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A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes a first frame; a second frame coupled with the first frame for rotation about a shaft relative to each other; a first electrical contact, provided in the first frame, for receiving

A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, includes a first frame; a second frame coupled with the first frame for rotation about a shaft relative to each other; a first electrical contact, provided in the first frame, for receiving, from the main assembly, a bias voltage to be supplied to the charging member; a second electrical contact, provided in the second frame, for receiving, from the main assembly, a bias voltage to be supplied to a developing member, a developer feeding member and a regulating member; and a third electrical contact, provided in the first frame coaxially with the drum, for electrically grounding the drum to the main assembly. The first and second contents are disposed at one end of the first frame and the second frame, respectively, and the third contact is disposed at the other end of the first frame, and wherein the contacts are disposed such that, the first contact takes a higher position than the second.

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What is claimed is: 1. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a first frame; a second frame, coupled with said first frame, wherein said first and second frames are configured and positioned to rotate about a shaft

What is claimed is: 1. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a first frame; a second frame, coupled with said first frame, wherein said first and second frames are configured and positioned to rotate about a shaft relative to each other, wherein said second frame comprises: a developer accommodating portion configured and positioned to accommodate a developer to be used for developing the electrostatic latent image, and said developer accommodating portion is provided with an upper transparent window and a lower transparent window at upper and lower positions, respectively, when said process cartridge is mounted to the main assembly of the image forming apparatus; a lower light guide portion configured and positioned to guide, to said lower transparent window, light emitted by a light emission member provided in the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, said lower light guide portion extending from said lower transparent window toward said one longitudinal end of said second frame; and an upper light guide portion configured and positioned to guide, to a light receiving element provided in the main assembly of the image forming apparatus, the light having passed through the inside of said developer accommodating portion and through said upper transparent window when said process cartridge is mounted to the main assembly of the image forming apparatus, said upper light guide portion extending from said upper transparent window toward said one end of said second frame, thus permitting the main assembly of the apparatus to detect a reduction of the amount of the developer accommodated in said developer accommodating portion beyond a predetermined amount by reception of a predetermined light quantity by the light receiving element; an electrophotographic photosensitive drum provided in said first frame; a photosensitive drum charging member, provided in said first frame, configured and positioned to electrically charge said electrophotographic photosensitive drum; a developing member, provided in said second frame, configured and positioned to develop an electrostatic latent image formed on said photosensitive drum with a developer; a developer feeding member, provided in said second frame, configured and positioned to supply a developer onto a peripheral surface of said developing member; a regulating member, provided in said second frame, configured and positioned to regulate an amount of the developer deposited on the peripheral surface of said developing member; an electrical contact, provided in said first frame, configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member when said process cartridge is mounted to the main assembly of the image forming apparatus; an electrical contact, provided in said second frame, configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member when said process cartridge is mounted to the main assembly of the image forming apparatus; and a ground electrical contact, provided in said first frame coaxially with said photosensitive drum, configured and positioned to electrically ground said photosensitive drum to the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said first frame has one and the other longitudinal ends, and said second frame has one and the other longitudinal ends adjacent said one and the other longitudinal ends of said first frame, respectively, and wherein said electrical contact configured and positioned to receive a bias voltage to be supplied to said photosensitive drum charging member and said electrical contact configured and positioned to receive a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member are disposed adjacent to said one longitudinal ends of said first frame and said second frame, respectively, and said ground electrical contact is disposed adjacent to the other longitudinal end of said first frame, and wherein said electrical contacts are disposed such that when said process cartridge is mounted to the main assembly of said image forming apparatus, said electrical contact configured and positioned to receive a bias voltage to be supplied to said photosensitive drum charging member takes a higher position than said electrical contact configured and positioned to receive a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member. 2. A process cartridge according to claim 1, wherein said second frame is provided with a developer charging member configured and positioned to electrically charge the developer deposited on the peripheral surface of said developing member and an electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developer charging member when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said electrical contact configured and positioned to receive a bias voltage to be supplied to said developer charging member is disposed adjacent to said one longitudinal end of said second frame at a position between said electrical contact configured and positioned to receive a bias voltage to be supplied to said photosensitive drum charging member and said electrical contact configured and positioned to receive a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member. 3. A process cartridge according to claim 1 or 2, further comprising a coupling member configured and positioned to receive, from the main assembly of the image forming apparatus, a driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said ground electrical contact projects from an end surface of said coupling member. 4. A process cartridge according to claim 2, wherein said electrical contact configured and positioned to receive a bias voltage to be supplied to said photosensitive drum charging member, said electrical contact configured and positioned to receive a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member, and said electrical contact configured and positioned to receive a bias voltage to be supplied to said developer charging member are disposed downstream of a center of relative rotation between said first frame and said second frame with respect to a direction in which said process cartridge is mounted to the main assembly. 5. A process cartridge according to claim 1, wherein an end surface at one longitudinal end of the lower light guide portion is disposed inside said one longitudinal end of said second frame. 6. An electrophotographic image forming apparatus for forming an image on a recording material to which a process cartridge is detachably mountable, said apparatus comprising: (a) an electrical contact positioned in a main assembly of said apparatus and configured and positioned to supply a bias voltage to a photosensitive drum charging member; (b) an electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to a developing member, a developer feeding member, and a regulating member; (c) a ground electrical contact positioned in the main assembly of said apparatus; and (d) a cartridge mounting portion configured and positioned to detachably mount the process cartridge, the process cartridge including: a first frame; a second frame coupled with the first frame, wherein the first and second frames are configured and positioned to rotate about a shaft relative to each other, wherein the second frame comprises: a developer accommodating portion configured and positioned to accommodate a developer to be used for developing the electrostatic latent image, and the developer accommodating portion is provided with an upper transparent window and a lower transparent window at upper and lower positions, respectively, when the process cartridge is mounted to a main assembly of said image forming apparatus; a lower light guide portion configured and positioned to guide, to the lower transparent window, light emitted by a light emission member provided in the main assembly of said image forming apparatus when the process cartridge is mounted to the main assembly of said image forming apparatus, the lower light guide portion extending from the lower transparent window toward the one longitudinal end of the second frame; and an upper light guide portion configured and positioned to guide, to a light receiving element provided in the main assembly of said image forming apparatus, the light having passed through the inside of the developer accommodating portion and through the upper transparent window when the process cartridge is mounted to the main assembly of said image forming apparatus, the upper light guide portion extending from the upper transparent window toward the one end of the second frame, thus permitting the main assembly of said apparatus to detect a reduction of the amount of the developer accommodated in the developer accommodating portion beyond a predetermined amount by reception of a predetermined light quantity by the light receiving element; an electrophotographic photosensitive drum provided in the first frame; the photosensitive drum charging member, provided in the first frame, configured and positioned to electrically charge the electrophotographic photosensitive drum; the developing member, provided in the second frame, configured and positioned to develop an electrostatic latent image formed on the photosensitive drum with a developer; the developer feeding member, provided in the second frame, configured and positioned to supply a developer onto a peripheral surface of the developing member; the regulating member, provided in the second frame, configured and positioned to regulate an amount of the developer deposited on the peripheral surface of the developing member; an electrical contact, provided in the first frame, configured and positioned to contact said electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to the photosensitive drum charging member and to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member when the process cartridge is mounted to the main assembly of said image forming apparatus; an electrical contact, provided in the second frame, configured and positioned to contact said electrical contact configured and positioned to supply a bias voltage to the developing member, the developer feeding member, and the regulating member and to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member and the regulating member when the process cartridge is mounted to the main assembly of said image forming apparatus; and a ground electrical contact, provided in the first frame coaxially with the photosensitive drum, configured and positioned to contact said ground electrical contact positioned in the main assembly of said apparatus to electrically ground the photosensitive drum to the main assembly of said image forming apparatus when the process cartridge is mounted to the main assembly of said image forming apparatus, wherein the first frame has one and the other longitudinal ends, and the second frame has one and the other longitudinal ends adjacent the one and the other longitudinal ends of the first frame, respectively, and wherein the electrical contact configured and positioned to receive a bias voltage to be supplied to the photosensitive drum charging member and the electrical contact configured and positioned to receive a bias voltage to be supplied to the developing member, the developer feeding member and the regulating member are disposed adjacent to the one longitudinal ends of the first frame and the second frame, respectively, and the ground electrical contact positioned in the first frame is disposed adjacent to the other longitudinal end of the first frame, and wherein the electrical contacts are disposed such that when the process cartridge is mounted to the main assembly of said image forming apparatus, the electrical contact configured and positioned to receive a bias voltage to be supplied to the photosensitive drum charging member takes a higher position than the electrical contact configured and positioned to receive a bias voltage to be supplied to the developing member, the developer feeding member and the regulating member. 7. An apparatus according to claim 6, further comprising: an electrical contact positioned in a main assembly of said apparatus and configured and positioned to supply a bias voltage to a developer charging member, wherein the second frame is provided with the developer charging member, which is configured and positioned to electrically charge the developer deposited on the peripheral surface of the developing member, and an electrical contact configured and positioned to contact said electrical contact positioned in a main assembly of said apparatus and configured and positioned to supply a bias voltage to the developer charging member, to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developer charging member when the process cartridge is mounted to the main assembly of said image forming apparatus, wherein the electrical contact positioned and configured to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developer charging member is disposed adjacent to the one longitudinal end of the second frame at a position between the electrical contact configured and positioned to receive a bias voltage to be supplied to the photosensitive drum charging member and the electrical contact configured and positioned to receive a bias voltage to be supplied to the developing member, the developer feeding member and the regulating member. 8. An apparatus according to claim 6 or 7, further comprising the light emission member and the light receiving element disposed adjacent the one longitudinal ends of the first frame and the second frame of the process cartridge when the process cartridge is mounted to the main assembly of said apparatus, wherein said light receiving element is disposed above said light emission. 9. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a first frame; a second frame coupled with said first frame, wherein said first and second frames are configured and positioned to rotate about a shaft relative to each other; an electrophotographic photosensitive drum provided in said first frame; a photosensitive drum charging member, provided in said first frame, configured and positioned to electrically charge said electrophotographic photosensitive drum; a developing member, provided in said second frame, configured and positioned to develop an electrostatic latent image formed on said photosensitive drum with a developer; a developer feeding member, provided in said second frame, configured and positioned to supply a developer onto a peripheral surface of said developing member; a regulating member, provided in said second frame, configured and positioned to regulate an amount of the developer deposited on the peripheral surface of said developing member; an electrical contact, provided in said first frame, configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member when said process cartridge is mounted to the main assembly of the image forming apparatus; an electrical contact, provided in said second frame, configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member when said process cartridge is mounted to the main assembly of the image forming apparatus; and a ground electrical contact, provided in said first frame coaxially with said photosensitive drum, configured and positioned to electrically ground the photosensitive drum to the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said first frame has one and the other longitudinal ends, and said second frame has one and the other longitudinal ends adjacent said one and the other longitudinal ends of said first frame, respectively, and wherein said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member and said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member are disposed adjacent to said one longitudinal ends of said first frame and said second frame, respectively, and said ground electrical contact is disposed adjacent to the other longitudinal end of said first frame, and wherein said electrical contacts are disposed such that when said process cartridge is mounted to the main assembly of the image forming apparatus, said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member takes a higher position than said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member, wherein said second frame is provided with a developer charging member configured and positioned to electrically charge the developer deposited on the peripheral surface of said developing member and an electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developer charging member when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developer charging member is disposed adjacent to said one longitudinal end of said second frame at a position between said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member and said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member, wherein said second frame has a developer accommodating portion configured and positioned to accommodate a developer to be used for developing the electrostatic latent image, and said developer accommodating portion is provided with an upper transparent window and a lower transparent window at upper and lower positions, respectively, when said process cartridge is mounted to the main assembly of said image forming apparatus, said second frame further comprising a lower light guide portion configured and positioned to guide, to said lower transparent window, light emitted by a light emission member provided in the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, said lower light guide portion extending from said lower transparent window toward said one longitudinal end of said second frame, said second frame further comprising an upper light guide portion configured and positioned to guide, to a light receiving element provided in the main assembly of the image forming apparatus, the light having passed through the inside of said developer accommodating portion and through said upper transparent window when said process cartridge is mounted to the main assembly of the image forming apparatus, said upper light guide portion extending from said upper transparent window toward said one end of said second frame, thus permitting the main assembly of the apparatus to detect a reduction of an amount of the developer accommodated in said developer accommodating portion beyond a predetermined amount by reception of a predetermined light quantity by the light receiving element. 10. A process cartridge according to claim 9, further comprising a coupling member configured and positioned to receive, from the main assembly of the image forming apparatus, a driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said ground electrical contact projects from an end surface of said coupling member. 11. A process cartridge according to claim 9, wherein an end surface at one longitudinal end of the lower light guide portion is disposed inside said one longitudinal end of said second frame. 12. A process cartridge according to claim 9 or 11, wherein said upper light guide portion is disposed between said first frame and said second frame at one longitudinal end of an optical path through which a laser beam to be directed to said photosensitive drum from the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, is passed. 13. A process cartridge according to claim 9, 10 or 11, wherein said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member, said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member, and said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developer charging member are disposed downstream of a center of relative rotation between said first frame and said second frame with respect to a direction in which said process cartridge is mounted to the main assembly. 14. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: a first frame; a second frame coupled with said first frame, wherein said first and second frames are configured and positioned to rotate about a shaft relative to each other; an electrophotographic photosensitive drum provided in said first frame; a photosensitive drum charging member, provided in said first frame, configured and positioned to electrically charge said electrophotographic photosensitive drum; a developing member, provided in said second frame, configured and positioned to develop an electrostatic latent image formed on said photosensitive drum with a developer; a developer feeding member, provided in said second frame, configured and positioned to supply a developer onto a peripheral surface of said developing member; a regulating member, provided in said second frame, configured and positioned to regulate an amount of the developer deposited on the peripheral surface of said developing member; an electrical contact, provided in said first frame, configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member when said process cartridge is mounted to the main assembly of the image forming apparatus; an electrical contact, provided in said second frame, configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member when said process cartridge is mounted to the main assembly of the image forming apparatus; and a ground electrical contact provided in said first frame coaxially with said photosensitive drum configured and positioned to electrically ground said photosensitive drum to the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said first frame has one and the other longitudinal ends, and said second frame has one and the other longitudinal ends adjacent said one and the other longitudinal ends of said first frame, respectively, and wherein said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member and said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member are disposed adjacent to said one longitudinal ends of said first frame and said second frame, respectively, and said ground electrical contact is disposed adjacent to the other longitudinal end of said first frame, and wherein said electrical contacts are disposed such that when said process cartridge is mounted to the main assembly of the image forming apparatus, said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member takes a higher position than said electrical contact configured and positioned to receiver, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member, wherein said second frame is provided with a developer charging member configured and positioned to electrically charge the developer deposited on the peripheral surface of said developing member and an electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developer charging member when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developer charging member is disposed adjacent to said one longitudinal end of said second frame at a position between said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member and said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member, wherein said second frame has a developer accommodating portion configured and positioned to accommodate a developer to be used for developing the electrostatic latent image, and said developer accommodating portion is provided with an upper transparent window and a lower transparent window at upper and lower positions, respectively, when said process cartridge is mounted to the main assembly of said image forming apparatus, said second frame further comprising a lower light guide portion configured and positioned to guide, to said lower transparent window, light emitted by a light emission member provided in the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, said lower light guide portion extending from said lower transparent window toward said one longitudinal end of said second frame, said second frame further comprising an upper light guide portion configured and positioned to guide, to a light receiving element provided in the main assembly of the image forming apparatus, the light having passed through the inside of said developer accommodating portion and through said upper transparent window when said process cartridge is mounted to the main assembly of the image forming apparatus, said upper light guide portion extending from said upper transparent window toward said one end of said second frame, thus permitting the main assembly of the apparatus to detect a reduction of an amount of the developer accommodated in said developer accommodating portion beyond a predetermined amount by reception of a predetermined light quantity by the light receiving element, said process cartridge further comprising a coupling member configured and positioned to receive, from the main assembly of the image forming apparatus, a driving force for rotating said photosensitive drum when said process cartridge is mounted to the main assembly of the image forming apparatus, wherein said ground electrical contact projects from an end surface of said coupling member, wherein an end surface at one longitudinal end of said lower light guide portion is disposed inside said one longitudinal end of said second frame. 15. A process cartridge according to claim 14, wherein said upper light guide portion is disposed between said first frame and said second frame at one longitudinal end of an optical path through which a laser beam to be directed to said photosensitive drum from the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, is passed. 16. A process cartridge according to claim 14 or 15, wherein said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said photosensitive drum charging member, said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developing member, said developer feeding member, and said regulating member and said electrical contact configured and positioned to receive, from the main assembly of the image forming apparatus, a bias voltage to be supplied to said developer charging member are disposed downstream of a center of relative rotation between said first frame and said second frame with respect to a direction in which said process cartridge is mounted to the main assembly. 17. A process cartridge according to claim 1, 5, 9, or 14, wherein said upper light guide portion is disposed between said first frame and said second frame at one longitudinal end of an optical path through which a laser beam to be directed to said photosensitive drum from the main assembly of the image forming apparatus when said process cartridge is mounted to the main assembly of the image forming apparatus, is passed. 18. An electrophotographic image forming apparatus for forming an image on a recording material to which a process cartridge is detachably mountable, said apparatus comprising: (a) an electrical contact positioned in a main assembly of said apparatus and configured and positioned to supply a bias voltage to a photosensitive drum charging member; (b) an electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to a developing member, a developer feeding member, and a regulating member; (c) a ground electrical contact positioned in the main assembly of said apparatus; (d) a cartridge mounting portion configured and positioned to detachably mount the process cartridge, the process including: a first frame; a second frame coupled with the first frame, wherein the first and second frames are positioned and configured to rotate about a shaft relative to each other; an electrophotographic photosensitive drum provided in the first frame; the photosensitive drum charging member, provided in the first frame, configured and positioned to electrically charge the electrophotographic photosensitive drum; the developing member, provided in the second frame, configured and positioned to develop an electrostatic latent image formed on the photosensitive drum with a developer; the developer feeding member, provided in the second frame, configured and positioned to supply a developer onto a peripheral surface of the developing member; the regulating member, provided in the second frame, configured and positioned to regulate an amount of the developer deposited on the peripheral surface of the developing member; an electrical contact, provided in the first frame, configured and positioned to contact said electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to the photosensitive drum charging member and to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member when the process cartridge is mounted to the main assembly of said image forming apparatus; an electrical contact provided in the second frame, configured and positioned to contact said electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to the developing member, the developer feeding member, and the regulating member and to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member, and the regulating member when the process cartridge is mounted to the main assembly of said image forming apparatus; a ground electrical contact, provided in the first frame coaxially with the photosensitive drum, configured and positioned to contact said ground electrical contact positioned in the main assembly of said apparatus to electrically ground the photosensitive drum to the main assembly of said image forming apparatus when the process cartridge is mounted to the main assembly of said image forming apparatus, wherein the first frame has one and the other longitudinal ends, and the second frame has one and the other longitudinal ends adjacent said one and the other longitudinal ends of the first frame, respectively, and wherein the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member and the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member, and the regulating member are disposed adjacent to said one longitudinal ends of the first frame and the second frame, respectively, and the ground electrical contact provided in the first frame is disposed adjacent to the other longitudinal end of the first frame, and wherein the electrical contacts are disposed such that when the process cartridge is mounted to the main assembly of said image forming apparatus, the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member takes a higher position than the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member, and the regulating member; and (e) an electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to a developer charging member, wherein the second frame is provided with the developer charging member configured and positioned to electrically charge the developer deposited on the peripheral surface of the developing member and an electrical contact configured and positioned to contact said electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to a developer charging member and to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developer charging member when the process cartridge is mounted to the main assembly of said image forming apparatus, wherein the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developer charging member is disposed adjacent to said one longitudinal end of the second frame at a position between the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member and the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member, and the regulating member, wherein the second frame has a developer accommodating portion configured and positioned to accommodate a developer to be used for developing the electrostatic latent image, and the developer accommodating portion is provided with an upper transparent window and a lower transparent window at upper and lower positions, respectively, when the process cartridge is mounted to the main assembly of said image forming apparatus, the second frame further comprising a lower light guide portion configured and positioned to guide, to the lower transparent window, light emitted by a light emission member provided in the main assembly of said image forming apparatus when the process cartridge is mounted to the main assembly of said image forming apparatus, the lower light guide portion extending from the lower transparent window toward said one longitudinal end of the second frame, the second frame further comprising an upper light guide portion configured and positioned to guide, to a light receiving element provided in the main assembly of said image forming apparatus, the light having passed through the inside of the developer accommodating portion and through the upper transparent window when the process cartridge is mounted to the main assembly of said image forming apparatus, the upper light guide portion extending from the upper transparent window toward said one end of the second frame, thus permitting the main assembly of said apparatus to detect a reduction of an amount of the developer accommodated in the developer accommodating portion beyond a predetermined amount by reception of a predetermined light quantity by said light receiving element. 19. An electrophotographic image forming apparatus for forming an image on a recording material to which a process cartridge is detachably mountable, said apparatus comprising: (a) an electrical contact positioned in a main assembly of said apparatus and configured and positioned to supply a bias voltage to a photosensitive drum charging member; (b) an electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to a developing member, a developer feeding member, and a regulating member; (c) a ground electrical contact positioned in the main assembly of said apparatus; (d) a cartridge mounting portion configured and positioned to detachably mount the process cartridge, the process cartridge including: a first frame; a second frame coupled with the first frame, wherein the first and second frames are configured and positioned to rotate about a shaft relative to each other; an electrophotographic photosensitive drum provided in the first frame; the photosensitive drum charging member, provided in the first frame, configured and positioned to electrically charge the electrophotographic photosensitive drum; the developing member, provided in the second frame, configured and positioned to develop an electrostatic latent image formed on the photosensitive drum with a developer; the developer feeding member, provided in the second frame, configured and positioned to supply a developer onto a peripheral surface of said developing member; the regulating member, provided in the second frame, configured and positioned to regulate an amount of the developer deposited on the peripheral surface of the developing member; an electrical contact, provided in the first frame, configured and positioned to contact said electrical contact positioned in a main assembly of said apparatus and configured and positioned to supply a bias voltage to the photosensitive drum charging member and to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member when the process cartridge is mounted to the main assembly of said image forming apparatus; an electrical contact, provided in the second frame, configured and positioned to contact said electrical contact positioned in the main assembly of said apparatus and configured and positioned to supply a bias voltage to the developing member, the developer feeding member, and the regulating member and to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member and the regulating member when the process cartridge is mounted to the main assembly of said image forming apparatus; a ground electrical contact, provided in the first frame coaxially with the photosensitive drum, configured and positioned to contact said ground electrical contact positioned in said main assembly of said apparatus to electrically ground the photosensitive drum to the main assembly of said image forming apparatus when the process cartridge is mounted to the main assembly of said image forming apparatus, wherein the first frame has one and the other longitudinal ends, and the second frame has one and the other longitudinal ends adjacent the one and the other longitudinal ends of the first frame, respectively, and wherein the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member and the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member and the regulating member are disposed adjacent to the one longitudinal ends of the first frame and the second frame, respectively, and the ground electrical contact provided in the first frame is disposed adjacent to the other longitudinal end of the first frame, and wherein the electrical contacts are disposed such that when the process cartridge is mounted to the main assembly of said image forming apparatus, the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member takes a higher position than the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member and the regulating member, and (e) an electrical contact positioned in the main assembly of said apparatus and positioned and configured to supply a bias voltage to a developer charging member, wherein the second frame is provided with the developer charging member configured and positioned to electrically charge the developer deposited on the peripheral surface of the developing member, and an electrical contact configured and positioned to contact said electrical contact positioned in the main assembly of said apparatus and positioned and configured to supply a bias voltage to a developer charging member and to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developer charging member when the process cartridge is mounted to the main assembly of said image forming apparatus, wherein the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developer charging member is disposed adjacent to said one longitudinal end of the second frame at a position between the electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the photosensitive drum charging member and said electrical contact configured and positioned to receive, from the main assembly of said image forming apparatus, a bias voltage to be supplied to the developing member, the developer feeding member and the regulating member, said process cartridge further including a coupling member configured and positioned to receive, from the main assembly of said image forming apparatus, a driving force for rotating the photosensitive drum when the process cartridge is mounted to the main assembly of said image forming apparatus, wherein the ground electrical contact provided in said first frame projects from an end surface of the coupling member, wherein the second frame has a developer accommodating portion configured and positioned to accommodate a developer to be used for developing the electrostatic latent image, and the developer accommodating portion is provided with an upper transparent window and a lower transparent window at upper and lower positions, respectively, when the process cartridge is mounted to the main assembly of said image forming apparatus, the second frame further comprising a lower light guide portion configured and positioned to guide, to the lower transparent window, light emitted by a light emission member provided in the main assembly of said image forming apparatus when the process cartridge is mounted to the main assembly of said image forming apparatus, said lower light guide portion extending from the lower transparent window toward said one longitudinal end of the second frame, the second frame further comprising an upper light guide portion configured and positioned to guide, to a light receiving element provided in the main assembly of said image forming apparatus, the light having passed through the inside of the developer accommodating portion and through the upper transparent window when the process cartridge is mounted to the main assembly of said image forming apparatus, the upper light guide portion extending from the upper transparent window toward said one end of the second frame, thus permitting the main assembly of said apparatus to detect a reduction of an amount of the developer accommodated in the developer accommodating portion beyond a predetermined amount by reception of a predetermined light quantity by said light receiving element, wherein an end surface at one longitudinal end of the lower light guide portion is disposed inside said one longitudinal end of the second frame. 20. An electrophotographic image forming apparatus according to claim 6, 17, or 18, wherein the upper light guide portion is disposed between the first frame and the second frame at one longitudinal end of an optical path through which a laser beam to be directed to the photosensitive drum from the main assembly of said image forming apparatus when the process cartridge is mounted to the main assembly of said image forming apparatus, is passed.