| CPC G03G 5/047 (2013.01) [G03G 5/144 (2013.01); G03G 21/1814 (2013.01)] | 7 Claims |
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1. An electrophotographic photosensitive member comprising in this order:
a support;
an undercoat layer comprising titanium oxide particles whose surfaces are treated with an organosilicon compound, which exhibit a degree of hydrophobicity of 10 to 70%;
a charge-generating layer; and
a charge-transporting layer, wherein
with regard to an S0, an S1, an S2, an S3, and an S4 determined by
the following procedure (A),
a ratio S1/S0 is 0.34 or less, and
one of the S2, the S3, or the S4 is a positive value, and another two thereof are negative values, or two thereof are positive values, and another one thereof is a negative value:
procedure (A)
A1. a temperature of 15° C. is represented by T1 [° C.] and a relative humidity of 45% RH is represented by Φ1 [% RH], and a Vexp [V] corresponding to each Iexp [μJ/cm2] is obtained at the temperature T1 [° C.] and the relative humidity Φ1 [% RH] by the following procedure (B);
procedure (B)
the following B1 to B5 are performed while the electrophotographic photosensitive member is rotated at a rotational speed of 60 rpm:
B1. a surface potential is set to 0;
B2. a voltage is applied to a surface of the electrophotographic photosensitive member so that an absolute value of the surface potential becomes 500 V;
B3. exposure is performed with light having a wavelength of 655 nm and a light amunt Iexp [μJ/cm2] 0.125 second after completion of the voltage application;
B4. the absolute value of the surface potential obtained through measurement 0.250 second after the completion of the voltage application is represented by Vexp [V]; and
B5. while the Iexp is changed from 0.000 μJ/cm2 to 1.000 μJ/cm2 at intervals of 0.001 μJ/cm2, the B1 to the B4 are repeatedly performed to provide the Vexp [V] corresponding to each Iexp [μJ/cm2];
A2. a temperature of 45° C. is represented by T2 [° C.] and a relative humidity of 16% RH is represented by Φ2 [% RH], and the Vexp [V] corresponding to each Iexp [μJ/cm2] is obtained at the temperature T2 [° C.] and the relative humidity Φ2 [% RH] by the procedure (B);
A3. the Vexp [V] obtained in the A1 is plotted to produce a graph whose axis of ordinate and axis of abscissa indicate the Vexp [V] and the Iexp, respectively, and a slope “k” in a range of the Iexp of from 0.000 to 0.030 μJ/cm2 is determined, followed by determination of quantum efficiency η0 (T1, Φ1) from the following equation (1):
 in the equation (1), “e” represents an elementary charge, “d” represents a thickness of a photosensitive layer, η0 represents quantum efficiency, ε0 represents a dielectric constant of vacuum, εr represents a relative dielectric constant of the charge-transporting layer, “h” represents the Planck constant, and v represents a frequency of the applied light;
A4. a recombination constant Pe (T1, Φ1) and a residual voltage Vr (T1, Φ1) at the temperature T1 [° C.] and the relative humidity Φ1 [% RH] are determined by subjecting the graph produced in the A3 to fitting through use of the following equation (2) where the value of the quantum efficiency no determined in the A3 is used at a time of the fitting, thereby a relationship between the Vexp [V] (T1, Φ1) and the Iexp [μJ/cm2] under conditions of the temperature T1 [° C.] and the relative humidity Φ1 [% RH], a relationship according to the following equation (2), is obtained:
 in the equation (2), Vr represents residual voltage, Vd represents the absolute value of the surface potential before the exposure, Pe represents a recombination constant, “e” represents the elementary charge, “d” represents the thickness of the photosensitive layer, η0 represents the quantum efficiency, ε0 represents the dielectric constant of vacuum, εr represents the relative dielectric constant of the charge-transporting layer, “h” represents the Planck constant, and v represents the frequency of the applied light;
A5. quantum efficiency η0 (T2, Φ2), a recombination constant Pe (T2, Φ2), and a residual voltage Vr (T2, Φ2) at the temperature T2 [° C.] and the relative humidity Φ2 [% RH] are determined for the Vexp [V] obtained in the A2 in the same manner as in the A3 and the A4, thereby a relationship between the Vexp [V] (T2, Φ2) and the Iexp [μJ/cm2] under conditions of the temperature T2 [° C.] and the relative humidity Φ2 [% RH], the relationship according to the equation (2), is obtained;
A6. a value obtained by subtracting the Vexp [V] (T2, Φ2) from the Vexp [V] (T1, Φ1) is represented by ΔVexp [V];
A7. with regard to the Vexp [V] obtained in the A1, the light amount when Vexp [V]=250 V is represented by I1/2 [μJ/cm2], and the Vexp [V] when Iexp [μJ/cm2]=3.414·I1/2 [μJ/cm2] is represented by VR [V], and at this time, an integrated value of a |ΔVexp| [V] when the Vexp [V] (T1, Φ1) falls within a range of from the VR [V] to 500 V in a relationship between the |ΔVexp| [V] and the Vexp [V] (T1, Φ1) is represented by S0;
A8. a relationship between the Iexp [μJ/cm2] and the Vexp [V] is obtained by using the equation (2) with the values of the quantum efficiency η0 (T1, Φ1), the recombination constant Pe (T1, Φ1), and the residual voltage Vr (T2, Φ2);
A9. a value obtained by subtracting the Vexp [V] obtained in the A8 from the Vexp [V] (T1, Φ1) is represented by ΔVa [V];
A10. an integrated value of a |ΔVa| [V] when the Vexp [V] (T1, Φ1) falls within the range of from the VR [V] to 500 V in a relationship between the |ΔVa| [V] and the Vexp [V] (T1, Φ1) is represented by S1, and an integrated value of the ΔVa [V] when the Vexp [V] (T1, Φ1) falls within the range of from the VR [V] to 500 V in a relationship between the ΔVa [V] and the Vexp [V] (T1, Φ1) is represented by S2;
A11. the relationship between the Iexp [μJ/cm2] and the Vexp [V] is obtained by using the equation (2) with the values of the quantum efficiency η0 (T2, Φ2), the recombination constant Pe (T1, Φ1), and the residual voltage Vr (T1, Φ1);
A12. a value obtained by subtracting the Vexp [V] obtained in the A11 from the Vexp [V] (T1, Φ1) is represented by ΔVb [V];
A13. an integrated value of the ΔVb [V] when the Vexp [V] (T1, Φ1) falls within the range of from the VR [V] to 500 V in a relationship between the ΔVb [V] and the Vexp [V] (T1, Φ1) is represented by S3;
A14. the relationship between the Iexp [μJ/cm2] and the Vexp [V] is obtained by using the equation (2) with the values of the quantum efficiency η0 (T1, Φ1), the recombination constant Pe (T2, Φ2), and the residual voltage Vr (T1, Φ1);
A15. a value obtained by subtracting the Vexp [V] obtained in the A14 from the Vexp [V] (T1, Φ1) is represented by ΔVc [V]; and
A16. an integrated value of the ΔVc [V] when the Vexp [V] (T1, Φ1) falls within the range of from the VR [V] to 500 V in a relationship between the ΔVc [V] and the Vexp [V] (T1, Φ1) is represented by S4.
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