Patent US4637150A successfully refreshed from Google Patents.
US4637150A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light box for providing a background illumination having brightness values locally adjusted to the density of a transparency to be viewed by means of the light box
Assignee: Optische Industrie de Oude Delft NV
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Filing: 1985-05-17
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Granted: 1987-01-20
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Expires: 2005-05-17
Abstract
Abstract A device for directly viewing an image on a film transparency, in which the illuminating light source is controlled on the basis of discrete information elements written into and stored in a two-dimensional memory during a preliminary image brightness scanning operation. At option, the light beam produced by the light source either has its intensity or its scanning velocity controlled, in order to accordingly vary the brightness level of elementary film surface regions. Velocity modulation is to be preferred as the beam brightness level can then be maintained at an optimally constant value, while the dynamic contrast range of the image viewed by the observer is substantially determined by the beam velocity modulation range.
Inventors
- 👤 Ronald J. Geluk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:48
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/02; G02B27/022; G02B27/024; G02B27/026
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
167 words
An assembly for viewing a tranparency, such as an X-ray photograph, which comprises: a screen for viewing said transparency, said transparency being positioned in front of said screen; a light source means for illuminating said screen, said light source means capable of forming a light beam on controlled location and intensity on said screen; means for controlling said light source means to illuminate said screen in accordance with a two-dimensional distribution of brightness level values adjusted to local density of said transparency; a photosensitive detection means for scanning said transparency for measuring local brightness level values representative of local light intensity levels of said transparency; random access memory means having memory locations corresponding to said two-dimensional distribution of brightness level values for storing in said memory location said brightness level values measured by said photosensitive detector means; and a control device for modulating intensity of said light beam of said light source means inversely proportional to said brightness level values read out from said random access memory.
Claim 2
Dependent Claim
167 words
An assembly for viewing a tranparency, such as an X-ray photograph, which comprises: a screen for viewing said transparency, said transparency being positioned in front of said screen; a light source means for illuminating said screen, said light source means capable of forming a light beam on controlled location and intensity on said screen; means for controlling said light source means to illuminate said screen in accordance with a two-dimensional distribution of brightness level values adjusted to local density of said transparency; a photosensitive detection means for scanning said transparency for measuring local brightness level values representative of local light intensity levels of said transparency; random access memory means having memory locations corresponding to said two-dimensional distribution of brightness level values for storing in said memory location said brightness level values measured by said photosensitive detector means; and a control device for modulating intensity of said light beam of said light source means inversely proportional to said brightness level values read out from said random access memory.
Claim 3
Dependent Claim
168 words
An assembly for viewing a transparency, such as an X-ray photograph, which comprises: a screen for viewing said transparency, said transparency being positioned in front of said screen; a light source means for illuminating said screen, said light source means capable of forming a light beam on controlled location and intensity on said screen; means for controlling said light source means to illuminate said screen in accordance with a two-dimensional distribution of brightness level values adjusted to local density of said transparency; a photosensitive detection means for scanning said transparency for measuring local brightness level values representative of local light intensity levels of said transparency; random access memory means having memory locations corresponding to said two-dimensional distribution of brightness level values for storing in said memory location said brightness level values measured by said photosensitive detector means; and a control device for modulating a velocity of movement of said light beam over said screen in proportion to said brightness level values read out from said random access memory.
Claim 4
Dependent Claim
168 words
An assembly for viewing a transparency, such as an X-ray photograph, which comprises: a screen for viewing said transparency, said transparency being positioned in front of said screen; a light source means for illuminating said screen, said light source means capable of forming a light beam on controlled location and intensity on said screen; means for controlling said light source means to illuminate said screen in accordance with a two-dimensional distribution of brightness level values adjusted to local density of said transparency; a photosensitive detection means for scanning said transparency for measuring local brightness level values representative of local light intensity levels of said transparency; random access memory means having memory locations corresponding to said two-dimensional distribution of brightness level values for storing in said memory location said brightness level values measured by said photosensitive detector means; and a control device for modulating a velocity of movement of said light beam over said screen in proportion to said brightness level values read out from said random access memory.
Claim 5
Dependent Claim
17 words
The assembly as defined in claim 1 wherein said photosensitive detector means is a rectilinear photosensitive strip.
Claim 6
Dependent Claim
17 words
The assembly as defined in claim 2 wherein said photosensitive detector means is a rectilinear photosensitive strip.
Claim 7
Dependent Claim
24 words
The assembly as defined in claim 1 wherein said photosensitive detector means includes a first and second photosensitive strip substantially parallel to each other.
Claim 8
Dependent Claim
24 words
The assembly as defined in claim 2 wherein said photosensitive detector means includes a first and second photosensitive strip substantially parallel to each other.
References Cited (Backward Citations)
US1803631A
Cited
US2516270A
Cited
FR1142655A
Cited
US3249691A
Cited
US3492486A
Cited
US4003151A
Cited
US4118654A
Cited
US4164822A
Cited
US4267489A
Cited
US4335421A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-19 | 1990-07-21 | 1991-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-19 | 1994-07-21 | 1995-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-19 | 1998-07-21 | 1999-01-20 | $7700.00 | Window Closed / Lapsed |