Japan Science and Technology Agency

Nara Institute of Science and Technology

Funai Electric Company Ltd.

Yuki Maeda

Jun Ohta

Keiichiro Kagawa

Yasuo Masaki

Hideki Tanabe

Yasunari Miyake

Keiichrio Kagawa

Each pixel cell () of an image sensor () is made of a 4-Tr structure, in which only one Tr for resetting a column (X) is so added to an ordinary 3-Tr APS as to reset only an arbitrary pixel selectively, thereby to confine the pixel size. When a pixel signal is to be read, the period, for which the pixel signals composing an ordinary image of one frame are read, is finely divided so that the pixel signals of the pixels receiving an ID light for the period are read out bit by bit and repeatedly. At this time, for only the column being read, an electric current is fed to a read amplifier in the pixel cell () or a variable gain amplifier in an output unit (), thereby to suppress the power consumption. As a result, a lower power consumption and a higher pixel formation can be attained in an image pickup device for picking up an image and for acquiring the ID information of a light beacon existing in the image pickup range.

Imaging device and method for reading signals from such device

In a system for data communication between an information terminal to be operated by a user and remote communication nodes, the present invention intends to suppress the power consumption of the information terminal. For that purpose, communication nodesandeach emit diffuse light carrying a pilot signal blinking at a low frequency to notify the presence of the communication node and an ID signal belonging to a higher frequency range, the ID signal containing inherent address etc. for identifying each communication node. A mobile phoneas the information terminal captures an image and processes the image data to detect the pilot signal of each communication node. Then, determining the position of each node and setting a limited range for reading the pixels around that position, the mobile phonereads the detection signals of the pixels within the limited range at high speed and obtains identification information. This information is used to identify each node and eliminate influences of any other light source that apparently resembles the pilot signal.

Information-processing system using free-space optical communication and free-space optical communication system

For an information terminal to be operated by users for collecting predetermined pieces of information from remote information devices by free-space optical communication, the present invention provides a technique for suppressing the power consumption of the information terminal by minimizing the amount of calculation performed to collect the aforementioned information. According to the present invention, each information device emits ID light on which a low-frequency pilot signal is superimposed. The information terminal captures a series of frames of images including the ID light and locates the ID light within the images by the following steps: (1) creating multiple levels of binned images having different resolutions for each frame of the image; (2) calculating an evaluation index for each pixel within a target range of the binned images at each level, from the lowest to the highest resolution, where the target range is narrowed every time the process switches over to a lower level. In (2), the evaluation index is calculated by an evaluation function including fast Fourier transformation performed throughout the series of frames of images. The evaluation index thus calculated is compared with a threshold to determine whether the pixel concerned is receiving ID light. The present technique significantly reduces the number of pixel to be analyzed and evaluated, thereby decreasing the total number of arithmetic operations to be performed using the evaluation function. Thus, the power consumption is suppressed.

Information-processing device and information-processing system

Growing community of inventors

Ikoma, Japan

Yuki Maeda