Chuo Hatsujo Kabushiki Kaisha

Hideyo Takeuchi

Taizo Umezaki

Noriyuki Matsumoto

Provided is a shape measurement device that measures a shape of a spiral spring formed in a spiral shape. The shape measurement device is provided with an input means and a function calculation means. The input means inputs a captured photographic image depicting the spiral spring or measurement data produced by measuring the shape of the spiral spring. The function calculation means uses the input photographic image or measurement data to calculate at least an inter-coil space function representing the space between neighboring coils of the spiral spring, a pitch function representing the distance between coil cores of neighboring coils of the spiral spring, or a coil thickness function representing the thickness of coils of the spiral spring.

Device, method, and program for measuring shape of spiral spring

The present invention provides technologies for narrowing down fingerprints images, which will be used for identity determination, without extracting auxiliary information such as a fingerprint pattern, thereby shortening the time required for fingerprint verification. The device according to the present invention includes a storage meansfor storing characteristic information extracted from fingerprint images of registered persons, and a collection meansfor collecting a fingerprint image. First, a extraction meansextracts characteristic information from the fingerprint image collected by the collection means. Next, a narrowing meanscalculates a similarity between part of the characteristic information of the person to be identified, which was extracted by the extraction means, and corresponding part of the characteristic information of each of the registered persons, which is stored in the storage means. Based upon the calculated similarity, the registered fingerprints that will be used for the identity determination are narrowed down. Then, an determination meansdetermines whether or not the characteristic information of each of the registered fingerprints, which were narrowed down by the narrowing means, matches the characteristic information of the person to be identified, which was extracted by the extraction means According to this device, the registered fingerprints that will be used for the identity determination are narrowed down by using the characteristic information that will be used for the identity determination. Therefore, without extracting auxiliary information, such as a fingerprint pattern, from the collected fingerprint image, the fingerprint images that will be used in order to determine the identity of the fingerprint are narrowed down. Thus, the time required for the fingerprint verification can be shortened.

Fingerprint verification device and fingerprint verification method

The present invention determines whether fingerprint ridgeline information is contained within the fingerprint image using a simple method by considering the properties of the fingerprint ridgeline. In this fingerprint image evaluation method, a density is obtained of a reference point provided within the fingerprint image and a density is obtained of a comparison point that is shifted from the reference point by a predetermined distance. The amount of fingerprint ridgeline information contained within the fingerprint image is evaluated based upon a difference between the density of the reference point and the density of the comparison point. In this fingerprint image evaluation method, the characteristic of the fingerprint ridgeline, in which a fingerprint furrow line exists proximally to the fingerprint ridgeline, is utilized. Therefore, erroneous determinations can be prevented in which an image, which is not in fact a fingerprint image, is determined to be a fingerprint image. In addition, it is only required to obtain the density of the reference point and the density of the comparison point, and to calculated their difference. Therefore, time consuming processing is not necessary, such as is required to extract characteristic points from a fingerprint image.

Growing community of inventors

Nagoya, Japan

Hideyo Takeuchi