JPS58152269A - Optical recording system - Google Patents

Abstract

PURPOSE:To eliminate uneven exposure and to obtain reproduced picture images having good quality, by setting the intensity of a light so as to satisfy the specific relation between the diameter of the light beam and the intervals of scanning lines. CONSTITUTION:In an optical recording system which forms exposure patterns by modulating the intensity of the light beam in a gauss distribution and scanning the surface of a photoreceptor with said beam, the surface of the photoreceptor is exposed so as to satisfy the relation 1.3<=d/P<=1.9 between the diameter (d) of the laser beams (the distance from the center of the laser beam up to the point where the power decreases to 1/e<2> the peak value) and scanning intervals P. For example, when the surface is exposed at d/P=1.6, the density E of the exposure energy on the photoreceptor is distributed nearly in a flat rectangular shape as compared to the conventional case of exposure at d/P=1; therefore, the reproduced quality having no uneven exposure and having good quality are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (4) Technology of the Invention Public Funding The present invention relates to an optical recording system, and more particularly to an optical recording system in which a Gaussian distributed light beam is used to scan the surface of a photoreceptor to form an exposure pattern.

(2) Background of the Technology A recording method is known in which exposure is performed by modulating the intensity according to the pattern to be recorded by scanning a Gaussian distributed light beam.

C) Prior art and problems FIG. 1 is a diagram showing the configuration of an electrophotographic system as an example of such a recording method, in which 1 is a laser light source, 2 is an optical modulator, 8 is an optical deflector, 4 is an etc. A lens system forming a speed scanning optical system, 5 a photosensitive drum, and q a recording paper.

The light from the laser light source 1 is emitted depending on the pattern to be recorded.
The light is modulated by the light modulator 2, enters the light deflector 8 and is deflected, and then enters the lens system 4 and is irradiated with the photosensitive drum 6).

FIG. 2 shows the scanning interval P on the photoreceptor and the exposure state, which was conventionally set at 1/p-71.

In the example of the electrophotographic method shown in FIG. 1, the photosensitive drum 5 is formed of a photosensitive member.

l! Figures 8 and 4 are the broken lines of Figure 2 and B, respectively.
-B' is a diagram showing the exposure energy density distribution along 1. This is for the case where d/p=1. In both of these figures, the horizontal axis represents the position on the -light body, and the vertical axis represents the exposure energy density E.

As is clear from the figure, the energy density is large at positions 81', 81', 8.1... above the scanning line 81.8 Snow, 8 m..., and at the position Ts between the scanning lines.

The energy density is smaller at Tm and Tt.
This energy difference Em*x-Esaim becomes a thick number.
Ts, Ts, Ts, . . . had the drawback that the amount of exposure light was insufficient and exposure unevenness occurred, making it impossible to obtain a high-quality reproduced image.

ρ) Purpose of the Invention The present invention has been made in view of the above-mentioned drawbacks of the conventional art, and an object of the present invention is to provide an optical recording system that can produce high-quality reproduced images with little exposure unevenness.

(1) Structure of the Invention According to the present invention, in an optical recording method in which an exposure pattern is formed by intensity modulating a Gaussian distributed light beam and scanning the surface of an exposed object, the light intensity of the fin recording light beam is at the beam center. The beam diameter d defined as 17.1 and the interval P between the scanning lines are set to satisfy the relationship 1.8≦a/p≦1.9. This is achieved by providing an optical recording method.

0 @ Ming's Embodiment Preferred embodiments of the present invention will be described in detail below with reference to the drawings.

Before explaining the embodiments, the basic idea of the present invention will be explained.

On the photoreceptor! -yM11A system, and consider a laser beam with a laser power of io that scans in the direction of one wheel at a speed.

If the radius of the laser beam is W (distance from the center of the laser beam to the point where the peak power value is 1/2), the scanning aperture is P, and the number of scans is 8, then the point on the photoreceptor surface (x, y
) at exposure energy density 1(x.

7) is expressed by the following equation.

/vl) , in the same figure, the exposure energy density on the exposed scanning lines B1', am'... is the exposure energy density between the scanning lines when adjacent scanning lines are exposed.
m, the exposure energy density on the unexposed quantitative line sandwiched between the exposed scanning line and the button is Ebo.

FIG. 4 shows the exposure energy density distribution when exposure is performed for each scanning line, and the maximum value of the exposure energy density in this case is defined as Emax.

The ideal state of exposure energy density distribution is Emax=Em
Although it is a rectangular distribution with in=E'max==l and Ebo4==1, the actual distribution is a convex distribution as shown in Figure 8.

Here, the evaluation function f is defined by the following equation.

f=k>mu-klB+ksC・・・・・・・・・C)
Here, human is a parameter related to the height of the exposure energy density distribution, and B is a parameter related to the uniformity of energy at the exposed area.
C is a parameter related to the height of the exposure energy density distribution during ridge exposure; 10. kl! ,
kl ii is a coefficient with a value of 1 for each parameter, and the larger the coefficient C is, the smaller the coefficient B is, the less uneven exposure there is.In the end, the larger the evaluation function f is, the less uneven exposure is. Figure 6 shows the coefficients M, B, and C.
shows the characteristics of

The state where the evaluation function f is maximum is the state where the exposure energy density distribution is optimal.

Evaluation function f when each coefficient is klffikl=kl
The characteristics of ssm are shown, and when d/p-L55, the evaluation tie number j is the maximum value! =1.57.

Further, the range in which the value of the evaluation function f is 90% or more of the maximum value is expressed by the equation (Xun).

1.8≦Direct/p≦1.9 (4)
Therefore, by setting the relationship between the scanning interval P and the beam diameter d in the sub-scanning direction to a degree that satisfies the following equation, it is possible to perform high-quality exposure without exposure unevenness.

Next, examples of the present invention will be described.

Exposure energy density distribution along Moum+, B-B' on the exposed body when exposing the pattern shown in Figure 112 with d/p=11 is 1171! ! ! 8, the horizontal axis indicates the position on the surface of the exposed object, and the vertical axis indicates the exposure energy density.

When exposed using the conventional method (d/p)-1 (Fig. 118,
Compared to Figure 114), the coefficient M increases from o.42 to 0.88, the coefficient B decreases from 1.16 to 0.17, and the coefficient C increases from 1.16 to 0.17.
The exposure energy density distribution decreases from 67 to 0.91, and the exposure energy density distribution becomes close to a flat rectangular distribution. Therefore - the exposure energy density between each scanning line at the exposed part of the light surface ′
The difference between the exposure energy density on the scan line and the exposure energy density on the scan line is small, and the exposure energy density in the dark area of the scan line is close to the field value required for development.

For this reason, the exposure energy density distribution on the light body becomes a binary level of exposed areas and unexposed areas, and the exposure energy density in the darkness of the scanning line, which is seen in the case of exposure by conventional methods, makes development possible. There is no development in which the output is disturbed because the threshold value is not met.

(Q. Effects of the Invention) As is clear from the above explanation, the optical recording method according to the present invention has a relationship between the scanning line interval and the light beam diameter set as shown in the ship formula, so there is no exposure unevenness in the exposed area and high quality is achieved. A reproduced image is obtained.

[Brief explanation of drawings]

Figure 1 is a device configuration diagram of a laser printer, Figure 2 is a d/p
-1 exposure energy density distribution diagram, Figure 8 and l
FIG. 14 is an energy density distribution diagram of the conventional method, FIGS. 115 and fls are characteristic diagrams of the coefficient IBIC and the evaluation function f, and FIGS. 7 and 118 are exposure energy density distribution diagrams according to the embodiment of the present invention. 1 is a laser light source, 2 is a light modulator, 8 is a light deflector, 4 is a lens system, 6 is an exposure drum, as, 8m. S... indicates a scanning line. 8 11 A'B' I/10 1/)
Lee −
〇1・Indication of I≦11 Showa 57+1 Mochiro Inn 1 No. 34B;
L place Kanayo prefecture Kawasaki Yamanaka + 9 ward IIJ・II Kawayo 101
Address 5 (5221 name Fujitsu Ltd. 4 representative!, IP, uli Kawasaki Yamanaka, Kanayo Prefecture, f +

Claims (1)

[Claims] In an optical recording method in which a Gaussian distributed light beam is intensity-modulated and scanned on the surface of a light body to form an exposure pattern, a beam defined by a value such that the light intensity of the light beam is x/i' at the beam center. The diameter d and the spacing P between the scanning lines are 1.8.
An optical recording method characterized by being set to satisfy the relationship: ≦67p≦1.9.