Abstract: An image forming apparatus of the present invention includes a casing, an image forming unit, and an air conditioning device. The image forming unit includes a case accommodating at least a photoconductive element therein and formed with an opening for image transfer via which the photoconductive element is partly exposed to the outside. The opening is the only opening that might allow substances harmful to image formation into the case when the image forming unit is mounted to the casing. The air conditioning device removes the harmful substances flowing into the image forming unit from the outside.

Abstract: An image forming apparatus of the present invention uses a highly viscous, dense developing liquid consisting of a carrier liquid and toner dispersed therein. A developing unit includes a developer carrier and a coating member for coating the developing liquid on the developer carrier. The developer carrier conveys the liquid to a developing zone where it faces an image carrier to thereby develop a latent image formed on the image carrier with the liquid. In the developing zone, the toner in the liquid, which faces the image of the image carrier, is caused to move toward the image by electrophoresis to thereby form a toner layer in which the toner is present in the carrier liquid and a carrier layer in which the toner is absent in the same. When the developer carrier and image carrier moved away from the developing zone part from each other, the toner is caused to move toward the image over a degree at which the developing liquid can separate at the boundary between the toner layer and the carrier layer.

Abstract: A removal nip having a predetermined width is formed by a sweep roller pressurizing mechanism, which adjusts the length of a tension spring by rotating an adjustment screw, and adjusting the size of an energizing force of a sweep roller with respect to a photosensitive drum. A pressurizing mechanism similar to the sweep roller pressurizing mechanism is also provided in a developing roller, to adjust the energizing force of the developing roller, to thereby form a developing nip having a predetermined width.

Abstract: A developing device of the type using a developing liquid and applicable to an image forming apparatus includes a developing roller and a sweep roller. The developing roller is pressed against a photoconductive drum to thereby form a nip. The sweep roller is positioned downstream of the nip in the direction of rotation of the drum and pressed against the drum in such a manner as to sandwich a developed toner layer. The surface of the sweep roller moves at substantially the same speed as the surface of the drum. A bias voltage (250 V) close to the surface potential (100 V to 200 V) of the toner layer formed on the drum is applied to the sweep roller. The bias causes the sweep roller to attract stray excess toner present on the background of the drum after development, thereby preventing a toner image from being blurred.

Abstract: An excess toner removal area is made broader over the whole area with respect to a developer applied area that is broader than an image effective area. Thereby a liquid developer, that tends to spread slightly broader than the applied area after being applied to a photoreceptor drum, is removed by a sweep roller that can sweep excess toner present in an area broader than the original applied area and an excess toner remaining area is then prevented from being formed on the photoreceptor drum. Accordingly, the excess toner on the latent image carrier is removed as much as possible, and a transfer medium and peripheral members are prevented from being soiled due to residual excess toner.

Abstract: A tandem image forming device for an image forming apparatus of the present invention includes a plurality of image forming means arranged side by side along an intermediate image transfer belt. The image forming means each include a developing device and a cleaning device arranged around an image carrier. One of nearby image forming means has its cleaning devise positioned above the developing device of the other image forming means, e.g., an agitating section forming part of the image forming means. This configuration insures smooth circulation of a developer and therefore obviates an irregular developer distribution while reducing the overall size of the image forming device.

Abstract: A developing device of the type using a developing liquid and applicable to an image forming apparatus includes a developing roller and a sweep roller. The developing roller is pressed against a photoconductive drum to thereby form a nip. The sweep roller is positioned downstream of the nip in the direction of rotation of the drum and pressed against the drum in such a manner as to sandwich a developed toner layer. The surface of the sweep roller moves at substantially the same speed as the surface of the drum. A bias voltage (250 V) close to the surface potential (100 V to 200 V) of the toner layer formed on the drum is applied to the sweep roller. The bias causes the sweep roller to attract stray excess toner present on the background of the drum after development, thereby preventing a toner image from being blurred.

Abstract: An image forming apparatus having an improved developer density detecting device for detecting density of a liquid type developer without using an optical sensor. Density of the liquid type developer is detected based upon viscosity of the liquid type developer, which is obtained by sensing pressures, for example, of the liquid type developer sent by a pump and flowing through a developer circulating pipe and applying pressure data obtained by sensing pressures to a predetermined formula. The viscosity can also be obtained by dropping a steel ball, or moving a steel ball, through the liquid type developer and measuring an induced current in a coil based on movement of the steel ball. The viscosity can also be obtained by measuring torque of a device rotating with the liquid type developer.

Abstract: An image forming apparatus having an improved developer density detecting device for detecting density of a liquid type developer without using an optical sensor. Density of the liquid type developer is detected based upon viscosity of the liquid type developer, which is obtained by sensing pressures, for example, of the liquid type developer sent by a pump and flowing through a developer circulating pipe and applying pressure data obtained by sensing pressures to a predetermined formula. The viscosity can also be obtained by dropping a steel ball, or moving a steel ball, through the liquid type developer and measuring properties based on movement of the steel ball. The viscosity can also be obtained by measuring torque of a device rotating with the liquid type developer.

Abstract: In an image forming apparatus, a developing device develops an electrostatic latent image formed on an image carrier with a developing liquid to thereby produce a corresponding toner image. The toner image is transferred from the image carrier to an intermediate transfer body. To increase a transfer ratio from the intermediate transfer body to a paper or similar recording medium, charge applying device applies to the toner image transferred to the intermediate transfer member a charge identical in polarity with toner particles forming the toner image. A roller member faces the surface of the intermediate transfer body to which the toner image is transferred for cleaning the transfer body and removing a carrier liquid. The roller member also controls the amount of carrier liquid on the intermediate transfer body.

Abstract: A developing device for an image forming apparatus of the present invention is capable of enhancing image quality by making the thickness of a film of developing liquid on a photoconduct element uniform after development. Development is effected under particular conditions matching with, e.g., the properties of the developing liquid.

Abstract: An image recording method using a reversible thermosensitive recording material which is capable of assuming a transparent state when heated to a first temperature which is above room temperature, and a colored state when heated to a second temperature which is higher than the first temperature and then cooled, and a heating element, including the step of applying energy to the heating element for generating heat in such a manner as to form each picture element of an image to be formed in the recording material by a plurality of energy pulses applied thereto. An image recording apparatus for this image recording method is also described, which includes a pulse division device for dividing the energy to be applied to the heating element into the plurality of energy pulses, an ambient temperature measurement device for measuring the ambient temperature around the recording material, and a pulse-generation timing adjustment device for adjusting the timing for the generation of the plurality of energy pulses.

Abstract: An apparatus which forms a discharge electric field in order to discharge an object. The apparatus includes an electrode member facing and separated by a preselected gap from the object, and a power source which applies a discharge voltage to the electrode member to thereby cause discharge to occur between the object and the electrode member. Further, the electrode member at the gap includes a material selected in association with the gap so that a functional relationship between the discharge voltage and a discharge current caused by the discharge voltage is a continuous function.

Abstract: In an image forming apparatus, a fixing device fixes a toner image transferred to a sheet, but held in an unstable state, temporarily on the sheet by a Johnson Rahbeck effect. The fixed image firmly adhere to the sheet and is free from disturbance or suffers from a minimum of disturbance.

Abstract: A wet process image forming apparatus using a developing liquid consisting of a carrier liquid and a toner dispersed therein, in which air containing carrier vapor produced in, e.g., a fixing section, is sucked by a suction fan via a first duct into a liquefying section. The liquefying section liquefies the carrier vapor and water vapor. A separating section is disposed below the liquefying portion and includes a receptacle. A liquid produced by the liquefying section is caused to flow down into the receptacle along a chain due to its own weight. The separating section separates the liquid into the carrier liquid and water on the basis of a difference in specific gravity. Only the carrier overlying the water in the receptacle is fed to a carrier tank via overflow ports formed in the wall of the receptacle. The water is delivered to a water tank via a pipe. The pipe is so configured as to maintain the liquid level in the receptacle substantially at the level of the overflow ports.

Abstract: A wet-type image forming apparatus produces a high-quality toner image by condensing a toner image on a photosensitive drum and adhering the toner image onto the photosensitive drum without contacting a liquid carrier applied on the photosensitive drum. The photosensitive drum carries a latent image formed thereon. The toner image is formed by developing the latent image by using a developing liquid including the liquid carrier and toner dispersed in the liquid carrier. An excessive amount of liquid carrier on the photosensitive drum is removed after the toner image is formed. An electric field is formed which causes a current to flow between an electrically conductive member and the photosensitive drum. An air gap is formed between the liquid carrier on the photosensitive drum and the electrically conductive member so that the current flows through the gap, the liquid carrier and the toner image.

Abstract: A recording method of forming images on a reversible thermosensitive recording material, by bringing a heating element of a thermal head into pressure contact with the reversible thermosensitive recording material, which is capable of assuming a first colored state when heated to a first temperature which is higher than room temperature, and then cooled, and which is capable of assuming a second colored state when heated to a second temperature which is higher than the first temperature, and then cooled, and relatively moving at least one of the heating element or the reversible thermosensitive recording material, wherein the stress exerted on the reversible thermosensitive recording material per unit area thereof, .sigma.(g/cm.sup.2), which is generated by the pressure contact of the heating element with the reversible thermosensitive recording material and the relative movements of the heating material and the reversible thermosensitive recording material, is represented by formula (I):.sigma..ltoreq.

Abstract: A recording apparatus for recording data in a thermosensitive recording medium. The recording medium has a reversible thermosensitive recording material capable of selectively assuming one of two visible states, e.g., a cloudy state and a transparent state or a colored state and a decolored state when heated. The thermosensitive material is applied to a sheet of resin. The apparatus surely erases data written in the medium with no regard to the time elapsed and the number of times that data has been repetitively written. The cloud density or the color density is prevented from changing with no regard to the storage temperature, the time elapsed, or the number of times of writing, thereby preventing image quality from being degraded. In addition, the medium has a long service life.

Abstract: An apparatus for recording data in a thermosensitive recording medium at a first temperature after erasing data written in the medium at a second temperature. The apparatus desirably erases data stored in a recording medium with no regard to the time elapsed after writing, condition of storage, writing conditions, the number of repetitive writing and erasing operations, etc.

Abstract: A resistive sheet thermal transfer printer includes a printing head having m (m is an integer) recording electrodes and a common electrode both-in contact with a resistance layer of an ink sheet, the m recording electrodes being arranged in a line, and being separated from the common electrode by a predetermined distance, where m is an integer, a driving circuit for applying a driving voltage across the common electrode and one or plurality of recording electrodes selected from the m recording electrodes in accordance with printing data supplied from an external unit, a controller for controlling the driving circuit, when the driving voltage is simultaneously applied across the common electrode and selected successively arranged recording electrodes, so that an amount of driving voltage applied across the common electrode and an end recording electrode positioned at an end of the selected successively arranged recording electrodes is less than an amount of driving voltage applied across the common electrode a