US4963933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
LED illuminator bar for copier
Assignee: HP Inc
•
Filing: 1988-10-05
•
Granted: 1990-10-16
•
Expires: 2008-10-05
Abstract
Abstract An erase bar for a xerographic printer, copier or the like has a row of light emitting diodes for illuminating a row of pixels across the photosensitive medium of the printer. Each LED is located in the bottom of a cavity. Next to the bottom of the cavity are concave reflective walls which reflect light emitted transversely from the LED toward an open end of the cavity. Reflective walls of the cavity provide multiple bounces of some of the light. Absorptive walls nearer the open end of the cavity absorb some of the light. These features combine to illuminate a pixel of desired shape and with approximately uniform intensity of illumination. Additional uniformity may be provided by passing the illumination through a window that is at least partly absorbing for smoothing out differences in intensity.
Inventors
- 👤 Kenneth G. Brownlee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:26
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/045; G03G15/047; B; B41; B41J; B41J2/00; B41J2/435; B41J2/447; B41J2/45; G03G2215/00; G03G2215/04; G03G2215/0429; G03G2215/0431; G03G2215/0448; G03G2215/0451; Y; Y10; Y10S; Y10S362/00; Y10S362/80
Claims Analysis
Total Claims: 57
Claim 1
Independent Claim
170 words
An illumination bar for a xerographic printer or the like comprising: a plurality of light sources in a row, each light source illuminating a separate area along the length of the illumination bar, adjacent illuminated areas being located so that the illumination along the length of the illumination bar is approximately uniform; each of the light sources comprising: a cavity open at an end facing in the direction of illumination by the illumination bar and closed at the opposite end; a light emitting diode at the closed end of the cavity for emitting radiation in directions transverse to the direction of illumination by the illumination bar; a concave reflective wall at the closed end of the cavity for reflecting a major portion of the light emitted by the light emitting diode in a direction toward the open end of the cavity; and occultation means between the reflective walls and the open end of the cavity for defining the shape of an image projected from the open end of the cavity.
Claim 2
Dependent Claim
170 words
An illumination bar for a xerographic printer or the like comprising: a plurality of light sources in a row, each light source illuminating a separate area along the length of the illumination bar, adjacent illuminated areas being located so that the illumination along the length of the illumination bar is approximately uniform; each of the light sources comprising: a cavity open at an end facing in the direction of illumination by the illumination bar and closed at the opposite end; a light emitting diode at the closed end of the cavity for emitting radiation in directions transverse to the direction of illumination by the illumination bar; a concave reflective wall at the closed end of the cavity for reflecting a major portion of the light emitted by the light emitting diode in a direction toward the open end of the cavity; and occultation means between the reflective walls and the open end of the cavity for defining the shape of an image projected from the open end of the cavity.
Claim 3
Dependent Claim
33 words
An illumination bar as recited in claim 1 wherein the means for defining an image shape comprises at least partly absorbing walls between the reflective walls and the open end of the cavity.
Claim 4
Dependent Claim
38 words
An illumination bar as recited in claim 1 wherein the means for defining an image shape comprises reflective walls having an aperture shape at the open end of the cavity similar to the shape of the projected image.
Claim 5
Dependent Claim
40 words
An illumination bar as recited in claim 1 wherein the concave reflective wall comprises a first relatively shallower cone nearer the closed end of the cavity and a second relatively steeper cone further from the closed end of the cavity.
Claim 6
Dependent Claim
18 words
An illumination bar as recited in claim 1 wherein the concave reflective wall comprises a continuous complex curve.
Claim 7
Dependent Claim
38 words
An illumination bar as recited in claim 1 further comprising a window over the open end of the cavity which is at least partially absorbing in a pattern for obtaining a desired illumination intensity uniformity from each cavity.
Claim 8
Dependent Claim
33 words
An illumination bar as recited in claim 1 further comprising a window over the open end of the cavity which includes a photochromic material for selectively darkening in response to differences in illumination.
Claim 9
Dependent Claim
36 words
An illumination bar as recited in claim 1 wherein at least the concave end of the cavity is metallized and the light emitting diode is a side emitting light emitting diode mounted on the metallized area.
Claim 10
Dependent Claim
40 words
An illumination bar as recited in claim 1 wherein the cavity has opposite parallel side walls and the light emitting diode is mounted on one parallel side wall of the cavity between the concave closed end and the open end.
Claim 11
Dependent Claim
93 words
An illumination array comprising: a plurality of cavities in a row, each cavity being closed at one end and open at the other end for projecting light toward an image plane, and comprising: a reflective closed end including a portion angled for reflecting light from the closed end toward the open end of the cavity, a cylindrical absorptive wall at the open end, and a cylindrical reflective wall between the absorptive wall and the concave closed end; and a light emitting diode mounted at the bottom of the closed end of each cavity.
Claim 12
Dependent Claim
93 words
An illumination array comprising: a plurality of cavities in a row, each cavity being closed at one end and open at the other end for projecting light toward an image plane, and comprising: a reflective closed end including a portion angled for reflecting light from the closed end toward the open end of the cavity, a cylindrical absorptive wall at the open end, and a cylindrical reflective wall between the absorptive wall and the concave closed end; and a light emitting diode mounted at the bottom of the closed end of each cavity.
Claim 13
Dependent Claim
40 words
An array as recited in claim 10 wherein the closed end comprises a flat bottom on the cavity, a first shallower cone adjacent the flat bottom and a second steeper cone between the first cone and the reflective cylindrical wall.
Claim 14
Dependent Claim
27 words
An array as recited in claim 10 wherein the cylindrical reflective wall is a right circular cylinder, and the cylindrical absorptive wall is a generally rectangular cylinder.
Claim 15
Dependent Claim
44 words
An array as recited in claim 10 further comprising a partially absorptive window at the open end of the cavity for absorbing a portion of the light from the cavity in selected areas of the window for obtaining a desired uniformity of illumination intensity.
Claim 16
Dependent Claim
23 words
An array as recited in claim 13 wherein each window includes a photochromic material for selectively darkening in response to differences in illumination.
Claim 17
Dependent Claim
23 words
An illumination bar as recited in claim 10 wherein the angled reflective wall is straight in a longitudinal cross section through the cavity.
Claim 18
Dependent Claim
23 words
An illumination bar as recited in claim 10 wherein the angled reflective wall is concave in a longitudinal cross section through the cavity.
Claim 19
Dependent Claim
32 words
An illumination bar as recited in claim 10 further comprising means for making electrical contact with each LED along the illumination bar for individually energizing each LED separately from the other LEDs.
Claim 20
Dependent Claim
35 words
An array as recited in claim 10 wherein at least the closed end of the cavity is metallized and the light emitting diode is a side emitting light emitting diode mounted on the metallized area.
Claim 21
Dependent Claim
131 words
An illumination bar for a xerographic printer or the like comprising: a printed circuit board; a plurality of light emitting diodes mounted in a row on the printed circuit board; a deflector plate mounted on the printed circuit board; a row of passages through the deflector plate, each passage being around a light emitting diode on the printed circuit board and having reflective walls concave in a direction away from the printed circuit board for reflecting light from the light emitting diode away from the printed circuit board; a aperture plate mounted on the deflector plate; a row of apertures through the aperture plate, each aperture being aligned with a passage through the deflector plate for passing light from the light emitting diode toward an image plane beyond the aperture plate.
Claim 22
Dependent Claim
131 words
An illumination bar for a xerographic printer or the like comprising: a printed circuit board; a plurality of light emitting diodes mounted in a row on the printed circuit board; a deflector plate mounted on the printed circuit board; a row of passages through the deflector plate, each passage being around a light emitting diode on the printed circuit board and having reflective walls concave in a direction away from the printed circuit board for reflecting light from the light emitting diode away from the printed circuit board; a aperture plate mounted on the deflector plate; a row of apertures through the aperture plate, each aperture being aligned with a passage through the deflector plate for passing light from the light emitting diode toward an image plane beyond the aperture plate.
Claim 23
Dependent Claim
20 words
An illumination bar as recited in claim 19 wherein each light emitting diode is a side emitting light emitting diode.
Claim 24
Dependent Claim
16 words
An illumination bar as recited in claim 19 wherein the walls of the apertures are absorptive.
Claim 25
Dependent Claim
27 words
An illumination bar as recited in claim 19 wherein each passage through the deflector plate includes a cylindrical wall between the concave walls and the aperture plate.
Claim 26
Dependent Claim
39 words
An illumination bar as recited in claim 19 wherein the reflective walls in the deflector plate comprise a first relatively shallower cone nearer the printed circuit board and a second relatively steeper cone further from the printed circuit board.
Claim 27
Dependent Claim
29 words
An illumination bar as recited in claim 19 wherein the passage through the deflector plate comprises a circular opening, and the aperture through the aperture plate comprises a rectangle.
Claim 28
Dependent Claim
15 words
An illumination bar as recited in claim 19 further comprising a window over the aperture.
Claim 29
Dependent Claim
27 words
An illumination bar as recited in claim 25 wherein the window is partially absorbing in a pattern for obtaining a desired illumination intensity uniformity from each cavity.
Claim 30
Dependent Claim
24 words
An illumination bar as recited in claim 25 wherein the window includes a photochromic material for selectively darkening in response to differences in illumination.
Claim 31
Dependent Claim
79 words
An illumination bar for a xerographic printer or the like comprising means for projecting a stripe of light formed of a plurality of adjacent generally rectangular pixels, each means for projecting comprising: a cavity with a generally rectangular aperture at one end of the cavity; a reflective concave closed end at the other end of the cavity; and a light emitting diode mounted in the closed end for emitting light toward at least the concave portion of the cavity.
Claim 32
Dependent Claim
79 words
An illumination bar for a xerographic printer or the like comprising means for projecting a stripe of light formed of a plurality of adjacent generally rectangular pixels, each means for projecting comprising: a cavity with a generally rectangular aperture at one end of the cavity; a reflective concave closed end at the other end of the cavity; and a light emitting diode mounted in the closed end for emitting light toward at least the concave portion of the cavity.
Claim 33
Dependent Claim
40 words
An illumination bar as recited in claim 28 wherein the cavity has opposite parallel side walls and the light emitting diode is mounted on one parallel side wall of the cavity between the concave closed end and the open end.
Claim 34
Dependent Claim
40 words
An illumination bar as recited in claim 28 wherein the concave reflective end comprises a first relatively shallower cone nearer the closed end of the cavity and a second relatively steeper cone further from the closed end of the cavity.
Claim 35
Dependent Claim
18 words
An illumination bar as recited in claim 28 wherein the concave reflective end comprises a continuous complex curve.
Claim 36
Dependent Claim
32 words
An illumination bar as recited in claim 28 further comprising means for making electrical contact with each LED along the illumination bar for individually energizing each LED separately from the other LEDs.
Claim 37
Dependent Claim
73 words
An illumination array comprising: a printed circuit board; a row of light emitting diodes mounted on the printed circuit board; a reflector plate on the printed circuit board including a scalloped edge with a row of indentations, each indentation encompassing a light emitting diode, each indentation having a reflective concave wall portion for reflecting light from the light emitting diode away from the reflector plate; and a cover plate over the reflector plate.
Claim 38
Dependent Claim
73 words
An illumination array comprising: a printed circuit board; a row of light emitting diodes mounted on the printed circuit board; a reflector plate on the printed circuit board including a scalloped edge with a row of indentations, each indentation encompassing a light emitting diode, each indentation having a reflective concave wall portion for reflecting light from the light emitting diode away from the reflector plate; and a cover plate over the reflector plate.
Claim 39
Dependent Claim
31 words
An illumination array as recited in claim 33 wherein such a concave wall portion is in the form of two continuous curves intersecting in a cusp behind the light emitting diode.
Claim 40
Dependent Claim
78 words
An illumination array comprising: a printed circuit board; a row of pits in the printed circuit board, each pit having walls angled for reflecting light from the bottom of the pit away from the printed circuit board; a metal layer on the printed circuit board including a portion adjacent to such a pit and a portion in such a pit; and a side emitting light emitting diode on the metal layer in the bottom of such a pit.
Claim 41
Dependent Claim
78 words
An illumination array comprising: a printed circuit board; a row of pits in the printed circuit board, each pit having walls angled for reflecting light from the bottom of the pit away from the printed circuit board; a metal layer on the printed circuit board including a portion adjacent to such a pit and a portion in such a pit; and a side emitting light emitting diode on the metal layer in the bottom of such a pit.
Claim 42
Dependent Claim
42 words
An illumination array comprising means for illuminating a plurality of adjacent pixels, each means for illuminating comprising a light source having a transparent window, and characterized by each window including a photochromic material for selectively darkening in response to differences in illumination.
Claim 43
Dependent Claim
42 words
An illumination array comprising means for illuminating a plurality of adjacent pixels, each means for illuminating comprising a light source having a transparent window, and characterized by each window including a photochromic material for selectively darkening in response to differences in illumination.
Claim 44
Dependent Claim
84 words
A xerographic printer or the like comprising: a movable photosensitive medium; and a plurality of means for projecting a plurality of separately addressable images directly on the photosensitive medium without a lens, each means for projecting comprising: a cavity with a generally rectangular aperture at one end of the cavity; a reflective concave closed end at the other end of the cavity; and a light emitting diode mounted in the closed end for emitting light toward at least the concave portion of the cavity.
Claim 45
Dependent Claim
84 words
A xerographic printer or the like comprising: a movable photosensitive medium; and a plurality of means for projecting a plurality of separately addressable images directly on the photosensitive medium without a lens, each means for projecting comprising: a cavity with a generally rectangular aperture at one end of the cavity; a reflective concave closed end at the other end of the cavity; and a light emitting diode mounted in the closed end for emitting light toward at least the concave portion of the cavity.
Claim 46
Dependent Claim
32 words
A xerographic printer or the like as recited in claim 37 wherein the aperture comprises at least partly absorbing walls between the reflective closed end and the open end of the cavity.
Claim 47
Dependent Claim
36 words
A xerographic printer or the like as recited in claim 37 wherein the aperture comprises reflective walls having an aperture shape at the open end of the cavity similar to the shape of the projected image.
Claim 48
Dependent Claim
172 words
An illumination bar for a xerographic printer or the like comprising: a plurality of light sources in a row, each light source illuminating a separate area along the length of the illumination bar, adjacent illuminated areas being located so that the illumination along the length of the illumination bar is approximately uniform; each of the light sources comprising: a cavity open at an end facing in the direction of illumination by the illumination bar and closed at the opposite end; a light emitting diode at the closed end of the cavity for emitting radiation in directions transverse to the direction of illumination by the illumination bar; a reflective wall at the closed end of the cavity for reflecting a major portion of the light emitted by the light emitting diode in a direction toward the open end of the cavity; and at least partly absorbing walls between the reflective walls and the open end of the cavity for defining the shape of an image projected from the open end of the cavity.
Claim 49
Dependent Claim
172 words
An illumination bar for a xerographic printer or the like comprising: a plurality of light sources in a row, each light source illuminating a separate area along the length of the illumination bar, adjacent illuminated areas being located so that the illumination along the length of the illumination bar is approximately uniform; each of the light sources comprising: a cavity open at an end facing in the direction of illumination by the illumination bar and closed at the opposite end; a light emitting diode at the closed end of the cavity for emitting radiation in directions transverse to the direction of illumination by the illumination bar; a reflective wall at the closed end of the cavity for reflecting a major portion of the light emitted by the light emitting diode in a direction toward the open end of the cavity; and at least partly absorbing walls between the reflective walls and the open end of the cavity for defining the shape of an image projected from the open end of the cavity.
Claim 50
Dependent Claim
22 words
An illumination bar as recited in claim 40 wherein the reflective wall is straight in a longitudinal cross section through the cavity.
Claim 51
Dependent Claim
22 words
An illumination bar as recited in claim 40 wherein the reflective wall is concave in a longitudinal cross section through the cavity.
Claim 52
Dependent Claim
32 words
An illumination bar as recited in claim 40 further comprising means for making electrical contact with each LED along the illumination bar for individually energizing each LED separately from the other LEDs.
Claim 53
Dependent Claim
107 words
An illumination bar for a xerographic printer or the like comprising means for projecting a stripe of light formed of a plurality of adjacent generally rectangular pixels, each means for projecting comprising: a cavity with a generally rectangular absorptive walls forming an aperture at one end of the cavity; a reflective closed end at the other end of the cavity having a portion angled for reflecting a major part of the light striking the reflective angled portion toward the open end of the cavity; and a light emitting diode mounted in the closed end for emitting light toward at least the angled reflective portion of the cavity.
Claim 54
Dependent Claim
107 words
An illumination bar for a xerographic printer or the like comprising means for projecting a stripe of light formed of a plurality of adjacent generally rectangular pixels, each means for projecting comprising: a cavity with a generally rectangular absorptive walls forming an aperture at one end of the cavity; a reflective closed end at the other end of the cavity having a portion angled for reflecting a major part of the light striking the reflective angled portion toward the open end of the cavity; and a light emitting diode mounted in the closed end for emitting light toward at least the angled reflective portion of the cavity.
Claim 55
Dependent Claim
23 words
An illumination bar as recited in claim 44 wherein the angled reflective wall is straight in a longitudinal cross section through the cavity.
Claim 56
Dependent Claim
23 words
An illumination bar as recited in claim 44 wherein the angled reflective wall is concave in a longitudinal cross section through the cavity.
Claim 57
Dependent Claim
32 words
An illumination bar as recited in claim 44 further comprising means for making electrical contact with each LED along the illumination bar for individually energizing each LED separately from the other LEDs.
References Cited (Backward Citations)
US4255042A
Cited
US4344691A
Cited
US4435064A
Cited
US4552447A
Cited
US4585330A
Cited
US4767172A
Cited
US4640601A
Cited
US4576464A
Cited
US4728982A
Cited
US4720729A
Cited
US4611906A
Cited
US4734734A
Cited
JPS6223072A
Cited
JPS62103668A
Cited
JPS62103669A
Cited
JPS62103670A
Cited
JPS62119562A
Cited
US4796052A
Cited
US4759603A
Cited
US4814667A
Cited
US4843427A
Cited
US4794424A
Cited
US4837598A
Cited
US4928142A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |