Sharp Kabushiki Kaisha Corporation

Toshiaki Kagawa

Shogo Yokota

Tetsunori Mitsuoka

Hiroshi Kida

Toshihiro Tamura

Takashi Yamanaka

Tomohiro Maeda

Kenji Asakura

Katsumi Adachi

Takashi Mukai

Taisuke Kamimura

Toyoaki Nanba

Masashi Hirai

Hiroyuki Yamaji

Shinji Yamana

Tohru Sakuwa

Hiroyuki Sawai

Kouji Shinkawa

Hiroshi Doshohda

Hiroshi Ishii

Susumu Murakami

Hiroyuki Kageyama

Atsushi Ide

Hideki Ohnishi

Kouji Yamaji

Atsuyoshi Nakayama

Syougo Yokota

Masanobu Deguchi

Masaru Tsuji

Yoshinobu Tateishi

Yoshiaki Masuda

Tatsuya Shinkawa

Hiroaki Hori

Shinichi Azumi

Yoshiya Kinoshita

Masaaki Ozaki

Kazuhiko Furukawa

Hiroshi Doshoda

Atsushi Kadoya

Shoutaro Okamoto

Tatuya Shinkawa

Syogo Yokota

Hisasi Atarasi

An image forming apparatus is provided. The image forming apparatus includes an image forming section, an intermediate transfer section, a secondary transfer section, a fixing section, a power source, a voltage detection section, a temperature detection section, and a fixing section control circuit. The fixing section control circuit includes a switching control section, a voltage judgment section, a temperature judgment section, and a preparation control section. When the switching control section switches the current conduction state to the heat source and the driving section from an off conduction state to an on conduction state and the voltage judgment section judges to be less than a threshold voltage, the preparation control section controls the preparation operation of the heating section such that the switching control section continues the on conduction state over a given idle time after the temperature judgment section has judged to be a preset temperature or higher.

Image forming apparatus

A fixing device includes a fixing portion provided with a fixing roller, a heating roller and a fixing belt; a pressing roller that presses a recording sheet to the fixing belt; a cleaning unit provided with a cleaning web that cleans up the pressing roller; and a contact/separation mechanism that separates fixing means from the pressing roller. Viscosity of silicone oil that impregnates the cleaning web is set to 3,000 cs or more, and the contact/separation mechanism separates the fixing belt from the pressing roller at the time of rotation operation before fixation.

Fixing device and image forming apparatus using the same

First, a first temperature difference and a second temperature difference are calculated. The first temperature difference is a difference between (a) a first detected temperature that is a current temperature of the fixing member and (b) a difference of a control target temperature for the fixing member. The second temperature difference is a difference between (a) the first detected temperature and (b) a past temperature of the fixing member which past temperature was detected a predetermined time earlier than the current time. Then, by reading out, from a table prepared in advance, an amount of power to be supplied to a heating member which amount corresponds to a combination of the first temperature difference and the second temperature difference, the amount of power to be supplied to the heating member is determined. In accordance with this amount of power determined, an actual amount of power supplied to the heating member is controlled. This makes it possible to simply and effectively suppress a temperature ripple of the fixing member.

Fixing device, image forming apparatus, and temperature control method for fixing device

A laser fixing device, which is for use in an electrophotographic image forming apparatus, including: a carrying device for carrying a sheet; and a laser array section which is made up of a plurality of laser sources arrayed in a line, the plurality of laser sources irradiating a non-fixed toner image, which is attached to the sheet that is being carried by the carrying device, with a laser beam so that the non-fixed toner image is fused and fixed to the sheet. In the laser fixing device, an irradiation region length and a sheet carrying speed are set so that tn&#x2267;0.259&#xb7;mt, where mt is a maximum level of an attached-toner amount per unit area of the sheet (mg/cm) in the image forming apparatus, and tn is an irradiation region crossing time (msec), which is found by dividing the irradiation region length by the sheet carrying speed, the irradiation region length being a length, in the direction in which the sheet is carried, of a region on the sheet which region is irradiated with the laser beam. According to this configuration, it is possible to prevent a void from occurring in the laser fixing device.

Laser fixing device

A fixing device of this invention includes: a fixing belt; a heating member for heating the fixing belt; a retaining member having (i) a convex surface which is curved and is in contact with an inner surface of the fixing belt and (ii) a flat surface which is opposite to the convex surface; and a ceramic heater provided on the flat surface of the retaining member. Therefore, the fixing device of this invention is excellent in safety and is capable of reducing a warm-up time.

Fixing device and image forming apparatus including the same

A fixing device of the present invention includes: an external heating belt which is to contact with a surface of a fixing roller so as to heat up the fixing roller; and a cleaning member (a scraper and/or cleaning pad) which is to contact with the external heating belt. The cleaning pad which is impregnated with silicone oil is to contact with a surface of the external heating belt, thereby applying the silicone oil (release agent) to the surface of the external heating belt. This makes it possible to prevent generation of an offset.

Fixing device and image forming apparatus having same

An image recording medium that can be repeatedly used by removing the toner image has a three-layered structure formed of a heat-resistant resin sheet and a pair of releasing and light absorptive layers coated on both sides of the heat-resistant resin sheet. The releasing and light absorptive layer generates heat by absorbing laser so as to fuse and fix the toner image formed on the special sheet surface at the time of image forming, and assures pertinent releasing performance at the time of image removal so as to facilitate removal of the re-fused toner image. Each releasing and light absorptive layer may be split into a light absorptive layer and a releasing layer. The heat-resistant resin sheet may be produced by adding an infrared absorbent to a heat-resistant resin sheet to serve as a heat-resistant sheet and a light absorptive layer.

Image recording medium, image recording medium reusing apparatus, image forming apparatus using the same and image recording medium reusing method

A fixing device having a fixing belt which satisfies 42.2&#x2267;ER&#x2267;0.1044&#xd7;D&#xd7;&#x3bc;, where: D represents an inner diameter of the fixing belt; A represents a second inner diameter of the fixing belt; ER represents an elongation rate of the fixing belt and is formulated as ER=(A&#x2212;D)/D&#xd7;100; and &#x3bc; represents a coefficient of kinetic friction between the fixing belt and the fixing roller. The fixing device is thus arranged so that the fixing belt is driven by the fixing roller to rotate in a state where the pressing roller is separated from the fixing belt. This makes it possible to lengthen a life of a fixing belt, to shorten a warm-up time, and to reduce power consumption in a fixing device using a belt fixing method.

Fixing device having an endless fixing belt and two-position disjunction mechanism

In a fixing device including (i) an external heat belt which abuts against a surface of a fixing roller so as to heat the fixing roller and (ii) a cleaning member which abuts against the external heat belt, a fixing temperature, which is a surface temperature of the fixing roller during a fixing process, is set per group into which recording media to be subjected to the fixing process are divided according to their widths in a direction of a rotary axis of the fixing roller, in such a way that the fixing temperature is set to a lower temperature for a group of narrower widths. This makes it possible to prevent a reduction in releasability of the fixing roller caused by a material, which is scraped off from the external heat belt by the cleaning member and then adhered to the fixing roller, thereby preventing the high-temperature offset.

Fixing device, image forming apparatus, and method for controlling fixing device

A color multifunction printer of the present invention includes a volatile chemical substance catching device, provided in an exhaust duct provided above a fixing unit, which generates an electric field in an atmosphere with use of an electric-field generating and catching member, which attracts volatile chemical substances contained in the atmosphere to a surface of the electric-field generating and catching member by the action of the electric field, and which catches the volatile chemical substances. This makes it possible to realize a volatile chemical substance catching device and an electronic apparatus that hardly suffer from aged deterioration in performance and can catch volatile chemical compounds such as VOCs and odors over a long period of time.

Volatile chemical substance catching device and electronic apparatus

In a fixing device including a fixing roller, a pressure roller and an external heating section, a scraper is arranged to contact a circumferential surface of an external heating belt and scrape toner and the like on the circumferential surface to thereby clean the circumferential surface. In addition, a material that has higher adherence to toner than on a circumferential surface of the fixing roller is used for the external hating belt to thereby peel the toner and the like on the circumferential surface of the fixing roller and clean the circumferential surface of the fixing roller. Further, as a vibration applying section adapted to apply vibration to the scraper, a first contact/separation section adapted to contact/separate the external heating section with/from the fixing roller is provided. Vibration is applied to the scraper by the first contact/separation to peel the toner and the like off the scraper.

Fixing device with cleaning section for image forming apparatus

A fixing apparatus includes a heating element with an NTC characteristic in which an electric resistance value decreases as a temperature increases, which extends (i) in a direction parallel to a recording paper and (ii) in a width direction perpendicular to a carrying direction of the recording paper, and which has a longer length, in the width direction, than a width of the recording paper. The fixing apparatus further includes electrode sections provided in close proximity to both ends of the heating element in the width direction), the electrode sections being connected to the heating element, so that a current flows in the heating element in a direction substantially perpendicular to the carrying direction of the recording paper. This makes it possible to restrain excessive increase in temperature at the both ends of the heating element and to obtain a uniform temperature distribution.

Fixing apparatus having heating element and image forming apparatus having the fixing element

A fixing device includes a fixing belt for fixing an unfixed toner image onto a recording medium, a planar heating member for heating the fixing belt, and a pressure roller. The heating member includes a ceramic heat generating element having a PTC characteristic, and a high-thermal-conductive heat diffusion member. The fixing belt is formed in an endless shape and is supported around, at least, the high-thermal-conductive heat diffusion member, thereby to be heated. The ceramic heat generating element comes into contact with the fixing belt over the full width thereof with the high-thermal-conductive heat diffusion member interposed therebetween. The high-thermal-conductive heat diffusion member comes into contact with the fixing belt over the full width thereof and diffuses heat generated by the heat generating element, in the traveling direction of the fixing belt.

A planar heat-generating bodyof a fixing apparatus of the present invention includes (i) a resistive heat-generating bodycontaining small heat-generating bodies electrically connected in parallel and aligned in a direction perpendicular to a direction in which a fixing beltmoves and (ii) a PTC element and a corresponding small heat-generating body being provided to be connected in series with a power source, the PTC element having a resistance value increasing at a predetermined temperature or higher. The PTC elementand the small heat-generating body are provided in an area corresponding to a non-sheet passing area of the fixing belt, the non-sheet passing area being an area where a smallest-size sheet does not pass, the smallest-size sheet being smallest among sheets that the fixing apparatus deals with. This allows for prevention of a temperature increase in the non-sheet passing area with a simple arrangement.

Fixing apparatus having an enhanced planar heat generating body, and image forming apparatus including the same

A fixing device of the present invention is arranged so that: (i) at least both ends of a planar heat-generating member come close to or touch an outer surface of a fixing roller, said both ends being in a circumferential direction when viewed in an axial direction of the fixing roller; and (ii) the planar heat-generating member has, in the vicinity of both the ends, shapes formed gently with respect to the outer surface of the fixing roller when viewed in the axial direction. An almost whole inner surface area of the fixing belt wound around the planar heat-generating member and the fixing roller touches the planar heat-generating member or the fixing roller. The fixing belt is naturally formed, without being distorted at an area where the fixing belt touches the heating member. This allows a fixing device using a planar heat-generating belt type fixing method, which provides a short warm-up time, to be excellent in heat efficiency, consume less power, and have a fixing belt which does not slip easily.

Growing community of inventors

Nara, Japan

Toshiaki Kagawa