Abstract: An image forming apparatus includes a rotatable image bearing member on which an electrostatic latent image is formed; a charging member for being supplied with a charging voltage which is a DC voltage not having an AC voltage component and for contacting the bearing member to electrically charge a surface of the bearing member using an electric discharge; a transfer member for transferring onto a transfer material a toner image formed on the surface of the bearing member by developing the electrostatic latent image, at a transfer position; wherein the charging potential of the charging member is different between when the charging member provides a first region with a potential and when the charging member provides a second region with a potential, thus providing a predetermined potential difference between the first region and the second region, and wherein the transfer member is not supplied with a voltage when the second region is at the transfer position, where the first region is a region on the image b

Abstract: An electrophotographic image forming apparatus forming an image on a recording medium, includes: an electrophotographic photosensitive member having a photoconductive layer on a rigid base; an exposure device forming a latent image on the electrophotographic photosensitive member; a developer carrying member that carries a developer to develop the latent image using the developer in contact with the electrophotographic photosensitive member; and a cleaning blade that cleans the electrophotographic photosensitive member in contact with the electrophotographic photosensitive member, wherein the following expression is satisfied: Le?Ldr>Lcl, where Le: a longitudinal length of the photoconductive layer Le, Ldr: a longitudinal length of the developer carrying member to be contacted with the electrophotographic photosensitive member, and Lcl: a longitudinal length of the cleaning blade to be contacted with the electrophotographic photosensitive member.

Abstract: An electrophotographic image forming apparatus for forming an image on a recording material, to which a cartridge is detachably mountable. The cartridge includes portion for accommodating a developer for developing an electrostatic latent image formed on an electrophotographic photosensitive member, a roller for developing the electrostatic latent image with the developer, an opening for supplying the developer to the developing roller from the developer accommodating portion, and a sealing member for unsealably sealing the developer supply opening. The apparatus includes a detector for detecting that amount of the developer deposited on a member to be detected is less than a predetermined level, a retractor for producing an electric signal for retracting the sealing member from a sealing position where the sealing member seals the developer supply opening, when the detector detects that amount of the developer deposited on the member to be detected is less than the predetermined level.

Abstract: A developing apparatus including: a developer carrying member for carrying a developer, the developer carrying member being provided with an elastic layer and adapted to develop, with a developer, an electrostatic image formed on an image bearing member; wherein the developer includes a toner, the toner has a shape factor SF-1 of 100 or more but less than 130, the toner has a storage modulus G? (140° C.) at 140° C. of 2.0×103 dN/m2 or more but less than 2.0×104 dN/m2, the toner has a temperature, when the toner has a viscosity of 1.0×103 Pa·s in a flow tester temperature elevation method, of 115° C. or more but less than 130° C., and, in a surface roughness of the developer carrying member, a center-line mean roughness Ra, a ten-point mean roughness Rz and a mean spacing Sm of irregularities satisfy following relationships (1): 0.06 ? Rz / Sm ? 0.4 0.8 ? Ra ? 2.0 ? ? ( ? ? ? m ) } .

Abstract: A color electrophotographic image forming apparatus for forming an image on a recording material, includes (i) a mounting portion for detachably mounting process cartridges developing images with different colors and each including an electrophotographic photosensitive drum and a developing roller for developing an latent image formed on the drum, wherein roller is movable between a contact state contacting the drum and a spaced state spaced from the drum; (ii) a switching device switching the rollers between the contact and spacing states; (iii) a feeding belt for feeding the recording material along all of the drums; (iv) a controller for switching between a first monochrome mode in which the belt contacts all of the drums and a second monochrome mode in which the belt contacts only the drum of the cartridge which develops the latent image for image formation.

Abstract: A charging device for electrically charging an image bearing member, includes a contact charging member contactable to the image bearing member to charge the image bearing member, the contact charging member being supplied only with a DC voltage; and a contact member contacted to the charging member, wherein the image bearing member is adapted to carry a toner image of toner which contains an externally added material comprising silica, wherein work functions of the charging member, the contact member and the silica satisfy, (the work function of the contact member)>(the work function of the silica)>(the work function of the charging member).

Abstract: An image forming apparatus includes a rotatable image bearing member on which an electrostatic latent image is formed; a charging member for being supplied with a charging voltage which is a DC voltage not having an AC voltage component and for contacting the bearing member to electrically charge a surface of the bearing member using an electric discharge; a transfer member for transferring onto a transfer material a toner image formed on the surface of the bearing member by developing the electrostatic latent image, at a transfer position; wherein the charging potential of the charging member is different between when the charging member provides a first region with a potential and when the charging member provides a second region with a potential, thus providing a predetermined potential difference between the first region and the second region, and wherein the transfer member is not supplied with a voltage when the second region is at the transfer position, where the first region is a region on the image b

Abstract: An electrophotographic image forming apparatus for forming an image on a recording material, to which a cartridge is detachably mountable, includes a) a cartridge including, a developer accommodating portion for accommodating a developer for developing an electrostatic latent image formed on an electrophotographic photosensitive member, a developing roller for developing an electrostatic latent image with a developer, a developer supply opening for supplying the developer to the developing roller form the developer accommodating portion, and a sealing member for unsealably sealing the developer supply opening; b) developer detecting means for detecting that amount of the developer deposited on a member to be detected is less than a predetermined level; c) sealing member retracting means for producing an electric signal for retracting the sealing member sealing the developer supply opening from a sealing position where the sealing member seals the developer supply opening, when the detecting means detects that

Abstract: A developing apparatus including: a developer carrying member for carrying a developer, the developer carrying member being provided with an elastic layer and adapted to develop, with a developer, an electrostatic image formed on an image bearing member; wherein the developer includes a toner, the toner has a shape factor SF-1 of 100 or more but less than 130, the toner has a storage modulus G? (140° C.) at 140° C. of 2.0×103 dN/m2 or more but less than 2.0×104 dN/m2, the toner has a temperature, when the toner has a viscosity of 1.0×103 Pa·s in a flow tester temperature elevation method, of 115° C. or more but less than 130° C., and, in a surface roughness of the developer carrying member, a center-line mean roughness Ra, a ten-point mean roughness Rz and a mean spacing Sm of irregularities satisfy following relationships (1): 0.06 ? Rz / Sm ? 0.4 0.8 ? Ra ? 2.

Abstract: A color electrophotographic image forming apparatus for forming an image on a recording material, includes (i) a mounting portion for detachably mounting a plurality of process cartridges each including an electrophotographic photosensitive drum and a developing roller for developing an latent image formed on the drum, wherein developing roller is movable between a contact state where the developing roller is contacted to the drum and a spaced state where the developing roller is spaced from the drum, wherein the cartridges develop the latent images with colors different from each other; (ii) switching means for switching the developing rollers between the contact state and the spacing state when the cartridges are set in the mounting portions; (iii) a feeding belt for feeding the recording material along all of the drums of the cartridges set in the mounting portion; (iv) control means for switching, in accordance with a kind of the recording material in a monochromatic mode operation, between a first mode i

Abstract: A driving device is for driving a liquid crystal display in accordance with a display data signal. A shift register circuit produces first through N-th control signals from first through N-th shift output terminals, respectively, in synchronism with the clock signal, where N represents a positive integer greater than one. First through N-th output circuit produces first through N-th gradation voltages in correspondence with the display data signal in synchronism with the first through the N-th control signals, respectively. An additional output circuit produces an additional gradation voltage in correspondence with the display data signal in synchronism with an additional control signal. A connecting circuit connects the additional output circuit to an n-th shift output terminal instead of an n-th output circuit when the n-th output circuit becomes faulty, where n is a variable between one and N, both of inclusive.

Abstract: A driver circuit to drive a display by inverting the voltage polarity operates with a reduced power consumption. The driver circuit includes a driving voltage selector circuit including positive and negative driving voltage selector circuits alternately arranged therein and a circuit which conducts a change-over operation between a state in which signals respectively from the positive and negative driving voltage selector circuits are respectively outputted to first and second terminals in a first horizontal period and a state in which signals respectively from the positive and negative driving voltage selector circuits are respectively sent to second and first terminals in a second horizontal period.

Abstract: A complementary type MOS field effect transistor circuit includes an input terminal, a P-MOS FET, an N-MOS FET connected in series with the P-MOS FET, a first resistor connected between the input terminal and the gate of the P-MOS FET, a second resistor connected between the input terminal and the gate of the N-MOS FET, a first diode connected between the gate of the P-MOS FET and a high voltage power supply terminal and a second diode connected between the gate of the N-MOS FET and a low voltage power supply terminal. The gate protection circuit of the circuit has a first part of the first resistor and the second diode and a second part of the second resistor and the second diode.