Photocopying – Projection printing and copying cameras – Detailed holder for original
Reexamination Certificate
1999-05-12
2001-04-24
Rutledge, D. (Department: 2851)
Photocopying
Projection printing and copying cameras
Detailed holder for original
C355S076000, C396S617000, C396S620000
Reexamination Certificate
active
06222617
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus and an exposing apparatus which exposes a sheet-shaped light sensitive material fixedly held on an outer peripheral surface of a drum rotating at high speed on the basis of image data.
Conventionally, in the exposing apparatus, as a method of fixing the sheet-shaped light sensitive material on a drum, a method based on electrostatic adsorption, a method of fixing by holding mechanically an end of the sheet-shaped light sensitive material, a method of fixing by holding an end with an adhesive tape or the like, and a method of fixing by air suction are known.
Recently, in the exposing apparatus stated above, to reduce exposure time has been demanded.
As a result of studying to reduce exposure time by making the rotational speed of the drum higher, it has been found that image unevenness tends to happen in the method of fixing an end of the sheet-shaped light sensitive material as the conventional technique.
Especially, in the case that the sheet-shaped light sensitive material is a silver halide photographic light sensitive paper, a part of the central portion of the silver halide photographic light sensitive paper sometimes floats up and the floating section shifts out of the depth of field of a light beam, because the stiffness of the silver halide photographic light-sensitive paper is low, differing from a photographic film.
Further, in the case that a paper size is greater than A3 size, since a region distant from the ends is wider, a part of the region tends to float up to an extent that the floating section shifts out of the depth of field of a light beam.
Furthermore, when producing a color proof, if the image unevenness as that stated above takes place, there may be a problem that the reliability as a color proof is lowered.
SUMMARY OF THE INVENTION
The invention has been achieved in view of the aforesaid points, and its object is to obtain an image of high quality on the drum rotating at a high speed.
In addition, the object is to obtain a reliable color proof.
Further, the object is to easily eliminate a light sensitive material falling from the drum in an unlikely event when the drum is rotated at high speed, and to prevent members located in the vicinity of the drum from being damaged by the falling light sensitive material.
Furthermore, the object is to conduct a maintenance work safely such as an eliminating work for a jamming light sensitive material.
The object of the present invention can be attained by the following structure.
An exposing apparatus comprises:
a drum to fixedly hold a sheet-shaped light sensitive material onto an outer peripheral surface thereof by suctioning;
a rotating driving means capable of rotating the drum at a rotational speed not less than 1200 rpm; and
an exposing means for exposing on the basis of image data the light sensitive material fixedly held on the outer peripheral surface of the drum rotated by the rotating driving means.
The object of the invention can be also attained by the following structures corresponding to preferable embodiments shown below.
(Structure 1) An exposing apparatus comprising a drum which holds fixedly, on its outer circumferential surface, a sheet-shaped silver halide photographic light-sensitive paper through air suction, a rotating driving means which rotates the drum, and an exposing means which exposes the sheet-shaped silver halide photographic light-sensitive paper held fixedly through air suction on the drum rotated by the rotating driving means with a light beam, wherein the exposing means can expose, with the light beam, the sheet-shaped silver halide photographic light-sensitive paper held fixedly through air suction on the drum rotated at the speed of 1200 rpm or more by the rotating driving means.
(Structure 2) The exposing apparatus according to Structure 1, wherein the exposing means can expose, with the light beam, the sheet-shaped silver halide photographic light-sensitive paper held fixedly through air suction on the drum rotated at the speed of 1200 rpm or more by the rotating driving means, even when the sheet-shaped silver halide photographic light-sensitive paper is greater than A3 size.
(Structure 3) The exposing apparatus according to Structure 1 or Structure 2, wherein plural holes for air suction are provided on the drum and there is provided a pump for air suction through the holes for air suction.
(Structure 4) The exposing apparatus according to either one of Structure 1 through Structure 3, wherein the exposing means has an optical head which emits plural beams for irradiating the sheet-shaped silver halide photographic light-sensitive paper and a moving means which moves the optical head in the direction along the axis of the drum.
(Structure 5) The exposing apparatus according to either one of Structure 1 through Structure 4, wherein the sheet-shaped silver halide photographic light-sensitive paper is a color photographic light-sensitive material, the exposing means is means for exposing with light beam of plural different wavelengths, the half tone dot image data are those obtained from image data for electronic plate-making, and a color proof corresponding to the image data for electronic plate-making is produced when the exposed sheet-shaped silver halide photographic light-sensitive paper is developed.
(Structure 6) An image forming apparatus having therein a cylinder which has an outer circumferential surface that is substantially a shape of columnar surface for holding fixedly a recording paper, a cylinder rotating means to rotate the cylinder with a column axis of the columnar surface serving substantially as a center, and an exposure head which exposes the recording paper by irradiating it with recording light, and forming an image on an image recording surface of the recording paper held fixedly on the cylinder by irradiating the recording light from the exposure head, wherein a cover which covers surroundings of the cylinder and is provided with a recording light emergent opening and a material ejecting opening is provided, and a clearance in the specific direction between the cover and the cylinder is made to be broader to form a shelter for the jammed recording paper.
In the invention of Structure 6, a clearance in the specific direction between the cover and the cylinder is made to be broader, and thereby, the recording paper which has come off the cylinder due to the high speed rotation, for example, can stay there, thus, even when the recording paper comes off the cylinder, a user can remove it easily and safely, and productivity of the recording apparatus can be improved.
(Structure 7) An image forming apparatus for conveying a recording paper loaded in a recording paper loading section to an image forming section, and thereby for forming an image, wherein there are provided a conveying means which conveys a recording paper along a conveyance path from the recording paper loading section to the image forming section, a shielding means which covers a processing window section representing a part of the conveyance path opened and can be opened and closed, and a locking means which prohibits an operation to open the shielding means while the conveyance means is operating.
In this image forming apparatus, prohibition for opening of the shielding means is released after the operation of the conveyance means is completely stopped, and therefore, when the recording paper needs to be removed, it can be removed easily, thus, it is possible to enhance safety and to prevent damage on movable mechanism of the image forming apparatus.
In the invention, an color proof image corresponding to color separated halftone original image data is a color proof image with which the printed matter produced from the color separated halftone original image data is simulated. Further, image data corresponding to color separated halftone original image data have only to be image data corresponding to color separated halftone original image data, and in addition to color separated halftone original im
Doi Masato
Fujita Katsushi
Kubota Takao
Tamakoshi Yasuaki
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Konica Corporation
Rutledge D.
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