Hitachi, Ltd.

Eiichi Hara

Tatsuya Nagata

Michihiro Watanabe

Takehiko Yamada

Seiichi Hayashi

Shigetoshi Hiratsuka

Kazuyoshi Mego

A digital signal is provided by correcting image signal distortions contained in an image signal outputted from an elongated direct contact type image sensor in an image reader such as a facsimile device, which image sensor reads patterns on a document in contact with the document. The image signal distortions of the sensor output are so-called shading distortions due to sensitivity distribution of sensor elements or distribution of light from light sources onto the document. Signal distortions are corrected from both a white signal outputted from the sensor when a white document is read and a black signal outputted when a black document is read. The white signal and the black signal are stored and reproduced to generate a reference signal which is obtained by dividing the voltage range across both the signals at a predetermined ratio. The digital signal is obtained by comparing the sensor output with the reference signal. If necessary, a pseudo-black signal may be produced by dividing the voltage of the white signal.

Method and apparatus for correcting an image signal

A photoelectric transfer element of which a reading sensor for reading written materials such as facsimile documents has a controlled photosensitive region within the photoelectric transfer element. Thus photosensitivity in a region of the photoelectric transfer element is reduced to improve element performance. The specific photosensitivity control methods include an electric field control, increased impurity concentration, and irradiation ultraviolet light.

Line image sensor with controlled photosensitivity

In a contact-type image sensor for use in a facsimile equipment or the like, the surface of the sensor is provided with a transparent film which is electroconductive and of which the surface that is in contact with the sensor elements is formed as a roughened surface capable of scattering light. By virtue of the provision of this film, static electricity generated during the running of the original is prevented from causing fluctuations in the sensor output voltage. In addition, light reflected by the surface of the transparent film is prevented from becoming directly incident on the sensor elements and, hence, from causing abnormal increases in the sensor output.

Facsimile equipment with direct-contact-type image sensor

Direct-contact-type image sensor and image sensor assembly

The lead wires extending from heating resistors to a driver IC for the heating resistors are arranged in the space under the driver IC. These lead wires are constructed in that they become narrower in wire width as approaching the driver IC so as to lie within the width of the driver IC, and the lead wires positioned under the driver IC are constructed in that they become broader in wire width as approaching the connecting terminals of the driver IC. Connection of the lead wires and the driver IC is carried out by the face-down bonding using Controlled Collapse Bonding. By providing the construction as mentioned above, a thermal print head of higher density and definition can be obtained.

Thermal print head

In a contact type photoelectric converter device suited for use in facsimile transmitters and character readers, a light transmitting section for transmitting light emitted from a light source is juxtaposed in the vicinity of a row of photoconductive film so that the surface of an original is uniformly illuminated and a major portion of reflected light rays from the original impinges on the photoconductive films thereby improving an efficiency of light utilization.

Growing community of inventors

Chigasaki, Japan

Eiichi Hara