US3640246A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Development apparatus for latent electrostatic images
Assignee: Xerox Corp
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Filing: 1969-11-07
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Granted: 1972-02-08
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Expires: 1989-11-07
Abstract
Abstract Powder cloud development apparatus for developing latent electrostatic images including an ion generator adjacent one wall of the development chamber. A cloud of toner particles is introduced into the development chamber through a port in the wall directly opposite the ion generator wall. Above the powder cloud port and the apertures in the ion generator wall, and extending completely between the opposed walls, is a baffle under which the powder and toner clouds meet and are thoroughly mixed. A grid electrode, positioned above the baffle and spaced much further from the photoconductive surface than a conventional powder cloud development electrode, is utilized to control image quality and contrast.
Inventors
- 👤 Lothar S Jeromin
- 👤 Hazen L Hoyt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:30
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/06; G03G15/08; G03G15/0803; Y; Y10; Y10S; Y10S118/00; Y10S118/05
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
200 words
An apparatus for developing a latent electrostatic image on a surface comprising a chamber having a pair of opposed sidewalls, support means for supporting said surface with its latent electrostatic image-bearing side facing said chamber, means for supplying a cloud of developer particles to said chamber through a port in one of said opposed sidewalls, ion generator means for supplyIng a cloud of ions to said chamber through at least one port in the other of said opposed sidewalls, means to maintain said ion generator means at a higher pressure than said chamber whereby developer particles are substantially prevented from entering said ion generator means, a baffle overlying said ports through which said developer particles and said ions are introduced into said chamber, said baffle extending completely from one of said opposed sidewalls to the other of said opposed sidewalls whereby said ion cloud and said developer particle cloud initially meet and mix under said baffle, a grid electrode positioned between said latent electrostatic image-bearing surface and said baffle, and means to bias said grid electrode, said grid electrode being spaced from the latent electrostatic image-bearing surface a distance sufficient to control the contrast and quality of the developed image.
Claim 2
Independent Claim
200 words
An apparatus for developing a latent electrostatic image on a surface comprising a chamber having a pair of opposed sidewalls, support means for supporting said surface with its latent electrostatic image-bearing side facing said chamber, means for supplying a cloud of developer particles to said chamber through a port in one of said opposed sidewalls, ion generator means for supplyIng a cloud of ions to said chamber through at least one port in the other of said opposed sidewalls, means to maintain said ion generator means at a higher pressure than said chamber whereby developer particles are substantially prevented from entering said ion generator means, a baffle overlying said ports through which said developer particles and said ions are introduced into said chamber, said baffle extending completely from one of said opposed sidewalls to the other of said opposed sidewalls whereby said ion cloud and said developer particle cloud initially meet and mix under said baffle, a grid electrode positioned between said latent electrostatic image-bearing surface and said baffle, and means to bias said grid electrode, said grid electrode being spaced from the latent electrostatic image-bearing surface a distance sufficient to control the contrast and quality of the developed image.
Claim 3
Dependent Claim
16 words
The apparatus of claim 1 wherein said ion generator means is positioned external to said chamber.
Claim 4
Dependent Claim
67 words
The apparatus of claim 1 wherein said ion generator means is positioned within said chamber, said ion generator means having a housing having at least one corona emitting wire therein, that portion of said ion generator housing beneath said baffle and opposite said developer particle port at least partially defining the opposed sidewall of said chamber through which said cloud of ions is introduced into said chamber
Claim 5
Dependent Claim
49 words
The apparatus of claim 1 further including means for introducing under pressure an ionizable gas to said ion generator means whereby the flow of said pressurized gas carries ions formed within said ion generator means through said ion generator ports into that portions of said chamber beneath said baffle.
Claim 6
Dependent Claim
82 words
The apparatus of claim 1 wherein said ion generator means comprises a housing having at least one corona emitting wire therein, and means to introduce under pressure an ionizable gas to said housing adjacent only the ends of said corona emitting wire, whereby the normal flow of the ionizable gas is along the length of said corona wire to about the midpoint thereof where the ion cloud exits through said ion generator ports into that portion of said chamber beneath said baffle.
Claim 7
Dependent Claim
13 words
The apparatus of claim 5 further including means to energize said corona wire.
Claim 8
Dependent Claim
12 words
The apparatus of claim 6 wherein said corona wire is energized intermittently.
Claim 9
Dependent Claim
21 words
The apparatus of claim 1 wherein said means for supplying a cloud of developer particles to said chamber is pulsed intermittently.
Claim 10
Dependent Claim
28 words
The apparatus of claim 1 wherein said grid electrode is spaced on the order of about 1 inch to about 2 inches from the latent electrostatic image-bearing surface.
Claim 11
Dependent Claim
29 words
The apparatus of claim 1 further including means for causing relative movement of said development chamber and said latent electrostatic image-bearing surface whereby a leaktight development chamber is defined.
Claim 12
Dependent Claim
62 words
The apparatus of claim 1 wherein said baffle has an upper flat portion and downwardly depending side portions, whereby there is defined a zone within said chamber beneath said baffle where said ion cloud and said toner cloud initially meet and mix prior to movement of the charged toner cloud to the top of said chamber adjacent said latent electrostatic image-bearing surface.
Claim 13
Dependent Claim
17 words
The apparatus of claim 11 wherein said side portions are angled outwardly from said upper flat portion.
Claim 14
Dependent Claim
15 words
The apparatus of claim 1 further including means to remove unused toner from said chamber.
Claim 15
Dependent Claim
25 words
The apparatus of claim 1 further including a grid electrode adjacent the bottom wall of said chamber in those areas not directly beneath said baffle.
Claim 16
Dependent Claim
52 words
The apparatus of claim 1 further including means adjacent the walls defining said chamber for permitting the establishment of a pressure differential between the inside of said chamber and the outside of said chamber, said means assisting in the maintenance of the pressure differential established between said ion generator and said chamber.
Claim 17
Dependent Claim
24 words
THe apparatus of claim 15 wherein said means comprises porous pads of limited porosity such that air but not developer particles can pass therethrough.
Claim 18
Dependent Claim
33 words
The apparatus of claim 1 further including delay means connected to said ion generator means and said developer cloud generator for enabling developer particles to be supplied to said chamber before free ions.
Claim 19
Dependent Claim
25 words
The apparatus of claim 1 wherein said ionizable gas is continuously introduced into said ion generator housing during the development of the latent electrostatic image.
Claim 20
Independent Claim
325 words
An apparatus for developing a latent electrostatic image on a surface comprising a chamber having a pair of opposed sidewalls; means for supporting said surface with its latent electrostatic image-bearing side facing inwardly toward said chamber; a baffle extending completely from one of said opposed sidewalls to the other of said opposed sidewalls, said baffle being spaced from the remaining sidewalls whereby material introduced into said chamber under said baffle can move from beneath said baffle to the top of said development chamber; means for supplying a cloud of developer particles to said chamber through a port in one of said opposed sidewalls, said port being positioned in said sidewall beneath said baffle; ion generator means for supplying a cloud of ions to said chamber through at least one port in the other of said opposed sidewalls, all of said ion generator ports being positioned beneath said baffle, said ion generator means comprising a housing having at least one corona emitting means therein, means to energize said corona emitting means, means to introduce under pressure an ionizable gas to said housing whereby the flow of said pressurized gas carries ions formed within said ion generator means through said ion generator ports into that portion of said chamber beneath said baffle; means to maintain said ion generator means at a higher pressure than said chamber whereby developer particles are substantially prevented from entering said ion generator means; means adjacent the walls defining said chamber for permitting the establishment of a pressure differential between the inside of said chamber and the outside of said chamber, said means assisting in the maintenance of the pressure differential established between said ion generator and said chamber; a grid electrode positioned between said latent electrostatic image-bearing surface and said baffle, said grid electrode being spaced from the latent electrostatic image-bearing surface a distance sufficient to control the contrast and quality of the developed image; and means to bias said grid electrode.
Claim 21
Independent Claim
325 words
An apparatus for developing a latent electrostatic image on a surface comprising a chamber having a pair of opposed sidewalls; means for supporting said surface with its latent electrostatic image-bearing side facing inwardly toward said chamber; a baffle extending completely from one of said opposed sidewalls to the other of said opposed sidewalls, said baffle being spaced from the remaining sidewalls whereby material introduced into said chamber under said baffle can move from beneath said baffle to the top of said development chamber; means for supplying a cloud of developer particles to said chamber through a port in one of said opposed sidewalls, said port being positioned in said sidewall beneath said baffle; ion generator means for supplying a cloud of ions to said chamber through at least one port in the other of said opposed sidewalls, all of said ion generator ports being positioned beneath said baffle, said ion generator means comprising a housing having at least one corona emitting means therein, means to energize said corona emitting means, means to introduce under pressure an ionizable gas to said housing whereby the flow of said pressurized gas carries ions formed within said ion generator means through said ion generator ports into that portion of said chamber beneath said baffle; means to maintain said ion generator means at a higher pressure than said chamber whereby developer particles are substantially prevented from entering said ion generator means; means adjacent the walls defining said chamber for permitting the establishment of a pressure differential between the inside of said chamber and the outside of said chamber, said means assisting in the maintenance of the pressure differential established between said ion generator and said chamber; a grid electrode positioned between said latent electrostatic image-bearing surface and said baffle, said grid electrode being spaced from the latent electrostatic image-bearing surface a distance sufficient to control the contrast and quality of the developed image; and means to bias said grid electrode.
Claim 22
Dependent Claim
16 words
The apparatus of claim 19 wherein said ion generator means is positioned external to said chamber.
Claim 23
Dependent Claim
43 words
The apparatus of claim 19 wherein that portion of said ion generator housing beneath said baffle and opposite said developer particle port at least partially defines the opposed sidewall of said chamber through which said cloud of ions is introduced into said chamber
Claim 24
Dependent Claim
64 words
The apparatus of claim 19 wherein said pressurized gas is introduced to said ion generator housing only adjacent the ends of said corona emitting means, whereby the flow of ionizable gas is along the length of said corona emitting means to about the midpoint thereof where the ion cloud exits through said ion generator ports into that portion of said chamber beneath said baffle.
Claim 25
Dependent Claim
13 words
The apparatus of claim 19 wherein said corona emitting means is energized intermittently.
Claim 26
Dependent Claim
21 words
The apparatus of claim 19 wherein said means for supplying a cloud of developer particles to said chamber is pulsed intermittently.
Claim 27
Dependent Claim
35 words
The apparatus of claim 24 further including means to cause said means for supplying a cloud of developer particles to said chamber to be pulsed at least once before said corona emitting means is energized.
Claim 28
Dependent Claim
28 words
The apparatus of claim 19 wherein said grid electrode is spaced on the order of about 1 inch to about 2 inches from the latent electrostatic image-beaRing surface.
Claim 29
Dependent Claim
64 words
The apparatus of claim 19 wherein said baffle has an upper flat portion and outwardly and downwardly depending side portions, whereby there is defined a zone within said chamber beneath said baffle where said ion cloud and said developer cloud initially meet and mix prior to movement of the charged developer cloud to the top of said chamber adjacent said latent electrostatic image-bearing surface.
Claim 30
Dependent Claim
40 words
The apparatus of claim 19 wherein said means for permitting the establishment of a pressure differential between the inside and outside of said chamber comprises porous pads of limited porosity such that air but not developer particles can pass therethrough.
Claim 31
Independent Claim
138 words
An apparatus for developing a latent electrostatic image on a surface comprising a chamber having a pair of opposed sidewalls, support means for supporting said surface with its latent electrostatic image-bearing side facing said chamber, means for supplying a cloud of charged developer particles to said chamber through a port in one of said opposed walls, a baffle overlying said port through which said developer particles are introduced into said chamber, said baffle extending completely from one of said opposed sidewalls to the other of said opposed sidewalls, a grid electrode positioned between said latent electrostatic image-bearing surface and said baffle, and means to bias said grid electrode to a desired potential and polarity, said grid electrode being spaced from the latent electrostatic image-bearing surface a distance sufficient to control the contrast and quality of the developed image.
Claim 32
Independent Claim
138 words
An apparatus for developing a latent electrostatic image on a surface comprising a chamber having a pair of opposed sidewalls, support means for supporting said surface with its latent electrostatic image-bearing side facing said chamber, means for supplying a cloud of charged developer particles to said chamber through a port in one of said opposed walls, a baffle overlying said port through which said developer particles are introduced into said chamber, said baffle extending completely from one of said opposed sidewalls to the other of said opposed sidewalls, a grid electrode positioned between said latent electrostatic image-bearing surface and said baffle, and means to bias said grid electrode to a desired potential and polarity, said grid electrode being spaced from the latent electrostatic image-bearing surface a distance sufficient to control the contrast and quality of the developed image.
Claim 33
Dependent Claim
22 words
The apparatus of claim 29 wherein said means for supplying a cloud of charged developer particles to said chamber is pulsed intermittently.
Claim 34
Dependent Claim
28 words
The apparatus of claim 29 wherein said grid electrode is spaced on the order of about 1 inch to about 2 inches from the latent electrostatic image-bearing surface.
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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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |