Fukuda Co., Ltd.

Fuji Xerox Co., Ltd.

Takaaki Watanabe

Tsutomu Hara

Tomoyuki Yoshii

Chiseki Yamaguchi

Takuya Iwamura

Toshiya Kusayanagi

Naohiko Maruno

Akimitsu Tanabe

Tomoyuki Futami

The present invention provides a method for leak testing by which occurrence of fine leakage from a work as a test object can be determined without being affected by a released tracer gas that is also released from a non-defective work. The method for leak testing includes a series of steps including a gas bombing step wherein a work W as a test object is soaked in a pressurized tracer gas, a work setting step wherein the work subjected to the gas bombing is set in a hermetically sealed container, a vacuum suctioning step wherein the hermetically sealed containeris vacuum suctioned by a suction deviceand a measuring step wherein tracer gas measurement data are obtained by measuring a vacuum suctioned tracer gas with a detector. Tracer gas measurement data for a non-defective work are preliminarily obtained by performing the series of steps for the non-defective work having same specifications as the work W as the test object. The tracer gas measurement data for the work W as the test object are compared with the tracer gas measurement data for the non-defective work in the measuring step, and thereby, occurrence of fine leakage from the work as the test object is determined.

Method for leak testing

In leak testing by an accumulation method, it is possible to reliably detect accumulated inspection gas, and the reliability of leak testing is enhanced by reduction in background or impurity gas. At least an openable/closeable partof a capsuleis housed inside a chamberof a leak testing apparatus. A test workpieceis housed in the capsule. Gas inside the chamberis evacuated by a vacuum pump. A detectordetects inspection gas contained in this gas. The capsuleis continuously sealed for an accumulation time Ta, the capsuleis thereafter opened, and a leak is evaluated on the basis of detection information after the opening by the detector

Leak testing apparatus and method

An intermediate belt made of an endless belt is provided by 45 degrees inclined horizontally and looped over two rollers at both its ends, and four photosensitive drums are provided in contact with the top surface of this intermediate belt. A reflection mirror is provided over each photosensitive drum, and a single polygon mirror is provided on almost the same level as these reflection mirrors. The polygon mirror is provided on the side of the reflection mirror of which optical path to the corresponding photosensitive drum is the longest so that the optical path lengths from the polygon mirror to the respective photosensitive drums are equal to each other.

Color image forming device with simplified optical unit incorporating a laser source

Growing community of inventors

Tokyo, Japan

Takaaki Watanabe