Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
METHOD OF MANUFACTURING AN ILLUMINATING REFLECTION MIRROR
BACKGROUND OF THE INVENTION
l.Field of the Invention
The present invention relates to a method of
manufacturing an illuminating reflection mirror that throws
light of a light source upon an object, and more
specifically to a method of manufacturing an illuminating
refection mirror, which determines dimensions of the mirror
by using four or more points for calculating a range of
illumination of the object and light distribution thereof.
2. Description of the Prior Art
Among conventional reflection mirrors installed in
typical illuminating equipment are oval or parabolic
mirrors. They are used for photographing, stage and screen
illumination, lighting for such locations to be seen
particularly at night, and illuminating assembling parts in
a factory and product goods in show rooms.
In a typical conventional reflection mirror, as shown
in FIG. 5, first, a base point r' of a light source R' is
determined with respect to a reflection mirror M' for
scattering the light on a screen S'. Only two points-the
base point r' of the light source R' and a central position
point MS of the reflection mirror M'-are used as data to
determine a light distribution on the screen S'.
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In such conventional reflection mirrors, dimensions of
the mirror are determined based on data of only two points-
the base point r' of the light source R' and the central
position point MS of the reflection mirror M'. This
determination method does not consider to obtain a light
distribution of a desired pattern on a screen.
Further, when the light source projects a cylindrical
ray beam, the associated reflection mirror provides a
circular illumination on a screen.
SUMMARY OF THE INVENTION
Therefore, it is an object of the invention to provide a
method of making an illuminating reflection mirror which can
provide a desired light distribution on a screen or an object
to be illuminated.
Another object of the invention is to provide a method
of making an illuminating reflection mirror which can easily
give a desired shade on an object to be illuminated.
Moreover, in an additional object of the invention, even
if a light source projects a cylindrical ray beam, an
associated reflection mirror can modify it to provide a
rectangular illumination on a screen, in which illumination
intensity is still uniform in its projected area on the
screen.
According to this invention, there is provided a method
of designing an illuminating refection mirror having a
reflective surface, said reflective surface having a shape
corresponding to a desired illumination intensity pattern to
be projected by the mirror on an illumination object, said
method comprising the steps of:
a) providing an illumination object;
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b) defining a plurality of illumination points which
correspond to said desired illumination intensity pattern on
said illumination object wherein a greater density of
illumination points corresponds to a greater illumination
intensity to be applied to said illumination object;
c) locating a light source (R) at a given distance
from said illumination object (S);
d) selecting an initial one of said plurality of
illumination points (Ss) on said illumination object (S) and
a curvature starting point (Ms) on a remote side of said
light source (R) and drawing a first straight line (1La) to
produce an imaginary incident ray from said light source (R)
to said curvature starting point (Ms) and a second straight
line (2La) to produce a reflected ray from said curvature
starting point (Ms) to said initial illumination point (Ss)
to define an angle (Qa) between said first straight line
(1La) and said second straight line (2La);
e) drawing a third straight line (3La) to produce an
incident normal by bisecting said angle (Qa) equally into two
angles;
f) drawing a tangential line (4La) extending through
said curvature starting point (Ms) perpendicularly to said
third straight line (3La) to produce an imaginary reflected
light emitted from said light source (R) that is reflected at
said curvature starting point (Ms) toward said initial
illumination point (Ss) by reflection;
g) selecting an adjacent one of said plurality of
illumination points on said illumination object;
h) locating a first subsequent straight line (1Lb)
from said light source extending at an angle from the
preceding imaginary incident ray and to produce a subsequent
imaginary incident ray and to locate a subsequent curvature
point on said tangential line (4La) while simultaneously
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drawing a second subsequent straight line (2Lb) from said
subsequent illumination point by reflection such that a
subsequent angle (Qb) is defined between said first
subsequent straight line (1Lb) and said second subsequent
straight line (2Lb);
i) drawing a third subsequent straight line (3Lb) to
produce a subsequent incident normal by bisecting said
subsequent angle (Qb) equally into two angles:
j) drawing a subsequent tangential line (4Lb)
extending through said subsequent curvature point
perpendicularly to said third subsequent straight line (3Lb);
k) repeating the steps g) through j) to produce a
series of curvature points which represent a reflective
mirror surface; and
1) designing the mirror with its reflective surface
based on the series of curvature points defined in steps a)
to k) .
According to the present invention, there is also
provided a method of manufacturing an illuminating reflection
mirror from data which is used to produce a curvature of a
reflective surface of said mirror, said reflective surface
having a shape corresponding to a desired illumination
intensity pattern to be projected by said mirror on an
illumination object, from data, said method comprising
determining said data by the steps of:
a) providing an illumination object;
b) defining a plurality of illumination points which
correspond to said desired illumination intensity pattern on
said illumination object wherein a greater density of
illumination points corresponds to a greater illumination
intensity to be applied to said illumination object;
c) locating a light source (R) at a given distance
from said illumination object (S);
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d) selecting an initial one of said plurality of
illumination points (Ss) on said illumination object (S) and
a curvature starting point (Ms) on a remote side of said
light source (R) and drawing a first straight line (1La) to
produce an imaginary incident ray from said light source (R)
to said curvature starting point (Ms) and a second straight
line (2La) to produce a reflected ray from said curvature
starting point (Ms) to said initial illumination point (Ss)
to define an angle (Qa) between said first straight line
(1La) and said second straight line (2La);
e) drawing a third straight line (3La) to produce an
incident normal by bisecting said angle (Qa) equally into two
angles;
f) drawing a tangential line (4La) extending through
said curvature starting point (Ms) perpendicularly to said
third straight line (3La) to produce an imaginary reflected
light emitted from the light source (R) that is reflected at
said curvature starting point (Ms) toward said initial
illumination point (Ss) by reflection;
g) selecting an adjacent one of said plurality of
illumination points on said illumination object;
h) locating a first subsequent straight line (1Lb)
from said light source extending at an angle from the
preceding imaginary incident ray and to produce a subsequent
imaginary incident ray and to locate a subsequent curvature
point on said tangential line (4La) while simultaneously
drawing a second subsequent straight line (2Lb) from said
subsequent illumination point by reflection such that a
subsequent angle (Qb) is defined between said first
subsequent straight line (1Lb) and said second subsequent
straight line (2Lb);
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i) drawing a third subsequent straight line (3Lb) to
produce a subsequent incident normal by bisecting said
subsequent angle (Qb) equally into two angles;
j) drawing a subsequent tangential line (4Lb)
extending through said subsequent curvature point
perpendicularly to said third subsequent straight line (3Lb);
k) repeating the steps g) through j) to produce a
series of curvature points which are used as data to
manufacture a reflective mirror surface; and
1) manufacturing said mirror, the curvature of the
reflective surface of said mirror being determined by the
series of curvature points defined in steps a) to k).
The curvature thus obtained can be used as data for
determining a concave shape of a reflection mirror in a
mirror making process. It is also possible to give a desired
shade on an object to be illuminated. Further, since a
blurred illumination of the object can be eliminated by the
method, products in a show window can be exhibited under a
bright illumination.
Moreover, the light source can be reduced in size,
thus
contributing to an energy saving. In the case of printing
developed pictures, the invention eliminates variations in
their final quality to substantially improve its
productivity.
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BRIEF DESCRIPTION OF THE DRAWINGS
The drawings show embodiments of the invention,
illustrating a method of manufacturing an illuminating
reflection mirror;
FIG. 1 is an explanatory view showing a method of
manufacturing a virtual reflection minor according to this
invention;
FIG. 2 is a partially enlarged view of an essential
portion of FIG. 1;
FIG. 3 is an explanatory view showing a luminous
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intensity distribution according to this invention;
FIG. 4 is an explanatory view showing another luminous
intensity distribution according to this invention;
FIG. 5 is an explanatory view showing a method of
manufacturing a conventional illuminating reflection mirror.
FIG. 6 is the front view of a mirror with an oval
external shape according to this invention; and
FIG. 7 is a sectional side view of the mirror
illustrated in FIG. 6 according to the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
The above object and features of the invention will
become apparent from the following description and attached
drawings.
Referring to FIGS. 1 and 2, a method of manufacturing
an illuminating reflection mirror M according to this
invention firstly sets three point: a base point r of a
light source R; a curvature starting point Ms of a virtual
reflection mirror M at a certain distance from the base
point r; and an illumination starting point Ss of an object
S to be illuminated by a reflected light. This method then
draws a first straight line 1La from the base point r of the
light source R; a second straight line 2La jointing the
curvature starting point and the start point Ss on the
illuminated object S to define an angle Qa in cooperation
with the first straight line lLa; a third straight line 3La
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bisecting the angle Qa; and a fourth straight line 4La that
is perpendicular to the third straight line 3La.
Subsequent illumination points are located on the
object
S at an infinitely small distance away from preceding
illumination points. Each times, a subsequent straight line
(e. g., 1Lb) is located to produce a subsequent imaginary
incident ray extending at an infinitely small angle from the
preceding imaginary incident ray to locate a subsequent
curvature point on the tangential line (e.g., 4La) by
simultaneously drawing a straight line (e.g., 2Lb) from the
sub sequent illustration point by reflection such that a
subsequent angle (e.g., Qb) is defined between the
subsequent straight line (1Lb) and the straight line (2Lb).
A straight line (e.g., 3Lb) is drawn to produce a
subsequent incident normal by dividing the subsequent angle
(Qb) equally into two. Next a subsequent tangential line
(e. g., 4Lb) which extends through the subsequent curvature
point perpendicularly to the straight line (3Lb) is drawn.
These steps are repeated to draw a curvature representing a
mirror surface by use of numerous tangential lines obtained
from the repetition of the steps.
In accordance with a desired luminous intensity
distribution on the screen S', higher density subsequent
illumination points are selected for a greater luminous
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intensity zone . Further, based on thus determined curved
reflection surface of the mirror, an actual luminous
intensity distribution can be easily predicted by use of a
computer.
FIG. 3 shows the luminous intensity distribution
obtained from a method of this invention, in which the light
intensity is high at both ends of the illumined object S and
low at the central portion . FIG. 4 shows another luminous
intensity distribution obtained from this invention, which
shows that the light distribution can be determined so that
the entire object S can be illuminated uniformly.
Moreover, substantially based on the above-mentioned
one dimensional design of a reflection mirror, a two
dimensional curved surface of a reflection mirror can be
determined by applying the same method to another
dimensional direction.
Referring to FIGS. 6 and 7, an oval surface 102 of a mirror
body B is cut out by a bit positioned and controlled by a
computer having a data determined from the above-mentioned
method. Thereby, the shape of the mirror reflection surface
RS is elliptic in X-X' direction. Meanwhile, the reflection
surface RS is also elliptic or parabolic in an perpendicular
direction to X-X' line. This can provide a reflection mirror
modifying a cylindrical incident beam into a rectangular
reflected one.
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