摘要:
In one embodiment, a predetermined period different from a fixing process period in which fixing of toner to recording paper is carried out is set as a toner removal period, and during the toner removal period a hot roller and a pressure roller are intermittently rotated, and separation claws in contact with the rollers are caused to vibrate by the intermittent rotation of the rollers such that toner adhered to the separation claws is caused to drop due to this and is removed. Also, faces of the separation claws that oppose the surfaces of the hot roller and the pressure roller are set in a convex shape.
摘要:
In one embodiment, a predetermined period different from a fixing process period in which fixing of toner to recording paper is carried out is set as a toner removal period, and during the toner removal period a hot roller and a pressure roller are intermittently rotated, and separation claws in contact with the rollers are caused to vibrate by the intermittent rotation of the rollers such that toner adhered to the separation claws is caused to drop due to this and is removed. Also, faces of the separation claws that oppose the surfaces of the hot roller and the pressure roller are set in a convex shape.
摘要:
The fixing device includes a pair of rotating bodies which conveys a recording medium between a nip; a heating unit which heats at least one of the rotating bodies; and a temperature detection unit which detects a temperature of at least one of the rotating bodies. The temperature detection unit detects a temperature change until an image forming apparatus is normally operated since the heating unit starts the heating, and the temperature change is stored. It is judged that the image forming apparatus is in an abnormal state when the temperature detection unit detects a temperature change different from the temperature change in the normal operation. A temperature control unit stops passage of current through the heating unit when it is judged that the image forming apparatus is in the abnormal state.
摘要:
A duty correction circuit is formed using at least one delay circuit, which is constituted of a first inverter including three transistors of different conduction types and a second inverter including three other transistors of different conduction types and which delays and adjusts an input clock signal at the leading-edge/trailing-edge timing so as to convert it into an output clock signal based on a first or second bias voltage produced by a bias circuit detecting the duty ratio of the output clock signal. The duty correction circuit decreases the high-level period of the output clock signal having a high duty ratio based on the first bias voltage. Alternatively, the duty correction circuit increases the high-level period of the output clock signal having a low duty ratio based on the second bias voltage.
摘要:
Disclosed is a timing control circuit that receives a first clock having a period T1, a group of second clocks of L different phases spaced apart from each other at substantially equal intervals and selection signals m, n supplied thereto and generates a fine timing signal delayed from the rising edge of the first clock signal by a delay td of approximately td=m·T1+n·(T2/L). The timing control circuit includes a coarse delay circuit and a fine delay circuit. The coarse delay circuit includes a counter for counting a rising edge of the first clock signal after an activate signal is activated and generates a coarse timing signal whose amount of delay from the first clock signal is approximately m·T1. The fine delay circuit comprises L-number of multiphase clock control delay circuits disposed in parallel, delays by n·T2/L the timing of sampling of the coarse timing signal by respective clocks of the group of L-phase second clocks, and takes the OR among the resulting delayed pulses to thereby produce the fine timing signal.
摘要:
In an image forming apparatus of the present invention, an idle roller once stops rotating when a front edge of a sheet conveyed reaches the idle roller. The idle roller restarts rotating at such a timing that a front edge of a toner image on a photoreceptor and a front edge of an image writing position on the sheet are aligned with each other. Then, even if a rear edge of the sheet is still in the idle roller, the idle roller stops rotating when the front edge of the sheet is sandwiched between a transfer roller and the photoreceptor. By carrying out such operations, it is possible to avoid by a very simple way an occurrence of a slip phenomenon that is a phenomenon of slipping of the sheet with respect to the photoreceptor while suppressing a reduction in image quality as much as possible. In addition, it is also possible to surely secure a blank space formed at a rear edge portion of the sheet.
摘要:
Disclosed is a semiconductor memory device, in which the refresh period of a fail cell or cells is set so as to be shorter than that of the normal cells, comprises a control circuit for exercising control in such a manner that, if, when refreshing the cell of a first address, generated responsive to a refresh command, with an input control signal being of a first value, a second address, differing as to the value of a predetermined bit from the first address, is determined to correspond to a fail cell, based on the information ore-programmed in a refresh redundant ROM, the cell of the second address is refreshed, and also in such a manner that, if, with the input control signal of a second value, the second address, differing as to the value of a predetermined bit from the first address, is determined to correspond to a fail cell, based on the predetermined information, only the cell of the second address is refreshed, without refreshing the cell of the first address, generated responsive to the refresh command.
摘要:
A DLL circuit includes a coarse delay adjustment circuit and a fine delay adjustment circuit, which further includes a first fine delay circuit and a second fine delay circuit serving as an interpolation circuit. The coarse delay adjustment circuit delays a reference clock signal by a plurality of delay stages so as to provide the first fine delay circuit with two phase signals having the phase difference of two delay stages, which are then converted into two delay signals having the phase difference of one delay stage. The delay signals are subjected to interpolation, thus producing an output clock signal. Due to a reduction of the phase difference in the first fine delay circuit, it is possible to reduce the minimum operation cycle of the interpolation circuit and to thereby increase the maximum operation frequency of the DLL circuit.
摘要:
A paper feeder comprises an acquiring device, a driving roller, driven rollers, a driven roller supporter, a driver, and a controller. The acquiring device acquires thickness information on a sheet of paper. The driving roller rotates by being supplied with torque. The driven rollers rotate with the driving roller when in compressive contact with the driving roller. The driven roller supporter so supports the driven rollers that each of them can rotate under a different rotational load. The driver changes the position of the driven roller supporter relative to the driving roller. The controller selects one of the driven rollers on the basis of the thickness information and so activates the driver as to bring the selected roller into compressive contact with the driving roller.
摘要:
A timing control circuit DLY1 receives clock signal CKa with period T1 and activation signal ACT and outputs fine timing signal FT with delay of m*T1+tda measured from the clock signal where m denotes a non-negative integer and tda denotes delay in the analog delay element. The timing control circuit DLY1 comprises a coarse delay circuit CD and a fine delay circuit FD. The coarse delay circuit CD comprises a counter for counting a rising edge of the clock signal CKa after receiving activation signal ACT and outputs coarse timing signal CT with delay of m*T1 measured from a rising edge of the clock signal CKa. The fine delay circuit FD comprises a plurality of analog delay elements and outputs fine delay timing signal FT with delay of tda measured from the coarse timing signal CT. Variation in delay of timing signal is reduced.