EP0370475A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Original document detecting device for detecting a size of an original document
Assignee: Sharp Corp
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Filing: 1989-11-21
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Granted: —
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Expires: 2009-11-21
Abstract
Abstract An original document detecting device comprises a plurality of pairs of light emitting elements (7 to 10) and light receiving element (3 to 6) oppositely arranged on both sides of an original placing platform (2) on which an original document (24) is placed. When no original document is placed on the original placing platform (2), the light receiving element (3 to 6) receives the light from the light emitting element (7 to 10). When an original document is placed on the platform (2), the light is interrupted by the original document (24). Detecting means (11 to 14) is provided for detecting whether the light is received by the light receiving element or the light is interrupted by an original document, thereby detecting the presence or absence of the original document in dependence on the output signals of the light receiving elements. And there are provided a sensor(15) for detecting the intensity of disturbance light and drive control means for controlling the intensity of the input value of the light emitting elements so as to control the intensity of the input light of the light receiving elements in dependence on the output signals of the sensor.
Inventors
- 👤 Toshihisa 24-207 Minamidaiku-Cho Matsuo
- 👤 Toshio Yamagishi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:44
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/60; G03G15/607; G03B; G03B27/00; G03B27/32; G03B27/52; G03B27/62; G03B27/6207; G03B27/625; G03G2215/00; G03G2215/00172; G03G2215/00177; G03G2215/00181; G03G2215/00185
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
152 words
An original document detecting device for detecting whether an original document is present or absent, comprising: at least one pair of a light emitting element (7 to 10) and a light receiving element (3 to 6) oppositely disposed each other on both sides of an original placing platform (2) for placing an original document (24) thereon, detecting means (11 to 14) for detecting whether the light beam emitted from said light emitting element is received by said light receiving element or interrupted by an original document, thereby detecting the presence or absence of the original document in dependence on the output value of said light receiving element, sensor means (15) for detecting a quantity of disturbance light around the detecting device, control means (15 to 21) for controlling the quantity of the light beam to be emitted from said light emitting element in dependence on the output value of said sensor means.
Claim 2
Dependent Claim
152 words
An original document detecting device for detecting whether an original document is present or absent, comprising: at least one pair of a light emitting element (7 to 10) and a light receiving element (3 to 6) oppositely disposed each other on both sides of an original placing platform (2) for placing an original document (24) thereon, detecting means (11 to 14) for detecting whether the light beam emitted from said light emitting element is received by said light receiving element or interrupted by an original document, thereby detecting the presence or absence of the original document in dependence on the output value of said light receiving element, sensor means (15) for detecting a quantity of disturbance light around the detecting device, control means (15 to 21) for controlling the quantity of the light beam to be emitted from said light emitting element in dependence on the output value of said sensor means.
Claim 3
Dependent Claim
33 words
The original document detecting device according to claim 1, wherein a plurality of pairs of the light emitting element and light receiving element are disposed on both sides of the original placing platform.
Claim 4
Dependent Claim
30 words
The original document detecting device according to claim 1, wherein said light emitting element is made of infrared emitting diode and said light receiving element is made of photo diode.
Claim 5
Dependent Claim
20 words
The original document detecting device according to claim 1, wherein said sensor means is made of light receiving photo diode.
Claim 6
Dependent Claim
38 words
The original document detecting device according to claim 1, wherein said sensor means has its anode terminal connected to the earth through an output resistor and has its cathode terminal connected to a power source of +5 volts.
Claim 7
Dependent Claim
131 words
An original document detecting device for detecting whether an original document is present or absent, comprising: at least one pair of a light emitting element and a light receiving element oppositely disposed each other on both sides of an original placing platform for placing an original document thereon, detecting means for detecting whether the light beam emitted from said light emitting element is received by said light receiving element or interrupted by an original document, thereby detecting the presence or absence of the original document in dependence on the output value of said light receiving element, control means for controlling the quantity of the light beam to be emitted from said light emitting element so that the output value of said light receiving element is set to be a predetermined value.
Claim 8
Dependent Claim
131 words
An original document detecting device for detecting whether an original document is present or absent, comprising: at least one pair of a light emitting element and a light receiving element oppositely disposed each other on both sides of an original placing platform for placing an original document thereon, detecting means for detecting whether the light beam emitted from said light emitting element is received by said light receiving element or interrupted by an original document, thereby detecting the presence or absence of the original document in dependence on the output value of said light receiving element, control means for controlling the quantity of the light beam to be emitted from said light emitting element so that the output value of said light receiving element is set to be a predetermined value.
Claim 9
Dependent Claim
33 words
The original document detecting device according to claim 6, wherein a plurality of pairs of the light emitting element and light receiving element are disposed on both sides of the original placing platform.
Claim 10
Dependent Claim
30 words
The original document detecting device according to claim 6, wherein said light emitting element is made of infrared emitting diode and said light receiving element is made of photo diode.
Claim 11
Dependent Claim
38 words
The original document detecting device according to claim 8, wherein said light receiving diode has its anode terminal connected to the earth through a resistor and has its cathode terminal connected to a power source of +5 volts.
References Cited (Backward Citations)
No citation records indexed.
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