Asahi Kogaku Kogyo Kabushiki Kaisha

Makoto Nukui

Shuzo Seo

Nobuhiro Tani

Takeharu Shin

Yukihiro Ishizuka

Mitsunori Iima

Tadashi Minakuchi

A stationary data symbol reader includes a CCD, lens, CCD drive circuit, amplification circuit, binarization circuit, memory, CPU, light sources, light source drive circuit, communication driver, switch circuit and trigger switch. When reading, a frame image capture is carried out, and a number of picture elements of the fields of the frame corresponding to the displacement of an authenticator pattern (associated with the data symbol) between a second field image and a first field image is calculated. The moving speed of the data symbol is calculated from the displacement. The optimal light exposure time is calculated from the moving speed, and the optimal intensity of illumination is calculated from the exposure time.

Data symbol reading system

A light intensity control apparatus includes an optical beam splitter which splits light into monitor light and principal light; a polarization beam splitter which splits the monitor light into two polarized light components; a monitor light detector which detects the polarized light components; a polarization correction device which corrects the output of the monitor light detector so that the intensity of the output signal of the monitor light detector and the light intensity of the principal light on an object surface have a predetermined correlation, regardless of the polarization state of the light incident upon the optical beam splitter; and a humidity dependency correction device which corrects the output of the monitor light detector via the polarization correction device by detecting a variation in polarization dependency characteristics of the optical beam splitter, caused by a change in humidity, and feeding the variation back to the polarization correction device, so that the output signal intensity of the monitor light detector and the light intensity of the principal light on the object surface have a predetermined correlation, regardless of a change in the humidity. The invention is also directed to a light intensity control method.

Apparatus and method for controlling light intensity

In a laser scan based recording apparatus, laser light from a measuring laser diode is directed to one reflecting surface of a polygonal mirror. The reflected light is detected with a measuring photodiode. The reflectance of laser light is calculated from the detection output of the measuring photodiode and a reference voltage is generated. When the reflecting surface has rotated to the position where the laser light from laser light source scans a photoreceptor drum, the emission output of the laser light source is controlled by a laser output control circuit on the basis of the generated reference voltage. Despite variation in reflectance among the multiple reflecting surfaces of the polygonal mirror, the photoreceptor is scanned with a constant optical intensity of laser light. Since automatic power control is performed at all times, overdriving of the laser diode is effectively prevented to protect it against breakdown, producing consistent and highly reliable laser power control.

Laser scan based recording apparatus

A data symbol reading device has a casing which includes a hand grip and a head part. The casing includes signal processing circuits, a light source, an image sensing device, and an optical system. The optical system directs light reflected from a symbol reading area such that an image is formed on a light receiving surface of the image sensing device. An indication unit, comprised of five LEDs, is provided on an easily visible surface of the casing. If, in the reading process, it is determined that a data symbol is fully within the symbol reading area, a central LED is illuminated. However, if the data symbol is protruding outside the symbol reading area, one or more LEDs are illuminated to indicate the direction of protrusion.

Data symbol reader and method including data symbol position evaluation

A data symbol reading device is provided with a white light source, a single-color LED light source, and mode selection switches. The reading device is controlled to have a symbol reading mode, a color image scanning mode, and a monochrome image scanning mode based on the position of the selection switches. The reading device transmits data as appropriate to a host computer. Alternatively, the symbol reading device is provided with red, green, and blue single-color light sources, and has the same modes. Further, the symbol reading device may be provided with a three or four color filter wheel and a white light source to generate the color and monochrome images.

Data symbol reading device

A casing of a data symbol reader has a grip portion and head portion. A signal processing circuit is housed in the grip portion. A light source for illumination, an image sensing device, and an optical system for imaging the symbol reading area on the light receiving surface of the image sensing device are housed in the head portion. A housing extends from the head portion towards a symbol reading area, and the symbol reading area is formed as a front opening of the housing. A trigger switch for initiating the reading operation and a trigger button for actuating the trigger switch are positioned at the side of casing. The trigger switch and trigger button are supported by a supporting structure in a manner enabling movement with respect to casing.

Data symbol reader including adjustable trigger switch unit

A casing, including a grip portion and a head portion, houses a pair of light sources for illumination, an image sensing device, an optical system for forming an image on the image sensing device, a photosensor for detecting the luminance of symbol reading area, a signal processing circuit, and a light quantity detection circuit. The housing extends from the head portion towards the symbol reading area. An ambient light window is provided in the housing for introducing ambient light into the symbol reading area. A light source driving circuit controls an amount of light emitted by the light source, by increasing or decreasing the amount of light, such that the combined ambient light and light source illumination is between predetermined levels. A selector is provided for selecting between a first mode, in which a maximum illumination is decreased to an upper limit of an acceptable illumination range, and a second mode, in which a minimum illumination is increased to a lower limit of an acceptable illumination range.

Data symbol reader utilizing ambient light illumination

A data symbol reader for reading a one-dimensional data symbol and a two-dimensional data symbol includes first and second image pickup devices, both having a light receiving surface to receive light reflected from the one-dimensional and two-dimensional data symbols. An optical system respectively converges images of the one-dimensional and two-dimensional data symbols onto the light receiving surfaces of the first and second image pickup devices. A signal processing device is provided for decoding the one-dimensional and the two-dimensional data symbols from outputs of the first and second image pickup devices.

One-dimensional and two-dimensional data symbol reader

An optical reader having a reading head which includes a light source, an optical system and in imaging device such as a CCD. An opening is formed in a tip portion of the reading head which forms an area in which an information pattern to be read is positioned. The information pattern is illuminated by the light source, and the light reflected from the information pattern is sensed by the CCD. A closing plate is slidably supported by guide grooves provided on edge portions of the opening. The opening is opened and closed by the closing plate. The closing plate has a plurality of notches to provide flexibility.

Optical reader for information pattern representing coded data

A data symbol reading device for decoding a data symbol is provided with a reading head which has an opening for contacting a symbol reading surface on which the data symbol is positioned. The reading head also includes an optical system for forming an image of the data symbol on an imaging device. The imaging device outputs the image to a processing device which determines that the data symbol is read properly. The data symbol reading device further includes a printing device for printing a predetermined code on the data symbol in response to the processing device determining that the data has been properly read. The data reading device further includes a print mode selection system which selects one of a plurality of printing modes. The printing device prints none or at least one of the predetermined codes in response to the printing mode selected by the print mode selection system.

Growing community of inventors

Tokyo, Japan

Makoto Nukui