JPH05224845A - Printer sharing system - Google Patents

Abstract

PURPOSE:To provide the printer sharing system for releasing an occupied state immediately after printing-out is completed. CONSTITUTION:This system is provided with one printer 6, plural controllers 1, 2 and 3 sharing the printer 6, selection part 4 to occupy the printer 6 while selectively connecting any one of plural controllers 1, 2 and 3 first outputting data, and a release control part 5 to release the selectively connected state of the controller selectively connected by the selection part 4 when it is detected that the data are data instructing the discharge of paper showing the end of printing-out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer sharing system for sharing a printer of a control device such as a personal computer installed in an office environment.

[0002]

2. Description of the Related Art Conventionally, in the case of sharing a printer with a control device such as a personal computer, the control device that first outputs data to the printer puts the printer in the occupied state, and thereafter only the occupied control device sends to the printer. Is enabled, and the release of the occupied state is performed when the control device in the occupied state does not use the printer for a certain period of time. Further, in another example of releasing the occupied state, the control device in the occupied state explicitly releases the release instruction to release the occupied state.

[0003]

The interface for sharing the printer described above has the following problems in order to release the occupied state of the printer.
When releasing the occupied state after the printer is not operating for a certain period of time, if the allowable downtime is set to a long value, even if the control device occupying the printer finishes using the printer, another control device will not The unusable time becomes long and the operating rate of the printer as a system becomes low.

If the set value of the permissible down time is shortened, the occupied control device takes a long time to process, and if the permissible down time is exceeded, the control device becomes occupied with another control device during printing. Problem that print result is disturbed,
It was difficult to properly determine the allowable downtime.

Further, when the control device explicitly releases the occupied state by a command or the like, it is necessary to control the printer in consideration of the occupied state, and it is necessary to modify the control device to control the occupied state. become. Therefore, it is impossible to share a printer without modifying a standard printer-occupying type control device such as a personal computer which is widely used.

It is an object of the present invention to utilize a standard printer occupation type control device such as a personal computer to share a printer with an interface in which the occupation state is immediately released by discharging the paper when the print output is completed. To provide a method.

[0007]

According to the printer sharing method of the present invention, one printer, a plurality of control devices that share the printer, and a plurality of control devices that first output data are selected. A selection unit that connects and occupies the printer, and a selection connection state of the control device that is selectively connected by the selection unit when it is detected that the data is data indicating the end of print output and instructing paper discharge And a release control unit for releasing.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

Referring to FIG. 1, which shows the configuration of an embodiment of the present invention, here is shown a case where three control devices share one printer for use.

Each of the control devices 1, 2 and 3 creates print data for the printer 6 each time a print request is generated, and the interfaces 11, 12, 1 are mutually independent of other control devices.
3 is a device such as a personal computer that outputs the print data created through the step 3, and the control device that first outputs the data occupies the printer and prints the data. The selection unit 4 is connected to the control devices 1, 2, and 3 via the interfaces 11, 12, and 13, and transfers print data from only one control device to the release control unit 5 through the interface 14 at a certain point of time.

The release controller 5 connects the interface 14 and the interface 15, decodes the print data transferred into the interface, and terminates the print output by detecting the control code recognized by the printer 6 for instructing the paper discharge. It recognizes and issues an occupation release instruction from the printer occupation state of the control device to the selection unit 4.

The printer 6 is a low-speed printer connected to a control device such as a personal computer, and transfers print data by an interface commonly called as Centronics compliant, and prints on paper. Interfaces 11 to 1
5 is composed of all the interfaces that are said to be Centronics compliant. Therefore, the control devices 1, 2,
3 is recognized as being directly connected to the printer 6 via the interfaces 11, 12, and 13, and the release control unit 5 is recognized by the printer 6 as a higher-level control device.

In the printer sharing system described above,
When a print request is generated, the control device 1 creates print data for the printer 6 and tries to output the data through the interface 11. At this time, if the selection unit 4 is in the initial state and print data is not input from any other control device, the selection unit 4 prevents the control devices 2 and 3 from receiving print data.
2 and 13 are controlled in a busy state so that only the control device 1 can occupy and use the printer 6. Then, the output data of the control device 1 is transferred to the interface 14.
That is, the selection unit 4 has the control device 1,
Of the two and three, only the data of the control device which receives the print data first is output to the interface 14, and the print data is apparently busy so that the print data cannot be output to the other control devices 2 and 3. Put in a state. This state is called the occupied state of the control device 1. When the printing is completed, the control device 1 finally outputs the data instructing the paper ejection. The release control unit 5 decodes the data, sends the occupation release instruction signal 20 to the selection unit 4, and releases the occupied state of the control device 1.
The selection unit 4 returns to the initial state, and all the control devices 1, 2, 3
It becomes possible to output new data to. The selection unit 4 in the occupied state becomes the initial state, and the interface 11,
Since 12 and 13 are not in the busy state, the control device which has been waiting for the character output can print out. The operation is the same as that described above in which the control device 1 outputs to the printer 6.

[0014]

As described above, according to the present invention, the printer can be shared without modifying the control device such as a personal computer that occupies and uses the printer, and the paper discharge data immediately after completion of the print output can be immediately used. It is possible to release the occupied state and improve the operating rate of the printer.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an exemplary embodiment of the present invention.

[Explanation of symbols]

 1 Control Device 2 Control Device 3 Control Device 4 Selection Unit 5 Release Control Unit 6 Printer 11 to 15 Centronics Compliant Interface 20 Occupation Release Instruction Signal

Claims (3)

[Claims] 1. A printer, a plurality of control devices that share the printer, and a selection unit that selectively connects any of the plurality of control devices that first output data to occupy the printer. And a release control unit for releasing the selective connection state of the control device selectively connected by the selection unit when it is detected that the data is data for instructing paper discharge indicating the end of print output. Printer sharing method. 2. The printer sharing system according to claim 1, wherein each of the plurality of control devices is a personal computer. 3. The interface between each of the plurality of control devices and the selection unit, between the selection unit and the release control unit, and between the release control unit and the printer is a Centronics compliant interface. Claim 1
Printer sharing method described.