JP2008074322A - Vehicular headlamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular headlamp capable of storing a light-receiving unit for detecting light from a preceding vehicle or an oncoming vehicle in a casing by a simple constitution. <P>SOLUTION: The vehicular headlamp 10 comprises a reflecting surface 12 for reflecting light from a light source 11 forwardly, a first driving means 16 for integrally and vertically rocking the light source and the reflecting surface, a casing 14 for surrounding the light source, the reflecting surface and the first driving means in a liquid-tight manner, a cover lens 15 for covering the open front side of the casing, and a control unit 19 for performing the drive control of the driving means arranged on the outer side of the casing, and further comprises a light-receiving unit 13 for detecting light from a preceding vehicle and/or an oncoming vehicle which is incident through an opening part formed at a part of the reflecting surface, and a second driving means 17 for vertically rocking the light-receiving unit. The vehicular headlamp 10 is constituted so that the control unit performs the drive control of the first driving means based on the detection signal from the light-receiving unit, and the irradiation angle of the light to be irradiated forward of the light irradiation direction from the light source via the reflecting surface is adjusted downwardly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle headlamp that is used, for example, as a headlamp or an auxiliary headlamp provided at the front of an automobile, and performs angle adjustment of a light distribution pattern particularly when a preceding vehicle or an oncoming vehicle is detected. It is related with the vehicle headlamp which made it.

Conventionally, such a vehicle headlamp is disclosed in, for example, Patent Document 1 and is configured as shown in FIG.
That is, in FIG. 2, a vehicle headlamp 1 includes a bulb 2 as a light source, a reflecting surface 3, a projection lens 4, a shutter 5, a driving means 6 for moving the shutter 5 in the vertical direction, and a preceding vehicle detection. The unit 7 and the oncoming vehicle detection unit 8 are configured.

  The bulb 2 is a bulb generally used for automobile headlamps or auxiliary headlamps, and is composed of a halogen lamp having a known configuration, a discharge lamp such as an HID (High Intensity Discharge), or the like.

The reflective surface 3 is composed of an elliptical reflective surface having a first focal point (rear focal point) F1 in the vicinity of the bulb 2 and a long axis extending substantially horizontally toward the front in the light irradiation direction. It is formed as a surface.
Here, the elliptical reflecting surface includes not only a spheroid and an elliptic cylinder but also a free-form surface based on an ellipsoid.

The projection lens 4 is composed of a convex lens, and its focal point on the light source side (rear side) is disposed in the vicinity of the second focal position F2 of the reflecting surface 3.
Thereby, the projection lens 4 collects light traveling forward from the bulb 2 or the reflecting surface 3 in the light irradiation direction, and irradiates the light forward in the light irradiation direction.

The shutter 5 includes a pair of upper and lower light shielding plates 5a and 5b positioned above and below the optical axis.
The lower light shielding plate 5a is disposed in the vicinity of the rear focal position of the projection lens 4, and forms a cut-off line by blocking part of the light incident on the projection lens 4 from the bulb 2 or the reflecting surface 3. However, a light distribution pattern suitable for the passing beam is formed.
The upper light-shielding plate 5b is disposed on the upper side of the optical axis and slightly forward of the light-shielding plate 5a, and blocks the illusion light above the optical axis.

  The driving means 6 is configured to move the light shielding plates 5a and 5b of the shutter 5 described above up and down, respectively, and based on detection signals from a preceding vehicle detection unit 7 and an oncoming vehicle detection unit 8 which will be described later. The light shielding plates 5a and 5b of the shutter 5 are moved up and down to change the irradiation direction downward.

  The preceding vehicle detection unit 7 includes an optical system 7a such as a prism and a lens, and a light receiving unit 7b. The brightness of the illumination lamp of the preceding other vehicle is detected by the light receiving unit 7b via the optical system 7a. It detects and the presence of a preceding vehicle is detected.

  The oncoming vehicle detection unit 8 includes an optical system 8a such as a lens, and a light receiving unit 8b. The brightness of the headlight of the oncoming vehicle is detected by the light receiving unit 8b via the optical system 8a. Thus, the presence of an oncoming vehicle is detected.

According to the vehicle headlamp 1 having such a configuration, when power is supplied to the bulb 2 from the outside, the bulb 2 emits light. The light emitted from the bulb 2 is reflected directly or by the reflection surface 3, proceeds forward in the light irradiation direction toward the vicinity of the second focal point F 2 of the reflection surface 3, and is focused by the projection lens 4 while being focused. Irradiated forward in the irradiation direction.
At that time, a part of the light is blocked by the shutter 5, thereby forming a cutoff, and a light distribution pattern of a passing beam is formed as shown by a solid line in FIG.

  For example, when the preceding vehicle detection unit 7 detects the preceding vehicle, the drive unit 6 moves the shutter 5 downward, so that the cut-off line in the light distribution pattern is from C1 to C2, as shown by the dotted line in FIG. It will be displaced downward.

In the case of a vehicle headlamp of the type in which the projection lens is omitted and the reflecting surface is a parabolic reflecting surface, a unit consisting of a bulb and a reflecting surface is arranged so as to be swingable up and down in the housing. When a preceding vehicle or an oncoming vehicle is detected, the light distribution pattern is displaced up and down by swinging and adjusting the unit in the vertical direction.
Japanese Patent Laid-Open No. 01-278848

  In the two types of vehicle headlamps described above, the detection unit for detecting the preceding vehicle and the oncoming vehicle is configured as an independent unit separate from the vehicle headlamp. It is impossible to incorporate it in a limited space in the lamp housing. For this reason, these detection parts must be arrange | positioned outside the housing | casing of a vehicle headlamp, and it is necessary to ensure the space for installing these detection parts.

  Moreover, since these detection parts need to take in light from the outside, it is necessary to employ | adopt a waterproof structure. Therefore, since the structure becomes complicated, the weight increases and the cost increases.

  In view of the above, an object of the present invention is to provide a vehicle headlamp in which a light receiving unit that detects light from a preceding vehicle or an oncoming vehicle is housed in a housing with a simple configuration.

  According to the present invention, the object is to integrate the light source, the concave reflecting surface forward in the light irradiation direction, and the light source and the reflecting surface so as to reflect light from the light source forward in the light irradiation direction. A first driving means that swings up and down in a vertical direction, and the light source, the reflecting surface, and the first driving means are liquid-tightly surrounded, and a front surface is opened, and a front surface of the housing is covered. The vehicle headlamp includes a cover lens that is closely attached and a control unit that drives and controls the driving unit disposed outside the housing, and is provided on a part of the reflecting surface. A light receiving unit that is disposed behind the formed opening and detects light from a preceding vehicle and / or an oncoming vehicle that enters through the opening from the front of the light irradiation direction, and swings the light receiving unit in the vertical direction. Second drive means, and the control unit receives the second drive means. Based on the detection signal from the unit, the first driving means is driven and controlled, and the irradiation angle of the irradiation light irradiated from the light source to the front of the light irradiation direction through the reflecting surface is adjusted with respect to the vertical direction. This is achieved by a vehicle headlamp characterized in that the light distribution pattern is displaced downward.

  The vehicle headlamp according to the present invention preferably further includes vehicle attitude angle detection means, and the control unit controls driving of the second drive means based on a detection signal from the vehicle attitude angle detection means. Thus, regardless of the attitude angle of the vehicle, the detection direction of the light receiving unit is held in the horizontal direction.

  In the vehicle headlamp according to the present invention, preferably, the control unit drives and controls the first driving unit based on the detection signals from the light receiving unit and the vehicle attitude angle detecting unit, so that the irradiation angle of the irradiation light is set. Adjust based on the horizontal direction.

  In the vehicle headlamp according to the present invention, preferably, the control unit drives and controls the first driving means and / or the second driving means at predetermined time intervals or continuously.

  In the vehicle headlamp according to the present invention, preferably, the control unit drives and controls the first driving unit corresponding to the light reception intensity of the light receiving unit, so that the irradiation light is continuously or stepwise. Displace the irradiation angle.

  In the vehicle headlamp according to the present invention, preferably, the control unit drives and controls the first driving unit based on further vehicle information and surrounding information.

  In the vehicle headlamp according to the present invention, preferably, the light emitting unit is detachably and liquid-tightly attached to the housing.

According to the above configuration, the light source emits light by power supply from the outside, and the light emitted from the light source is reflected directly or by the reflecting surface and is irradiated forward in the light irradiation direction through the cover lens.
During normal traveling, that is, when light from a preceding vehicle or an oncoming vehicle is not incident on the light receiving unit, the control unit drives and controls the first driving means. Accordingly, the irradiation angle of the irradiation light is adjusted to be substantially horizontal, and the irradiation light to the front is irradiated in the substantially horizontal direction.

When light from a preceding vehicle or an oncoming vehicle enters the light receiving unit, the light receiving unit detects this light and sends a detection signal to the control unit.
Thus, the control unit controls the first drive unit to adjust the irradiation angle of the irradiation light slightly downward, and irradiates the irradiation light forward slightly downward toward the front of the light irradiation direction. To do. Therefore, the light distribution pattern by the irradiation light is displaced downward, and is adjusted so that it does not become dazzling light with respect to the preceding vehicle or the oncoming vehicle.

  Furthermore, a vehicle attitude angle detection unit is provided, and the control unit drives and controls the second driving unit based on a detection signal from the vehicle attitude angle detection unit, and receives light regardless of the vehicle attitude angle. When the detection direction of the unit is held in the horizontal direction, the detection direction of the light receiving unit is always held in the horizontal direction even if the vehicle headlamp is inclined due to a change in the attitude angle of the vehicle itself. Thereby, for example, the light from the preceding vehicle and the oncoming vehicle can be reliably detected without being affected by the light of various lights such as street lights.

  When the control unit drives and controls the first drive unit based on detection signals from the light receiving unit and the vehicle attitude angle detection unit and adjusts the irradiation angle of the irradiation light with reference to the horizontal direction, the vehicle Even if the vehicle headlamp tilts due to a change in the attitude angle of the vehicle itself, the irradiation angle of the irradiation light is always adjusted by the first driving means with reference to the horizontal direction. As a result, even if the attitude angle of the vehicle itself changes, the light distribution pattern of the irradiation light emitted toward the front of the light irradiation direction can be adjusted with reference to the actual horizontal direction, so It can be surely prevented from giving a dazzling light to the car.

  When the control unit controls the first driving unit and / or the second driving unit at predetermined time intervals or continuously, the irradiation angle of the irradiation light is always or substantially always appropriate. Can be adjusted to.

  The control unit drives and controls the first driving unit corresponding to the light receiving intensity of the light receiving unit. As a result, when the irradiation angle of the irradiation light is displaced continuously or stepwise, depending on the distance to the preceding vehicle and the oncoming vehicle and the approaching situation, the illusion light is emitted from these preceding and oncoming vehicles. In order to avoid this, the control unit can adjust the irradiation angle of the irradiation light.

  When the control unit further drives and controls the first driving means based on other vehicle information and surrounding information, for example, vehicle information such as vehicle speed and steering angle, and roads such as suburban roads and city roads. Based on the information or weather information, the control unit can always appropriately adjust the irradiation angle of the irradiation light corresponding to the information.

  When the light receiving unit is detachably and liquid-tightly attached to the housing, when only the light receiving unit fails, only the light receiving unit can be easily replaced. Further, since the light receiving unit is liquid-tightly attached to the casing, a waterproof structure in the casing can be secured.

  Thus, according to the present invention, it is possible to provide a vehicle headlamp in which a light receiving unit for detecting light from a preceding vehicle or an oncoming vehicle is housed in a housing with a simple configuration.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIG.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

[Example 1]
FIG. 1 shows the configuration of a first embodiment of a vehicle headlamp according to the present invention.
In FIG. 1, a vehicle headlamp 10 is a headlamp of an automobile, and includes a bulb 11 as a light source, a reflecting surface 12, a light receiving unit 13, a housing 14 surrounding them, a cover lens 15, First driving means 16 for swinging the reflecting surface 12 in the vertical direction, second driving means 17 for swinging the light receiving unit 13 in the vertical direction, vehicle attitude angle detection means 18, and these first driving means 16 and the control part 19 which drives and controls the 2nd drive means 17 is comprised.

  The bulb 11 is a bulb generally used for an automobile headlamp or an auxiliary headlamp, and is composed of an incandescent bulb such as a halogen bulb having a known configuration, a discharge lamp such as an HID, and the like. The axis O is arranged almost horizontally toward the front in the light irradiation direction, is fixedly held to the reflecting surface 12 by the socket 11a, and is supplied with power from the outside.

The reflection surface 12 is formed in a concave shape so as to reflect the light L1 from the bulb 11 forward in the light irradiation direction, and its focal position F is located in the vicinity of the light emitting point of the bulb 11. Thus, it is configured as a parabolic reflecting surface.
Here, the paraboloidal reflecting surface includes not only a rotating paraboloid but also a free-form surface based on a paraboloid.

The reflection surface 12 is supported so as to be swingable in the vertical direction with respect to the housing 14.
Specifically, the lower end of the reflection surface 12 is supported by a ball nut or the like so as to be swingable with respect to the bottom surface of the housing 14.
Furthermore, the reflection surface 12 includes an opening 12b penetrating in the front-rear direction in the lower region.

The light receiving unit 13 is disposed behind the opening 12 b of the reflecting surface 12 and is supported to be swingable with respect to the housing 14.
Specifically, the light receiving unit 13 includes a lens 13b and a light receiving element 13c in a socket 13a, and the socket 13a is detachably attached to the base 13d.
The lower end of the base 13d is supported by a ball nut or the like so as to be swingable in the vertical direction with respect to the back surface 14a of the casing 14.

Further, the socket 13a extends rearwardly through the back surface 14a of the housing 14, and is provided with a waterproof cover 13e made of a flexible elastic material such as EPDM (Ethylene Propylene Diene Monomer). Even when rocking with respect to the back surface 14a, it is always liquid-tight.
As a result, the light receiving unit 13 detects the preceding vehicle or the oncoming vehicle when the light L2 from the tail lamp of the preceding vehicle incident from the front or the light L2 from the headlamp of the oncoming vehicle enters the light receiving element 13b. Thus, a detection signal is sent to the control unit 19.

  The casing 14 is made of a light shielding material so as to liquid-tightly surround the bulb 11, the reflecting surface 12, and the light receiving unit 13, and the front surface is open. The casing 14 is incorporated on the left and right of the front part of the automobile, for example.

The cover lens 15 is made of a translucent material, and is configured to liquid-tightly close the open end of the front surface of the casing 14 described above.
Thereby, the inside of the housing 14 is configured as a waterproof structure.

In the illustrated case, the first driving means 16 is provided at the upper part of the back surface 14a of the casing 14, and the actuator 16a extends through the back surface 14a toward the front in the horizontal direction, and the reflecting surface. 12 is connected to the upper end.
In the first driving means 16, a driving circuit 16 b that drives the actuator 16 a is driven and controlled by the control unit 19. As a result, the actuator 16a moves in the left-right direction in FIG. 1 to swing the reflecting surface 12 in the up-down direction.

In the illustrated case, the second driving means 17 is disposed above the waterproof cover 13e of the light receiving unit 13 on the back surface 14a of the casing 14, and the actuator 17a is directed forward in the horizontal direction. It extends through the back surface 14 a and is connected to the upper end of the base 13 d of the light receiving unit 13.
The second drive means 17 is driven and controlled by a control unit 19 in a drive circuit 17b that drives an actuator 17a. As a result, the actuator 17a moves in the left-right direction in FIG. 1 to swing the light receiving unit 13 in the up-down direction.

The vehicle attitude angle detection means 18 detects a three-dimensional attitude angle of a vehicle such as a gyro, for example, and is attached to any part of the body of an automobile.
The vehicle posture angle detection means 18 detects the posture angle of the vehicle body at that time, and sends a detection signal to the control unit 19 when the vehicle body posture angle changes.

The control unit 19 drives and controls the first drive unit 16 and the second drive unit 17 based on the detection signal from the light receiving unit 13 and the detection signal from the vehicle attitude angle detection unit 18. Thereby, the bulb | ball 11 and the reflective surface 12 are rock | fluctuated to an up-down direction, and the irradiation angle of irradiation light is adjusted. Further, the light receiving unit 13 is swung in the vertical direction to adjust the angle in the detection direction.
The control unit 19 continuously drives the first drive unit 16 and the second drive unit 17 based on the detection signal from the light receiving unit 13 and the detection signal from the vehicle attitude angle detection unit 18. Although the control is performed, the first drive unit 16 and the second drive unit 17 may be intermittently controlled every predetermined time in order to reduce the control burden.

The vehicle headlamp 10 according to the embodiment of the present invention is configured as described above, and light L1 is emitted from the light emitting portion of the bulb 11 when the bulb 11 is supplied with power from the outside.
The light L1 emitted from the bulb 11 is reflected directly or by the reflecting surface 12 to become substantially parallel light, and is further irradiated forward through the cover lens 15 in the light irradiation direction.

Here, during normal traveling, that is, when the light receiving unit 13 is traveling on a flat road at a horizontal vehicle attitude angle without detecting the light L2 from the preceding vehicle or the oncoming vehicle, the light receiving unit 13 and No detection signal is sent from the vehicle attitude angle detection means 18. For this reason, the control part 19 adjusts the irradiation angle of irradiation light to a substantially horizontal irradiation angle by driving-controlling the drive circuit 16b of the 1st drive means 16, and driving the actuator 16a. Further, the second driving means 17 is driven and controlled so that the detection direction of the light receiving unit 13 is adjusted to a substantially horizontal direction.
As a result, a normal light distribution pattern similar to that shown by the solid line in FIG. 3 is formed.

When light L2 from a preceding vehicle or an oncoming vehicle enters the light receiving unit 13, the light receiving element 13b of the light receiving unit 13 detects the light L2 and sends a detection signal to the control unit 19.
The control unit 19 drives and controls the drive circuit 16b of the first drive means 16 based on the detection signal from the light receiving unit 13 to drive the actuator 16a. Thereby, the upper end of the reflective surface 12 is moved and adjusted forward.
Therefore, the irradiation angle of the irradiation light irradiated from the bulb 11 directly or reflected by the reflecting surface 12 toward the front is moved slightly downward.
For this reason, since the light distribution pattern by irradiation light L1 can be displaced below, it does not give a dazzling light with respect to a preceding vehicle or an oncoming vehicle.

When the vehicle attitude angle changes due to road surface unevenness or inclination while the automobile is running, the vehicle attitude angle detection means 18 detects a change in the vehicle attitude angle and sends a detection signal to the control unit 19.
The control unit 19 drives and controls the drive circuit 16b of the first drive unit 16 and the drive circuit 17b of the second drive unit 17 based on the detection signal from the vehicle attitude angle detection unit 18, respectively. The actuator 16a and the actuator 17a are driven.
As a result, when the vehicle attitude angle changes due to unevenness or inclination of the road surface, the irradiation angle of the irradiation light L1 by the bulb 11 and the reflecting surface 12 and the detection direction of the light receiving unit 13 correspond to the change in the attitude angle. In other words, it is adjusted substantially in the horizontal direction toward the front.

In this case, the irradiation angle of the irradiation light is adjusted by the variation of the vehicle attitude angle. However, when there is a preceding vehicle or an oncoming vehicle, the control is performed based on the detection signal from the light receiving unit 13. The unit 19 drives and controls the drive circuit 16b of the first drive unit 16 so as to lower the irradiation angle of the irradiation light corresponding to the preceding vehicle or the oncoming vehicle in addition to the correction of the vehicle attitude angle. It will be.
Therefore, even when the vehicle attitude angle changes, the irradiation angle of the irradiation light L1 is always adjusted appropriately. As a result, no dazzling light is given to the preceding vehicle or the oncoming vehicle.

  In the above-described embodiment, the light receiving unit 13 detects the light L2 from both the preceding vehicle and the oncoming vehicle, but is not limited thereto, and selectively detects the light from the preceding vehicle. It is obvious that the light receiving unit and the light receiving unit that selectively detects light from the oncoming vehicle may be provided separately.

  In the above-described embodiment, the reflecting surface is configured as a parabolic reflecting surface and no projection lens is provided. However, the present invention is not limited to this, and the reflecting surface is configured as an elliptical reflecting surface. It is also possible to apply the present invention to a so-called projector type vehicle headlamp in which a light source image by a system reflection surface is irradiated forward by a projection lens.

Furthermore, in the above-described embodiment, the control unit 19 drives and controls the first drive unit 16 and the second drive unit 17 based on the detection signal from the vehicle attitude angle detection unit. Not limited to this, on the basis of vehicle information such as vehicle speed and steering angle, road information such as suburban roads and city roads, weather information, and the like, the first drive means 16 and the first By controlling the driving of the second driving means 17, the irradiation angle of the irradiation light may always be adjusted appropriately.
In this case, the first driving means 16 can also swing the bulb 11 and the reflecting surface 12 in the left-right direction as necessary.

  In the above-described embodiment, the vehicle headlamp 10 is configured as a headlamp of an automobile. However, the present invention is not limited thereto, and it is apparent that the present invention can be applied to an auxiliary headlamp such as a fog lamp. It is.

  Furthermore, in the above-described embodiment, the control unit 19 swings the irradiation angle of the irradiation light downward by a predetermined angle based on the detection signal from the light receiving unit 13. Not limited to this, the irradiation angle of the irradiation light can be changed continuously or stepwise according to the amount of light incident on the light receiving unit 13, that is, according to the approaching state of the preceding vehicle or the oncoming vehicle.

  Thus, according to the present invention, an extremely excellent vehicle headlamp can be provided in which the light receiving unit that detects light from the preceding vehicle or the oncoming vehicle is housed in the housing with a simple configuration. .

It is a schematic side view which shows the structure of one Embodiment of the vehicle headlamp by this invention. It is a schematic side view which shows the structure of an example of the conventional vehicle headlamp. It is a graph which shows the light distribution pattern by the vehicle headlamp of FIG.

Explanation of symbols

10 Vehicle headlights 11 Bulb (light source)
DESCRIPTION OF SYMBOLS 12 Reflecting surface 13 Light receiving unit 14 Case 14a Back surface 15 Cover lens 16 1st drive means 16a Actuator 16b Drive circuit 17 2nd drive means 17a Actuator 17b Drive circuit 18 Vehicle attitude angle detection means 19 Control part

Claims (7)

A light source;
In order to reflect the light from the light source toward the front in the light irradiation direction, a concave reflecting surface toward the front in the light irradiation direction;
First driving means for integrally swinging the light source and the reflecting surface in the vertical direction;
A liquid-tight enclosure surrounding the light source, the reflective surface and the first drive means, and a housing with an open front surface;
A cover lens closely attached to cover the front surface of the housing;
A control unit for driving and controlling the driving means disposed outside the housing;
A vehicle headlamp comprising:
A light receiving unit that is disposed behind an opening provided in a part of the reflecting surface and detects light from a preceding vehicle and / or an oncoming vehicle that enters through the opening from the front in the light irradiation direction;
Second driving means for swinging the light receiving unit in the vertical direction;
With
The control unit drives and controls the first driving unit based on the detection signal from the light receiving unit, and raises and lowers the irradiation angle of the irradiation light irradiated from the light source toward the front of the light irradiation direction through the reflection surface. A vehicle headlamp characterized in that a light distribution pattern is displaced downward by adjusting the direction. Furthermore, it is equipped with vehicle attitude angle detection means,
Based on the detection signal from the vehicle attitude angle detection means, the control unit drives and controls the second drive means to maintain the detection direction of the light receiving unit in the horizontal direction regardless of the attitude angle of the vehicle. The vehicle headlamp according to claim 1, wherein the vehicle headlamp is characterized.   The control unit drives and controls the first drive unit based on detection signals from the light receiving unit and the vehicle attitude angle detection unit, and adjusts the irradiation angle of the irradiation light with reference to the horizontal direction. The vehicle headlamp according to claim 2.   The said control part controls drive of a 1st drive means and / or a 2nd drive means for every predetermined time interval, or continuously, The said any one of Claim 1 to 3 characterized by the above-mentioned. Vehicle headlamps.   The control unit displaces the irradiation angle of the irradiation light continuously or stepwise by driving and controlling the first driving unit according to the light receiving intensity of the light receiving unit. Item 5. A vehicle headlamp according to any one of Items 1 to 4.   The vehicle headlamp according to any one of claims 1 to 5, wherein the control unit further controls driving of the first driving unit based on other vehicle information and surrounding information.   The vehicle headlamp according to any one of claims 1 to 6, wherein the light receiving unit is detachably and liquid-tightly attached to the housing.

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