JP2001268013A - Optical signal transmission equipment - Google Patents

Abstract

(57) Abstract: In an optical signal transmission device, the intensity of a direct optical signal propagating from a light emitting section to a light receiving section to the light receiving section and a reflected light signal propagating from the light emitting section to the light receiving section via the reflecting section. The optical signal transmission in the in-vehicle device is performed reliably and stably without reducing the difference from the incident intensity of the optical signal and taking special measures such as providing an amplifier circuit. A light emitting unit, a reflecting unit, and a light receiving unit with respect to an incident intensity of a first optical signal propagating along a first propagation path (A) connecting a light emitting unit (10) and a light receiving unit (5a) to the light receiving unit. The optical axis of the light emitting element (11) of the light emitting unit is moved along the first propagation path so that the ratio of the incident intensity of the second optical signal propagating along the second propagation path (B) connecting the first and second parts is equal to or greater than a predetermined value. To the second propagation path side, and even when the first optical signal is blocked by an obstacle, the second optical signal of a required level is made to enter the light receiving unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a seat unit,
The present invention relates to an optical signal transmission device for transmitting an optical signal used for drive control of an in-vehicle device such as an air conditioner and an audio device, and more particularly, to an optical signal transmission device capable of reliably and stably transmitting an optical signal.

[0002]

2. Related Background Art A vehicle is equipped with various devices for improving the comfort of a driver or an occupant, for example, a seat unit capable of adjusting the position and posture of a seat. A typical seat unit includes a seat adjuster that adjusts a seat height, a front-rear position, and a tilt angle of a backrest, and an operation unit including a manual switch that can be operated by a driver or an occupant. The seat adjuster has a plurality of movable parts respectively connected to the seat and the backrest, and a plurality of motors for driving the plurality of movable parts under the control of a control unit responsive to a manual switch operation. Generally, the control unit is also used for drive control of an in-vehicle device other than the seat unit.

[0003]

In this type of seat unit, an operating section, a motor, a control unit, and an operating power supply are usually connected to each other via a plurality of wire harnesses, and the wire harness is provided around an adjuster movable section. Distributed to. For this reason, when the adjuster movable part is driven, the wire harness is bitten by the adjuster movable part,
The seat adjuster may malfunction or the wire harness may be damaged.

In order to solve such a problem, attempts have been made to reduce the number and thickness of the wire harness in order to prevent interference between the wire harness and the movable adjuster. For example, an attempt has been made to use an optical signal transmission device that propagates an optical signal in free space from an operation unit to a control unit, instead of supplying an electric signal from the operation unit to the control unit via a wire harness. ing. For example, the optical signal transmission device includes a light emitting unit and a light receiving unit provided in the operation unit and the control unit, respectively, and is configured to receive the optical signal emitted from the light emitting unit in the light receiving unit.

In the above optical signal transmission device, if an obstacle is present on the optical signal propagation path extending between the light emitting section and the light receiving section, the transmission of the optical signal from the light emitting section to the light receiving section is impeded. . For example, in the case of an optical signal transmission device provided in a seat unit, when the adjuster movable section is driven, the adjuster movable section or the wire harness may be located on the propagation path and hinder optical signal transmission.

In connection with such a problem, see, for example,
Japanese Patent No. 40616 discloses that a part of an optical signal emitted from an optical transmitting unit is reflected by a reflecting unit provided at a location away from an obstacle, and a part of the reflected optical signal is incident on the optical receiving unit. An optical space transmission device having such a configuration is disclosed. Therefore, in order to eliminate the optical signal transmission failure due to the obstacle, a reflection unit is provided in the seat unit or in the vicinity thereof according to the teaching of the above-mentioned publication, and the obstacle is provided on the optical signal transmission path in the optical signal transmission device mounted on the seat unit. It is conceivable that optical signal transmission can be performed even in the presence of

[0007] However, the optical space transmission device described in the above publication is used for remote control of video equipment and the like in a house and for spatial transmission of audio signals. It is difficult to obtain an optical signal transmission apparatus that does not cause an optical signal transmission failure due to an obstacle simply by applying it to an optical signal transmission apparatus for a vehicle-mounted apparatus. Hereinafter, the reason will be described.

An optical signal transmission device for a seat unit to which the teaching of the above publication is applied includes, for example, a light emitting unit provided in an operation unit, a light receiving unit provided in a control unit, and an optical signal emitted from the light emitting unit. And a reflecting portion for reflecting the light toward the light receiving portion. The light emitting unit and the light receiving unit have directional characteristics. The optical signal emitted from the light emitting unit is composed of signal components emitted in various directions having different emission angles with respect to the optical axis of the light emitting unit. The emission intensity of the signal component is determined according to the directivity characteristic of the light emitting unit, that is, the emission angle-emission intensity characteristic. Hereinafter, an optical signal propagation path extending between the light emitting unit and the light receiving unit and an optical signal propagation path extending between the light emitting unit, the reflecting unit, and the light receiving unit are referred to as first and second propagation paths, respectively. The second propagation path includes an upstream path section connecting the light emitting section and the reflecting section and a downstream path section connecting the reflecting section and the light receiving section.

In such an optical signal transmission apparatus, even if an obstacle exists on the first propagation path, the optical signal transmission apparatus can transmit the optical signal along the second propagation path. It is necessary to determine the arrangement position of the reflector so that the side path section forms a sufficiently large angle with respect to the first propagation path.
On the other hand, the light emitting element and the light receiving element constituting the light emitting section and the light receiving section, respectively, have directional characteristics, and there are restrictions on the types of reflectors that can constitute the reflecting section in an in-vehicle device such as a seat unit. For this reason, the incident intensity of the optical signal propagating along the second propagation path (hereinafter, referred to as “second optical signal” or “reflected optical signal”) to the light receiving unit is equal to the first intensity.
When the incident intensity of the optical signal propagating along the propagation path (hereinafter, referred to as “first optical signal” or “direct optical signal”) is considerably lower and an obstacle exists on the first propagation path, Although the second optical signal is transmitted, an optical signal transmission failure may occur.

Hereinafter, the above situation will be described more specifically. The light emitting element and the light receiving element of the optical signal transmission device,
Typically, it has directivity characteristics as shown in FIGS. 11 and 12, respectively. Here, when the optical signal transmission device is configured such that the upstream and downstream path sections of the second propagation path make an angle of, for example, 30 degrees with respect to the first propagation path, the first signal at the time of emission from the light emitting element The relative intensity of the second optical signal with respect to the optical signal is 30 according to the directional characteristics of the light emitting element.
%, And if the first and second optical signals have the same intensity immediately before incidence on the light receiving element, the relative intensity of the second optical signal with respect to the first optical signal upon incidence on the light receiving element is 90% according to the directional characteristics of And Table 1
In the case where an iron seat cushion frame is used as the reflecting portion among the seat unit components listed in (1), the relative intensity (reflectance) of the second optical signal before and after reflection at the reflecting portion is 25%.

After all, in the optical signal transmission device having the above configuration, the relative intensity of the second optical signal with respect to the first optical signal when entering the light receiving element is represented by the product of the three relative intensities;
Therefore, it is about 7% (≒ 30% × 25% × 90%). As is clear from Table 1, when the reflectance of the seat cushion frame is 25%, which is the largest among the components of the seat unit with respect to the reflectivity, and when the other material of the seat unit constitutes the reflecting material, when the light enters the light receiving element. , The relative intensity of the reflected light signal with respect to the direct light signal is further reduced.

[0012]

[Table 1]

As described above, in an optical signal transmission device mounted on a vehicle-mounted device such as a seat unit, the incident intensity of a reflected light signal (second optical signal) is larger than that of a direct optical signal (first optical signal). If the optical signal is directly blocked by the obstacle, the reflected light signal is used for the transmission of the optical signal between the light emitting unit and the light receiving unit, but the optical signal transmission failure occurs. May be

Further, an amplification circuit is provided in the light receiving section to amplify the reflected light signal, or a light receiving element having a high sensitivity is provided in the light receiving section so that a low level reflected light signal can be received. By using the unit, it is possible to prevent an optical signal transmission failure due to a low signal level of the reflected optical signal, but the optical signal transmission device becomes costly or an in-vehicle device on which this transmission device is mounted. It needs to be modified.

[0015] It is an object of the present invention to provide an intensity of a direct optical signal propagating in a free space from a light emitting section to a light receiving section to the light receiving section and an incidence of a reflected light signal propagating from the light emitting section to the light receiving section via the reflecting section. An optical signal transmission device that can reliably and stably transmit an optical signal in an in-vehicle device such as a seat unit, an air conditioner, and an audio device without reducing the difference from the strength and taking special measures such as providing an amplifier circuit. To provide.

[0016]

In order to achieve the above object, a first propagation path extending from a light emitting section to a light receiving section for transmitting an optical signal provided in a vehicle and used for drive control of an in-vehicle device; 2. The optical signal transmission device according to claim 1, wherein the optical signal transmission device propagates in free space from a light emitting unit to a reflecting unit disposed outside the light emitting unit and the light receiving unit along a second propagation path extending to the light receiving unit. The invention is directed to a ratio of an incident intensity of the second optical signal propagating along the second propagation path to the light receiving section to an incident intensity of the first optical signal propagating along the first propagation path to the light receiving section. The optical axis of the light emitting element of the light emitting section or the light receiving element of the light receiving section is shifted so that the light emission amount of the light emitting element or the light receiving element of the light receiving section does not exceed a predetermined value that does not cause optical signal transmission failure.

According to the first aspect of the present invention, the optical axis of the light emitting element or the light receiving element is shifted from the first propagation path to the second propagation path, for example. Since the directivity that the light signal emission intensity becomes smaller as the angle between the optical axis of the element and the optical axis becomes larger is stronger than that of the light receiving element, compared with the case where the optical axis of the light emitting element matches the first propagation path, Is the first.
Small on the propagation path and large on the second propagation path,
Therefore, the second intensity with respect to the intensity of the first optical signal incident on the light receiving unit
The ratio of the incident intensity of the optical signal increases. The deviation of the optical axis of the light emitting element or the light receiving element from, for example, the first propagation path is set so that the ratio of the incident light intensity is equal to or more than a predetermined value, for example, 25% or more, and therefore, the first optical signal is blocked by, for example, an obstacle. Also in this case, the second optical signal of the required level does not enter the light receiving unit and does not cause optical signal transmission failure. Further, there is no need to configure the light emitting element or the light receiving element or both elements with high sensitivity, or to provide an amplifier circuit for amplifying the optical signal in the light receiving section, so that the cost of the optical signal transmission device can be reduced. In addition, the second optical signal of a required level can be obtained even when the reflecting section is formed of a component having a low reflectance. Therefore, the reflecting section can be formed by the components of the vehicle or the vehicle-mounted device. The cost of the device is reduced.

According to a second aspect of the present invention, at least one of the light emitting element of the light emitting section and the light receiving element of the light receiving section is installed upward. Dust easily accumulates in a vehicle in which an optical signal transmission device used for drive control of an in-vehicle device is installed, for example, on a vehicle body floor, and when dust adheres to a light emitting element or a light receiving element of the optical signal transmission device, light is emitted. There is a possibility that a signal transmission failure may occur. By arranging the light emitting element and the light receiving element apart from the vehicle body floor, for example, it is possible to reduce the adhesion of dust soaring from the vehicle body floor, but there are restrictions on the arrangement position of the optical signal transmission device. In the invention according to claim 2, at least one of the light-emitting element and the light-receiving element is installed upward, and when the optical signal transmission device is arranged close to the vehicle body floor, the dust soaring from the vehicle body floor and particularly large dust are emitted from the light-emitting element or Adhesion to the light receiving element or both of them becomes difficult, and optical signal transmission failure due to adhesion of dust is prevented.

According to a third aspect of the present invention, there is provided an optical signal transmission device disposed in a vehicle for transmitting an optical signal used for drive control of an in-vehicle device in a free space from a light emitting unit to a light receiving unit. The light emitting device further includes a reflector disposed outside the light emitting unit and the light receiving unit and having first and second inclined reflecting surfaces. The light is emitted from the light emitting unit, reflected by the first and second inclined reflecting surfaces, and incident on the light receiving unit. The light axis of the light-emitting element of the light-emitting unit and the light-receiving unit are received such that the ratio between the incident intensities of the first and second optical signals is not less than a predetermined value that does not cause optical signal transmission failure, for example, 25% or more. A virtual line connecting the first and second portions to the reflecting portion.

According to a third aspect of the present invention, the first and second optical signals from the light emitting element disposed with the optical axis deviated from the virtual line connecting the light emitting section and the light receiving section toward the reflecting section are formed on the reflecting section. The first and second inclined reflecting surfaces reflect the light toward the light receiving unit, and two light signal propagation paths are formed between the light emitting unit and the light receiving unit, so that the intensity of the light signal incident on the light receiving unit And the light signal transmission from the light emitting unit to the light receiving unit via the reflecting unit can be performed satisfactorily. Moreover, the light-emitting unit and the light-receiving unit can be arranged close to the reflection unit in the direction in which the optical signal transmission device is viewed from the installation surface of the optical signal transmission device, that is, separated from the installation surface of the optical signal transmission device. It is possible to prevent dust soaring from adhering to the light emitting unit and the light receiving unit, thereby preventing an optical signal transmission failure due to the adhesion of the dust.

According to a fourth aspect of the present invention, as in the second aspect of the present invention, at least one of the light emitting element of the light emitting section and the light receiving element of the light receiving section is installed upward. It is characterized by having done. In this case, optical signal transmission failure due to the attachment of dust to the light emitting element or the light receiving element is prevented. In the first and second aspects of the present invention, for example, the light emitting element can be arranged so that its optical axis coincides with the upstream path section extending from the light emitting section to the reflecting section in the second propagation path. In this case, the emission intensity of the second optical signal from the light emitting element becomes maximum, and the incident intensity of the second optical signal to the light receiving unit increases. According to the third and fourth aspects of the present invention, it is possible to increase the intensity of the reflected light signal by setting the optical axis of the light emitting element between the first and second inclined reflecting surfaces.

In the first and second aspects of the present invention, for example, when the optical signal transmission device is configured so that the angle formed by the first and second propagation paths is large, the light emitting section includes the first and second optical signals. May be provided, or both optical signals may be emitted from one light emitting element. When a plurality of light emitting elements are provided in the light emitting section, the optical axes of the plurality of light emitting elements as a whole may be shifted from the first propagation path to the second propagation path side, for example, for the first and second optical signals. It is assumed that the optical axis of the light emitting element matches the first and second propagation paths. In this case, it is easy to increase the angle formed by the first and second propagation paths. Further, the cost can be reduced by using a light-emitting element having a relatively low maximum light emission intensity, or, in the case of a light-emitting element having a relatively high maximum light emission intensity, the drive current of the light-emitting element is reduced to extend the life of the light-emitting element. can do.
On the other hand, when one light emitting element is provided in the light emitting unit, one or more reflectors are arranged in a path section extending in the light emitting unit in the first propagation path or a path section extending in the light emitting unit in the second propagation path. It is possible, so that the angle formed by the first and second propagation paths can be easily increased. There is little restriction on the constituent material of the reflector disposed in the light emitting unit, and it is possible to avoid the decrease in the emission intensity of the first or second optical signal by configuring the reflector with a constituent material having a high reflectance.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical signal transmission device according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a main part of a seat unit provided with an optical signal transmission device according to the present invention. In FIG. 1, the seat unit 1 includes a seat cushion frame 2 for supporting a seat (not shown) and a vehicle cushion. A seat adjuster 3 disposed below the seat cushion frame 2 on the floor mat 6 provided on the floor and supporting the frame 2; and a seat switch unit (hereinafter, referred to as "SW unit") 4 attached to a cushion shield (not shown). ,
A position control unit (hereinafter, referred to as “ECU”) 5 attached to the seat adjuster 3.

As shown in FIGS. 2 and 3, the optical signal transmission device includes a light emitting unit 10 mounted in the SW unit 4.
And a light receiving unit 5a mounted in the ECU 5. The light emitting unit 10 includes, for example, a light emitting element 11 that outputs an infrared light signal and a substrate 12, and the light emitting element 11 is provided on the substrate 12 according to a switch signal from a sheet switch (not shown) of the SW unit 4. A light emission control circuit for driving control is mounted. Housing 41 of SW unit 4
Is provided with a light-emitting window 42 made of glass, synthetic resin, or the like. Further, as shown in FIG. 1, a light-receiving window 52 made of glass, synthetic resin, or the like is attached to a housing 51 of the ECU 5.

In the optical signal transmission device basically configured as described above, the optical signal emitted from the light emitting element 11 of the SW unit 4 is a signal component emitted in various directions with respect to the optical axis of the light emitting element. Consists of The signal component passes through the light emission window 42 and propagates in the free space toward the ECU 5. Hereinafter, an optical signal propagation path extending between the light emitting element 11 and the light receiving element 5b is referred to as a first propagation path A, and the light emitting element 11
And specific part (reflecting part) 2 of seat cushion frame 2
a light signal propagation path extending between
Called propagation path B. A signal component propagating along the first propagation path A is referred to as a first optical signal or direct optical signal or direct light, and a signal component propagating along the second propagation path B is referred to as a second optical signal or reflection. It is called an optical signal or reflected light. The second propagation path includes an upstream path section connecting the light emitting element 11 and the reflection section, and a downstream path section connecting the reflection section and the light receiving element 5b. In the following description,
Symbols A and B may be attached to the first and second optical signals, respectively.

The first and second optical signals A and B are received by the light receiving element 5b of the ECU 5 through the light receiving window 52 of the ECU 5, and the ECU 5 operates the seat adjuster 3 according to the optical signal. Strictly, the second optical signal is delayed more than the first optical signal due to a path difference between the first and second propagation paths A and B, but the light emitting element and the light receiving element are compared with the propagation speed of the optical signal. This delay is negligible in optical signal transmission, since the distance between is very small.

In this embodiment, the SW unit 4 and the EC
U5b is arranged as shown in FIGS. That is, the distance between the light emitting element 11 of the SW unit 4 and the light receiving element 5b of the ECU 5 is 250 mm, the height difference between the light emitting element 11 and the seat cushion frame 2 is 60 mm, and the height difference between the light receiving element 5b and the seat cushion frame 2 is 70 mm.
mm, the light emitting element 11 and the light receiving element 5b
Is 10 mm.

The first angle formed by the first propagation path A and the upstream path section of the second propagation path B, and the first propagation path A and the second propagation path
The second angle formed by the downstream path section of the propagation path B is geometrically determined by the arrangement relationship between the light emitting element 11, the reflection section 2a, and the light receiving element 5b, and is the case of the arrangement examples of FIGS. The first and second angles are about 30 degrees and about 2 degrees, respectively.
5 degrees. In the present embodiment, the light emitting element 11 has the directional characteristics shown in FIG. 11, and is arranged such that its optical axis matches the upstream path section of the second propagation path B. That is, the first propagation path A forms an angle of 30 degrees with the optical axis of the light emitting element 11. The light receiving element 5b has the directional characteristics shown in FIG. 12, and is arranged such that its optical axis is located between the first propagation path A and the downstream path section of the second propagation path B.

In the above arrangement example, the emission intensity of each of the first and second optical signals A and B is equal to the maximum emission intensity of the light emitting element 11 (that is, the emission intensity in the optical axis direction).
３０30% and 100%. The reflectivity of the seat cushion frame 2 constituting the reflecting portion 2a is expressed as a function of the wavelength of the optical signal as shown by a solid line in FIG. 5, and the wavelength range of the optical signal used in the present embodiment is 850 to 950 nm.
Is about 25%. The reflectivity of the interior wall surface of the seat unit is about 10% as shown by a dashed line in FIG. Then, based on the directional characteristics and the orientation of the arrangement of the light receiving element 5b, the first and second optical signals A,
The input levels of B are substantially the same.

While a direct optical signal emitted from the light emitting element 11 at a low intensity is directly received by the light receiving element 5b,
Since the reflected light signal emitted with a high intensity is reflected by the reflecting unit, the incident intensities of the direct light signal and the reflected light signal to the respective light receiving elements are substantially equal to each other as shown in FIG. That is, in this embodiment, the ratio of the incident intensity of the reflected light signal to the incident intensity of the direct optical signal is approximately 100%. However, in the present invention, this ratio may be 25% or more in order to perform suitable optical signal transmission.

As described above, in the present embodiment, the light receiving element 5
b, the incident light intensity of the direct light A is substantially equal to the incident light intensity of the reflected light B. Therefore, even when the direct light A is blocked by the obstacle 7, the reflected light B having the same input level as the direct light A is obtained. The light enters the light receiving element 5b, and accordingly, an optical signal having an input level of about 1/2 of the normal input level enters the light receiving element 5b.
As a result, even when the light A is directly blocked by the movable portion of the sheet adjuster 3 or the wire harness that can move on the first optical signal propagation path of the optical signal transmission device, the optical signal transmission is reliably performed. Transmission reliability is improved.

As described above, in the present embodiment, the light receiving axis of the light receiving element 5b is directed to the middle between the direct light propagation path A and the reflected light propagation path B. Since the difference between the light receiving sensitivity and the reflected light receiving sensitivity is small, there is no need to provide an amplifier circuit in the light receiving section 5a or use a high-sensitivity light receiving element, thereby reducing the manufacturing cost. Also,
In the present embodiment, since the reflecting portion 2a can be constituted by the existing seat unit component and the seat cushion frame 2 having a relatively low reflectance, a reflecting portion having a high reflectance can be provided or the seat cushion frame 2 can be made of aluminum. There is no need to take special measures such as attaching a high-reflectance reflective material such as a vapor-deposited film, so that manufacturing costs can be reduced.

Further, in the present embodiment, when the SW unit 4 and the ECU 5 are arranged on the seat unit 2,
Since it is not necessary to make the optical axis of the light emitting element 11 of the W unit 4 coincide with the optical axis of the light receiving element 5b of the ECU 5, strict position tuning of the SW unit 4 and the ECU 5 becomes unnecessary, and the manufacturing cost can be reduced. Hereinafter, FIG.
An optical signal transmission device according to the second embodiment of the present invention will be described with reference to FIG.

In this embodiment, the distance between the light emitting element and the light receiving element is short, so that the first propagation path A and the second propagation path B
It is intended to perform suitable optical signal transmission even when the angle between them is considerably large. If the angle formed by the first and second propagation paths is appropriate, the light-emitting element is arranged so that its optical axis coincides with, for example, the second propagation path, as in the case of the first embodiment. The input levels of the direct optical signal and the reflected optical signal can be made appropriate. However, when the angle between the first and second propagation paths is large, the direct optical signal and the reflected It is difficult to simultaneously make the input levels of the signals to both light receiving units required.

In the optical signal transmission device according to the present embodiment, the first upstream path section of the first propagation path A extends at a relatively small angle with respect to the optical axis of the light emitting element so as to extend from the light emitting element.
The emission intensity of the optical signal is increased, and two reflectors are provided in a path section of the first propagation path A extending inside the light emitting section, so that a path section of the first propagation path A downstream of the light emitting section is provided. It extends at a large angle with respect to the second propagation path B. Further, the second propagation path B coincides with the optical axis of the light emitting element (more generally, extends at a relatively small angle with respect to the optical axis of the light emitting element). . That is, according to the apparatus of the present embodiment, the emission intensity of the first and second optical signals from the light emitting element is required even when the angle between the first and second propagation paths A and B is large. Can be.

Specifically, as shown in FIG. 7, the distance between the light emitting element 11 of the SW unit 4 and the light receiving element 5b of the ECU 5 is set to 60 mm, and the first propagation path A and the second propagation path The upstream path section of the path B forms an angle of about 75 degrees, and the first path A and the downstream path section of the second path B form an angle of about 57 degrees. The light emitting element 11 and the light receiving element 5b are arranged such that the optical axis matches the upstream path section and the downstream path section of the second propagation path B, respectively.
Then, as shown in FIG.
Are provided with windows 45 and 46, and two reflection plates 43 and 44 are provided in the SW unit 4. The reflection plates 43 and 44 are made of a member having a reflectance of, for example, 90%. The reflection plate 43 is arranged near the light emitting element 11,
The first optical signal emitted from the light emitting element 11 is reflected toward the reflection plate 44.

The first optical signal is 1 with respect to the optical axis of the light emitting element.
The light propagates along the most upstream path section of the first propagation path A extending at an angle of 0 degrees. The first reflected by the reflection plate 44
The optical signal is emitted to the free space through the window 45, and forms the first propagation path A at an angle of about 75 degrees with the second propagation path B.
The light propagates toward the light receiving element 5b along a path section downstream of the light emitting unit 10 of FIG.

On the other hand, the second optical signal emitted from the light emitting element 11 propagates in the free space through the window 46 toward, for example, a specific portion (reflecting portion 2a) of the seat cushion frame 2. As described above, the seat cushion frame 2 is made of iron, and has a reflectance of about 25% at a wavelength of 850 to 950 nm of an optical signal (see FIG. 5). The second optical signal reflected by the reflector propagates toward the light receiving element 5b.

The incident intensity of the second optical signal B on the light receiving element 5b is equal to a value obtained by multiplying the maximum light signal emission intensity of the light emitting element 11 by the reflectivity of the reflector 2a, and Of about 25%. On the other hand, the emission intensity of the first optical signal A emitted from the light emitting element 11 at an angle of 10 degrees with respect to its optical axis indicates the maximum optical signal output from the directivity characteristics of the light emitting element 11 shown in FIG. About 80% of the strength.
As described above, the first optical signal A has a reflectance of 90
% Reflecting plates 43 and 44, and then the light receiving element 5
The light enters the light receiving element at an angle of about 57 degrees with respect to the optical axis b. Considering the directional characteristics of the light receiving element 5b,
The input level of the first optical signal A to b is about 40% of the maximum optical signal input intensity of the light receiving element. Therefore, the light receiving element 5b
The incident intensity of the first optical signal A to the first optical signal A is obtained by multiplying the emission intensity of the first optical signal A by the reflectance of the reflector 43, the reflectance of the reflectance 44, and the input level of the first optical signal to the light receiving element 5b. This value is equal to about 25% of the maximum light signal emission intensity of the light emitting element 11.

As is apparent from the above description, in the optical signal transmission device of the present embodiment, both the incident intensities of the first and second optical signals A and B to the light receiving element 5b are equal to the maximum optical signal emission of the light emitting element 11. This is about 25% of the intensity, and the incident intensities of the first and second optical signals A and B are substantially equal to each other. Therefore, the first
As in the case of the embodiment, even when the direct light A is blocked by the obstacle 7, an optical signal having an input level of about 1/2 of the normal input level enters the light receiving element 5b, and the optical signal transmission is performed. It is done reliably.

In addition to this, the optical transmission device of the present embodiment arranges the reflectors 43 and 44 in the upstream path section of the first propagation path A of the optical signal, so that the first light emitted from the light emitting element 11 is emitted. And the angle between the first and second propagation paths A and B is increased and the distance between the light emitting element and the light receiving element is small. Obstacle 7 entering on one propagation path A
The optical signal transmission can be performed by avoiding this. Further, it is easy to form the reflection plates 43 and 44 having a high reflectance, and for example, an aluminum film may be attached to the surface of an iron plate.

Incidentally, strictly speaking, the first and second optical signals A, B
The second optical signal has a delay with respect to the first optical signal due to an optical path difference therebetween. However, since the distance between the light emitting element and the light receiving element is extremely short compared to the speed of light, this delay can be ignored in optical signal transmission. . In the case where the optical signal transmission device is configured such that the emission intensity difference between the first and second optical signals is suppressed and the angle formed by the first and second propagation paths A and B is a large value, for example, about 75 degrees. Instead of the device configuration of the second embodiment,
A plurality, for example, 2 emitting the first and second optical signals, respectively.
One light emitting element may be provided in the light emitting unit 10. in this case,
For example, the optical axes of the light emitting elements for the first and second optical signals are set to the first axis.
And the second propagation path. As is clear from the description of the device of the second embodiment,
The light emitting element for the second optical signal may have an emission intensity of about 40% of the emission intensity of the light emitting element common to the second embodiment that emits both the first and second optical signals. Can be reduced in size and production cost can be reduced. If the light emitting element for the second optical signal is of the same type as the common light emitting element, the operating current of the light emitting element for the second optical signal can be set to about 40% of that of the common light emitting element. it can.

Hereinafter, an optical signal transmission device according to a third embodiment of the present invention will be described with reference to FIG. The device of the present embodiment is intended to prevent optical signal transmission failure due to dust adhesion. An optical signal transmission device for an in-vehicle device, for example, for a seat unit is disposed below a seat on a floor mat disposed on a floor of a vehicle, for example. In this case, dust rises from the floor mat as the occupant gets on and off the vehicle and adheres to the light-emitting unit and the light-receiving unit. May cause problems. As a countermeasure, it is conceivable to arrange an optical signal transmission device at a position distant from the floor mat to avoid the attachment of dust, especially large particles that easily hinder optical signal transmission. There are restrictions on the arrangement position of the optical signal transmission device, and it is difficult to take such measures.

Therefore, in the present embodiment, as shown in FIG. 9, the light emitting element 11 of the light emitting section and the light receiving element 21 of the light receiving section are installed upward (toward the seat cushion frame) to prevent dust rising from the floor mat 6. It prevents adhesion. The basic configuration of the apparatus of the present embodiment is the same as that of the first embodiment, and the outline of the present apparatus will be described below.

The light emitting element 11 is installed so that its optical axis coincides with the upstream path section of the second propagation path B of the optical signal.
The light receiving element 21 is installed such that its optical axis is directed between the first propagation path A and the downstream path section of the second propagation path B. The distance between the light emitting element 11 and the light receiving element 21 is 30
0 mm, and the distance between the seat cushion frame 2 and the light emitting element 11 and the distance between the frame 2 and the light receiving element 21 are each set to 50 mm. Therefore, the first propagation path A and the second propagation path B of the optical signal. Has an angle of about 18 degrees, and the downstream path section of the first transmission path A and the second transmission path B has an angle of about 18 degrees.

The light emitting element 11 has the directional characteristics shown in FIG. 11, and is emitted from the light emitting element 11 in the direction of the upstream path section of the second propagation path B that is arranged so as to match the optical axis of the light emitting element 11. The emission intensity of the second optical signal is equal to 100% of the maximum optical signal emission intensity of the light emitting element. The second optical signal B is reflected by the seat cushion frame 2 having a reflectance of about 25% and functions as the reflecting portion 2a, and enters the light receiving element 21. Therefore, the incident intensity of the second optical signal (reflected light) B on the light receiving element 21 is about 25% of the maximum optical signal emission intensity of the light emitting element 11.

On the other hand, about 18 to the optical axis of the light emitting element 11
The emission intensity of the first optical signal emitted from the light emitting element 11 in the direction of the first propagation path A at an angle of degrees is about 50% of the maximum optical signal emission intensity of the light emitting element. The first optical signal propagates in free space from the light emitting element 11 to the light receiving element 21 and enters the light receiving element 21. The incident intensity of the first optical signal (direct light) A to the light receiving element 21 Is about 50%.

As described above, in the present embodiment, the light receiving element 21
The incident intensity of the reflected light B to the direct light A is about 1 /
2, even when the direct light A is interrupted by the obstacle 7, an optical signal having an input level of about 1/3 of the normal input level is incident on the light receiving element 21, thereby preventing optical signal transmission failure. You. As described above, according to the present embodiment, the same effect as that of the first embodiment can be obtained, and by attaching the light emitting element and the light receiving element upward, adhesion of dust soaring from the floor mat 6 is prevented. be able to.

Hereinafter, an optical signal transmission device according to a fourth embodiment of the present invention will be described. The optical signal transmission device of the present embodiment includes:
Even when the light emitting unit and the light receiving unit are arranged close to the reflecting unit, good optical signal transmission is performed, and it is intended to prevent dust from adhering to the light emitting unit and the light receiving unit. In the case of an optical signal transmission device for a seat unit, most of the dust adhering to the light emitting portion and the light receiving portion is dust soaring from the floor mat 6, and the adhesion of dust having large particles is a main factor for inhibiting optical signal transmission. Therefore, in the present embodiment, the reflecting portion is constituted by a part of the seat cushion frame 2 remote from the floor mat 6 and the seat cushion frame 2
The light-emitting unit and the light-receiving unit are installed in close proximity to the device to prevent the attachment of dust having large particles. However, when the light emitting section and the light receiving section are arranged close to the seat cushion frame 2, generally, a direct optical signal propagation path connecting the light emitting section and the light receiving section, and a reflected light signal propagation path connecting the light emitting section, the reflecting section, and the light receiving section. Since the angle formed by the path becomes too small, it becomes difficult to propagate the reflected light signal from the light emitting unit to the light receiving unit by bypassing the obstacle on the direct optical signal propagation path. In this regard, the device according to the present embodiment has a structure that extends between the light emitting unit, the reflecting unit, and the light receiving unit.
Two paths are provided near the seat cushion frame 2, and an optical signal is propagated along these paths regardless of the presence or absence of an obstacle.

More specifically, as shown in FIG. 10, the light emitting element 11 and the light receiving element 21 are connected to the seat cushion frame 2.
, So that the two elements 11 and 21 are separated from the floor mat 6. Light emitting element 11
Is 11m vertically from the seat cushion frame 2.
m away from each other, and its optical axis C is
It is disposed obliquely upward at an angle of 50 degrees with respect to a virtual line A connecting the light receiving element 21 and the light receiving element 21. The light emitting element 11 has the directional characteristics shown in FIG. 11, and the light signal emission intensity from the light emitting element 11 in the direction of the virtual line A is approximately 0% of the maximum light signal emission intensity of the light emitting element. That is, the optical signal emitted in the direction of the imaginary line A does not contribute to the optical signal transmission. The light receiving element 21
About 10mm vertically from the seat cushion frame 2
It is installed at a remote location.

Light emitting element 1 of seat cushion frame 2
1 is a reflecting portion 2a that exhibits a reflectance of about 25% for an optical signal having a wavelength of 850 to 950 nm.
Function as And the seat cushion frame 2
Are formed with two inclined reflecting surfaces 24 and 25. The reflection surface 24 is a virtual line (hereinafter, referred to as a first line) extending from the light emitting element 11 at an angle of 60 degrees with respect to the virtual line A.
(Referred to as the upstream path section of the propagation path B1) intersects with the upstream path section of the first propagation path B1 so as to reflect the optical signal from the light emitting element 11 toward the light receiving element 21. It extends diagonally. The reflection surface 25 is a virtual line (hereinafter, referred to as a second line) extending from the light emitting element 11 at an angle of 40 degrees with respect to the virtual line A.
(Referred to as the upstream path section of the propagation path B2) intersects with the upstream path section of the second propagation path B2 so as to reflect the optical signal from the light emitting element toward the light receiving element 21. It extends diagonally. Hereinafter, optical signals propagating in the free space from the light emitting element 11 to the light receiving element 21 along the first and second propagation paths B1 and B2 are respectively referred to as first and second optical signals (or first and second reflected optical signals). ).

As is apparent from the above description, the upstream path section of the first and second propagation paths B1 and B2 is the light emitting element 1
Makes an angle of 10 degrees with one optical axis,
From the directional characteristics of the light emitting element 11 in FIG.
The emission intensities of the first and second optical signals emitted from the light emitting element 1 in the first and second propagation path directions are about 80% of the maximum optical signal emission intensity of the light emitting element 11. The first and second optical signals are respectively reflected by the reflecting surfaces 24 and 25 having a reflectance of about 25%, and then enter the light receiving element 21. The light receiving element 21 is disposed so that its optical axis faces the middle of the respective downstream path sections of the first and second propagation paths B1 and B2.
The input levels of the first and second optical signals are substantially the same as the maximum optical signal input level of the light receiving element 21.

As described above, the optical signal transmission device of the present embodiment performs optical signal transmission based on the first and second optical signals regardless of the presence or absence of an obstacle. The first and second optical signals are not blocked even when the obstacle 7 takes a position close to the seat cushion frame 2 as illustrated in FIG. Although depending on the type of the light receiving element, the light signal incident level on the light receiving element 21 is about 20% of the maximum incident intensity.
%, There is no possibility of causing optical signal transmission failure. Therefore, according to the apparatus of the present embodiment, optical signal transmission failure can be prevented.

Further, in this embodiment, since the light emitting element 11 and the light receiving element 21 are installed at positions separated from the floor mat 6, dust soared from the floor mat 6, particularly dust having large particles, adheres to both elements. There is little fear. In particular, the light emitting element 11 is installed obliquely upward, and there is little possibility that dust adheres to the light emitting element 11. The optical signal transmission device of the fourth embodiment can be variously modified. For example, in the fourth embodiment, two reflecting surfaces are provided in the reflecting portion formed of the seat cushion frame to form two optical signal propagation paths. However, one or three or more reflecting surfaces are formed in the reflecting portion. One or three or more optical signal propagation paths may be formed. In this case, in order to prevent optical signal transmission failure, the optical signal incident intensity on the light receiving element is about 2 times of the maximum incident intensity.
It is assumed that the optical signal transmission device is configured to be 0% or more. For this reason, for example, a reflective material having a high reflectance may be attached to the reflective surface.

Hereinafter, an optical signal transmission device according to a fifth embodiment of the present invention will be described with reference to FIGS. The basic configuration of the device of this embodiment is substantially the same as that of the first embodiment. As shown in FIG. 13 to FIG.
1 is mounted vertically on the board 12 in the SW unit 4, and the light receiving element 21 is mounted vertically on the board 12 of the ECU 5. The light emitting element 11 and the light receiving element 21 are spaced apart from each other by 70 mm in the vehicle front-rear direction and 240 mm in the vehicle width direction.
It is 50 mm. As shown in FIG. 17, the height direction distance between the light emitting element 11 and the seat cushion frame 2 and the height direction distance between the light receiving element 21 and the seat cushion frame 2 are each set to 60 mm.
1 and a first optical signal propagation path A extending between
And the upstream path section of the second propagation path B extending between the light emitting element 11 and the specific portion (reflecting portion 2a) of the seat cushion frame 2 forms an angle of about 26 degrees, and the first propagation path A And the downstream path section of the second propagation path B forms an angle of about 26 degrees. The light emitting element 11 is, for example, 10 to 20 in the vehicle height direction relative to the light receiving element 21.
Although it is arranged at a position lower by mm, in the following description, it is assumed that both elements are installed at substantially the same position in the vehicle height direction.

The optical axis of the light emitting element 11 is directed to the middle between the first propagation path A and the upstream path section of the second propagation path B, and forms an angle of about 16 degrees with the first propagation path A. It forms an angle of about 10 degrees with the upstream path section of the second propagation path B. The optical axis of the light receiving element 21 is the first propagation path A
And a downstream path section of the second propagation path B and an angle of about 13 degrees with the downstream path sections of the first propagation path A and the second propagation path B. And the light emitting element 1
1 and the light receiving element 21 have the directional characteristics shown in FIGS.

In the above configuration, the emission intensity of the first optical signal (direct light) emitted from the light emitting element 11 in the first propagation path direction at an angle of about 16 degrees with the optical axis of the light emitting element 11
About 70% of the maximum light signal emission intensity of the light receiving element 21
The incident level of the first optical signal that is incident from a direction forming an angle of about 16 degrees with respect to is approximately 95% of the maximum optical signal input level of the light receiving element. Therefore, the incident intensity of the first optical signal to the light receiving element is about 66% of the maximum optical signal emission intensity of the light emitting element 11.
become. On the other hand, the emission intensity of the second optical signal (reflected light) emitted from the light emitting element 11 in the direction of the upstream path section of the second propagation path that forms an angle of about 30 degrees with the optical axis of the light emitting element 1
1 is about 25% of the maximum light signal emission intensity. The second optical signal is reflected by the reflecting portion 2a composed of the seat cushion frame 2 to which an aluminum film having a reflectivity of 75% is attached, and enters the light receiving element 21 from a direction forming an angle of about 30 degrees. Accordingly, the incident intensity of the second optical signal to the light receiving element is about 17% of the maximum optical signal emission intensity of the light emitting element 11, and the incident intensity of the first optical signal to the light receiving element is about 2%.
5%. As a result, even when the first optical signal (direct light) is blocked by an obstacle, both of the first and second optical signals are about 20% of the normal optical signal input level input to the light receiving element 21.
% Of the second optical signal is input to the light receiving element 21, and optical signal transmission failure is prevented.

The optical signal transmission device of the present embodiment can be modified in various ways. For example, without providing a high-reflectance reflection portion on the seat cushion frame 2, a reflectance of about 25 as in the first embodiment. The specific portion of the% seat cushion frame itself may be used as the reflection portion. In this case, in addition to such a reflecting portion, for example, one or more inclined reflecting surfaces are formed on the seat cushion frame 2 as in the case of the fourth embodiment, thereby providing a total of two or more reflecting portions. It is desirable that two or more reflected light signals be made incident on the light receiving element 21 so as to reliably prevent optical signal transmission failure when directly interrupting the optical signal.

According to the present embodiment, the same effects as in the first embodiment can be obtained, and the light emitting element and the light receiving element can be mounted perpendicular to the substrate surface. Becomes unnecessary, and the manufacturing cost can be reduced. Hereinafter, an optical signal transmission device according to a sixth embodiment of the present invention will be described with reference to FIGS.

The optical signal transmission device according to the present embodiment is used for optical signal transmission between a center cluster mounted on a vehicle and an air conditioner unit. 18 to 2
As shown in FIG. 0, the center cluster 61 includes a number of switches for driving and controlling an air conditioner unit 62 and an audio device (not shown) and a light receiving / emitting unit 61a, and is fixed to an instrument panel (not shown). . The air conditioner unit 62 includes an air conditioner controller, a blower motor (both not shown), and a light emitting / receiving unit 63, and is fixed to a body in the instrument panel.

The optical signal transmission device of this embodiment comprises a light receiving / emitting unit 61a in the center cluster 61 and a light receiving / emitting unit 63 in the air conditioner unit 62. Each light receiving / emitting unit includes a light emitting unit and a light receiving unit. The light emitting unit includes, for example, a substrate on which a light emitting element that outputs an infrared light signal and a light emitting control unit that drives and controls the light emitting element are mounted. Includes a light receiving element for receiving an optical signal from the light emitting element. Various optical signals are transmitted and received between the light receiving / emitting units 61a and 63. For example, an optical signal for controlling an air conditioner is transmitted from the light receiving / emitting unit 61a of the center cluster 61 to the light receiving / emitting unit 63 of the air conditioner unit 62. An optical signal for lighting the indicator is transmitted from the unit 63 to the light receiving / emitting unit 61a. A window member such as glass or synthetic resin is attached to each of the housings of the center cluster 61 and the air conditioner unit 62 so that an optical signal passes through the window member. And FIG.
As shown in FIG. 5, a reinforce 64 extends between the center cluster 61 and the air conditioner unit 62, and a specific portion of the reinforce 64 constitutes a reflection portion 64a. The reinforce 64 is made of iron and has a reflectance of 65% as shown in Table 2 below. FIG. 19 and FIG.
0, a symbol A indicates a first optical signal propagation path extending between the light emitting / receiving unit 61a of the center cluster 61 and the light emitting / receiving unit 63 of the air conditioner unit 62, and a symbol B indicates a light emitting / receiving unit 61a and a reflecting portion 64a. And light emitting and receiving unit 6
3 shows a second optical signal propagation path extending between the first optical signal propagation path and the third optical signal propagation path. As shown in FIG. 20, the distance between the two light receiving / emitting units 61a and 63 is 300 mm, and the reinforcement 64 is vertically separated from the first propagation path A by 22 mm. In this arrangement, the center cluster side path section and the air conditioner unit side path section of the second propagation path B form an angle of about 8 degrees with the first propagation path A. The light emitting element and the light receiving element of each of the light receiving and emitting units 61a and 63 are arranged, for example, with their respective optical axes directed to the middle between the first propagation path A and the second propagation path B. , B at an angle of about 4 degrees. 18 and 19
Reference numerals 61b and 61c denote a light emitting element and a light receiving element of the light receiving and emitting unit 61a, respectively.
63b indicates a light emitting element and a light receiving element of the light receiving and emitting unit 63, respectively.

Emission of the first and second optical signals emitted from the light emitting elements of each of the light receiving and emitting units 61a and 63 in the directions of the first and second propagation paths each forming an angle of about 4 degrees with respect to the optical axis thereof. Both the intensities are about 95% or more of the maximum light signal emission intensity of the light emitting element, and the input levels of the first and second optical signals respectively incident on the light receiving element at an angle of about 4 degrees are both of the light receiving element. It is about 95% or more of the maximum optical signal input level. Further, as described above, the reflectance of the reflecting portion is 65.
%.

Therefore, the input intensity of the first optical signal propagating along the first propagation path A between the light receiving / emitting units 61a and 63 to the light receiving element is approximately 90% of the maximum optical signal emission intensity of the light emitting element.
%, While the input intensity of the second optical signal propagating along the second propagation path B to the light receiving element is about 58% or more of the maximum signal emission intensity of the light emitting element. As a result, even when the first optical signal (direct light) is blocked by an obstacle, both the first and second optical signals have a level of about 39% or more of the normal optical signal input level input to the light receiving element. Second optical signal (reflected light)
Is input to the light receiving element, and optical signal transmission failure is prevented.

The present invention is not limited to the first to sixth embodiments, and can be variously modified without departing from the gist of the present invention. For example, the number of reflected light signal propagation paths is not limited to one, and a plurality of reflected light signal propagation paths may be provided. In this case, for example, a plurality of specific portions of the seat cushion frame are used as reflecting portions, and if necessary, inclined reflecting surfaces are formed on these reflecting portions as in the case of the fourth embodiment.

Further, in the present invention, instead of forming the reflecting portion with an iron seat cushion frame, the reflecting portion may be formed of, for example, aluminum or alumina.
Alternatively, these reflecting portion constituting materials may be attached to a seat cushion frame to form a reflecting portion. Table 2 shows typical reflecting portion constituting materials.

[0066]

[Table 2]

As described above, since the reflectance is higher when aluminum or alumina is used, even if the optical signal is directly interrupted by an obstacle, the incident intensity of the reflected optical signal to the light receiving portion increases, and Signal transmission failure can be more reliably prevented, and reliability is improved.

[0068]

As described above, according to the first aspect of the present invention, the intensity of the first optical signal propagating along the first propagation path extending between the light emitting section and the light receiving section to the light receiving section is reduced.
The light-emitting element of the light-emitting unit or the light-receiving element of the light-receiving unit is configured such that the ratio of the incident intensity of the second optical signal propagating along the second propagation path extending between the light-emitting unit, the reflection unit, and the light-receiving unit is equal to or greater than a predetermined value. Since the optical axis of the element is shifted, even when the first optical signal is interrupted by an obstacle, the second optical signal of a required level is incident on the light receiving unit and does not cause optical signal transmission failure. . Also, it is not necessary to configure the light emitting element or the light receiving element with a high sensitivity, or to provide an amplification circuit for amplifying the optical signal in the light receiving section, and further, the reflecting section can be configured by a component member of the vehicle or the vehicle-mounted device, The cost of the optical signal transmission device can be reduced.

According to the third aspect of the present invention, the ratio of the incident intensity of the first and second optical signals emitted from the light emitting portion, reflected by the first and second inclined reflecting surfaces of the reflecting portion, and incident on the light receiving portion is a predetermined value. As described above, since the optical axis of the light emitting element of the light emitting unit is shifted from the virtual line connecting the light emitting unit and the light receiving unit to the reflecting unit side, the optical signal transmission from the light emitting unit to the light receiving unit using the reflecting unit is performed. The light-emitting unit and the light-receiving unit can be placed away from the installation surface of the optical signal transmission device, preventing poor optical signal transmission caused by the dust flying from the installation surface adhering to the light-emitting unit or the light-receiving unit. it can.

According to the second and fourth aspects of the present invention, at least one of the light emitting element of the light emitting section and the light receiving element of the light receiving section is installed upward, so that the optical signal transmission failure caused by the adhesion of dust to the light emitting element or the light receiving element. Can be prevented.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a main part of a seat unit in which an optical signal transmission device according to the present invention is installed.

FIG. 2 is a schematic diagram illustrating a light emitting unit of the optical signal transmission device according to the first embodiment of the present invention.

FIG. 3 is a schematic side view showing an arrangement of a seat switch unit and a position control unit in the first embodiment.

FIG. 4 is a schematic diagram illustrating an arrangement relationship among a light emitting element, a light receiving element, and a reflection unit illustrated in FIG. 3;

FIG. 5 is a diagram showing light reflectance of a seat cushion frame and an interior wall surface as a function of wavelength.

FIG. 6 is a diagram showing a change with time of incident intensity of a direct optical signal and a reflected optical signal to a light receiving element.

FIG. 7 is a schematic diagram illustrating an arrangement relationship among a light emitting element, a light receiving element, and a reflection unit in an optical signal transmission device according to a second embodiment of the present invention.

FIG. 8 is a schematic diagram showing a light emitting unit shown in FIG. 7;

FIG. 9 is a schematic diagram illustrating an arrangement relationship among a light emitting element, a light receiving element, and a reflection unit in an optical signal transmission device according to a third embodiment of the present invention.

FIG. 10 is a schematic diagram illustrating an arrangement relationship among a light emitting element, a light receiving element, and a reflection unit in an optical signal transmission device according to a fourth embodiment of the present invention.

FIG. 11 is a diagram illustrating directivity characteristics of a typical light emitting element.

FIG. 12 is a diagram showing the directional characteristics of a typical light receiving element.

FIG. 13 is a schematic plan view showing an arrangement relationship between a sheet switch unit and a position control unit in an optical signal transmission device according to a fifth embodiment of the present invention.

FIG. 14 is a partial schematic view showing a substrate of the sheet switch unit shown in FIG. 13 and a light emitting element mounted thereon.

FIG. 15 is a schematic plan view showing a substrate of the position control unit shown in FIG. 13 and a light receiving element mounted thereon.

FIG. 16 is a schematic side view showing the substrate and the light receiving element shown in FIG.

FIG. 17 is a schematic diagram illustrating an arrangement relationship among a light emitting element, a light receiving element, and a reflecting portion in the device according to the fifth embodiment.

FIG. 18 is a schematic perspective view showing a center cluster and an air conditioner unit on which an optical signal transmission device according to a sixth embodiment of the present invention is mounted.

FIG. 19 is a schematic diagram illustrating an arrangement relationship between a light emitting element, a light receiving element, and a reflection unit in the optical signal transmission device according to the sixth embodiment.

20 is a schematic diagram illustrating an arrangement relationship between a light emitting element, a light receiving element, and a reflection unit illustrated in FIG. 19;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seat unit 2 Seat cushion frame 2a Reflection part 3 Seat adjuster 4 Seat switch unit (SW unit) 5 Position control unit (ECU) 5a Light receiving part 5b Light receiving element 6 Floor mat 7 Obstacle 10 Light emitting part 11 Light emitting element 12 Substrate 21 Light receiving Element 24, 25 Reflecting surface 41, 51 Case 42, 45, 46 Light emitting window 43, 44 Reflector 52 Light receiving window 61 Center cluster 62 Air conditioner unit 63 Light receiving element 64 Reinforce 64a Reflecting portion

Continued on the front page (72) Inventor Shigeki Motomura 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Inventor Takayuki Matsuoka 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric (72) Inventor Eiji Ichii 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (4)

[Claims] An optical signal provided in a vehicle and provided for drive control of an in-vehicle device, a first propagation path extending from a light emitting unit to a light receiving unit, and a first propagation path from the light emitting unit to the light emitting unit and the light receiving unit. An optical signal transmission device that propagates in free space along a second propagation path extending to the light receiving unit to a reflection unit disposed outside, wherein the light receiving of the first optical signal propagating along the first propagation path The ratio of the incident intensity to the light receiving unit of the second optical signal propagating along the second propagation path to the incident intensity to the unit is not less than a predetermined value so as not to cause optical signal transmission failure,
An optical signal transmission device, wherein an optical axis of a light emitting element of the light emitting unit or a light receiving element of the light receiving unit is shifted. 2. The optical signal transmission device according to claim 1, wherein at least one of the light emitting element of the light emitting unit and the light receiving element of the light receiving unit is installed upward. 3. An optical signal transmission device disposed in a vehicle for transmitting an optical signal used for drive control of an in-vehicle device in a free space from a light emitting unit to a light receiving unit, wherein the light emitting unit and the light receiving unit And a reflecting portion having a first and a second inclined reflecting surface formed outside the light emitting portion, wherein the light emitted from the light emitting portion is reflected by the first and second inclined reflecting surfaces and enters the light receiving portion. The optical axis of the light emitting element of the light emitting unit is set to the light emitting unit and the light receiving unit so that the ratio of the incident intensity of the first and second optical signals is equal to or greater than a predetermined value that does not cause optical signal transmission failure. An optical signal transmission device, wherein the optical signal transmission device is shifted from a connecting virtual line toward the reflection unit. 4. The light receiving section includes a light receiving element for receiving the first and second optical signals, and at least one of the light emitting element of the light emitting section and the light receiving element of the light receiving section is installed upward. The optical signal transmission device according to claim 3, wherein: