Abstract: A zoom lens of the rear focus type comprising, in order from an object side to an image side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power and a fourth lens unit of positive refractive power, wherein the second lens unit and the fourth lens unit are moved to effect zooming and the fourth lens unit is moved to effect focusing, wherein the third lens unit includes a positive first lens and a negative second lens of meniscus form convex toward the image side, and the fourth lens unit includes a negative first lens of meniscus form convex toward the object side and a positive second lens, and wherein an aspheric surface is applied to the third lens unit or the fourth lens unit.

Abstract: In the reproduction of a video signal from tape-shaped recording medium on which plural oblique tracks are formed in parallel manner, the signal processing for interpolating the video signal reproduced by a rotary head is suitably switched according to the transport speed of the tape-shaped recording medium. Thus, satisfactory interpolation can be achieved at different transport speeds, and a reproduced image of satisfactory quality can be obtained.

Abstract: A communication system of this invention is constituted by a controller which accommodates a plurality of extensions connected to an office line and telephones, and includes a facsimile unit for performing facsimile communication with another communication apparatus through the office line, and a plurality of telephones connected to the extensions. The controller can inform an operation state during facsimile communication to the connecting telephone. The operation state of the facsimile unit can be recognized at the telephone. Information received by the facsimile unit can be confirmed at the telephone, and some data received by the facsimile unit can be controlled by the telephone. A registration result of an index number can be commonly used by the telephone and the facsimile unit.

Abstract: This invention provides a sorting method and apparatus, in which identification codes and numeric information to be sorted assigned to these identification codes are entered. When there are a plurality of identification codes having equal numeric information, a first one of these identification codes is written in a first memory at an address corresponding to the numeric information. Next, if there is an identification code from a second identification code onward having numeric information equal to the abovementioned numeric information, this identification code is written in a second memory at an address corresponding to the previously entered identification code. The identification codes thus stored are read out in the order of the addresses of the first memory.

Abstract: A substrate for use with a liquid jet recording head has a semiconductor substrate, functional elements formed on said semiconductor substrate, and electro-thermal transducers electrically connected to the functional elements for generating thermal energy to be utilized to discharge liquid. The substrate comprises a common electrode electrically connected to the functional elements in common. The common electrode has a notch at a position facing control electrodes formed between adjacent functional elements. The notch minimizes the overlap of the common electrode and the control electrodes to decrease the probability of an electrical defect.

Abstract: An optically active lactic acid derivative represented by the following formula (I): ##STR1## wherein R is a saturated or unsaturated hydrocarbon group of a linear, branched or cyclic structure having 4 to 20 carbon atoms; Ra is --CO--Rb or --CH.sub.2 --Rc wherein Rb is a releasable chemically active group, and Rc is a releasable chemically active group; and C with * represents an asymmetric carbon atom.

Abstract: There is disclosed a sheet feeding device having a vibration member for generating vibration for feeding a sheet member. The vibration member is in frictional engagement with the sheet member, which is fed by vibration generated in the vibration member. The device further has a member for controlling the amplitude of the vibration of the vibration member according to the feeding speed of the sheet member whereby the sheet can be fed with a desired speed.

Abstract: A display device has an electron ray generating unit of matrix electrode structure in which a plurality of cold cathodes generating electron rays are arranged two-dimensionally, image storing apparatus for storing therein image information as an amount of charges by a variation in a surface potential produced by the application of the electron rays from the electron ray generating unit, and a display for receiving the application of the electron rays applied from the electron ray generating unit and modulated by the electric charge stored in the image storing apparatus and visualizing the image information.

Abstract: An image forming apparatus includes a first developing device for forming a first toner image and a second developing device for forming a second toner image including a developer carrying member spaced apart from the image bearing member by a distance and a device for applying a developing bias voltage to form an electric field having a maximum voltage Vmax and a minimum voltage Vmin, such that when the first developer is positively charged,.vertline.Vmin-V.sub.T .vertline./d.ltoreq.2.25, or when the first developer is negatively charged,.vertline.Vmax-V.sub.T .vertline./d.ltoreq.2.25,where V.sub.T (V) is a potential of a first toner image immediately before formation of the second toner image after the first latent image is subjected to the charger, the potential of the first toner image being a surface potential of the first toner image under existence of the first latent image.

Abstract: A printing wheel discriminating apparatus comprises a driving device for driving a printing wheel in units of predetermined angles, a detecting device for detecting identification data attached to a specific position of the printing wheel, and a storing device for storing presence/absence data of the identification data corresponding to the specific position of the printing wheel based on the output from the detecting device, thereby discriminating the type of printing wheel.

Abstract: A binocular is provided with a double-cam mechanism between an operation member and an eyepiece portion. The rotation of the operation member is converted by the double-cam mechanism into an axial movement of the eyepiece portion. With this structure, quick and smooth focus adjusting can be carried out.