摘要:
Apparatus for measuring developer density comprising, a container containing a developer constituted by a toner and a carrier, a rotary member agitating the developer in the container with its rotation, a transparent detection window facing the container, and having an electrically conductive film on its surface facing the developer, a measuring section measuring developer density in container on the basis of reflected light from developer illuminated through the detection window, an electrode which is supported by the rotary member, and is rotated together with the rotary member such that a gap between the electrode and the detection window is maintained at a predetermined value, the electrode being made, at least at one portion facing the detection window, of electrically conductive material, at least one magnet which is supported by the electrode, retains the developer, so that the magnet makes the developer to be brought into contact with the detection window with rotation of the rotary member, and a bias application member for applying bias between the detection window and the electrode so as to make the detection window and the toner electrically repulsive to each other.
摘要:
An image forming apparatus for forming images by an electrophotographic process. The image forming apparatus includes a humidity sensor for detecting the humidity in the area around the image forming members provided therein, a density sensor for detecting the density of images formed on a photoreceptor, and a humidity controller having a dehumidifying unit and a humidifying unit for adjusting the humidity in the area around image forming members. The humidity controller is operated according to humidity historical data generated based on the humidity data outputed from the humidity sensor, a detected photoreceptor potential, a detected amount of developer scattered from the developing unit or the detection result from the density sensor.
摘要:
An apparatus for optically measuring toner density, having a rotary member which rotates and retains a developer constituted by a toner and a carrier by magnetic force, a transparent detection window which is disposed at a position where the developer retained on the rotary member rubs said detection window through rotation of said rotary member, a detection device which illuminates the developer through the detection window and detects the amount of reflected light from the developer and the magnitude of variations of the amount in response to rotation of the rotary member, and a warning device which issues an abnormal warning when the magnitude is smaller than a predetermined reference value, and a method for optically measuring toner density by using the apparatus.
摘要:
Apparatus for measuring developer density comprising, a developer agitator section agitating a developer, a rotational conveying member conveying the developer in the developer agitator section with its rotation, a transparent detection window facing the developer agitator section, a plurality of magnets being fixed on the rotational conveying member, and retaining the developer, and causing the developer to be brought into contact with the transparent detection window with a rotation of the rotational conveying member, a density detection section measuring the developer density on the basis of reflected light by illuminating the developer retained on the magnets, and caused to be brought into contact with the detection window, and the magnets including at least one cleaning magnet, and the density detection section is situated in a passage of the developer which is conveyed so as to be circulated through first agitator passage adjacent to a development section and second agitator passage behind the first agitator passage, and between a passage for conveying the developer from the first agitator passage to the second agitator passage and a replenishment opening for replenishing the toner to the second agitator passage.
摘要:
In an electrophotographic image forming apparatus, a correction coefficient corresponding to each density level of toner consumption of a developing device is determined in accordance with a selected tone correction method, and/or the ratio of the emission period to the non-emission period of a light source. A toner consumption calculator multiplies the correction coefficients by the number of pixels of each density level of document image data, and determines the amount of toner consumed by the developing device from the sum total value of the multiplication results determined for each density level. A toner replenishment device resupplies toner to the developing device based on the determined amount of consumed toner. As a result, a constant toner concentration Tc normally can be maintained because toner is resupplied based on the calculated amount of toner consumption.
摘要:
An image forming method and an image forming apparatus in which a plurality of kinds of toner images are supported on an image support member, the method comprising the steps of: forming, on the basis of first image data, a first toner image on the image support member with first toner; detecting the first toner image so as to output a detection signal; forming, on the basis of second image data, a second toner image on the image support member with second toner which is different from the first toner; and executing, by an output of the detection signal, a program for setting conditions for forming the second toner image.
摘要:
An electrophotographic image forming apparatus for forming a color toner image by a developing device and fixing the toner image by a fixing device including top and bottom rollers. When OHP mode for forming images on transparency sheets is selected, the time required for fixing the toner image is prolonged so as to assure the transparency of the image fixed to a recording member. That is, if the size of the transparency sheet is larger than a predetermined value, the transparency sheet is sent to a returning path which returns the recording member discharged from the fixing device to the fixing device again, and if the size of the transparency sheet is smaller than the predetermined value, the fixing device is operated more slowly than a case of forming images on non-transparency sheets. Further, when the OHP mode is selected, heating power is supplied to both top and bottom fixing rollers, and when the OHP mode is not selected, the heating power is supplied to the top fixing roller only.
摘要:
An image forming apparatus which comprises a photoreceptor medium supported for rotation in one direction, a charging device for forming an electrostatic latent image on the photoreceptor medium, a plurality of developing devices disposed in fact-to-face relationship with the photoreceptor medium for developing the electrostatic latent image into a visible powder image, a transfer charger for transferring the powder image onto a copying sheet, a sheet transport system for supplying the copying sheet to a transfer station where the transfer charger is dispose, a detector for detecting the color of toner material contained in each of the developing devices, and a control circuitry for causing one of the developing devices to apply the toner material of a particular color to a portion of the photoreceptor medium, which corresponds in position to a leading edge of the copying sheet, in the event that such one of the developing devices is detected as containing the toner material of that particular color.
摘要:
Copying apparatus is provided in which outline copying for only a designated area of an original image can be easily selected. An area for the outline copying can be designated and images inside and outside the designated area can be copied in different colors. The arrangement includes a plurality of keys for designating an area of an original image to be copied and a scorotron charger for causing a potential in areas other than the outline portions of an electrostatic latent image, formed on a photoreceptor drum, to be substantially equal to a potential in an area containing the image. An eraser unit is provided for erasing the charge in an area where development is not required and a developing device develops the electrostatic latent image. A transfer charger is provided for transferring the image developed by the developing device onto copying paper. When an area of the original images designated and an outline image forming mode is selected by the operator of the machine, two copy operations are performed to composite an outlined image formed inside or outside the designated area and a normal image formed in the area which does not include the outline image so that a composite image is copied onto the copy paper.
摘要:
Developer density measuring apparatus comprising a transparent detection window confronting the interior of a developing device, illumination means for illuminating developer comprising a toner and a carrier accommodated in said developing device, and density determining means for determining developer density by the amount of light reflected from said developer measured through said transparent detection window, and wherein the surface of the transparent detection window on the side confronting the interior of the developing device is roughened.