US3811315A

US3811315A - Apparatus for automatic digital measurement of watch performance by utilizing ticks

Info

Publication number: US3811315A
Application number: US00226438A
Authority: US
Inventors: Y Kunitomi
Original assignee: Citizen Watch Co Ltd
Current assignee: Citizen Watch Co Ltd
Priority date: 1971-02-22
Filing date: 1972-02-15
Publication date: 1974-05-21
Anticipated expiration: 1991-05-21

Abstract

An apparatus for performing automatic digital measurement of the performance of a watch by utilizing a component of the ticks thereof, in which a frequency band of the ticks of the watch is selected, the ratio of signal to noise is improved in that frequency band thereby amplifying the ticks with high fidelity.

Description

United States Patent 1 [111 3,811,315 Kunitomi May 21, 1974 APPARATUS FOR AUTOMATIC DIGITAL [56] References Cited MEASUREMENT OF WATCH UNITED STATES PATENTS PERFORMANCE BY UTILIZING TICKS 2,535,304 12/1950 Lindborg 73/6 [75] Inventor: Yoshio Kunitomi, Tokyo, Japan 3,254,346 5/1966 Alexander 73/6 [73] Assignee: Citizen Watch Co., Ltd., Tokyo, Primary Examiner Richard C Queisser Japan Assistant Examiner-Denis E. Corr [22] Filed: Feb. 15,1972 Attorney, Agent, or Firm-Ladas, Parry, Von Gehr, [2]] pp No: 226,438 Goldsmith & Deschamps [57] ABSTRACT [30] Forelgn Apphcatmn Pmmty Data An apparatus for performing automatic digital mea- Feb. 22, 1971 Japan 46-10282 Surement f the performance of a watch utilizing a Mar. 5, i971 Japan 46-12084 component f the ticks thereof in which a frequency band of the ticks of the watch is selected, the ratio of gill. Signal to noise is improved in that frequency band 0 l I e I s a u e e a u e u n 1 v e u v a e a I a u e e I a e e I I we t [58] Field of Search 73/6, 462 thereby ampl'fymg the fidel'ty 3 Claims, 11 Drawing Figures i A p E AMPLI- AMPLI- g I. H C/fiCU/T mm? I M V 6 T AMPLI- 82?,- A 5 F/Ef? V/BR/Im L 1 I 1 PATENTEDIIAYZI m4 Q 38 1 1.315 sum u (If 5 hFE APPARATUS FOR AUTOMATIC DIGITAL MEASUREMENT OF WATCH PERFORMANCE BY UTILIZING TICKS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to an apparatus for automatic digital measurement of watch performance, in which the ticks of the watch are amplified with high fidelity so as to obtain a high signal to noise ratio, and the time interval between given components of the ticks, for example, the first and third sounds are digitally measured by the use of high frequency impulses.

2. Description of the Prior Art In the conventional method of amplification of the ticks, an amplificiation circuit with semiconductors or vacuum tubes have been employed, and particularly a preamplifier circuit including anequalizer is employed in applying to the first stage including a semiconductor a sound signal detected by a detector element of R- chelle-salt or the like with a relatively low output impedance. Such a sound signal is in most cases applied directly to a control grid when employing an amplifier with vacuum tubes. Therefore, not only an audio frequency band is involved, but also no operation is performed for picking up the ticks with high fidelity. Further, due to the high input impedance of the amplifier, it is impossible to obtain a sufficiently high ratio of the sound signal picked up by the detector element to noise or to input other than the sound signal or to high frequency noise which comes from a power supply. As a result, the conventional apparatus for measuring the performance of the watch by the use of the ticks picked up requires that the amplification factor or the signal of the amplifier be adjusted from the outside. This makes the conventional measuring apparatus almost unreliable and unusable in the unmanned automatic measurement of the performance of a watch.

In addition, when a circuit with a constant amplification factor is employed to detect certain components of the ticks, for example, the first and third sounds among the entire components of the ticks (which include the three sounds of the second-hand driving movement comprising the first sound striking between the roller of a balance wheel and a part ofa jewelled pallet, the second sound striking between a pallet jewel and a tooth of an escapement wheel and the third sound striking between a main partof a jewelled pallet and a banking pin), the employment of a circuit with a constant amplification factor results in the detection of various ticks ranging from the first to third sounds. To cope with this problem, two amplifiers with different amplification factors were employed or the amplification factors for those sounds between the first and third sounds were changed by the feedback operations. In the former method. however, since the same amplification factor is involved for both amplifiers, the first and second sounds are not always picked up accurately by the two amplifiers respectively due to the fact that different watches have different ticks. In the latter method, the fact that each tick has a different magnitude and that the interval between the first and third sounds varies periodically results in slight variations in the amount of feedback, making it impossible to separate the first sound accurately from the third sound. To overcome this disadvantage, the interval between first and third sounds has been indicated on an indicator or oscilloscope by means of a control circuit with low responsiveness. These methods involve many processes requiring actual human labor, and it is difficult to automate them for reasons of job efficiency, measurement errors and yield.

SUMMARY OF THE INVENTION This invention is intended to obviate the abovedescribed drawbacks of the conventional apparatuses, and an object thereof is to provide an automatic instrument for performing accurate and speedy digital measurement of the performance of the watch, for example, the amplitude of a balance-wheel on an unmanned flow line, which comprises a tick amplifier for selecting a frequency band of the tick and for amplifying the tick with high fidelity and with an improved signal-to-noise ratio within said frequency band, said amplifier being soconstructed as to control the passage of the tick, a tick signal discriminating circuit for accurately separating, amplifying and shaping given two signals among the tick signals applied from said amplifier, and a voltage source which cooperates with said discriminating circuit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the watch sound amplifier circuit employed in the apparatus according to this invention.

FIGS. 2 to 6 are diagrams showing the detail of the circuit of FIG. 1.

FIG. 7 is a block diagram showing the balance-wheel amplitude measurement and indication device embodying the invention.

FIGS. 8 to 10 are diagrams showing the principle and detail of the sound separator circuit according to the invention.

FIG. 11 shows a voltage generator circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The apparatus according to this invention will now be explained in detail.

Referring to FIG. 1, the reference numeral 1 shows a detector element, numeral 2 a matching circuit including a semiconductor with a grounded collector for matching with the output resistance of the detector element, the numerals 3, 4 and 7 amplifier circuits for amplifying only the frequency band of the watch sound, numeral 5 a high-pass filter, and numeral 6 a gate circuit which is so set that its gate opens when a monostable multivibrator circuit 8 is deenergized, said monostable multivibrator circuit being triggered by the amplified sound and producing pulse waves.

Generally, the frequency band of the watch sound varies with the size of the watch involved, and the upper and lower limits of the frequency band are determined by the size of the watch, its parts and their materials. It is possible, in the present embodiment, to detect the sound of any watch with high fidelity if an ultrasonic band is selected as the frequency band. The Rochellesalt detector element in general use is relatively low in output resistance and natural frequency and unsuitable for high-fidelity detection of the sound in such a high frequency band. Therefore, the present embodiment employs a detector element with a very high output resistance and natural frequency.

The matching circuit 2 is shown in FIG. 2, in which the symbol C, denotes a coupling capacitor, R, a combined resistance of the equalizer circuit, Z an input resistor for the grounded collector transistor circuit and Z, the output resistance of the detector element. The coupling capacitor C,, for which the input resistance can be increased at those frequencies not higher than the lower limit f,,,,,, of the sound frequency band, is

1 RT fmin n- 1 The amplifier circuits 3, 4 and 7 are shown in FIG. 3, in which the symbol C shows a coupling capacitor, R and R current feedback resistors, R an emitter resistor, C an emitter by-pass capacitor, R a collector load resistor, C a high frequency by-pass capacitor, 2,, an output resistor for the preceding stage and Z, an input resistor for the succeeding stage. The capacitor C for which the input resistor, similarly for C can be increased at the frequencies not higher than the lower limit f,,,,,,, is given as ar fmln( P Re) where p 4/ -l$ u m 112 le/ ai az iil le 32 and h output admittance for grounded emitter and open circuit terminal. The signal amplification factor of the amplifier circuit of FIG. 3 is expressed as avi- 4 l fnm: 2 'fmm From this, it is noted that with the increase in the capacity C the amplification factor for the low frequencies is improved, while with the decrease in the capacity C the amplification factor is improved for high frequencies. Therefore, an appropriate value of C is determined by selecting to, corresponding to the upper limit f of the sound frequency band, while an appropriate value of C is obtained by setting on, at a value corresponding to the lower limit f,,,,,, thereof. By employing the amplifier shown in FIG. 3, the attenuation of frequencies results from the fact that the impedance of C is decreased for the frequencies higher than f while the impedances of C and C rise for the frequencies lower than f,,,,,,. If the above-described minimum frequency f,,,,,, is selected to be the lower limit frequency of the high-pass filter circuit 5 which is shown in detail in FIG. 4, the minimum frequency f,,,,,, is given y f'm'n LGZ u M" 4z -i2 43 439 and the output of the high-pass filter circuit 5 which attenuates at the rate of l8db per octave for the frequencies under f,,,,,, is applied to the gate circuit 6 shown in FIG. 5. The resistance between the emitter and collector of the transistor Tr of the gate circuit varies with the current flowing through the resistor R If the emitter voltage of the transistor Tr is selected by the resistor R in such a manner that it is equal to or slightly lower than the output voltage E, of the filter circuit shown in FIG. 4, the resistance between the collector and emitter is decreased by the current through R thereby making it possible to pass the sound only for the period of time during which current flows in R The monostable multivibrator circuit 8 is shown in FIG. 6, in which the monostable multivibrator MM-I is triggered by the first sound of the ticks, while the multivibrator MM-II is triggered as soon as the multivibrator MM-I is cut off, the multivibrator MM-Il being energized for a period of time slightly shorter than the time intervals of the ticks. Therefore, current applied to R is available from the output of the multivibrator MM-ll immediately before the application of the sound.

As mentioned above, in the watch sound amplifier circuit of the present embodiment, not only the detec' tor element 1 but also the capacitors C in FIG. 2, C C and C in FIG. 3 and C C, and C are selected in accordance with the sound frequency band. Also, the gate circuit is provided as shown in FIG. 5. These facts all combine to permit the signal-to-noise ratio to be raised to 20db or higher within the sound frequency band, while at the same time making possible high fidelity within the same frequency band.

A block diagram of the balance-wheel amplitude digital measurement and indication device is shown in FIG. 7, in which the sound detected by the pick-up 11 is amplified by the sound amplifier circuit 12 including a high-fidelity band amplifier with the signal-to-noise ratio of 20 db or higher and which amplifies the signal within the sound frequency band. The resulting signal is applied to the discriminating circuit 13 which is one of the features of the present invention. In FIG. 9 is shown the relationship between the collector current Ic amplified when base current Ib is applied to transistor 61 used in the discriminating circuit 13 and the current amplification factor h of the same transistor as shown in FIG. 8. From this graph, it is apparent that this transistor has such characteristics that when I0 is great, h is also high, while I1 decreases with the decrease in 1c.

The collector current Ic varies in accordance with base current Ib as is obvious from the equation Ic h lb. In the graph, such base current Ib is applied so as to obtain the current amplification factor h at point 62, and when the first sound is applied, then such collector current is applied so as to reduce the current amplification factor h to point 63. Also, when the third sound is applied, the current amplification factor is raised to point 62 or the neighbourhood thereof by changing the base current Ib. In this way, the signal due to the first and third sounds can be picked up, masking the sound signals included between them.

An embodiment of the discriminating circuit is shown in FIG. 10. The sound signal 65 including the first sound 66 and larger amplitude third sound 67 is applied from a terminal 60 through the capacitor 68 to the transistor 64 having characteristics equivalent to those of the transistor 61 of FIG. 8. The base current lb of transistor 64 consists of the differentiated signal 73 obtained by differentiating the input signal 70 to the input terminal 67 through the capacitor 71 and transistor 72 and is passed through the resistor 72. The collector current Ic of the transistor 64 which flows through the collector load resistor 75 and emitter bias resistor 76 is controlled by the base current lb flowing through the resistor 74, but the voltage of the differentiated pulse 73 obtained from the pulse 70 applied to the input terminal 69 is very low at the instant of time when the first sound is applied, so that very little base current flows, resulting in the collector being cut off. As a result, very little collector current flows, whereby the collector output voltage is maintained at point 79. Under this condition, h is so small that the sound 65 is not amplified. If the voltage E is applied to the input 77 to reduce the intrinsic resistance of the transistor 72 through the resistor 78, the voltage across the capacitor 71 is discharged through the transistor 72. Consequently, the base current in the resistor 74 is increased as the period of time varies. This process is required until a certain voltage is reached, so that the time required for the transistor 64, which was cut off when the first sound 66 was applied, to begin conduction becomes gradually short finally resulting in the transistor 64 being energized, whereupon the collector current Ic as well as 12 increases. The third sound 67 which is larger than the first sound 66 can be amplified even for a small value of 12 Therefore, only the third sound 67 can be amplified accurately, if the transistor 64 begins to get out of the cut-off state and h begins to increase before the third sound is produced. The point 80 repre' sents such a situation.

The amplifier 14 in FIG. 7 is provided for the purpose of differentiating and amplifying the collector signal 81 of the transistor 64 and produces an output signal 82. The monostable multivibrator 15 is trigged by the first sound. The output 17 is connected to the input 69 of the discriminating circuit shown in FIG. 10. When the third sound is not detected, the monostable multivibrator 19 is not triggered and hence the flip-flop 24 is not energized. As a consequence, the output 26 of the flip flop 24 and the output 17 of the monostable multivibrator 15 are supplied to an AND gate 27. The output of the AND gate 27 and a signal of 400 Hz are applied to the AND gate 100 the output of which is, together with a signal of 400 Hz. applied to the E0 voltage generator circuit 34.

An embodiment of the E0 voltage generator circuit 34 is shown in FIG. 11. The pulse 28 which is generated without the third sound being detected causes not only positive counting pulses to be applied to the reversible counter 29 but also positive rotational pulses to be applied to the pulse motor drive circuit 31.

The pulse motor 32 is connected through a gear to a resolver 33. The signal of 400 Hz applied to the input 91 is amplified by the transistor 92 and applied through the matching transformer 93 to the fixed coil 94 of the resolver 33. The rotor coils 95 and 96 are connected in the same phase with each other, and the output of the resolver 33 is applied to the smoothing circuit 36 through the rectifier 35. Then the impedance is lowered by the Darlington circuit consisting of the field effect transistor 97 and the transistor 99, thereby generating the voltage E When the reversible counter 29 stands at zero, the rotational angle of the resolver 33 is set at a value such that the voltage E is changed to voltage E, which enables the discriminating circuit to detect the angular amplitude of about of the balance wheel. The pulse motor 32 rotates in the positive direction on application thereto of the pulse 28, and as a result the rotational angle of the resolver 33 gradually increases, thereby raising the voltage E gradually. When the third sound is detected with the increase in the voltage E the output 16 of the monostable multivibrator 15 in FIG. 7 and the third signal gate an AND gate 18, triggering the monostable multivibrator 19. The output 20 of the monostable multivibrator 19 and the output 16 of the monostable multivibrator 15 are supplied to an AND gate 23, the output of which triggers the flip-flop 24, whereby the output of the flip-flop 24 is stopped, with the result that the gate 27 is closed thereby stopping the pulse 28. Accordingly, the pulse motor 32 stops and the voltage E is maintained constant. The flip-flop 21 is triggered and operated by means of the output 16 of the monostable multivibrator 15, while it is triggered and returned to its original state by the monostable multivibrator 19, the interval between the triggering by the output 16 of the monostable multivibrator l5 and that by the monostable multivibrator l9 constituting the time interval between the first and third sounds. The output 22 of the flip-flop 21, the output 25 of the flip-flop 24, the output 54 of the n-counter 38 for counting the number of measurements of the first and third sounds and the reference frequencies 37 are combined at the AND gate 39 to produce counting pulses, which are frequency-divided by the l/n-counter 40 and applied to the counter 41 to measure the average amplitude of n measurements. The output of the counter 41 is applied to the indication means 55 where the amplitude is indicated in terms of angle. At the same time, the outputvof the counter 41 is applied to the comparator 42, where if the signal is included within the qualification range of amplitude between the set higher and lower limits, the flip-flop 43 is triggered. The qualification and disqualification of the signal are indicated by the AND gate due to the output 44 of the flip-flop 43 and the output 54 of the n-counter and another AND gate due to the

outputs

45 and 54 respectively. The qualified and disqualified signals trigger the flip-flop 49 through the OR gate 48, the output of which, together with the output 56 of the zero signal detector circuit 53 of the reversible counter included in the E voltage generator circuit 34 and a signal of 400 Hz, gates the AND gate 51.

The output pulse 30 of the AND gate 51 is applied to the E voltage generator circuit of 34 in FIG. 7. The pulse 30 is not only used for negative counting operation by the reversible counter 29 (FIG. 11), but is applied to the reversing circuit of the pulse motor drive circuit 31, thereby to rotate the pulse motor in the reverse direction. The pulse 30 disappears and the pulse motor stops when the zero signal detector circuit 53 detects the zero value indicated on the reversible counter 29 and the output 56 stops, resulting in the failure to gate the gate 51. The position at which the motor stops measurement.

It will be understood from the above description that the sound amplifier circuit according to the present invention enables the signal-to-noise ratio within the sound frequency band to be improved to db or higher. In addition, the fidelity within the same frequency band is further improved, thereby making possible a higher degree of amplification. These advantages assure very stable detecting and amplifying operations of the input section of the apparatus according to the invention which is intended for measurement of the watch performance by the use of the ticks thereof. Furthermore, given components of the ticks are accurately separated by the discriminating circuit and re lated circuits employed in the present invention. This discriminating circuit forms the basis for operation of measuring instruments utilizing the ticks of a watch, thereby not only improving the responsiveness of the conventional analog measuring instruments but also making possible digital measurement by the use of impulses. This realizes successfully unmanned operation of the intermittent timing machine, automatic rate checker and adjuster, automatic out-of-beat checker and adjuster, rate selector and amplitude checker.

What is claimed is:

1. An apparatus for automatic digital measurement of the performance ofa watch by utilizing the detected sound of the watch, the watch sound including first, second and third sound components, comprising a detector element (1) having a given output resistance, and a watch sound amplifier circuit comprising a matching circuit (2), including a coupling capacitor (C directly coupled with the detector element (1), for matching with said given output resistance of the element (1), a band pass circuit (3,4) connected to the matching circuit (2) for amplifying only a selected frequency band of the watch sound, the amplifier circuit (3,4) including a coupling capacitor (C31), an amplifying transistor the base of which is connected with one terminal of the coupling capacitor (C31), an emitter resistor (R33) with one terminal of said emitter resistor connected to the emitter of said transistor, an emitter by-pass capacitor (C32) connected between the emitter of the amplifying transistor and the other terminal of said emitter resistor and a high frequency by-pass capacitor (C33) connected between the collector of the amplifying transistor and said other terminal of said emitter resistor, a high-pass filter (5) connected to the amplifier circuit (3,4) for passing only the selected frequency band of the watch sound, and a gate circuit (6) connected with the high-pass filter (5) for controlling the transmission of the watch sound.

2. An apparatus according to claim 1, comprising a discriminating circuit (13) connected to the watch sound amplifier circuit, the discriminating circuit (13) including a first transistor (64) and a second transistor (72), a resistor (74), the emitter of the second transistor (72) being connected to the base of the first transistor (64) through the resistor (74), a first capacitor (71) connected between a first input terminal (69) and the emitter of the second transistor (72), the capacitor (71) and the second transistor (72) differentiating a voltage applied to te first input terminal (69) to supply a differentiated signal to the base of the first transistor 64) as a base bias voltage, and a second capacitor (68) connected between a second input terminal (60) and the base of the first transistor (64), the second input terminal (60) receiving watch sounds from the watch sound amplifier circuit, whereby only a particular component sound of the watch sound can be selected to be amplified.

3. An apparatus according to claim 2, further comprising a voltage generator circuit (34), the voltage of which is applied to the discriminating circuit (13), including a reversible counter (29) for positively and negatively counting pulses fed from the discriminating circuit (13), a pulse motor (32) driven by said pulses, a resolver (33) directly connected with said pulse motor (32) and a rectifying and smoothing circuit (35,36) connected with the rotor coils (95,96) of said resolver, said resolver being rotated in positive direction by applying to said pulse motor a number of impulses equal to that positively counted by said reversv ond transistor.

Claims

1. An apparatus for automatic digital measurement of the performance of a watch by utilizing the detected sound of the watch, the watch sound including first, second and third sound components, comprising a detector element (1) having a given output resistance, and a watch sound amplifier circuit comprising a matching circuit (2), including a coupling capacitor (C2) directly coupled with the detector element (1), for matching with said given output resistance of the element (1), a band pass circuit (3,4) connected to the matching circuit (2) for amplifying only a selected frequency band of the watch sound, the amplifier circuit (3,4) including a coupling capacitor (C31), an amplifying transistor the base of which is connected with one terminal of the coupling capacitor (C31), an emitter resistor (R33) with one terminal of said emitter resistor connected to the emitter of said transistor, an emitter by-pass capacitor (C32) connected between the emitter of the amplifying transistor and the other terminal of said emitter resistor and a high frequency by-pass capacitor (C33) connected between the collector of the amplifying transistor and said other terminal of said emitter resistor, a high-pass filter (5) connected to the amplifier circuit (3,4) for passing only the selected frequency band of the watch sound, and a gate circuit (6) connected with the high-pass filter (5) for controlling the transmission of the watch sound.

2. An apparatus according to claim 1, comprising a discriminating circuit (13) connected to the watch sound amplifier circuit, the discriminating circuit (13) including a first transistor (64) and a second transistor (72), a resistor (74), the emitter of the second transistor (72) being connected to the base of the first transistor (64) through the resistor (74), a first capacitor (71) connected between a first input terminal (69) and the emitter of the second transistor (72), the capacitor (71) and the second transistor (72) differentiating a voltage (70) applied to te first input terminal (69) to supply a differentiated signal to the base of the first transistor (64) as a base bias voltage, and a second capacitor (68) connected between a second input terminal (60) and the base of the first transistor (64), the second input terminal (60) receiving watch sounds from the watch sound amplifier circuit, whereby only a particular component sound of the watch sound can be selected to be amplified.

3. An apparatus according to claim 2, further comprising a voltage generator circuit (34), the voltage of which is applied to the discriminating circuit (13), including a reversible counter (29) for positively and negatively counting pulses fed from the discriminating circuit (13), a pulse motor (32) driven by said pulses, a resolver (33) directly connected with said pulse motor (32) and a rectifying and smoothing circuit (35,36) connected with the rotor coils (95,96) of said resolver, said resolver being rotated in positive direction by applying to said pulse motor a number of impulses equal to that positively counted by said reversible counter, said rectifying and smoothing circuit (35,36) producing a signal voltage proportional to the rotational angle of said resolver, said resolver being rotated in the reverse direction by applying to said pulse motor negatively-counted impulses equal in absolute value to the impulses positively counted by said reversible counter, said reversible counter thereby being returned to a reference position of said resolver occupied prior to the counting operation, the internal resistance of said second transistor (72) being varied by being supplied with said signal voltage to the base of said second transistor.