US4975808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Backlighting apparatus
Assignee: Motorola Solutions Inc
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Filing: 1989-10-02
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Granted: 1990-12-04
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Expires: 2009-10-02
Abstract
Abstract Improved backlighting apparatus evenly illuminates positive and negative LCDs under all ambient lighting conditions. Incandescent lamps (301-304) provide light for distribution by a light pipe (101). The bottom of the light pipe (101) is selectively painted white to reflect light to the top of the light pipe (101) while the unpainted areas reflect light internal to the light pipe (101), controlling hot and dim spots. The corners of the light pipe (101) near the lamps (301-304) are dual angled to reflect the light into the center of the display. The burn-out of a lamp (301-304) will not substantially affect the even lighting capabilities of the apparatus.
Inventors
- 👤 David L. Bond
- 👤 Kevin D. Kaschke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:12
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/0001; G02B6/0011; G02B6/0013; G02B6/0015; G02B6/002; G02B6/0021; G02B6/0033; G02B6/0035; G02B6/004; G02B6/0043; G02B6/0045; G02B6/0046; G02B6/005; G02B6/0055; G02B6/0058; G02B6/0061; G02B6/0066; G02B6/0068; G09; G09F; G09F13/00; G09F13/18; G09F2013/1804; G09F2013/1831
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
144 words
Apparatus for backlighting a liquid crystal display, comprising: (a) substantially transparent means for distributing light having sides, a top, and a bottom, at least one side of the sides having at least one recess; (b) at least one light source, positioned in the at least one recess, for providing the light; (c) first reflecting means for changing a path of the light exiting at least one side of the means for distributing light; (d) second reflecting means, positioned in at least one plane around the at least one light source, for reflecting the light; (e) a diffuse reflecting material disposed upon the bottom of the means for distributing light; and (f) a segment of the at least one side, between the at least one recess and a corner of the transparent means for distributing light, having a plurality of angles for reflecting the light.
Claim 2
Dependent Claim
144 words
Apparatus for backlighting a liquid crystal display, comprising: (a) substantially transparent means for distributing light having sides, a top, and a bottom, at least one side of the sides having at least one recess; (b) at least one light source, positioned in the at least one recess, for providing the light; (c) first reflecting means for changing a path of the light exiting at least one side of the means for distributing light; (d) second reflecting means, positioned in at least one plane around the at least one light source, for reflecting the light; (e) a diffuse reflecting material disposed upon the bottom of the means for distributing light; and (f) a segment of the at least one side, between the at least one recess and a corner of the transparent means for distributing light, having a plurality of angles for reflecting the light.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 wherein the at least one light source is an incandescent light bulb.
Claim 4
Dependent Claim
22 words
The apparatus of claim 1 wherein the means for distributing light is a flat light pipe comprised of a substantially transparent material.
Claim 5
Dependent Claim
14 words
The apparatus of claim 3 wherein the substantially transparent material is an acrylic material.
Claim 6
Dependent Claim
25 words
The apparatus of claim 1 wherein the top, a selective part of the bottom, and the sides of the means for distributing light are smooth.
Claim 7
Dependent Claim
23 words
The apparatus of claim 1 wherein the diffuse reflecting material disposed upon the bottom of the means for distribution light is white paint.
Claim 8
Dependent Claim
24 words
The apparatus of claim 1 wherein the diffuse reflective material is disposed such that the at least one light source provide evenly distributing light.
Claim 9
Dependent Claim
102 words
Apparatus for backlighting a liquid crystal display, comprising: (a) substantially transparent means for distributing light having sides, a top, and a bottom, at least one side of the sides having at least one recess; p1 (b) at least one light source, positioned in the at least one recess, for providing the light; (c) a diffuse reflecting material disposed upon the bottom of the means for distributing light; and (d) a segment of the at least one side, between the at least one recess and a corner of the transparent means for distributing light, having a plurality of angles for reflecting the light.
Claim 10
Dependent Claim
102 words
Apparatus for backlighting a liquid crystal display, comprising: (a) substantially transparent means for distributing light having sides, a top, and a bottom, at least one side of the sides having at least one recess; p1 (b) at least one light source, positioned in the at least one recess, for providing the light; (c) a diffuse reflecting material disposed upon the bottom of the means for distributing light; and (d) a segment of the at least one side, between the at least one recess and a corner of the transparent means for distributing light, having a plurality of angles for reflecting the light.
Claim 11
Dependent Claim
17 words
The apparatus of claim 8 wherein the at least one light source is an incandescent light bulb.
Claim 12
Dependent Claim
22 words
The apparatus of claim 8 wherein the means for distributing light is a flat light pipe comprised of a substantially transparent material.
Claim 13
Dependent Claim
14 words
The apparatus of claim 10 wherein the substantially transparent material is an acrylic material.
Claim 14
Dependent Claim
25 words
The apparatus of claim 8 wherein the top, a selective part of the bottom, and the side of the means for distributing light are smooth.
Claim 15
Dependent Claim
23 words
The apparatus of claim 8 wherein the diffuse reflecting material disposed upon the bottom of the means for distributing light is white paint.
Claim 16
Dependent Claim
253 words
Apparatus for backlighting a liquid crystal display, comprising: (a) a flat, substantially transparent means for distributing light, having four sides, wherein a first and a second opposing side each have a recess, each recess having at least one light source positioned therein for providing the light, the first and second opposing sides each having a plurality of angles between a corner of the means for distributing light and the recess, wherein light emitted from a light source of the at least one light source is reflected off the plurality of angles to substantially evenly distribute the light within the means for distributing light; (b) a first reflecting surface positioned on a third side of the means for distributing light and a second reflecting surface positioned on a fourth side of the means for distributing light, such that the light exiting the third and fourth sides is reflected into the means for distributing light; (c) a third reflecting surface, for reflecting the light, positioned in at least one plane around the at least one light source on the first opposing side; (d) a fourth reflecting surface, for reflecting the light, positioned in at least one plane around the at least one light source on the second opposing side; and (e) a diffuse reflecting material disposed on a bottom of the light pipe for diffusing light striking the bottom of the light pipe, the reflecting material disposed in such a manner as to substantially evenly distribute the light from the at least one light source.
Claim 17
Dependent Claim
253 words
Apparatus for backlighting a liquid crystal display, comprising: (a) a flat, substantially transparent means for distributing light, having four sides, wherein a first and a second opposing side each have a recess, each recess having at least one light source positioned therein for providing the light, the first and second opposing sides each having a plurality of angles between a corner of the means for distributing light and the recess, wherein light emitted from a light source of the at least one light source is reflected off the plurality of angles to substantially evenly distribute the light within the means for distributing light; (b) a first reflecting surface positioned on a third side of the means for distributing light and a second reflecting surface positioned on a fourth side of the means for distributing light, such that the light exiting the third and fourth sides is reflected into the means for distributing light; (c) a third reflecting surface, for reflecting the light, positioned in at least one plane around the at least one light source on the first opposing side; (d) a fourth reflecting surface, for reflecting the light, positioned in at least one plane around the at least one light source on the second opposing side; and (e) a diffuse reflecting material disposed on a bottom of the light pipe for diffusing light striking the bottom of the light pipe, the reflecting material disposed in such a manner as to substantially evenly distribute the light from the at least one light source.
Claim 18
Dependent Claim
19 words
The apparatus of claim 14 wherein the at least one light source is at least one incandescent light bulb.
Claim 19
Dependent Claim
22 words
The apparatus of claim 14 wherein the means for distributing light is a flat light pipe comprised of a substantially transparent material.
Claim 20
Dependent Claim
14 words
The apparatus of claim 16 wherein the substantially transparent material is an acrylic material.
Claim 21
Dependent Claim
25 words
The apparatus of claim 14 wherein the top, a selective part of the bottom, and the sides of the means for distributing light are smooth.
Claim 22
Dependent Claim
123 words
A communication apparatus, the apparatus comprising: (a) transmitting means: (b) receiving means; and (c) a liquid crystal display (LCD) module for displaying data, the module comprising: an LCD; and an LCD backlighting apparatus, comprising: substantially transparent means for distributing light having sides, a top, and a bottom, at least one side of the sides having at least one recess; at least one light source, positioned in the at least one recess, for providing the light; a diffuse reflecting material disposed upon the bottom of the means for distributing light; and a segment of the at least one side, between the at least one recess and a corner of the transparent means for distributing light, having a plurality of angles for reflecting the light.
Claim 23
Dependent Claim
123 words
A communication apparatus, the apparatus comprising: (a) transmitting means: (b) receiving means; and (c) a liquid crystal display (LCD) module for displaying data, the module comprising: an LCD; and an LCD backlighting apparatus, comprising: substantially transparent means for distributing light having sides, a top, and a bottom, at least one side of the sides having at least one recess; at least one light source, positioned in the at least one recess, for providing the light; a diffuse reflecting material disposed upon the bottom of the means for distributing light; and a segment of the at least one side, between the at least one recess and a corner of the transparent means for distributing light, having a plurality of angles for reflecting the light.
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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) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |