Stock material or miscellaneous articles – Structurally defined web or sheet – Including variation in thickness
Reexamination Certificate
2003-10-09
2004-11-16
Loney, Donald J. (Department: 1772)
Stock material or miscellaneous articles
Structurally defined web or sheet
Including variation in thickness
C063S032000
Reexamination Certificate
active
06818280
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a rectangular brilliant-cut of a diamond provided with a new facet configuration. The rectangular brilliant-cut is sometimes referred to as the princess cut.
2. Description of the Related Art
The size of an ornamental cut diamond depends on the size of the raw stone. In particular, the crown height, pavilion depth and girdle size are determined by the size of the raw stone.
Even if the size of a diamond is the same, the brilliancy of the diamond is varied by its cut. The present inventors have introduced, for a round brilliant cut diamond, the concept of “visual-perceptible reflection rays,” and on the basis thereof have invented a cut design which can increase the visual-perceptible reflection ray amount for the purpose of evaluating the brilliancy that can be perceived by an observer when a diamond is observed; and the patent application thereof has been made (Japanese Patent Application No. 2002-253011 filed Aug. 30, 2002 and its counterpart foreign Patent Applications, e.g., for the US, U.S. Ser. No. 10/350,388, filed Jan. 23, 2003).
In the previous patent application of the round brilliant cut diamond, the amount of physical reflection rays was obtained in such a manner that meshes are defined by dividing the radius of the diamond into 100 equal segments and the ray density was obtained with respect to each mesh. Since the radius of diamonds is several millimeters, a mesh area is several hundred square micrometers. The amount of light was calculated only with respect to patterns of 30 meshes or larger by considering the area perceptible by human eyes. Amounts of visual-perceptible reflection rays were defined to be the square root of values of tenths of the amount of physical reflection rays with respect to all the patterns, and the sum of the amounts of visual-perceptible reflection rays was obtained with respect to all the patterns. That is, the amount of visual-perceptible reflection rays was calculated by the following equation:
The amount of visual-perceptible reflection rays=&Sgr;{(the amount of physical reflection rays with respect to patterns of 30 meshes or larger in each segment)/10}
1/2
, in which &Sgr; is the sum of patterns in one segment.
When a diamond is observed by an observer above the table of the diamond, the light rays incident from the backside of the observer are blocked by the observer and hence do not reach the diamond. On the contrary, the light rays with large incident angles do not effectively contribute to the reflection. Accordingly, by assuming that the light rays with the incident angles of 20 to 45 degrees with respect to the normal to the table facet of the diamond (namely, the center line connecting the table facet center and the culet) are effective light rays, the intensity of the reflection derived from the above described range of incident light rays is referred to as “the effective visual-perceptible reflection ray amount,” and a cut design capable of increasing the effective visual-perceptible reflection ray amount has also been investigated in the above described patent application.
In the study of the reflection rays from the diamond, the above described effective visual-perceptible reflection ray amount is effective when uniform light rays are incident from around all the surrounding portions; on the other hand, when the light is irradiated from a plane ceiling, it is necessary that the light intensity is represented by cos
2
&thgr; where &thgr; is the incident angle.
In the rectangular brilliant-cut, there are formed a rectangular columnar girdle between a rectangular upper cross section and a rectangular lower cross section parallel thereto, a crown above the girdle, and a pavilion below the girdle. Because a rectangular brilliant-cut with a square girdle is often used, description will be made below assuming that a square cross section is provided.
As
FIG. 16
shows the top view,
FIG. 17
shows the side view and
FIG. 18
shows the bottom view, the conventional rectangular brilliant-cut
400
has a square truncated pyramid shape crown
420
above a rectangular columnar girdle
410
having a square cross section and a square pyramid shape pavilion
440
below the girdle
410
. In these figures, the respective x, y and z axes are shown on the basis of a coordinate system having its origin at the center of a horizontal cross section bb′bb′ formed with four vertexes in the underpart of the girdle
410
. The center line connecting the table facet center and the culet R is taken as the z axis, and the horizontal cross section bb′bb′ is taken as the xy plane. The square truncated pyramid shape crown
420
has on the surface thereof the table facet
421
, four bezel facets
423
, four crown girdle facets
427
, four second bezel facets
429
, and eight star facets
431
. The table facet
421
is situated on a plane parallel to the xy plane. The table facet
421
is the top plane of the truncated pyramid shape crown
420
; in which four first vertexes F,F′ are respectively provided near the upper vertexes B, B′ of the square girdle
410
, and four second vertexes Del each is located at a point displaced outwardly from the midpoint of a line segment, connecting two neighboring first vertexes F, F′ of the four first vertexes, along the line connecting the table center and the midpoint; thus, the table facet
421
is an octagon formed by connecting each of the four second vertexes Del with the adjacent pair of the four first vertexes F, F′ respectively in one-to-one correspondence with the four vertexes B, B′ of the girdle. A bezel facet
423
is a quadrilateral BCFD in which a pair of diagonal vertexes are the pair of a vertex B and a vertex F or the pair of a vertex B′ and a vertex F′ where the vertexes B and B′ are the upper vertexes of the girdle
410
and the vertexes F and F′ are respectively in one-to-one correspondence with the vertexes B and B′. Each crown girdle facet
427
is a trapezoid BB′CC′ which is formed with a side (for example, BB′) of the upper cross section of the girdle
410
and the sides BC and B′C′, closest to the above described girdle edge BB′, among the sides in the two bezel facets
423
each having as a vertex thereof any of the two ends B and B′ of the side BB′. A second bezel facet
429
is a triangle CC′Del which is formed with the side CC′, parallel to and opposite to the girdle edge BB′ among the sides of the crown girdle facet
427
, and a second vertex Del, opposite to the midpoint of the side BB′ of the girdle facet
427
, among the vertexes of the table facet
421
. A star facet
431
is a triangle CFDel which is enclosed with a side FDel of the table facet
421
, a side CF of a bezel facet
423
and a side CDel of the second bezel facet
429
.
A square pyramid shape pavilion
440
has on the external surface thereof four pavilion main facets
441
, four pavilion girdle facets
443
, and a plurality of facets
447
,
449
and
451
dividing a portion between a pavilion main facet
441
and the pavilion girdle facet
443
. Each of the pavilion main facets
441
is a quadrilateral bLRL′ in which a vertex b in the lower portion of the girdle and the lower apex (culet) R of the square pyramid shape pavilion
440
are a pair of diagonal vertexes. The straight line passing through the lower apex R of the square pyramid shape pavilion
440
and the table facet center will be referred to as the “center line” (the z axis), and the plane including the center line and dividing an edge of the square girdle at the midpoint thereof will be referred to as the “center dividing plane” (the zx or yz plane). Every pavilion facet
441
has the vertexes L and L′, opposing each other, on the center dividing planes, and a pair of adjacent pavilion facets share the side LR connecting the vertex L on the center dividing plane intervening the pair of facets and
Itoh Akira
Kawabuchi Yoshinori
Matsumura Tamotsu
Hohoemi Brains, Inc.
Loney Donald J.
McGlew and Tuttle , P.C.
LandOfFree
Rectangular brilliant-cut diamond does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rectangular brilliant-cut diamond, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rectangular brilliant-cut diamond will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3296033