JP3207031B2 - Reflector for vehicle lighting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention obtains a light distribution pattern diffused in the horizontal direction without depending on the light distribution control function of a lens step, and gradually changes the light distribution pattern from the center to the periphery. It is an object of the present invention to provide a novel reflector for a vehicular lamp capable of realizing the following luminous intensity distribution.

[0002]

2. Description of the Related Art As streamlining of a vehicle body is required in response to aerodynamic characteristics and design requirements relating to styling of a vehicle, the front portion of the vehicle body is formed into a narrowed shape. It is necessary to design a headlight corresponding to slant nose, and a reflector that can use a transparent lens that does not form lens steps as much as possible or a lens that is almost transparent in the front lens disposed in front of the reflector Is desired.

As an example of such a reflecting mirror, as shown in US Pat. No. 1,898,167, a parabola having a different focal length is set between a horizontal plane including the optical axis of the reflecting mirror and a vertical plane. It is known that a reflecting surface is formed by moving a parabola in a vertical plane with a short focal length as it is in a horizontal direction along a parabola in a horizontal plane with a long focal length.

[0004] The applicant of the present application has disclosed Japanese Patent Publication No. 59-536.
No. 41 discloses a reflecting mirror having a shape that easily obtains wide diffusion in the horizontal direction. The reflecting surface of the reflecting mirror is obtained by adding a higher-order term to a parabolic equation with a reference curve in a horizontal section including a reference axis. Expression (y ² = 4 · f · x + a · x ⁿ , where f is a =
The focal length of the reference parabola when n = 0, a and n are constants, and a> 0 and n> 1. ), And is formed as an envelope surface of a group of rotating paraboloids that touch the point on the reference curve and share the focus with the reference parabola.

[0005]

However, the above-mentioned reflecting mirror has the following problems regarding the luminous intensity distribution in the light distribution pattern.

That is, in the light distribution pattern of an automotive lamp, it is fundamental to obtain a pattern which is largely diffused in the horizontal direction as compared with the vertical direction, such as a cornering lamp, a front turn signal lamp, a stop lamp and the like. In such a case, a light distribution pattern is required in which the luminous intensity is gradually attenuated from the center to the peripheral portion, and the luminous intensity distribution gradually decreases from the center to the periphery, but the former (U.S. Pat. Is adopted as the basic curve, the luminous intensity distribution of the light distribution pattern obtained by these becomes large in the relative luminous intensity difference between the central part and the peripheral part, and it is formed on the front lens to compensate for insufficient diffusion. The dependence of the lens step performed on the light distribution control increases.

The latter (Japanese Patent Publication No. 59-53641)
In the reflector, the shape of the light distribution pattern obtained when a point light source is placed at the focal point is substantially rhombic, and the portion toward the peripheral portion in the horizontal direction is tapered. The relative luminous intensity difference between the peripheral portion and the peripheral portion in the horizontal direction is conspicuous.

[0008]

SUMMARY OF THE INVENTION Therefore, in order to solve the above-mentioned problems, a reflector for a vehicle lamp according to the present invention has a reflector for a vehicle lamp capable of forming a light distribution pattern diffused in a horizontal direction. In the mirror, a reference curve set on a horizontal plane including a reference axis and a reference curve set on a vertical plane including the reference axis are defined as in the following equation.

X = (h ² / r) / (1 + √ (1- (1+
K) · (h / r) ² )) + ΔM (h ⁿ ) where “x”
Coordinates set on the reference axis, "h" coordinates set on an axis orthogonal to the x-axis in a horizontal plane or vertical plane including the x-axis, "r", "K" is a constant, ".DELTA.M (h ⁿ⁾ Is a correction term, which is an n-th (n is an even number equal to or greater than 4) polynomial of a positive coefficient related to h.

Then, a reflecting surface is formed by translating one reference curve along the other reference curve so that its reference axis is located in a horizontal or vertical plane including the reference axis of the other reference curve. .

[0011]

According to the present invention, the quadratic curve is modified by setting the order of the correction term added to the quadratic curve equation with respect to the reference curve in the horizontal plane and the vertical plane, and the reference axes are parallel to each other. By forming the reflecting surface as a group of curves obtained by moving one of the reference curves along the other curve, the light distribution pattern is horizontally adjusted so that no extreme difference in luminous intensity occurs between the central portion and the peripheral portion. The luminous intensity distribution along the direction and the vertical direction can be controlled independently.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a reflector of a vehicular lamp according to the present invention.

FIGS. 1 to 3 show the formation of a reflecting surface of a reflecting mirror according to the present invention.

FIG. 1 shows a reference curve 1 set on a horizontal section including a reference axis. An orthogonal coordinate system having a reference axis as an x-axis and an axis in a horizontal plane orthogonal to the reference axis as a y-axis is set. Have been.

Reference curve 1 is expressed by the following equation obtained by adding a polynomial correction term to the quadratic curve equation.

[0016]

(Equation 1)

In the above equation, "r" is a paraxial radius of curvature, "K" is a conic constant, and A _n (n is an even number of 4 or more) is n.
This is a positive coefficient according to the following term.

[Equation 1] can be reduced to a quadratic curve expression if the fourth or higher order term of y is ignored. For example, if K = −1, then a parabola with a focal length r / 2 is represented. If K> -1, an ellipse is represented.

FIG. 1 also shows a dashed parabola 2 in comparison with the reference curve 1. As is clear from the fact that the coefficient An of the correction term is a positive value, the reference curve 1 has a parabola 2 The shape is closer to the x-axis side.

Curves 3 and 4 shown in FIG. 1 show the effect of the correction term on the quadratic curve. Curve 3 shows the quadratic curve equation obtained by adding only the fourth-order correction term. 4 is 2
The equation of the following curve is obtained by adding only the sixth-order correction term.

Among the correction terms, the correction term having a small order n affects the shape of the paraxial portion near the x-axis of the reference curve 1, and the correction term having the large order n among the correction terms is x Affects the shape of the part away from the axis.

Similarly, the reference curve set on the vertical section including the reference axis is represented by an equation obtained by adding a polynomial correction term to the quadratic curve equation.

That is, when an orthogonal coordinate system is set in which the reference axis is the x-axis and the axis in the vertical plane orthogonal to the x-axis is set, the reference curve is expressed by the following equation.

[0024]

(Equation 2)

In the above equation, "r" is a paraxial radius of curvature, "K" is a conic constant, and _Bn (n is an even number of 4 or more) is n.
This is a positive coefficient according to the following term.

As shown in FIG. 2, the reflecting surface is formed by changing the reference curve 5 set in a vertical section including the reference axis to the reference curve 1 described above.
Is formed by translating in the horizontal direction.

That is, the reference curve 5 is set such that the vertex P of the reference curve 5 is always positioned on the reference curve 1 and the reference axis of the reference curve 5 is parallel to the reference axis of the reference curve 1. The reflecting surface 6 is formed as a curved surface formed by an operation of moving the reflecting surface 6 in the horizontal direction.

It should be noted that which of the reference curve 1 and the reference curve 5 is moved relative to the other is a relative matter.
As shown in FIG. 3, the reference curve 1 is set such that the vertex Q of the reference curve 1 is always positioned on the reference curve 5 and the reference axis of the reference curve 1 is parallel to the reference axis of the reference curve 5. It may be made to move in the vertical direction along the reference curve 5.

The upper left diagram in FIG.
When a point light source is placed at the focal position according to the following curve term, the pattern 7 projected on the screen in front by the reflection surface 6
"HH" in the figure indicates a horizontal line,
“VV” indicates a vertical line.

The projection pattern 7 has a horizontally-long, substantially rectangular shape, and its luminous intensity distribution is such that the central portion is bright and the brightness gradually decreases toward the peripheral portion. By providing a difference in the order of the correction term between the luminous intensity distribution in the horizontal direction and the luminous intensity distribution in the vertical direction, the degree of decrease in luminous intensity can be varied.

That is, the correction terms in the reference curves 1 and 5 are as follows:
The higher-order term has a shape effect of deforming the shape of the peripheral portion of the reference curve to the reference axis side from the quadratic curve. Therefore, optically, the reflected light at the peripheral portion of the reference curve intersects with the reference axis. This light can be used as light that contributes to the formation of the central luminous intensity portion in the projection pattern.

For example, in the equation [Equation 1] showing the reference curve 1, the correction term is A ₄ · y ⁴ + A ₈ · y ^8, and in the equation [Equation 2] showing the reference curve 5, the correction term is B ₄ · z ⁴ +
If B ₆ · z ⁶ , the rate of decrease in luminous intensity from the center to the periphery of the projection pattern is relatively greater in the horizontal direction than in the vertical direction.

FIG. 4 schematically shows a luminous intensity distribution diagram located on the right and below the projection pattern 7 in FIG. The diagram below the projection pattern 7 is a horizontal luminous intensity distribution diagram, and the diagram on the right side of the projection pattern 7 is a vertical luminous intensity distribution diagram. In both figures, the “L” axis indicates the luminous intensity.

As described above, in order to reduce the luminous intensity relatively gradually from the center to the periphery, a low-order term is used as a correction term, and the contrast between the center and the periphery is relatively low. In order to realize the obtained distribution, a higher-order term may be used as a correction term. Note that the distinction between high order and low order is determined based on the luminous intensity distribution, and is not uniformly defined based on a specific order.

FIGS. 5 to 7 show an example of a vehicular lamp using the reflecting mirror according to the present invention, and show an example in which the present invention is applied to a reflecting portion of a front turn signal lamp.

The vehicular lamp 8 has a lamp body 9 having an open front, a front lens 10 arranged so as to cover the front opening of the lamp body 9, and a light emitting portion at a predetermined position in the lamp body 9. Light bulb 11.

In the lamp body 9, a reflection surface is formed by performing a reflection process on an inner surface of a portion near the rear end, and this portion is used as a reflection portion 12.
Instead of forming the reflecting surface on the inner surface of the lamp body 9 as described above, a configuration in which a separate reflecting mirror is provided in the lamp body 9 may be adopted.

Reference numeral 13 denotes a rear end wall protruding rearward from the rear end surface of the lamp body 9, and the light bulb 11 is provided on the rear end wall.
Is attached.

The bulb 11 has the glass bulb 15 as the reflecting section 1.
2 is disposed at a predetermined position in the lamp body 9 through the circular hole 12a formed in the lamp body 2, and a flange portion 16a provided on the base 16 and engaging portions 16b, 16b provided on the front side of the flange portion 16a. .. Are detachably supported by the mounting member 14.

Numeral 17 denotes a coil-shaped filament, which is arranged so that its central axis extends in the horizontal direction.

Reference numerals 18 and 19 denote side walls of the lamp body 9. The left side wall 18 extends forward from the front end of the reflector 12, and the right side wall 19 extends rightward and rearward from the front end of the reflector 12. It is formed so as to extend further and be folded back. The outer end portions of the side walls 18 and 19 are provided with a lens mounting portion 2 for mounting the front lens 10.
0 is formed.

The lens portion 21 of the front lens 10 is curved so as to follow the curved shape of the front nose (shown by a two-dot chain line in FIGS. 5 and 6) of the vehicle body, and the lens portion 21 has a lens step. It is a lens that is transparent or almost transparent. A peripheral wall 22 projecting rearward is formed integrally with the lens part 21 on the outer peripheral edge of the lens part 21, and a mounting ridge 23 is provided rearward on an end edge of the peripheral wall 22 on the side opposite to the lens part 21. It is projected toward. The front lens 10 is attached to the lamp body 9 by screws or the like in a state in which the mounting ridge 23 is received in the groove 20a of the lens installation portion 20 of the lamp body 9.

Reference numeral 24 denotes an inner cap for covering the glass bulb portion 15 of the light bulb 11, and is provided to constitute a colored light source together with the light bulb 11.

FIG. 7 shows the front shape of the reflecting section 12.

The reflection surface of the reflection section 12 is divided into four reflection areas 25, 26, 27, and 28 with respect to the light distribution control.

The reflection areas 25 and 26 occupy most of the reflection surface, and both are designed by the same method as the reflection surface 6 described above.

When viewed from the front, the reflection area 25 is located on the left side of a vertical plane including the main optical axis of the reflection section 12 (the axis extending perpendicularly to the plane of the drawing through the center of the circular hole 12a in FIG. 7). The reflection area 26 is located on the right side of the vertical plane including the main optical axis of the reflection section 12.

As shown in FIG. 8, the reference axes of the reflection areas 25 and 26 are inclined with respect to the main optical axis of the reflection section 12.

In the drawing, "LL" indicates the main optical axis of the reflecting section 12, and the reference axis of the reflection area 25 indicated by "L25-L25" is the axis LL in the horizontal plane including the LL axis. Are inclined at a predetermined angle with respect to.

Similarly, for the reflection area 26, "L26-
The reference axis indicated by "L26" is inclined at a predetermined angle with respect to the axis LL in a horizontal plane including the LL axis.

By inclining the reference axes of the reflection areas 25 and 26 with respect to the LL axis in this way, it is possible to prevent the central luminous intensity portion in the light distribution pattern from becoming unnecessarily bright.

As shown in FIG. 7, the remaining reflection areas 27 and 28 are located at the upper left corner and the lower left corner of the reflection area 25, respectively, and each of them has a spheroidal shape.

FIG. 9 shows a substantially cross-shaped light distribution pattern 29 obtained by the vehicular lamp 8, in which the luminous intensity distribution is schematically represented by equal candela lines.

The reflection regions 25 and 26 mainly contribute to the formation of a horizontally long rectangular portion which is a basic pattern of the light distribution pattern 29, and the shortage of the light amount above and below the reflection regions 27 and 28 compensates.

[0055]

As is apparent from the above description, according to the present invention, the reference curve set on the horizontal plane including the reference axis and the reference curve set on the vertical plane including the reference axis are quadratic curves. And a correction term (even-order polynomial) is added to one of the reference curves along the other reference curve such that its reference axis is located in a horizontal or vertical plane including the reference axis of the other reference curve. The reflection surface is formed by parallel movement, and the luminous intensity distribution along the horizontal direction and the vertical direction can be independently controlled by deforming the quadratic curve by setting the order of the correction term and the like, The light distribution control can be performed without the help of the lens step of the front lens so that an extreme difference in luminous intensity does not occur between the central portion and the peripheral portion of the light distribution pattern.

It should be noted that the specific shapes and structures shown in the above embodiments are merely examples for embodying the present invention, and the technical scope of the present invention is limitedly interpreted. It is not something to be done. For example,
In the above-described embodiment, the central axis of the filament of the bulb is arranged in the horizontal direction orthogonal to the main optical axis of the reflecting portion, but the central axis of the filament is along the main optical axis of the reflecting portion. Is also good.

[Brief description of the drawings]

FIGS. 1A and 1B show an example of a reference curve in a horizontal plane with respect to a reflecting surface of a reflecting mirror according to the present invention, wherein FIG. 1A is a diagram showing an outline of a curved shape, and FIG. It is a figure which expands and shows.

FIG. 2 is a perspective view for describing a reflection surface formed by translating a reference curve in a vertical plane along a reference curve in a horizontal plane.

FIG. 3 is a perspective view for explaining a reflection surface formed by translating a reference curve in a horizontal plane along a reference curve in a vertical plane.

FIG. 4 is a diagram schematically showing a projection pattern by a reflector according to the present invention and a luminous intensity distribution in horizontal and vertical directions.

5 shows an example of a vehicular lamp using the reflecting mirror according to the present invention, together with FIGS. 6 to 9, and is a horizontal sectional view. FIG.

FIG. 6 is a longitudinal sectional view.

FIG. 7 is a front view of a reflecting mirror.

FIG. 8 is a schematic diagram illustrating a relationship between a reference axis of a reflection area constituting a reflection surface and a main optical axis of the reflection surface.

FIG. 9 is a diagram schematically showing a light distribution pattern by a reflecting mirror.

[Explanation of symbols]

 1 Reference curve set in horizontal plane 5 Reference curve set in vertical plane 6 Reflection surface x Reference axis 25, 26 Reflection area L25-L25, L26-L26 Reference axis LL Main optical axis of reflector

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F21S 8/10 F21W 101: 14

Claims (2)

(57) [Claims] 1. A reflector for a vehicular lamp capable of forming a light distribution pattern diffused in a horizontal direction, comprising: (1) a reference curve set on a horizontal plane including a reference axis and a vertical surface including the reference axis; The reference curve to be set is represented by the following equation: x = (h ² / r) / (1 + √ (1- (1 + K) · (h /
r) ² )) + ΔM (h ⁿ ) (where “x” is a coordinate set on a reference axis, “h” is a coordinate set on an axis orthogonal to the x axis in a horizontal plane including the x axis or a vertical plane, "R",
“K” is a constant, “ΔM (h ⁿ )” is a correction term, and is a polynomial of degree n (n is an even number of 4 or more) of a positive coefficient related to h. (2) A reflective surface is formed by translating one reference curve along another reference curve such that its reference axis is located in a horizontal or vertical plane that includes the reference axis of the other reference curve. A reflector for a vehicular lamp. 2. A vehicular lamp using the reflecting surface of the reflecting mirror according to claim 1, wherein the reflecting surface is divided into two reflecting regions by a vertical plane including a main optical axis of the reflecting mirror. A reflecting mirror for a vehicular lamp, wherein a reference axis of each reflecting area is inclined with respect to a main optical axis of the reflecting mirror.