EP0686993A1
Expired / Lapsed
EP
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Electron-beam generating device having plurality of cold cathode elements, method of driving said device and image forming apparatus applying same
Assignee: Canon Inc
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Filing: 1995-06-07
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Granted: —
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Expires: 2015-06-07
Abstract
Abstract An electron-beam generating device, in which a number of cold cathode elements are matrix-wired, as well as a method of driving the device, is applied to an image forming apparatus. Statistical calculations are performed in advance with regard to a required electron-beam output, and loss produced in the matrix wiring is analyzed. Drive signals are corrected by deciding optimum correction values based upon the analytical results. As a result, when rows of the matrix are driven successively row by row, the intensity of the outputted electron beams can made accurate for any driving pattern.
Inventors
- 👤 Noritake Suzuki
- 👤 Hidetoshi Suzuki
- 👤 Akira Asai
- 👤 Akihiko Yamano
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 17:51
CPC Classifications
G; G09; G09G; G09G1/00; G09G3/00; G09G3/20; G09G3/22; H; H01; H01J; H01J31/00; H01J31/08; H01J31/10; H01J31/12; H01J31/123; H01J31/125; H01J31/127; G09G2320/00; G09G2320/02; G09G2320/0209; G09G2320/0223; H01J2201/00; H01J2201/30; H01J2201/316; H01J2201/3165
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
147 words
An electron-beam generating device characterized by comprising: a plurality of cold cathode elements (1002) arrayed in the form of rows and columns on a substrate; m-number of row wires and n-number of column wires (1004) for wiring said plurality of cold cathode elements into a matrix; and drive signal generating means (2101) for generating signals which drive said plurality of cold cathode elements; wherein said drive signal generating means including: statistic calculating means (206) for performing a statistical calculation with regard to the externally entered electron-beam demand values (5000); correction-value generating means (207) for generating correction values on the basis of results of calculation by said statistic calculating means; combining means (208) for combining the externally entered electron-beam demand values and the correction values; and means (202, 209) for successively driving the matrix-wired cold cathode elements on the basis of an output value from said combining means.
Claim 2
Dependent Claim
35 words
The apparatus according to claim 1, wherein said statistic calculating means includes means (206) for calculating a sum total of one row of electron-beam demand values with regard to the externally entered electron-beam demand values.
Claim 3
Dependent Claim
80 words
The apparatus according to claim 1, wherein said correction-value generating means includes means (1801) for calculating a current, which will flow into the row wires and column wires at the time of drive, on the basis of results of calculation by said statistic calculating means and output characteristic of the cold cathode elements, analyzing amount of electrical loss due to wiring resistance (1804, 1805), deciding amount of correction for compensating for the loss and outputting the amount of correction (1807).
Claim 4
Dependent Claim
40 words
The apparatus according to claim 1, wherein said correction-value generating means includes a look-up table (207) which stores correction values predetermined with regard to all cases of results of calculation capable of being outputted by said statistic-quantity calculating means (206).
Claim 5
Dependent Claim
92 words
The apparatus according to claim 4, wherein the correction values stored in said look-up table (207) in advance are correction quantities obtained by calculating a current, which will flow into the row wires and column wires at the time of drive, on the basis of output characteristics of the cold cathode elements with regard to all cases of results of calculation capable of being outputted by said statistic-quantity calculating means, analyzing beforehand amount of electrical loss due to wiring resistance, and determining the correction quantities in advance based upon results of analysis.
Claim 6
Dependent Claim
156 words
The apparatus according to claim 1, wherein said correction-value generating means comprises means for outputting correction quantities V1 ∼ Vn calculated in accordance with the following equation (1801∼1807): where the parameters are as follows: V1 ∼ Vn: correction quantities for cold cathode elements of columns 1 ∼ n in j-th row; I1 ∼ In: current values, to be passed through column wires of columns 1 ∼ n, calculated based upon externally entered electron-beam demand values and electron emission characteristics of cold cathode elements; Ra: electrical resistance of extracted portion of row wiring; I1+I2+ ... +In: sum total of one row of externally entered electron-beam demand values (namely results of calculation by said statistic calculating means); Rb: electrical resistance of extracted portion of column wiring; ry: electrical resistance between cold cathode elements of column wiring; rx: electrical resistance between cold cathode elements of row wiring; n: total number of columns of matrix; and j: row number (1≦j≦m).
Claim 7
Dependent Claim
23 words
The apparatus according to claim 6, wherein said correction-value generating means includes a first-in last-out circuit (1902) and an adder circuit (1901, 1903).
Claim 8
Dependent Claim
30 words
The apparatus according to claim 1, wherein said combining means (1705) adds or multiplies together the externally entered electron-beam demand values and correction values generated by said correction-value generating means.
Claim 9
Dependent Claim
18 words
The apparatus according to claim 1, wherein image information is used as the externally entered electron-beam demand values.
Claim 10
Dependent Claim
17 words
The apparatus according to claim 1, wherein said cold cathode elements are surface-conduction electron emission elements (1002).
Claim 11
Dependent Claim
36 words
An image forming apparatus comprising the electron-beam generating device of claims 1 to 10 and an image forming member (1008) for forming an image by irradiation with an electron beam outputted by said electron-beam generating device.
Claim 12
Dependent Claim
15 words
The apparatus according to claim 11, wherein said image forming member is a phosphor (1008).
Claim 13
Independent Claim
156 words
A method of driving an electron-beam generating device, which has: a plurality of cold cathode elements (1002) arrayed in the form of rows and columns on a substrate, and m-number of row wires and n-number of column wires (1004) for wiring said plurality of cold cathode elements into a matrix, characterized by comprising: drive signal generating step (2101) of generating signals which drive said plurality of cold cathode elements; wherein said drive signal generating step including: a statistic calculating step (206) of performing a statistical calculation with regard to the externally entered electron-beam demand values (5000); a correction-value generating step (207) of generating correction values on the basis of results of calculation by said statistic calculating step; a combining step (208) of combining the externally entered electron-beam demand values and the correction values; and steps (202, 209) of successively driving the matrix-wired cold cathode elements on the basis of an output value from said combining step.
Claim 14
Dependent Claim
36 words
The method according to claim 13, wherein said statistic calculating step includes a step (206) of calculating a sum total of one row of electron-beam demand values with regard to the externally entered electron-beam demand values.
Claim 15
Dependent Claim
81 words
The method according to claim 13, wherein said correction-value generating step includes a step (1801) of calculating a current, which will flow into the row wires and column wires at the time of drive, on the basis of results of calculation by said statistic calculating step and output characteristic of the cold cathode elements, analyzing amount of electrical loss due to wiring resistance (1804, 1805), deciding amount of correction for compensating for the loss and outputting the amount of correction (1807).
Claim 16
Dependent Claim
40 words
The method according to claim 13, wherein said correction-value generating step includes a look-up table (207) which stores correction values predetermined with regard to all cases of results of calculation capable of being outputted by said statistic-quantity calculating step (206).
Claim 17
Dependent Claim
92 words
The method according to claim 16, wherein the correction quantities stored in said look-up table (207) in advance are correction values obtained by calculating a current, which will flow into the row wires and column wires at the time of drive, on the basis of output characteristics of the cold cathode elements with regard to all cases of results of calculation capable of being outputted by said statistic-quantity calculating step, analyzing beforehand amount of electrical loss due to wiring resistance, and determining the correction quantities in advance based upon results of analysis.
Claim 18
Dependent Claim
157 words
The method according to claim 13, wherein said correction-value generating step comprises a step of outputting correction quantities V1 ∼ Vn calculated in accordance with the following equation (1801∼1807): where the parameters are as follows: V1 ∼ Vn: correction quantities for cold cathode elements of columns 1 ∼ n in j-th row; I1 ∼ In: current values, to be passed through column wires of columns 1 ∼ n, calculated based upon externally entered electron-beam demand values and electron emission characteristics of cold cathode elements; Ra: electrical resistance of extracted portion of row wiring; I1+I2+ ... +In: sum total of one row of externally entered electron-beam demand values (namely results of calculation by said statistic calculating means); Rb: electrical resistance of extracted portion of column wiring; ry: electrical resistance between cold cathode elements of column wiring; rx: electrical resistance between cold cathode elements of row wiring; n: total number of columns of matrix; and j: row number (1≦j≦m).
Claim 19
Dependent Claim
30 words
The method according to claim 13, wherein said combining step (1705) adds or multiplies together the externally entered electron-beam demand values and correction values generated by said correction-value generating step.
Claim 20
Dependent Claim
19 words
The method according to claim 13, wherein image information is used as the externally entered electron beam demand values.
Claim 21
Dependent Claim
17 words
The method according to claim 13, wherein said cold cathode elements are surface-conduction electron emission elements (1002).
Claim 22
Dependent Claim
46 words
An image forming method comprising the step of driving an electron beam generating device of claim 13 to 21 and an image forming step (1008) for forming an image by irradiation with an electron beam outputted by said step of driving the electron beam generating device.
Claim 23
Independent Claim
54 words
A device comprising: an array of electron emissive elements, and a matrix addressing system for applying drive signals to chosen electron emissive elements within the array, the device further comprising means for adjusting the drive signal applied to any particular element dependent on signals being applied to other electron emissive elements within the array.
Claim 24
Independent Claim
44 words
A method of driving an array of electron emissive elements connected to a matrix addressing system including the step of adjusting the drive signals applied to any particular electron emissive element dependent on signals being applied to other electron emissive elements within the array.
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