US5045420A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color image forming method and particulate developer for developing electrostatic latent image
Assignee: Canon Inc
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Filing: 1989-12-07
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Granted: 1991-09-03
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Expires: 2009-12-07
Abstract
Abstract A color image forming method, comprising the steps of: providing a particulate developer comprising at least two species of sensitive particles which are capable of respectively absorbing lights having different wavelengths to be decolorized or faded; developing an electrostatic latent image with the particulate developer to form an image comprising the developer; and exposing the developer image to light having a wavelength capable of selectively decolorizing at least one species of the sensitive particles.
Inventors
- 👤 Nagao Hosono
- 👤 Shinkichi Takahashi
- 👤 Hatsuo Tajima
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:26
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/09; G03G9/0926; G03G13/00; G03G13/01; G03G13/013
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
71 words
A color image forming method, comprising: providing a particulate developer comprising at least two species of sensitive particles which are capable of respectively absorbing lights having different wavelengths to be decolorized or faded; developing an electrostatic latent image with the particulate developer to form an image comprising the developer; and exposing the developer image to light having a wavelength capable of selectively decolorizing at least one species of the sensitive particles.
Claim 2
Dependent Claim
71 words
A color image forming method, comprising: providing a particulate developer comprising at least two species of sensitive particles which are capable of respectively absorbing lights having different wavelengths to be decolorized or faded; developing an electrostatic latent image with the particulate developer to form an image comprising the developer; and exposing the developer image to light having a wavelength capable of selectively decolorizing at least one species of the sensitive particles.
Claim 3
Dependent Claim
25 words
A method according to claim 1, wherein the electrostatic latent image is formed by charging an electrophotographic photosensitive member and imagewise exposing the photosensitive member.
Claim 4
Dependent Claim
24 words
A method according to claim 2, wherein the photosensitive member is imagewise exposed by means of an optical scanning system using a laser beam.
Claim 5
Dependent Claim
27 words
A method according to claim 1, wherein the sensitive particles are selectively decolorized by three kinds of lights respectively having wavelengths corresponding to red, green and blue.
Claim 6
Dependent Claim
33 words
A method according to claim 1, wherein the timing of the exposure of the light for selectively decolorizing the sensitive particle is determined by detecting the developer image by use of a sensor.
Claim 7
Dependent Claim
27 words
A method according to claim 1, wherein the sensitive particle comprises a semiconductor particle, and a spiropyran metal complex disposed on the surface of the semiconductor particle.
Claim 8
Dependent Claim
32 words
A particulate developer for developing an electrostatic latent image, comprising at least two species of sensitive particles which are capable of respectively absorbing lights having different wavelengths to be decolorized or faded.
Claim 9
Dependent Claim
32 words
A particulate developer for developing an electrostatic latent image, comprising at least two species of sensitive particles which are capable of respectively absorbing lights having different wavelengths to be decolorized or faded.
Claim 10
Dependent Claim
27 words
A developer according to claim 7, wherein the sensitive particle comprises a semiconductor particle, and a spiropyran metal complex disposed on the surface of the semiconductor particle.
Claim 11
Dependent Claim
24 words
A developer according to claim 8, wherein the semiconductor particle comprises a material selected from the group consisting of zinc oxide and titanium oxide.
Claim 12
Dependent Claim
25 words
A developer according to claim 8, wherein the spiropyran metal complex is attached to the surface of the semiconductor particle together with a hydrophilic resin.
Claim 13
Dependent Claim
31 words
A developer according to claim 7, wherein the at least two species of the sensitive particles respectively comprise spiropyran metal complexes having sensitivities to green light, red light and blue light.
Claim 14
Dependent Claim
47 words
A particulate developer for developing an electrostatic latent image comprising: (a) at least two species of sensitive particles which are capable of respectively absorbing light having different wavelengths to be decolorized or faded; and (b) silica fine powder to enhance fluidity and as a charge control agent.
Claim 15
Dependent Claim
47 words
A particulate developer for developing an electrostatic latent image comprising: (a) at least two species of sensitive particles which are capable of respectively absorbing light having different wavelengths to be decolorized or faded; and (b) silica fine powder to enhance fluidity and as a charge control agent.
References Cited (Backward Citations)
US4250239A
Cited
US4725527A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-02 | 1995-03-04 | 1995-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-02 | 1999-03-04 | 1999-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-02 | 2003-03-04 | 2003-09-03 | $7700.00 | Window Closed / Lapsed |