Toshiba Tec Kabushiki Kaisha

Kabushiki Kaisha Toshiba

Other

Toshimitsu Ichiyanagi

Koji Tanimoto

Kenichi Komiya

Jun Sakakibara

Naoaki Ide

Naoyuki Misaka

Koji Kawai

In accordance with an embodiment, an image reading apparatus comprises a sensor configured to read an image in a main scanning direction; a first reference plate; a second reference plate; and a processor configured to determine a parameter for shifting shading correction data on the basis of first reference data obtained through reading on the first reference plate by the sensor and second reference data obtained through reading on the second reference plate by the sensor, set the shading correction data on the basis of data obtained through the reading on the first reference plate by the sensor, acquire image data at each reading position in the sub-scanning direction by the sensor and carry out shading correction on the image data on the basis of the shading correction data shifted according to a shift amount at the each reading position obtained from the parameter.

Image reading apparatus and method providing shading correction

Image reading apparatus providing shading correction with foreign matter detection

A copying machine of the present invention has a scanner including an optical reading unit which optically scans a surface of an original and converts an image on the surface of the original into image data, and a radio communication unit which carries out radio communication with an IC chip having a radio communication function, and a printer including an image forming unit which prints an image on a surface of an image forming medium, and a radio communication unit which carries out radio communication with an IC chip having a radio communication function.

Multi function peripheral having radio reader and writer for communicating with IC chips

A light beam position detecting device detects the passage positions of a plurality of light beams for scanning the surface of a photosensitive drum. The light beam position detecting device has a sensor pattern for generating an output which is continuously changed in a wide range with a variation in the passage position of the light beam in a sub-scanning direction perpendicular to a main scanning direction of the light beam. The sensor pattern precisely detects the relative scanning position of the light beam in a wide range. The passage positions of the plurality of light beams for scanning the surface of the photosensitive drum are controlled to a preset position based on the output of the sensor pattern.

Light beam scanning apparatus

In a digital copying machine using a multi-beam optical system, a sensor pattern senses a light beam directed onto the photosensitive drum and generates current according to the amount of light. The current is converted into a voltage by an operational amplifier acting as a current/voltage conversion amplifier. The output voltage of the operational amplifier is integrated by an integrator. The output of the integrator is converted into a digital signal by an A/D converter, thereby producing luminous energy sensing information. According to the luminous energy sensing information, a laser oscillator is controlled. Between the operational amplifier and integrator, a variable resistor is inserted which absorbs variations in the sensitivity of the sensor pattern or variations in the conversion characteristic of the operational amplifier.

Light beam scanning apparatus and image forming apparatus

The emission level of a laser source at the non-imaging time when image data &ldquo;0&rdquo; is input and the emission level at the imaging time when image data &ldquo;1&rdquo; is input are controlled so that each of them becomes a desired level. The light output intensity is stabilized at all times regardless of variations in ambient temperature. As a result, images uniform in density can be obtained.

Image formation apparatus and method of stabilizing the emission level of semiconductor laser source used therein

A pair of sensor patterns detect a passage position in a sub-scan direction of a light beam scanned over a surface of a photosensitive drum. The sensor patterns have, for example, trapezoidal shapes and are disposed symmetrical at a position equivalent to a position of the surface to be scanned. The sensor patterns are juxtaposed in a scan direction of the light beam at a predetermined interval therebetween. An output integration value from one of the paired photodetector elements successively increases while an output integration value from the other photodetector element successively decreases in relation to a variation of a passage position of the light beam in the sub-scan direction. On the basis of a difference between the output integration values of the paired sensor patterns, the passage position of the light beam in the sub-scan direction is detected.

There is provided an image forming apparatus which can implement digital control of a laser beam scan (analog amount) that moves at high speed, without using any high-speed, multi-bit A/D converter. Upon executing a digital process on the basis of analog detection value Vo corresponding to the passage position or light beam power of a light beam with which a photosensitive drum is irradiated, comparator CMP0, comparison reference value (threshold value) Vr of which changes in correspondence with detection value (integration output) Vo, is used. New comparison reference value Vr is supplied to comparator CMP0 on the basis of digital data BMDA corresponding to output CMPOUT of this comparator.

Growing community of inventors

Zushi, Japan

Toshimitsu Ichiyanagi