US4916464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Light emitting diode array print head having no bonding wire connections
Assignee: Oki Electric Industry Co Ltd
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Filing: 1989-05-04
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Granted: 1990-04-10
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Expires: 2009-05-04
Abstract
Abstract An LED array print head for an electrophotographic printer includes: LED array device packages each being loaded with an array of LEDs individually connected to a first major surface of the LED package by first solder joints; LED driver packages each loaded with a driver circuit connected to a first major surface of the driver package by second solder joints; and an optically transparent insulative substrate with a first major surface carrying conductive leads adapted to electrically connect the LEDs and driver circuits. The LED and driver packages are mounted on the substrate in such an orientation that the first major surfaces of the packages face the first major surface of the substrate and the first and second solder joints are connected to the conductive leads of the substrate.
Inventors
- 👤 Katsuyuki Ito
- 👤 Naoji Akutsu
- 👤 Yuhei Itasaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:17
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1238; G06K15/1242; G06K15/1247; B; B41; B41J; B41J2/00; B41J2/435; B41J2/447; B41J2/45
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
205 words
A light emitting diode array print head comprising: a first package having opposite major surfaces on a first of which an array of light emitting diodes are positioned, said first major surface being provided with electrode conductor means which is connected to said light emitting diodes, said electrode conductor means being provided with first solder bumps which are made of a thermally fusible alloy; a second package loaded with a driver circuit for driving said array of light emitting diodes, a first of opposite major surface of said second package being provided with second solder bumps which are made of a thermally fusible alloy and are connected to said driver circuit; a substrate formed of an optically transparent insulative material and having opposite major surfaces on a first of which are provided conductive lead means for electrically connecting said light emitting diodes and said driver circuit; and said first package and said second package being mounted on said substrate in such an orientation that said first major surface of said first package and said first major surface of said second package face said first major surface of said substrate, said first solder bumps and said second solder bumps being connected to said conductive lead means.
Claim 2
Dependent Claim
205 words
A light emitting diode array print head comprising: a first package having opposite major surfaces on a first of which an array of light emitting diodes are positioned, said first major surface being provided with electrode conductor means which is connected to said light emitting diodes, said electrode conductor means being provided with first solder bumps which are made of a thermally fusible alloy; a second package loaded with a driver circuit for driving said array of light emitting diodes, a first of opposite major surface of said second package being provided with second solder bumps which are made of a thermally fusible alloy and are connected to said driver circuit; a substrate formed of an optically transparent insulative material and having opposite major surfaces on a first of which are provided conductive lead means for electrically connecting said light emitting diodes and said driver circuit; and said first package and said second package being mounted on said substrate in such an orientation that said first major surface of said first package and said first major surface of said second package face said first major surface of said substrate, said first solder bumps and said second solder bumps being connected to said conductive lead means.
Claim 3
Dependent Claim
36 words
A print head in accordance with claim 1, wherein said substrate has a generally elongate shape, and said array of light emitting diodes extends linearly in a longitudinal direction of the elongate shape of said substrate.
Claim 4
Dependent Claim
53 words
A print head in accordance with claim 2, wherein a plurality of first packages and a plurality of second packages are arranged parallel to each other along a longitudinal axis of said elongate shape of said substrate, said arrays of light emitting diodes of said first packages being aligned along said longitudinal axis.
Claim 5
Dependent Claim
77 words
An electrophotographic printer comprising: an LED array print head in accordance with claim 3 located above a photoconductive surface of a photoconductive drum such that said longitudinal axis of said elongate shape extends substantially parallel to a longitudinal axis of said drum; and focusing optics extending along said longitudinal axis of said elongate shape for focusing light which is emitted by said arrays of light emitting diodes via said substrate onto said photoconductive surface of said drum.
Claim 6
Dependent Claim
61 words
A print head in accordance with claim 1, wherein said conductive lead means comprises: first conductive leads connecting anodes of said array of light emitting diodes individually to said driver circuit; a second conductive lead connecting cathodes of said array of light emitting diodes commonly to an external circuit; and third conductive leads connecting said driver circuit to an external circuit.
Claim 7
Dependent Claim
27 words
A print head in accordance with claim 1, further comprising optics for focusing light which is emitted by said array of light emitting diodes via said substrate.
Claim 8
Dependent Claim
114 words
A print head in accordance with claim 1, wherein said electrode conductor means comprises a plurality of first electrode conductors each of which is connected to one electrode of a respective one of said light emitting diodes, and further comprising a second electrode conductor provided on a second major surface of said first package and commonly connected to the other electrode of all of said light emitting diodes, and resilient biasing means for biasing said other major surface of said first package toward said substrate, said biasing means including a first resilient and conductive flat plate which has a free end portion electrically connected to said second electrode conductor and biasing said first package.
Claim 9
Dependent Claim
62 words
A print head in accordance with claim 7, wherein said biasing means comprises a second resilient and conductive flat plate which is interposed between said second electrode conductor and said free end portion to electrically interconnect said second electrode and said free end portion and to damp a pressure force which is exerted by said free end portion on said first package.
Claim 10
Dependent Claim
36 words
A print head in accordance with claim 7, wherein the first conductive flat plate is thermally conductive so that heat generated in said first package is at least partly radiated via said first conductive flat plate.
Claim 11
Dependent Claim
54 words
A print head in accordance with claim 9, wherein said free end portion is extended to such an extent that said free end portion makes contact with the other major surface of said second package which is remote from said substrate, whereby said first conductive flat plate is thermally connected to said second package.
Claim 12
Dependent Claim
36 words
A print head in accordance with claim 7, wherein said substrate has a generally elongate shape, and said array of light emitting diodes extends linearly in a longitudinal direction of the elongate shape of said substrate.
Claim 13
Dependent Claim
53 words
A print head in accordance with claim 11, wherein a plurality of first packages and a plurality of second packages are arranged parallel to each other along a longitudinal axis of said elongate shape of said substrate, said arrays of light emitting diodes of said first packages being aligned along said longitudinal axis.
Claim 14
Dependent Claim
77 words
An electrophotographing printer comprising: an LED array print head in accordance with claim 12, located above a photoconductive surface of a photoconductive drum such that said longitudinal axis of said elongate shape extends substantially parallel to a longitudinal axis of said drum; and focusing optics extending along said longitudinal axis of said elongate shape for focusing light which is emitted by said arrays of light emitting diodes via said substrate onto said photoconductive surface of said drum.
Claim 15
Dependent Claim
46 words
An electrophotographic printer in accordance with claim 13, wherein said first conductive flat plate is thermally conductive and is thermally connected to a structural body of said printer, whereby heat generated in said first packages is at least partly radiated via said first conductive flat plate.
Claim 16
Dependent Claim
29 words
A print heat in accordance with claim 7, wherein said one electrode of each of the light emitting diodes is an anode and said other electrode is a cathode.
Claim 17
Dependent Claim
65 words
A print head in accordance with claim 15, wherein the conductive lead means comprises first conductive leads connecting said anodes of said array of light emitting electrodes individually to said driver circuit, and second conductive leads connecting said driver circuit to the external circuit and said first conductive flat plate connects said cathodes of said array of light emitting diodes commonly to the external circuit.
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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) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |