Abstract: The present invention provides an ink jet printer which performs recording by causing a nozzle to discharge an ink drop onto a recording medium. The nozzle is connected to an ink channel in which aqueous ink is housed. The printer head can vary the dot size on the recording medium by changing the size of the drop that is discharged from the nozzle. The aqueous ink has a degree of surface tension change .DELTA.S that is expressed by the relation .DELTA.S=(S.sub.1 -S.sub.3)/ S.sub.2 of 0.3 or less, wherein S.sub.2 is the surface tension at 25.degree. C., and has a value of 20 to 50 dynes/cm, S.sub.1 is the surface tension at 5.degree. C., and S.sub.3 is the surface tension at 40.degree. C.

Abstract: In an electrophotographic copying machine, image quality is improved by suppressing phenomena such as narrowing and thickening of a linear image or discharge noises in a photograph image due to anomalies on transfer of a toner image. For example, a document type is discriminated and when a transfer brush is used for transfer, transfer current and pretransfer erasing are controlled according to the type of document image. The pretransfer erasing is controlled in various following situations: Bi-level exposure method or multi-level exposure method, edge emphasis, photoelectric efficiency, the surface potential of the photoconductor, and position of a developing device.

Abstract: An internal state determining apparatus according to the present invention includes at least one inner circuit, means for detecting a change in voltage supplied from an external device and outputting a detected signal in response to the change in voltage and internal state determining means for determining the inner circuit so as to fall into a predetermined state in response to the detected signal, as components that make up the internal state determining apparatus. Owing to the internal state determining apparatus having such a construction, when an IC card is activated in response to two types of different voltages, for example, an internal state of the IC card can be determined.

Abstract: In a semiconductor memory, a plurality of semiconductor memory modules are connected through a common clock signal line and one or more other signal lines to an accessing circuit. The accessing circuit has a timing information storage unit for storing predetermined access timing information associated with the respective semiconductor memory modules, and a timing varying unit for varying a data receiving timing at a transfer destination in compliance with a semiconductor memory module to be accessed, on the basis of the access timing information stored in the timing information storage unit.

Abstract: In a digital image forming apparatus, a user can select a desired gradation curve representing the relation of the density of reproduced image to the input image signal obtained by reading a document among a plurality of gradation data stored in a memory in correspondence to image forming conditions of an electrophotographic process of forming an image. The image forming condition is determined separately. A gradation correction data is calculated from the gradation data to realize the object gradation curve. Then, an input image signal is converted to light quantity data for a beam for exposing a photoconductor by using the calculated gradation correction data to form a latent image on a photoconductor in the image forming conditions.

Abstract: An image forming apparatus having an image editing function and a plurality of developing devices capable of developing different colors respectively, wherein, for example, where images are copied from two sheets of document or a double-side document on the both sides of a copying paper, or where the both pages of an opened book are copied in a split manner, the position on a copying paper of change-over of the developing device is set only for one sheet of document in double-size copy from the respective two sheets of document, only for one page of the opened book, and only for one side of the double-side document, and thereby the position of change-over is determined automatically for the other sheet of document, the other page or the rear side, and therefore the devices for setting the position of change-over of the developing device are reduced in number, and the operation is simplified.