JPH0138805Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a vehicle lamp in which an inner lens is provided inside an outer lens on the front surface of the housing so that the light emitted from the bulb becomes a ray parallel to the optical axis of the lamp. It is.

[Prior art]

A conventional example of this type of vehicle lamp is shown in FIG.
In FIG. 7, 1 is a housing, 2 is a bulb (light bulb), 3 is an outer lens, and 4 is an inner lens. The outer lens 3 has a central area R that serves as a reflex reflector, and this area serves as a non-light emitting surface. Further, the inner lens 4 is located inside the outer lens 3, and its Fresnel cut focuses the light emitted from the bulb 2 in the direction of the optical axis of the lamp. This light is appropriately diffused by a fisheye cut on the outer lens 3.

However, in such a structure, even though the size of the inner lens 4 is S, since the range R is a reflex reflector, the light emitted from the bulb 2 that enters this range becomes ineffective. Therefore, the light emitted from the bulb 2 is not effectively utilized, and the luminous intensity of the lamp is reduced.

[Purpose of invention]

An object of the present invention is to provide a vehicle lamp that can effectively utilize the light emitted from the bulb even if there is a light shielding part such as a reflex reflector on a part of the front surface of the lamp.

[Summary of the idea]

The present invention provides a vehicle lamp in which an outer lens having a part of the light shielding part is placed on the front of the housing, and an inner lens is provided inside the outer lens to condense the light emitted from the bulb in the direction of the optical axis of the lamp. A primary refraction cut whose shape is determined by a predetermined calculation formula is made by using two inner lenses each having a prism cut for optical axis control made of a total reflection prism cut, and the prism cut surfaces are arranged approximately parallel to each other so that they face each other. The lamp is arranged so that the emitted light directed from the bulb towards the light shielding part is refracted outside the light shielding part and then directed in the direction of the optical axis of the lamp.

〔Example〕

1 to 3 show an embodiment of the present invention, in which 11 is a housing, 12 is a bulb, 13 is an outer lens disposed on the front surface of the housing 11, and the range R in the center is a reflex lens. It has become a Tsukusu reflector. 14 is a first inner lens, 15 is a second inner lens, the first inner lens 14 is located inside the outer lens 13, and the second inner lens 15 is located inside it, that is, closer to the bulb 12. It is placed.

A Fresnel cut is applied to the entire rear surface (bulb 12 side) of the second inner lens 15, and an optical axis control prism cut (a primary refraction cut and a total reflection prism cut (secondary refraction cut) 1 is provided on the front surface.
5B) is applied to the entire surface. Primary refraction cut 1
5A focuses the light emitted from the bulb in the direction of the optical axis of the lamp by one refraction, and the total reflection prism cut (secondary refraction cut) 15B refracts the light emitted from the bulb twice (see Fig. 8B). First refraction (total internal reflection) at point a
The light is then refracted a second time at point b) to focus the light in the direction of the optical axis of the lamp. Due to this prism cut, the light incident on the range _S1 of the second inner lens 15 is transferred to the range S1 of the first inner lens 14.
It is bent to be incident on T ₁ . Also, range S ₂
The incident light is within the range of the first inner lens 14.
It is bent to be incident on T ₂ . The back surface of the first inner lens 14 (the second inner lens 15
In the range T ₁ and the range T ₂ of the surface facing the second inner lens 15, there are prism cuts for controlling the optical axis (primary refraction cut 14A and total reflection prism cut 14B) in the opposite direction to the prism cut for controlling the optical axis of the second inner lens 15. These prism cuts control the incident light from the second inner lens 15 so that it is bent in the direction of the optical axis of the lamp (see FIG. 3).
As a result, the light incident on the second inner lens 15 is all within the range T ₁ of the first inner lens 14,
It is radiated outward from T ₂ . In other words, the range can be effectively covered without being obstructed by the reflex reflector.
It is radiated outward from T ₁ and T ₂ .

The shape of the optical axis control prism cut formed on the first and second inner lenses 14 and 15 is determined by the following calculation formula. However, the cutlet is
It should be 0.3mm or less.

As shown in Figure 2, the light axis direction is the y-axis,
A first inner lens 14 and a second inner lens 15 are provided parallel to a plane normal to the y-axis. The distance from the y-axis to the end of the first inner lens is A, and the distance from the y-axis to the end of the second inner lens 15 is
Assuming that the distance to the end of is B, and the interval between the two inner lenses is C, the following relational expression holds true from FIG.

tan α=B-A/C=A/D However, A<B, and the light shielding part is set in the range (B-A).

From this, D=BC/B-A...(1) α _x at point x=Xb of the second inner lens 15 is α _x = tan ^-1 (X _b /D)...(2) First inner lens α _x at point x=Xa in 14 is α _x = tan ^-1 (X _a /D−C) …(3) Enlargement of the optical axis control prism cut 15A of the primary refraction cut in the range of α _x ≦33° The diagram is shown in Figure 8A.

If the refractive index of the lens is n, then from Figure 8 A, n = sin (π/2 - (π/2 - α _x - θ)) / sin θ = sin (α _x + θ) / sin θ = sin α _x cos θ＋cos α _x sin θ／sin θ ＝sin α _x ／tan θ＋cos α _x θ＝tan ^-1 (sin α _x ／n−cos α _x ) ...(4) Also, the range of α _x > 33° is calculated by formula ( 5) performs a prism cut for controlling the optical axis of the total reflection cut.

β＝tan ^-1 (sin ε−nsin δ／cos ε＋ncos δ)…(
5) However, δ=90°−2γ, ε=90°α _x .

Figures 4 to 6 show other embodiments of the present invention. Figures 4 and 5 show a lamp using a parabolic reflector, and Figure 6 shows a lamp using a Fresnel cut inner lens. This is the case with lighting equipment.

In FIG. 4, 21 is a housing whose rear inner surface is a parabolic reflector, 22 is a bulb, 23 is an outer lens, 24 is a first inner lens,
25 is a second inner lens, and 26 is a rim that covers the outer periphery of the outer lens 13. This rim 26 becomes a light shielding part within the effective surface B of the reflecting mirror, but due to the arrangement of the first and second inner lenses 24 and 25, the light from the reflecting mirror is not blocked by the rim 26 and is emitted from the range A. be done.

FIG. 5 shows a case in which the light emitting surface is enlarged, contrary to FIG. , second inner lens 2
The positions of 4' and 25' are reversed.

In FIG. 6, 21 is a housing, 32 is a bulb, 33 is an outer lens having a reflex reflector 33A from the side, 34 is a first inner lens, 35 is a second inner lens, and both inner lenses 34 , 35, no optical axis control prism cut is provided. In this case as well, the light emitted from the bulb 32 is effectively utilized without being blocked by the reflex reflector 33A.

〔effect〕

As described above, according to the present invention, two inner lenses are arranged approximately in parallel to refract the light emitted from the bulb so as to avoid the light shielding part (reflex reflector, rim, etc.) of the outer lens.
Even if there is a light shielding part in front of the lamp, effective use of the emitted light can be achieved, and a reduction in luminous intensity of the lamp can be reduced. In addition, the prism cut for controlling the optical axis of the inner lens has an extremely small pitch of 0.3 mm or less, which allows the inner lens to be made thinner and prevents interference with the fisheye cut pitch of the outer lens (moiré phenomenon). Furthermore, since the pitch of the inner lens is difficult to see through the outer lens, the appearance of the lamp also improves. Furthermore, it is possible to increase the brightness of the lens light emitting surface and to enlarge the lens light emitting surface.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of a vehicle lamp according to the present invention, FIG. 2 is an explanatory diagram of the arrangement relationship of the first and second inner lenses in the same embodiment, and FIG. An enlarged view of part X, Figures 4 to 6 are cross-sectional views showing other embodiments of the present invention, Figure 7 is a cross-sectional view of a conventional example, and Figures 8 A and 8 are primary refraction cuts and total internal reflection. Figures 9 to 12 are explanatory diagrams showing the shape of the prism cut and the respective light paths, and the details of the two inner lenses in Figures 1 and 4 to 6 are explanatory diagrams showing the configuration. be. 11...Housing, 12...Valve, 13...
...Outer lens, 14...First inner lens, 15...Second inner lens, 14A and 15A...Primary refraction cut, 14B and 15B...
...Total reflection prism cut.

Claims (1)

[Scope of utility model registration request] A predetermined calculation formula is used in a vehicle lamp in which an outer lens with a part of the light-shielding part is placed on the front of the housing, and an inner lens is provided inside the outer lens to condense the light emitted from the bulb in the direction of the lamp's optical axis. Using two inner lenses each having an optical axis control prism cut consisting of a primary refraction cut and a total reflection prism cut whose shapes are determined by A vehicular lamp characterized in that the emitted light directed from the bulb towards the light shielding part is refracted outside the light shielding part and then directed in the direction of the optical axis of the lamp.