JPS6084708A - Reflecting mirror for lamp implement - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reflector for common use with illumination lamps, and in particular, the mirror is installed so that its focal point coincides with the light source position and reflects a part of the luminous flux emitted from the light source toward the front. This relates to a reflecting mirror used in

FIG. 1 is a sectional view of an illumination lamp including a conventional reflecting mirror 1 of this type, including the optical axis 2-2. Conventionally, the above-mentioned reflecting mirror 1 is generally configured in the shape of a paraboloid of revolution, and reflects a portion of the light beam emitted from the light source 2 provided at its focal point F in parallel to the optical axis 2-2.

A lens 3 is attached to cover the front opening of the reflecting mirror 1 in order to obtain a desired light distribution pattern by dimming the parallel light beam reflected as described above. FIG. 2 is a partial front view of the lens 3.

In FIG. 1, the light emitted from the light source 2 and reflected by the reflecting mirror 2 is shown by arrows I9-RO and I'9-RO'. Although not shown, in addition to the above-mentioned arrows, there is also light that is emitted directly forward (to the left in the figure) from the light source 2.

As the lens 3, a spherical prism having a large number of concave spherical surfaces or a Kamabobo type prism having a large number of concave cylindrical surfaces is generally used.

Arrows 1 to 1 in FIG. 1 indicate a state in which a beam of light reflected parallel to the optical axis z-2 is scattered by the prism surface 3a.

FIG. 3 shows the light distribution pattern when a screen (not shown) is placed perpendicular to the optical axis 2-2 when using a lens formed with a spherical prism, H-H is the horizontal axis, V- V is the vertical axis.

The luminous intensity distribution on the above-mentioned horizontal axis H-H is shown in FIG. 4. The luminous intensity is maximum at the center and decreases as it approaches the periphery. Although this tendency is common to this type of illumination lamp that has been generally used in the past, it is difficult to control this luminous intensity distribution curve as desired based on the design intention.

FIG. 5 shows a light distribution pattern when using a lens formed with a Kamabot-shaped prism. Even when using a Kamabot type prism, it is difficult to control the light intensity distribution curve as desired.

Conventionally, in order to bring the light distribution of this type of illumination light closer to the desired pattern, various attempts have been made to design the prism provided in the lens 3, but thick prisms or prisms with complicated shapes are expensive to manufacture. Moreover, it is impossible to control the light distribution pattern according to the shape of the prism.

Furthermore, as shown in FIG. 1, conventional illumination lights of this type have a large depth dimension, requiring a large installation volume, and are susceptible to installation restrictions.

In order to eliminate these problems, lens 3 shown in solid line
If the lens is moved back to the position 3' indicated by the imaginary line, a problem arises in that the light emitting area of the lens is reduced.

In view of the above-mentioned circumstances, the present invention was devised to eliminate the drawbacks of conventional devices.The purpose of the present invention is to enable the light distribution characteristics to be arbitrarily set, and furthermore, the lens structure is simple and the light emitting area is reduced. It is an object of the present invention to provide a reflector for a lamp that can be set wide and furthermore allow the depth of the illumination lamp to be configured to be shallow.

In order to achieve the above object, the lamp reflector of the present invention has the following features:
The angle θ with respect to the optical axis of the light incident from the light source toward the reflective surface, the luminous intensity layer 0 of the light source, and the angle a with respect to the optical axis of the reflected light
and [0(XI!+θ=Asin'-(B+Aα) fish α+C
・-Curve-(1) While maintaining the relationship, the coordinates (xl,
zt) and the coordinates (X
2, zz) has a curved surface formed by rotating the continuous curve represented by K around two axes, and the angle θ is set to θ≧0 and the angle α is set to α≧0. Additionally, the angle a is set to increase as the angle θ increases.

FIG. 6 is an explanatory diagram of the angle θ and the angle α shown in the above formula.

Let us consider the light that enters the reflective mirror surface M from the light source position F as shown by arrow W. The point force is an incident point, and 2' indicated by a dashed dotted line is a line passing through the incident point force and parallel to the optical axis 2-2. Arrow y indicates reflected light at the incident point force. In this case, the angle with respect to the optical axis of the light (arrow wa) entering from the light source toward the reflective surface is set to θ, and the angle of the reflected light (arrow y) with respect to the optical axis is set to a.

When the above-mentioned angle θ is further increased by a small angle Δθ, the incident light is reflected from the incident point as shown by the arrow.

f is a line passing through the point of incidence and parallel to the optical axis 2-2.

The imaginary line arrow y' is added for the convenience of explanation, and is an imaginary line drawn parallel to the reflected light arrow y through the incident point, and makes an angle d with respect to the line 2//. are doing.

As mentioned above, when the light incident on the reflective surface M changes from arrow W on the same evening and the angle it makes with the optical axis increases from θ to θ + Δθ, the reflected light arrow Y changes with respect to the optical axis. Compared to the angle α, the angle that the reflected light arrow makes with the optical axis is α+Δa
Therefore, it changes by ΔO. In the reflective mirror of the present invention,
The angle θ and the angle α are expressed as positive in the outward direction and negative in the inward direction with respect to the optical axis 2-2. In the configuration of the present invention, the fact that the angle a increases as the angle θ increases means that the value of Δa remains positive in FIG. In other words, the arrows y and y are not completely parallel, but are slightly in the direction of diffusion.

Generally, the focal point of a concave mirror refers to the point where the incident parallel light beams converge and intersect; however, since the reflecting surface M of the present invention is configured as described above, even if the parallel light beams are incident, it is completely focused. Does not focus on one point.

Therefore, in the reflecting mirror of the present invention, the focal point F refers to the point where the light beams incident parallel to the optical axis direction are converged and have the maximum density.

Next, one embodiment of the present invention will be described with reference to FIGS. 6 to 6. As shown in FIG. 1, let the coordinates of the incident point force at an angle θ be (xl, zl), and the coordinates of the incident point force at an angle θ+Δθ be (xz, zl). The relationship between these coordinates is maintained as shown in equations (2) and (3) above, and a curve M is determined using an analytical mathematical method, and the above curve M is rotated around the optical axis z-2. A reflecting mirror 4 (FIG. 7) is constructed in which all or part of this curved surface is used as a reflecting surface. 5
8 is a lens attached to the front surface of the above-mentioned reflecting mirror 4, and FIG. 8 is a partial front view thereof.

Then, a desired light distribution curve is set as shown in FIG. Figure p shows the light distribution pattern.

In order to obtain the desired light distribution characteristics as shown in these diagrams, the curve M described above is developed as follows.

Points a and b-e shown in FIG. 7 are points of incidence of light emitted from the light source 2, respectively. Arrows indicate reflected light at each of the above incident points.

The angles that the above reflected lights Ra-Re make with respect to the optical axis z-2 are respectively (Ia-Qe).

The above reflection angle aa-ae is plotted on the horizontal axis of FIG. 9, and the maximum luminous intensity 0 at the center and the luminous intensity I end at the periphery are set. The line connecting the center and periphery is 1 = f(
a) = A (represented by 1+B. In this formula, A means the gradient of luminous intensity, and A = Io Iend.

'o 'end B means the minimum luminosity in the periphery, B=LO-A(1
It is ゜.

Ilo in the above equation (1) represents the light source luminous intensity. The open formula (C is c=Il(Iallsθo−Am(X(1+(B+Aα
o) Obtained by cosao. However, θ0 is the angle θ
The initial value of Qo is the reflection angle at that time (that is, the initial value of the reflection angle).

When an illumination lamp is constructed using the reflector 4 constructed as described above, the reflection angle aa increases from the center to the periphery as shown in the reflected light arrow Ra+Rb, ~ light, shown in FIG.
ab, ~06 is thicker. That is, the central portion of the projected light beam is almost a parallel light beam, and the closer it gets to the periphery, the more it tends to diffuse. As a result, the desired luminous intensity distribution illustrated in FIG. 9 is obtained.

In actual practice, the luminous intensity distribution of the reflected light shown in FIG. 9 and the luminous intensity distribution of the light directly projected forward from the light source will overlap. Therefore, when implementing the present invention,
It is desirable to take direct projection light into account when setting the desired reflected light distribution characteristics.

A specific example of a reflective mirror according to the present invention constructed based on the above calculation will be described below with reference to FIG.

FIG.
The coordinate axis perpendicular to Z@, D is the radius of the mirror aperture, and F is the focal point.

The illustrated section V is a portion that does not constitute a reflective surface because it has a hole for inserting the light source pulp.

The coordinates of the focal point F are (0, 0>). When a light source is placed at this focal point F, the minimum value of the angle θ with respect to the optical axis of the light incident on the reflective surface M is 00. The maximum value is θend. θ0 Let the reflection angle (the angle that the reflected light makes with respect to the optical axis) when θend be ao, and the reflection angle when θend be ′end.

Light source luminous intensity 1o = 4 cd, ao force direction target luminous intensity Io
= '7Qcd, target luminous intensity in the 'end direction ■end =
20 cd, opening radius D = 100 wam,
Qo = 0°, Qend = 30°, θo = 40'
and the value of (XO, ZO) is (14,559,-17
, 351). Assuming that the distance f from the light source position to the apex of the reflective surface is 20, the above (sl (2) + (3)
1. Perform calculations based on 2.

In this example, input the above conditions into a computer, and Q
== From Qo to Q=2f)', (x
.

The value of 2) and the value of θ were calculated. The results are shown in the table below.

α θ x z O,00040,00014,559-17,3511
,00040,23314,651-17,3172,
00040,91114,923-17,2203,0
0041,99515,362-17,0654,00
043,43815,959-16,8545,000
45,19216,700-16,5886,0004
7,21117,574-16,2687,00049
,45118,575-15,8928,00051,
87719,696-15,4569,00054,4
5420,934-1,4,95810,00057,
15622, 290-14, 39011, 00059,
95923,767-13,74512,00062,
84425,372-13,01,513,00065
,79627,112-12,18714,00068
,80029,002-11,,24915,0007
1,84731,058-10,18316,0007
4,92633,302-8,96917,00078
,02935,758-7,58218,00081,
15038,461-5,98819,00084,2
8241,452-4,15120,00087,42
044,781-2,01821,00090,557
48,5130,47222,00093,69052
,7303,40023,00096,81257,5
376,87324,00099,91863,070
11,Q2825.000 103.003 69.5
09 16.05226.000 106.061 7
7.095 22.19527.000 109.08
3 86.155 29.80628.000 112
．． 063 97.145 39.37328.230
112.740 000 41.911 As a result of this calculation, a solution that completely satisfies all of the above-mentioned conditions was not obtained, but the maximum value of a was obtained up to 28.230°, which was acceptable. It is judged that the approximate value of =30° is practically satisfactory.

By substituting the respective values for the coordinates of (x, z) based on the above calculation results, a curve M is obtained, and this curve M is connected to the optical axis z-
A curved surface that can be rotated around 2 is obtained.

As an example different from the above, if a reflecting surface that completely satisfies Qend = 30° is required, the value of 6*Iend of the above-mentioned conditions may be slightly decreased and recalculation is performed.

When carrying out the present invention, the reflecting surface may not include the entire curved surface formed as described above, but may include a portion of the curved surface.

In this embodiment, the reflecting mirror 4 (seventh
Since the light reflected by the lens 5 can have almost the desired light distribution pattern, the need for light adjustment by the lens 5 is low. For this reason, the lens 5 of this embodiment is composed of a transparent flat lens. Although it is not prohibited to use a prism lens as a lens used in conjunction with the reflecting mirror of the present invention, even if a prism lens is used, there is no need to use a thick lens or a prism with a complicated shape.

Furthermore, as can be easily understood from FIG. 7, since the reflecting mirror 4 of this embodiment has a shape with a large reflection angle a at the peripheral portion, it is different from the conventional one configured to create a parallel light beam even at the peripheral portion. The concave shape is shallower than that of a parabolic mirror of revolution,
The depth L' of the illumination lamp can be shortened, and the light emitting area of the lens can be set large.

As described above in detail, the reflector for a lamp according to the present invention allows the light distribution characteristics of reflected light to be set as desired, and the lens structure can be simplified to increase the light emitting area. Moreover, it has an excellent practical effect of being able to shorten the depth dimension of the illumination light.

[Brief explanation of drawings]

Figures 1 to 4 show an example of a conventional lighting lamp, with Figure 1 being a cross-sectional view, Figure 2 being a partial front view, and Figure 3 being a light distribution pattern when using a spherical prism. The chart, FIG. 4, is also a chart showing the luminous intensity distribution. Figure 5 shows one of the light distribution patterns when using a Kamabbot-shaped prism in a conventional lighting lamp.
Figure 2 is a chart showing an example. 6 to 7 show one embodiment of the reflector for a lamp according to the present invention, FIG. 6 is an explanatory diagram of curved surface setting, FIG. 7 is a sectional view, FIG. 8 is a partial front view, and FIG. 10 is a chart showing a luminous intensity distribution, FIG. 10 is a chart showing a light distribution pattern, and FIG. 2 is a chart for explaining subtraction. ■... Conventional reflecting mirror, 2... Light source, 3... Lens, 3a... Lens prism surface, 4... Reflecting mirror, 5
···lens. Patent applicant: Ichikoh Industries Co., Ltd. Representative Patent attorney Tadashi Akimoto Figure 1 Figure 3 υ Likelihood Figure 6 Figure 7 Figure 9 Luminosity Figure 11

Claims (1)

[Claims] Installed with the focus almost aligned with the position of the light source of the illumination lamp,
In a lamp reflector for reflecting a part of the luminous flux emitted from the light source toward the front, the angle θ of the light incident from the light source toward the reflecting surface with respect to the optical axis, the luminous intensity NO of the light source, and the reflected light The angle O with respect to the optical axis of
The relationship between the coordinates (X+, Zt) of the point where the light emitted from the light source enters at an angle θ with respect to the optical axis and the coordinates (x*+z*) of the point where the light also enters at an angle θ + Δθ has a curved surface formed by rotating a continuous curve expressed by A reflector for a lamp, characterized in that the angle a is set to increase. However, the above-mentioned A, B, and C are constants that can be selected from a design perspective to determine the light distribution characteristics of reflected light.