N + 1th pass is the same as that of the Nth pass, the print start position is set to the position where there is the first unprinted data in the Nth pass (802) and the print end position. Is
At the N-th pass, the last unprinted data is set at a position (802). If the print direction of the (N + 1) th pass is opposite to that of the Nth pass, the print start position is set to the position where the last unprinted data exists in the Nth pass, and the print end position is
It may be set at the position where the first unprinted data exists in the Nth pass.

FIG. 9 shows the print start position, the end position, the change in the drive voltage of the print head and the print pins for which printing is permitted in the second pass printing during the one-line printing operation of the printer according to the embodiment of the present invention. It is the figure which showed the relationship with a group. In the same manner as described with reference to FIG. 6, while monitoring the driving power supply voltage, the contents of the print data mask register are rewritten and printing is performed while adjusting the power consumption of the print head. The second pass is different in that the print range is narrower than that in the first pass.

FIG. 10 shows the print start position, the end position, the change in the drive voltage of the print head, and the print pin for which printing is permitted in the third pass printing during the one-line printing operation of the printer according to the embodiment of the present invention. It is the figure which showed the relationship with a group. Proceed with printing in the same way as the 1st and 2nd passes, and 3
At the pass, all the images on one line have been printed.

[0052]

As described above, according to the present invention, 1
In a printer that performs printing by driving a plurality of printing units in one printing scan, it is possible to provide a printer with a required throughput with a minimum required printing unit driving power supply.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing a configuration of a print head driver capable of changing the number of drive pins of the printer according to the embodiment of the present invention.

FIG. 3 shows print pin grouping of print head drivers capable of changing the number of drive pins of a printer and bit assignment of a print data mask register for controlling permission / prohibition of driving of each print pin group according to an embodiment of the present invention. It is a figure.

FIG. 4 is a flowchart showing an outline of an operation at a print timing of the printer in the embodiment of the present invention.

FIG. 5 is a flowchart showing details of the operation at the print timing of the printer in the embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a change in the drive voltage of the print head and a print pin group for which printing is permitted in the first pass printing during the one-line printing operation of the printer according to the embodiment of the present invention.

FIG. 7 is a flowchart showing a process that must be additionally performed to perform the control of the present invention before the printer according to the embodiment of the present invention starts the one-line printing operation.

FIG. 8 is a flowchart showing a process that must be additionally performed to perform control of the present invention before starting printing of the next line in the printing operation of the printer according to the embodiment of the present invention.

FIG. 9 illustrates a print start position, a print end position, a change in the drive voltage of the print head, and a print pin group for which printing is permitted in the second pass printing during the one-line printing operation of the printer according to the embodiment of the present invention. It is the figure which showed the relationship.

FIG. 10 is a print start position in the third pass printing during one-line printing operation of the printer according to the embodiment of the invention.
FIG. 6 is a diagram showing a relationship between an end position, a change in drive voltage of the print head, and a print pin group for which printing is permitted.

[Explanation of symbols]

 103 drive power supply 108 print head 210 print head driver

Claims (1)

[Claims] 1. A drive limiting unit having a function of limiting the maximum value of the number of driven printing units and a function of changing the maximum value, and recognizing a power supply voltage for driving the printing unit. Drive power supply voltage detection means for performing, and the presence of unprinted data in one print scan,
A remaining data recognition means for detecting the position of the data, and a printer.