CH644244A - - Google Patents

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Publication number
CH644244A
CH644244A CH262481A CH262481A CH644244A CH 644244 A CH644244 A CH 644244A CH 262481 A CH262481 A CH 262481A CH 262481 A CH262481 A CH 262481A CH 644244 A CH644244 A CH 644244A
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CH
Switzerland
Prior art keywords
sensor
signal
circuit
sensors
control
Prior art date
Application number
CH262481A
Other languages
French (fr)
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CH644244B (en
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Priority to CH262481A priority Critical patent/CH644244A/fr
Publication of CH644244A publication Critical patent/CH644244A/fr

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Classifications

    • GPHYSICS
    • G04HOROLOGY
    • G04GELECTRONIC TIME-PIECES
    • G04G21/00Input or output devices integrated in time-pieces
    • G04G21/08Touch switches specially adapted for time-pieces
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K17/00Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/94Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the way in which the control signals are generated
    • H03K17/96Touch switches
    • H03K17/9627Optical touch switches
    • HELECTRICITY
    • H03BASIC ELECTRONIC CIRCUITRY
    • H03KPULSE TECHNIQUE
    • H03K2217/00Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
    • H03K2217/94Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated
    • H03K2217/96Touch switches
    • H03K2217/96066Thumbwheel, potentiometer, scrollbar or slider simulation by touch switch

Description

The present invention relates to electronic watches; it relates, more particularly, to an electronic watch with a fixed control member.
A control means often used in watchmaking
electronic is the electrical contact actuated by a mobile control member, such as a push-button or a crown. This solution requires the use of an element passing through the watch case, which imposes constructi-v limitations, reduces reliability and increases the manufacturing price of the product. On the other hand, the number of controls, and therefore that of the contacts and control elements required, increases with the number of watch functions. The problem of ordering watches with many functions thus quickly becomes critical because, for obvious reasons of economy and aesthetics, it is hardly possible to use more than four control members. The use of codes, involving sequences in the manipulation of contacts has made it possible to overcome this obstacle at the cost of memorizing ever more complex manipulations.
The introduction into watches of capacitive sensors, already known per se, as control members has made it possible to eliminate certain problems posed by mobile control members and to design data input devices deviating from conventional channels. . For example, as described in communication no. 8 made by JP Jaunin to the 55th Congress of the Swiss Chronometry Society in October 1980, the use of four capacitive sensors arranged in line allows, in a digital watch, to correct the hour or very simply enter a wake-up time. To this end, the watch is put into a correction state using an electric push button, then the information displayed is modified by moving a finger along the line joining the centers of the four capacitive sensors arranged on the case or the glass. of the watch. The displayed number is increased or decreased, depending on the direction of movement of the finger, and its variation is one unit for each passage of the finger over a sensor. A complete movement, scanning the four sensors, therefore varies the display by four units. As this movement can be carried out quickly, a correction, even important, becomes very easy. The number of sensors can be any, but at least three, if the direction of movement of the finger must be determined.
If the use of capacitive sensors for control purposes has been known for a long time, for example in elevators, radio and television sets, their application to watches is recent. This is due, first of all, to the fact that a sensor is formed by an electrode, the surface of which must be large (of the order of that of the part of the finger which activates it) to ensure reliable operation and little sensitive to industrial parasites. In addition, this electrode having to be on the glass of the watch or on an insulating part of the front face of the case, its electrical connection with the circuit, fixed on a module, poses a difficult construction problem.
To be able to use sensors of reduced surface, it is necessary to use elaborate electronic circuits, making it possible to detect with security the small variation of capacity resulting from the activation of the capacitive sensor. Swiss Patent No. 607 872 of the Center Electronique Horloger describes such a circuit in which synchronous detection of a voltage applied to the sensor electrode is used. The amplitude of the detected voltage then varies depending on whether the sensor is activated or not. The risk of false information due to noise caused by industrial parasites of 50 and 100 Hz is even lower in this circuit, the higher the frequency of the voltage applied to the sensor. With an applied frequency of around 8 kHz and careful implementation, the operating reliability can be good. The application of this 8 kHz voltage on the sensor however results in additional consumption.
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shut, close to that of the circuit of a watch with digital display by liquid crystals.
The main object of the present invention is to provide an electronic watch using a fixed control member which has the advantage, compared to capacitive sensors, of being insensitive to electrical noise of any kind, of having a very low current consumption. and to be able to be mounted directly on the watch module.
To achieve this goal, the watch according to the invention, which includes a timepiece circuit;
a time display device, controlled by said circuit;
manual control means for supplying control signals to said circuit; and an electrical source for supplying the timepiece circuit, the display device and the control means, is mainly remarkable in that said means comprise a photoelectric sensor arranged to receive ambient light and providing a signal representative of the intensity of said light and the illumination of which can be interrupted manually to generate said control signals.
The advantage resulting from the use of a photoelectric sensor stems from the fact that such a sensor is, by nature, insensitive to electrical noise, that the electrical signal which it provides requires no electrical energy being produced by the light received by its sensitive surface and, finally, it can be placed in front of a window made in the middle of the watch case, on the same module as the circuit, to which it can be easily connected.
Advantageously, said control means further comprises a compensation circuit connected to receive the signal supplied by the sensor and making it possible to generate said control signals in a manner substantially independent of the intensity of the ambient light.
Other characteristics of the present invention will emerge from the description which follows, made with reference to the appended drawings and giving, by way of explanation but in no way limiting, an embodiment of such a watch. In these drawings:
fig. 1 is a partial schematic view of a photoelectric sensor watch;
fig. 2 shows the watch seen from the side where the windows of the photoelectric sensors are located;
fig. 3 gives the typical characteristics of a photodiode;
fig. 4 shows the circuit of a watch provided with a photoelectric control;
fig. 5 represents the logic signals derived from the main divider of the watch circuit;
fig. 6 shows the diagram of an embodiment of the control circuit associated with the photoelectric sensor; and fig. 7 shows the diagram of another embodiment of the control circuit where the sensors are placed in series so as to make it possible to recharge the battery.
Fig. 1 schematically represents a sectional view of the case of a wristwatch comprising a middle part 101, provided with a window 102 on its front part, a crystal 103 and a bottom 104. Inside the case is a module 105 , fixed to the middle part 101 by means not shown, a display 106, for example with liquid crystal, a connector 107 connecting the display to the module, an integrated circuit 108, a battery 109 and a photoelectric sensor 110 formed by a photo -diode or solar cell, delivering an electrical signal in response to the light it receives.
The sensor 110, which constitutes the sensitive element of the control, is placed opposite the window 102, so as to receive outside light only by this way. It is mounted directly on the module 105, to which it is electrically connected. This possibility of mounting the photoelectric sensor on the module represents an important advantage compared to the use of a capacitive sensor which requires a connection between the module and the electrode (fixed on the glass or the housing).
Fig. 2 shows another view of the watch according to FIG. 1 with the middle part 101, the glass 103 and, in the case of this drawing, four windows identical to the window 102 behind which are arranged four photoelectric sensors 110, 112, 114 and 116. The number of windows and sensors can naturally be arbitrary.
The most often used photoelectric sensor is a photo-diode, also called a solar cell. It is constituted by a junction in a semiconductor material having a sensitive surface of approximately 10 mm2 and has two output terminals corresponding to its cathode and its anode. Fig. 3 shows the typical characteristics of a photo-diode. They express the relation which exists between the current I which crosses the photo-diode, under a tension Y between its terminals, and the illumination E of its sensitive surface, expressed in lux. If the cell outputs on a resistor R, the current variation is transformed into a voltage variation, at least equal to the intrinsic variation produced by the diode when the resistance has an infinite value.
As a photo-diode is only sensitive to light, another advantage of the present invention, compared to a control using capacitive sensors, is its perfect insensitivity to electrical disturbances of all kinds.
If the wearer of the watch obstructs one of the windows 102 with a finger 111, as shown in FIG. 1, the corresponding sensor goes from the lit state to the obscured state. The resulting signals collected on its terminals are used to form control signals for the watch. _
Fig. 4 shows the general diagram of a watch according to the invention. The sensors 110, 112, 114 and 116 are connected to a control circuit 401 which will be described in detail later on with the aid of FIG. 6.
In response to the signals produced by the sensors 110, 112, 114 and 116, the circuit 401 generates logic control signals 629, 630, 631 and 632. These signals appear on outputs of the same name and are applied to a guard circuit. time 402. The obscuration, for example by a finger, of the sensors 110, 112, 114 and 116 causes the control signals 624, 630, 631 and 632 to pass respectively to a high logic level. The timepiece circuit 402 develops, on the one hand, logic signals <&, Ö, O ,, <t> 2, ®3 and <D4 necessary for the circuit 401 and, on the other hand, attacks a digital display 403 intended to indicate the hour.
The circuits 401 and 402 are supplied by a battery 404. Finally, an electrical contact 420, actuated by a push-button, is used to choose the operating mode of the watch.
The timepiece circuit 402 will now be described in detail. A quartz resonator 405 is maintained in oscillation by a circuit 406 to form a time base whose output signal attacks a frequency divider 407. Logic signals A, B, C and D, whose respective frequencies are typically 128 Hz, 64 Hz, 32 Hz and 16 Hz, are derived from the divider 407.
A logic circuit 408 composed of an inverter and AND gates (not shown), makes it possible to develop, from signals A, B, C and D, signals 4>, 3>, ®t, <B2, < & 3 and 04, which are shown in the diagram in fig. 5. Signs A and ®, square in shape, are identical and have a
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7.8 ms period; the signal Ö is a signal in phase opposition with the signal <t "; the signal <5X, formed by positive rectangular pulses of 3.9 ms duration, has a period equal to four times that of the signal <t>, that is to say 31.25 ms; the signals <I> 2, and <P4 are identical to the signal 5> ls except that they are out of phase with respect to the latter, respectively by one, two and three periods of the signal <J>. These logic signals are necessary for the operation of the control circuit 401, as will appear below, and the number of signals <ï> l5 <I> 2, <t> 3, etc. is equal to the number of sensors used.
The output of the divider 407 is connected to one of the two inputs of an AND gate 409, the output of which is in turn connected to one of the two inputs of an OR gate 410. The output of the gate 410 is connected at the input of a front-rear counter 411. This counter has a terminal 421 which determines, depending on whether it is at the high or low logic level, the incrementation or decrementation of its content. A decoder 412 decodes the content of the counter 411 and its output attacks the digital display with seven segments 403. If the logic level of the other inputs of the AND gates 409 and OR 410 is such as the counter 411, whose terminal 421 is supposed to be at the high logic level, receives the output signal from the divider 407, the watch behaves in a conventional manner by indicating the time.
A correction circuit 422 is also incorporated in the time-keeping circuit 402 of FIG. 4. It makes it possible to correct the time of the watch from the logic signals 629, 630, 631 and 632 generated by the control circuit 401 in response to the electrical signals supplied respectively by the sensors 110, 112, 114 and 116.
The passage from the time indication mode to the correction mode is done using the switch 420 which is connected to a flip-flop 419. Each closing of the switch 420 switches the flip-flop 419. At the level top logic of the 419 flip-flop output corresponds to the time indication mode, and, at the low level, the watch correction mode. The output of the flip-flop 419 is connected to an input of an OR gate 414 with two inputs, to the input of an inverter 415 and to an input of the AND gate 409. The output of the OR gate 414 is connected to terminal 421 of the counter 411. The output of the inverter 415 is connected to an input of an AND gate 413 with three inputs whose output is connected to an input of the OR gate 410. The outputs of the control signals 629 , 630, 631 and 632 of circuit 401 are applied to a memory 417 with four inputs and four outputs such as, for example, the RCA memory type 4042. The clock input 423 of this memory 417 is controlled by the logic signal <$. At each high logic level of the signal <5, the information present at the input of the memory 417 at this instant is transferred to its output and remains memorized until the next high level of <P.
The state of the logic control signals 629, 630, 631 and 632 of the circuit 401 can be considered, at a given instant, as being representative of a 4-bit binary number in which the logic signal 629 corresponds, for example, to most significant bit. The binary number, present at the input of memory 417 will be designated by X, and the binary number defined by the state of the outputs of this memory at the same time will be designated by Y. The value of Y is thus that which had X, a clock signal 3> earlier. The inputs and outputs of memory 417 are connected to a comparator 418 having two four-bit inputs and two outputs 424 and 425, such as for example the RCA comparator type 4063. Output 424 takes, for example, the logic low level when X is greater than Y and the logic level high when X is smaller than Y. This output is connected to an input of the OR gate 414. The output 425 delivers a pulse at the instant when the clock signal appears ® as long as X is different from Y at this time. This output is connected to the second input of the AND gate 413. Finally, the four outputs of the memory 417 are still connected to the inputs of an OR gate 416 whose output is connected to the third input of the AND gate 413. The OR gate 416 is used to signal the zero value of the number Y by causing a low logic level to appear at its output.
The operation of the watch in correction mode is determined by a low logic level at the output of the flip-flop 419 in FIG. 4, obtained by actuating the contact 420. One of the inputs of the OR doors 414 and ET 409 is thus brought to a low logic level, while an input of the AND gate 413 is brought to a high logic level, thanks to the inverter 415. The AND gate 409 will therefore block the signal from the output of the divider 407 and stop the watch. The output of the OR gate 414 makes it possible to put the counter 411 in the incrementation or decrementation state, depending on whether the output 424 of the comparator 418 is at the high or low logic level.
We will now consider the state of the control signals 629, 630, 631 and 632 of circuit 401. These signals define the binary number X. If the sensors 110, 112, 114 and 116 all receive light, X is zero and, after a clock signal ®, Y takes the same value. A zero value of Y leads to a low logic level of the output of the OR gate 416. The AND gate 413 is then blocked, because one of its inputs is connected to the output of the gate 416. If the sensor 112, for example, is obscured with a finger it generates a signal which passes the signal 630 of the control circuit 401 to the high logic level. The number X goes at this instant from the value zero to the value 0100, while Y always keeps a zero value. The output 425 of the comparator 418 delivers a signal, which however does not reach the counter 411 because, Y being zero, the AND gate 413 remains closed. A clock signal fl> later, Y takes the same value 0100 as X. The output of the OR gate 416 then goes to the high logic level, which has the effect of opening the AND gate 413. However, as X is equal to Y, no signal appears on output 425 of comparator 418.
If the finger is then moved from the sensor 112 to the sensor 114, obviously, X goes from the value 0100 to the smaller value 0010, while Y always keeps the value 0100. At the moment of the movement of the finger from one next sensor, at the input of comparator 418, X is less than Y. A high logic level thus appears on output 424 of comparator 418. This high logic level is transmitted through the OR gate 414 to input 421 of the counter 411, putting this counter in the increment state. The output 425 of the comparator 418 delivers a signal which, passing through the AND gates 413 and OR 410, increments the counter 411 by one unit. A clock signal ® later, Y will take the same value as X, ie 0010 By again moving the finger from sensor 114 to sensor 116 in the same way as above, X goes from the value 0010 to the value 0001, while Y keeps the value 0010. This has the effect of increasing again by one unit the 411 counter.
On the other hand, if the movement of the finger is made from the sensor 112 to the sensor 110, X goes from the value 0100 to the higher value 1000, while Y remains at the value 0100. As X is, in this case, greater than Y , the output 424 of the comparator 418 goes to the low logic level, putting the counter 411 in the decrementing state. The signal which appears on the output 425 of the comparator in response to this movement of the finger, will therefore decrement the counter 411 by one unit. It should be noted that the proper functioning of the circuit 422 requires that the time for the passage of the finger from one sensor to the next is greater than the period of the logic clock signal €> during a continuous movement of the finger on a series of sensors. Otherwise, in fact, if the signal
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clock remains low during this time, memory 417 will not record the variation of X.
The description which has just been made of the operation of the watch in correction mode has made it possible to highlight that the value indicated by the display 403 can be modified, in more or less, by a simple movement of the finger, in a determined direction, above the sensors 110, 112, 114 and 116.
The electronic control circuit 401 of FIG. 4 will now be described in detail in a preferred embodiment using the diagram in FIG. 6. Its purpose is to make the logic control signals which appear at its output independent, to a large extent, of variations in ambient light illuminating the sensors.
As shown in fig. 6 the four photo-diodes 110, 112, 114 and 116 have their cathodes connected to a ground point 601 and their anodes respectively to the drains of four transistors 602, 603, 604 and 605 whose control electrodes or grids are connected to circuit 401 to receive them the signals 4> 15 <D2, <D3 and <P4 respectively. These transistors are field effect transistors operating in switching mode. They are in the blocked, non-conducting or open state when the grid potential is less than or equal to the source potential. This means, for example, that transistor 602 is open when the potential of <ï>! is equal to or less than the potential of point 606. The saturated state, passing or closed, is obtained by applying to the grid a potential greater than that of the source. These devices therefore behave like switches. A resistor 600, connected between points 601 and 606, makes it possible to operate each sensor 110, 112, 114 and 116 under load conditions for which the voltage variation at point 606 is maximum for a given variation of light.
The direct input, marked by a + sign, of a differential amplifier 612 is connected to point 606. The reverse input marked by a - sign of this amplifier is connected to its output 613 so that it behaves as a follower unity gain voltage, having a high input impedance and a low output impedance. Point 613 is, on the other hand, connected to the drains of the two field effect transistors 607 and 608 operating as a switch. The source of transistor 607 is connected, on the one hand, to one of the electrodes of a capacitor 615, the other electrode of which is connected to ground 601 and, on the other hand, to the reverse input marked by a sign - , a second differential amplifier 616 having a positive gain G. The gain G is chosen to be high enough to saturate the amplifier 616 and allow its output 623 to take two well defined logic levels.
The source of transistor 608 is connected, on the one hand, to one of the electrodes of a second capacitor 618 and, on the other hand, to the drain of a field effect transistor 610 operating as a switch, the source of which is connected , on the one hand, to an electrode of a third capacitor 620 and, on the other hand, to the direct input, marked by a + sign, of the differential amplifier 616. A field effect transistor 609, operating as a switch, has its drain connected to one of the terminals of a generator 621 supplying a DC voltage V0. The other terminal of this generator is connected to ground 601. The gates of transistors 607, 608 and 609 are all controlled by the logic signal $ of circuit 401. The source of transistor 609 is connected, on the one hand, to the second electrode of the capacitor 618 and, on the other hand, to the drain of a field effect transistor 611 operating as a switch. The source of the latter transistor and the second electrode of the capacitor 620 are put together to ground 601 ..
The output 623 of the differential amplifier 616 is connected to the inputs of four memories 624, 625, 626 and 627 whose clock inputs are connected to the circuit 401 to receive the logic signals ®2, $ 3 and <D4 respectively. Each of these memories, when its clock signal is at a high logic level, retains the logic state present at this instant on its input 623 and makes it appear at its output. On the other hand, when the clock signal is at the low logic level, the state of the memory output is not influenced by the state of its input 623. The outputs 629, 630, 631 and 632 of the four memories are connected to the four inputs of a NOR gate 633, the output of the latter is connected to a first input of an AND gate 635, the second input of which is connected to circuit 401 to receive the logic signal î>. The output of the AND gate 635 is connected to the control gates of the transistors 610 and 611.
To describe the operation of the control circuit shown in fig. 6, two cases will be considered. In the first, it will be assumed that all the photoelectric sensors receive substantially the same ambient light, which is however liable to undergo fluctuations. In the second case, we will examine what happens when one or more sensors are hidden by a finger.
When the sensors 110, 112, 114 and 116 are uniformly lit, substantially the same electrical signal is created at their terminals. Each sensor is successively and periodically connected to the resistor 600 using switches 602, 603, 604 and 605, controlled respectively by these logic signals <DX, <D2, ®3 and <D4 in FIG. 5. Successive voltages Vj (j = there 4), substantially equal to each other, then appear at point 606 of the resistor 600. Referring to FIG. 5, we see that at time ti the signals <3> i and $ close the switches 602 and 607 respectively, transferring to the capacitor 615, via the unit gain amplifier 612, the voltage created at this instant at point 606 by the sensor 110. At instant t'j the switches 602 and 607 open, isolating the capacitor 615 which keeps its charge until instant t2. At this instant, the signals cD2 and $ in turn close the switches 603 and 607, allowing the transfer to the capacitor 615 of the voltage produced at point 606 by the sensor 112.
In the same way, the logic signals î> 3, <t> 4 and $ will transfer to the capacitor 615, at times t3 and t4, the voltages produced by the sensors 114 and 116, after which the cycle will start again with the signals CD " and the sensor 110. The same reasoning, applied to the capacitor 618, shows that the voltage across its terminals will be V, - 'V0 (j = 1 to 4), V0 being worth a few tens of mV, at times tl512, t3 and t4, thanks to switches 608 and 609, the gates of which are controlled by the logic signal <J>.
For the following description of the operation of the control circuit of FIG. 6, it will be assumed that the input 634 of the AND gate 635 is maintained at a high logic level after its connection with the output of the NOR gate 633 has been interrupted at point P. The output of the AND gate 635, will then be at the high logic level at the same time as the signal ® applied to the input 636 of this door, that is to say at the instants t'ls t'2, t'3 and t'4 at which, d On the other hand, as we have seen, the switches 608 and 609 are open. At times t2, t2, t3 and t4 the situation is reversed, the switches 608 and 609 being closed and the switches 610 and 611 open. Thus during the time intervals from ti to t'j, t2 to t'2, t3 to t'3, t4 to t'4, of duration T / 2, the capacitor 618 is charged at voltages V — V0 (j = 0 to 4), while during the intervals from t ^ to t2, t'2 to t3, t'3 to t4, t'4 to t5, also of duration T / 2, the two capacitors 618 and 620 are connected in parallel. This operation corresponds to that of a network with two switched capacitors, which we know to simulate an RC low-pass filter (see article s
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by J.T. Caves et al. "Sampled analog fïltering using switeched capacitors as resistor equivalents". IEEE J. Solid-State Circuits vol SC-12, Dec 1977). By designating by C618 and C620 the capacitors of capacitors 618 and 620, the time constant of the filter is equal to x = T.C618 / C620. For a time constant t of the order of 50 ms, as T is approximately 7.8 ms we see that C618 must be approximately 10 times greater than 620. It results from this filtering that the voltage across the capacitor C620 is equal to the time average voltage V of the voltages V — V0 produced by the sensors under given ambient lighting conditions. If the sensors are identical and the ambient lighting is fixed or varies slowly compared to the duration of approximately 32 ms of the measurement cycle of the four sensors and the time constant t of 50 ms of the filter, which is generally the case, we have practically V = V — V0.
Under these conditions, the differential amplifier 616 of gain G receives, on its direct input the voltage V and, on its inverse input, the voltage Vj. The voltage at its output 623 is thus equal to G (V-Vj) = - GV0. This voltage is negative and it corresponds to a low logic level. This logic level is transferred to memories 624, 625, 626 and 627 at times t1; t2, t3 and t4 respectively by the signals <Dt, ®2, <J> 3 and d> 4. The outputs 629, 630, 631 and 632 of these memories will take the same low logic state at the same times and, being connected to the inputs of the NOR gate 633 will cause a high logic level to appear at the outputs. It is precisely this logical level which was supposed to exist on the input 634 of the AND gate 635 at the time of the cut at point P of the connection between this input and the output of the NOR gate 633. This connection between the doors 633 and 635 can thus be restored without disturbing the operation of the circuit, which, in response to the electrical signals generated by the uniformly illuminated sensors, therefore develops an average voltage V across the terminals of the capacitor 620, representative of the intensity of the illumination ambient.
We will now examine how the circuit in fig. 6 to a very rapid variation of the ambient light. If this variation is made in the direction of an increase in intensity at time t! for example, then the voltage Vj (j = 1) increases to a value V'1; while the voltage V remains constant, since the switches 610 and 611 are open in the time interval going from tx to tV The voltage at the output 623 of the amplifier 616 then equals G (Vj-Vq-V'x) and, being less than - GV0, it confirms the low logic level already existing at the input of memories 624, 625, 626 and 627. The circuit therefore continues to operate in this case without disturbance.
On the other hand, if the light intensity undergoes a sudden decrease at time t1; the voltage Vj (j = 1) drops to the value V "l5 while V remains constant. A voltage G (Vj-Vq-Vj) then appears at point 623. It can be positive and give a high logic level to the input of the memory 624 if Vj is greater than Vo + V'V The output 629 of this memory takes the same state, and consequently, the door NON-OÙ 633 has three inputs at the same low logic level and a logic input The output of this gate 633 then goes to the logic low level, causing a logic level also low at the output 637 of the AND gate 635,
regardless of the logic level of Ö on input 636. As a result, the switches 610 and 611 remain open even between t'j and t2, causing a blockage of the circuit. Indeed, the capacitor 620 can no longer be charged at the voltage corresponding to the new illumination, even after the outputs of the other memories 630, 631 and 632 have passed to the high logic level. In practice, the danger of blocking the circuit is very low, since it is possible to choose the voltage V0 supplied by the generator 621 so that it is greater than the variation of V "j between tt and tV If this condition is not however not filled and that the circuit is blocked, the voltage V across the terminals of the capacitor 620 decreases slowly due to inevitable leakage currents, allowing the restarting of the circuit after a certain time.
We will now consider the case where certain sensors of the circuit of FIG. 6 are voluntarily masked, for example by a finger, in order to introduce into the watch a control signal. We will first assume that it is the sensor 110 which is suddenly obscured at time tx. The electrical signal generated by this sensor then drops in intensity and reveals a voltage Vj at the terminals of the resistor 600, the switch 602 being closed. This voltage is significantly lower than the voltage V1 which existed at this point a period of Oj earlier, when the sensor 110 was still fully lit. During the time interval from ti to t '!, the voltage v1 is transmitted to the capacitor 615 since the switch 607 is also closed. The switches 610 and 611 being on the other hand open, the average voltage V across the terminals of the capacitor 620 corresponds to that which had been produced by the full illumination of all the sensors, and it is practically equal to V ^ Vq. The voltages v1 and Vt-Vo being applied to the inputs of the differential amplifier 616, it appears at its output the positive voltage G (Vj-Vq-V!), Because normally V! is greater than Vq + Vj. This positive voltage corresponding to a high logic level applied to the input of memory 624, the same logic level is found at output 629. The other sensors 112, 114 and 116, receiving full light, there corresponds to them a logic level low at the output of the amplifier 616 and on the outputs 630, 631, 632 of the memories 625, 626, 627 for the same reasons as those already explained in the case of the uniform lighting of all the sensors. Consequently, one of the inputs of NOR gate 633 is at a high logic level, while the other inputs are at a low logic level. This results in a low logic level at the output of gate 633. This output being one of the inputs of AND gate 635, the output of this latter gate takes an equally low logic level, whatever the level of the logic signal O on l 'input 636. Finally, the low logic level at the output of the AND gate 635 puts switches 610 and 611 in the open state.
It follows that, as soon as the sensor 110 is obscured at time t !, the output 629 of the memory 624 goes to the high logic state, the outputs 630, 631, 632 of the memories 625, 626, 627 remaining at the logical low state. The switches 610 and 611 open and isolate the capacitor 620, which keeps in memory the voltage V corresponding to the ambient lighting. This state of the control circuit is maintained as long as the sensor 110 is not lit again or that the capacitor 620 has not been discharged sufficiently by the leakage currents to cause high logic levels on the outputs 629, 630 , 631 and 632.
It should be noted, on the one hand, that the choice of the value V0 of the generator 621 results from a compromise between the danger that the circuit becomes blocked during an abrupt reduction in the ambient light, as that had already been examined in the case where V0 is too low, and the disadvantage of a loss of sensitivity of the sensors if V0 is too high. Indeed, a sensor is active if the quantity G (Vj-Vq-V!) Becomes positive. This condition is fulfilled if Vj-Vj is greater than V0. Now Vj-Vj defines the sensitivity of a sensor, which is all the better as V ^ Vj is small. As a result, for a sensor to be active and sensitive, the voltage V0 must be low. On the other hand, if the darkening of the sensor 110 occurs at a time which falls outside the time interval going from ti to t '] then the circuit keeps its state until the next signal <ï> i and the described process will
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triggered from time t5, as shown in fig. 5, ie with a maximum delay of three and a half periods of the signal <5, corresponding to approximately 27 ms.
Finally, if several sensors are obscured simultaneously, for example, sensors 110 and 114, the circuit reacts in a similar manner to that described in the case of a single obscured sensor, except for the fact that two memory outputs, at instead of only one, will take a high logic state, namely the outputs 629 and 631, the outputs 630 and 632 remaining at the low logic level. In particular, the obscuration of all the sensors results in a high logic level on all the outputs.
In summary, the operation of the control circuit 401, the outputs 629, 630, 631 and 632 of which correspond respectively to the sensors 110, 112, 114 and 116 connected to this circuit, is as follows. Illumination of a sensor by ambient light causes a low logic level of control on the corresponding output, while its obscuration, that is to say its activation by a finger, results in a high logic level on the same output . In addition, the circuit is capable of operating in a wide range of ambient lighting, thanks to the permanent measurement by the sensors of its average intensity.
In the description of the operation of circuit 401, the state of illumination or obscuration of the sensors did not change over time. This corresponds to static operation. Dynamic operation is also possible. It is where the finger of the watch wearer moves so as to obscure the sensors 110, 112, 114, 116 in a certain order. The only condition is that the transition time from illumination to obscuration of a sensor, or vice versa, is greater than the signal period <$ !, 5) 2, <D3, ®4 so that the circuit can save this change.
In the circuit of fig. 6 there are four sensors 110, 112, 114 and 116 to which the outputs 629, 630, 631 and 632 correspond respectively. But it is obvious that this circuit remains usable with a single sensor. If we consider, for example, the sensor 116, the dotted line 638 delimits the part of the circuit and the output 632 which correspond to it. The signals ®i, ®2and®3 are then no longer necessary and the signal ®4 can be of the same period and of the same phase as the signal <5 of FIG. 5. The NOR gate 633 has only one input, the others can be considered to be in the low logic state. The function of this door is therefore reduced to that of a NO door. The introduction of several distinct commands into a watch by a single sensor can only be done using a manipulation code. A decoder circuit, such as that described, for example, in Swiss patent application no. 617 059, must then be installed on the timepiece circuit 402 of the watch shown in FIG. 4 and be connected to the output 632 of the control circuit 401.
Note that in the case of four sensors, the control circuit can be formed of four circuits 638, one for each sensor. This way of doing things is not very economical in terms of number of components. A different method, called multiplexing, was used in fig. 6. In this diagram, a single circuit 639 can be isolated between the sensors 110,112, 114,116 and the memories 624, 625, 626, 627. This circuit is then used sequentially, first to successively read the information provided by each sensor , then to process it in order to eliminate the influence of variations in ambient light and finally to transmit it to the corresponding memory. This is achieved by periodically connecting each sensor to the common point 606 using switches 602, 603, 604 and 605, controlled respectively by logic signals 02,
®3 and ®4, the same signals also controlling, in the same order, memories 624, 625, 626 and 627 which memorize the information received and make it appear in the form of control signals on outputs 629, 630, 631 and 632.
The arrangement of the photoelectric sensors 110, 112, 114, 116 in FIG. 6 corresponds to their parallel connection, all the cathodes being joined to the ground point 601.
This configuration lends itself well to a sequential reading of the signals supplied by the sensors with a view to their processing by multiplexing. Indeed, it requires only one read switch per sensor, namely switches 602, 603, 604 and 605, respectively, for sensors 110, 112, 114, 116.
If the sensors are photo-diodes, it appears in fig. 3 that the energy which they are capable of providing under favorable lighting conditions is of the order of a few micro-watts. This energy is in principle sufficient to operate the watch circuits, but it is only available in each sensor at a voltage of around 0.5 V in the best of cases. Such a voltage is too low to allow direct charging of the battery 404 of the watch shown in FIG. 4.
A series arrangement of the photoelectric sensors makes it possible to obtain a higher voltage. It may then be sufficient to directly recharge a battery or an accumulator.
Such an arrangement of the sensors and the associated circuit will now be described in a preferred embodiment with four sensors using the diagram in FIG. 7. In this drawing, the cathode of a sensor 116 is connected to the ground point 601 and its anode is connected to the cathode of a sensor 114. The anode of the sensor 114 is likewise connected to the cathode of a sensor 112. Finally, the anode of sensor 112 is connected to the cathode of a sensor 110, the anode 701 of which is thus brought to a voltage equal to the sum of the voltages of each sensor. The voltage existing at point 701 is used to charge the battery 404 through a conventional circuit 702 known per se, such as that described in Swiss patent application no. 607 813. This circuit makes it possible to limit the charging current in the battery 404 and to prevent it from discharging when one or more sensors are obscured. The circuits 401 and 402 are connected to the battery 404 by a connection 703. The source of a transistor 704 is connected to the point 701 and the drain of this transistor is connected to the source of a transistor 705. The drain of the transistor 705 is connected to the direct input 606 of the amplifier 612. The source of a transistor 708 is connected to the cathode of the sensor 110 and the drain of this transistor is connected to the source of a transistor 709. The drain of the transistor 709 is connected to point 606. The source of a transistor 706 is connected to the ground point 601 and the drain of this transistor is connected to the drain of a transistor 707. The source of transistor 707 is connected to the drain of transistor 708. A capacitor 724 connects the drains of the transistors 704 and
707. A resistor 720 connects the drains of the transistors 704 and
708. The source of a transistor 712 is connected to the cathode of the sensor 112 and the drain of this transistor is connected to the source of a transistor 713. The drain of transistor 713 is connected to point 606. The source of a transistor 710 is connected to ground point 601 and the drain of this transistor is connected to the drain of a transistor 711. The source of transistor 711 is connected to the drain of transistor 712. A capacitor 725 connects the drains of transistors 708 and 711. A resistor 721 connects the drains of transistors 708 and 712. The source of a transistor 718 is connected to the cathode of the sensor 114 and the drain of this transistor is connected to the source of a transistor 719. The drain of transistor 719 is connected to point 606. The source of a transistor 714 is connected to earth point 601 and
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the drain of this transistor is connected to the drain of a transistor 715. The source of transistor 715 is connected to the drain of transistor 718. A capacitor 726 connects the drains of transistors 712 and 715. A resistor 722 connects the drains of transistors 712 and 718. A capacitor 727 connects the drain of the transistor 718 to the ground point 601. The gates of the transistors 704, 707, 708, 711, 712, 715 and 718 are all controlled by the logic signal <5. Similarly, the gates of transistors 705 and 706 are controlled by the logic signal ®15 the gates of transistors 709 and 710 by the logic signal ®2, the gates of transistors 713 and 714 by the logic signal <É> 3 and the gate of transistor 719 by logic signal ®4. The form of the logic signals <B, "Jj, <t2, <P3 and <I> 4 is that shown in FIG. 5 and their amplitude is assumed to be sufficient to operate each transistor as a switch, in the same way as the transistors found in the diagram in FIG. 6. The use of a voltage booster circuit is necessary to obtain the amplitude required for these signals. This voltage booster circuit is not shown in FIG. 7, but it is known per se and can be installed in the circuit 402 of the watch. Resistors 720, 721, 722 and 723 serve as load for the sensors and make the single load resistance 600 superfluous.
The description of the operation of the circuit in fig. 7 will be made by first considering how is transmitted, for example, the signal generated by the sensor 112 to the amplifier 612. Referring to the logic signal diagram of FIG. 5, we see that at instant t'j, the signal î> goes to the high logic level, while the signal <J> 2 is at the low level. The switches 708, 711 and 712 therefore pass from the open state to the closed state, while the switches 709 and 710 remain open, the logic level of <t> 2 being low. The voltage at the terminals of the sensor 112 is thus applied to the capacitor 725. The load resistor 721 makes it possible to optimize the variation in the voltage at the terminals of the sensor as a function of the variation in the illumination. At time t2, the logic level io of ® goes to the low level and that of <t2 goes to the high level. The switches 708, 711 and 712 open and isolate the capacitor 725, charged at the voltage of the sensor 112. The switches 709 and 710 on the other hand close. Switch 709 puts one of the electrodes of capacitor 725 at ground point 601, while switch 709 transmits the voltage from the other electrode to input 606 of amplifier 612.
Now considering the circuit of fig. 7 overall, it can be seen that at each high level of the logic signal <5, the capacitors 724, 725 726 and 727 are charged respectively at the voltages of the sensors 110, 112, 114 and 116. The voltages of these capacitors are thus transferred cyclically, and in the same order, to the amplifier 612 using the logic signals <£> x, ®2, €> 3 and 04. These voltages are then processed by the circuit of fig. 6 in the same way as in the case of the parallel connection of the sensors.
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4 sheets of drawings

Claims (10)

  1. 3
    644 244 G
    CLAIMS 1. Electronic watch comprising:
    - a timepiece circuit;
    - a time display device, controlled by said circuit;
    - manual control means for supplying control signals to said circuit; and
    - an electrical source for supplying the timepiece circuit, the display device and the control means, characterized in that said means comprise a photoelectric sensor arranged to receive ambient light and providing a signal representative of the intensity of said light and the illumination of which can be interrupted manually to generate said control signals.
  2. 2. Electronic watch according to claim 1, characterized in that said photoelectric sensor is a photodiode.
  3. 3. Electronic watch according to claim 1, characterized in that said control means further comprise a compensation circuit connected to receive the signal supplied by the sensor and making it possible to generate said control signals substantially independently of the intensity of ambient light.
  4. 4. Electronic watch according to claim 3, characterized in that said compensation circuit comprises:
    - Means for obtaining an average electrical signal, representative of the time average of the signal supplied by the sensor; and
    - a comparator to periodically compare the sensor signal to said average signal and provide a control logic signal when the difference between the sensor signal and the average signal exceeds a predetermined value.
  5. 5. Electronic watch according to claim 4, characterized in that the means for obtaining said average electrical signal comprise a low-pass filter with switched capacitors.
  6. 6. Electronic watch according to claim 1, characterized in that said control means comprise a plurality of photoelectric sensors whose lighting can be manually interrupted individually to generate said control signals.
  7. 7. Electronic watch according to claim 6, characterized in that said photoelectric sensors are photo-diodes.
  8. 8. Electronic watch according to claim 6, characterized in that said control means further comprise a compensation circuit connected to receive the signals supplied by the sensors and making it possible to generate said control signals substantially independently of the intensity of ambient light, and multiplexing means for cyclically applying the signal supplied by each sensor to the compensation circuit.
  9. 9. Electronic watch according to claim 6, characterized in that said sensors are connected in series.
  10. 10. Electronic watch according to claim 9, characterized in that it comprises means, connected to the extreme terminals of said sensors connected in series, for recharging said power source.
CH262481A 1981-04-22 1981-04-22 CH644244A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CH262481A CH644244A (en) 1981-04-22 1981-04-22

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
CH262481A CH644244A (en) 1981-04-22 1981-04-22
EP82810154A EP0064025B1 (en) 1981-04-22 1982-04-07 Electronic watch having fixed control means
DE8282810154T DE3265357D1 (en) 1981-04-22 1982-04-07 Electronic watch having fixed control means
JP57064825A JPS57182689A (en) 1981-04-22 1982-04-20 Electronic clock
HK68190A HK68190A (en) 1981-04-22 1990-08-30 Electronic watch having fixed control means

Publications (2)

Publication Number Publication Date
CH644244B CH644244B (en)
CH644244A true CH644244A (en) 1984-07-31

Family

ID=4237943

Family Applications (1)

Application Number Title Priority Date Filing Date
CH262481A CH644244A (en) 1981-04-22 1981-04-22

Country Status (5)

Country Link
EP (1) EP0064025B1 (en)
JP (1) JPS57182689A (en)
CH (1) CH644244A (en)
DE (1) DE3265357D1 (en)
HK (1) HK68190A (en)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0163138A1 (en) * 1984-05-21 1985-12-04 Energy Conversion Devices, Inc. Touch sensitive keyboard input device and method
CA1222873A (en) * 1984-05-29 1987-06-16 Peter C.J. Parsonage Electronic switch
US4764910A (en) * 1985-03-08 1988-08-16 Citizen Watch Co., Ltd. Electronic timepiece
DE4336669C1 (en) * 1993-10-27 1994-12-15 Ziegler Horst Input field
DE19654853A1 (en) * 1996-05-23 1997-11-27 Ziegler Horst Optical data transmission and reception circuit using light emitting diode
DE10146996A1 (en) * 2001-09-25 2003-04-30 Gerd Reime Circuit with an opto-electronic display content
JP2004257797A (en) * 2003-02-25 2004-09-16 Seiko Instruments Inc Sensor device and electronic timepiece
FI20085022A0 (en) 2008-01-11 2008-01-11 Navigil Oy computer Equipment
WO2015062895A2 (en) * 2013-10-30 2015-05-07 Koninklijke Philips N.V. Wearable electronic notification system

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3823551A (en) * 1971-05-03 1974-07-16 Riehl Electronics Corp Solid state electronic timepiece
US3832056A (en) * 1972-03-13 1974-08-27 Aga Corp Distance measuring device using electro-optical techniques
FR2286375A1 (en) * 1974-09-26 1976-04-23 Akmansoy Fazli Opto-electronic detector for optical barrier - has pass band filter in output providing gain reducing feedback for parasitic signals
CH607872A (en) * 1976-11-04 1978-12-15
SE402394B (en) * 1976-12-03 1978-06-26 Bergstroem Arne OPTOELECTRONIC CIRCUIT ELEMENT
US4242676A (en) * 1977-12-29 1980-12-30 Centre Electronique Horloger Sa Interactive device for data input into an instrument of small dimensions
CA1123064A (en) * 1978-03-23 1982-05-04 William C. King Optically coupled field effect transistor switch
DE2814934A1 (en) * 1978-04-06 1979-10-11 Borsi Kg F Wireless switching of electric equipment through shop window glass - with photodiode inside window which is controlled by light from outside

Also Published As

Publication number Publication date
EP0064025B1 (en) 1985-08-14
EP0064025A1 (en) 1982-11-03
HK68190A (en) 1990-09-07
JPS57182689A (en) 1982-11-10
DE3265357D1 (en) 1985-09-19
CH644244B (en)

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