239 001 P-WO (Amendments) INSIDE LIGHTING CIRCUIT FOR A VEHICLE
s Description The invention relates to a circuit configuration and an apparatus for the interior lighting of the passenger area, luggage or cargo area and glove compartment of io motor vehicles.
In the early days of motor vehicle production, it was state of the art that the vehicle interior lighting was manually operated by a manual switch. Since this was i5 too troublesome as a permanent solution, the manual switch being especially difficult to locate in the dark, the problem was posed of automatically switching on the interior light for entering and leaving the vehicle, the light being automatically switched off again after the 2o action of entering or leaving the vehicle was completed.
The object was solved by a motion detector, comprising the door and a door contact as a sensor, which converts the unavoidable movement of persons entering or leaving the vehicle, namely operation of the door, into an 2s electrical signal which switches on or off the vehicle interior light. Today, the widespread state of the art is a selective switch in the interior of the vehicle with three positions, door contacts which close on opening the doors and also the luggage area and glove 3o compartment, and a timer for delayed switching off of the interior lighting which is triggered when the doors are closed. Re-triggering of this timer is possible by renewed opening and closing of the doors. Furthermore, the ignition system delivers a status signal so that 35 after closing the doors and initiation of the ignition system, the interior lighting - which remains on for a period of time - is switched off. Disadvantages of the prior art hitherto described are that when the selected switch is set to the "light always off" position, the light remains off when the driver opens the vehicle from outside in the dark. He can neither see the ignition lock nor the selective switch and must feel around in the dark with difficulty until he finds the light switch. A further disadvantage is that the contacts in the doors, together with the necessary cabling and plugs, are very expensive, that if the selected switch is inadvertently left in the "always on" position, the battery will become discharged at the latest after one to day and the vehicle would become immobile, and that in the case of the more commonly-used selective switch position "switch light on via door contacts" and a door being inadvertently left open, the battery would also become discharged after one day at the latest, which is also the case should a luggage area or glove compartment also be inadvertently incorrectly closed. Various solutions are listed in DE 3820829 C2, EP 0622271 A2, EP
0138919 and DE 4407616 A1, although no simple and all-embracing solution is provided. DE 29518923 U1 limits 2o itself expressly to the illumination of the engine bay as a method for repelling martens. Furthermore, it is known prior art for sensors to generate an electrical signal when the door lock, the remote control or the central locking are operated, that this signal is 2s supplied to the vehicle interior light and that this light is switched off or on as a result.
EP 0342345 A2 sees a problem with a type of sensor for the vehicle interior lighting which comprises, as 3o described above, a motion sensor with the door as an actuator and a door contact as an end position sensor.
The problem is represented by the cost of the door contact and its installation. The object is to dispense with the door contact and its installation. EP 0342345 3s A2 suggests three solutions, each functionally independent from one another, which do not require each other. The first one provides that air pressure fluctuations are recognised by a signal generator on opening or closing of the door, as the second solution an alternating field (e. g. microwave field, ultrasound field...) generated by a transmitter located in the vehicle interior is to be disturbed by opening of the door and/or people entering or leaving the vehicle, this s disturbance being converted into an electrical switching signal by means of a receiver and a circuit. The third independent solution suggests a W transmitter with a W
detector, wherein disturbance of the generated UV field on opening the door is converted by a sensor and a to circuit into a switching signal for the vehicle interior lighting. The hitherto-known prior art is unsatisfactory, especially the last-mentioned three solution attempts. In practice, a motion sensor which generates electrical signals caused by air pressure 15 fluctuations as a result of movement of the door often delivers an erroneous signal. The suggested motion sensor, which reacts to interruption of an alternating field, is only conditionally usable in the form of the UV motion sensor. W radiation can lead to blindness, a 2o cardboard box on the passenger seat also leads to disturbance of the UV or ultrasound field in the same way as opening of the door, and hence would lead to permanent switching on of the vehicle interior lighting.
Microwaves are continually reflected to and fro by the 2s metal bodywork, penetrate outwards and can e.g. be reflected back by passing vehicles, causing the interior lighting to switch on. JPO 08156683 describes a passive infrared motion sensor which detects the motion of persons outside the locked vehicle in the vicinity of 3o the door lock, and switches on door lock illumination, e.g. integrated into the door lock itself. Since only persons in the vicinity of the door lock on the outside of the vehicle are detected, persons in the locked vehicle interior are not detected. In addition, the 35 door lock is only illuminated on the exterior of the vehicle, illumination of the vehicle interior does not take place.
The object of the invention is to improve the unsatisfactory prior art to the most extensive degree possible in the simplest manner possible. Since the prior art already has an inestimable number of solutions as a result of the many publications, it has at least as s many failings, the object which includes all failings is also just as wide in scope. For this reason, and for the purpose of simplification, the object will additionally be newly worded: if a vehicle user is present and moving, the vehicle interior lighting is to switched on or remains on, if the vehicle user is no longer present or is no longer moving, the light is automatically switched off (again) or remains off.
The invention solves the problems with the 15 characterising features of claim 1. An advantageous expansion is represented by the circuit configuration according to claim 2. Further advantageous embodiments result from claims 3 to 24. The invention is distinguished in that the presence of the vehicle user 2o in the interior of the vehicle is detected directly by one or more infrared motion sensors, wherein the hitherto-known timer is triggered or re-triggered for the time-delayed switching off of the vehicle interior lighting by this or these motion sensors. In this way, 25 It can be detected if the person enters or leaves the vehicle, and also when the person fastens their seat belt, searches for something, etc. It is advantageous if the infrared motion sensor exclusively recognises the movement of persons located in the interior of the 3o vehicle when the vehicle is closed. This can take place by suitable selection of the detection sector of the motion sensor. With tinted glass, the detection sector of the motion sensor can be of any size, since only a fractional portion of the IR radiation from outside can 3s penetrate through tinted glass windscreens. The detection sector of the IR sensor automatically increases in size when the door is opened. In this way, persons in the door opening angle can be recognised and the vehicle interior lights can be switched on.
Many embodiments are conceivable within the framework of the invention. Comfort is increased if the push button switch is designed as a contact switch. Furthermore, it 5 is conceivable to combine the infrared motion sensor, the circuit according to the invention, and the timer, the push button switch and the lights spatially together in a module which can be located in the roof area.
Furthermore, the combination of IR motion sensor or io parts thereof, timer and circuit according to the invention, in an integrated circuit, for example an ASIC, is also conceivable. Furthermore, in the event that e.g. persons wish to spend the night in their vehicle and do not wish to be disturbed by the vehicle internal lighting under any circumstances, a cover which is impermeable to infrared light can be provided which can be pushed over the sensor in order to deactivate it.
It can be desirable for the vehicle interior light to be switched on before the passive infrared motion sensor is 2o triggered. To this end, the timer is also triggered when the central locking is moved from the state "locked" to the state "opened" in order to provide delayed switching off of the vehicle interior light. Furthermore, the invention can be realised via software using logic building blocks such as PALS, GALs, PLDs and/or a microcomputer. In the event that the infrared sensor with the described screen is deactivated, or in the case of extreme climatic conditions where the vehicle interior temperature is close to that of the human body, 3o even at night, and where the infrared motion sensor is not activated, it can nevertheless be desirable to provide a possibility for lighting the vehicle interior.
This is possible by the timer having the facility to be triggered for time-delayed switching off of the vehicle interior lighting via the manual switch as described above. Here, the logic circuit provides that when the timer has timed out and the trigger signal of the manual switch is received, the holding element, as described above, which is provided for storing the switch input remains locked for manual input and that merely the timer is triggered. The holding element is only released for entry by the then-triggered timer when the switch signal has dropped out. Hence the vehicle user s can illuminate the vehicle interior for the specified time of the timer by operating the manual switch when the infrared motion sensor is deactivated. The specified time of the timer is here preferably 25 seconds. The light can be switched off before the timer io has dropped out by operating the manual switch, as otherwise the holding element for the push button switch is released by the timer for entry. Furthermore, comfort is increased if the area of the door sills is illuminated by lamps disposed in the lower area of the is doors. Furthermore, comfort is increased if the switching on or switching off of the vehicle interior lighting is dimmed, that is, if the lights are not switched on and off immediately but are rather gently increased or decreased in intensity.
Furthermore, it is possible that the vehicle interior lighting is only switched on when a provided brightness sensor recognises that brightness has dropped below a defined level. If a plurality of infrared motion 2s sensors are provided in a vehicle interior, according to the invention, it is advantageous, based on the low number of parts and the high number of items in production, if circuit configurations are used which are identical, and which can be combined into a master 3o circuit by means of e.g. master-slave switching or external circuitry. As an example, when using two IR
motion sensors, in each case the evaluation circuit of the passive IR motion sensor, the logic circuit, the holding element, the dimmer control, etc. can be on two s5 identical ASICs. The first ASIC can serve as master, the second as SLAVE. With the first ASIC, for example, the holding element can be connected to a push button switch, on the second ASIC this holding element can, e.g., be deactivated by connecting to GROUND. When only one PIR motion sensor is used, it is also advantageous that individual functions can be deactivated by external switching, depending on the model politics of the vehicle manufacture. Any number of possibilities are s feasible according to the laws of logic operation.
Higher unit numbers of identical electronic components and/or integrated circuits can be realised at correspondingly low unit costs as a result of these standardised components. Furthermore, draining of the io battery is securely prevented by the circuit, according to the invention, as the battery need no longer be "protected" by its own circuit for the glove compartment interior light. The glove compartment interior light can be switched parallel to the vehicle interior light.
i5 A separate switch for the glove compartment interior light is then no longer necessary. Furthermore, it is advantageous, in order to keep the number of infrared motion sensors low, to use optical light conductor systems to collect IR light from areas in the vehicle 2o which cannot directly be seen by a PIR sensor in its defined position, to collect and/or divert and/or convey the IR light so that it can reach the IR sensor. Here, all known optical means can be used such as lenses, mirrors, facetted mirrors, Fresnel lenses, optical fibre z5 cables, etc. comprising all materials known in the field of optics, and the physical laws of reflection, refraction, diffraction and polarisation.
This embodiment of the invention is described in one 3o example: a module is disposed on the vehicle roof between the front seats, containing PIR motion sensors, push button switch, lights, logic circuits, according to the invention, etc. An optical system is provided in the module which collects IR light from all areas which 35 can be reached by the module in a straight line.
Furthermore, facetted mirrors are disposed on the vehicle roof in the housings for the rear seat reading lamps, similar to a shed roof, which divert IR light from the area of the rear seat, optionally collecting it, in such a way that the light can be detected by the IR sensor in the module. In the case of utility vehicles, such a diverting element is provided on the roof above the load bay, optionally with a light-s collecting function, which deflects the IR light from the luggage area in such a way that it can reach the IR
sensor. In the case of limousine models, the IR light in the luggage area is also detected and/or collected and is brought into the vehicle interior by means of an io optical fibre. The IR light enters the vehicle interior in such a position so that it can be detected by the IR
sensor. Strong segmentation of the detection sectors is advantageous with every form of light deflection in order to provide the PIR motion sensor with a sufficient 15 reception signal. Furthermore, it is expedient to dispense with the luggage area contact, which is no longer necessary, and to connect the luggage area interior lighting in parallel with the remaining vehicle interior lighting. In the case of cabriolets, it is 2o advantageous if the IR motion sensor is entirely deactivated when the roof is open, or that it has a reduced detection sector so that persons outside the vehicle are not detected. Furthermore, it is advantageous for use in certain climatic zones if the IR
2s sensor can be cooled by means of a Peltier element.
Advantageously, the Peltier element is switched on if a provided temperature detection system detects a temperature of the IR sensor above a defined temperature, and the brightness sensor, as described 3o above, determines that the brightness in the vehicle is insufficient. Here, it is advantageous if the Peltier element is also used as a temperature sensor with an alternating cooling, measuring and, optionally, pause cycle. It is furthermore expedient, for reasons of 35 energy conservation, if those components with high energy consumption are only provided with current after detection of a vehicle user, with the described invention.
Such a SLEEP mode of the circuit is very easy to realise with a CMOS-based PIR motion sensor. Furthermore, it is expedient for future expansions to provide additional trigger inputs for triggering timers. In addition, s comfort is increased if the individual lamps in the vehicle can be switched separately. The invention is also described with reference to the embodiment example in Figure 1. Connections, supply voltages, pull resistances, capacitors for run-time synchronisation io which are not required for comprehension are not illustrated here for reasons of simplicity. The status signal of the ignition Z is present both at the data input of the D-flip-flop (1) and also at one input of the NEXOR gate (2). The negative output of the D-flip-15 flop (1) is present at the other input of the NEXOR gate (2). The output of the NEXOR component is connected with both the clock input of the D-flip-flop (2) and also with one input of the OR gate (6). Every status alteration of the status signal of the ignition Z leads 2o to parity at the input of the NEXOR gate and hence the output of the NEXOR gate (2) goes high and the D-flip-flop (1) is clocked. The negated data output of the D-flip-flop (1) is inverted by the transfer of the current state of the ignition, the parity of the input signals 2s at the NEXOR gate (2) is then no longer present and the output of the gate then returns to LOW. The push button switch (3) is connected to a voltage which logically corresponds to HIGH. Furthermore, it is connected to one input of the AND gate (7). The other input of the 3o AND gate (7) is connected with the non-negated data output of the timer (7). The output of the AND gate (7) is connected with the clock input of the D-flip-flop (4) and is only logically HIGH when the timer (7) has not yet timed out and the push button switch (3) is pressed.
35 At the D-flip-flop (4), the negated data output is supplied back to the data input so that the contents of the D-flip-flop alter with each LOW-HIGH transition at the clock input. The non-negated data output of the D-flip-flop (4) is connected with an input of the NEXOR
component (5), the other input of which is connected to the status signal of the ignition Z. Hence it is always logically high at the output of the NEXOR component (5) if the ignition is off and the D-flip-flop (4) is not s set via the push button switch (3), or when the ignition is on and the D-flip-flop (4) is set. The reset input of the D-flip-flop (4) is connected to the output of the OR component. Hence an alteration in the status of the motor ignition, that is, each HIGH-LOW transition and to LOW-HIGH transition, leads to resetting of the D-flip-flop (4). The timer for delayed switching off of the vehicle interior lights (7) is, according to the invention, no longer triggered or re-triggered by the door contacts, but rather by the signal IR of an infrared motion sensor. The non-negated data output of the timer (7) is connected with the SET input of the D-flip-flop (10). As long as the timer runs, the D-flip-flop (10) is set. The non-negated data output of the D-flip-flop (10) is connected to the non-negated input of 2o the AND component (9). The other, negated, data input of the AND component (9) is also connected to the non-negated data output of the timer (8). If the timer (8) drops out after a specified time, a logical HIGH
momentarily results at the output of the AND component (9), which resets both the D-flip-flop (10) via its reset input and also, via the OR component (6), the D-flip flop (4) via its reset input. The non-negated signal of the timer (8) is present at one input of the AND gate (11), the output of the NEXOR gate (5) is 3o connected to the other input, the signal L is guided on an amplification circuit according to the current prior art, not illustrated, at the output of the AND component (11) via which the interior lighting is finally switched on. If the timer (8) is triggered by the infrared motion sensor, and if the ignition is off and the holding element (4) is not set by the push button switch, then the lighting is switched on, also if the timer (8) is not yet expired, the ignition is on and the holding element (4) is set by the push button switch (3) .
As a variant of the logic circuit as described, the negated output signal of the D-flip-flop (1) can be s present at the data input of the D-flip-flop (1) instead of the signal from the ignition.
An advantage of the invention is that the vehicle user has light in the vehicle, with the ignition being off, to at least until they have left the vehicle. If the user wishes to turn off the light for whatever reason whilst they are in the vehicle, they need only press the button (3) once. The light remains off for as long as the user is in the vehicle. If required, the light also remains is off when the doors are opened. If the user returns to the vehicle after some time which is longer than the running time of the timer, the light immediately switches on when IR motion detectors detect said user.
As a further advantage, the light is inevitably switched 20 off after the timer times out when the vehicle user is not present. This ensures that the battery is not drained. Furthermore, the use of expensive door contacts is no longer required.