JPH05270080A - Printer - Google Patents

Abstract

PURPOSE:To eliminate discharge of a blank sheet when a sheet is discharged. CONSTITUTION:When printing data is received, whether the received data is effective data to be actually printed or not is judged (step S4). If the data is effective, an effective data flag is turned on (step S5), but if it is blank data, etc., the flag is not turned on. When a sheet discharge command is received or the quantity of the data reach the amount for one page, whether the flag is ON or not is judged (step S7). In this case, if the flag is ON, the data is printed and the sheet is discharged (step S8), but if the flag is OFF, the effective data is not received, and hence the sheet is not discharged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing device such as a page printer which is connected to a personal computer or the like and prints out page by page using cut sheets.

[0002]

2. Description of the Related Art A conventional page printer prints and discharges a sheet when the sheet is discharged, that is, when one page of print data is full or a sheet discharge command or a page break command is received from a personal computer. ing.

[0003]

However, in the conventional page printer, when the print data of one page stored in the print buffer is blank data, or when the paper discharge instruction is received when the print buffer has no data, the print data is actually output. Has a drawback in that blank paper is discharged without printing on paper. An object of the present invention is to prevent a blank sheet from being discharged when discharging a sheet.

[0004]

Means for Solving the Problems The means of the first invention is as follows. The valid data determining means determines whether the received print data is valid data. The valid data receiving / storing means stores that valid data has been received based on the judgment of the valid data judging means. The paper discharge control means judges the contents of the valid data receiving and storing means when discharging the paper, and does not discharge the paper when the valid data is not received. The means of the second invention is as follows. The print data storage means stores the received print data. The valid data detection means detects whether or not valid data is stored in the print data storage means. The paper discharge control means prevents the paper from being discharged when the valid data is not detected by the valid data detecting means when the paper is discharged.

[0005]

The operation of the means of the first invention is as follows. For example, when print data sent from an external device such as a personal computer is received, the valid data determination means determines whether the print data is valid data, and when valid data is received, the status is checked. The valid data is stored in the storage means. Then, when the paper is ejected, the paper ejection control means judges the contents of the valid data receiving and storing means, and if the valid data is not received, the paper is not ejected. The operation of the means of the second invention is as follows. For example, the print data sent from an external device such as a personal computer and received is stored in the print data storage means, and the valid data detection means detects whether or not the valid data is stored in the print data storage means. Then, when the paper is ejected, the paper ejection control unit does not eject the paper when the valid data is not detected by the valid data detecting unit. Therefore, it is possible to prevent the blank sheet from being discharged when the sheet is discharged.

[0006]

[First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS. The first embodiment and a second embodiment described later show examples applied to page printers such as laser shot printers, LED page printers, and LCS page printers connected to personal computers.

FIG. 1 is a block diagram showing the circuit arrangement of a printing apparatus according to the first embodiment. The centro interface 1 receives print data sent from an external device such as a personal computer, responds to the personal computer with a reception completion signal, and inputs the received print data to the control unit 2. The control unit 2 controls each unit based on a control program, and is connected to the print buffer 3, the frame buffer 4, and the valid data flag 6.

The print data received by the centro interface 1 is stored in the print buffer 3 via the control unit 2. The print buffer 3 stores print data in a ring buffer format and has a capacity capable of storing print data over a plurality of pages. The frame buffer 4 is a memory that expands the print data for one page read from the print buffer 3 into a bit pattern format and stores it. Then, the expanded print data stored in the frame buffer 4 is sent to the printer 5 and printed.

The printer 5 prints out the developed print data read from the frame buffer 4 page by page on cut paper (for example, A4 size paper, B4 size paper, etc.) set in a paper cassette (not shown).

The valid data flag 6 is turned on, for example, "1" is written when the received print data is valid data. That is, when the valid data flag 6 is ON, it indicates that valid data has been received. Here, the valid data is print data that is actually printed on the paper. Therefore, print data such as blank data and line feed data that is not printed on the paper is not included in the valid data.

Next, the operation of the first embodiment will be described.
FIG. 2 is a flow chart showing the operation of the printing process. The print processing is executed in page units. First, in step S1, the valid data flag 6 is turned off and initialization is performed. For example, "0" is written.

In subsequent step S2, the print data sent from an external device such as a personal computer is received by the centro interface 1, and the centro interface 1 inputs the received print data to the control unit 2. Then, the received print data is sequentially stored in the print buffer 3 under the control of the control unit 2 and is expanded into a bit pattern and stored in the frame buffer 4. In the next step S3, the control unit 2 determines whether the received print data is a paper discharge command (or a page break command). If Yes is determined in step S3, the process proceeds to step S7, and if No, the process proceeds to step S4.

If the received print data is other than the paper discharge command, No is determined in step S3 and the process proceeds to step S4.
In step S4, it is determined whether the received print data is valid data, that is, print data for actually printing on a sheet. In step S4, if the received print data is not valid data and is non-print data such as blank data or line feed data, it is determined as No, and the process proceeds to step S6. If it is valid data, it is determined as Yes. And proceed to step S5.

If valid data is received, step S4
To step S5. In step S5, the valid data flag 6 is turned on. That is, "1" is written in this first embodiment. After execution of step S5, step S
Proceed to 6. If the received print data is not valid data, for example, if the print data is blank data, it is determined No in step S4 and the process proceeds to step S6.

In step S6, it is determined whether or not the data is Full, that is, whether or not the print data stored in the print buffer 3 reaches one page. If the print data is less than one page, it is determined No in step S6 and the process returns to step S2 to continue receiving the print data. Further, when the print data stored in the print buffer 3 reaches one page, it is determined as Yes in step S6 and the process proceeds to step S7.

If a paper discharge command is received, or if the data becomes Full, step S7 is executed.
In step S7, the valid data flag 6 is ON.
("1"), that is, whether valid data is received and stored in the print buffer 3 is determined. When the valid data flag 6 is OFF, since the print data to be actually printed is not stored in the print buffer 3, the paper is not discharged and the process returns to step S1. When the valid data flag 6 is ON, the print data to be actually printed is stored in the print buffer 3, and since this print data is expanded in the frame buffer 4, the process proceeds to step S8.

In step S8, the print data of the bit pattern expanded in the frame buffer 4 is sent to the printer 5 for printing, and the printed paper is discharged.

[0018]

[Second Embodiment] Next, a second embodiment of the present invention will be described. The circuit configuration of the printing apparatus according to the second embodiment is similar to that of the block diagram shown in FIG. 1 except that the valid data flag 6 is omitted, and therefore, illustration and description of the block diagram are omitted. The operation of the second embodiment will be described below with reference to FIG. FIG. 3 is a flow chart showing the operation of the printing process in the second embodiment.

First, in step S11, the above step S
Similar to 2, the print data sent from an external device such as a personal computer is received by the centro interface 1, and the centro interface 1 inputs the received print data to the control unit 2. Then, the received print data is sequentially stored in the print buffer 3 under the control of the control unit 2 and is expanded into a bit pattern and stored in the frame buffer 4.

In step S12, as in step S3, the control unit 2 determines whether the received print data is a paper discharge command (or page change command). If Yes is determined in step S12, the process proceeds to step S14, and if No, the process proceeds to step S13.
If the received print data is other than the paper ejection command, step S
If No, the result is 12, and the process proceeds to step S13.

In step S13, similarly to step S6, it is determined whether the data is Full, that is, whether the print data stored in the print buffer 3 has reached one page. If the print data is less than one page, No is determined in step S13 and the process returns to step S11.
Continue receiving print data. Further, when the print data stored in the print buffer 3 reaches one page, it is determined as Yes in step S13 and the process proceeds to step S14.

When the paper discharge command is received or the data becomes Full, step S14 is executed.
In step S14, it is checked whether or not valid data to be actually printed is stored in the print buffer 3. In the following step S15, it is determined whether there is valid data in the print buffer 3 based on the check in step S14. If it is determined No in step S15, the print data to be actually printed is not stored in the print buffer 3, so that the paper is not discharged and the process returns to step S11.

If it is determined in step S15 that there is valid data, the print data to be actually printed is stored in the print buffer 3, and this print data is expanded in the frame buffer 4. Therefore, the process proceeds to step S16. move on.
In step S16, similarly to step S8, the print data of the bit pattern expanded in the frame buffer 4 is sent to the printer 5 for printing, and the printed paper is discharged.

[0024]

According to the present invention, in a page printer or the like, it is possible to prevent a blank sheet from being discharged when the sheet is discharged.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration.

FIG. 2 is a flowchart showing an operation in the first embodiment.

FIG. 3 is a flowchart showing an operation in the second embodiment.

[Explanation of symbols]

 1 Centro interface 2 Control unit 3 Print buffer 4 Frame buffer 5 Printer 6 Valid data flag

Claims (2)

[Claims] 1. A valid data judging means for judging whether or not the received print data is valid data, and a valid data receiving memory for storing that the valid data is received based on the judgment of the valid data judging means. And the contents of the valid data receiving and storing means when ejecting the paper,
A printing apparatus comprising: a sheet discharge control unit that prevents a sheet from being discharged when valid data has not been received. 2. A print data storage means for storing the received print data, a valid data detection means for detecting whether or not valid data is stored in the print data storage means, and a paper discharge operation for discharging the paper. A printing apparatus comprising: a paper discharge control means for preventing the paper from being discharged when the valid data is not detected by the valid data detecting means.