JPH0526191B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an image recording method using an optical scanning method in which an image is recorded by performing optical scanning on a photoreceptor based on external digital image information.

Prior Art Conventionally, as a specific implementation means of this type of image recording method, as shown in FIG. modulate the modulated laser beam, and pass the modulated laser beam through an imaging lens,
The light is sent onto the photoreceptor drum 4 through an optical system 2 consisting of a light deflector such as a galvanometer mirror, and exposed. The image is recorded on transfer paper (not particularly shown) by performing a fixing process. In the figure, 5 indicates a charging section, and 6 indicates a developing section. This method of recording images using laser light has good light condensing properties, good light utilization efficiency, can directly apply light modulation, and is compact and low in power consumption. It also has many advantages, such as being able to form an array of laser diodes and performing high-speed writing.

Normally, when writing on a photoconductor using optical information,
The sensitivity of the photoreceptor decreases as the wavelength of light becomes longer than about 650 nm, so it is desirable to use a writing light source whose emission wavelength is less than the above wavelength.

However, the emission wavelength of the semiconductor laser 1 is about 700 to 750 nm, even if it is short, and the sensitivity to the photoreceptor is not very good, and when light of such a wavelength is incident on the photoreceptor, as shown in FIG. Drum base 42 due to less light absorption inside 41
(usually made of aluminum), the light is reflected, reaches the surface of the photoreceptor 41, and is further reflected there, which is called multiple reflection inside the photoreceptor 41. This phenomenon begins to occur. Therefore, when long wavelength light is incident on the photoreceptor 41,
The photoreceptor 41 due to multiple reflected light inside it.
As a result, the actual exposure diameter becomes larger than the diameter of the incident light, resulting in a recorded image becoming blurred or having poor resolution, resulting in a decrease in image quality. In particular, when the laser beam is main-scanned on the photoreceptor 41 using a galvano mirror or the like, the angle of the laser beam incident on the photoreceptor 41 becomes large at the end of the main scan, resulting in the above-mentioned problem. The disadvantage is that the actual exposure diameter due to multiple reflections becomes the maximum, and the quality of the recorded image at that portion is significantly degraded.

Note that FIG. 2 shows the state when a laser beam with a Gaussian radiant emittance is incident on the photoreceptor 41, and is illustrated by the locus of the ray of maximum radiant intensity I ₀ . . Normally, the surface of the aluminum drum base 42 has a reflectance of about 0.6 to 0.8, and the laser light incident on the photoreceptor 41 is
Multiple reflections occur internally as B ₁ →A ₁ →B ₂ →..., and as a result, the actual exposure diameter on the photoreceptor 41 is increased by 10 to 20% compared to the diameter of the incident laser beam, 2W. It becomes a thing. Here, the diameter W of the laser beam
is the beam radius at the point defined by I/I ₀ =e ⁻² (I: average radiant intensity). The photoreceptor 41 is made of a photosensitive layer or a photoconductive layer of Se-based, CdS-based, etc., and its thickness is usually 30 to 80 μm.
It is often used to some extent.

Further, an organic photoconductive layer can be used as the photoreceptor 41, and examples of the organic photoconductive layer include a charge generation layer,
A stacked charge transport layer may also be used. Generally, the thickness of the charge generation layer and the charge transport layer are each
They are approximately 0.1 to 2 μm and 5 to 50 μm.

Purpose The present invention was made in consideration of the above points, and
An object of the present invention is to provide an image recording method that can record a high-quality image by suppressing the effects of multiple reflections that occur inside a photoreceptor when the laser beam is incident.

Configuration An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In the image recording method according to the present invention, the photoreceptor is exposed to light using a long wavelength light beam with poor light absorption inside the photoreceptor, for example, a laser beam with a wavelength of 700 nm or more emitted from a semiconductor laser. I try to make it possible.

FIG. 3 shows an example of the structure of a photosensitive recording medium used in the image recording method according to the present invention.
From 0.1 to the boundary between the photoreceptor 41 and the base 42
The base 42 is formed by forming fine irregularities of about 1.0 μm.
The surface of the photoreceptor 41 is formed in a state close to a uniformly diffused reflective surface, which is desirable as a reflective surface with good light diffusivity, to prevent multiple reflections from occurring inside the photoreceptor 41 due to light diffusion. That is, as shown in FIGS. 2 and 3, the fine irregularities on the base surface are exposed to a wavelength of 700 nm carrying image information.
Multiple reflections inside the photoreceptor are prevented by providing a light diffusion surface that is close to a uniform diffusion reflection surface for the incident laser light from the semiconductor laser described above.

As a method for forming the unevenness on the surface of the base 42, generally known methods such as sandblasting, cutting, grinding, etc. can be used.
When the base is drum-shaped, cutting and grinding methods are generally used.

By using a photosensitive recording medium formed in this way, even if the photoreceptor 41 is exposed to long wavelength light with relatively low sensitivity, the light that passes through the inside of the photoreceptor 41 will not reach the surface of the base 42. The specular reflection direction component is significantly reduced by being diffused by the uneven portion, and the photoreceptor 4
This makes it possible to reduce multiple reflected light that occurs inside the device.

Effects As described above, in the image recording method according to the present invention,
When an image is recorded by exposing a photosensitive recording medium comprising a photoreceptor including a photoconductive layer on a base to an optical signal of a laser beam carrying image information, a layer of 0.1 to 1.0 μm is deposited on the surface of the base. By making the base surface a light diffusing surface that is close to a uniformly diffused reflection surface for incident laser light from a semiconductor laser with a wavelength of 700 nm or more on which image information is loaded, it is possible to This prevents multiple reflections from occurring inside the photoconductor even when exposure is performed using a long-wavelength optical signal, and unlike conventional methods, the apparent exposure diameter becomes larger and the image becomes blurred or its resolution becomes worse. It has the excellent advantage that high-quality image recording can always be performed without causing any deterioration of the image quality.

[Brief explanation of the drawing]

Figure 1 is a simplified configuration diagram showing an image recording device using a general optical scanning method, Figure 2 is a diagram showing the state of multiple reflections of incident light that occurs inside the photoreceptor, and Figure 3 is a diagram showing uniform diffusion on the base surface. FIG. 2 is a side cross-sectional view showing an example of the configuration of a photosensitive recording medium in which a light-diffusing surface close to a reflective surface is formed. 41...photoreceptor, 42...base, 421...
Light diffusive reflective surface.

Claims (1)

[Claims] 1. An electrostatic latent image is formed on a photosensitive recording medium comprising a photoreceptor including a photoconductive layer on a base by uniformly charging it and exposing it to laser light carrying image information; In an image recording method in which the image is visualized with a toner and the image is transferred to a transfer medium, fine irregularities of approximately 0.1 to 1.0 μm are formed on the base surface, and the base surface is exposed to a wavelength at which image information is placed. It is characterized by having a light diffusing surface that is close to a uniformly diffused reflecting surface for incident laser light from a semiconductor laser of 700 nm or more, so that multiple reflections due to exposure to the laser light do not occur inside the photoreceptor. Image recording method.