JP2908571B2 - Page printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a page printer, and more particularly, to a double-sided printing even in a band buffer type page printer having a bit map memory having a storage capacity of less than one page. Paix is to be able to
Printer .

In general, in a page printer which performs printing by an electrophotographic system, print data is developed on a bit map memory, and the bit map memory is raster-scanned to read the print data. The printing is performed by an electrophotographic method.

In this case, the bit map memory usually has 2
It has a capacity to store print data for one page, and prints data for the next page while printing for one page is being performed.
When the printing of one page is almost completed, the conveyance of the paper for printing the next page is started to maintain the rated printing speed.

However, since the capacity of the bit map memory for storing print data for one page is large,
Gigaprinters become expensive. Accordingly, an inexpensive band buffer type page printer using a bit map memory capable of storing less than one page of data has recently been developed.

[0005] Although the page printer of the band buffer system is inexpensive, it can only perform one-sided printing due to the paper feed of the engine and the like. If the paper feed mechanism of the engine is improved, double-sided printing is possible, but it becomes an expensive device. Therefore, it is desired to enable double-sided printing even with an inexpensive page printer of the band buffer system.

[0006]

2. Description of the Related Art FIG. 4 is a block diagram of a conventional page printer, and FIG. 5 is an explanatory view of a conventional printing process. In the figure, 1 is a data input unit, 2 is a data processing unit, 3 is a print data control unit, 4 is a character generation unit, 5 is a bitmap memory, 6 is a video output unit, and 7 is printing start. Control unit, 8 is a scaler write control unit, 9 is a scaler, 10 is a scaler read control unit,
Reference numeral 11 denotes a printing mechanism, and 12 denotes a sheet.

As shown in FIG. 4, a conventional page printer based on the band buffer system has a data input unit 1, a data processing unit 2, a print data control unit 3, a character generation unit 4, a bit map, and the like. It comprises a memory 5, a video output unit 6, a print start control unit 7, a scaler write control unit 8, a scaler 9, a scaler read control unit 10, a print mechanism unit 11, and the like. Hereinafter, the printing process by the page printer will be described with reference to FIG.

[0008] Print data is input from a host computer via a terminal A to a data input unit 1 and sent to a data processing unit 2. The data processing unit 2 analyzes commands included in the print data and performs preprocessing for printing.

The data processor 2 first sends a print start signal to the print start controller 7 to start printing. The print activation control unit 7 activates a paper transport control unit (not shown) of the print mechanism 11 to transport the paper to the position of the photosensitive drum.

Next, a data processing unit 2 is a print data control unit 3
To send print data. When the print data control unit 3 extracts the print code from the print data, it reads out the character pattern from the character generation unit 4 and sends it to the scaler write control unit 16.

The scaler writing controller 8 calculates the position of the character pattern to be printed on the paper in units of the number of scans, and notifies the scaler 9 of the calculated number of scans.

For example, assume that character patterns A, B, C, D, and E are printed on the paper 12 as shown in FIG. 5, and the print data control unit 3 sends B, A, E, C, Assuming that the character patterns are input to the scaler writing controller 8 in the order of D, the scaler writing controller 8
The position where the image B is printed on the paper 12 is calculated by the number of scans,
Notify the scaler 9.

The scaler 9 registers the number of scans of the character pattern from the address corresponding to the number of scans from the upper end of the paper 12 to the upper end of the character pattern B. That is, assuming that the character pattern is composed of, for example, 24 dots, 24 scans have been registered as indicated by the diagonally left lines.

Since the character pattern is the character pattern registered first in the scaler 17, the address is sent to the bitmap memory 5 by filling the blank portion of the paper.
That is, if the address of the bitmap memory 5 starts from "000", "001-024" is transmitted. Therefore, the character pattern B is written in the bit map memory 5 as shown.

Next, the scaler writing control unit 8 transmits a character pattern.
The position where the image A is printed on the paper 12 is calculated by the number of scans,
Notify the scaler 9. The scaler 9 registers the number of scans of the character pattern from the address corresponding to the number of scans from the upper end of the sheet 12 to the upper end of the character pattern A.

That is, as shown by the right oblique line, 24 scans are registered. Since the character pattern is registered at the new address for the scaler 9, the next address is sent to the bitmap memory 5 so that the character pattern B is continuously written. That is, "025" is used as the address.
.048 ". Therefore, the bit map memory 5
As shown in the figure, a character pattern B is followed by a character pattern B.
A is written.

Next, the scaler writing control unit 8 transmits a character pattern.
The position where the image E is printed on the paper 12 is calculated by the number of scans,
Notify the scaler 9. In the scaler 9, the part overlapping the character pattern A is registered in the area where the character pattern A is registered, and the part overlapping the character pattern B is registered in the area where the character pattern B is registered. The registration is repeated, and only the unregistered address portion between the addresses of the scaler 9 is newly registered.

The scaler 9 sends the next address so that only the character pattern registered at the new character address is written in the bit map memory 5 continuously to the character pattern A. That is, for example, if the line interval is composed of 12 dots, "049 to 060" is transmitted as the address.

Therefore, as shown in the drawing, the portion where the character pattern B of the character pattern E and the scanning line overlap each other is written in the character pattern B area in the bit map memory 5, as shown in FIG. The portion where the scanning line overlaps the pattern A is the character pattern A
, And the portion corresponding to the remaining line spacing is written following the character pattern A.

Next, the scaler writing control unit 8 sends a character pattern.
The position where the image C is printed on the paper 12 is calculated by the number of scans,
Notify the scaler 9. The scaler 9 registers the number of scans of the character pattern from the address corresponding to the number of scans from the upper end of the paper 12 to the upper end of the character pattern C.

Since the character pattern is registered at the new address for the scaler 9, the next address is sent to the bit map memory 5 so that the character pattern E is continuously written. . That is, "061" is used as the address.
.084 ". Therefore, the bitmap memory 5
As shown in the figure, a character pattern C is written after a character pattern A, followed by a character pattern E corresponding to the line interval.

Next, the scaler writing control unit 8 executes the character pattern
The position where the image D is printed on the paper 12 is calculated by the number of scans,
Notify the scaler 9. The scaler 9 registers the number of scans of the character pattern from the address corresponding to the number of scans from the upper end of the paper 12 to the upper end of the character pattern D.

Since the character pattern is registered at the new address for the scaler 9, the next address is sent to the bit map memory 5 so that the character pattern C is continuously written. . That is, the address “085
１０８108 ″.

Therefore, a character pattern D is written in the bit map memory 5 following the character pattern C as shown in FIG.

When the line of the character pattern registered in the scaler 9 exceeds the boundary of the printing area of the sheet, the video output unit 6 is instructed to send a video signal through the print start control unit 7. You.

The scaler read control unit 10 includes a scaler 9
The address is read out from the upper end in synchronization with the raster scanning of the video output unit 6 and sent to the video output unit 6. The video output unit 6 outputs the bit map memory 5 according to the address.
The raster scanning is sequentially started from the upper end of the frame, and a video signal for each scanning is sent to the printing mechanism unit 11.

The space between the addresses of the scaler 9 corresponds to the margin of the sheet, and the address of the bit map memory 5 sent to the video output unit 6 by the scaler read control unit 10 is continuously "000". The video signal transmitted from the video output unit 6 to the printing mechanism unit 11 is blank data having no character pattern. Therefore, the printing of the character pattern is not performed by the printing mechanism unit 15, and the paper is fed by the amount corresponding to the margin of the paper.

The scaler read control unit 10 controls the scaler 9
Is read out, the address of the bit map memory 5 sent to the video output unit 6 is "025", and as the address of the scaler 17 is read out,
The addresses of the bitmap memory 5 are sequentially transmitted from "025" to "048". This is a bitmap memory 5 for printing a part of the character pattern A and a part of the character pattern E.
The printing is performed by the printing mechanism unit 11.

The scaler read control unit 10 controls the scaler 9
Is read out, the address of the bit map memory 5 sent to the video output unit 6 is "049". As the address of the scaler 9 is read out, the address of the bit map memory 5 becomes "049". From "060". This is an address of the bit map memory 5 for printing a part of the character pattern E, and printing is performed by the printing mechanism unit 15.

The scaler read control unit 10 controls the scaler 9
Is read out, the address of the bit map memory 5 sent to the video output unit 6 is "061". As the address of the scaler 9 is read, the address of the bit map memory 5 becomes "061". From "084". This is a bit map memory 5 for printing a part of the character pattern E and the character pattern B.
The printing is performed by the printing mechanism unit 11.

The scaler read control unit 10 controls the scaler 9
Is the area that indicates the line spacing when the address of
The address of the bit map memory 5 sent to the video output unit 6 is "000". Until the address of the scaler 17 is read, "000" is transmitted as the address of the bit map memory 5.

Accordingly, the printing of the character pattern is not performed in the printing mechanism section 11, and the paper is fed by an amount corresponding to the line interval of the paper. The same applies to the case where a character pattern D is read after a character pattern C.

[0033]

The above-mentioned conventional apparatus has the following disadvantages.

(1) In the page printer of the band buffer system, the printing direction is always in the same direction, and furthermore, due to the structure of the printing mechanism, it was not possible to perform double-sided printing.

That is, in a printer such as the conventional example described above, if double-sided printing is performed without changing the data control, the direction of characters and the like on the front and back sides is reversed, and double-sided printing is impossible. is there.

(2) If the paper feeding mechanism is improved so that the paper can be turned inside out, double-sided printing is possible even in a page printer of the band buffer system.

However, in this case, the printer is expensive and large.

The present invention solves such a conventional drawback, and can be applied to a band buffer type page printer.
An object of the present invention is to enable double-sided printing and to provide an inexpensive and small printer.

[0039]

FIG. 1 is a diagram showing the principle of the present invention, in which the same reference numerals as in FIG. 4 denote the same parts. Also,
Reference numeral 12 denotes a deployment direction control switching unit.

The present invention has the following configuration to achieve the above object. That is, data storage capacity of less than one page
A bit map memory 5 which has an amount and which develops print data in bits, and registers and manages a character pattern write address to the bit map memory 5 for each scan.
A scaler 9 for sending a character pattern to the bitmap memory 5 for each scan , and calculating a position of the character pattern to be printed on the paper when writing the character pattern in the bitmap memory 5
And a scalar write control unit 8 to be registered in the scalar 9;
And a reading scaler read control unit 10 an address for reading a character pattern from a bit map memory 5 from the scaler 9 for each scan, child printing on both sides of the paper
To a band buffer type page printer that enables
The scaler 9 is switched so that the developing direction of the scaler 9 is reversed at the upper end and the lower end at the time of printing on the front side and the time of printing on the back side of the paper.
And a deployment direction control switching unit 12 for performing the control.

[0041]

Since the present invention is constructed as described above, it has the following effects.

In FIG. 1, a scaler write control unit 8
Registers the position to be printed on the character pattern paper on the scaler 9 at the address corresponding to the paper. Scaler 9 is
To the bit map memory 5, an address for storing a character pattern is sent out with necessary margins and line intervals on a sheet. Thus, the character pattern is stored in the bit map memory 5.

Then, in the scaler read control unit 10,
The video output unit 6 is instructed to read the character pattern from the address of the bit map memory 5 indicated by the scaler 9. As a result, it is possible to transmit a video signal to the video output unit 6 in which the margin on the paper and the line spacing have been restored. The video output unit 6 passes the data to the printing mechanism unit and performs printing.

As described above, even a page printer having the bit map memory 5 having a data storage capacity of less than one page can perform printing without lowering the printing speed. During this printing, the developing direction control switching unit 1
In step 2, the printing surface information (information on the front or back of the sheet) from the data processing unit 2 is input, and the scaler writing control unit 8 and the scaler reading control unit 10 are controlled.

With this control, the developing direction of the scaler 9 is controlled to be reversed between the front side printing and the back side printing of the paper, and printing on both front and back sides is performed. In this way, even an inexpensive page printer of the band buffer system can print on both the front and back sides of a sheet without reducing the printing speed.

[0046]

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

FIG. 2 is a block diagram of a page printer (band buffer system) according to an embodiment of the present invention.
FIG. 5 is an explanatory diagram of double-sided printing control in the embodiment.
In the drawing, the same reference numerals as those in FIGS. 1 and 4 denote the same components.

This embodiment is an example in which the present invention is applied to a page printer having the same configuration as that of the above-described conventional example. The page printer is provided with a developing direction control switching unit 12. Therefore, the configuration other than the development direction control switching unit 12 and the operation thereof are the same as those of the above-described conventional example.

This page printer is a page printer of a band buffer system, and the storage capacity of the bit map memory 5 is less than one page. Such a page printer is configured as shown in FIG. 2 in order to print the characters on both the front and back sides of a sheet without lowering the printing speed and to print the characters.

That is, the page printer of this embodiment has a data input unit 1, a data processing unit 2, a print data control unit 3,
A character generator 4, a bitmap memory 5, a video output unit 6, a print start controller 7, a scaler write controller 8, a scaler 9, a scaler read controller 10, a print mechanism 11,
A deployment direction control switching unit 12 is provided.

The data input section 1 performs data input processing from the host computer, and performs processing such as converting serial data sent from the host into parallel data. I do.

The data processing section 2 receives the data sent from the data input section 1 and performs various data processing. The processing includes sending a print start signal to the print start control unit 7 to start printing, and setting the developing direction control switching unit 12 to output sheet information such as whether to print the front side or the back side of the sheet. Is transmitted.

The data processing section 2 controls the print data control section 3 to send print data. When the print data control unit 3 extracts the print code from the print data,
The character pattern is read from the character generator 4 and sent to the scaler write controller 8.

The scaler 9 stores 1 in the bitmap memory 5.
The address is managed for each scan, and is managed in units of scanning from the upper end to the lower end of the sheet or from the lower end to the upper end of the sheet. Also, this scaler 9 is used for two pages of paper.
It has a memory capacity to manage more than
Since only addresses for each scan are managed, a small-capacity memory is sufficient. Further, the output address is sent from the scaler 9 to the bit map memory 5.

The scaler writing control unit 8 includes a scaler 9
In addition, the position of the character pattern to be printed on the paper is registered in the address corresponding to the paper, and the necessary margin and line interval are filled in the bitmap memory 5 on the paper to form the character pattern. The address to be stored is transmitted, and control is performed to store the character pattern in the bit map memory 5.

The scaler read control unit 18 includes the scaler 9
The video output unit 6 is instructed to read a character pattern from the address of the bit map memory 5 indicated by the instruction, and sends the video output unit 6 a video signal in which the margin on the paper and the line interval are restored. Is what you do.

The developing direction control switching unit 12 receives print surface information (information on whether front side printing or back side printing) from the data processing unit 2, and outputs a scaler write control unit 8 and a scaler read control unit. It sends a control signal of the developing direction to 10 to give an instruction.

Next, a double-sided printing process based on the above configuration is described.
This will be described with reference to FIG. FIG. 3A is an explanatory diagram at the time of front side printing, and FIG. 3B is an explanatory diagram at the time of back side printing.

In the sheet feeding, first, the front side is printed while feeding the sheet in the first direction, and after the front side printing is completed, the back side printing is performed while the sheet is fed in the second direction opposite to the first direction. Things. That is, at the time of back side printing, sheet feeding is performed so that the sheet feeding path at the time of front side printing is reversed.

When printing is performed on the front side of the sheet, the developing direction control switching unit 12 sends the scaler writing control unit 8
An instruction is issued to the color reading control unit 10 to switch the scaler developing direction to the developing direction for front side printing. The developing direction is as shown in FIG. 3A, which is the same as the above-mentioned conventional example.

For example, print data (bitmap data)
As shown in the figure, if uppercase letters "A" and "B" and lowercase letters "a" and "b" are
"B" and lowercase letters "a" and "b" perform video development separately from the upper end (upper end management). That is, video development is performed from the upper end to the lower end of each character.

At this time, the management of the scaler 9 is controlled by each page.
The video is developed from the upper end to the lower end of the page (upper end management). By performing such upper end management, front side printing can be performed.

Next, when printing the back side of the sheet, the developing direction control switching unit 12 sends the scaling direction of the scaler to the scaler writing control unit 8 and the scaler reading control unit 10. , And instruct to reverse. The scale in this case
The deployment direction of the la 9 is as shown in FIG. 3B.

In this case, the print data (bitmap data)
As shown in the figure, if the uppercase letters "A" and "B" and the lowercase letters "a" and "b" as shown in FIG. Yes (lower end management). The management of the scaler 9 is controlled by each page.
The video is developed from the lower end to the upper end of the page (lower end management).

As described above, if the developing direction of the scaler is reversed at the time of printing on the front side and the back side of the paper, the printing can be performed in the same character direction on the front side and the back side. Note that the other controls and processes are the same as those in the above-described conventional example, and thus the description thereof is omitted.

[0066]

As described above, the present invention has the following effects.

(1) Double-sided printing is also possible in a band buffer type page printer using a bit map memory capable of storing only less than one page of data.

(2) It is possible to obtain a small-sized band buffer type page printer capable of duplex printing without lowering the printing speed and at a low price. That is, since a developing direction control switching unit may be added to the control unit of the printer, a smaller and less expensive page printer can be obtained than in the case where the printing mechanism is improved.

[Brief description of the drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a block diagram of a page printer according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of double-sided printing control in the embodiment.

FIG. 4 is a block diagram of a conventional page printer.

FIG. 5 is an explanatory diagram of a conventional printing process.

[Explanation of symbols]

 Reference Signs List 1 data input unit 2 data processing unit 3 print data control unit 4 character generation unit 5 bitmap memory 6 video output unit 7 print start control unit 8 scaler write control unit 9 scaler 10 scale Reading control unit 11 printing mechanism unit 12 developing direction control switching unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁶ , DB name) B41J 3/60 B41J 5/30 H04N 1/21

Claims (1)

(57) [Claims] Claims: 1. A printer having a data storage capacity of less than one page.
A bit map memory for bit developing character data, a character pattern writing address to said bit map memory
The address is registered and managed for each scan, and the address is scanned for one scan.
A scaler to be sent to the bit map memory for each, the time of writing a character pattern in the bit map memory, scaler write control register to calculate the position to be printed on the paper of the character pattern wherein the scan <br/> scaler comprising a part, and a reading scaler read control unit an address for reading a character pattern from a bit map memory for each scan from the scaler, it made it possible to print on both sides of the paper Bandoba'
In page printer file system, and when the surface printing paper, at the time of backside printing, the upper end of the deployment direction of the scaler, the switching control so the lower end is opposite
A developing direction control switching unit for performing
Printer.