Abstract: A method of detecting the toner density of a standard test toner image which comprises the steps of forming on the photosensitive drum a saturated test toner image from which the amount of diffused light is to be measured as a saturation level as well as the standard test toner image, and evaluating the measurement of the amount of diffused light from the standard test toner image in accordance with the measurement of the amount of diffused light from the saturated test toner image. In an image forming method or image forming apparatus which employs this toner density detecting method, the standard test toner image is formed on the photosensitive drum with a specified voltage of developing bias impressed, and an optimum developing bias voltage is calculated from the measurement of the amount of diffused light from the saturated test toner image and the measurement of the amount of diffused light from the standard test toner image. Such a process is carried out prior to an image forming operation.

Abstract: A digital color copying apparatus for forming a color copy in which an arbitrary color in a color original image is replaced by a desired color comprises bar codes for determining whether the desired color is a color in the original image or a color in the copy image and designating the desired color, and a bar code reading pen. When the bar code reading pen reads the bar codes, it is determined whether the designated color is a color in the original or not and the color is definitely specified.

Abstract: An exposure control system includes (a) a first detecting unit for detecting the original image density of an original document and producing a first signal variable with the detected original image density, (b) a control unit for regulating the quantity of light with which the image-carrying document is to be irradiated by the exposure lamp, the quantity of light being regulated on the basis of the signal from the first detecting unit, (c) a reference pattern located to be irradiated with light from the exposure lamp, (d) a second detecting unit for detecting the visualized image density of the reference pattern and producing a second signal variable with the detecting visualized image density, (e) a modifying unit for modifying the quantity of the light from the exposure lamp so that the value represented by the second signal falls within a predetermined range, and (f) a correcting unit for correcting the quantity of light controlled by the control unit, so that the controlled quantity of light is corrected

Abstract: An image forming apparatus of a visible image transfer type provided with a standard pattern which is disposed at a position where it can be illuminated by a lamp for illuminating an original, a first sensor for detecting the density of the original and a second sensor for detecting the density of a visible image of a standard pattern. The light amount of the lamp is varied so as to make the density of the visible image detected by the second sensor fit a fixed value or fall within a fixed range, and is designated as a corrective data. The light amount of the lamp, which corresponds with the original density, is corrected in accordance with the corrective data by shifting a characteristic curve which shows the relation between the density of the original and the light amount of the lamp used for the original density measurement.

Abstract: A multi-functional imaging apparatus being operable in either one of various office automation modes such as copy mode, facsimile mode, printer mode and the like is disclosed. The multi-functional imaging apparatus is comprised of an image reading section, an image forming section and a communication section for transmitting and receiving image data. Plural card-like memory elements are provided for designating individual office automation modes. When a desirable card-like memory element is set into the imaging apparatus, the apparatus becomes operable in an office automation mode corresponding to the inserted memory element.

Abstract: A deflection yoke for a picture tube of a projection color television receiver set has a solenoid-shaped auxiliary coil arranged adjacent to a core of the deflection yoke with a center axis of the auxiliary coil being aligned to a center axis of the deflection yoke. A vertical deflection current or a horizontal deflection current is supplied to the auxiliary coil. An electron beam is deflected by a magnetic field generated by the current of the auxiliary coil so that a raster formed on a face plate of the picture tube is deformed. The raster is deformed to such an extent that it has a correct shape when it is projected on a screen.

Abstract: A projection color television receiver set comprises three picture tubes juxtaposed to one another and producing red, green and blue light images which are projected through respective lenses onto a single screen to be reproduced as a single synthesized color picture. In order that rectangular rasters produced by the picture tubes disposed at both sides of the center picture tube are prevented from being deformed into trapezoidal rasters when projected on the screen, deflecting yokes used in the lateral picture tubes are provided with horizontal deflection winding in such arrangement that trapezoidal rasters are produced on faceplates of the laterally disposed picture tubes, respectively, which rasters are projected in a rectangular form on the single screen in alignment with the rectangular raster produced and projected from the center picture tube, whereby a color picture of an improved quality is reproduced on the screen, involving substantially no misconvergence.