US5640190A — Non-impact printer with evenness control

Claim 1

Independent Claim 153 words

A non-impact printer for forming an image on a medium, which printer comprises: a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources; means for developing said latent image into a visual image; means for transferring said visual image onto said medium; first correction storage means for storing first correction factors derived from measurements of non-uniformity of average energy output of said recording sources of said sub-sets of recording sources; first correction means for applying, for each sub-set of recording sources, said first correction factors; second correction storage means for storing second correction factors derived from said measurements of non-uniformities of energy being output by each one of said individual recording sources, after said first correction factors have been applied; and second correction means for applying said second correction factors after applying said first correction factors.

Claim 2

Dependent Claim 153 words

A non-impact printer for forming an image on a medium, which printer comprises: a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources; means for developing said latent image into a visual image; means for transferring said visual image onto said medium; first correction storage means for storing first correction factors derived from measurements of non-uniformity of average energy output of said recording sources of said sub-sets of recording sources; first correction means for applying, for each sub-set of recording sources, said first correction factors; second correction storage means for storing second correction factors derived from said measurements of non-uniformities of energy being output by each one of said individual recording sources, after said first correction factors have been applied; and second correction means for applying said second correction factors after applying said first correction factors.

Claim 3

Dependent Claim 22 words

A printer according to claim 1, including means for measuring the average energy output of each of said sub-sets of recording sources.

Claim 4

Dependent Claim 21 words

A printer according to claim 1, including means for measuring the energy output of each individual one of said recording sources.

Claim 5

Dependent Claim 70 words

A printer according to claim 1, which further comprises: third correction storage means for storing third correction factors derived from a measurement of unevenness of optical density of a printed image printed after the application of said first and second correction factors; and third correction means for providing a correction of the unevenness of the optical density of the image to be printed according to said stored third correction factors.

Claim 6

Dependent Claim 28 words

A printer according to claim 4, including means for measuring the optical density of said printed image printed after the application of said first and second correction factors.

Claim 7

Dependent Claim 50 words

A printer according to claim 1, wherein said recording sources comprise a source of constant current as a current mirror circuit and said current mirror circuit produces a current for a respective recording source, which current is proportional to a reference selected from a reference current and a reference voltage.

Claim 8

Dependent Claim 27 words

A printer according to claim 1, wherein said second correction means corrects gradation data for each recording source according to a the respective said second correction factor.

Claim 9

Dependent Claim 36 words

A printer according to claim 1, wherein said second correction storage means comprises a look-up table storing, for each gradation value and for each recording source, a corrected gradation value derived from said second correction factors.

Claim 10

Dependent Claim 52 words

A printer according to claim 7, wherein said second correction storage means comprises: (i) a first look-up table storing recording source class numbers, and (ii) a second look-up table storing, for each gradation value and for each recording source class number, a corrected gradation data value derived from said second correction factors.

Claim 11

Dependent Claim 74 words

A printer according to claim 1, wherein said first correction means comprises for each sub-set of recording sources a shift register for transferring the said first correction factors to a latch register temporarily storing said first correction factors, while applying the first correction factors to a digital-to-analog converter generating a reference selected from a reference current and a reference voltage, which reference controls the average energy level output by said subset of recording sources.

Claim 12

Dependent Claim 16 words

A printer according to claim 1, wherein said first correction storage means comprises a non-volatile memory.

Claim 13

Dependent Claim 18 words

A printer according to claim 1, wherein said second correction storage means is in comprises a non-volatile memory.

Claim 14

Independent Claim 160 words

A method of adjusting a non-impact printer for forming an image on a medium, which printer comprises: a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources; means for developing said latent image into a visual image; means for transferring said visual image onto said medium; the method comprising the steps of: measuring average energy output of each of said sub-sets of recording sources; generating and storing first correction factors derived from measurements of non-uniformity of the energy output of said sub-sets of recording sources; applying, for each sub-set of recording sources, said first correction factors; measuring energy output of each individual one of said recording sources; generating and storing second correction factors derived from said measurements of non-uniformity of the energy output of each individual one of said recording sources; and applying said second correction factors after applying said first correction factors.

Claim 15

Independent Claim 160 words

A method of adjusting a non-impact printer for forming an image on a medium, which printer comprises: a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources; means for developing said latent image into a visual image; means for transferring said visual image onto said medium; the method comprising the steps of: measuring average energy output of each of said sub-sets of recording sources; generating and storing first correction factors derived from measurements of non-uniformity of the energy output of said sub-sets of recording sources; applying, for each sub-set of recording sources, said first correction factors; measuring energy output of each individual one of said recording sources; generating and storing second correction factors derived from said measurements of non-uniformity of the energy output of each individual one of said recording sources; and applying said second correction factors after applying said first correction factors.

Claim 16

Dependent Claim 86 words

A method according to claim 13, further comprising the steps of: printing one or more images of an optical density after the application of said first and second correction factors; measuring unevenness of optical density of said or more printed image; generating and storing third correction factors derived from the unevenness of the optical density of said at least one printed image; and providing a correction of the unevenness of the optical density of the image to be printed according to said stored third correction factors.

Claim 17

Dependent Claim 23 words

A method according to claim 14, wherein said third correction factors are combined with said second correction factors to produce combined correction factors.

Claim 18

Dependent Claim 152 words

A non-impact printer for forming an image on a medium, which printer comprises: a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources; means for developing said latent image into a visual image; means for transferring said visual image onto said medium; means for storing correction factors K i derived from measurements of non-uniformity of each individual one of said recording sources; and correction means for applying said correction factors; wherein said recording sources are classified in a plurality of classes, based upon their respective correction factor K i , each of such classes comprising recording sources having about a same factor K c , and each recording source is then corrected using said correction factor K c , which is representative for all recording sources of the class to which that recording source belongs.

Claim 19

Dependent Claim 152 words

A non-impact printer for forming an image on a medium, which printer comprises: a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources; means for developing said latent image into a visual image; means for transferring said visual image onto said medium; means for storing correction factors K i derived from measurements of non-uniformity of each individual one of said recording sources; and correction means for applying said correction factors; wherein said recording sources are classified in a plurality of classes, based upon their respective correction factor K i , each of such classes comprising recording sources having about a same factor K c , and each recording source is then corrected using said correction factor K c , which is representative for all recording sources of the class to which that recording source belongs.

Claim 20

Dependent Claim 56 words

A method according to claim 13, wherein said recording sources are classified in a plurality of classes, based upon respective said second correction factors thereof, each of such classes comprising recording sources having about a same factor K c , which is representative for all recording sources of the class to which that recording source belongs.

Claim 21

Dependent Claim 127 words

A recording head comprising: a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources; first correction storage means for storing first correction factors K i derived from measurements of non-uniformity of average energy output of said recording sources of said sub-sets of recording sources; first correction means for applying, for each sub-set of recording sources, said first correction factors; second correction storage means for storing second correction factors derived from said measurements of non-uniformities of energy being output by each one of said individual recording sources, after said first correction factors have been applied; and second correction means for applying said second correction factors after applying said first correction factors.

Claim 22

Dependent Claim 127 words

A recording head comprising: a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources; first correction storage means for storing first correction factors K i derived from measurements of non-uniformity of average energy output of said recording sources of said sub-sets of recording sources; first correction means for applying, for each sub-set of recording sources, said first correction factors; second correction storage means for storing second correction factors derived from said measurements of non-uniformities of energy being output by each one of said individual recording sources, after said first correction factors have been applied; and second correction means for applying said second correction factors after applying said first correction factors.

Claim 23

Dependent Claim 71 words

A recording head according to claim 18, which further comprises: third correction storage means for storing third correction factors derived from a measurement of unevenness of optical density of the a printed image printed after application of said first and second correction factors; and third correction means for providing a correction of the unevenness of the optical density of an image to be printed according to said stored third correction factors.

Claim 24

Independent Claim 133 words

A method of adjusting a recording head, which recording head comprises a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources, the method comprising the steps of: measuring average energy output of each of said sub-sets of recording sources; generating and storing first correction factors derived from said measurements of non-uniformity of energy output of said sub-sets of recording sources; applying, for each sub-set of recording sources, said first correction factors; measuring energy output of each individual one of said recording sources; generating and storing second correction factors derived from measurements of non-uniformity of energy output of each individual one of said recording sources; and applying said second correction factors after applying said first correction factors.

Claim 25

Independent Claim 133 words

A method of adjusting a recording head, which recording head comprises a linear array of recording sources for forming a multi-gradation latent image on a receptor surface, said linear array comprising a plurality of sub-sets of recording sources, the method comprising the steps of: measuring average energy output of each of said sub-sets of recording sources; generating and storing first correction factors derived from said measurements of non-uniformity of energy output of said sub-sets of recording sources; applying, for each sub-set of recording sources, said first correction factors; measuring energy output of each individual one of said recording sources; generating and storing second correction factors derived from measurements of non-uniformity of energy output of each individual one of said recording sources; and applying said second correction factors after applying said first correction factors.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-06-16	2000-12-16	2001-06-17	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-06-16	2004-12-16	2005-06-17	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-06-16	2008-12-16	2009-06-17	$7700.00	Window Closed / Lapsed

Non-impact printer with evenness control

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