Abstract: A method for measuring indentation resistance includes: obtaining a first curve indicating a yield shear stress in a depth direction of a raceway surface of a material forming a rolling bearing in a state before the raceway surface is subjected to machining, a second curve indicating a static shear stress in the depth direction of the raceway surface in a state in which the raceway surface is subjected to the machining, and a third curve indicating a static shear stress in the depth direction of the raceway surface in a state in which rolling elements are in contact with the raceway surface and a static load is applied to the raceway surface; and obtaining a correlation between an area and an indentation depth of the raceway ring by defining a region surrounded by exceeding the first curve and the second curve and falling below the third curve as the area.

Abstract: An image forming apparatus includes: a plurality of light-emitting elements, each light-emitting element receiving a driving current from a power supply and converting the current into a beam; a plurality of driving elements, each driving element being interposed between the power supply and each light-emitting element and controlling the driving current based on an image signal; and a photoconductor on which the beams from the plurality of light-emitting elements form an image by scanning, wherein each light-emitting element is positioned so immediately adjacent to each driving element that a power leakage factor floating therebetween is reduced, whereby an intensity of the beam is substantially equivalent to the image signal in waveform.

Abstract: A color image forming device that can certainly correct uniform velocity error associated with the characteristic of each optical system and can realize high-quality color image printing by performing a fine laser beam irradiating position control, in consideration of an error in surface accuracy of each mirror surface of a rotary polygon mirror. The color image forming device includes a storage unit for holding uniform velocity correction data previously created for each mirror surface of a rotary polygon mirror to correct a distortion in expansion or contraction of the electrostatic latent image in the main scanning direction due to the characteristic of an optical system, and an image clock generating unit for reading uniform velocity correction data on each mirror surface used in the rotary polygon mirror at a scanning time out of the storage unit and then generating image clock pulses for image signal creation with a period corresponding to the uniform velocity correction data.

Abstract: A light scanning controller includes a plurality of light scanning parts for forming a latent image on a photoconductor by irradiating it with a scanning laser beam, and a clock controller for generating a timing signal by using a single clock signal obtained from a master clock oscillator to transmit the timing signal to each of the light scanning parts which controls the timing of the scanning laser beam on the basis of the timing signal received from the clock controller.