Illumination – Illuminated scale or dial – Edge illuminated modifier or light rod/pipe
Reexamination Certificate
1999-09-14
2002-01-15
Husar, Stephen (Department: 2875)
Illumination
Illuminated scale or dial
Edge illuminated modifier or light rod/pipe
C362S023000, C362S029000, C362S030000, C362S084000, C116S048000, C116S288000
Reexamination Certificate
active
06338561
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a luminous pointer applicable to various kinds of measuring instruments and the like. More particularly, the invention is concerned with an improvement of a luminous pointer which introduces light for illumination from a central part of its swing motion and glows in the form of a line.
BACKGROUND ART
A luminous pointer of this kind known in the prior art is constructed such that illuminating light is introduced from an external light source into a pointer element formed of a transparent material, causing it to glow in the form of a line.
More specifically, there is provided a reflecting part in a central region of swing motion of the pointer element formed of a transparent resin material, such as an acrylic resin or polycarbonate, for reflecting the illuminating light toward an extreme end of the pointer element and the central region of swing motion of the pointer element including the reflecting part is covered with a light-blocking cover in which a slit for exposing a glowing surf ace area is formed. In this construction, a glowing surface which illuminates in a continuous line-shaped pattern including the central region of swing motion covered with the light-blocking cover is obtained when the illuminating light introduced into the pointer element is delivered toward its extreme end by way of the reflecting part.
In this type of luminous pointer wherein the central region of swing motion covered with the light-blocking cover serves as part of the glowing surface and the aforementioned reflecting part is provided immediately beneath the pointer element as described above, a portion of the glowing surface located within the central region of swing motion which serves also as an illuminating light inlet area glows with relatively higher intensity. Under this circumstance, there have been proposed some arrangements to achieve uniform illumination of the glowing surface. One known arrangement is to form a cavity in the central region of swing motion and mount a filter element which alters the amount of transmission of the illuminating light within the cavity as disclosed in Japanese Utility Model Laid-Open No. 12995/1994, for example. Another arrangement is to dispose a light-blocking plate (shielding element) having a hole corresponding to the reflecting part in the back of the central region of swing motion to restrict the illuminating light introduced as disclosed in Japanese Utility Laid-Open No. 90324/1993.
Luminous pointers whose central region of swing motion serves as part of a glowing surface include such a type that has a reflecting part located to the side of the glowing surface of the pointer element as disclosed in Japanese Utility Laid-Open No. 124596/1989. In this type of luminous pointer, however, an area located in the central region of swing motion serving as the illuminating light inlet area tends to become relatively brighter as well. Thus, still another known arrangement is constructed such that the central region of swing motion of the pointer element including an area corresponding to the reflecting part is covered with a light-blocking element of the same type as the light-blocking plate disclosed in Japanese Utility Laid-Open No. 90324/1993 and a hole corresponding to the reflecting part is formed in the light-blocking element. This arrangement is intended to restrict an inlet path of the illuminating light in the central region of swing motion to an area corresponding to the hole to thereby to achieve uniform illumination.
The aforementioned arrangement in which the filter element is mounted as a means for achieving uniform illumination of the glowing surface, however, has a problem that a shadow of the filter element is created in an area of the glowing surface corresponding to the filter element because the location of the filter element is relatively close to the glowing surface, and this can impair the commercial value.
The arrangement in which the illuminating light to be introduced is restricted by use of the light-blocking plate has such a problem that an area of the glowing surface which is located in the central region of swing motion and covered by the light-blocking plate, for instance, could become dim and it is difficult to achieve uniform illumination of the glowing surface, because the inlet path of the illuminating light is restricted to the area corresponding to the reflecting part exposed through the hole due to the existence of the light-blocking plate. The lack of brightness of this kind in an area of the glowing surface located in the central region of swing motion is likely to occur especially in the arrangement in which the reflecting part located to the side of the glowing surface.
This invention has been made in the light of the foregoing problems. Accordingly, it is an object of the invention to provide a luminous pointer which can offer an increased commercial value by causing its glowing surface to glow generally uniformly.
DISCLOSURE OF THE INVENTION
A luminous pointer according to the invention is constructed of a pointer element which is made of a light-transmitting material and forms an indicating portion (glowing surface), a light-blocking cover which covers a central region of swing motion of the pointer element and opens rearward, and a shielding element which covers the rear side of the central region of swing motion of the pointer element. The pointer element has in its central region of swing motion reflecting parts for reflecting illuminating light fed from the rear side at least toward its tip end, and the shielding element is formed of a light-transmitting material and has an exposing part for exposing the reflecting parts of the pointer element. Since the illuminating light which has passed through the shielding element is introduced into the central region of swing motion of the pointer element in addition to the illuminating light that is introduced directly through the exposing part, the amount of entire illuminating light introduced into an area of the glowing surface located within the central region of swing motion is increased, making it possible to suppress unevenness in brightness of the glowing surface.
In other words, besides that portion of the illuminating light which is introduced directly through the exposing part made in the shielding element, and not passing through it, into the area of the glowing surface located within the central region of swing motion, another portion of the illuminating light of which amount has been adjusted by passing through the shielding element is also supplied. As a result, the amount of light delivered to that part of the glowing surface which is located within the central region of swing motion and covered by the shielding element is increased and this makes it possible to cause the glowing surface to glow generally uniformly.
REFERENCES:
patent: 5911492 (1999-06-01), Perry et al.
patent: 5983827 (1999-11-01), Cookingham et al.
patent: 6082288 (2000-07-01), Kato et al.
patent: 6161934 (2000-12-01), Griffin et al.
patent: 0 610 105 (1994-08-01), None
patent: 2 687 470 (1993-08-01), None
patent: 2 721 396 (1995-12-01), None
patent: 1-124596 (1989-08-01), None
patent: 2-26019 (1990-07-01), None
patent: 5-90324 (1993-12-01), None
patent: 6-12995 (1994-02-01), None
patent: 8-10777 (1996-03-01), None
patent: 9-96550 (1997-04-01), None
patent: 9-96551 (1997-04-01), None
patent: 09/096550 (1997-04-01), None
Husar Stephen
McDermott & Will & Emery
Nippon Seiki Co. Ltd.
Ton Anabel
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