Patent US4538901A successfully refreshed from Google Patents.
US4538901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic copier with a phantom image suppression function
Assignee: Ricoh Co Ltd
•
Filing: 1984-01-19
•
Granted: 1985-09-03
•
Expires: 2004-01-19
Abstract
Abstract An electrophotographic copying machine capable of suppressing the formation of phantom images with a simple structure is provided. The machine includes a pre-transfer exposure lamp for irradiating a toner image formed on an imaging surface and a post-transfer exposure lamp for irradiating the imaging surface after separation of a transfer medium, to which the toner image has been transferred, from the imaging surface. The pre-transfer exposure lamp is provided to ease the transfer of toner image to the transfer medium and the post-transfer exposure lamp is provided to remove residual charge from the imaging surface thereby preparing the imaging surface ready to be used for the next cycle of copy operation. In the present invention, a ratio of light amount of the post-transfer exposure to the light amount of the pre-transfer exposure is maintained within a predetermined range, preferably 30-60%.
Inventors
- 👤 Norimasa Soumiya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:16
CPC Classifications
G; G03; G03G; G03G21/00; G03G21/06; G03G21/08; G03G15/00; G03G15/14; G03G15/16; G03G15/169
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
132 words
An electrophotographic copying machine capable of suppressing the formation of phantom images, comprising: a photosensitive member having an imaging surface; image forming means for forming an electrostatic latent image of an original image on said imaging surface; developing means for developing said latent image thereby converting said latent image into a visible toner image; first irradiating means for irradiating said toner image on said imaging surface with light having a first light amount; transfer means for transferring said toner image thus irradiated by said first irradiating means to a transfer medium from said imaging surface; second irradiating means for irradiating said imaging surface with light having a second light amount; and control means for controlling a light amount ratio between said first and second light amounts to stay within a predetermined range.
Claim 2
Dependent Claim
132 words
An electrophotographic copying machine capable of suppressing the formation of phantom images, comprising: a photosensitive member having an imaging surface; image forming means for forming an electrostatic latent image of an original image on said imaging surface; developing means for developing said latent image thereby converting said latent image into a visible toner image; first irradiating means for irradiating said toner image on said imaging surface with light having a first light amount; transfer means for transferring said toner image thus irradiated by said first irradiating means to a transfer medium from said imaging surface; second irradiating means for irradiating said imaging surface with light having a second light amount; and control means for controlling a light amount ratio between said first and second light amounts to stay within a predetermined range.
Claim 3
Dependent Claim
35 words
The machine of claim 1 wherein said light amount ratio is defined as a ratio of second light amount to first light amount and said ratio is maintained within a range between 30% and 60%.
Claim 4
Dependent Claim
75 words
The machine of claim 2 wherein said control means includes a first light-receiving element disposed to receive light irradiated from said first irradiating means, a second light-receiving element disposed to receive light irradiated from said second irradiating means and a CPU connected to receive signals from said first and second light-receiving elements thereby controlling at least one of said first and second irradiating means to maintain said light amount ratio to be in said range.
Claim 5
Dependent Claim
21 words
The machine of claim 1 wherein said first and second irradiating means are comprised of the same kind of light source.
Claim 6
Dependent Claim
27 words
The machine of claim 4 wherein said light source is selected from a group consisting of a fluorescent lamp, halogen lamp, light emitting diode and cold-cathode tube.
Claim 7
Dependent Claim
26 words
The machine of claim 4 further comprising a common power supply connected to supply a driving power to each of said first and second irradiating means.
Claim 8
Dependent Claim
13 words
The machine of claim 2 wherein said photosensitive member includes a Se-As material.
Claim 9
Dependent Claim
13 words
The machine of claim 2 wherein said photosensitive member includes a Se-Te-Cl material.
Claim 10
Dependent Claim
29 words
The machine of claim 1 wherein said photosensitive member is fixedly attached to the periphery of a drum which is rotatably supported and driven to rotate at constant speed.
Claim 11
Dependent Claim
43 words
The machine of claim 9 wherein said image forming means includes a charging device for charging said imaging surface uniformly to a predetermined polarity and an image exposure device for applying a light image of original to the thus uniformly charged imaging surface.
Claim 12
Dependent Claim
93 words
An electrophotographic copying process, comprising: a step of forming a toner image of an original image on an imaging surface; a step of irradiating said toner image with light having a first light amount; a step of transferring said toner image thus irradiated by the light having a first light amount to a transfer medium; and a step of irradiating said imaging surface with light having a second light amount, characterized by controlling a light amount ratio of said second light amount to said first light amount to stay within a predetermined range.
Claim 13
Dependent Claim
93 words
An electrophotographic copying process, comprising: a step of forming a toner image of an original image on an imaging surface; a step of irradiating said toner image with light having a first light amount; a step of transferring said toner image thus irradiated by the light having a first light amount to a transfer medium; and a step of irradiating said imaging surface with light having a second light amount, characterized by controlling a light amount ratio of said second light amount to said first light amount to stay within a predetermined range.
Claim 14
Dependent Claim
13 words
The process of claim 11 wherein said range is between 30 and 60%.
Claim 15
Dependent Claim
64 words
The process of claim 12 wherein said step of forming a toner image includes uniformly charging said imaging surface, applying a light image of original to said thus uniformly charged imaging surface thereby selectively dissipating the uniform charge to form an electrostatic latent image and developing said latent image thereby converting said latent image into said toner image which is visible to human eyes.
Claim 16
Dependent Claim
27 words
The process of claim 13 further comprising a step of separating said transfer medium from said imaging surface after transfer of said image to said transfer medium.
Claim 17
Dependent Claim
27 words
The process of claim 14 further comprising a step of removing residual toner from said imaging surface after separation of said transfer medium from said imaging surface.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |