JPH03294875A - image forming device - 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 forming apparatus, and more particularly to an image forming apparatus that performs image exposure using a light emitting element array.

[Prior Art] Many conventional image forming apparatuses form high-quality images by scanning a laser with a polygon scanner.
There is a movement to miniaturize image forming devices using LED arrays (light emitting diode arrays), and USP-47
34734, a light shielding means is disposed between adjacent light emitting elements of an LED array, and the light emitted from the light emitting elements is condensed onto a latent image carrier by a condensing lens array, thereby producing a high-quality image. Image forming apparatuses that form images have been proposed.

[Problems to be Solved by the Invention] However, the above-mentioned conventional technology has the problem that the LED array requires a highly accurate and expensive condensing lens array, resulting in a complicated structure, large size, and high cost. . Further, there is a problem in that the condenser lens array causes a loss of light quantity, and a sufficient quantity of light cannot be obtained unless a large current is passed through the LED array.

SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide a small, low-cost image forming apparatus using a thin light emitting element array with a simple structure. Still another object is to provide an image forming apparatus with high resolution and high image quality.

[Means for Solving the Problems] An image forming apparatus of the present invention is an image forming apparatus that performs image exposure using a light emitting element array to form an electrostatic latent image on a latent image carrier. It is characterized in that image exposure is carried out in close proximity to the latent image carrier.

Further, the image forming apparatus of the present invention is characterized in that the gap between the light emitting element array and the latent image carrier is 500 [μm] or less.

Furthermore, the image forming apparatus of the present invention is an image forming apparatus that image-wise exposes a light-emitting element array to form an electrostatic latent image on a latent image carrier, and image-wise exposes the light-emitting element array by bringing the light-emitting element array into close contact with the latent image carrier. It is characterized by

[Function] According to the above configuration of the present invention, the condensing lens array that was attached to the light emitting element array is omitted, which not only simplifies the structure but also provides a small and thin image forming device. be able to. Moreover, optical loss due to the light transmittance of the condenser lens array can be reduced. Furthermore, a high resolution image can be formed according to the size of the light emitting elements and the adjacent pitch.

Hereinafter, the present invention will be explained in detail with reference to Examples.

[Example] FIG. 1 is a cross-sectional schematic diagram of an image forming apparatus in an example of the present invention, in which a latent image carrier 1 has an organic or inorganic photoconductive material on a conductive support part 2. A photosensitive layer 3 is formed, and after the photosensitive layer 3 is charged using a charger 4 such as a corona charger or a charging roller, a plurality of light emitting elements 5 are arranged in an array in the axial direction of the latent image carrier 1. The light emitting elements 5 of the light emitting element array 6 formed in the same straight line or in a staggered manner are selectively switched according to the image to irradiate the photosensitive layer 3 with light. An electrostatic latent image is formed by obtaining a potential contrast thereon.

The light emitting element array 6 is arranged so that the light emitting elements 5 are close to the latent image carrier 1, and the light emitting element array 6 and the latent image carrier 1
High-resolution image exposure is possible by setting the gap between O and 500 [μm]. In particular, when the light emitting element array 6 is brought into close contact with the latent image carrier 1, the surface potential of at least the vicinity of the contact portion of the light emitting element array 6 is set to a value equivalent to the surface potential of the latent image carrier 1, and light is emitted after image exposure. It is possible to prevent the electrostatic latent image from being destroyed due to contact between the element array 6 and the latent image carrier 1, thereby preventing fluctuations in the potential of the latent image carrier 1 due to contact. Latent image carrier 1 on which an electrostatic latent image is formed
Next, the electrostatic latent image is visualized by adhering toner 8 to the image area by the developing device 7, and the toner is transferred onto the recording paper 10 using a transfer device 9 such as a corona transfer device or a transfer roller. 8 is transferred, and the toner is fixed on the recording paper 10 using heat or pressure to obtain a desired image on the recording paper 10. On the other hand, the toner 8 remaining on the latent image carrier 1 after transfer is removed by the cleaning device 11, and the process starts again after charging. The light path will not get cold even if
The toner collected by the cleaning device 11 is transferred to the developing device 7.
It is also possible to further downsize the image forming apparatus and reduce running costs by providing a toner collecting member (not shown) for reusing the toner. When line images, character images, and solid images were continuously formed on 10,000 sheets using a 300 [DPI] light emitting element array in an image forming apparatus as shown in FIG.
[DPI] Line images are stably formed without line thickening, the resolution of line pair images is sufficiently large, there is no trailing or ground blurring at the edges of the image, and high-temperature solids with an OD value of 1.4 or higher. Images could be formed stably. In addition, the optical path length can be reduced compared to conventional image forming apparatuses using lasers, omitting the polygon motor and optical lens, and the optical path length can also be reduced compared to conventional image forming apparatuses using LED arrays. As a result, image forming apparatuses can be made smaller and cheaper.

In FIG. 1, the latent image carrier 1 can be cylindrical or belt-shaped, and the conductive support 2 is
A conductive metal material such as aluminum can be used, and the photosensitive layer 3 can use an organic or inorganic photosensitive material.

In addition, in FIG. 1, the present invention is not limited only to the configuration shown in the figure. Further, although the arrows indicate the rotation direction of each member, this does not limit the present invention.Furthermore, the developing method can be used regardless of whether it is regular development or reverse development.

FIG. 2 is a cross-sectional schematic view of a light-emitting element array in an embodiment of the present invention. The light emitting section 24 is caused to emit light by switching an electrode (not shown) connected to the section 24. Each light emitting part 24 is provided with a light blocking part 25, and the adjacent light emitting part 2
A protective film 26 is provided to protect the light emitting section 24, and a reinforced section 27 made of tempered glass or the like is provided to prevent light from coming into contact with the latent image carrier. It also strengthens the system. As shown in FIG. 2, a light blocking section 25 is provided in each light emitting section 24 to prevent light leakage to adjacent pixels and maintain high resolution.
By making it sufficiently thick, sufficient resolution can be obtained even if the light emitting element array is disposed with a gap between the light emitting element array and the latent image carrier, and the gap between the light emitting element array and the latent image carrier is 500 [μ
m] If the arrangement pitch is approximately the same as that of the light emitting parts 24, the protective film 26 and the reinforcing part 27 are preferably made of a material with a high refractive index to suppress leakage of light to adjacent pixels and perform high-resolution image exposure. be able to.

Note that in FIG. 2, the layer structure and material of the light emitting element array are not limited to those in this embodiment.
Inorganic semiconductor materials such as S, GaAsP, organic light emitting materials such as TPD (tetraphenylbenzidine) and 'TPAS (tetraphenyldiaminostilbene), and light emitting materials such as semiconductor lasers can be used.

Although the embodiments have been described above, the present invention can be applied not only to the above embodiments but also to a wide range of image forming apparatuses that use magnetic toner, and is particularly effective when applied to printers, copiers, facsimiles, and displays. be.

[Effects of the Invention] As described above, according to the present invention, by bringing the light emitting element array close to or in close contact with the latent image carrier, it is possible to provide an image forming apparatus with a simple structure, small size, and low cost. Further, waste toner can be reused, and an image forming apparatus with low running costs can be provided.

Furthermore, it has the excellent effect of being able to provide an image forming apparatus with high resolution and high image quality.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional schematic diagram of an image forming apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional schematic diagram of a light emitting element array according to an embodiment of the present invention. ...Latent image carrier...Light emitting element...Light emitting element array and above

Claims (3)

[Claims] (1) In an image forming apparatus that performs image exposure using a light emitting element array to form an electrostatic latent image on a latent image carrier, the light emitting element portion of the light emitting element array is brought close to the latent image carrier to perform image exposure. An image forming apparatus characterized by: (2) The image forming apparatus according to claim 1, wherein a gap between the light emitting element array and the latent image carrier is 500 [μm] or less. (3) An image forming apparatus that performs image exposure using a light emitting element array to form an electrostatic latent image on a latent image carrier, characterized in that image exposure is performed with the light emitting element array brought into close contact with the latent image carrier. Image forming device.