JPH04369171A - Picture output device - Google Patents

Abstract

PURPOSE:To relieve the load of the software/hardware by setting an indefinite data caused when line density is converted from that of a picture data of the millimeter system into that of a picture data of the inch system to be a white picture element data forcibly so as to replenish a deficient data quantity due to the line density conversion. CONSTITUTION:A write control section 14 is provided to control the write by a laser beam of a plotter (LD) 13 and provided with a white picture element processing control section 15 and a laser beam (LD) light emission control section 16. The white picture element processing control section 15 replaces an indefinite data for each line caused when a line density control section section 11 applies line density conversion to a picture data from the millimeter system into the inch system with a white picture element data. The LD light emission control section 16 selects an LD light emission control pattern in response to the presence of the line density conversion.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image output device used as a plotter in a facsimile machine, a printer, etc., and more particularly to an image output device that prints out images in response to both millimeter and inch image data. .

0002

2. Description of the Related Art Conventionally, image output devices that draw arbitrary images using binary pixel data of white or black have been widely used. The image is printed out. By the way, in recent years, especially in facsimile machines, in addition to the G3 standard (mm system), the G4 standard (inch system) has begun to spread, and as a result, there are cases where it is necessary to output mm system and inch system images with the same plotter. is increasing.

[0003] In order to output mm-system and inch-system images using the same image output device, the plotter's I/O
Switching the rules to mm-based or inch-based rules is rarely implemented because it is costly. A commonly adopted method is to perform linear density conversion of image data between the mm system and the inch system to deal with the problem data-wise.

0004

[Problems to be Solved by the Invention] However, in such conventional image output devices, the amount of data handled by both G3 and G4 is the same; for example, in the case of A4, the amount of data handled is 1/16[
mm]≈400 dpi mode, 3456 [dots], but if linear density conversion is performed between mm-based image data and inch-based image data, the amount of data will increase or decrease. For this reason, if the amount of data is treated as the same even after conversion, a shift in the center position or undefined data will occur, and if an attempt is made to correct this using software, there is a problem in that the burden on the software increases.

[0005] Furthermore, if the converted data is handled as it is, it does not meet the standard data amount, and in this case as well, there is a problem in that the burden on software processing and hardware increases. Therefore, the invention according to claim 1 forcibly converts the indefinite data generated when linear density conversion from millimeter image data to inch image data into white pixel data.
It is an object of the present invention to provide an image output device that compensates for the lack of data amount due to linear density conversion and reduces the burden on software and hardware.

[0006] Another object of the invention is to provide an image output device that eliminates the center shift of the print position by switching the timing of transmitting image data depending on the presence or absence of linear density conversion. .

[0007]

[Means for solving the problem] The invention according to claim 1 includes:
In order to achieve the above purpose, a line density converter converts the line density for each line between millimeter image data and inch image data, and the image data converted by this line density converter or the An image output device comprising a storage means for storing converted image data line by line, and a plotter outputting an image according to millimeter or inch system image data read line by line from the storage means. The present invention is characterized in that it includes a white pixel conversion control unit that replaces undefined data for each line that occurs when linear density conversion is performed from millimeter image data to inch image data with white pixel data.

Further, in order to achieve the above object, the invention as claimed in claim 2 is a laser beam plotter in which the plotter writes an image on a photoreceptor with a laser beam, and the laser beam is emitted line by line according to image data. An image output device having a light-emitting area, and a pre-emission area and a post-emission area for clearing a photoreceptor with a laser beam before and after the light-emitting area, wherein the pre-emission area corresponds to half of the number of data converted into white pixels. The present invention is characterized in that it includes a laser beam emission control unit that adds a laser beam to the area and subtracts the amount equivalent to half from the post-emission area.

[0009]

[Operation] In the invention as set forth in claim 1 having the above configuration, the undefined data for each line generated when the line density converter converts the line density from millimeter image data to inch image data is converted to a white pixel. The pixel data is replaced with white pixel data by the conversion control unit. Further, in the invention as set forth in claim 2 having the above configuration, there is provided a light emitting region in which a laser beam is emitted line by line according to image data, and a front light emitting region and a rear light emitting region in which the photoreceptor is cleared by the laser beam before and after the light emitting region. A light-emitting area is provided, and a laser beam emission control section adds an amount equivalent to half of the number of data converted to white pixels to the pre-emission area, while subtracting the amount equivalent to half from the post-emission area.

0010

EXAMPLES The present invention will be explained below based on examples. FIG. 1 is a diagram showing a facsimile machine to which an image output device according to an embodiment of the invention as set forth in claim 1 or 2 is applied. First, the configuration will be explained. In the figure, linear density converter 1
1 inputs image data read by a scanner (not shown) or image data from a received facsimile message, and converts the line density for each line between millimeter image data and inch image data. . This linear density converter 1
The image data converted by 1 or the unconverted image data is stored line by line in a page memory 12 serving as a storage means. The plotter (LD) 13 is a laser beam plotter that writes an image on a photoreceptor (not shown) using a laser beam, and writes an image according to millimeter or inch image data read line by line from the page memory 12. Print out.

[0011] The write control unit 14 controls the plotter (L
D) It is provided to control the writing operation using the laser beam 13, and includes a white pixelization control section 15 and a laser beam (LD) emission control section 16. The white pixel conversion control unit 15 replaces undefined data for each line that occurs when the line density is converted from millimeter image data to inch image data with white pixel data. The LD light emission control unit 16 controls a light emitting region in which a laser beam is emitted line by line according to image data, and a pre-light emitting region and a post-light emitting region in which the photoreceptor is cleared by a laser beam before and after this light emitting region. The half of the number of data converted to white pixels is added to the front emission area, while the half of the number of data is subtracted from the after emission area, and the LD emission is performed depending on the presence or absence of linear density conversion. Switch control pattern.

DMA (Direct Memory A)
access) controller 17 is a write control unit 14
Image data is read out from the page memory 12 in response to the operation. The system control unit 18 controls the entire system according to a predetermined control program. Next, claim 1
The operation of the described invention will be explained. The image data handled in this example is 1/16 [mm] of B4 ≒ 40
0 [dpi] mode = 4096 [dots].

First, image data is input from the system side to the line density converter 11 line by line. mm→inch
When converting, the system control unit 18 instructs the linear density conversion unit 11 to turn on the conversion and its ratio. here,
The ratio is inch:mm=63:64. For this reason,
By mm→inch conversion, 4096×63/64=
Inch-based image data for 4032 [dots] is output and written to the page memory 12.

A conceptual diagram of the page memory 12 is shown in FIG. 2(a). Since the image output device of this embodiment specifies the maximum B4 size, one line (main scanning direction) is 4096 [d
ot], the memory space is designated as an area. Therefore, by mm→inch conversion, 4032 [do
The image data decreased to 64[d] at the rear end of one line.
ot] will be left over. This part is shown by the hatched part in FIG. 2(a), and is considered to be undefined data in which 0 or 1 is not determined. Note that when storing mm-based data of A4 size, there will be 4096-3456=640 [dots] left at the rear end.

When a data latent image for one page is created in the page memory 12, the system control unit 18 instructs the DMA controller 17 to read the data per line (Data latent image).
/Line) to transfer the image data line by line from the page memory 12 to the write control unit 14. At this time, the number of data/line to be specified (Data/Line)
is 4096 [dots], which is common to both mm→inch converted data and unconverted data. Therefore, 64 [dots] at the rear end of the line are read out as undefined data.

Therefore, the white pixelization control unit 15 forcibly replaces the trailing end of the line 64 [dots] with white pixel data, and the 4096 [d
Prevent indefinite data from appearing in the image data of [ot]. If mm→inch conversion is not performed, the linear density converter 11 is passed through, and the page memory 12 contains 40 mm.
96 [dots] are written in full and plotted as is.

As described above, in this embodiment, regarding the image output device that converts mm-based data from mm to inch and plots it, the amount of data handled remains unchanged at 4096 [dots] both during conversion and when no conversion is performed. , it is possible to plot using either image data without putting a burden on software control, data control, hardware, etc. In this embodiment, a laser beam plotter is illustrated as the plotter 13, but the laser beam plotter is not essential, and it is possible to use a thermal or impact plotter to output white pixel image data as an image. is also possible.

Next, the operation of the invention as claimed in claim 2 will be explained. If image data converted from mm to inch using the above configuration is assigned to the LD light emission timing in the same way as image data that is not converted, the center of the photoconductor and the center of image data c will be Misaligned. That is, the center of the image data c is shifted toward the tip by 64/2=32 [dots] due to the undefined data.

Therefore, when plotting the converted data, the LD light emission control unit 16 plots the deviation of 32 [dots] from the previous state of the image data state c, as shown in LD control ■ in FIG. 2(b). b, and after the fractional data state c, the state d is subtracted by 32 [dots]. As a result,
It is possible to eliminate the center shift of the image data c while keeping the total status b+c+d=photoconductor width constant.

Note that in the example of FIG. 2(b), L at the time of no conversion is
In D control ■, b state = 48, d state = 48
In the case of [dot], b=80 and d=16 [dot] in LD control (3) in which converted data is plotted. In this way, in this embodiment, the LD control is switched depending on whether or not linear density conversion is performed, and the preceding and succeeding states b and d are changed by the amount that the image data state c of the LD light emitting state is shifted from the center due to the conversion. Because it is aligned with the center of the photoconductor, there is no need to process the data by software processing, etc., and the converted data and the center of the photoconductor can be matched and plotted.

[0021] If you try to process the data using software, in the example of B4 mentioned above, 4096 [do
It is necessary to add 32 [dots] worth of white pixel data in front of the image data of [t] and cut the image data of 32 [dots] at the rear end. Cutting data at the rear end is relatively easy since it is sufficient to reduce the amount read from the page memory 12, but adding data to the front end is a difficult task.

[0022] In addition, in the case of A4, 3456 x 63
/64=3402[dot], so mm→inc
The difference due to h-conversion is 54 [dots], and half of that is 27 [dots]. Normally, the unit of data handled by software is Byte or Word, so 2
7 [dot] does not match this unit and requires operation in bit units. Therefore, the burden on the software becomes enormous.

In this regard, according to this embodiment, there is no burden on the software, and centering can be performed in bit units.

[0024]

As explained above, according to the image output device according to the invention set forth in claim 1, when the linear density converter converts the linear density from millimeter image data to inch image data, Since the undefined data for each line is replaced with white pixel data by the white pixel conversion control unit, the amount of data to be handled can be reduced, regardless of whether the linear density is converted from millimeter data to inch data and plotted, or plotted without conversion. Since this does not change, plotting can be performed using either image data without placing any burden on software control, data control, hardware, etc.

Further, according to the image output device according to the second aspect of the invention, there is provided a light emitting region in which a laser beam is emitted line by line according to the image data, and a photoreceptor is cleared by the laser beam before and after this light emitting region. A front light emitting area and a back light emitting area are provided, and a laser beam emission controller adds an amount equivalent to half of the number of data converted to white pixels to the front light emitting area, while adding the amount equivalent to half of the number of data converted to white pixels to the front light emitting area. This allows the laser beam emission control to be switched depending on the presence or absence of linear density conversion, and the center of image data of inch data converted from millimeter data can be plotted to align with the center of the photoconductor. .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a facsimile device to which an image output device according to an embodiment of the invention as set forth in claim 1 or 2 is applied.

FIG. 2 is a diagram for explaining white pixelization control and LD light emission control; FIG. 2(a) is a conceptual diagram of a page memory, and FIG. be.

[Explanation of symbols]

11 Linear density converter 12 Page memory (storage means) 13 L
D (plotter) 15 White pixelization control section 16 LD light emission control section

Claims (2)

[Claims] 1. A linear density converter that converts line density for each line between millimeter-based image data and inch-based image data, and an image data that is converted by the linear density converter or an image that is not converted. An image output device comprising a storage means for storing data line by line, and a plotter for outputting an image according to millimeter or inch image data read line by line from the storage means. An image output device comprising: a white pixel conversion control unit that replaces undefined data for each line generated when line density conversion is performed from image data to inch-based image data with white pixel data. 2. The plotter is a laser beam plotter that writes an image on a photoconductor using a laser beam, and includes a light emitting area that emits a laser beam line by line according to image data, and a laser beam that writes an image on the photoconductor before and after this light emitting area. An image output device having a pre-emission area and a post-emission area to be cleared, wherein an amount equivalent to half of the number of data converted into white pixels is added to the pre-emission area, and an amount equivalent to half of the number of data converted to white pixels is added from the after-emission area. 2. The image output device according to claim 1, further comprising a laser beam emission control section for reducing the amount of light.