Method of manufacturing image forming apparatus

• US 6,822,397 B2
• Filed: 05/06/2003
• Issued: 11/23/2004
• Est. Priority Date: 05/08/2002
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamano, Akihiko, Kawasaki, Hideshi, Aoki, Shuji, Sakata, Hisashi, Tabata, Izumi
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US10/429,683
• Publication Number:
  US 20040034487A1
• Time in Patent Office: 567 Days
• Field of Search: 315/169--16, 445/3, 445/24, 445/51, 345/55, 345/75.2, 345/48, 345/56
• US Class Current: 315/169.2
• CPC Class Codes: G09G 2320/0285 using tables for spatial correction of display data
• CPC Class Codes: G09G 2320/0693 Calibration of display systems
• CPC Class Codes: G09G 3/006 Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309
• CPC Class Codes: G09G 3/22 using controlled light sources

Abstract

The present invention relates to the adjustment of luminance. The present invention is a method of manufacturing image forming apparatus including a step of applying characteristic shift voltage comprising a plurality of pulses in which the amplitude of the pulse obtained from the look-up table has two or more values, to the emitter, the look-up table storing the amplitude of the pulse and the number of the pulse for shifting characteristic of emitters to a predetermined luminance target value on the basis of the measurement result of the luminance. Moreover, the present invention is a method of manufacturing image forming apparatus comprising a step of applying the second pulses of characteristic shift voltage having the amplitude which was determined in response to the measurement result of the luminance after the first characteristic shift voltage had been applied to the emitter.

Claims

1. A method for manufacturing an image forming apparatus having a multiple electron source in which a plurality of emitters are disposed on a substrate and fluorescent materials for emitting light by irradiation of electron beam from the multiple electron source, comprising:

a first measurement step of measuring change of luminance, when a pulse having a plurality of amplitude larger than drive voltage is applied to the predetermined number of the emitters, with respect to the amplitude of the pulse and the number of the pulse;

a step of preparing, on the basis of the measurement result of the first measurement step, a look-up table for storing the amplitude of the pulse and the number of the pulse for shifting characteristic of emitters to a predetermined luminance target value;

a second measurement step of measuring the luminance when the drive voltage is applied to the emitter; and

a step of applying, on the basis of the measurement result of the second measurement step, characteristic shift voltage comprising a plurality of pulses in which the amplitude of the pulse obtained from the look-up table has two or more values, to the emitter.

2. A method for manufacturing the image forming apparatus according to claim 1, wherein the characteristic shift voltage comprises first pulses and second pulses, and after the first pulses are applied to the emitter, the second measurement step is carried out again, and the second pulses having the amplitude which was determined in response to the measurement result of the second measurement step is applied.

3. A method for manufacturing an image forming apparatus having a multiple electron source in which a plurality of emitters are disposed on a substrate and fluorescent materials for emitting light by irradiation of electron beam from the multiple electron source, comprising:

a first measurement step of measuring change of luminance, when a pulse having a plurality of amplitude larger than drive voltage is applied to the predetermined number of the emitters, to the amplitude of the pulse and the number of the pulse;

a step of preparing, on the basis of the measurement result of the first measurement step, a look-up table for storing the amplitude of the pulse and the number of the pulse for shifting characteristic of emitters to a predetermined luminance target value;

a second measurement step of measuring the luminance when the drive voltage is applied to the emitter; and

a step of applying, on the basis of the measurement result of the second measurement step, characteristic shift voltage comprising a plurality of pulses in which pulse width of the pulse obtained from the look-up table has two or more values, to the emitter.

4. A method for manufacturing the image forming apparatus according to claim 3, wherein the characteristic shift voltage comprises first pulses and second pulses, and after the first pulses are applied to the emitter, the second measurement step is carried out again, and the second pulses having the amplitude which was determined in response to the measurement result of the second measurement step is applied.

5. A method for manufacturing an image forming apparatus having a multiple electron source in which a plurality of emitters are disposed on a substrate and fluorescent materials for emitting light by irradiation of electron beam from the multiple electron source, comprising:

a step of measuring change of luminance with respect to each of characteristic shift voltages and preparing a luminance adjustment rate table, when a plurality of characteristic shift voltages which have different voltage values larger than drive voltage are applied to the predetermined number of the emitters;

a step of measuring luminance to set luminance target value L0 and obtaining maximum luminance Lmax, when the drive voltage is applied to the emitter;

a step of determining maximum adjustment shift voltage and a group of the adjustment shift voltage with smaller voltage values than the maximum adjustment shift voltage, by referring to the luminance adjustment rate table with maximum adjustment rate Dmax of luminance of Dmax=L0/Lmax, and

a step of applying the adjustment shift voltage selected from the adjustment shift voltage group to the emitter.

6. A method for manufacturing the image forming apparatus according to claim 5, wherein the group of the adjustment shift voltages comprises n pieces of adjustment shift voltages which satisfy a formula of n≧

(Lmax−

L0)/Δ

L (provided, Δ

L means variation acceptable scope of the luminance from the luminance target value L0), and the adjustment shift voltage is determined with reference to the luminance adjustment rate table from adjustment rate Ds satisfying a formula of Ds=1−

((Dmax)m/n)[m=1 . . . n−

1].