US5045683A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light absorption detector with light emitting and light receiving elements
Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1990-01-16
•
Granted: 1991-09-03
•
Expires: 2010-01-16
Abstract
Abstract A light absorption detector has one or two light emitting members and a light receiving element spaced a predetermined distance apart from each other on a film substrate (1). Light is transmitted from one side to the other side of a subject. a change in the absorption magnitude of this transmitted light by the subject is then detected to provide respective information. A photodiode (PD) is located near the light emitting member or near two light emitting diodes (LED1, LED2). The photodiode detects a change in the quantity of light emitted. A CPU (16) corrects a change in the quantity of light with a change in the temperature of the light emitting element for controlling the current flowing to the light emitting member or light emitting diodes. Futher, a thermistor (37) and a heater (39) are located in the vicinity of at least one of a light emitting diode (34) and a photodiode (31). A CPU (43) controls a current flowing through the heater in response to a detection of an output of the thermistor so that the temperature of at least of the light emitting member or of the light receiving element is maintained constant.
Inventors
- 👤 Masahiko Kanda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:32
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/28; G01J3/42; A; A61; A61B; A61B5/00; A61B5/02; A61B5/024; A61B5/02416; G01J1/00; G01J1/10; G01J1/20; G01J1/28; G01J1/30; G01J1/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
242 words
A light absorption detector, comprising: a film substrate light emitting means (LED 1 , LED 2 ) secured on a flat surface of said film substrate for directing light to a subject; a first light receiving element spaced, on said film substrate, a predetermined distance apart from said light emitting means, for receiving light from said subject; a second light receiving element located near said light emitting means, for detecting a change in the quantity of light with a change in the temperature of said light emitting means; said second light receiving element being arranged together with said light emitting means on the same flat surface of said film substrate for directly receiving light from said light emitting means; control means (14, 15, 16) for controlling a current flowing through said light emitting element so as to correct the change in the quantity of light with the change in the temperature of said light emitting element in accordance with a power of received light of said second light receiving element; said detector further comprising a transparent semispherical resin cover (13) on said film substrate for covering said light emitting means and said second light receiving element, said second light receiving element being positioned for receiving a portion of light received from said light emitting means and reflected by a semi-spherical inner surface of said resin cover (13); and wherein said resin cover (13) comprises an evaporated silver film (131) on its surface.
Claim 2
Dependent Claim
242 words
A light absorption detector, comprising: a film substrate light emitting means (LED 1 , LED 2 ) secured on a flat surface of said film substrate for directing light to a subject; a first light receiving element spaced, on said film substrate, a predetermined distance apart from said light emitting means, for receiving light from said subject; a second light receiving element located near said light emitting means, for detecting a change in the quantity of light with a change in the temperature of said light emitting means; said second light receiving element being arranged together with said light emitting means on the same flat surface of said film substrate for directly receiving light from said light emitting means; control means (14, 15, 16) for controlling a current flowing through said light emitting element so as to correct the change in the quantity of light with the change in the temperature of said light emitting element in accordance with a power of received light of said second light receiving element; said detector further comprising a transparent semispherical resin cover (13) on said film substrate for covering said light emitting means and said second light receiving element, said second light receiving element being positioned for receiving a portion of light received from said light emitting means and reflected by a semi-spherical inner surface of said resin cover (13); and wherein said resin cover (13) comprises an evaporated silver film (131) on its surface.
Claim 3
Dependent Claim
37 words
The light absorption detector in accordance with claim 1, wherein said light emitting means comprise two LED chips (LED1, LED2) each located at an equal distance apart from said second light receiving element and at different positions.
Claim 4
Dependent Claim
96 words
The light absorption detector in accordance with claim 1, wherein said control means comprise a current-to-voltage converting circuit (14) for converting a current of said second light receiving element into a voltage; and A/D converting circuit (15) for converting the voltage converted by said current-to-voltage converting circuit into a digital signal; and a central processing circuit (16) responsive to the digital signal converted by said A/D converting circuit for determining whether an output voltage of said second light receiving element is lower than a predetermined voltage for controlling a current flowing through said light emitting means.
Claim 5
Dependent Claim
24 words
The light absorption detector of claim 1, wherein said light emitting means comprise at least two light emitting diode chips having different temperature characteristics.
Claim 6
Dependent Claim
139 words
A light absorption detector, comprising: a film substrate; a light emitting means (34) located on one major surface of said film substrate for directing light through a subject; a light receiving element (31) spaced, on said one major surface of said film substrate, a predetermined distance apart from said light emitting means, for receiving light transmitted through said subject; heating means (39) located on the other main surface of said film substrate substantially opposite said light emitting means; temperature detecting means (37) arranged in the vicinity of at least one of said light emitting means and said light receiving element; and control means (43) for making said heating means heat the vicinity of at least one of said light emitting element and said light receiving element so as to keep a temperature detected by said temperature detecting means constant.
Claim 7
Dependent Claim
139 words
A light absorption detector, comprising: a film substrate; a light emitting means (34) located on one major surface of said film substrate for directing light through a subject; a light receiving element (31) spaced, on said one major surface of said film substrate, a predetermined distance apart from said light emitting means, for receiving light transmitted through said subject; heating means (39) located on the other main surface of said film substrate substantially opposite said light emitting means; temperature detecting means (37) arranged in the vicinity of at least one of said light emitting means and said light receiving element; and control means (43) for making said heating means heat the vicinity of at least one of said light emitting element and said light receiving element so as to keep a temperature detected by said temperature detecting means constant.
Claim 8
Dependent Claim
31 words
The light absorption detector in accordance with claim 5, wherein said light emitting means comprises a heat sink (341), and wherein said temperature detecting means is located in said heat sink.
Claim 9
Dependent Claim
139 words
A light absorption detector, comprising: a film substrate; a light emitting means (34) located on one major surface of said film substrate for directing light through a subject; a light receiving element (31) spaced, on said one major surface of said film substrate, a predetermined distance apart from said light emitting means, for receiving light transmitted through said subject; heating means (39) located on the other main surface of said film substrate substantially opposite said light receiving element; temperature detecting means (37) arranged in the vicinity of at least one of said light emitting means and said light receiving element; and control means (43) for making said heating means heat the vicinity of at least one of said light emitting element and said light receiving element so as to keep a temperature detected by said temperature detecting means constant.
Claim 10
Dependent Claim
139 words
A light absorption detector, comprising: a film substrate; a light emitting means (34) located on one major surface of said film substrate for directing light through a subject; a light receiving element (31) spaced, on said one major surface of said film substrate, a predetermined distance apart from said light emitting means, for receiving light transmitted through said subject; heating means (39) located on the other main surface of said film substrate substantially opposite said light receiving element; temperature detecting means (37) arranged in the vicinity of at least one of said light emitting means and said light receiving element; and control means (43) for making said heating means heat the vicinity of at least one of said light emitting element and said light receiving element so as to keep a temperature detected by said temperature detecting means constant.
References Cited (Backward Citations)
US4182977A
Cited
FR2487010A1
Cited
US4431947A
Cited
US4695714A
Cited
EP0127947B1
Cited
JPS60158803A
Cited
US4701607A
Cited
EP0247777A1
Cited
US4724314A
Cited
US4837428A
Cited
US4917031A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-02 | 1995-03-04 | 1995-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-02 | 1999-03-04 | 1999-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-02 | 2003-03-04 | 2003-09-03 | $7700.00 | Window Closed / Lapsed |