US5495096A
Expired / Lapsed
US
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Multi-focus optical device
Assignee: Omron Corp
•
Filing: 1992-09-21
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Granted: 1996-02-27
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Expires: 2012-09-21
Abstract
Abstract A multi-focus optical sensing device for use in bar code scanners, photoelectric sensors and the like is disclosed. To extend the range of detection along the optical axis, without increasing the detection time, the focal point of the light beam is caused to move along the optical axis. A control and modulation circuit varies a current I f which drives an optical semiconductor serving as a light source. This changes the focal distance of a refraction lattice and so causes the focal position of the light beam emitted by light source to scan along the optical axis. This scan is repeated each time a polygonal mirror scans the light beam over the narrowest width 1/n (where n is an integer) of the bar code lines. A processing unit samples and processes the signal from a photodetector unit while the light beam is being scanned along the optical axis.
Inventors
- 👤 Shiro Ogata
- 👤 Hiroshi Goto
- 👤 Yoshinori Ito
- 👤 Koichi Imanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:41
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10792; G06K7/10801; G06K7/10811; G06K2207/00; G06K2207/1013
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
111 words
An optical sensor device to sense an object comprising: an optical semiconductor light source driven by input current; a diffractive condenser lens to diffract light emitted by said optical semiconductor light source, said lens comprising an unevenly spaced diffraction lattice, said lens directing light toward said object at a different focal length for each wavelength of said light emitted by said optical semiconductor light source; a photodetector unit to receive said light from said object; a processing unit to process signals from said photodetector unit; a drive circuit to vary said input current driving said optical semiconductor light source to thereby vary said wavelength emitted by said optical semiconductor light source.
Claim 2
Dependent Claim
111 words
An optical sensor device to sense an object comprising: an optical semiconductor light source driven by input current; a diffractive condenser lens to diffract light emitted by said optical semiconductor light source, said lens comprising an unevenly spaced diffraction lattice, said lens directing light toward said object at a different focal length for each wavelength of said light emitted by said optical semiconductor light source; a photodetector unit to receive said light from said object; a processing unit to process signals from said photodetector unit; a drive circuit to vary said input current driving said optical semiconductor light source to thereby vary said wavelength emitted by said optical semiconductor light source.
Claim 3
Dependent Claim
21 words
The optical sensor device recited in claim 1, wherein each cross section of said lens is in the form of sawteeth.
Claim 4
Dependent Claim
19 words
The optical sensor device recited in claim 1, wherein said input current is a pulsed current of varying amplitude.
Claim 5
Dependent Claim
29 words
The optical sensor device recited in claim 3, wherein a duty factor of said input current can vary to change the light output of said optical semiconductor light source.
Claim 6
Dependent Claim
29 words
The optical sensor device recited in claim 3, wherein a bias level of said input current can vary to change the light output of said optical semiconductor light source.
Claim 7
Dependent Claim
14 words
An optical sensor device recited in claim 1, wherein said input current is cyclic.
Claim 8
Dependent Claim
19 words
The optical sensor device recited in claim 6 comprising a manual control to vary the cycle of said input.
Claim 9
Dependent Claim
14 words
The optical sensor device recited in claim 6, wherein said input current varies continuously.
Claim 10
Dependent Claim
14 words
The optical sensor device recited in claim 6, wherein said input current varies discontinuously.
Claim 11
Dependent Claim
14 words
The optical sensor device recited in claim 1, wherein said input current varies continuously.
Claim 12
Dependent Claim
14 words
The optical sensor device recited in claim 1, wherein said input current varies discontinuously.
Claim 13
Dependent Claim
28 words
The optical sensor device recited in claim 1, wherein said processing unit processes said light by sampling an output from said photodetector unit and generating corresponding pulse signals.
Claim 14
Dependent Claim
30 words
An optical sensor device recited in claim 1, further comprising a feedback circuit to feed back a part of said light emitted by said optical semiconductor to said drive circuit.
Claim 15
Dependent Claim
91 words
An optical scanning sensor device comprising: an optical semiconductor light source having an output wavelength dependent upon a drive current; a diffractive condenser lens to diffract light emitted by said optical semiconductor light source, said lens comprising an unevenly spaced diffraction lattice, said lens directing light toward said object; a photodetector unit to receive said light from said object; a processing unit to process signals from said photodetector unit; a drive circuit to vary said drive current; and a scanning unit to scan said light diffracted by said refractive condenser lens.
Claim 16
Dependent Claim
91 words
An optical scanning sensor device comprising: an optical semiconductor light source having an output wavelength dependent upon a drive current; a diffractive condenser lens to diffract light emitted by said optical semiconductor light source, said lens comprising an unevenly spaced diffraction lattice, said lens directing light toward said object; a photodetector unit to receive said light from said object; a processing unit to process signals from said photodetector unit; a drive circuit to vary said drive current; and a scanning unit to scan said light diffracted by said refractive condenser lens.
Claim 17
Dependent Claim
19 words
The optical scanning sensor device recited in claim 14, wherein said object to be read comprises a bar code.
Claim 18
Dependent Claim
21 words
The optical scanning sensor device recited in claim 14, wherein each cross section of said lens has a form of sawteeth.
Claim 19
Dependent Claim
25 words
The optical scanning sensor device recited in claim 14, wherein said drive circuit varies said drive current for a period longer than one scanning time.
Claim 20
Dependent Claim
19 words
The optical scanning sensor device recited in claim 17 wherein said drive current is cyclic, said cycle being variable.
Claim 21
Dependent Claim
20 words
The optical scanning sensor device recited in claim 18 wherein said variable cycle can be set by a manual control.
Claim 22
Dependent Claim
20 words
The optical scanning sensor device recited in claim 14, wherein said drive current is a pulsed current of varying amplitude.
Claim 23
Dependent Claim
30 words
The optical scanning sensor device recited in claim 20, wherein a duty factor of said drive current can vary to change the light output of said optical semiconductor light source.
Claim 24
Dependent Claim
30 words
The optical scanning sensor device recited in claim 20, wherein a bias level of said drive current can vary to change the light output of said optical semiconductor light source.
Claim 25
Dependent Claim
44 words
The optical sensor device recited in claim 20, wherein a duty factor of said drive current can vary to change the light output of said optical semiconductor light source for a period shorter than a scanning time for a smallest segment of said object.
Claim 26
Dependent Claim
45 words
The optical scanning sensor device recited in claim 20, wherein a bias level of said drive current can vary to change the light output of said optical semiconductor light source for a period shorter than a scanning time for a smallest segment of said object.
Claim 27
Dependent Claim
32 words
The optical scanning sensor device recited in claim 14, wherein said drive circuit varies said drive current for a period shorter than a scanning time for a smallest segment of said object.
Claim 28
Dependent Claim
29 words
The optical scanning sensor device recited in claim 25 wherein said processing unit processes said light by sampling an output from said photodetector unit and generating corresponding pulse signals.
Claim 29
Dependent Claim
31 words
The optical scanning sensor device recited in claim 14, further comprising a feedback circuit to feed back a part of said light emitted by said optical semiconductor to said drive circuit.
Claim 30
Dependent Claim
93 words
An optical sensor device comprising: a light source having an adjustable output responsive to a control circuit, said control circuit adjusting the wavelength of light energy emitted by said light source; a lens receiving said light energy emitted by said light source, said lens having an output directing received light energy toward an object to be sensed and having a significantly different focal length received thereby providing a different resolution of detection at each said wavelength received by said lens; and a detector for receiving light energy from said object to be sensed.
Claim 31
Dependent Claim
93 words
An optical sensor device comprising: a light source having an adjustable output responsive to a control circuit, said control circuit adjusting the wavelength of light energy emitted by said light source; a lens receiving said light energy emitted by said light source, said lens having an output directing received light energy toward an object to be sensed and having a significantly different focal length received thereby providing a different resolution of detection at each said wavelength received by said lens; and a detector for receiving light energy from said object to be sensed.
Claim 32
Dependent Claim
48 words
The apparatus recited in claim 28 wherein said control circuit comprises means for driving said light source to produce a plurality of wavelengths during a sensing time period for sensing a said object, said plurality of wavelengths resulting in a plurality of focal lengths during said sensing time.
Claim 33
Dependent Claim
24 words
The apparatus recited in claim 29 wherein said means for driving comprises a variable current source to adjust said output of said light source.
Claim 34
Dependent Claim
44 words
The apparatus recited in claim 29 wherein said means for driving produces a plurality of wavelengths resulting in a plurality of focal lengths within a reading distance from said object to said apparatus, each said focal length providing a different resolution of said detector.
Claim 35
Dependent Claim
31 words
The apparatus recited in claim 29 further comprising a scanning unit, said scanning unit scanning light energy from said lens over at least a portion of said object to be sensed.
Claim 36
Dependent Claim
49 words
The apparatus recited in claim 32, wherein said portion of said object to be sensed comprises a plurality of segments and wherein said means for driving produces a plurality of wavelengths, resulting in a plurality of focal lengths, for a said sensing time period of a smallest said segment.
Claim 37
Dependent Claim
28 words
The apparatus recited in claim 32, wherein said portion of said object comprises a bar code and wherein lines and spaces of said bar code comprise said segments.
Claim 38
Dependent Claim
55 words
The apparatus recited in claim 28, further comprising an element receiving light from said light source, said element producing a signal indicative of said output from said light source, said signal being fed back to said control circuit and being used by said control circuit to adjust said light source output to a predetermined level.
Claim 39
Independent Claim
57 words
A method of optically sensing an object, said method comprising the steps of: directing a wavelength adjustable light source to a lens, said lens having significantly different focal length for each wavelength emitted from said light source; directing light from said lens toward an object; adjusting the wavelength emitted to change the focal length; and detecting light.
Claim 40
Independent Claim
57 words
A method of optically sensing an object, said method comprising the steps of: directing a wavelength adjustable light source to a lens, said lens having significantly different focal length for each wavelength emitted from said light source; directing light from said lens toward an object; adjusting the wavelength emitted to change the focal length; and detecting light.
Claim 41
Dependent Claim
25 words
The method recited in claim 36, further comprising scanning light energy from said lens over at least a portion of said object to be sensed.
Claim 42
Dependent Claim
41 words
The method recited in claim 37, comprising scanning a plurality of segments of said object and adjusting the wavelength from said light source to produce a plurality of focal lengths for a sensing time period for a smallest of said segments.
Claim 43
Dependent Claim
23 words
The method recited in claim 36, wherein said step of adjusting the wavelength varies the focal lengths of light emitted from said lens.
Claim 44
Dependent Claim
40 words
The method recited in claim 39, wherein the step of detecting light from said object to be sensed comprises detecting light when said light from said lens has a focal length in a range over which said focal length varies.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-02-26 | 1999-08-28 | 2000-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-02-26 | 2003-08-28 | 2004-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-02-26 | 2007-08-28 | 2008-02-27 | $7700.00 | Window Closed / Lapsed |