Patent US4851924A successfully refreshed from Google Patents.
US4851924A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color recorder overhead projector with color recorder
Assignee: Ricoh Co Ltd
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Filing: 1988-07-18
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Granted: 1989-07-25
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Expires: 2008-07-18
Abstract
Abstract An overhead projector having scanning device for scanning an original image thereby generating electric signals corresponding to the original image, selecting device for selecting one of a thermochromic film and a thermographic paper, a first heating device for heating the film thereby erasing an image formed formerly in the film, a second heating device for heating the film in accordance with the electric signals transmitted from the scanning device to form an image corresponding to the original image in the film when the film is selected by the selecting device and for jheating the thermographic paper in accordance with the electric signals transmitted from the scanning device to print an image corresponding to the original image in the thermographic paper when the thermographic paper is selected by the selecting device, and projecting device for projecting the image formed in the film on a given screen.
Inventors
- 👤 Takuma Nakamura
- 👤 Yasuhiko Saka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:22
CPC Classifications
H; H04; H04N; H04N1/00; H04N1/0035; B; B41; B41M; B41M5/00; B41M5/26; B41M5/28; B41M5/282; G; G03; G03B; G03B21/00; G03B21/132; Y; Y10; Y10S; Y10S353/00; Y10S353/03
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
231 words
An overhead projector comprising: scanning means for scanning an original image thereby generating electric signals corresponding to said original image; selecting means for selecting one of a film capable of being transparent on being heated to a first temperature, keeping transparent even after being cooled to normal room temperature, being opaque on being heated to a second temperature higher than said first temperature and keeping opaque even after being cooled to normal room temperature, and a thermographic paper capable of coloring on being heated to a third temperature; first heating means for heating said film to said first temperature thereby erasing an image formed formerly in said film; second heating means adapted to press said film with a first pressing force and heat said film to said second temperature in accordance with said electric signals transmitted from said scanning means to form an image corresponding to said original image in said film when said film is selected by said selecting means and adapted to press said thermographic paper with a second pressing force and heat said thermographic paper to said third temperature in accordance with said electric signals transmitted from said scanning means to print an image corresponding to said original image in said thermographic paper when said thermographic paper is selected by said selecting means; and projecting means for projecting said image formed in said film on a given screen.
Claim 2
Dependent Claim
231 words
An overhead projector comprising: scanning means for scanning an original image thereby generating electric signals corresponding to said original image; selecting means for selecting one of a film capable of being transparent on being heated to a first temperature, keeping transparent even after being cooled to normal room temperature, being opaque on being heated to a second temperature higher than said first temperature and keeping opaque even after being cooled to normal room temperature, and a thermographic paper capable of coloring on being heated to a third temperature; first heating means for heating said film to said first temperature thereby erasing an image formed formerly in said film; second heating means adapted to press said film with a first pressing force and heat said film to said second temperature in accordance with said electric signals transmitted from said scanning means to form an image corresponding to said original image in said film when said film is selected by said selecting means and adapted to press said thermographic paper with a second pressing force and heat said thermographic paper to said third temperature in accordance with said electric signals transmitted from said scanning means to print an image corresponding to said original image in said thermographic paper when said thermographic paper is selected by said selecting means; and projecting means for projecting said image formed in said film on a given screen.
Claim 3
Dependent Claim
28 words
An overhead projector according to claim 1, wherein said film comprises a film base of polyester and a thermochromic layer formed on one surface of said film base.
Claim 4
Dependent Claim
38 words
An overhead projector according to claim 1, wherein said first pressing force is in the range of 200 to 400 g/cm 2 and said second pressing force is in the range of 3 to 5 kg/cm 2 .
Claim 5
Dependent Claim
23 words
An overhead projector according to claim 1, wherein said first temperature is approximately 60° C. and said second temperature is approximately 72° C.
Claim 6
Dependent Claim
35 words
An overhead projector according to claim 1, wherein said second heating means is adapted to control temperature of a heating element thereof by changing a width of an electric pulse applied to the heating element.
Claim 7
Dependent Claim
189 words
An overhead projector comprising: scanning means for scanning an original image thereby generating electric signals corresponding to said original image; a film capable of being transparent on being heated to a first temperature, keeping transparent even after being cooled to normal room temperature, being opaque on being heated to a second temperature higher than said first temperature and keeping opaque even after being cooled to normal room temperature, said film being composed of a film base capable of retaining stiffness thereof up to said first temperature and a thermochromic layer formed on one surface of said film base; first heating means adapted to contact said film base of said film and heat said film to said first temperature so as to erase an image formerly formed in said film; second heating means adapted to contact said thermochromic layer of said film and heat said film to said second temperature in accordance with said electric signals transmitted from said scanning means in order to form an image corresponding to said original image in said film; and projecting means for projecting said image formed in said film on a given screen.
Claim 8
Dependent Claim
189 words
An overhead projector comprising: scanning means for scanning an original image thereby generating electric signals corresponding to said original image; a film capable of being transparent on being heated to a first temperature, keeping transparent even after being cooled to normal room temperature, being opaque on being heated to a second temperature higher than said first temperature and keeping opaque even after being cooled to normal room temperature, said film being composed of a film base capable of retaining stiffness thereof up to said first temperature and a thermochromic layer formed on one surface of said film base; first heating means adapted to contact said film base of said film and heat said film to said first temperature so as to erase an image formerly formed in said film; second heating means adapted to contact said thermochromic layer of said film and heat said film to said second temperature in accordance with said electric signals transmitted from said scanning means in order to form an image corresponding to said original image in said film; and projecting means for projecting said image formed in said film on a given screen.
Claim 9
Dependent Claim
26 words
An overhead projector according to claim 6, wherein said first heating means is provided with means for retaining tension of said film at a fixed magnitude.
Claim 10
Dependent Claim
34 words
An overhead projector according to claim 6, wherein said first heating means is so adapted that said film being heated to said first temperature and consequently softened is cooled naturally until said film stiffness.
Claim 11
Dependent Claim
23 words
An overhead projector according to claim 6, wherein said first temperature is approximately 60° C. and said second temperature is approximately 72° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-07-24 | 1993-01-23 | 1993-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-24 | 1997-01-23 | 1997-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-24 | 2001-01-23 | 2001-07-25 | $7700.00 | Window Closed / Lapsed |