JPH082016A - Printer - Google Patents

Abstract

PURPOSE:To enable sure execution of printing without using a bit map memory for one page, by a method wherein input data are analyzed, intermediate data having printing position information are prepared, parted on the basis of the printing position information, developed in a bit map and printed and printed paper is reversed and fed again. CONSTITUTION:Print data from a host computer 1 are received by an interface 2 and stored in a reception buffer. CPU 3 takes out the print data for one page, analyzes them and prepares intermediate data having an absolute printing position of each print data. Then, it is judged whether each printing position of the intermediate data is located in the upper or lower half of paper. Moreover, it is judged whether the position is located in the first page or not, and based on the results of these judgements, the intermediate data are parted and stored in memories 8a to 8d. These intermediate data are developed in a bit map memory 7 and printed at a prescribed position. Printed paper is sent to a reversing unit to be fed again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus, and more particularly, to a printing apparatus for reversing a sheet which has been printed once and re-feeding the sheet for printing.

[0002]

2. Description of the Related Art Conventionally, in a printing apparatus such as a laser beam printer which prints on a page-by-page basis, all the printing for at least one page is developed into a bitmap,
It was printed on paper. According to this method, a bitmap memory for one page must be prepared without fail, and a large amount of memory is required for high-resolution printing, which causes a cost increase. In particular, in order to perform double-sided printing at high speed, a huge amount of memory is required. In order to cope with this, band processing is known as a method of developing and printing with high resolution even with a small memory.
In band processing, a bitmap of a certain width is repeatedly used within one page, and the printed image is developed little by little from the top or bottom and printed on paper.

[0003]

However, in the band processing of the above-mentioned conventional example, the expansion for printing the next band is performed within the time for actually printing the bitmap expanded into one band width on the paper. However, in a laser beam printer or the like where the paper conveyance speed is constant, if complicated data that cannot be expanded within that time is input, an error will occur. Then, the user who cannot add the memory cannot print the data at all. The present invention has been made in view of the above-mentioned conventional example, and an object of the present invention is to provide an apparatus that reliably prints without preparing a bitmap memory for one page.

[0004]

In order to achieve the above object, the printing apparatus of the present invention has the following configuration. That is, means for analyzing the input data and creating intermediate data having print position information on the paper, means for distributing the intermediate data based on the print position information, and a plurality of means for storing the distributed intermediate data. It has a memory, a memory for developing a bitmap, a unit for reversing and re-feeding a sheet once printed, and a sheet feeding control unit for controlling the sheet re-feeding unit.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. Before describing the configuration of the present embodiment, the configuration of a laser beam printer having a double-sided printing function to which the present embodiment is applied will be described with reference to FIG. The printing apparatus in the embodiment will be described by taking a laser beam printer as an example. However, as will be apparent from the following description, as a printing method, a thermal transfer recording method, an inkjet recording method,
Since it can be applied to the wire dot impact method etc.,
The present invention is not limited by the printing method.

FIG. 1 is a cross-sectional view showing an internal structure of a laser beam printer (hereinafter, abbreviated as LBP) applied to this embodiment. This LBP is for registering a character pattern from a data source (not shown) and a fixed format ( You can register (form data) etc. In the figure, reference numeral 1000 denotes the LBP main body, which is an externally connected host computer 1 (see FIG. 2).
Input and store the character information (character code) and form information or macro commands supplied from
A corresponding character pattern, form pattern, or the like is created according to the information, and an image is formed on a recording paper, which is a recording medium.

Reference numeral 1012 is a switch for operation and L
An operation panel 1001 is provided with an ED display and the like, and a printer control unit 1001 controls the entire LBP 1000 and analyzes character information supplied from a host computer. The control unit 1001 mainly converts character information into a video signal of a corresponding character pattern and outputs the video signal to the laser driver 1002.

The laser driver 1002 is a semiconductor laser 1
This is a circuit for driving 003, and switches on and off the laser light 1004 emitted from the semiconductor laser 1003 according to the input video signal. Laser 1004
Is horizontally swung by the rotary polygon mirror 1005 and the electrostatic drum 1
Scan 006. As a result, an electrostatic latent image having a character pattern is formed on the electrostatic drum 1006.

The latent image is developed by a developing unit 1007 around the electrostatic drum 1006 and then transferred to a recording paper. A cut sheet is used as the recording sheet, and the cut sheet recording sheet is stored in a sheet cassette 1008 attached to the LBP 1000 and is taken into the apparatus by a sheet feeding roller 1009 and conveying rollers 1010 and 1011.
It is supplied to the electrostatic drum 1006. When re-feeding,
The reversing flapper 1013 allows the paper reversing unit 1
It is sent to 014, taken into the apparatus again, and supplied to the electrostatic drum.

FIG. 2 is a block diagram showing the schematic arrangement of the printing apparatus of this embodiment. In FIG. 2, 1 is an information processing device such as a host computer, 2 is an input interface for receiving print data and control commands from the host computer,
3 is a CPU for performing printer control including analysis of print data, creation of intermediate data, expansion into a bit map memory, and refeed processing, 4 is a ROM storing the control program of the CPU 3 and various data, 5 is a RAM for temporarily storing various data, 7 is a bit map memory for expanding the print result from the intermediate data, 8a, 8b, 8c, 8d are memories for storing the intermediate data, and 9 is a print processing result of each emulator. Print output interface for output, 1
Reference numeral 0 is a print mechanism that outputs the print processing result sent from the print output interface. Each of these components is connected to the system bus 6.

Next, the processing contents of the printing apparatus will be described with reference to the flowchart of FIG. First, the printing device receives print data sent from an information processing device such as a host computer (step S1). This data is read into the reception buffer (step S2), and the print data for one page (for example, the front side in the case of double-sided printing) is taken out of the data (step S3). The print data is analyzed to create intermediate data having an absolute print position where each print data is printed on the paper (step S4), and each intermediate data is printed on the upper half of the paper or below the paper. It is determined whether or not printing is performed in half (step S5).

Next, it is judged whether or not it is the first page (step S6), and if it is the processing of the first page (odd page), the upper half data is transferred to the memory (8a) and then to the memory (8a). Half the data is stored in the memory B (8b) (step S7), the process returns to step S3, and the print data for the next one page (that is, the second page) is taken out. If it is the processing of the second page (even page) (for example, the back side in the case of double-sided printing) in step S6, the upper half data is stored in the memory C (8c) and the lower half data is stored in the memory D. The data is stored in (8d) (step S8). When the two pages have been sorted, the intermediate data is taken out from the memory A, developed on the bit map memory 7, and printed on the upper half of the front side of the sheet (step S9). The sheet is sent to the reversing unit 1024 and transferred to the refeed port (step S
10).

Next, the intermediate data is retrieved from the memory D,
The image is inverted on the bitmap memory 7 and printed on the lower half of the back side of the sheet (step S11). Paper reversing unit 1
It is sent to 024 and transferred to the re-feeding port (step S12).
Next, the intermediate data is taken out from the memory B, developed on the bitmap memory 7, and printed on the lower half of the front side of the paper (step S13). The sheet is sent to the reversing unit 1024 and transferred to the refeed port (step S14). Next, the intermediate data is taken out from the memory C, developed on the bitmap memory 7, and printed on the upper half of the back side of the paper (step S
15) The paper is discharged.

As described above, in this embodiment, for example, paper feeding or paper refeeding is performed during the period when the storage of the bitmap memory is updated, so that it takes time for the half-page bitmap memory. Therefore, it is possible to print reliably without causing an error. Especially, in this embodiment, since the double-sided printing mechanism can be used as it is, only the control section is provided.
The present invention can be realized.

In the embodiment, the processing for the data for double-sided printing has been described, but single-sided printing may also be used. In addition, in step S11 and step S15, although it was inverted when the bitmap was developed, it was not inverted on the bitmap,
It may be reversed when printing on paper. Also step S
In steps 9 to S15, the printing procedure in the case where the upper end of the front side of the page and the upper end of the back side of the page are described, but the procedure may be such that the left end of the front side of the page and the right end of the back side of the page match.

Also, an example using a bit map memory for half the number of paper pages has been described, but at the expense of printing speed,
It may be possible to repeatedly re-feed and print with a smaller bitmap memory. The present invention may be applied to a system including a plurality of devices or an apparatus including a single device. It goes without saying that the present invention can also be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0017]

As described above, according to the present invention,
Without preparing the bitmap memory for one page,
An apparatus for surely printing can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is a block diagram of a printing apparatus.

FIG. 3 is a flowchart showing operation processing contents of the printing apparatus.

[Explanation of symbols]

 1 Host Computer 2 Input Interface 3 CPU 4 ROM 5 RAM 6 System Bus 7 Bitmap Memory 8a Intermediate Data Memory A 8b Intermediate Data Memory B 8c Intermediate Data Memory C 8d Intermediate Data Memory C 9 Printout Interface 10 Output mechanism

Claims (4)

[Claims] 1. An intermediate data creating unit that analyzes input data and creates intermediate data having print position information on a sheet, and sorts the intermediate data created by the intermediate data creating unit based on the print position information. Distribution means, a plurality of memories for storing the intermediate data distributed by the distribution means, a bitmap memory for developing a bitmap based on the intermediate data sequentially read from the plurality of memories, and the bitmap Printing means for printing based on the data developed in the memory; refeeding means for reversing and refeeding the paper once printed by the printing means; and paper feeding control means for controlling the refeeding means A printing apparatus comprising: 2. A first memory means for receiving and storing data from an information processing device, and print data for each page from the data stored in the first memory means, and intermediate data divided for each print position. Intermediate data creating means for creating, a plurality of second memory means for storing the intermediate data created by the intermediate data creating means for each data, and the plurality of second memory means
A bitmap memory for developing a bitmap based on the intermediate data sequentially read from the memory means, a printing means for performing printing based on the data corresponding to the intermediate data developed by the bitmap memory, and the printing means 2. A printing apparatus, comprising: a sheet re-feeding unit that reverses and re-feeds a sheet that has been once printed in step 1, and a sheet feeding control unit that controls the sheet re-feeding unit. 3. The printing device according to claim 2, wherein the printing device is a double-sided printing device, and further has a determination means for determining whether the page is an odd number or an even number after creating one page of intermediate data. However, when the determination unit determines that the page is one of the odd-numbered page and the even-numbered page, the intermediate data is stored in a part of the plurality of second memory units and then the first data is stored in the second memory unit. Printing wherein one page of print data of another page is taken out from the data stored in one memory means to create intermediate data and stored in another part of the plurality of second memory means apparatus. 4. The printing apparatus according to claim 3, wherein after storing the odd-numbered and even-numbered intermediate data in the second memory means, printing corresponding to one intermediate data of one page is performed, Next, printing is performed corresponding to the intermediate data of one of the other pages, then printing corresponding to the other intermediate data of the one page, and then,
A printing apparatus for performing printing corresponding to other intermediate data of other pages.