Edge-detecting device and image-forming device provided with the same
First Claim
1. An edge-detecting device for detecting an edge of a medium, the device comprising:
- a detecting unit that defines a target detection area, and that detects medium detection data at the target detection area, the medium detection data having a different value depending on whether or not a medium is present in the target detection area;
an adjusting unit that performs an adjusting operation by controlling the detecting unit to detect values of the medium detection data at a plurality of locations on the medium, thereby adjusting a determining condition based on the plurality of detected values; and
an edge detecting unit that performs an edge detecting operation by controlling the detecting unit to detect a value of the medium detection data while moving the position of the target detection area in relation to the medium and by determining whether or not the medium is present in the target detection area based on the value detected by the detecting unit and by using the adjusted determining condition, thereby detecting an edge position of the medium;
wherein the detecting unit includes a reflection-type sensor having a light-emitting element and a light-receiving element, the light-receiving element receiving light reflected from the target detection area when the light-emitting element emits light, the light-receiving element outputting data indicative of an amount of light received by the light-receiving element as the medium detection data;
wherein the edge detecting unit determines whether the medium is present in the target detection area based on whether the amount of light received by the light-receiving element exceeds a threshold value; and
wherein the adjusting unit includes a light-emitting adjusting unit that adjusts the amount of light emitted by the light-emitting element at the plurality of locations to such a value that causes the light-receiving element to receive light with an amount of a predetermined value.
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Accused Products
Abstract
An image-forming device includes a media sensor having a light-emitting element and a light-receiving element for detecting edge positions of a paper based on values outputted from the light-receiving element as the target detection area of the media sensor is moved in relation to the paper. The value of a current to be supplied to the light-emitting element for edge detection is determined in the following manner. First, the media sensor is moved to the center of the paper-conveying path (S110). Then, the paper is conveyed to a prescribed position (S120-S150). Next, the value of the current that should be supplied to the light-emitting element (light amount adjusting value) in order that output from the light-receiving element will reach a desired value is determined at a position A on the paper at which the target detection area of the media sensor is being presently located (S160, S170). The target detection area is subsequently moved to a position B and a position C, while repeating the process to determine the light amount adjusting value (S180-S230). Finally, the paper edge detecting current is set to the smallest of the light amount adjusting values determined at positions A-C (S240).
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Citations
16 Claims
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1. An edge-detecting device for detecting an edge of a medium, the device comprising:
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a detecting unit that defines a target detection area, and that detects medium detection data at the target detection area, the medium detection data having a different value depending on whether or not a medium is present in the target detection area;
an adjusting unit that performs an adjusting operation by controlling the detecting unit to detect values of the medium detection data at a plurality of locations on the medium, thereby adjusting a determining condition based on the plurality of detected values; and
an edge detecting unit that performs an edge detecting operation by controlling the detecting unit to detect a value of the medium detection data while moving the position of the target detection area in relation to the medium and by determining whether or not the medium is present in the target detection area based on the value detected by the detecting unit and by using the adjusted determining condition, thereby detecting an edge position of the medium;
wherein the detecting unit includes a reflection-type sensor having a light-emitting element and a light-receiving element, the light-receiving element receiving light reflected from the target detection area when the light-emitting element emits light, the light-receiving element outputting data indicative of an amount of light received by the light-receiving element as the medium detection data;
wherein the edge detecting unit determines whether the medium is present in the target detection area based on whether the amount of light received by the light-receiving element exceeds a threshold value; and
wherein the adjusting unit includes a light-emitting adjusting unit that adjusts the amount of light emitted by the light-emitting element at the plurality of locations to such a value that causes the light-receiving element to receive light with an amount of a predetermined value. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. An image-forming device for forming images on a recording medium, the device comprising:
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a conveying unit that conveys the recording medium in a recording-medium conveying direction;
a recording unit that moves substantially orthogonal to the recording-medium conveying direction and that performs a recording operation to form images on the recording medium; and
an edge-detecting device that detects an edge of a medium, the edge-detecting device including;
a detecting unit that defines a target detection area and that detects medium detection data at the target detection area, the medium detection data having a different value depending on whether or not a medium is present in the target detection area;
an adjusting unit that performs an adjusting operation by controlling the detecting unit to detect values of the medium detection data at a plurality of locations on the medium, thereby adjusting a determining condition based on the plurality of detected values; and
an edge detecting unit that performs an edge detecting operation by controlling the detecting unit to detect a value of the medium detection data while moving the position of the target detection area in relation to the medium and by determining whether or not the medium is present in the target detection area based on the value detected by the detecting unit and by using the adjusted determining condition, thereby detecting an edge position of the medium, the edge detecting unit detecting both side edge positions of the recording medium that is conveyed by the conveying unit, the recording unit performing the recording operation between both side edge positions of the recording medium detected by the edge detecting units;
wherein the detecting unit includes a reflection-type sensor having a light-emitting element and a light-receiving element, the light-receiving element receiving light reflected from the target detection area when the light-emitting element emits light, the light-receiving element outputting data indicative of an amount of light received by the light-receiving element as the medium detection data;
wherein the edge detecting unit determines whether the medium is present in the target detection area based on whether the amount of light received by the light-receiving element exceeds a threshold value;
wherein the adjusting unit includes a light-emitting adjusting unit that adjusts the amount of light emitted by the light-emitting element at the plurality of locations to such a value that causes the light-receiving element to receive light with an amount of a predetermined value;
wherein the adjusting unit includes a threshold adjusting unit that adjusts, as the determining condition, the amount of the threshold value to a value that corresponds to the predetermined value; and
wherein the light-emitting adjusting unit adjusts, as the determining condition, the amount of light emitted by the light-emitting element during the edge detecting operation based on the amounts of light that have been emitted by the light-emitting element at the plurality of locations on the medium. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
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Specification