EP0851312A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Color-image forming apparatus for printing a color image
Assignee: Fujifilm Business Innovation Corp
•
Filing: 1997-12-19
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Granted: —
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Expires: 2017-12-19
Abstract
Abstract An electrophotographic printer apparatus for printing a color image is provided with a receptive layer for recording an electrostatic latent image and a developer unit for applying the toners of a number of colors to the electrostatic latent image. Also provided are an intermediate transfer medium to which toner images formed in a layered form on the receptive layer are transferred, and a power supply for applying a difference in potential between the intermediate transfer medium and the receptive layer. Further provided are a current detector for detecting a value of an electric current flowing across the intermediate transfer medium and the receptive layer, and a transfer unit for transferring the toner image formed on the intermediate transfer medium to a recording medium. Furthermore, a main controller is provided for effecting control in setting the potential difference between the intermediate transfer medium and the receptive layer to V1, in obtaining a current value I1 from the current detector when a toner layer is not present between the intermediate transfer medium and the receptive layer, in obtaining a current value IX from the current detector when the toner layer is present between the intermediate transfer medium and the receptive layer, and in optimally correcting operating conditions of an image-forming element by determining characteristics of the toner layer on the basis of a difference between the current value I1 and the current value IX.
Inventors
- 👤 Chiseki Yamaguchi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 06:54
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/50; G03G15/5054; G03G15/01; G03G15/0105; G03G15/0131; G03G15/0142; G03G15/0147; G03G15/0152; G03G15/0173; G03G15/0178; G03G15/5033; G03G15/5041; H; H04; H04N; H04N1/00; H04N1/23; H04N1/29; H04N1/295; G03G15/0189; G03G2215/00; G03G2215/00025; G03G2215/00029; G03G2215/00059; G03G2215/00063; G03G2215/01; G03G2215/0103; G03G2215/0119; G03G2215/0167; G03G2215/0174; G03G2215/018
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
237 words
A color image forming apparatus for printing a color image,
comprising: a receptive layer (4) for recording an electrostatic latent
image; a developer unit (Y,M,C,K) for applying toners of a number
of colors to the electrostatic latent images;
an intermediate transfer medium (3) being transferred the
layered toner images formed on the receptive layer (4); a power supply (1) for applying a difference in potential
between the intermediate transfer medium (3) and the receptive
layer (4); a current detector (2) for detecting a value of an electric
current flowing across the intermediate transfer medium (3) and
the receptive layer (4); a transfer unit (5) for transferring the toner image formed
on the intermediate transfer medium (3) to a recording medium; and a main controller (6) including following functions: (i) setting the potential difference between the
intermediate transfer medium (3) and the receptive layer (4) to
V1; (ii) obtaining a current value I1 from the current detector
(2) when a toner layer is not present between the intermediate
transfer medium (3) and the receptive layer (4); (iii) obtaining a current value IX from the current
detector (2) when the toner layer is present between the
intermediate transfer medium (3) and the receptive layer (4);
and (iv) optimally correcting operating conditions of an
image-forming element (13,15,Y,M,C,K) by determining
characteristics of the toner layer on the basis of a difference
between the current value I1 and the current value IX.
Claim 2
Dependent Claim
30 words
An electrophotographic printer apparatus according to claim
1, wherein the power supply (1) applies the voltage V1 to the
intermediate transfer medium (3), and the receptive layer (4)
is grounded.
Claim 3
Dependent Claim
23 words
An apparatus according to claim 1 or
2, wherein the current detector (2) detects the current flowing
across the intermediate transfer medium (3).
Claim 4
Dependent Claim
43 words
An apparatus according to claim 1, 2 or
3, wherein the main controller (6) causes the transfer unit (5)
to be spaced apart from the intermediate transfer medium (3) when
the current values I1 and IX are obtained from the current detector
(2).
Claim 5
Independent Claim
148 words
An apparatus according to any one of claims 1 to 4,
wherein the main controller (6) including following functions: (i) forming on the receptive layer (4) of a toner image of
a test pattern for each color of Y, M, C, and K; (ii) obtaining current values IY, IM, IC, and IK from the
current detector (2) for the test patterns of the respective
colors as the current values IX each time the toner images of
the test patterns of the respective colors are consecutively
brought into a nip between the receptive layer (4) and the
intermediate transfer medium (3); ansssssd (iii) optimally correcting the operating conditions of the
image-forming element (13,15,Y,M,C,K) by individually
determining the characteristics of the toner layers of the
respective colors on the basis of the respective differences
between the current value I1 and each of the current values IY,
IM, IC, and IK.
Claim 6
Independent Claim
44 words
An apparatus according to any one of claims 1 to
5, wherein the toner image of the test pattern is equal to or
larger than a region where the receptive layer (4) and the
intermediate transfer medium (3) come into contact with each
other.
Claim 7
Independent Claim
60 words
An apparatus according to any one of claims 1 to 6, wherein the receptive layer (4) has a charging unit (15) for
charging a surface of the receptive layer (4) and a light source
(13) for forming the electrostatic latent image, and the main
controller (6) controls the power of the light source (13) for
optimally correcting the operating conditions.
Claim 8
Independent Claim
33 words
An apparatus according to any one of claims 1 to 7, wherein the main controller (6) optimally corrects the
operating conditions by controlling an amount of toner supplied
by the developer unit (Y,M,C,K).
Claim 9
Independent Claim
71 words
An apparatus according to any one of claims 1 to 8, wherein the main controller (6) maintaining default operating
conditions if the difference between the current value I1 and
the current value IX is within a prescribed range set in advance;
wherein the main controller (6) optimally correcting the
operating conditions if the difference between the current value
I1 and the current value IX exceeds the prescribed range set in
advance.
Claim 10
Dependent Claim
195 words
An electrophotographic printer apparatus for printing a
color image, comprising: a receptive layer (19) for recording an electrostatic latent
image; a developer unit (Y,M,C,K) for applying toners of a number
of colors to the electrostatic latent image; an intermediate transfer medium (3A) being transferred
toner images formed on the receptive layer (19); a transfer unit (5) for transferring the toner image formed
on the intermediate transfer medium (3A) to a recording medium; a first power supply (1) for applying a difference in
potential between the intermediate transfer medium (3A) and the
transfer unit (5); a current detector (2) for detecting a value of an electric
current flowing across the intermediate transfer medium (3A) and
the transfer unit (5); and a main controller (6) for obtaining a current value ΔI2 of
the current flowing across the intermediate transfer medium (3A)
and the transfer unit (5) on the basis of an output of the current
detector (2), and the main controller (6) optimally correcting
the potential difference between the intermediate transfer
medium (3A) and the transfer unit (5) on the basis of a difference
between the current value ΔI2 and an ideal value IB set in advance.
Claim 11
Dependent Claim
31 words
An electrophotographic printer apparatus according to claim
10, wherein the first power supply (1) applies a voltage V1 to
the intermediate transfer medium (3A), and the receptive layer
(19) is grounded.
Claim 12
Dependent Claim
94 words
An apparatus according to claim 10 or 11, wherein the current detector (2) detects a value of the current
flowing across the intermediate transfer medium (3A), and wherein the main controller (6) including following functions: (i) obtaining from the current detector (2) a current value
I1 when the transfer unit (5) is being spaced apart from the
intermediate transfer medium (3A); (ii) obtaining from the current detector (2) a current value
I2 when the transfer unit (5) is in contact with the intermediate
transfer medium (3A), and (iii) calculating ΔI2 from I2 - I1.
Claim 13
Dependent Claim
95 words
An apparatus according to claim 10, 11 or 12, wherein the main controller (6) including following
functions: (i) setting the potential difference between the intermediate
transfer medium (3A) and the transfer unit (5) to a default value
if the difference between the current value ΔI2 and the ideal
value IB is within a prescribed range set in advance; (ii) optimally correcting the potential difference between the
intermediate transfer medium (3A) and the transfer unit (5) if
the difference between the current value ΔI2 and the ideal value
IB exceeds the prescribed range set in advance.
Claim 14
Dependent Claim
97 words
An apparatus according to claim 10, 11, 12 or 13, wherein the transfer unit (5) having a connection switcher
for selectively connecting the transfer unit (5) to a second power
supply (17) or to a ground, and the main controller (6) including following functions: (i) connecting the transfer unit (5) to the ground for
correcting the potential difference between the intermediate
transfer medium (3A) and the transfer unit (5); and (ii) connecting the transfer unit (5) to the second power supply
(17) for transferring the toner image from the intermediate
transfer medium (3A) to a recording medium.
Claim 15
Independent Claim
43 words
An apparatus according to any one of claims 10 to 14, wherein the main controller (6) changes the voltage
to be applied to the transfer unit (5) for correcting the potential
difference between the intermediate transfer medium (3A) and the
transfer unit (5).
Claim 16
Dependent Claim
238 words
An electrophotographic printer apparatus for printing a
color image, comprising: a receptive layer (4) for recording an electrostatic latent
image; a developer unit (Y,M,C,K) for applying toners of a number
of colors to the electrostatic latent image; an intermediate transfer medium (3) being transferred toner
images formed on the receptive layer (4); a transfer unit (5) for transferring the toner image formed
on the intermediate transfer medium (3) to a recording medium; a first power supply (1) for applying a difference in
potential between the intermediate transfer medium (3) and the
transfer unit (5); a second power supply (17) for allowing an electric current
to flow across a pair of electrodes disposed on both sides of
a transport passage for the recording medium; a current detector (27) for detecting the current flowing
across the pair of electrodes (28); and a main controller (6) including following functions: (i) obtaining from the current detector (27) the current when
the recording medium is not present between the pair of electrodes
(28); (ii) obtaining from the current detector (27) the current when
the recording medium is present between the pair of electrodes
(28); and (iii) optimally correcting the potential difference between
the intermediate transfer medium (3) and the transfer unit (4)
on the basis of a difference between the current when the recording
medium is not present and the current when the recording medium
is present between the pair of electrodes (28).
Claim 17
Dependent Claim
29 words
An electrophotographic printer apparatus according to claim
16, wherein the second power supply (17) also serves as a power
supply for applying the voltage to the transfer unit (5).
Claim 18
Dependent Claim
124 words
An apparatus according to claim 16 or 17, wherein the main controller (6) including following
functions: (i) setting the potential difference between the intermediate
transfer medium (3) and the transfer unit (5) to a default value
if the difference of two current value is within a prescribed
range set in advance, wherein one current value relates when
recording medium is not present, other current value relates when
the recording medium is present; (ii) optimally correcting the potential difference between
the intermediate transfer medium (3) and the transfer unit (5)
if the difference of two current value exceeds the prescribed
range set in advance, wherein one current value relates when
recording medium is not present, other current value relates when
the recording medium is present;
Claim 19
Dependent Claim
40 words
An apparatus according to claim 16, 17 or 18, wherein the main controller (6) changes the voltage to be
applied to the transfer unit for correcting the potential
difference between the intermediate transfer medium (3) and the
transfer unit (5).
Claim 20
Independent Claim
34 words
An apparatus according to any one of claims 16 to 19, wherein the pair of electrodes disposed on both sides
of the transport passage for the recording medium is a pair of
rollers (28).
References Cited (Backward Citations)
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