JPH0375856B2 - - 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 development and fixing processing. 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. Development that causes . 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.

Incidentally, Fig. 2 shows the situation when a laser beam whose radiant emittance has a Gaussian distribution is incident on the photoreceptor 41, and is illustrated by the trajectory of the ray of maximum radiant intensity I _p . . 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 shown in B ₁ →A ₁ →B ₂ →..., and as a result, the actual exposure diameter on the photoreceptor 41 is 10 to 20% larger than the diameter of the incident laser beam, 2W. I become confused. Here, the diameter w of the laser beam is the beam radius at a point defined by I/I _p =e ^-z (I: average radiation intensity). Further, the photoreceptor 41 is made of a photosensitive layer or a photoconductive layer of Se-based, CdS-based, etc., and usually has a thickness of about 30 to 80 μm.

Further, as the photoreceptor 41, a conventionally known organic photoconductor can be used, and the organic photoconductor may be a single layer or a stack of a charge generation layer and a charge transport layer. charge generation layer,
The thickness of the charge transport layer is generally 0.1 to 2 μm, respectively.
It is about 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, when exposing the photoreceptor using a light beam in a long wavelength range with poor light absorption inside the photoreceptor, for example, a laser beam emitted from a semiconductor laser, As shown in FIG. 3, a photosensitive recording medium is used in which a layer 43 made of a substance with a large light absorption number is provided between a photoreceptor 41 and its base 42.
Note that this light absorption layer 43 is mainly formed of, for example, black conductive carbon, and if the resistance value of the light absorption layer 43 becomes high, it will adversely affect the sensitivity of the photoreceptor 41. It is desirable to minimize the resistance value by molding a material with a resistance of 10 ³ Ω·cm or less to a thickness of 1 μm or less.

By using a photosensitive recording medium formed in this manner, 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 light absorption layer 43. As a result, the base 4, such as aluminum, becomes almost absorbed.
Reflection of light on the two surfaces is suppressed, and multiple reflection development that occurs inside the photoreceptor 41 as in the prior art can be effectively prevented.

FIG. 4 also shows that when the light absorption layer 43 is provided on the surface of the base 42, the base 42 is formed in order to increase the adhesive force between the two and to further reduce the internal resistance value of the light absorption layer 43. This shows a photosensitive recording medium constructed by forming irregularities on the surface and adhering a light-absorbing material thereto. At this time, the roughness of the unevenness formed on the surface of the base 42 is
It is desirable that the thickness be 1 μm or less.

Effects As described above, in the image recording method according to the present invention,
When recording an image by exposing a photosensitive recording medium to an optical signal carrying image information,
Using a photosensitive recording medium in which a layer is formed between the photoreceptor and the base to prevent specular reflection of incident light, multiplexing within the photoreceptor is possible even when exposure is performed using an optical signal with a relatively long wavelength. It is designed to prevent reflections from occurring, so it does not cause the apparent exposure diameter to become large, resulting in blurred images or poor resolution, and allows high-quality image recording to be performed at all times. It has the excellent advantage of being able to

[Brief explanation of drawings]

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 occurring inside a photoreceptor. Figures 3 and 4 are diagrams showing the state of multiple reflections of incident light. 1A and 1B are side sectional views each showing a configuration example of a photosensitive recording medium provided with an absorption layer. 41...Photoreceptor, 42...Base, 43...Light absorption layer.

Claims (1)

[Scope of 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. An image recording method in which the latent image is then visualized with toner and the developed image is transferred to a transfer medium, characterized in that a light absorption layer is provided between the base and the photoreceptor. Recording method. 2. The image recording method according to item 1 above, characterized in that unevenness is formed on the surface of the base.