Abstract: A semiconductor device includes a semiconductor laser chip having a first light-emitting surface which is formed on one end face of the semiconductor laser chip and which outputs a plurality of front beams, and a second light-emitting surface which is formed on an end face opposite to the first light-emitting surface and which outputs a plurality of back beams corresponding to the plurality of front beams. A photodetector is so formed on the semiconductor laser device as to face the second light-emitting surface of the semiconductor laser chip. The photodetector has a plurality of photodetecting portions for independently detecting the plurality of back beams output from the second light-emitting surface. The photodetector is in tight contact with the second light-emitting surface of the semiconductor laser chip.

Abstract: An image forming apparatus includes an image bearing member and a charge member for electrically charging the image bearing member while contacting the image bearing member. An oscillating voltage, including a component of AC voltage, is applied to the charge member. A first detector detects an average of the AC current applied to the charge member. A second detector detects a value of the AC current corresponding to a peak of the AC voltage. A controller effects control such that when a detected current value is smaller than a first predetermined value, the detected current value of the first detector is at the first predetermined value, and when the detected current value of the first detector is larger than the first predetermined value, a current value of the second detector is at a second predetermined value.

Abstract: An image forming apparatus includes an image bearing member and a charge member contacted to the image bearing member for electrically charging the image bearing member. An oscillating voltage including an AC voltage component is applied to the charge member. A first detector detects an AC current applied to the charge member and a second detector detects the AC current corresponding to a peak or a neighborhood of the peak of the AC voltage. A controller effects control such that current detected by the second detector is a predetermined level when the current detected by the first detector is within a predetermined range, and such that current detected by the first detector is a predetermined level when the current detected by the first detector is outside the predetermined range.

Abstract: A sheet attachment detecting apparatus includes a rotary member which is rotatable for conveying a sheet and whose surface is electrically conductive, an electrically conductive member which can be abutted on and separated from the surface of the rotary member, and an attachment detector which applies a power to the rotary member and the electrically conductive member for detecting the attachment of the sheet around the rotary member.

Abstract: An image forming apparatus is provided which is capable of positively preventing a recording sheet from being wound around a conveying means that conveys the recording sheet. A high voltage power supply section applies voltage to feeding brushes disposed in contact with the surface of a pressurizing roller having an electrically conductive surface. A winding sensor is disposed in contact with the surface of the pressurizing roller and is located in a sheet passing area of the pressurizing roller. A CPU sets a threshold voltage to a value corresponding to the temperature of the pressurizing roller detected by a temperature sensor, and detects whether the recording sheet is wound around the pressurizing roller, based upon the set threshold voltage and voltage of the pressurizing roller in the sheet passing area detected by the winding sensor.

Abstract: An image heating apparatus including a heater, a power supply for supplying electric power to the heater, and a time constant setting circuit for setting a time constant when the power supply starts the supply of electric power to the heater, the time constant setting means setting the time constant in conformity with the shut-off time of the supply of electric power to the heater.

Abstract: There is provided an image forming apparatus including an image forming unit for forming an image on either a free-size sheet of an arbitrary size other than a regular size or a regular-size sheet, a controlling unit for controlling, when the image forming unit forms the image on the regular-size sheet, a controlling target unit according to a size of the regular-size sheet, an inputting unit for inputting a size of the free-size sheet, and a converting unit for converting the size inputted by the inputting unit, to suit the converted size to the controlling performed by the controlling unit to the regular-size sheet, wherein the controlling unit performs the different controlling for each group of the sheet sizes, and the converting unit performs the converting to suit the size of the free-size sheet to the group.

Abstract: This specification discloses an image forming apparatus comprising a process cartridge detachably mountable with respect to the main body of the apparatus, the process cartridge being provided with an image bearing member and charging means for charging the image bearing member, a power supply for applying an alternating current voltage to the charging means, and control means for variably controlling an alternating current supplied from the power supply to the charging means in conformity with information about the use situation of the process cartridge. The specification also discloses a process cartridge detachably mountable with respect to the main body of the image forming apparatus.

Abstract: There is provided an image forming apparatus including an image forming unit for forming an image on either a free-size sheet of an arbitrary size other than a regular size or a regular-size sheet, a controlling unit for controlling, when the image forming unit forms the image on the regular-size sheet, a controlling target unit according to a size of the regular-size sheet, an inputting unit for inputting a size of the free-size sheet, and a converting unit for converting the size inputted by the inputting unit, to suit the converted size to the controlling performed by the controlling unit to the regular-size sheet, wherein the controlling unit performs the different controlling for each group of the sheet sizes, and the converting unit performs the converting to suit the size of the free-size sheet to the group.

Abstract: An image forming apparatus includes an image bearing member; a charge member for electrically charging the image bearing member while contacting to the image bearing member: voltage applying means for applying an oscillating voltage including a component of AC voltage to the charge member; first detecting means for detecting an average of the AC current applied to the charge member from the voltage applying means; second detecting means for detection a value of the AC current corresponding to a peak of the AC voltage; and control means for effecting control such that when a detected current value of the detecting means is smaller than a first predetermined value, the detected current value of the first detecting means is at the first predetermined value, and when the detected current value of the first detecting means is larger than the first predetermined value, a current value of the second detecting means is at a second predetermined value.

Abstract: An image forming apparatus including an image bearing member; a charge member contacted to the image bearing member to electrically charge the image bearing member; voltage applying means for applying to the charge member an oscillating voltage including an AC voltage component; first detecting means for detecting an AC current applied to the charge member from the voltage applying means; second detecting means for detecting the AC current corresponding to a peak or a neighborhood of the peak of the AC voltage; control means for effecting control such that current detected by the second detecting means is a predetermined level when the current detected by the first detecting means is within a predetermined range and such that current detected by the first detecting means is a predetermined level when the current detected by the first detecting means is outside the predetermined range.

Abstract: A sheet attachment detecting apparatus includes a rotary member which is rotatable for conveying a sheet and whose surface is electrically conductive, an electrically conductive member which can be abutted on and separated from the surface of the rotary member, and an attachment detector which applies a power to the rotary member and the electrically conductive member for detecting the attachment of the sheet around the rotary member.

Abstract: A semiconductor device includes a semiconductor laser chip having a first light-emitting surface which is formed on one end face of the semiconductor laser chip and which outputs a plurality of front beams, and a second light-emitting surface which is formed on an end face opposite to the first light-emitting surface and which outputs a plurality of back beams corresponding to the plurality of front beams. A photodetector is so formed on the semiconductor laser device as to face the second light-emitting surface of the semiconductor laser chip. The photodetector has a plurality of photodetecting portions for independently detecting the plurality of back beams output from the second light-emitting surface. The photodetector is in tight contact with the second light-emitting surface of the semiconductor laser chip.

Abstract: A laser light quantity control device includes a semiconductor laser element having a plurality of light emitting portions and a light quantity detector for detecting light quantities of the individual light emitting portions. Currents supplied to the individual light emitting portions are controlled by a light quantity adjusting section on the basis of outputs from the light quantity detector. The light quantity adjusting section performs light quantity adjustments of the individual light emitting portions at predetermined time interval.

Abstract: The present invention relates to an image forming apparatus which comprises an image bearing member for bearing a toner image, a transfer charger for transferring the toner image from the image bearing member to a transfer material, and an electricity removing member for removing electricity from the transfer material to separate the transfer material from the image bearing member, and wherein, when the electricity is removed from the transfer material by the electricity removing member, a potential level applied to the electricity removing member is selected so that the potential level at end portions of the transfer material becomes greater than the potential level at a central portion of the transfer material along a transfer material shifting direction, thereby improving separation of the transfer material from the image bearing member.

Abstract: A printer buffer unit is connectable to one or a plurality of host computers and one or a plurality of printers. The printer buffer unit has a unit for detecting a break of print job data sent from a host computer, and a unit for adding a job offset command at the time of the break in sending the print job data to a printer.

Abstract: A printer buffer unit is connectable to one or a plurality of host computers and one or a plurality of printers. The printer buffer unit has a unit for detecting a break of print job data sent from a host computer, and a unit for adding a job offset command at the time of the break in sending the print job data to a printer.

Abstract: An apparatus for generating a laser beam modulated on the basis of an information signal, which comprises a circuit for generating a first information signal, a circuit for generating a second information signal, independent of the first information signal, a circuit for driving a semiconductor laser on the basis of the first and the second information signals, wherein the driving circuit comprises first and second switching elements which operate supplementarily with each other, one of the first and second switching elements switches a drive current to the semiconductor laser, and wherein the first information signal is provided into a control terminal of the first switching element and the second information signal is provided into a control terminal of the second switching element.

Abstract: When a recording medium fed from a sheet feed drive mechanism is detected at a predetermined position, the counting of a loop feed time or the like variably set in accordance with a predetermined sheet feed condition such as the sheet type or particular supplying device is started, and the drive of the sheet feed drive mechanism is controlled by terminating the feeding operation in accordance with a count termination state. A count time of a timer for detecting a feed jam is variably set in accordance with a sheet feed condition such as material of sheet.

Abstract: An apparatus for generating a laser beam modulated on the basis of an information signal, which comprises a circuit for generating a first information signal, a circuit for generating a second information signal, independent of the first information signal, a circuit for driving a semiconductor laser on the basis of the first and the second information signals, wherein the driving circuit comprises first and second switching elements which operate supplementarily with each other, one of the first and second switching elements switches a drive current to the semiconductor laser, and wherein the first information signal is provided into a control terminal of the first switching element and the second information signal is provided into a control terminal of the second switching element.