JP3252654B2 - Headlight - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a traveling light distribution pattern by a light beam emitted from a main filament,
The present invention relates to a headlamp using a double filament light source bulb, in which a passing light distribution pattern is formed by a light beam emitted from a subfilament.

[0002]

2. Description of the Related Art FIG. 7 is a sectional side view showing a conventional example of this type of headlight. However, since the constituent elements of the headlight according to the present invention do not appear in the side view, FIG. 7 can also be viewed as a cross-sectional side view of an embodiment described later. A reflector 3 is tiltably installed in a lamp room surrounded by a lamp housing 1 and a front lens 2. 3a, 3a '
Is a paraboloidal reflective surface, and 3b and 3b 'are ineffective portions. A light source bulb 4 is provided so as to position the filament near the focal point of the paraboloid of revolution. 5 m is a main filament for forming a suitable light distribution pattern (hereinafter referred to as a traveling light distribution pattern) when there is no oncoming vehicle, and is arranged substantially parallel to the optical axis Z. 5s is a subfilament for forming a suitable light distribution pattern (hereinafter referred to as a passing light distribution pattern) when there is an oncoming vehicle, and is disposed substantially parallel to the optical axis Z. Therefore, the main filament 5m and the sub-filament 5s are substantially parallel to each other. Since the main filament 5m is located near the focal point of the paraboloidal reflecting surfaces 3a and 3a ', the light beam emitted from the main filament 5m and reflected by the paraboloidal reflecting surfaces 3a and 3a' Becomes a parallel light beam substantially in the optical axis Z direction, and becomes a traveling beam suitable for forming a traveling light distribution pattern. Since the sub-filament 5s is disposed slightly ahead of the main filament 5m, the light beam emitted from the sub-filament 5s and reflected by the paraboloidal reflecting surfaces 3a, 3a 'has a slight diffusivity. It becomes a substantially parallel light beam. The slightly diffused substantially parallel light beams illuminate a wide area in front of the traveling road. However, there are the following problems when used as a low beam for forming a low light distribution pattern.

In order not to dazzle oncoming vehicles,
It is necessary not to irradiate above the horizontal line on the side of the opposite lane, and this is stipulated. For this reason, a shade (not shown) is provided diagonally below the sub-filament 5s so that the reflected light from the paraboloid-shaped reflecting surfaces 3a and 3a 'does not irradiate the upper side on the opposite lane. Whether the diagonally lower part is the lower left part or the lower right part depends on whether the traffic regulation is left-hand traffic or right-hand traffic.

[0004]

As described with reference to FIG. 7, when a shade is provided to form a passing light distribution pattern, a part of the light beam emitted from the subfilament is blocked, so that the light beam is effectively used. The rate drops. For this reason, even if the shade is not provided, it is possible to improve the effective utilization rate of the luminous flux by not irradiating above the horizontal line on the side of the oncoming lane, and to make the dimming by the front lens 2 light (ideally, A reflector having a reflecting surface composed of a free-form surface formed by combining a plurality of paraboloids of revolution is known in order to allow a transparent lens to suffice (for example, a vehicle described in Japanese Patent Publication No. 6-44401). head lamp). In this known technique, the paraboloid of revolution forming the reflecting surface of the reflector is divided into a plurality of parts by design, and the focal length of the paraboloid of revolution is slightly changed for each section, and By slightly tilting the axis of symmetry, the optical characteristics of a reflector consisting of a simple paraboloid of revolution are modified. However, since the correction is minute, the optical axis and the focal point can be approximately determined without any strictness. Further, when the respective focal positions of the plurality of paraboloids of revolution provided with the plurality of sections substantially coincide with each other, this can be treated as a pseudo focus. The free-form surface in the present invention is not an unconditional free-form surface, but a surface that reflects a light beam emitted from a subfilament into a passing beam without a shade by combining a plurality of paraboloids of revolution as described above. Say.
The light reflected by the reflecting surface having the free-form surface may be used as it is as a passing beam, or the reflected light may be modulated by the front lens 2. However, since the reflected light beam is already similar to the desired low beam, when the reflector having the reflecting surface of the free-form surface is used, light adjustment by the front lens 2 is sufficient.

A reflector having a reflecting surface composed of a free-form surface has the above-mentioned advantages, and is expected to become the mainstream in the near future. Have.

When a shade is provided on the subfilament, a portion corresponding to the shadow of the shade is formed on the reflection surface of the reflector. When the sub-filament is turned on, this portion does not receive the light beam, so that no reflected light is emitted. However, when the main filament is turned on, the above-described portion receives the light beam and reflects it. Therefore, the above-mentioned portion becomes an ineffective portion when the sub-filament is turned on to form a passing beam, and functions as a reflection surface when the main filament is turned on to form a traveling beam. By utilizing such an effect, when configuring a reflecting surface composed of a free-form surface, if a paraboloid of revolution corresponding to the above-mentioned portion is appropriately set among a plurality of paraboloids of revolution, the passing beam is affected. The traveling beam can be corrected without any trouble. When the shade is provided diagonally below the sub-filament by such an action, not only is it easy to design a passing beam that forms a light distribution pattern for passing, but also it is possible to design a traveling beam that forms a light distribution pattern for traveling. It is easy, for example, and the area of the maximum illuminance (hereinafter referred to as a hot zone) in the traveling light distribution pattern can be designed and adjusted by the reflected light from the above-mentioned portion.

However, if the shade is eliminated by using a reflector having a reflecting surface consisting of a free-form surface, the above-mentioned portion (the light beam emitted from the subfilament is blocked by the shade and does not enter, and only the light beam emitted from the main filament is reflected) Thus, the portion that can correct the hot zone of the traveling light distribution pattern is eliminated. Therefore, it is necessary to convert the passing beam and the traveling beam by using the same free-form reflecting surface and switching the sub-filament and the main filament by blinking. For this reason, it is not possible to correct the hot zone of the light distribution pattern for traveling by using the portion where the reflection surface is irradiated only by the light emitted from the main filament. Further, since both the traveling beam and the passing beam must be formed by a reflector having a reflecting surface having the same free-form surface, if the hot zone of the traveling light distribution pattern cannot be corrected as described above, the passing beam cannot be passed. The design freedom for forming the hot zone of the light pattern is also limited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has been developed using a double filament type light source bulb of a type in which a traveling beam and a passing beam are converted by blinking switching between a main filament and a subfilament. A headlight that can be easily improved to set the hot zone of the traveling light distribution pattern formed by the traveling beam and the hot zone of the passing light distribution pattern formed by the passing beam at appropriate positions. The purpose is to provide.

[0009]

The basic principle of the present invention created to achieve the above object will be described with reference to FIG.
The following is a description with reference to FIG. This figure is a side view cut by a vertical plane passing through the optical axis Z of the headlamp, in which the subfilament 5s is located substantially on the optical axis, and the main filament 5m is located below and substantially parallel to the optical axis. Although it is shown that they are arranged, the positional relationship between these two filaments in the depth direction of the paper cannot be read from FIG. Conventionally, the main filament 5
m is disposed immediately below the subfilament 5s. That is, the main filament 5m is also the sub-filament 5
s was also disposed on a vertical plane passing through the optical axis Z. As for the outline of the present invention with reference to FIG.
And the sub-filament 5s are displaced in the depth direction in the drawing. When viewed in the direction opposite to arrow Z from the front of the headlamp, the main filament 5m is located below or to the left of the sub-filament 5s. Whether to dispose on the lower right or on the lower left is determined by whether the traffic regulations of the country where the vehicle equipped with the headlight travels are left-hand traffic or right-hand traffic. Details will be described later. As a specific configuration based on the above principle, the headlamp according to the present invention includes a reflector having a reflection surface formed of a paraboloid of revolution or a reflection surface formed of a free-form surface obtained by combining a plurality of paraboloids of revolution. Light source bulb having a main filament arranged substantially parallel to the optical axis of the reflector to form a light distribution pattern for traveling, and a subfilament arranged substantially parallel to the optical axis of the reflector to form a light distribution pattern for passing And a headlight comprising:
When viewed from the front of the headlight, the
Filament is located diagonally below the subfilament
And a main filament and a sub-filament of the light source bulb.
The light emission with the reflector
The hot zone of the emitted luminous flux is left to the vehicle running direction
It is characterized by switching to the right .

[0010]

According to the above-mentioned means, since the main filament and the sub-filament are shifted to the left and right while being substantially parallel to the optical axis, the main light projecting direction of the light beam emitted from the main filament and reflected by the reflector is reflected. And the main light projecting direction of the light beam emitted from the sub-filament and reflected by the reflector is formed so as to swing right and left. On the other hand, it is desirable that the traveling light distribution pattern formed by the traveling beam used when there is no oncoming vehicle irradiates the center of the road. For example, under traffic regulations for left-hand traffic, the car travels on the left half of the road, so it is necessary to project light slightly to the right compared to the center line of the car body to illuminate the center of the road. Becomes Similarly, in the case of right-hand traffic, it is necessary to project light slightly to the left. To summarize this,
It is desirable that the traveling beam be deflected to the opposite lane.
In addition, the passing light distribution pattern formed by the passing beam used when there is an oncoming vehicle needs not to swing toward the oncoming lane in front of the road so as not to dazzle the oncoming vehicle. Summarizing the above, the fact that the main beam and the sub-filament are shifted to the left and right, and the traveling beam and the passing beam swing right and left, is a double light distribution pattern for traveling and a passing light distribution pattern. This is convenient for conversion by operating a changeover switch of a filament light source bulb. That is, when the main filament and the sub-filament are switched, the main light projecting direction swings left and right, and the hot zone formed near the center of the projected light beam moves left and right. Whether the main light emitting direction when the main filament is turned on swings right or left compared to the main light emitting direction when the sub filament is turned on is determined by arranging the main filament below and to the left of the sub filament. It can be selected arbitrarily in terms of design depending on whether it is located at the lower right or in the lower right.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, referring to FIGS.
An embodiment of the present invention will be described. FIG. 1 shows a double filament type light source bulb used in a headlight according to one embodiment of the present invention, (A) is a perspective view with a coordinate axis added, and (B) is a main filament and a sub filament. Is a rear view as viewed in the direction of arrow Z, and FIG.
It is the side view seen in the direction. This embodiment is an example in which the vehicle is adapted to the traffic rules of the left-hand traffic.
The configuration is bilaterally symmetric with respect to the −Z plane. (A) The light source bulb 4 shown in the figure is used in combination with a reflector having a reflecting surface composed of a free-form surface obtained by combining a plurality of paraboloids of revolution, and the Z axis indicates an approximate optical axis of the free-form surface. , The arrow Z corresponds to the light projection direction. The X axis is a horizontal axis passing through the pseudo focus of the free-form surface, and the Y axis is a vertical axis. (B)
As shown in the drawing, the main filament 5m is located below the sub-filament 5s by the distance Ly and to the left by the distance Lx. However, this drawing shows arrow Z
In the front view (not shown) viewed from the front of the headlamp in the direction of arrow Z ', the main filament 5 is shown.
m is located to the right by the distance Lx with respect to the subfilament 5s.

(C) As shown in the figure, the center point 5m _{1 in} the front-rear direction of the main filament 5m is longer than the center point 5s ₁ in the front-rear direction of the subfilament 5s by a distance Lz.
Only located behind. Then, the front end 5m ₂ main filament 5m is 'located further forward than the rear end 5s ₂ sub filament 5s pseudo focal position F' pseudo focal position F is located behind.

FIG. 2 is a schematic diagram in which an optical path arrow is added when a light beam emitted from a subfilament of a light source bulb configured as in the embodiment shown in FIG. 1 is reflected by a paraboloid of revolution. FIG. The main filament 5m is indicated by a virtual line. A light beam emitted from the subfilament 5s as shown by an arrow a and reflected at one point in the upper half of the paraboloid reflector 6 as shown by an arrow a 'is provided on a screen provided in front of the headlight ( An image 7a of the sub-filament is formed on the sub-filament (not shown). Similarly,
The outgoing / reflected light beams shown by arrows b and b 'represent the subfilament image 7b, the outgoing / reflected light beams shown by arrows c and c' represent the subfilament image 7c, and the outgoing / reflected light beams shown by arrows d and d '.
The reflected light flux connects the sub-filament images 7d.
The optical path arrows and the four sub-filament images 7a to 7d of the emission / reflection light of the four systems described above with reference to FIG.
Although the luminous flux reflected at four points on the reflecting surface of the paraboloid of revolution 6 is illustrated as an example, in reality, reflection is performed at all points on the reflecting surface, and the light is reflected on a screen (not shown). Are formed with an infinite number of sub-filament images (not shown), and these are combined to form a light distribution area 7 for passing beams. The innumerable sub-filament images overlap each other near the center of the light distribution area 7 of the passing beam to form a hot zone. The illustrated line V is a vertical line passing through an intersection O between the optical axis Z and the screen, and the line H is also a horizontal line. The hot zone is formed on the vertical line V on the screen because the subfilament 5s is not deviated left and right as compared with the optical axis Z. FIG. 3A is a table showing the light distribution area 7 and the hot zone 7 'of the low beam, which are symmetrical about the vertical line V.

FIG. 4 is a schematic perspective view in which the light beam emitted from the main filament shown in FIG. 1 is reflected by a paraboloid of revolution similar to that shown in FIG. It is. The subfilament 5s is indicated by a virtual line. Main filament 5m
From the arrow to the reflecting surface of the paraboloid reflector 6,
To h, and reflected as shown by arrows e 'to h', respectively, form main filament images 8e to 8h. When viewed in the direction of arrow Z, the main filament is 5 m.
Is shifted to the left compared to the optical axis Z, the light distribution area 8 of the traveling beam in which the main filament images are integrated, and the overlapping portion (hot zone) of each main filament image is a vertical line V on the screen. Formed to the right. FIG. 3B is a table showing the light distribution area 8 of the traveling beam and the hot zone 8 ′, which is deviated rightward with respect to the vertical line V. Considering FIGS. 3 (A) and 3 (B), it is possible to illuminate the front of the headlight by simply switching the sub-filament 5s and the main filament 5m by using the same rotating parabolic reflector 6. The light distribution area 7 and the hot zone 7 'of the passing beam and the traveling beam light distribution area 8 and the hot zone 8' for irradiating the headlight to the front right are converted and moved to the left and right. You can choose. The traveling beam distribution area 8 and the hot zone 8 'shown in FIG. 3B are located on the right side, and thus are suitable as traveling beams for left-hand traffic. (A) Since the light distribution area 7 of the low beam in the figure irradiates the area above the horizontal line H, it is not used as it is. However, a shade is provided diagonally below the sub-filament and the right half of the area above the horizontal line H is provided. Shielding provides a suitable low beam. In the examples shown in FIGS. 3A and 3B, a rotating paraboloidal reflector is used, so that the shade must be used in combination. However, the light emitting direction is automatically changed when the main filament and the subfilament are switched on and off. The effect of swinging left and right is obtained.

FIG. 5 is a schematic perspective view to which an optical path arrow is added when the light beam emitted from the subfilament of the light source bulb configured as shown in FIG. 1 is reflected by the free-form surface reflector. The main filament 5m is indicated by a virtual line. Light beams incident on the free-form surface reflector 9 as indicated by arrows i, j, k and m from the subfilament 5s and reflected as indicated by arrows i ', j', k 'and m' are respectively sub-filament images 10i and 10j, 10
k, 10m. The above four sub-filament images are exemplifications. Actually, an innumerable sub-filament image (not shown) is combined to form the light distribution area 10 of the passing beam. The free-form surface reflector 9 has a combination of a plurality of paraboloids of revolution, and the light distribution area 10 of the low-pass beam does not depend on the shade as shown in FIG.
As shown in the figure, the right side of the vertical line V is cut off above the horizontal line H, and it is suitable as a passing beam under traffic regulations for driving on the left. FIGS. 6 and 3D show a state in which the main filament 5m is turned on using the same free-form surface reflector 9 as in the embodiment of FIGS. 5 and 3C described above. (See FIG. 6) The main filament 5m is deviated leftward from just below the optical axis Z (when viewed in the direction of the arrow Z). For this reason, the main filament 5m
Free-form surface reflector 9 as indicated by arrows n, p, q, r
Of the main filament images 11n, 11p, 11 near the right side of the vertical line V on the screen (not shown).
Since q and 11r are connected to form a hot zone 11 'on the right side of the vertical line V as shown in FIG. 3 (D), it is suitable as a traveling beam under traffic regulations for traveling on the left as it is. Main filament 5 in this embodiment
m is disposed behind the sub-filament 5s by a distance Lz as shown in FIG. 1C, and this distance Lz is set within a range of 0 to 4 mm in the case of a normal automotive headlamp. It is appropriate to do so. When the free-form surface reflector 9 is configured so as to reflect the light beam emitted from the subfilament 5s and form the light distribution area 10 of the low beam as shown in FIG. When set to be large, the light distribution area 11 of the traveling beam in FIG. 3D can be expanded upward. In order to show the relationship between the light distribution area 11 of the traveling beam and the hot zone 11 'and the road, the center line 12 when traveling on the left side is indicated by a dotted line, and the left and right road shoulders 13 and 13' are indicated by broken lines, respectively, in FIG. D). Since the light distribution area 11 of the traveling beam and the hot zone 11 'are closer to the right than the vertical line V corresponding to the center line based on the own vehicle, when traveling on the left side of the road where there is no oncoming vehicle, It can be easily understood from FIG. 3D that the front of the road can be suitably illuminated from a long distance to a short distance.

[0016]

As described above with reference to the embodiments,
When the present invention is applied to a headlamp using a double filament type light source bulb, the main filament and the subfilament are shifted to the left and right while keeping substantially parallel to the optical axis. The main light projecting direction of the light beam reflected by the sub-filament and the main light projecting direction of the light beam emitted from the sub-filament and reflected by the reflector are formed so as to be swung right and left. On the other hand, it is desirable that the traveling light distribution pattern formed by the traveling beam used when there is no oncoming vehicle irradiates the center of the road. For example, under traffic regulations for left-hand traffic, the car travels on the left half of the road, so it is necessary to project light slightly to the right compared to the center line of the car body to illuminate the center of the road. become. Similarly, in the case of right-hand traffic, it is necessary to project light slightly to the left. In summary, it is desirable that the traveling beam be deflected to the opposite lane. In addition, the passing light distribution pattern formed by the passing beam used when there is an oncoming vehicle needs not to swing toward the oncoming lane in front of the road so as not to dazzle the oncoming vehicle.

Summarizing the above, the fact that the main beam and the sub-filament are shifted to the left and right and the traveling beam and the passing beam are swaying to the left and right is the fact that the traveling light distribution pattern and the passing light distribution pattern are different. Is advantageously converted by operating the changeover switch of the double filament light source bulb. That is, when the main filament and the sub-filament are switched on and off, the main light projecting direction swings right and left, and the hot zone formed near the center of the projected light beam moves left and right. Whether the main light emitting direction when the main filament is turned on swings right or left compared to the main light emitting direction when the sub filament is turned on is determined by arranging the main filament below and to the left of the sub filament. Since it can be arbitrarily selected in terms of design depending on whether it is located at the lower right or in the lower right, it can be appropriately set according to the traffic regulations of the destination country.

[Brief description of the drawings]

FIG. 1 shows a double filament type light source bulb used in a headlight according to one embodiment of the present invention, (A) is a perspective view with a coordinate axis added, and (B) is a main filament and a sub filament. FIG. 3C is a rear view of the filament as viewed in the direction of arrow Z, and FIG.

FIG. 2 is a schematic perspective view to which an optical path arrow is added when a light beam emitted from a subfilament of a light source bulb configured as in the embodiment shown in FIG. 1 is reflected by a rotary parabolic reflector; It is.

FIG. 3 is a table showing a light distribution pattern formed by a light beam emitted from the light source bulb configured as shown in FIG. 1, wherein (A) shows a light beam emitted from a sub-filament is a rotary parabolic reflector; (B) shows the light distribution area of the traveling beam formed when the light beam emitted from the main filament is reflected by the paraboloid of revolution, (C) shows the light distribution area of the low beam formed when the light beam emitted from the subfilament is reflected by the free-form surface reflector, and (D) shows the case where the light beam emitted from the main filament is reflected by the free-form surface reflector. The light distribution area of the traveling beam formed in the drawing is drawn.

FIG. 4 is a schematic perspective view to which an optical path when a light beam emitted from the main filament shown in FIG. 1 is reflected by a rotary paraboloid reflector similar to that shown in FIG. 2 is added.

FIG. 5 is a schematic perspective view to which an optical path arrow is added when a light beam emitted from a subfilament of the light source bulb configured as shown in FIG. 1 is reflected by a free-form surface reflector.

FIG. 6 is a schematic view in which an optical path arrow is added when a light beam emitted from a subfilament of a light source bulb configured as shown in FIG. 1 is reflected by a free-form surface reflector similar to that in FIG. It is a perspective view.

FIG. 7 shows a method in which a traveling beam is formed by a light beam emitted from a main filament and a passing beam is formed by a light beam emitted from a subfilament.
FIG. 9 is a vertical sectional view showing a conventional example of a headlamp using a double filament light source bulb.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Lamp housing, 2 ... Front lens, 3 ... Reflector, 3a, 3a '... Rotation parabolic reflective surface, 3b, 3b'
... Ineffective part, 4 ... Light source bulb, 4a ... Light shielding cap, 5m
… Main filament, 5m ₁ … Center of front and rear direction of main filament, 5m ₂ … Front end of main filament,
5s ... sub filament, 5s ₁ ... longitudinal center of the sub-filaments, 5s ₂ ... sub filament rear, 6
... Rotating parabolic reflector, 7 ... Light beam distribution area for passing beam, 7 '... Hot zone, 7a-7d ... Subfilament image, 8 ... Light distribution area for traveling beam, 8' ... Hot zone, 8e-8h ... Main Filament image, 9: free-form surface reflector, 10: light distribution area of low beam, 1
0 ': hot zone, 10i, 10j, 10k, 10m
.., Sub-filament image, 11: light distribution area of traveling beam, 11n, 11p, 11q, 11r: main filament image, 11 ': hot zone, 12: center line, 13, 13' road shoulder, F ': pseudo focus position.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI F21Y 101: 00

Claims (1)

(57) [Claims] 1. A reflection surface comprising a paraboloid of revolution or a plurality of
Reflective surface composed of free-form surfaces combining a number of paraboloids of revolution
A traveling light distribution disposed substantially parallel to the optical axis of the reflector;
A main filament forming a pattern, and
Light distribution for passing by being arranged almost parallel to the optical axis of the reflector
Light source bulb with subfilament forming pattern
And a headlight comprising:Said When viewed from the front of the headlight, the main filament
Is positioned diagonally below the subfilamentAnd Main filament and sub-filament of the light source bulb
By switching the light emission with the
Hot zone of the luminous flux
Configuration to switch A headlight characterized by the following.