JPH0140088Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an illumination lamp having a rectangular illumination light emitting surface and used as a headlamp for an automobile.

[Prior Art] Round headlamps have been the mainstream for automotive headlamps, but rectangular headlamps have recently come into widespread use. To put it simply, a square shape is a round shape whose top, bottom, left and right sides are cut out with flat surfaces so that it looks like a square when viewed from the front.

A headlamp consists of three parts: a light emitting part (bulb), a parabolic reflector, and a front lens. When the rectangular lamp is removed, the light emitted from the cut out parts A, B, C, and D cannot be used, resulting in a dark lamp.

In order to prevent this reduction in light intensity, square headlamps generally use a mirror 4 that is slightly larger than the conventional round reflector 3, as shown in Fig. 11, and take out a rectangular headlamp with an inscribed square 5. In this way, the loss of light in the vertical direction is compensated for by light in the diagonally shaded areas in the left and right directions (light that did not need to be used with the round shape).

In addition, we use halogen bulbs that are brighter (30 to 40% more light) with the same power consumption to prevent this reduction in light intensity.

By the way, as shown in Figure 12a, square headlamps have an aspect ratio of about 1:1.4 to 1:2, but recently, due to design requirements and to reduce air resistance of cars and improve fuel efficiency. There is a demand for further thinning.

However, if the bulb is formed by cutting the top, bottom, left and right sides of a round shape with flat surfaces, the thinner the bulb is, the more the amount of light emitted from the bulb will escape in the vertical direction, as shown in Figure 12b and c. The ratio increases, and in the case of light bulbs with the same power consumption, a reduction in light intensity is inevitable. Furthermore, improvements in the efficiency of halogen light bulbs have almost reached their limits, and making them thinner has become a difficult problem.

Some luxury car models have a system in which the headlights are folded down and stored under the bonnet when not in use, such as during the day, and the headlights are raised when driving at night. Increased air resistance is unavoidable. Also, a method of forming a set of headlamps by arranging a plurality of small rectangular headlamps has been considered, but there are problems in terms of maintenance and the like.

[Purpose of the invention] The purpose of the invention is to provide a thin and bright lighting fixture.

[Summary of the invention] The invention involves arranging a light bulb so that the filament is located at the focal point of a paraboloid of revolution reflector whose front aperture is square, and changing the light emitted downward from the filament to the side. A lower direction-changing reflector that unfolds in a fan shape is placed below the light bulb, and an upper direction-changing reflector that reflects the light of a certain radiation angle including directly above the light emitted upwards forward. An auxiliary reflector is disposed above each of the light bulbs, and is further connected to the lower edge of the paraboloid of revolution reflector for projecting the light from the lower direction changing reflector onto a horizontally elongated square front lens as a substantially parallel beam. It is characterized by being provided as follows.

[Example] Figures 1 to 6 show an example of the present invention, in which 11 indicates a main filament M and a sub-filament S.
A light bulb with a shade SD and a shade SD, for example a light bulb called H4, 12 is a paraboloid of revolution reflector, and its shape when viewed from the front is horizontally elongated. Reference numeral 13 denotes a horizontally long front lens whose vertical dimension is larger than that of the reflecting mirror 12. 14 is the paraboloid of revolution reflecting mirror 12
The auxiliary reflecting mirror is connected to the lower edge of the lens 13 and has a strip-shaped plate curved so that its plane draws a parabola. It is about the size. Reference numeral 15 denotes a lower direction changing reflector for fanning out the lower luminous flux of the main filament M of the light bulb 11 to the left and right and projecting it onto the auxiliary reflector 14, which has an apex below the main filament M; The reflecting surface is a substantially triangular block curved to form a parabola (for example, focal length F = 4.5 mm), and its height h is the same as the width of the strip of the auxiliary reflecting mirror 14. . In addition, the reflecting mirror 15 and the main filament M
The positional relationship is such that the axis passing through the focal point of the parabola (referred to as the focal axis) and the filament center axis substantially coincide.

Reference numeral 16 denotes an upper direction changing reflector placed above the sub-filament S of the light bulb 11, which directs the direct light from the sub-filament S and the reflected light from the shade SD toward the main reflecting surface. 1
6A is curved to form a parabola (for example, focal distance F=4.5 mm), and the front side is expanded at an angle of ±25°. The focal axis of this upper direction changing reflector 16 is located near the rear end of the sub-filament S, and is perpendicular to the filament center axis. Further, a concave spherical reflecting surface 16B with a diameter of about 24 mm is formed behind the main reflecting surface 16A and directly above both filaments M and S. This reflective surface 16
The center of B is the main filament M and the secondary filament S
Near the middle of , the same height as the bottom of the shade SD
It is set at position 0, which is a little lower than that.
Furthermore, the upper direction changing reflector 16 has side plates 1 on both sides.
It has 6C and 16C'. This side plate 16C,1
6C' refers to the front left and right sides of an automobile headlamp.
Since there is no need to illuminate an area exceeding about 30°,
The light that spreads at a large angle left and right is used as light in the front direction, and the use of light may be increased by forming a quadratic curved surface.

If the structure is as above, the main filament M
The light emitted further downward is reflected by the reflecting mirror 15 and spreads as if it were emitted from the filament M' (FIG. 5). In that case, this luminous flux does not spread in the vertical direction, but has a fan-shaped light distribution. An auxiliary reflector 14 is placed near the key point of this fan.
The reflected light from the reflecting mirror 15 becomes a substantially parallel light flux that is regulated both vertically and horizontally, and is radiated forward.

Note that the light emitted upward from the filament M is passed through the paraboloid of revolution reflector 12 in the same manner as before, except for a part.
It is reflected and radiated forward. A part of the light gathers on the inner surface of the shade SD, and a percentage of it is reflected by the main reflection surface 16A of the upper direction changing reflector 16 and is projected forward.

On the other hand, when the auxiliary light is turned on (see Figure 6), one end of the filament S is on the focal axis, so this filament end is located on the H line of the screen (assumed for convenience of explanation) 20, and below it filament statues will be lined up.

In addition, the reflected light from the shade SD spreads out as if the light source were located at the positions of the filament images S', S'', S... At this time, too, if one end of these filament images is located near the focal axis. Therefore, as described above, a filament image is formed on the screen 20 with the H line as the upper end.

These light fluxes become a uniform light band as a whole and illuminate the area below the H line. Tests yielded an average of 700 cd.

When the above-mentioned auxiliary light is turned on, the light emitted directly above the filament S forms a real image several mm below the main filament M due to the presence of the reflective surface 16B. Reflector 1
4, the light beam is projected onto the screen 20 in the same manner as in the case of the downward beam described above. Since this real image is located below the main filament M, that is, below the focal axis of the lower direction changing reflector 15, the light band on the screen 20 is below the H line and contributes to the sublamp light distribution.

Among the reflected light from the shade SD, the light that enters the spherical reflective surface 16 also contributes to the sublamp light distribution. That is, since the center of curvature 0 of the reflective surface 16 is located at a height slightly below the shade SD, the light that enters the reflective surface 16B passes directly below the main filament S (forms an image), and as described above, By the function of the lower direction changing reflector 15 and the auxiliary reflector 14,
Screen 20 so that the light band is located below the H line
projected onto the top.

Incidentally, the main reflecting surface 16A of the upper direction changing reflector 16 is located at a portion quite far away from the focal point (for example, F=4.5 mm and 11 mm ahead of the focal point). It is the main reflecting surface 16 as shown in FIG.
When A is extended to the vicinity of the focal point as shown by the dotted line, the downward spread angle α due to the curved surface directly above the filament S (dotted line part) and the downward spread angle β (< α ), and a considerable difference (several times) in the width of the light band on the screen 20, resulting in an excessive amount of downward luminous flux, making the road in front of the car too bright, and causing This is because it tends to become difficult to drive.

FIGS. 8a and 8b and 9a and 9b are comparison examples of the light distribution pattern of the present invention and the conventional one. However, it is shown without a lens cut.

In the present invention, as shown in Figure 8a, the main light distribution is approximately the same as the conventional one (Figure 8b) above the H line, but below the H line, the horizontal width is ±10°, and the vertical width is In addition to the 4° light band, spot light is also generated by the downward beam, and a total of 80,000 to 100,000 cd of spot light is created in the center. As a result, the light distribution pattern and light amount are sufficient for the main light distribution of the headlamp, and by adding a lens cut, a thin lighting fixture having the desired main light distribution of the headlamp can be easily realized.

As shown in FIG. 9a, the secondary light distribution is controlled by the main reflection surface 16A of the upper direction change reflection line 16.
A uniform light band of about 600 to 1000 cd is now formed below the line over a wide range of about ±30°, and a bright butterfly-shaped pattern is formed, just like before (Figure 9b). In combination with this, the absolute light quantity shortage is resolved. As a result, the bright portion can be used mainly for distant (middle and far) illumination, and a sub-lamp light distribution that is bright even with a thin design and has little upward light can be obtained.

In the above embodiment, the reflective surface 16B of the upper direction changing reflective line 16 is a concave spherical surface, but it may also be a quadratic curved surface such as an ellipsoid or a paraboloid. Furthermore, the focus and center position of each reflecting mirror can be selected within a fairly wide range. For example, in the lower direction changing reflector 15, F
= 2 to 10, and for the auxiliary reflecting mirror 14, a value of F = 20 to 40 mm can be adopted. Furthermore, the light bulbs used are
It is not limited to _H4 bulbs; for example, it is also possible to use _H4 bulbs with no shades but with the filament shifted, or C-6/C-6 types with filaments arranged side by side. be.

Although the above description is for the case where the lamp is used as an automobile headlamp, it is applicable not only to headlamps but also to lighting in general.

[Effects] As described above, according to the present invention, there is a reflector for changing the lower direction of the filament, which turns the downward light flux of the filament sideways and expands it into a fan shape, and a lower side of the paraboloid of revolution reflector whose front opening is square. An auxiliary reflector is provided that is connected to the end and radiates the light from the reflector forward as a substantially parallel beam of light, and forms a horizontally elongated light distribution pattern by two reflections, while also directing the light radiated upward from the filament. Since an upper direction-changing reflector is provided to reflect the light forward and a light band with a required width is formed beyond the H line, a thin and bright lighting fixture can be obtained.

[Brief explanation of the drawing]

1, 2, and 4 are cross-sectional views showing one embodiment of the lighting fixture according to the present invention, FIG. 3 is a front view of the same embodiment, and FIGS. 5 and 6 are the same embodiments. FIG. 7 is a diagram for explaining the downward spread angle of the reflected light from the main reflecting surface of the upper direction changing reflector in the same embodiment, FIGS. 8 a, b, and 9 a ，
b is a light distribution pattern diagram, Figures 10 and 11 are diagrams to explain the difference in light intensity between a round headlamp and a square headlamp, and Figures 12a, b, and c are requirements for thinner square headlamps. It is a perspective view showing degree. 11... Light bulb, 12... Rotating paraboloid reflector, 1
3...Front lens, 14...Auxiliary reflector, 15...
...Reflector for lower direction change, 16...Reflector for upper direction change, M...Main filament, S...Sub-filament, SD...Shade.

Claims (1)

[Claims for Utility Model Registration] (1) A light bulb is arranged so that the filament is located at the focal point of a paraboloid of revolution reflector whose front opening is square, while the light emitted downward from the filament is directed sideways. a lower direction-changing reflector that changes direction and unfolds in a fan shape below the light bulb; an upper direction-changing reflector that reflects light in a certain radiation angle range including directly above the light emitted upward; are arranged above the light bulbs, and furthermore, an auxiliary reflector is arranged at the lower edge of the paraboloid of revolution reflector for projecting the light from the lower direction changing reflector onto a horizontally elongated square front lens as a substantially parallel beam of light. A lighting fixture characterized by being provided in a connected manner. (2) The reflecting surface of the lower direction-changing reflector and the main reflecting surface of the upper direction-changing reflector are parabolic curved surfaces, and the focal axis of the main reflecting surface and the center of the filament are parallel to the lamp optical axis. The illumination lamp according to claim 1, which is a utility model registered and is arranged in such a manner that the axis thereof is orthogonal to each other. (3) The illumination lamp according to claim 2, wherein one end of the filament is located near the focal axis of the main reflecting surface of the upper direction changing reflector.