GB2364677A

GB2364677A - Optical switch in a vehicle

Info

Publication number: GB2364677A
Application number: GB0017235A
Authority: GB
Inventors: Gurbinder Singh Kalsi; David Barry
Original assignee: Meritor Light Vehicle Systems UK Ltd
Current assignee: ArvinMeritor Light Vehicle Systems UK Ltd
Priority date: 2000-07-14
Filing date: 2000-07-14
Publication date: 2002-02-06
Also published as: GB0017235D0

Abstract

A vehicle includes a switch comprising a light emitter E1 and a light detector D1. The switch may be associated with a movable component of a door latch. Either one part of the switch moves relative to the other or a part 30 of the latch 30 (e.g. a claw) provided with apertures 32 moves between the emitter E1 and detector D1 to signal the condition of the door lock. A further emitter and detector E2 and D2 can be used to provide more information regarding the condition of the door latch, e.g. whether in a closed, open or safety position.

Description

<Desc/Clms Page number 1> Vehicle The present invention relates to vehicles, and in particular road vehicles such as cars.

Known vehicles use electrical switches to provide various functions within the vehicle. In particular electrical switches are used within door latches and locking actuators to provide information about their mechanical state e.g. locked, unlocked, door ajar etc. Similarly Hall Effect Sensors are used in anti-squeeze controllers i.e. controllers that prevent body parts of people being trapped by a closing window glass, to determine the position of the window glass.

Microswitches suffer problems with mechanical tolerances and corrosion of electrical connections in the presence of moisture. Furthermore when the vehicle is parked, the microswitches have to be in an open condition so that the vehicle battery is not drained.

Hall Effect Sensors have mechanical tolerance and corrosion problems and also need current from the vehicle battery supply to function.

Advanced door latches use up to six switches and thus size and cost are becoming significant issues.

An object of the present invention is to provide a cheaper form of switch. A further object of the present invention is to provide a smaller form of switch. A further object of the present invention is to provide a more reliable form of switch. A further object of the present invention is to provide switch which uses less current.

Thus according to the present invention there is provided a vehicle including a switch in the form of alight emitter and a light detector, in use, light being transmitted by the light emitter and being received by the light detector to provide for a first switched state and the light not been received by the detector to provide for a second switched state.

G The light emitter may emit light when the vehicle is parked.

In one form the second switched state is provided for by moving the light transmitter relative to the light detector. In a further form the second switch state may be provided for by interrupting the light path between the light transmitter and the light detector.

In one form the light emitter may be an a laser, in particular a vertical cavity surface emitting semi conductor laser (VCSEL). The VCSEL may be operate in the infrared region. Furthermore infrared photodiodes and infra red phototransistors may be used within the switch.

The switch may be used to detect the position of door components such as the position of door latch components and/or the position of door window glass.

Two switches may be used in conjunction to provide for detecting each of at least three states of an associated component such as a door latch. The states may be superlocked, locked and unlocked.

Three switches may be used in conjunction to provide for detecting each of at least four states of an associated component such as a door latch. The states may be selected from door ajar, superlocked, locked with child safety on, locked with child safety off, unlocked with child safety on, unlocked with child safety off. Preferably under normal use a11 switches do not simultaneously achieve the first state and/or all switches do not simultaneously achieve second state.

Two switches may be comprise one light transmitter and two light detectors or one light detector and two light transmitters.

Three switches may comprise one light transmitter and three light detectors or one light detector and three light transmitters.

The invention will now be described-by way of example only, with reference to the accompanying drawings in which:- Figure 1 is a vehicle according to the present invention; Figure 2 and 3 are schematic representations of a first and second switch for use in the vehicle of figure 1; Figure 4 is a schematic representation of two switches for use in the vehicle of figure 1 and Figures 5 and 6 are embodiments of sets of three switches for use in the vehicle of figure 1.

With reference to figure 1 there is shown a vehicle 10 having doors 12 and 13 with door window glass 14 and 15 and door latches 16 and 17.

The window glass 14 and 15 is moveable in a substantially vertical direction between open and closed positions by power actuators.

Door latches 16 and 17 allow the doors to be releaseably retained in a closed position.

In particular door 12 is a drivers door and includes a key barrel 20., Latch 16 is a lockable latch and can achieve various states of security:- a) Superlocked, where operation of an outside or inside door handle does not open the door, (in particular operation of the any sequence of inside or outside door handles does not open the door).

b) Locked, where operation of an outside door handles does not open the door but operation of an inside door handle does open the door.

c) Unlocked, where operation of either the outside door handle or the inside door handle opens the door.

Door 13 is a rear door and latch 17 is a lockable latch having a child safety feature. Thus latch 17 can also achieve various security states:a) Superlocked b) Locked child safety on, where operation of the inside or outside door handles does not open the door (though operation of an inside door handle followed by operation of an outside door handle may allow the door to open) c) Locked child safety off, where operation of the outside door handle does not open the door but operation of the inside door handle does open the door, d) Unlocked child safety on, where operation of the outside door handle opens the door but operation of the inside door handle does not open the door, and e) Locked child safety off, where operation of the inside or outside door handle opens the door.

Door latches 16 and 17 have a fully closed position and also have a first safety position wherein the door is prevented from opening by the latch but nevertheless is not fully closed.

Latches 16 and 17 have rotating claws which engage with a striker mounted on the B post and C post of the vehicle respectively. Thus the rotating claw can be in a closed position, a first safety position, or an open position. , When the claw is in the first safety position or open position the door is in a corresponding ajar position.

To achieve the various security conditions, closed, first safety and open conditions, various components within the latches 16 and 17 are moved relative to each other.

The present invention allows for the determination of the relative position of various components. Thus where the various components are moved by power actuators, it is useful to be able to determine that a particular component has reached a particular position in order that the power to the power actuator controlling such component may be shut off.

Consideration of figure 2 shows a switch S 1 in the form of a light emitter E which emits light L towards a light detector D. With the switch S 1 in a position shown in figure 2 the light emitted from the emitter and is received by the detector. This provides for a first state of the switch.

The emitter is connected to a first component 22 of the latch 16, in this case a chassis of the latch, and the detector is connected to a second component of the latch 16 which is capable of moving relative to the first component. In this case the second component 24 is a rotating claw of the latch 16 which is in the closed position as shown in figure 2.

When the claw moves to the first safety position 26 or the open position 28, light L emitted from the emitter is no longer received by the detector and thus the switch S 1 achieves a second state.

Consideration of figure 3 shows a second embodiment of a switch S2 for use in the door latch 16 or 17. In this case both the emitter E' and detector D' are fixed on stationary components of the door latch and the rotating claw 24' obstructs light L' from reaching the detector D' in the position as shown in figure 3.

When the rotating claw moves to the first safety position 26' or the open position 28' the claw no longer obstructs light which can be received by the detector D'. Thus the switch S2 can achieve a second state wherein light is blocked from being received by the detector D' and a first state wherein light is received by detector D'.

Consideration of figure 4 shows two- light emitters E 1 and E2 which direct light at respective light detectors D 1 and D2.

In this case a component 30 is positioned between corresponding emitters and detectors and can move in the direction of arrow A from position P1 to positions P2, P3 or P4.

Component 30 has holes 32 which can transmit light when situated between an emitter and detector. Component also has obscure portions 34 (represented by crosses) which do not transmit light when positioned between an emitter and a detector.

With the component 30 positioned in positions Pl, P2, P3 and P4 the detectors D1 and D2 either detect light or receive no light as follows

POSITION DETECTOR D1 D2 P 1 Detects light Detects Ii ht P2 Detects light No light P3 No light Detects light P4 No light No light Thus it can be seen that by using two switches, four independent positions of a component can be detected. Thus the component might be a rotating claw and positions Pl, P2 and P3 might correspond to a closed position, first safety position and open position of the claw.

Consideration of figure 5 shows switches S5, S6 and S7 having emitters E3, E4 and E5 respectively which emit light L3, L4 and L5 respectively towards detectors D3, D4 and D5 respectively. Positioned between the emitters and detectors is a component 38 having light transmitting holes (represented by circles) and obscure portions (represented by crosses).

Component 38 has eight positions (only the first of which is shown) each of which can be determined by considering the state of switches S5, S6 and S7.

It should be noted that with the component 38 in a position shown in figure 5 detectors D3, D4 and D5 all receive light. It should also be noted that with the component 38 moved to the extreme right position, none of the detectors D3, D4 or D5 receive light. Consideration of figure 6 shows switches S5', S6' and S7' having respective emitters E3', E4 and E5' which emit respective light L3', L4' and L5' which is directed towards detectors D3', D4' and D5'. Component 38- is identical to component 38 except it only has six positions rather than the eight positions of component 38. Consideration of the holes and obscure portions of component 38' show that at no time do all detectors receive light. Thus in the position as shown in figure 6 detectors D3' and D4' detect light but detector D5' does not detect light. Furthermore there is no position of component 38' which allows all detectors to detect light. Such an arrangement is particularly beneficial where only six position or less are required to be detected since electronic malfunction is likely to effect all emitters and detectors in the same way. Thus where power fails to a11 emitters E3', E4' and E5' and they emit no light, the detectors would therefore receive no light and under such circumstances this is clearly a malfunction. Contrast this with component 38 where such a sequence of events would cause the electronics to potential erroneously assume that component 38 is in the extreme right position. Clearly, in further embodiments, components equivalent to component 30, 38 and 38' could move in a rotary direction as opposed to a linear direction. Furthermore in further embodiments components equivalent to component 30, 38 and 38' need not comprise a single component. For example when considering figure 4, the component which obscures or allows light to be transmitted from E 1 to D 1 could be a lever and the

component which obscures or allows light to be transmitted from E2 to D2 could be a rotating claw connected to the lever.

Clearly, in further embodiments it is possible to provide N switches which may be used in conjunction to provide for detecting each of at least N + 1 states of an associated component or components. Furthermore to provide for say two switches, it is not necessary to provide two light emitters and two light detectors. Thus for example a single light emitter can be used to emit light, part of which is directed towards a first detector and part of which is directed towards a second detector. Furthermore two light emitters can each direct light towards a single detector, the detector being capable of distinguishing the light from each emitter. For example the first emitter might emit light of a first frequency and the second emitter might emit light of the second frequency with the detector being capable of distinguishing between these frequencies The light emitters could be infrared vertical cavity surface emitting lasers or infrared photodiodes. The light detectors could be infrared phototransistors. Such emitters and detectors use very low power and thus the emitters can remain in a light emitting mode when the vehicle 10 is parked without causing a significant drain on the vehicle battery. The term `light emitting mode' is used here to describe an emitter that permanently emits light and also an emitter that intermittently emits light. Such an arrangement is particularly useful when providing an alarm system for the vehicle since if a thief were to cut a wire in an attempt to bypass the alarm system, this woWd cause a change in state of the switch which could initiate activation of the alarm. The term light as used in this specification is to be understood to mean visible light, ultraviolet light and infra red light.

Claims

Claims 1. A vehicle including a switch in the form of alight emitter and a light detector, in use, lights being transmitted by the light emitter and being received by the light detector to provide for a first switch state and the light not being received by the receiver. to provide for a second switch state.
2. A vehicle as defined in Claim 1 in which the light emitter emits light when the vehicle as parked.
3. A vehicle as defined in Claims 1 or 2 in which the second switch state is provided for by moving the light transmitter relative to the light receiver.
4. A vehicle as defined in Claims 1 or 2 in which the second switch state is provided for by interrupting the light path between the light transmitter and the light receiver.
5. A vehicle as defined in any preceding claim in which the switch includes a laser such as a vertical cavity surface emitting semi conductor laser or an infrared photodiode or an infrared phototransistor.
6. A vehicle as defined in any preceding claim including a door, in which the switch is used to detect the position of door components such as the position of door latch components and/or the position of the door window glass.
7. A vehicle as defined in any preceding claim including N switches used in conjunction to provide for detecting each of at least N + 1 states of an associated component or components.