US5629512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Invisible information recording medium and apparatus for reading information from the same
Assignee: Olympus Corp
•
Filing: 1995-05-19
•
Granted: 1997-05-13
•
Expires: 2015-05-19
Abstract
Abstract An invisible information recording medium includes an underlying layer, an invisible information recording layer provided above the underlying layer, being invisible under visible light, and fluorescing upon being applied with light having a particular wavelength excepting that of the visible light, thus becoming visible, and an optical modulation layer provided between the underlying layer and the recording layer. When the modulation layer includes a photochromic layer, an information reading apparatus for reading information from the medium includes a preliminary coloring unit for coloring the photochromic layer of the modulation layer in advance, and an information reading optical system for applying the light having the particular wavelength excepting that of the visible light to the recording layer to cause the recording layer to fluoresce after the photochromic layer is turned to the colored state by the coloring unit, thereby making the recording medium visible, and reading information from the recording layer which has become visible. When the optical modulation layer includes an optical polarizing film, an information reading apparatus for reading information from the medium includes an information reading optical system for reading information from the recording layer which has become visible, and an optical polarizing unit, interposed between the recording layer and the optical system and having an optical polarizing angle perpendicular to that of the polarizing film, for guiding light from the recording layer which has become visible to the optical system.
Inventors
- 👤 Yasunobu Haga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:15
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/12; G06K19/00; G06K19/06; G06K19/06009; G06K19/06046; G06K19/08; G06K19/083; Y; Y10; Y10S; Y10S430/00; Y10S430/163
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
182 words
An information reading apparatus for reading information from an invisible information recording medium including: an underlying layer; an invisible information recording layer which is provided above said underlying layer, is invisible under visible light, and fluoresces upon being applied with light having a particular wavelength excepting that of the visible light, thus becoming visible; and an optical modulation layer provided between said underlying layer and said invisible information recording layer and including a photochromic layer, said information reading apparatus comprising: preliminary coloring means for coloring said photochromic layer of said optical modulation layer of said invisible information recording medium in advance; and an information reading optical system for applying the light having the particular wavelength excepting that of the visible light to said invisible information recording layer of said invisible information recording medium to cause said invisible information recording layer to fluoresce immediately after said photochromic layer of said optical modulation layer is colored in advance by said preliminary coloring means, thereby making said invisible information recording medium visible, and reading information from said invisible information recording layer which has become visible.
Claim 2
Dependent Claim
182 words
An information reading apparatus for reading information from an invisible information recording medium including: an underlying layer; an invisible information recording layer which is provided above said underlying layer, is invisible under visible light, and fluoresces upon being applied with light having a particular wavelength excepting that of the visible light, thus becoming visible; and an optical modulation layer provided between said underlying layer and said invisible information recording layer and including a photochromic layer, said information reading apparatus comprising: preliminary coloring means for coloring said photochromic layer of said optical modulation layer of said invisible information recording medium in advance; and an information reading optical system for applying the light having the particular wavelength excepting that of the visible light to said invisible information recording layer of said invisible information recording medium to cause said invisible information recording layer to fluoresce immediately after said photochromic layer of said optical modulation layer is colored in advance by said preliminary coloring means, thereby making said invisible information recording medium visible, and reading information from said invisible information recording layer which has become visible.
Claim 3
Dependent Claim
49 words
An apparatus according to claim 1, further comprising means for turning said photochromic layer of said optical modulation layer of said invisible information recording medium to a non-colored state after information is read from said invisible information recording medium which has become visible, by said information reading optical system.
Claim 4
Dependent Claim
31 words
An apparatus according to claim 2, wherein said means for turning said photochromic layer to the non-colored state comprises visible light emitting means for emitting visible light to said photochromic layer.
Claim 5
Dependent Claim
26 words
An apparatus according to claim 2, wherein said means for turning said photochromic layer to the non-colored state comprises heating means for heating said photochromic layer.
Claim 6
Dependent Claim
168 words
An information reading apparatus for reading information from an invisible information recording medium including: an underlying layer, an invisible information recording layer which is provided above said underlying layer, is invisible under visible light, and fluoresces upon being applied with light having a particular wavelength excepting that of the visible light, thus becoming visible; and an optical modulation layer provided between said underlying layer and said invisible information recording layer and including an optical polarizing layer, said information reading apparatus comprising: an information reading optical system for reading information from said invisible information recording layer which has become visible; and optical polarizing means, interposed between said invisible information recording layer which has become visible and said information reading optical system and having an optical polarizing angle substantially perpendicular to the optical polarizing angle of said optical polarizing film of said optical modulation layer of said invisible information recording medium, for guiding light from said invisible information recording layer which has become visible to said information reading optical system.
Claim 7
Dependent Claim
168 words
An information reading apparatus for reading information from an invisible information recording medium including: an underlying layer, an invisible information recording layer which is provided above said underlying layer, is invisible under visible light, and fluoresces upon being applied with light having a particular wavelength excepting that of the visible light, thus becoming visible; and an optical modulation layer provided between said underlying layer and said invisible information recording layer and including an optical polarizing layer, said information reading apparatus comprising: an information reading optical system for reading information from said invisible information recording layer which has become visible; and optical polarizing means, interposed between said invisible information recording layer which has become visible and said information reading optical system and having an optical polarizing angle substantially perpendicular to the optical polarizing angle of said optical polarizing film of said optical modulation layer of said invisible information recording medium, for guiding light from said invisible information recording layer which has become visible to said information reading optical system.
References Cited (Backward Citations)
US3614430A
Cited
US3887271A
Cited
US4579754A
Cited
WO1987006197A1
Cited
US5380992A
Cited
JPH0375886A
Cited
JPH03182988A
Cited
US5414262A
Cited
JPH0512503A
Cited
JPH05149786A
Cited
US5502304A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-05-12 | 2000-11-11 | 2001-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-05-12 | 2004-11-11 | 2005-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-05-12 | 2008-11-11 | 2009-05-13 | $7700.00 | Window Closed / Lapsed |