JPH02190371A - Page printer - Google Patents

Abstract

PURPOSE:To print data on a sheet of other size than mounted sheets even if it is not mounted in a sheet printer of developed size designated by a host system by providing means for editing the size of picture information to the size of a recording sheet to print on a mounted recording sheet. CONSTITUTION:When printing image is developed on a frame memory 21 with a sheet size designated first from a host system to complete one page in a controller 20 of a control package 15, the sheet sizes of sheet cassettes 8, 9 mounted in a printer body are then read from detection signals of sensors 81, 91. Then, whether the sheet size designated from the host system coincides with that of any sheet cassette or not is judged. On the other hand, if there is no mounted sheet designated from the host system, whether a forcible print command is generated or not is judged. When the forcible print command is generated, an enlargement or contraction rate is calculated with the developed size in the frame memory and the size of the mounted sheet, and indexed. Then, the image developed in the frame memory is enlarged or contracted in response to the obtained enlargement or contraction rate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a page printer capable of printing documents and the like at high speed.

[Prior art]

In a page printer, print data for one page is created in the expanded size of print data specified by an external host, and printing is started.

[Problem to be solved by the invention]

By the way, in such a printer, if the expanded size of the print data is different from the size of the paper loaded in the printer, printing will not start until paper of the specified expanded size is supplied. .

However, if the specified paper cassette has been removed for some reason, or if the specified paper itself is not available,
It's very inconvenient because it doesn't print.

The present invention has been made in view of such circumstances, and even if the paper of the expanded size specified by the host is not loaded in the printer, it is possible to print data on paper of other loaded sizes. The purpose is to provide a page printer with a high level of functionality.

[Means to solve the problem]

The page printer according to the present invention prints an image on recording paper based on image information input from the outside, and includes a paper size detection means for detecting the size of the loaded recording paper, and a paper size detection means for detecting the size of the loaded recording paper; a comparison means for comparing the image size of the loaded image with the size of the loaded recording paper; and means for editing the size of the image information to the size of the recording paper.

[Effect]

The size of the loaded recording paper is detected by the paper size detection means, and if the detected recording paper size and the externally specified image size are different, the image information size will be changed to the loaded recording paper size. Edited to print to paper size.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof. FIG. 1 is a schematic vertical sectional view showing the internal structure of a page printer according to the present invention.

A charging corotron 2 is provided above the photoreceptor drum 1, which is rotated in the direction of arrow a, and the charging corotron 2 charges the surface of the photoreceptor drum 1 to a predetermined potential. An LED head 3 is provided on the downstream side of the charging corotron 2 in the direction of rotation of the photoreceptor drum, and a control package 15 described later is provided.
By receiving a light emitting command based on the image to be printed from a control unit 20 built in, the surface of the photoreceptor drum 1 is exposed to light to form an electrostatic latent image.

This electrostatic latent image is developed into a toner image by a developing unit 4 provided on the downstream side of the LED head 3 in the direction of drum rotation, and the toner image is transferred onto a sheet of paper fed from a registration roller 10 with timing. transcribed using .

A cleaning device 6 is provided downstream of the transfer corotron 5 in the direction of rotation of the drum, and the cleaning device 6 uses a blade method to remove toner remaining on the surface of the drum.

An erase lamp 7 is provided between the cleaning device 6 and the charging corotron 2 to eliminate residual charges on the surface of the photosensitive drum 1 in preparation for the next image formation.

Paper is selectively fed from the paper cassette 8 or 9 to the registration roller 10 using a paper feed roller 80 or 90, and the size of the paper stored in each paper cassette 8 or 9 is is detected by sensors 81 and 91 (see FIG. 2) using reed switches or the like, for example.

The paper onto which the toner image has been transferred is conveyed to the fixing device 11,
The heat melts and fixes the toner image onto the paper.

A switching claw 12 is provided on the discharge side of the fixing device 11, and when the switching claw 12 is switched counterclockwise, the paper is discharged onto the face-up tray 13 with the toner image on the top. - When the switching claw 12 is switched clockwise, the paper is discharged onto the face-down tray 14 with the toner image facing downward.

The control package 15 is located at the bottom of the printer body.
is provided, and the control package 15 is a second
As shown in the block diagram in the figure, a control section 20 and a frame memory 21 are built-in, and the control section 20 includes an operation panel 1.
Various signals commanded by 6 and detection signals of sensors 81 and 91 for detecting paper size are given. The control unit 20 sends and receives signals to and from the frame memory 21 to create an image based on a paper size instructed by a host (not shown) or a paper size set by default, and sends the created print data to the LED head 3. It looks like this. Here, the final check between the specified paper size recognized by the control unit 20 and the paper size of the cassette/cassette actually installed is usually performed just before one page of data is completed and printing is started. This is because the control unit 20 needs to process the next data while the printer engine unit is performing the printing operation in order to perform the printing process at a higher speed.

FIG. 3 is a diagram showing the storage area of the frame memory 21. For example, when processing B4 size data, the data is expanded using 84 frames memory surfaces.

FIG. 4 is a flowchart showing the control procedure of the control section 20. First, a print image is developed on the frame memory using the paper size specified by the host, and when one page is completed (step ■), the next step is to detect the paper size of the paper cassettes 8 and 9 installed in the printer body. 81 and 9
1 (step ■).

Next, it is determined whether or not the paper size instructed by the host matches the paper size in one of the paper cassettes (step ■). If they match, the image developed on the frame memory is Print on paper of the specified size (step ■).

On the other hand, if the paper cassette has been replaced or there is no paper left, and the loaded paper does not contain the instructions from the host, input is made using the key switch etc. provided on the operation panel 16. It is determined whether or not a forced printing command according to the present invention has been issued by the means (step ①). It is assumed that this forced print command is processed by an interrupt.

When a forced print command is issued, an enlargement or reduction ratio is calculated and determined based on the size developed in the frame memory and the size of the loaded paper (step 2). For example, if the size specified by the host is 84, and there is no paper of this size and A4 size paper is loaded, B4 should be printed to A4 size (a reduction rate of 81% vertically and horizontally is calculated). Ru.

Next, the image developed on the frame memory is enlarged or reduced according to the obtained enlargement/reduction ratio (step
), here, conceivable reduction methods include a logical sum method and a thinning method, but in this embodiment, the method will be described below assuming that thinning is used.

Figure 5 shows that one horizontal line is 81 by using an 8-bit register.
6 shows the transition of the thinning variables for thinning out the developed data. The top of FIG. 5 shows one horizontal line of the expanded frame memory 21, which is 81%
8xo, 81=6.48 is used as a constant to thin out the data.

That is, first, the leftmost bit of the frame memory is placed in the rightmost bit of the 8-bit register. The value of the thinning variable at this time is 6.48, and the integer part is 6 (see FIG. 6).

Next, the thinning variable is decremented by 1, and it is determined whether the integer part is 0 or not. When the bit number is 2, it is 5.48, and since the integer part is 5, the 8-bit register is shifted to the left by 1 bit, and the data of the bit number 2 is set in the rightmost bit. Thereafter, the same process is repeated, and when the bit number is 7, the thinning variable becomes 0.48 and the integer part becomes O. When the integer part is 0, that bit is not set in the register. In other words, the data of bit number 7 has been thinned out. And the value of the thinning variable at this time is 0.48 and 6.4
The value 0.48 + 6.48 = 6.96, which is the sum of 8, is used as a thinning variable and the next process is continued.

Next, when bit number 9 is processed, the 8-bit register becomes full, so this 8-bit data is expanded onto the memory as an 81% reduced image. Thereafter, data is set again starting from the rightmost bit, and by repeating these processes, 81% reduction processing for one horizontal line is completed.

Next, 81% reduction processing is performed in the vertical direction, but this is also processed by thinning out, and the principle is the same as the reduction in the horizontal direction.

When the B4-A4 reduction process is completed in this way, the LE
Send print data to the D head 3 and drive the printer engine to print the developed image (step ■)
.

The above is an example of the processing procedure for printing a B4 developed image on A4 paper by forced printing.

On the other hand, there are cases where enlargement processing is necessary, such as A4-A3.

To briefly explain the enlargement process, first, enlargement by an integral number can be easily processed as shown in the principle diagram of an example of double enlargement shown in FIG. When applying the present invention, it is believed that there is no need for enlargement of more than 200%. In other words,
It is said that it is sufficient to be able to perform enlargement processing of 101 to 200%.

If you want to enlarge the image, first move the expanded image to the 7th
Enlarge to 200% as shown in the figure. Next, by performing a reduction process using the above-mentioned reduction principle, you can easily enlarge the real number times. For example, when performing an enlargement process of 141%, first perform an enlargement process of 200%, and then
It is sufficient to perform reduction processing to /200 xloo = 70.5%.

In this example, B4→^4. Although we have described the case where forced printing is performed for A4 → ^3, it goes without saying that any combination of paper sizes can be freely enlarged or reduced according to the ratio, and it is possible to print on different paper sizes with developed images.

Further, in this embodiment, an LED head is used as the exposure means, but a laser head may be used instead, and the present invention is not limited to electrophotographic printers.

〔effect〕

As described above, in the page printer according to the present invention, even if there is no paper of the specified size, it is possible to edit the size and print on paper of another size, so the operability and utilization of the printer are greatly improved. The present invention has excellent effects such as improved performance.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional view showing the internal structure of a page printer according to the present invention, FIG. 2 is a block diagram of the control system, FIG. 3 is a storage area diagram of the frame memory, and FIG. 4 is a control section of the control unit. A flowchart showing the procedure, FIG. 5 shows the principle of 81% reduction, FIG. 6 shows the explanation of thinning variables, and FIG. 7 shows the principle of 200% enlargement. l...Photosensitive drum 2...LED head 8.9
...Paper cassette 20...Control unit 21...Frame memory 81.91...Sensor patent Applicant: Sanyo Electric Co., Ltd. Agent Patent attorney Noboru Kono Diagrams

Claims (1)

[Claims] 1. A page printer that prints an image on recording paper based on image information input from the outside, comprising: paper size detection means for detecting the size of the loaded recording paper; a comparison means for comparing the image size of the loaded image and the size of the loaded recording paper; , means for editing the size of the image information to the size of the recording paper.