JPH0456463A - Picture recorder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image recording apparatus that scans light from a light source on a photoreceptor to display and record a desired image as a set of dots.

U. Prior Art Conventionally, this type of image recording apparatus, such as a so-called digital copying machine or a laser printer, forms an image using a collection of minute light dots and records the image. Naturally, the smaller the dot size, the more detailed and faithful the image can be obtained. In general, the dot size (resolution) is the number of dots per inch (dp).
Represented by i. At 300dpi, there are 300 dots in 1 inch. The diameter of the dots is approximately 85 μm.

In order to obtain a solid black image in such an image recording apparatus, all dots are turned on, as if black stones were placed on all the holes of the board, as shown in FIG. 11(a). The thinnest line is a line with a width equal to one dot, which is formed by arranging dots in a row.

[Problems to be Solved by the Invention] However, in the above-described image recording device, if an attempt is made to increase the resolution by reducing the dot diameter (Fig. 11(b)
)) There was a problem in that the density of solid black decreased, and conversely, when the diameter of the dot was increased to increase the density of solid black (FIG. 11(C)), the resolution decreased.

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide an image recording apparatus that achieves both high density and high resolution in solid black.

[Means for Solving the Problems] In order to achieve this object, in the image recording apparatus of the present invention, the dots are composed of main dots and sub-dots, and the sub-dots fill gaps between four adjacent main dots. It is recorded in a position that will be filled in.

[Embodiment 1] Hereinafter, an embodiment in which the present invention is applied to a laser printer will be described with reference to the drawings.

FIG. 2 is a block diagram showing the configuration of the laser printer of this embodiment. The laser printer of this embodiment has a main controller 2.
0, and a printing device 30 that prints figures on printing paper, which is an output medium, and the main controller 20 includes CPU10. Control ROM II, work RAM 12, page memory 13,
It includes an interface 14 and a bus 15 that connects them.

Next, the printing device 30 will be explained. FIG. 1 is a perspective view of the printing device 30. The lights from the main light source 31 and the auxiliary light source 32 are combined by a half mirror 33, reflected by a polygon mirror 39, passed through an fθ lens 35, and scanned on a photoreceptor drum 36. Main light source 31 is main line data 1
6, and the auxiliary light source 32 is driven by the auxiliary driver 4 based on the auxiliary line data 17.
7. An LD (laser diode) or the like may be used as both the main and auxiliary light sources. Further, the light from both light sources is arranged so that the dot of the auxiliary light source 32 is placed in the center of the four dots of the main light source 31 as shown in FIG. When considered as a 300 dpi laser printer, the dot diameter of the main light source on the photoreceptor is 90 μm1 The dot diameter of the auxiliary light source is 40 to 90 μm.
Approximately μm is appropriate.

Next, the action will be explained.

Image information signals from the computer are sent to the interface 14
sent to. The information sent to the interface 14 is expanded into the page memory 13 as 0N10FF information by the CPU 10 while referring to the control ROM II. This 0N10FF information in the page memory 13 becomes the basis of the ON10FF of the main light source 31, that is, the main line data 16. The control ROM 11 stores an auxiliary line data processing program as shown in the flowchart of FIG. By executing this program, one line of auxiliary line data 17 is created from at least two lines of main line data 16. This one line worth of auxiliary line data 17 is stored in the work RAM 12.

FIG. 4 shows an example of the inside of the page memory 13. In order to simplify the explanation, an example will be shown in which one page is composed of 20×20 dots.

FIG. 5 is an example showing the state at each step in the work RAMI2. The auxiliary line data creation process will be described below with reference to FIGS. 3 to 5.

This program starts with a print start command from the computer (step S1, hereinafter referred to simply as S1, and the same applies to other steps).

At this time, the main line data 1 has already been stored in the page memory 13.
6 is stored as shown in FIG. Then, for each bit in order from the upper left, the status of the surrounding bits is checked and auxiliary line data 17 is created according to the status. A step-by-step explanation will be given below.

S2 is the initial setting. n=1 refers to the top row in FIG.

S3 is still the initial setting. Page memory 13 horizontally 1
Work RA that stores auxiliary line data corresponding to a line
All MI2 contents are set to O. This is shown in Figure 5 (a
) corresponds to the state.

S4 is the same initial setting as S2. m=1 refers to the leftmost column in FIG.

S5 is a judgment section. When n=m=1, bm, n=b
1,1. bl, 1 refers to the bit in the 1st row and 1st column.

Here, if the reference bit (bl, 1), the bit to the right (b2, 1), the lower right bit (b2, 2), and the bit directly below (bl, 2) are all 1 (ON), then Y
e s, if any one is O (OFF), then N.

Make a judgment. Here, b 1,1= 01b2.1
= 1, b 2, 2 = 1, b 1, 2 = O, so No
Therefore, S6 is skipped, but since all bits are set to 0 in S3, 51=0.

S7 is a judgment unit that determines whether the end of the line has been reached. If it has reached the end of the line, it will be Yes, if it has not yet, it will be No. Since the answer is No here, proceed to 88.

In S8, the target bit is moved one bit to the right and the process returns to S5 (m=m+1). At this time, since m=2 and n=1, a determination as described in 85 is made based on b2.1. b2,1=1, b3.1=1, b3゜2=1, b
Since 2,2=1, the determination is Yes and the process advances to S6. Currently m=2, so 81=1 in the work RAM 12 is set. This corresponds to the situation shown in FIG. 5(b).

In this way, until it is determined Yes in S7 (in this example, m
= 20) Steps S5 to 88 are repeated until the workpiece R
110 is set in AM12. By the way, O columns and rows are added in advance to the right side of the rightmost column and further below the bottom row of the page memory 13.

With this, even when the reference bit reaches the rightmost or bottommost position of the page memory 13, it can be compared with these virtual data (as a result, all the bits and sotos of the auxiliary line data become O at this time).

If the determination is Yes in S7, that is, when the auxiliary line data for the horizontal digits is completed (FIG. 5(c)), the process advances to S9. In S9, the data stored in the work RAM 12 is output to the printing device 30.

The relationship between the main line data 16 and this auxiliary line data 17 will be described later.

When the output ends in S9, the process advances to 810. S10 is a determination unit that determines whether the last line has arrived. If you have reached the last line, Yes, if not yet, N.

becomes.

If the SIO determines No, the process proceeds to Sll.

In Sll, the target row is shifted down by one and the process returns to S3.

At S3, all data stored in the work RAM 12 is set to O. Then, after S4, again from S5 to 8
8 is repeated. In this way, the above steps are repeated until a Yes determination is made in S10, that is, until all bits have been examined. The auxiliary line data 17 created from the example of FIG. 3 in this way is shown in FIG.

However, as described above, these auxiliary line data 17 are output when one digit is completed and are cleared one after another, and are not stored in a unified form as shown in FIG. If a large-capacity memory is prepared here, it is possible to create one page's worth of auxiliary line data and then output it at once.

Here, the relationship between the main line data 16 and the auxiliary line data 17 will be explained. As described above, when the auxiliary line data 17 for one horizontal line is stored in the work RAMI 2, the auxiliary line data 17 is output to the printing device 30. In the printing device 30, the auxiliary line data 17 is sent to an auxiliary driver 47.

At this time, the main line data 16 is also sent to the main driver 46 at the same time based on the judgment of the CPU10. In this embodiment, since the irradiation position of the auxiliary light source is determined by shifting the optical axes of the main light source 31 and the auxiliary light source 32, the clocks that determine the irradiation timing of the main light source and the auxiliary light source may be the same.

In other words, the data in the first row of FIG. 4 and the first row of FIG. 6 are sent to the respective drivers and printed at exactly the same timing.

FIG. 7 shows the result of printing the data shown in FIG. 3 using the laser printer of this embodiment. FIG. 8 shows the result of printing the same data using a conventional device. It can be seen that, compared to conventional devices, in this device, the dot diameter of the main light source does not need to be made larger than necessary and can be made to an appropriate size, so that the figure does not become thick as in the conventional device. Furthermore, FIG. 9 shows the results of printing 1 dot 1 space line and 2 dot 1 space line using this apparatus and the conventional apparatus. FIG. 5(b) shows the results printed by the conventional device, and FIG. 2(a) shows the results printed by the present device. It can be seen from this that even with the same dot spacing, the present apparatus can provide an output image with higher resolution.

As is clear from the detailed description above, in the laser printer of this embodiment, the dots are composed of main dots and sub dots, and the sub dots are positioned so as to fill the gap between four adjacent main dots. Since the dots are recorded, high-density solid black can be obtained without increasing the diameter of the main dot, and it is possible to achieve both high solid black density and high resolution.

It should be noted that the present invention is not limited to the embodiments described above, and modifications can be made without departing from the spirit thereof.

For example, in addition to laser printers, the present invention also applies to digital copying machines,
Furthermore, the invention is not limited to those electrophotographic systems, but can also be applied to image recording apparatuses using a photosensitive pressure-sensitive recording paper such as a one-sided Cykara system or a silver salt photographic system.

[Effects of the Invention] As is clear from the above detailed description, in the image recording apparatus of the present invention, the dots are composed of a main dot and a sub-dot, and the sub-dot fills the gap between four adjacent main dots. Since the recording is performed in a filling position, it is possible to obtain solid black with high density without increasing the diameter of the main dot, and it is possible to achieve both high density of solid black and high resolution.

[Brief Description of the Drawings] Figures 1 to 10 show embodiments embodying the present invention. Figure 1 is a perspective view of a printing device, and Figure 2 is a laser printer to which the present invention is applied. A block diagram showing the configuration of
Figure 3 is a flowchart of the program in the control ROM,
FIG. 4 is an explanatory diagram of bit information in page memory, FIGS. 5(a) to (C) are explanatory diagrams of states in work RAM, and FIG. FIG. 7 is an explanatory diagram showing the result of printing the data in FIG. 4 using the device of the present invention, and FIG. 8 shows the result of printing the data in FIG. 4 using the conventional device. Explanatory drawings, FIGS. 9(a) and (b) are explanatory drawings showing the results of printing thin lines using the device of the present invention and the conventional device, and FIGS. 10(a) and (b) are diagrams showing the results of printing thin lines using the device of the present invention and the conventional device. FIG. 3 is an explanatory diagram showing the positional relationship of dots on a photoreceptor. Further, FIGS. 11(a) to 11(C) are explanatory diagrams showing the relationship between dot diameter and printing results in a conventional image recording apparatus. In the figure, 31 is a main light source, 32 is an auxiliary light source, and 36 is a photosensitive drum. Figure 4 Figure 5 (a) (b) (C) Figure 9 (a) (b) Figure 1110 (a) (b) @Figure 11 (a) (b) (C) "F'l 1WF- Q sentence ○ S00 μ heshi

Claims (1)

[Claims] 1. An image recording device configured to scan light from a light source on a photoreceptor to display and record a desired image as a set of dots, wherein the dots are composed of main dots and sub-dots. An image recording apparatus characterized in that the sub-dots are recorded at positions that fill gaps between four adjacent main dots.