Abstract: A document reading apparatus comprising a document table, a reading section disposed above the document table for reading a document placed on the document table. The reading section includes a sensor for detecting variations of brightness within a selected reading area of the document which is designated by light beams prior to a reading operation. This apparatus further comprises a display device for displaying the image of the selected reading area.

Abstract: In a focus detection system for detecting focus condition of an objective lens, there is disposed a pair of photo sensor arrays each having a plurality of photo cells lined up in one direction to receive a first image and second image passed through respectively a lens system and the photo sensor arrays produce first original signal groups and second original signal groups each signal groups corresponding to light intensity of the images projected thereto. A processing device processes the original signal groups in such a manner that the first original signal groups are respectively divided into a plurality of blocks, and one of the blocks of the first original signal groups is selected and it is detected that in what group in the selected block best coincidence occurs.

Abstract: An image forming apparatus comprising a charging section for uniformly charging a surface of a photoconductive body; an image forming section for forming an image on the photoconductive body charged by the charging section; a detecting section for detecting an influx current flowing to the photoconductive body when the photoconductive body is charged by the charging section; and a control section for controlling the image forming section so as to stabilize a quality of images formed by the image forming section.

Abstract: A light deflecting device comprising a transparent member having an electro-optical effect, and a first and a second electrode provided on opposite surfaces of the transparent member. When a voltage is applied to one of the electrodes, an uneven electric field is formed inside the transparent member.This uneven electric field varies a refractive index distribution through the transparent member. As a result, light entering the transparent member is deflected inside the transparent member. This light deflecting device may be used in an optical printing head, a rangefinder or a color checker.

Abstract: A multi-beam optical system is provided with reflecting mirrors and separating mirrors on optical paths of light beams for each color so that the difference of the numbers of reflections of the scanned light beams for the respective colors when they penetrate through the lens and reach the photosensitive drum can be the same or an even number. The ference of the number of reflections of the scanned light beams for the respective color can become an even number and the scanning lines are distorted in the same direction by the lens, and are thus not liable to lose a parallel relation between the line images.

Abstract: A zoom lens system for a limited conjugate distance comprises at least three lens units which can be divided into, from an object side to an image side, a front lens group having a positive refracting power and a rear lens group having a positive refracting power. An axial distance between the front lens group and the rear lens group varies by a focusing operation. A zooming operation is performed by one of the front lens group and the rear lens group including at least two lens units. The zoom lens system fulfills the condition of l=m wherein l represents an object focal length of the zoom lens system, and m represents an axial distance between an object point and an object principal point of the front lens group.

Abstract: The present invention provides a compact zoom lens having a zooming ratio of six (6) to eight (8) and an F-number of 1.4 to 1.

Abstract: A compact-size, light-weight, low-cost zoom lens system with high optical quality is achieved by using a ray restrictor placed at the most object side of the zoom lens system. In one type, the ray resistor shifts toward the object at a speed different from that of the most object side lens of the zoom lens system as the zoom lens system is zoomed toward the longest focal length, which effectively blocks harmful rays causing coma flare in the peripheral area. In another type, the aperture diameter of the ray restrictor varies according to a zooming operation. The ray restrictor of any type is especially effective when used in a zoom lens system composed of two lens groups. By introducing one or more aspherical surfaces satisfying a certain condition (or conditions) in the zoom lens system, various aberrations are further favorably corrected.

Abstract: A reader printer is disclosed which incorporates therein a scanning plane mirror for projecting an image in the form of a slit on a sensitive material. The sensitive material is shifted proportionately to the rotation of the scanning mirror so that the position at which the image is projected on the sensitive material will coincide with the scanning position of the sensitive material. As a result, the otherwise possible phenomenon of defocusing is precluded and the image is faithfully reproduced on a recording paper. The mechanism for rotating the scanning mirror and the mechanism for shifting the sensitive material are divided to allow production of a reader printer of a small size.

Abstract: An image projection apparatus which projects an image of a microfilm onto a screen and copies the image. Among a plurality of projection lenses, which are zoom lenses having set-ups of magnifications in correspondence to the sizes of text images and copy paper, a lens with a set-up of the intended magnification is mounted selectively on the apparatus for the operation. When the lens is mounted, it is initialized to a reference magnification regardless of the magnification which has been set, and in this operation the zoom value is memorized. Subsequently, the lens is zoomed by the memorized zoom value in the opposite direction so that the magnification which has been set previously is restored.

Abstract: A recording sheet storing apparatus includes a magazine having a removable cover that is adhered to the surface of the magazine. The magazine can be placed into a recording apparatus and the cover can be engaged with a winding device that can reciprocate to remove the cover member and subsequently to reseal it. A transmission system can apply a driving force to the winding means and a driving force to a carriage which supports the winding device as it moves along the magazine.

Abstract: An image forming system for copiers, printers and the like having a main body which forms images on sheets of paper inserted therein and a plurality of sheet feeding units selectively attachable to the main body. The main body has a timing roller set which transports the papers to an image forming position with an appropriate timing, and each of the sheet feeding units has a paper feeding system with a take-up roller for supplying papers from the unit directly to the timing roller set without intermediate rollers in the main body. The system further includes side and bottom sheet feeding units selectively attachable to the main body and the side unit includes a guide for guiding sheets from the bottom unit into the main body. The system further includes a separate sheet guide mountable on the bottom unit for guiding sheets into the main body when the side unit is absent from the system.

Abstract: A photoelectronic image forming apparatus reproduces an image on the basis of an electrostatic latent image produced on a photo-sensitive body by using a developer containing a toner and a carrier, and comprises a plurality of toner density measuring units for respectively producing outputs each indicative of a toner density of the developer and a toner density determining unit responsive to the outputs for determining an actual toner density so as to precisely control the tone of the image.

Abstract: A light beam scanning optical system having a linear image forming optical system for converging a laser beam from a light source into linear images on the deflection reflecting surface of deflector, and a scanning image forming optical system for causing the laser beam reflected from the deflector to form images on the object to be scanned, wherein said scanning image forming optical system including at least one toric surface and at least one compound lens composed of a positive lens and a negative lens, whereby the object is scanned correctly by the laser beam despite a difference in wavelength between the laser beams used or variations in the wavelength of the beam.

Abstract: An image forming apparatus having a device for forming an image on a copy sheet, an input device for designating a due data, a device for storing the due date designated through the input device and a mechanism for inhibiting an operation of the image forming device after a lapse of the designated due date stored in the storing device. The apparatus, when rented, enables a rental firm to supervise the rented apparatus by preventing an unauthorized or overdue use thereof through a service person who is to regularly visit the user and check the apparatus.

Abstract: A camera system with an auto-focusing system includes a camera body and an interchangeable zoom lens. The interchangeable objective lens stores various data to be sent to the camera body for improving automatic focus adjustment, such as an information necessary to convert the detected defocus information into a movement of the driving power source to carry out the automatic focus adjustment. The driving power source in the camera body is controlled in responses to the data from the interchangeable objective lens and the detected focus information, the driving power being transmitted to the interchangeable objective lens. The camera body is further capable of inhibiting the focus adjustment or focus indication in response to a data from the interchangeable objective lens under an unfavorable condition.

Abstract: An apparatus and method for detecting an image density of an original document is provided. The density of the image of an original document is determined during the changing of the zoom magnification of a zoom lens. A control signal for the image density is then utilized to control an imaging operation.

Abstract: A plurality of image input devices and a plurality of image output devices are connected to a system bus and an image bus of an image processing system through an external device control unit. The image processing system comprises a host CPU, an image processing unit, a CRT and multiple input and output devices, which are connected with each other through the system bus and the image bus. The external device control unit comprises a control CPU for controlling various processing based on various commands, a switch connected to each of the image input/output devices and to the image bus for switching combinations of connections of the image imput/output devices based on an instruction from the control CPU, a dual port for exchanging information between the host CPU and the control CPU through the system bus.

Abstract: A focus detecting device is provided with first and second line sensors and first and second image forming lenses which are located behind a predetermined focal plane of the objective lens to receive the object lights for forming first and second images on the first and second line sensors, respectively. The image signal generated by the first line sensor is divided into a plurality of block signals each consisting of a predetermined number of picture element outputs and each block signal is compared with groups of picture element outputs of the second line sensor, with the groups shifted sequentially, to find a group which best coincides therewith and the distance between the first and second images on the line sensors is calculated in accordance with the shift position of the group thus determined, for calculation of the amount and direction of defocus of the object image on the focal plane.

Abstract: A polarity inverting charger is provided at the location between developing position of a photoconductor and transfer position to invert the polarity of a toner image formed on the photoconductor after a first image is transferred onto an intermediate transfer belt from the photoconductor. A transfer charger is actuated with opposite polarity to that of the polarity when the first toner image is transferred onto the intermediate transfer belt to transfer the first toner image on the intermediate transfer belt onto a second surface of a transfer sheet simultaneously when a polarity inverted second image on the photoconductor is transferred onto a first surface of the transfer sheet.