Photography – Fluid-treating apparatus – Photographic medium or cartridge sensing
Reexamination Certificate
1999-03-30
2001-02-27
Rutledge, D. (Department: 2851)
Photography
Fluid-treating apparatus
Photographic medium or cartridge sensing
C396S568000, C355S040000
Reexamination Certificate
active
06193423
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for monitoring a sheet material in a conveying apparatus which is used in the field of photographic technology and which conveys sheet materials such as heat-sensitive materials and photosensitive materials e.g., photographic films and photographic paper, along a prescribed conveying path, and to a method for monitoring a sheet material by using the device.
2. Description of the Related Art
Conventionally, when sheet materials, for example, photosensitive materials such as photographic films, are conveyed along a prescribed conveying path, a combination of an infrared LED and a phototransistor (hereinafter, this combination is referred to as a “photosensor”) is provided for each film size (film width), such that respective photosensors are disposed at positions corresponding to the edges of films of the various film sizes. The size of the film being conveyed is recognized by the detection of the film edge by the photosensor.
The film size can be recognized by using this method. However, when a film meanders, the phototransistor disposed at a position next to the “correct” position may detect the edge of the film such that a size different from the correct size is recognized.
The above problem occurs because the photosensors are not continuously arranged but are disposed at discrete positions along the edge-line of films. An increased number of phototransistors may be disposed without gaps therebetween to overcome this problem.
However, even when an increased number of phototransistors are disposed without gaps therebetween, the detection points which are detected by the phototransistors still remain as discrete points due to restrictions imposed by the shape of the phototransistor. Therefore, errors in recognition of film size cannot be eliminated completely.
SUMMARY OF THE INVENTION
In view of the aforementioned problems, an object of the present invention is to provide a device for monitoring a sheet material which can reliably recognize the position of an edge of a sheet material moving along a conveying path, and to provide a method of a monitoring a sheet material by using the device.
A first aspect of the present invention provides a device for monitoring a sheet material which device is used for a conveying apparatus for conveying sheet materials along a prescribed conveying path, said device comprising: a photoelectric conversion element which has a linear detecting area and outputs values which vary in accordance with an amount of light received at the detecting area, the amount of light changing due to the passage of a sheet material along the conveying path; and recognizing means which recognizes a position of a transverse direction end portion of the sheet material on the basis of a value output by the photoelectric conversion element.
In the first aspect of the present invention, a photoelectric conversion element which outputs a value which changes in accordance with the amount of light received at a linear detecting area is used. For example, the photoelectric conversion element is disposed along transverse direction of the sheet material. It is preferable that the light source and the photoelectric conversion element are disposed at opposite sides of the conveying path of the sheet material so that a prescribed amount of light is irradiated on to the entire detecting area of the photoelectric conversion element through the conveying path of the sheet material (a transmission-type arrangement). Alternatively, the light source and the photoelectric conversion element may be disposed at the same side of the conveying path of the sheet material (a reflection-type arrangement). In a preferable embodiment of the present invention, the transmission-type arrangement is used.
When the photoelectric conversion element and the light source are disposed in the transmission-type arrangement, a sheet material conveyed along the conveying path blocks a portion of the photoelectric conversion element. Therefore, when an edge of the sheet material moves, i.e., when the edge of the sheet material moves in the transverse direction, the output value changes, and the amount of the movement of the edge can be detected on the basis of the change in the output value.
When a plurality of sheet materials having different widths are conveyed along the same conveying path, the output value obtained during passage of a sheet material differs in accordance with the width of the sheet material. Therefore, it can be reliably recognized that a plurality of sheet materials having different widths are being conveyed along the route.
In the second aspect of the present invention, the width of the sheet material in a transverse direction and the type of the sheet material are recognized on the basis of the position of the transverse direction end portion of the sheet material which is recognized in the first aspect.
The position of the transverse direction end portion varies even when a single type of sheet material is conveyed. However, when a plurality of sheet materials having different widths are conveyed, the characteristic of the output value varies in accordance with the widths of the sheet materials.
Therefore, when a map showing relationships between output values and the widths of sheet materials is prepared in advance, the width and the type of a sheet material which is currently being conveyed can be automatically recognized.
In the third aspect of the present invention, the change in the amount of light received at the detecting area due to the passage of the sheet material along the conveying path is caused by the presence or absence, the number and the pitch of perforations formed in the sheet material, and the type of the sheet material is recognized from the presence or absence, the number and the pitch of the perforations.
Therefore, in accordance with the third aspect of the invention, the type of the sheet material which is currently being conveyed can be automatically recognized when a map showing relationships between output values and the presence or absence, the number and the pitch of perforations of sheet materials is prepared in advance.
In the fourth aspect of the present invention, the amount of meandering of the sheet material conveyed along the conveying path is recognized on the basis of the position of the transverse direction end portion of the sheet material.
In accordance with the fourth aspect of the invention, for example, when, on the basis of the position of the transverse direction end portion of the sheet material currently being conveyed on the conveying path, the current position of the end portion is found to be different from a reference position which is determined in advance, it can be recognized that the sheet material is meandering and that jamming may possibly occur. Thus, notification can be given quickly that the sheet material is meandering, or the conveying of the sheet material can be quickly stopped and automatically. Thus, deformation and breakage of the sheet material can be prevented.
In the fifth aspect of the present invention, the photoelectric conversion element is a position sensitive detector (PSD) which has a unidimensionally continuous detecting area formed by one half portion and another half portion which are separated at a central position of the PSD which is a reference position, and each half portion outputs an electric signal which corresponds to an amount of light received thereby.
In the fifth aspect of the invention, a plurality of sheet materials having different widths are conveyed along the conveying path in a manner such that the central line of each sheet material is disposed at the same position, and one end of the detecting area of the PSD is disposed at a position coinciding with the central lines of the sheet materials.
In this way, sheet materials having different widths can be discriminated from each other by the output values from the both ends of the PSD.
When the sheet materials are photographic films, even if th
Fuji Photo Film Co. , Ltd.
Rutledge D.
Sughrue Mion Zinn Macpeak & Seas, PLLC
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