GB2202662A

GB2202662A - Printers

Info

Publication number: GB2202662A
Application number: GB08803691A
Authority: GB
Inventors: Satoru Tsukihara; Yoshihisa Kondo
Original assignee: Alps Electric Co Ltd
Current assignee: Alps Alpine Co Ltd
Priority date: 1987-02-23
Filing date: 1988-02-17
Publication date: 1988-09-28
Anticipated expiration: 2008-02-17
Also published as: JPS63205256A; GB2202662B; GB8803691D0

Abstract

A printer (1) includes buffer memory (5) for temporarily storing printing data to be fed, and a print controller (2) for feeding the stored printing data to a printing mechanism (7) to print when the ratio of the capacity of the stored printing data to the total storage capacity of the buffer memory reaches a set value or when an independent printing command is generated, thus improving printing efficiency and saving energy and power. <IMAGE>

Description

PR INTER The present invention relates to printers.

Printers used as output units include wire dot printers, thermal transfer printers, thermal sensitive sheet printers, ink jet printers, laser printers and electrophotographic printers.

These printers are controlled by a host computer to print accurately and clearly at a high speed. More specifically, the host computer generates printing data having a content for printing as predetermined. The printer which receives this printing data processes this data and in response to the data, operates a printing mechanism when necessary to print, on a sheet.

Such printers which process input data from a host computer have the following disadvantages.

The printing data fed from the host computer is not continuous. For example, if a short printing data group which has a content of printing in a short time is fed, a long blank time interval thereafter exists, and the short printing data group is again fed, and this operation is sometimes repeated.

When printing in response to such discrete amounts of printing data, the printing mechanism is started, ordinarily printed and stopped repeatedly at every printing data group and this involves a complicated control of the printing operation. In the printing mechanism to initiate the drivers of drive motors at the correct starting time, a rising time is required, and large power is consumed. When the printing mechanism is lifted in response to every printing data group as in the conventional printer, the total printing time is increased and power consumption is also increased.

In the printer described above, drawbacks also occur when a carriage for driving a print head has to be hunted, a sheet to be printed is wasted by discharge or a sheet is jammed. In such a case, the printing result is entirely lost. In order to eliminate such drawbacks, it is necessary to always monitor when each drawback occurs, and immediately to stop the printing operation when the drawback occurs and then to correct it.

However, when printing data is fed in discrete groups as desribed above, it is wasteful to always monitor the printing state by an operator near the printer.

Accordingly, it is an object of the invention to provide an improved printer. The printer to be described is arranged to avoid the above mentioned drawbacks in that it temporarily stores printing data fed to the printer, and then prints continuously the printing data stored when the capacity of the stored printing data reaches a pretedermined value thereby to improve the printing effeciency and to save energy and power.

According to the present invention, there is provided a printer having a printing mechanism for printing in response to printing data comprising a buffer memory for temporarily storing printing data to be fed, and a print controller for feeding the stored printing data to the printing mechanism to print when the ratio of amount of stored printing data to the total storage capacity of the buffer memory reaches at a set value or when an independent printing command is generated.

Thus, the printing data fed from a host computer is temporarily stored in a buffer memory.

When the ratio of the printing data stored to the total storage capacity of the buffer memory reaches the set value, the print controller feeds all the stored printing data to the printing mechanism, which, in turn, prints in response to the printing data received by the printing mechanism, as desired.

The print controller also feeds the stored printing data to the printing mechanism to print when an independent printing command is fed even when the stored printing data does reach set value.

A printer embodying the present invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings in which: Fig. 1 is a block diagram of a printer embodying the invention; Fig. 2 is a chart showing the storage capacity of printing data by a buffer memory during each stage of printing operation; Fig. 3 is a flowchart describing the printing operation; and Fig. 4 is a flowchart of the printing operation when printing data is interrupted during reception.

The printer 1 shown in Figure 1 has a print controller 2 for controlling the entire printing operation. The print controller 2 is connected through an interface 3 to a host computer (not shown) to receive printing data fed from a host computer.

The print controller further has a ROM 4 and a buffer memoray 5. The print controller 2 is operated according to a program stored in the ROM 4. The buffer memory 5 temporarily stores printing data received by the print controller 2, and in response to a command from the print controller 2 delivers the stored printing data to the print controller 2. A printing mechanism 7 which receives printing data through a driver 6 from the print controller 2 and prints the content of the printing data on a sheet (not shown), is also connected to the print controller 2. The contents of the program for specifying the operation for feeding the printing data to the printing mechanism 7 by the print controller 2 of the programs stored in the RON 4 includes two directions.The first direction is that the printing data is stored in the buffer memory 5 until the capacity of the printing data received by the print controller 2 and then stored in the buffer memory 5 reaches a set fraction of the entire storage capacity of the buffer memory 5, when the capacity of the printing data reaches this set fraction, the printing data stored in the buffer memory 5 is fed to the printing mechanism 7 to start printing. The second, direction is that, when an independent print command is generated from the print controller 2 in case of requiring printing irrespective of the stored capacity of the printing data in the buffer memory 5, the printing data currently stored in the buffer memory 5 is fed to the printing mechanism 7 to start printing.

The operation of the printer will now be described in more detail with reference to Figs. 2 to 4.

When the quantity of printing data stored in the buffer memory 5 reaches 75% of the storage capacity of the buffer memory 5 as shown in Figs.

2(I) to (III), (particularly see Fig. 2(II), the printing operation is started.

The printing operation of the printer 1 occurs as follows: First, the print controller 2 receives the printing data fed through the interface 3 from the host computer, and temporarily feeds to, and stores the printing data in the buffer memory 5.

Then, the print controller 2 operates according to the flowchart in Fig. 3 to print the data. More specifically, when the printer is started, a switch (not shown) for generating an independent print command should be turned ON.

Whether this switch is turned ON or not is judged in step ST1. If the answer to the question of whether or not the switch is turned ON is NO the process shifts to step ST2. Step ST2 judges when the amount of print data stored in the buffer memory 5 has reached the threshold of 75% of the entire storage capacity of the buffer memory 5. At this time if, as shown by a shaded portion of Fig 2(I), the capacity of the printing data stored in the buffer memory 5 is less than 75% of the set value, for example 20, 45 or 70% of the entire storage capacity of the buffer memory 5, then NO is judged and the operation of the interface 3 is returned again to the step ST1. On the other hand, if as shown in a shaded portion of Fig. 2(II), the capacity of the printing data stored in the buffer memory 5 reaches 75% of the set value, YES is judged and the process shifts to next step ST3. In the step ST3, the printing of the printing data is instructed. More specifically each group of printing data stored in the buffer memory 5 is fed through the driver 6 to the printing mechanism 7, in. turn. The printing mechanism 7 then acts to print in response to the printing data received by the printing mechanism 7. Simultaneously, the amount the printing data stored in the buffer memory 5 is calculated as a number and this number reduced by "1". The process then shifts to step ST4, where the question "does the number of printing data become"0"?11 is judged.When the amount of printing data is 1 or more at this time, NO is judged, and the process is again returned to step ST3. The printing of new group of printing data is performed as before. The steps ST3 and ST4 are cycled until the amount of the printing data stored in the buffer memory reaches "O". In other words, as shown in Fig. 2(II), when the capacity of the printing data stored in the buffer memory 5 reaches the threshold value, the whole of the printing data stored is fed from the buffer memory 5 and printed by the printing mechanism 7 as shown in Fig. 2(III). When the entire amount of printing data stored in the buffer memory 5 has been printed, the number of printing data becomes !?0?1.

Accordingly, YES is judged in the step ST4 and the process is again returned to the step ST1 for the next batch printing.

On the other hand, when the switch for generating the independent print command is closed then in step ST1, YES is judged and the process is shifted directly to the step ST3 without the intermediary of the step ST2. The entire printing data stored in the buffer memory 5 so far is then printed.

If new interrupt printing data is fed from the host computer when the steps ST3 and ST4 are repeated at printing time, the print controller 2 receives the printing data as shown in Fig. 4, feeds the printing data to the buffer memory 5 to store them in the memory 5, adds "1" to the number of printing data stored in the buffer memory 5, and prints together with the printing data interrupted newly.

In the embodiment described above, in the normal printing operation time of the state that the switch for generating the independent print command is OFF in step ST1, the printing data is stored in the buffer memory 5 until the capacity of the printing data fed fom the host computer arrives at the set vallue, and when arriving at the set value, the entire stored printing data is printed by the printing mechanism 7. Therefore, the printing mechanism 7 does not oprate each time the printing data is fed from the host computer and so simplifies the printing operation for the printing data of the same capacity, to shorten the printing time, to reduce the power consumption necessary for printing, and to monitor the printing state by once which is executed plural times in the conventional printer to save the energy.

In the embodiment described above, the entire printing data stored in the buffer memory 5 can be immediately printed by the printer mechanism 7 irrespective of whether the buffer memory 5 arrives at the set value by turning ON the switch for generating the independent print command. Therefore, a trial printing or emergency printing or reprinting can be arbitrarily performed.

The set value for determining the time when the printing is started by the printing mechanism 7 may be determined to be any suitable value by considering the entire storage capacity of the buffer memory 5, using the object and utility of the printer 1.

Since the printer of this invention is constructed as described above, the printing data fed to the printer is temporarily stored, and when the stored printing data arrives at a predetermined value, the stored printing data are simultaneously printed to improve the printing efficiency, to save energy and power.

Claims

1. A printer having a printing mechanism for printing in response to printing data comprising a buffer memory for temporarily storing printing data to be fed, and a print controller for feeding the stored printing data to the printing mechanism to print when the ratio of the capacity of the stored printing data to the total storage capacity of the buffer memory reaches at a set value or when an independent printing command is generated.

2. A printer according to Claim 1, used in combination with a host computer wherein said print controller includes a ROM and the buffer memory for temporarily storing printing data from the host computer.

3. A printer substantially as hereinbefore described with reference to the accompanying drawings.