JPH11348327A - Method for limiting printing density of printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a decrease in effective print speed of a printing apparatus to a minimum by changing a speed of a shuttle at the print time in accordance with the number of dots of print data when the print data is detected to exceed a regulated value. SOLUTION: A printing control means 1 transfers to a data latch circuit 8 a maximum dot number of data printable by one shuttle at a normal speed. A print data transferred from a host device is received at the printing control means 1, and at the same time, the number of print dots is counted by a print dot number count means 7 and compared by a comparator 9 with a regulated value stored in the data latch circuit 8. When the count value is within the regulated value, the shuttle is driven at the normal speed by a shuttle control means 4 to carry out printing. When the count value exceeds the regulated value, an operation speed of the shuttle is decreased by the shuttle control means 4 so as not to exceed a permissible upper limit of a current capacity of a power source, thereby reducing a consumption current at the printing by one shuttle to carry out the printing. An effective print speed is improved accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing density limiting method for a printing apparatus.

[0002]

2. Description of the Related Art The configuration of a conventional printing apparatus will be described with reference to FIG.

In FIG. 1, reference numeral 11 denotes printing control means, 13 denotes a printing hammer serving as a printing element for printing figures and characters on a dot matrix, 12 denotes hammer driving means for driving the printing hammer, and 15 denotes a plurality of printing hammer. A shuttle mechanism for reciprocating a hammer bank (not shown) on which the hammer 13 is mounted in the row direction; 14, a shuttle control means for driving and controlling the shuttle mechanism; 16, a print dot number counting means; A latch circuit 18 is a comparator.

In the above-described conventional printing apparatus, there is a problem that the power consumption of the hammer becomes large and the power supply cannot be downsized when the print data has a high density. Therefore, control for reducing the power supply is performed.

[0005] During reception of print data before printing, the number of dots of the print data is counted by the print dot number counting means 16. If the number exceeds the specified value, the print data is printed by the first shuttle and the print data is printed by the second shuttle. For example, data is divided into several pieces of data, and printing is performed separately by a plurality of shuttles, so that the current consumption of printing of one shuttle does not exceed the allowable upper limit value of the current capacity of the power supply.
In addition, the specified value is such that the current consumption of printing for one shuttle is:
Set so as not to exceed the allowable upper limit of the current capacity of the power supply.

FIG. 4 shows an example of the timing chart.

In FIG. 4, while receiving the print data of the first line, the number of dots of the data is counted. Since the data does not reach the specified value, printing is performed with one shuttle, and the second line received during the printing of the first line is printed. Since the data exceeds the specified value, printing is performed by dividing the data into two shuttles.

[0008]

In the above prior art,
The number of dots in the print data is counted and divided into a plurality of shuttles to execute the sorting. The print limit specified value for performing the sorting is set to a value that does not exceed the allowable upper limit of the current capacity of the power supply in one shuttle printing.

[0009] However, when the division is performed, 2
In the case of separate printing, the effective printing speed is reduced to 1/2, and in the case of separate printing, the effective printing speed is reduced to 1/4. At this time, there is a problem that the effective printing speed of the printing apparatus may be reduced in the printing of one shuttle during the sorting even though there is a margin to the limit capability of the power supply.

Accordingly, an object of the present invention is to minimize a decrease in the effective printing speed of a printing apparatus by a printing control method that draws out the capacity of a power supply to the limit.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hammerbank equipped with a plurality of printing hammers and printing a plurality of dot rows simultaneously in a process of reciprocating in a row direction, and a reciprocating motion of the hammerbank. A shuttle mechanism, a print dot number counting means for counting the number of dots of print data before printing starts, a comparison means for comparing the print dot number with a predetermined value, and a change in the shuttle moving speed. This is achieved by changing the shuttle speed at the time of printing according to the number of dots of the print data when it is detected that the print data exceeds a specified value.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a control block diagram of a printing apparatus as an example of the present invention, and FIG. 2 shows an example of the printing operation.

In FIG. 1, 1 is a printing control means, 2 is a hammer driving means, 3 is a printing hammer, 4 is a shuttle controlling means, 5 is a shuttle driving means, 6 is a shuttle, 7 is a printing dot number counting means, and 8 is a printing dot number counting means. A data latch circuit 9 for holding a specified value is a comparator.

The print control means 1 transfers the maximum number of dots of data that can be printed by the shuttle at a normal speed to the data latch circuit 8 in one shuttle.

The print data transferred from the host device is received by the print control means 1, the number of print dots is counted by the print dot count means 7, and the count value is stored in the data latch circuit 8 by the comparator 9. If the count value is within the specified value, the shuttle is operated by the shuttle control means 4 at a normal speed to execute printing. Since the specified value is set to a value that does not exceed the allowable upper limit of the current capacity of the power supply when the shuttle operates at the normal speed, the power consumption of the hammer for this printing is the current capacity of the power supply. Is not more than the allowable upper limit.

If the number of print dots of the print data transferred from the host device exceeds a specified value, the print control device 1 reads the count value of the print dot number counting means 7 and makes the speed of the shuttle lower than the normal speed. When the operation is performed at a low speed, the hammer consumption current for one shuttle printing is calculated, and the shuttle control speed is reduced by the shuttle control means 4 so as not to exceed the allowable upper limit value of the current capacity of the power supply. Printing is performed with the current reduced. The speed of the shuttle at this time is set to the highest speed within a range not exceeding the allowable upper limit of the current capacity of the power supply.

FIG. 2 shows an example of a printing operation according to the present invention.

In the first line, the number of print dots is counted simultaneously with the reception of print data. Since the count value has not reached the specified value, the shuttle is operated at the normal speed to execute printing.

At the same time as the printing of the first line, reception of the print data of the second line and counting of the number of print dots are executed. Since the count value has reached the specified value, the count value is read by the print control means 1 and consumption of one shuttle. Printing is performed at a reduced shuttle speed until the current does not exceed the allowable upper limit of the current capacity of the power supply. However, the decrease in printing speed is smaller than in printing by separate printing.

[0021]

As described in detail above, according to the present invention,
The effective printing speed of the printing apparatus can be improved by using the power supply to its limit.

[Brief description of the drawings]

FIG. 1 is a block diagram of a printing apparatus as an example of the present invention.

FIG. 2 is a timing chart illustrating an example of the printing operation of FIG. 1;

FIG. 3 is a block diagram illustrating an example of a conventional printing apparatus.

FIG. 4 is a timing chart of the printing operation of FIG. 3;

[Explanation of symbols]

1 is a printing control means, 2 is a hammer driving means, 3 is a hammer,
4 is a shuttle control means, 5 is a shuttle drive means, 6 is a shuttle mechanism, 7 is a print dot number counting means, 8 is a data latch circuit, and 9 is a comparator.

Claims (1)

[Claims] 1. A hammer bank which carries a plurality of printing hammers and simultaneously prints a plurality of dot rows in a process of reciprocating along a row direction, a shuttle mechanism for reciprocating the hammer bank, and Print dot number counting means for counting the number of dots of the print data, comparison means for comparing the print dot number with a predetermined value, and a shuttle speed control device for changing the shuttle moving speed. A print density limiting method for a printing apparatus, wherein, when it is detected that the print data exceeds a specified value, the speed of the shuttle during printing is changed according to the number of dots of the print data.