Abstract: An image forming apparatus for executing image forming process on a page by page basis including: a toner image forming section for producing a visible image formed of toner as a toner image on an image carrier; a transfer section which performs a transfer process for transferring the formed toner image onto a recording medium; a cleaning section which removes toner remaining on the image carrier after the transfer process; a waste toner storing section in which the removed toner is accumulated; and a waste toner amount detecting section which detects an amount of the toner accumulated in the waste toner storing section on the basis of at least three detection levels.

Abstract: A cleaning member for cleaning the toner remaining on the outer peripheral surface of a heat roller that fixes an unfixed developer image formed on a sheet of paper onto the paper by heating under pressure, includes: a mesh portion having a predetermined mesh in the area abutting the heat roller. The mesh portion is formed of heat resistant wires.

Abstract: A timer clocks and accumulates time periods during each of which a recording sheet is transported or transfer bias is applied as transfer execution periods. When the accumulated value reaches a predetermined value, the timer outputs a time-up signal to a CPU and then clears the accumulated value. The CPU executes a cleaning operation at the time the time-up signal is inputted from the timer. In the cleaning operation, the CPU causes a high-voltage power source to apply cleaning bias to a transfer electrode roller while causing a high-voltage power source to apply delivery bias to an auxiliary cleaning roller, in order to return toner attracted to the auxiliary cleaning roller to a photosensitive drum via a transfer belt.

Abstract: An image forming apparatus includes a history storage portion for storing the usage history involving the number of prints of the image forming apparatus, and a processing time controller for changing the time of the pre-processing operation before or the time of the post-processing operation after a printing process of the printing portion, based on the stored usage history so as to exclude the influence of the unfixed developer on the printing process.

Abstract: An image forming apparatus includes an endless belt stretched over a plurality of rollers. The apparatus also includes a potential detecting device for detecting a potential of the endless belt. The detecting device is positioned downstream, along a sheet transport path, of a transfer position where the belt has direct contact with the image bearing member. The apparatus further includes a transferring member for transferring a toner image formed on the image bearing member to a sheet. An image forming process is halted when the potential detecting device does not detect a change in potential caused by presence of a sheet on the endless belt.

Abstract: An image forming apparatus of the present invention carries out an image processing with respect to a sheet size based on a print request and image information based on the print request, so as to obtain a write image on a photoreceptor. On the basis of a printing ratio of the write image obtained by the image processing, the image forming apparatus predicts the occurrence of an image elongation. If the image forming apparatus predicts that the image elongation occurs, the image forming apparatus calculates a bending amount of a bended portion on the basis of the difference between the peripheral velocity of a photoreceptor and the peripheral velocity of the idle roller, and the image forming apparatus variably controls the peripheral velocity of an idle roller so that the bending amount calculated is adjusted so as not to cause a slip phenomenon.

Abstract: A combined resistance R1=Vt1/I1 (MO) of a transfer belt (61) and a recording sheet obtained when a transfer current I1 (?A) passes through the transfer belt (61) and the recording sheet upon application of a first transfer bias voltage Vt1 (V) to a transfer roller (6b) from a high-voltage power source (6f) and a combined resistance R2=Vt2/I2 (MO) of the transfer belt (61) and the recording sheet obtained when a transfer current I2 (?A) passes through the transfer belt (61) and the recording sheet upon application of a second transfer bias voltage Vt2 (V) to the transfer roller (6b) from the high-voltage power source (6f), are established to have the relationship: R2/R1=7?(I2)?0.5 therebetween.

Abstract: 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.

Abstract: An image forming apparatus of the present invention carries out an image processing with respect to image information, requested to be printed, so as to obtain a write image which is to be written on a photoreceptor. Then, the image forming apparatus predicts the occurrence of an image elongation and specifies an image elongation occurring area on the basis of a printing ratio of the write image which is subjected to the image processing as above. If the occurrence of the image elongation is predicted, the amount of the image elongation occurring area to be shortened is calculated on the basis of the amount of the image elongation occurring area lengthened. The image forming apparatus carries out the image processing again so as to obtain the write image whose image elongation occurring area is shortened in accordance with the amount of the image elongation occurring area to be shortened. Finally, a process of printing the write image obtained as above is carried out.

Abstract: An image forming apparatus of the present invention predicts the occurrence of an image elongation, in other words, predicts that an image transferred is lengthened on a sheet due to slipping of the sheet with respect to a photoreceptor at a transfer nip portion. If the occurrence of the image elongation is predicted, the amount of a rear edge portion to be deleted from an electrostatic latent image is obtained on the basis of a sheet rear edge void setting change table, the amount of the rear edge portion to be deleted is added to the default amount of a rear edge void, a portion corresponding to the rear edge portion of an image of image information is deleted, and a printing process is carried out. In this way, even if a slip phenomenon occurs, in other words, the sheet slips with respect to the photoreceptor, it is possible to surely secure a blank space at a rear edge portion of the sheet.

Abstract: A sheet conveying device that facilitates solution of a jam of a sheet and which is capable of inhibiting shortening of life due to a jam is provided. A sheet having a bent leading end that is very likely to jam is positively made to jam at a blocking portion formed on an upstream side of an image forming station in a sheet conveying direction thereof. Consequently, it is possible to more easily perform an operation of solving a jam than in a case where a jam of the sheet occurs in the image forming station. Moreover, it is possible to prevent deterioration of the image forming station due to a jam, and inhibit shortening of the life of the image forming station resulting from a jam.

Abstract: An image forming apparatus includes an endless belt stretched over a plurality of rollers. The apparatus also includes a potential detecting device for detecting a potential of the endless belt. The detecting device is positioned downstream, along a sheet transport path, of a transfer position where the belt has direct contact with the image bearing member. The apparatus further includes a transferring member for transferring a toner image formed on the image bearing member to a sheet. An image forming process is halted when the potential detecting device does not detect a change in potential caused by presence of a sheet on the endless belt.

Abstract: Transfer roller(s) is/are such that either end thereof is formed from fibrous electrically conductive component(s) and such that cylindrical portion(s) in central region(s) is/are, for example, formed from metal roller-like structure(s), either fibrous electrically conductive component outer end being arranged so as to extend somewhat beyond either transfer/transport belt side. Furthermore, outside diameter(s) approximated by tips of respective individual fiber(s) of fibrous electrically conductive component(s) is/are somewhat larger than diameter(s) of metal roller-like structure(s). This makes it possible for electric field(s) to be applied, and for charging to occur, along the full width(s) of transfer/transport belt(s).

Abstract: A sheet P on which an image of a developer is unfixed is recovered from a transfer unit 6 to a sheet recovery portion 64, the sheet P is bent with the surface of the sheet P on which the image of the developer has been transferred facing inward and, while remaining bent, the sheet P drops downward between an outer guide plate 72 and a transfer convey belt 51, then an openable cover 74 is opened to remove the sheet P.

Abstract: An image forming apparatus comprising loop belts each carrying a recording medium is provided. The image forming apparatus forms an image, which is based on obtained image data from the outside, on the recording medium carried by the loop belt. The loop belt is formed by splicing belt members made of different materials in the width direction of the loop belt.

Abstract: An image transfer device includes an image transfer electrode roller which is disposed face to face with a photosensitive drum with a printing sheet passing between the image transfer electrode roller and the photosensitive drum. The image transfer device is structured such that the image transfer electrode roller can be shifted back and forth along a transport direction of the printing sheet. A voltage is applied to the image transfer electrode roller to create an image transfer electric field between the image transfer electrode roller and the photosensitive drum for transferring a toner image formed on the photosensitive drum onto the printing sheet. The image transfer electrode roller is brought to one of different positions along a transport direction of the printing sheet selected according to information on properties of the printing sheet and transfers the toner image onto the printing sheet at that position.

Abstract: A timer clocks and accumulates time periods during each of which a recording sheet is transported or transfer bias is applied as transfer execution periods. When the accumulated value reaches a predetermined value, the timer outputs a time-up signal to a CPU and then clears the accumulated value. The CPU executes a cleaning operation at the time the time-up signal is inputted from the timer. In the cleaning operation, the CPU causes a high-voltage power source to apply cleaning bias to a transfer electrode roller while causing a high-voltage power source to apply delivery bias to an auxiliary cleaning roller, in order to return toner attracted to the auxiliary cleaning roller to a photosensitive drum via a transfer belt.