An electrophotographic photosensitive member (1) includes a conductive substrate (2) and a photosensitive layer (3). The photosensitive layer (3) is a single-layer photosensitive layer. The photosensitive layer (3) contains at least a charge generating material, a hole transport material, an electron transport material, and a binder resin. The charge generating material includes a metal-free phthalocyanine. The hole transport material includes a triphenylamine derivative represented by general formula (1) shown below. The electron transport material includes a quinone derivative represented by general formula (2) shown below. In general formula (1), R.sup.1 R.sup.2, R.sup.3, m1, m2, k, p, and q are the same as those described in the description. In general formula (2), R.sup.4, R.sup.5, and R.sup.6 are the same as those described in the description.

##STR00001##

An electrophotographic photoreceptor includes a conductive substrate, an undercoat layer on the conductive substrate, and a photosensitive layer on the undercoat layer. The undercoat layer contains at least one perinone compound selected from the group consisting of a compound represented by general formula (1) below and a compound represented by general formula (2) below, an amine compound (A) having an ionization potential of 5.4 eV or more and 5.9 eV or less, and a binder resin, ##STR00001##
where: in general formula (1), R.sup.11, R.sup.12, R.sup.13, R.sup.14, R.sup.15, R.sup.16, R.sup.17, and R.sup.18 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group, or a halogen atom; R.sup.11 and R.sup.12 may be bonded to each other to form a ring, so may R.sup.12 and R.sup.13, and so may R.sup.13 and R.sup.14; and R.sup.15 and R.sup.16 may be bonded to each other to form a ring, so may R.sup.16 and R.sup.17, and so may R.sup.17 and R.sup.18, and in general formula (2), R.sup.21, R.sup.22, R.sup.23, R.sup.24, R.sup.25, R.sup.26, R.sup.27, and R.sup.28 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aralkyl group, an aryl group, an aryloxy group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkoxycarbonylalkyl group, an aryloxycarbonylalkyl group, or a halogen atom; R.sup.21 and R.sup.22 may be bonded to each other to form a ring, so may R.sup.22 and R.sup.23, and so may R.sup.23 and R.sup.24; and R.sup.25 and R.sup.26 may be bonded to each other to form a ring, so may R.sup.26 and R.sup.27, and so may R.sup.27 and R.sup.28.

The present disclosure provides an electrophotographic photosensitive member that can suppress a black spot and an exposure memory. The electrophotographic photosensitive member has a support, an undercoat layer and a photosensitive layer having a mono-layer structure in this order, wherein the undercoat layer contains a binder resin and strontium titanate particles; and the photosensitive layer having a mono-layer structure contains a binder resin, a charge generation material, a hole transport material and an electron transport material.

An image forming apparatus includes an image bearing member, a charger, and a cleaning member. The charger charges a circumferential surface of the image bearing member to a positive polarity. The cleaning member is pressed against the circumferential surface of the image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. A linear pressure N of the cleaning member on the circumferential surface of the image bearing member is at least 14 N/m and no greater than 40 N/m. A rebound resilience R of the cleaning member at a temperature of 25 C. is at least 38%. The leaner pressure N and the rebound resilience R satisfy mathematical formula (1A). The image bearing member satisfies mathematical formula (1B). $\begin{array}{cc}R<13.771N^{0.4043}& \left(1A\right)\\ 0.60\frac{V}{\left(Q/S\right)\left(d/{\mathrm{.Math.}}_r.Math.{\mathrm{.Math.}}_0\right)}& \left(1B\right)\end{array}$

An image forming apparatus includes an image bearing member and a static elimination device. The static elimination device irradiates static elimination light onto a circumferential surface of the image bearing member. The image bearing member includes a conductive substrate and a single-layer photosensitive layer. The photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The static elimination light has a wavelength of at least 600 nm and no greater than 800 nm. The photosensitive layer has an optical absorption coefficient of at least 600 cm.sup.1 and no greater than 1,500 cm.sup.1 with respect to light having a wavelength of 660 nm.

In an image forming apparatus, a cleaning member is pressed against a circumferential surface of an image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. The toner has a number average roundness of 0.965 to 0.998. The toner has a D.sub.50 of 4.0 m to 7.0 m. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is 10 N/m to 40 N/m. The image bearing member includes a single-layer photosensitive layer containing a charge generating material and a hole transport material. Ionization potential Ip.sub.HTM of the hole transport material and ionization potential Ip.sub.CGM of the charge generating material satisfy mathematical formula (1) Ip.sub.HTM5.30 eV, mathematical formula (2) Ip.sub.CGM5.30 eV, and mathematical formula (3) 0.09 eV|Ip.sub.HTMIp.sub.CGM|0.30 eV.

An image forming apparatus includes an image bearing member, a charger, and a cleaning member. The charger charges a circumferential surface of the image bearing member to a positive polarity. The cleaning member is pressed against the circumferential surface of the image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. A linear pressure of the cleaning member on the circumferential surface of the image bearing member is at least 10 N/m and no greater than 40 N/m. The image bearing member includes a conductive substrate and a single-layer photosensitive layer. The single-layer photosensitive layer contains a charge generating material, a hole transport material, an electron transport material, and a binder resin. The image bearing member satisfies formula (1)

[00001]$\begin{array}{cc}0.60\frac{V}{\left(Q/S\right)\left(d/{\mathrm{.Math.}}_r.Math.{\mathrm{.Math.}}_0\right)}.& \left(1\right)\end{array}$

An image forming apparatus includes an image bearing member, a charger, and a cleaning member. The charger charges a circumferential surface of the image bearing member to a positive polarity. The cleaning member is pressed against the circumferential surface of the image bearing member and collects a toner remaining on the circumferential surface of the image bearing member. A linear pressure N of the cleaning member on the circumferential surface of the image bearing member is at least 14 N/m and no greater than 40 N/m. A rebound resilience R of the cleaning member at a temperature of 25 C. is at least 38%. The leaner pressure N and the rebound resilience R satisfy mathematical formula (1A). The image bearing member satisfies mathematical formula (1B)

[00001]$\begin{array}{cc}R<13.771N^{0.4043}& \left(1.Math.A\right)\\ 0.60\frac{V}{\left(Q/S\right)\left(d/{\mathrm{.Math.}}_r.Math.{\mathrm{.Math.}}_0\right)}& \left(1.Math.B\right)\end{array}$

A method of producing an electrophotographic photoreceptor composed of a photosensitive layer provided on a conductive substrate, includes, in the formation of an outermost layer, controlling slope k of a straight line obtained by plotting the average film density of outermost layer and boiling point of solvent used for the formation of the outermost layer along the ordinate and the abscissa, respectively, to be 1.50E-4 (g/cm.sup.3.Math. C.) or greater, and adjusting the difference in film density of the outermost layer between the surface side and the side close to the conductive substrate to be 0.030 g/cm.sup.3 or less. The electrophotographic photoreceptor has reduced image defects even after long-term use and has excellent wear performance.

A bis-butadiene derivative is represented by general formula (1) shown below.

##STR00001##

In general formula (1), Ra, Rb, and Rc each represent, independently of one another, an alkyl group having a carbon number of at least 1 and no greater than 8 or an alkoxy group having a carbon number of at least 1 and no greater than 8. l and m each represent, independently of one another, an integer of at least 0 and no greater than 5. n represents an integer of at least 0 and no greater than 4. Chemical groups Ra may be the same as or different from each other. Chemical groups Rb may be the same as or different from each other. Chemical groups Rc may be the same as or different from each other.