Photocopying – Projection printing and copying cameras – Illumination systems or details
Reexamination Certificate
2002-03-25
2004-01-06
Mathews, Alan A. (Department: 2851)
Photocopying
Projection printing and copying cameras
Illumination systems or details
C347S233000
Reexamination Certificate
active
06674515
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a light beam cut-off device which is applied to, for example, an image recording apparatus in which a light beam modulated by a light beam scanning device in accordance with image information is generated and a photosensitive material is exposed to the light beam to allow an image to be formed thereon, which light beam cut-off device cuts off the light beam at a position between the light beam scanning device and the photosensitive material at the time exposure for the photosensitive material is stopped.
2. Description of the Related Art
In recent years, a digital photographic printer (hereinafter referred to as “photographic printer”) utilizing digital exposure has been put to practical use. In the photographic printer, a light beam modulated in accordance with digital image data is deflected by a light beam scanning device in a main scanning direction, and at the same time, a photosensitive material being conveyed in a sub-scanning direction is exposed by scanning to the light beam to allow an image (latent image) to be formed thereon. Thereafter, the photosensitive material is conveyed to a developing section and subjected therein to developing processing, and outputted as a print (photograph). In some of such photographic printers, roll paper in which an elongated photosensitive material is wound in the form of a roll is used to carry out printing processing and developing processing for the photosensitive material continuously for a long time. In the photographic printer in which roll paper is used as the photosensitive material, roll paper pulled out from a magazine is subjected to various processing including exposure, developing and drying while being conveyed along a predetermined conveying path, and cut out for each frame by a cutter provided in the vicinity of an exit of the developing section and made into photographic prints. The light beam scanning device used by such a photographic printer may be provided with a light source such as a laser diode (LD) for outputting a light beam, a main scanning means which deflects a light beam outputted from the light source and effects main scanning by the light beam on a photosensitive material, and an external modulator for modulating the light beam outputted from the light source based on an image signal.
In the aforementioned photographic printer, so long as a plurality of image signals each bearing an image are sequentially supplied without placing a waiting time therebetween, images can be sequentially recorded without stopping conveying of a photosensitive material. However, there is a possibility that an image signal which bears an image to be subsequently recorded is not immediately supplied at the time recording of a certain image is completed. In this case, generally, conveying of the photosensitive material is temporarily stopped so that the photosensitive material may not be wastefully consumed. However, in a case in which a light beam is modulated by an external modulator, if the photosensitive material is brought into a stopped state, a region of the photosensitive material with an image recorded thereon, or its vicinities may be affected by fogging. In other words, when the external modulator is used, a recording light source is generally brought into a state of being continuously turned on, and the extinction ratio of a light modulator such as an acousto-optic modulator (AOM) is about 1:1000. The light beam emitted from the recording light source in a state of being continuously turned on cannot be completely cut off, and therefore, the photosensitive material stopped at a fixed position is irradiated with the light beam. Although the light beam is very weak, a fixed region on the photosensitive material is continuously irradiated with the light beam during the photosensitive material being stopped, thereby causing fogging on the photosensitive material. Such fogging of the photosensitive material occurs not only in a blank region but also in an image region in accordance with a method for controlling conveying of the photosensitive material. As a result, the quality of a printed photographic image is considerably deteriorated.
Some of conventional light beam scanning devices applied to an image recording apparatus such as a photographic printer may include therein a mechanical shutter mechanism for a light beam so as to prevent the aforementioned fogging of a photosensitive material. Such a light beam scanning device is disclosed in, for example, Japanese Patent Application (JP-A) No. 9-121269. However, the mechanical shutter mechanism unavoidably generates a vibration and the vibration is transmitted to a light source or a main scanning means, which results in deterioration of image quality. Accordingly, the light beam scanning device needs to have a vibration cut-off structure which prevents transmission of a vibration from the shutter mechanism. However, the vibration cut-off structure is disposed in a narrow inner space of the apparatus and the structure becomes complicated.
Further, in a photographic printer in which an image is formed on a photosensitive material (sheet paper) previously in the shape of a sheet, sheet paper can be held at the upstream side of an exposure position at the time exposure by the light beam scanning device is stopped. Therefore, no shutter mechanism for preventing occurrence of fogging needs to be provided in the light beam scanning device. However, the light beam scanning device having no built-in shutter mechanism is not directly applied to a photographic printer in which an image is formed on an elongated photosensitive material (roll paper), and needs to be modified on a large scale. For this reason, the light beam scanning device cannot be shared between the photographic printer for forming an image on sheet material and the photographic printer for forming an image on roll paper. As a result, reduction in costs of the device cannot be facilitated.
SUMMARY OF THE INVENTION
In view of the aforementioned circumstances, it is an object of the present invention to provide a light beam cut-off (blocking) device which can be installed separately from a light beam scanning device and which can cut off a light beam emitted from the light beam scanning device immediately before a photosensitive material at the time exposure for the photosensitive material is stopped, and can prevent transmission of a vibration to the light beam scanning device.
In accordance with a first aspect of the present invention, there is provided a light beam cut-off device which comprises: a shutter member disposed between a light beam scanning device which emits a light beam, and a photosensitive material exposed to a light beam emitted from the light beam scanning device, and supported in a movable manner between a cut-off position at which an optical path of the light beam emitted from the light beam scanning device is cut off by the shutter member, and an open position at which the shutter member retreats from the optical path of the light beam emitted from the light beam scanning device; a shutter driving portion for moving the shutter member to the open position at the time the photosensitive material is exposed by the light beam scanning device, and moving the shutter member to the cut-off position at the time exposure for the photosensitive material is stopped; a chassis member on which the shutter member and the shutter driving portion are mounted; and a vibration cut-off portion which prevents transmission of a vibration from the chassis member to the light beam scanning device.
In accordance with a second aspect of the present invention, in the device of the first aspect, the light beam scanning device and the chassis member are supported by a supporting structure, the vibration cut-off portion is disposed at least one of between the chassis member and the supporting structure and between the light beam scanning device and the supporting structure.
In accordance with a third aspect of the present invention
Fuji Photo Film Co, Ltd.
Mathews Alan A.
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