US4878072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
LED age correction means
Assignee: Canon Production Printing Netherlands BV
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Filing: 1988-09-08
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Granted: 1989-10-31
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Expires: 2008-09-08
Abstract
Abstract An aging correction system for an LED array in a printer, in which each LED can be energized during a variable time and in which a light sensor, with which the relative light-output of each LED can be measured and compared with earlier measured values, is disposed near the array, and in which on the basis of these measured values a new correction value is determined.
Inventors
- 👤 Hans Reinten
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 02:58
CPC Classifications
G; G06; G06K; G06K15/00; G06K15/02; G06K15/12; G06K15/1238; G06K15/1242; G06K15/1247
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
153 words
An exposure device for line and imagewise exposure of a photosensitive layer, comprising: a. an array of LED's; b. a control device connected to said LED array to energize each LED individually for a variable time per image line by means of an absolute correction number; c. a memory means connected to said control device and including a first table for storing the relative intensity of each LED and an aging table for storing for each individual LED the light intensity thereof measured by said light-sensor; and d. at least one light-sensor smaller than said array of LED's, said sensor being located a fixed distance from said LED array for measuring the relative light intensity of each individual LED connected to said control device; whereby said control device determines a new absolute correction number for each LED based on said data stored in said aging table and corresponding data in said first table.
Claim 2
Dependent Claim
153 words
An exposure device for line and imagewise exposure of a photosensitive layer, comprising: a. an array of LED's; b. a control device connected to said LED array to energize each LED individually for a variable time per image line by means of an absolute correction number; c. a memory means connected to said control device and including a first table for storing the relative intensity of each LED and an aging table for storing for each individual LED the light intensity thereof measured by said light-sensor; and d. at least one light-sensor smaller than said array of LED's, said sensor being located a fixed distance from said LED array for measuring the relative light intensity of each individual LED connected to said control device; whereby said control device determines a new absolute correction number for each LED based on said data stored in said aging table and corresponding data in said first table.
Claim 3
Dependent Claim
42 words
An exposure device according to claim 1, in which the array of LED's comprises a number of individual partial arrays which are disposed on a support together with a number of control circuits and wherein said light-sensors are disposed on said support.
Claim 4
Dependent Claim
27 words
An exposure device according to claim 1 or 2, wherein said control device delivers a warning signal when a new absolute correction number exceeds a predetermined value.
Claim 5
Dependent Claim
59 words
An exposure device comprising a partial array of LED's mounted on a support means, an associated control circuit mounted on said support means and having a memory for storing an aging table, and a light sensor mounted on said support for measuring the relative intensity of light from said array, said sensor being smaller in size than said array.
Claim 6
Dependent Claim
59 words
An exposure device comprising a partial array of LED's mounted on a support means, an associated control circuit mounted on said support means and having a memory for storing an aging table, and a light sensor mounted on said support for measuring the relative intensity of light from said array, said sensor being smaller in size than said array.
Claim 7
Dependent Claim
33 words
An exposure device as set forth in claim 4 wherein said support means comprises a plurality of individual supports each including a partial array of LED's with associated control circuit and light sensor.
Claim 8
Dependent Claim
77 words
An array of LED's mounted on a support means, an associated control circuit for said array mounted on said support means and having included therein a memory means having at least an aging table stored therein, and a light sensor for measuring the relative intensity of each LED in said array, said sensor being of a size smaller than said array, whereby said support is adapted to be configured with other supports to comprise an exposure device.
Claim 9
Dependent Claim
77 words
An array of LED's mounted on a support means, an associated control circuit for said array mounted on said support means and having included therein a memory means having at least an aging table stored therein, and a light sensor for measuring the relative intensity of each LED in said array, said sensor being of a size smaller than said array, whereby said support is adapted to be configured with other supports to comprise an exposure device.
References Cited (Backward Citations)
US4477821A
Cited
US4799071A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-30 | 1993-05-01 | 1993-10-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-30 | 1997-05-01 | 1997-10-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-30 | 2001-05-01 | 2001-10-31 | $7700.00 | Window Closed / Lapsed |