[in Japanese]

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A CCD linear sensor employing a high-speed driving dot sequential color method is developed for color image scanners. This device has only one row of sensors in dot sequential form and a separate register for each primary color. The output signals are therefore unaffected by the positional deviation of the sensors and the color mixing due to transfer degradation. The data rate of this device is 18 MHz, twice that of a conventional linear sensor employing the same configuration of sensors and registers. This improved data rate is due to the difference in potential between conventional and the present CCD registers and faster clock timing.

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Two flip-chip semiconductor bonding methods and two types of optical plates have been developed. In addition, two types of multi-chip direct contact-type bipolar IC image sensors have been developed for graphic image scanners used in office equipment such as facsimiles, intelligent photo copy equipment and computers. This is the first time that the above bonding methods and optical plates have been used in this kind of application. These image sensors achieve compact size, light weight and high reading performance (MTF-value 65%, Focus-depth 0.3 mm).

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An MCCS (Multi-Chip Contact Sensor) shows high performance, with a low noise level below 15 mv and a high output frequency of 2 MHz/bit. Such high performance was achieved by using a clamping circuit to reduce the difference of offset voltage among individual chips, an FPN (Fixed Pattern Noise) cancelation circuit and high drivability OP-AMP.

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This paper describes a 100-MHz datarate, 5000 element CCD linear image sensor with 20.3μ V/electron amplifier sensitivity. A reset-pulse level-adjustment circuit with a reset gate potential detector, and a self-aligned technique to minimize floating diffusion node capacitance are used to achieve this performance. The reading speed is triple and the photo-sensitivity is twice that of conventional linear image sensors with more than 5000 elements.
This sensor is able to scan an 11-inch sheet in 50 μs with 400-dot-per-inch resolution.

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A highly-sensitive linear color sensor was developed with 5000-pixels × 3 lines. A simple voltage amplifier is installed in its output circuit. The amplifier consists of an AC coupling capacitor, a negative feedback capacitor and a clamp MOS transistor, in addition to an MOS inverter amplifier. Like a built-in CDS circuit, this amplifier reduces noise to as low as around 20 e^-/pixel (rms) without using an outer circuit. It also achieves stable operation without delicate voltage adjustment, and stable voltage characteristics with sensitivity of 74μ V/e^- for the blue channel and 53μ V/e^- for red and green channels.

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[in Japanese]

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[in Japanese]

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This paper describes an image retrieval method that uses an abstract matching and browsing technique. Each image in database is divided into segments and each segment is represented by its color, shape, and position (each represented image is called a segment image). The user creates a key image consisting of colored rectangular areas. This key image and the segment images in the database are compared and segment images are selected according to their similartity with the key image. Similarity is measured based on color, position, size, and geographical relation of each area. The user selects the desired image by browsing through the seleced segment images. It is experimentally shown that a desired image can be retrieved easily by using the proposed method.

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A new motion detection scheme that extracts one-frame differences in PAL signals is described. A high-precision motion-adaptive luminance-chrominance (YC) separation and motion-adaptive field rate up-conversion using this motion information are also described.
It is determined that a conventional field rate up-conversion scheme causes two harmful effects : ghost images and jagged motion images. These images can be reduced by using a motion-adaptive filter in the field rate up-conversion.
The developed enhanced-PAL decoder provides high-quality pictures without cross-component degradation or large-area flicker.

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A three-dimensional optometer III (TDO III) is used to measure subjects' visual rerponses while gazing at a varying-radius spotlight in an otherwise completely dark room. Three emmetropic females serve as subjects and the stimuli are presented at 33 cm (-3D) from the subjects. It is determined that the subjects feel as if the spotlight approaches them when the radius is increased. However, the magnitude of the accommodation towards a smaller radius spotlight is greater than that towards a larger radius spotlight. This means that the eye accommodates farther, even though the spotlight is felt to approach the subjects subjectively, contradicting common scientific knowledge based on the subjectively measured data reported by W. H. Ittleson and A. Ames in 1950. Supplemental experiments indicate that this phenomenon is due to the effort to dynamically reduce accommodation lag so that the smaller target can be seen more clearly.

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