A method for testing the kinematic display chain of a portable watch or the portable watch body located downstream of an oscillator.

Abstract

This provides a method for testing portable watches, including those with displays. [Solution] One aspect of the present invention relates to a method for testing the display of a portable watch body, wherein the portable watch body is made to keep time continuously for 24 hours, and an initial optical image of the hands is taken with respect to a fixed point at the initial time. At least 24 hours later, at the final time measured by a reference clock, a final optical image of the hands is taken with respect to the fixed point. The position of the hands at the initial time and the final time is determined by a visual recognition means, the difference between the reference position on the reference clock and the actual position of the hands is calculated, and the value of the deviation of the measured state is displayed.

Description

Technical Field

[0001] The present invention relates to a method for simultaneously testing a kinematic display chain downstream of an oscillator in a portable timepiece (e.g., a wristwatch, a pocket watch) or a portable timepiece body by tests commonly performed in the field of timepieces in a series of test stations.

[0002] The present invention relates to the field of timekeeping and state testing of timepieces.

Background Art

[0003] In order to ensure a certain level of chronometer accuracy, it is essential to perform a timekeeping test before completing the portable timepiece body or the portable timepiece. In the case of a mechanical portable timepiece, such a timekeeping test focuses on the quality of the oscillator. However, the display accuracy is ensured by a state test and is related not only to the oscillator (or regulator) but also to the power mechanism, the display setting mechanism, and all drive trains, particularly the final train and the drive mechanism of the indicator, especially the hands. Slack in the gears can cause uncertainty in the visual measurement of these indicators and hands. The influence of slippage at the pivot of the indicator or hand is usually much greater than the measurement uncertainty. Finally, as one of the most serious cases, there is an error in the transmission mechanism (number of teeth), and if one tooth breaks, it can lead to a delay of more than 100 seconds per day.

[0004] Thus, even if the performance of the oscillator is optimal, it may be rendered meaningless by purely mechanical or kinematic defects such as a decrease in roundness, insufficient lubrication, damaged or chipped teeth, loose gears, slipping at the pivot, rubbing of the hands, and other defects.

[0005] Therefore, it is important to perform display synchronization tests on the portable watch body or the portable watch itself that has a mechanical movement. Furthermore, traditional display tests performed when setting the time are generally unrelated to the transmission of the display when the portable watch is functioning, from a design perspective.

[0006] Since the kinematic display chain is tested individually, the measurement test of the condition of the portable watch or the portable watch body can be performed without the display of the portable watch or the portable watch body, and therefore only on the regulator. [Overview of the project] [Problems that the invention aims to solve]

[0007] Thus, the present invention proposes performing a display synchronization test to avoid shipping timekeeping devices that have any of the above-mentioned defects. [Means for solving the problem]

[0008] In view of these circumstances, the present invention relates to the method described in claim 1.

[0009] The purpose, advantages, and features of the present invention will become clearer by reading the following detailed description while referring to the attached drawings. [Brief explanation of the drawing]

[0010] [Figure 1] The diagram shows a specific sequence suitable for use in the present invention, in which operations are performed in parallel over time. The top row shows the winding operation. The next row shows a series of operations in a movement incorporated into a portable watch body, including magnetic operation testing, acoustic daily rate testing, and water resistance testing operations. The bottom row in the diagram relates to optical testing. The central part of the diagram shows details of the first measurement operation, the acoustic daily rate measurement operation, in which a series of measurements are taken at two different temperatures in various standardized timekeeping positions. [Figure 2] This diagram shows the tick and tack timestamps of the movement, along with the times of the first and last releases, impulses, and drops. [Modes for carrying out the invention]

[0011] The present invention relates to a method for testing the kinematic display chain downstream of the oscillator of a portable watch or portable watch body for the timing of the portable watch or portable watch body, using simultaneous measurement by capturing an optical image of the needle and continuous or nearly continuous acoustic measurement at a series of test stations.

[0012] According to this method, the portable watch or portable watch body is made to keep time continuously for a measurement time TM of at least 24 hours, ideally for several days, depending on the desired measurement accuracy. This can also be achieved by providing the portable watch or portable watch body with an energy source capable of keeping time for at least the measurement time TM, i.e., at least 24 hours, or by providing the test station with a winding device and / or shaking device that winds or shakes the portable watch or portable watch body for at least the measurement time TM of at least 24 hours, or by providing the portable watch or portable watch body with an energy source capable of a specific amount of power reserve and providing the test station with a winding device and / or shaking device that winds or shakes the portable watch or portable watch body to maintain the measurement time TM at least 24 hours.

[0013] At an initial time t0, an initial optical image of at least one hand of the portable watch or portable watch body is taken, with reference to a fixed point on the portable watch or portable watch body, and / or a fixed point on the device that carries the portable watch or portable watch body.

[0014] Immediately after capturing the initial image, a portable watch or the portable watch body is placed in a device equipped with a reference watch and a system for detecting ticks and tacks, and continuous or nearly continuous acoustic measurements of the regulator are performed over the entire period of time t.

[0015] Therefore, between the initial optical image and the final optical image, continuous or nearly continuous acoustic measurements of the oscillator or regulator in the portable watch or the portable watch body can be performed, making it possible to determine the timing deviation.

[0016] At the end of the aforementioned measurement time TM, the timing of the portable watch is acoustically evaluated by counting the number of ticks and tacks relative to the elapsed time.

[0017] Portable watches can be subjected to significant potential stresses that can affect timing, such as dynamic motion, static motion, temperature, and humidity, between two state images.

[0018] Then, at this final time t0+t measured relative to the reference clock, a final optical image of at least one hand of the reference portable clock or portable clock body is captured at a fixed point on the portable clock or portable clock body and / or a fixed point on the instrument. The positions of these hands are determined at the initial time t0 and the final time t0+t by visual recognition means equipped in the test station. The difference between the reference position relative to the reference clock and the actual position of the hands is calculated, and the value of the deviation of the measured state is displayed.

[0019] Thus, thanks to optical measurement, it becomes possible to test the chronometry of the power mechanism + oscillator and the display of a portable watch. On the other hand, acoustic measurement can only test the chronometry of the power mechanism + oscillator of the movement.

[0020] To determine the synchronization of the display, the difference between the timekeeping of a portable timepiece or the portable timepiece body determined by measuring the optical state of the display and the timekeeping of the portable timepiece determined by acoustically measuring the tick and tack sounds continuously or almost continuously is calculated. This difference approaches zero regardless of the performance of the oscillator when there are no display problems in the portable timepiece.

[0021] It can be understood that the present invention relates to the comparison between the time counted by the acoustic regulator and the time counted by the display. The length of this time only affects the accuracy of the desired comparative measurement.

[0022] In an advantageous embodiment of this method, each optical measurement operation is performed by taking a plurality of images and averaging the positions of the hands identified by each of the images to reduce the measurement uncertainty.

[0023] In particular, according to this method, between the initial time and the final time, the portable timepiece or the portable timepiece body is subjected to dynamic spatial movement, winding, standby time in the standard timekeeping position, or other stresses on the regulator and display mechanism in the portable timepiece or the portable timepiece body according to public standards such as ISO 3159 standard, internal standards or other standards.

[0024] In particular, the portable timepiece or the portable timepiece body performs a spatial movement and conducts a timekeeping test in a standardized timekeeping position, and determines the value of the timekeeping deviation in the standardized timekeeping position. Then, the value of the timekeeping deviation and the value of the state deviation are compared with the internal reference to approve or prohibit further manufacture of the portable timepiece or the portable timepiece body.

[0025] In particular, in the standard timekeeping position, an intermediate timekeeping test is performed partially or entirely using instantaneous or continuous acoustic measurements.

[0026] Furthermore, at least one intermediate test is performed at at least one intermediate time between this initial time and this final time. In this intermediate test, at least one intermediate optical image of the hands of the portable clock or the portable clock body is taken based on the fixed point, the positions of the hands at this initial time and this intermediate time are determined by the visual recognition means, the difference between the reference position with respect to the reference clock and the actual position of the hands is calculated, and the value of the state deviation measured at this intermediate time is displayed.

[0027] In particular, between the initial time and the final time, the portable clock or the portable clock body is passed through the furnace under predetermined time, temperature, and humidity conditions.

[0028] In particular, the portable clock or the portable clock body is housed and fixed in a handling box selected to be translucent, and all handling operations from after this initial time to this final time are performed with the portable clock or the portable clock body in the handling box.

[0029] Furthermore, at least one initial image is taken before inserting the portable clock or the portable clock body into the handling box, and at least one final image is taken after taking the portable clock or the portable clock body out of the handling box.

[0030] In one specific embodiment, this test method is used for a mechanical portable clock.

[0031] In the field of timepieces, acoustic measurements are said to be performed in a single shot (generally 40 seconds), but in the case of the present invention, such acoustic measurements are continuous or almost continuous, thereby ensuring that each tick-tock of the portable clock is counted over the entire observation time between two visual state images.

[0032] Specific embodiments of the method according to the present invention will be described in detail below. Note that the present invention is not limited thereto.

[0033] METAS N001 v1.2 is a new requirement for certifying mechanical movements and portable watches capable of withstanding magnetic fields of 1.5T (15000G) and conforms to photoacoustic measurements of portable watches and watch bodies. In particular, it employs techniques based on preparation within acoustic test enclosures that are suitable and versatile for portable watch bodies with a daily deviation of ±50 ms / day, as described in patent documents EP3410234, EP3812847, EP22209439.3, CH001445 / 2022, EP22209441.9 and CH001404 / 2022. These test enclosures are often designed for sets of 10 or more and are optimal for holding portable watches or watch bodies.

[0034] The synchronization of the display is tested by optical measurement of the state of the second hand and / or minute hand. In the "seconds and minutes" variant, the synchronization of the display is tested for approximately 6 days, or at least 120 hours, to minimize measurement uncertainty.

[0035] Figure 1 shows a specific sequence suitable for use in the present invention. The top row shows the following sequence of winding operations R1, ..., Rn for keeping a portable watch in timekeeping mode. That is, winding is performed at the start of each cycle as described in the METAS N001 requirements. Below this is a series of operations, which are magnetic behavior tests, daily rate tests, and water resistance tests, the order and number of which can be changed without departing from the present invention within the scope of the METAS N001 requirements.

[0036] In preparation for testing the portable watch body according to METAS N001 requirements, the portable watch body is placed inside the acoustic test enclosure as described above.

[0037] Preferably, each acoustic test enclosure holds, for example, a set of 10 portable watch cases, and the final timing and condition tests are performed on the entire set.

[0038] The series of operations should preferably be performed automatically and robotically as follows: Each spatial handling operation is applied to the acoustic test enclosure, and each test is performed on the entire enclosure under controlled temperature, controlled humidity, or controlled pressure.

[0039] The first test operation 10 is a chronometer test of the daily rate PJ1, performed with the acoustic test enclosure facing different spatial orientations, in which a microphone, particularly a piezoelectric microphone, is used in contact with the portable watch body inside the acoustic test enclosure to listen for the tick-tock sound of the oscillator of the mechanical portable watch and extract characteristic moments such as release, impulse, and drop, which are common to Swiss pallet escape and coaxial escape, even if the timing does not precisely correspond to contact between the same surfaces. This first test operation 10 is performed in accordance with METAS N001 requirements with respect to temperature and orientation.

[0040] The following will then take place. - Functional testing operations in magnetic fields 20 - A second chronometer test operation 30, similar to the first test operation 10 described above, but in accordance with the requirements of METAS N001 regarding temperature. - Demagnetization Operation 40 - A third chronometer test operation 50, similar to the second chronometer test operation 30 described above, but in accordance with the requirements of METAS N001 regarding temperature. - A fourth chronometer test operation 60, similar to the first test operation 10 described above, but in accordance with the requirements of METAS N001 regarding temperature. - Power reserve test operation 70 (Cycle 7 in METAS N001) - Afterwards, a water resistance test.

[0041] In parallel with the acoustic testing, the row below shows the optical testing. This is useful for checking or disabling display synchronization when handling the portable watch body.

[0042] Display synchronization is tested by capturing optical images of the state of the second and minute hands. Optical hand recognition involves a series of continuous measurements over a 60-second observation period to eliminate artifacts in the optical imaging and determine whether the watch body or the watch itself is ahead or behind between two states. During this period, each acquisition is dated, and a shape matching algorithm is used to retrieve the position and orientation of the watch body or watch, as well as the hands.

[0043] The technology used in acoustic test enclosures, when combined with a portable clock, allows for measurements with an accuracy of ±50 ms / day or ±10 ms / day, provided that the reference clock within each enclosure is calibrated before measurement.

[0044] Paragraphs 0014-0021 and Figures 4-6 of European Patent Document EP3812847 describe in detail an acoustic measurement and processing system and its use. In short, the purpose of this continuous acoustic measurement system is to timestamp the shocks of the movement's oscillator. A control unit processes these timestamps and measures the daily rate of a portable watch body within an acoustic test enclosure.

[0045] Due to the amount of data and energy consumption (processor calculations), the signals corresponding to the portable watch body, specifically 10 units mounted within the acoustic test enclosure, are divided chronologically into multiple signal streams. The number of activated channels and the length of the signal streams are adapted according to the onboard firmware. Each signal stream must last for a minimum of 5 seconds to allow the algorithm to self-construct and detect drops with sufficient accuracy. Detecting the noise threshold and frequency class takes approximately 2 seconds, and accumulating enough data to estimate impulses and drops through overlap takes approximately 3 seconds.

[0046] The onboard algorithm then determines the timestamps for the tick and tack shocks. At the start of each measurement sequence, the algorithm detects the frequency by classifying it into 0.5Hz steps from 2Hz to 5Hz, then detects the noise level of the silent zone to determine the threshold for detecting the release. Tick and tack releases are identified by the threshold being exceeded. Since this information is the modulo of the motion frequency, the first and last releases are retained. Drops and impulses are timestamped by superimposing the signals. Therefore, these timestamps can only be used for the last tick and tack to maximize the amount of data due to the overlap. Figure 2 shows the tick timestamps as solid lines and the tack timestamps as dashed lines, showing only the first tick-tack and last tick-tack for each measurement sequence. Each measurement sequence spans time TH, which is, for example, 10 seconds, and the measurement sequences are spaced apart from each other. For the tick timestamps, t1 corresponds to the first release, t2 to the last release, t3 to the detection of the impulse, and t4 to the detection of the drop. In the case of tack timestamps, t5 corresponds to the first release, t6 to the last release, t7 to impulse detection, and t8 to drop detection.

[0047] Acoustic measurements taken during daytime timing using an acoustic test enclosure are validated by comparative measurements with optical measurements performed in the same manner. A relatively rapid convergence (approximately 24 hours) was observed between the acoustic and optical measurements.

[0048] By using this photoacoustic measurement method in parallel for 120 hours, it becomes possible to achieve an accuracy in display synchronization measurement of the minute hand down to the order of 5 seconds / day and the second hand down to 100 milliseconds, enabling reliable detection of any display malfunctions.

[0049] The general operating procedure involves the following steps, but is not limited to these. - Placement within an acoustic test enclosure - B Winding - C 24 hour standby - D Daily Rate Test 01 - E Winding - F Standard preparations - Functional testing in a G magnetic field - HMS state lasts for 0 hours - I. Placement inside an acoustic test enclosure. - J Daily Rate Test 02 - K demagnetization - L Winding - M 24 hour standby - N Daily Rate Test 03 - O Winding - P 24-hour wait - Q Daily rate test 04 - R Winding - S 48-hour standby - T standard preparation - U MS state lasts for 0 hours - V RM test - W SA exam - X Water resistance test - Y Storage In particular, with the exception of operations G and H, operations A to S are performed on a portable clock body inside an acoustic test enclosure, which is subject to motion provided by a shaker and planned timekeeping inside a furnace. In short, the present invention makes the following technical preparations: prepare a test cycle that meets the requirements of METAS N001, is guaranteed to be completely secure with no possibility of bias in the test due to human intervention, and conforms to the standards already developed for the visual and handling of magnetic field and acoustic test enclosures.

Claims

1. A method for testing the kinematic display chain of a portable clock or portable clock body downstream of an oscillator, simultaneously with testing at a series of test stations, In a series of test stations, the timing of a portable watch or the watch body is measured simultaneously by performing optical measurements of the needle state and continuous or nearly continuous acoustic measurements. The aforementioned portable watch or portable watch body is By providing the portable watch or the portable watch body with an energy source that can operate continuously for at least the measurement time TM, The test station is provided with a winding and / or shaking device that charges the portable watch or the portable watch body for at least the measurement time TM by winding or shaking it. The device will continuously measure for at least 24 hours of measurement time™. method.

2. At an initial time t0, an initial optical image of at least one hand of the portable watch or portable watch body is captured with reference to a fixed point on the portable watch or portable watch body, and / or a fixed point on the device in which the portable watch or portable watch body is housed and fixed. A final optical image of at least one hand of the portable watch or portable watch body is captured at least after the measurement time TM, at the final time measured by the reference watch, with reference to a fixed point on the portable watch or portable watch body and / or a fixed point on the tool. The position of the needle at the initial time and the final time is determined by the visual recognition means provided in the test station. The difference between the reference position on the reference clock and the actual position of the hands is calculated. Displays the deviation value of the measured state. The method according to claim 1.

3. This allows for continuous or nearly continuous acoustic measurement of the oscillator or regulator in the portable watch or the portable watch body between the initial optical image and the final optical image, enabling the determination of timing deviations. The method according to claim 1 or 2.

4. The timing of the portable watch or the portable watch body is acoustically evaluated at the end of the measurement time TM by counting the number of ticks and tacks over the elapsed time. The method according to claim 3.

5. Between the initial time and the final time, the portable watch or the portable watch body is made to perform dynamic motion in dynamic space. This causes the portable watch or the portable watch body to be wound, and / or Conduct a timing test in the standard timing position. The method according to claim 1.

6. Between the initial time and the final time, the portable watch or the portable watch body is stopped in a standardized timing position, and / or other stresses are applied to the regulator and the display mechanism of the portable watch or the portable watch body. The method according to claim 1.

7. The portable watch or the portable watch body is subjected to spatial motion in order to perform a timing test in a standardized timing posture, thereby determining the value of the timing deviation in the standardized timing posture. The deviation value of the aforementioned timing and the deviation value of the aforementioned state are compared with an internal standard, and accordingly, the further manufacture of the portable watch or portable watch body is approved or prohibited. The method according to claim 5 or 6.

8. The timing test is performed using acoustic measurements in the standardized timing position. The method according to claim 5.

9. Between the initial time and the final time, the portable clock or the portable clock body is placed inside the furnace for a predetermined time, under temperature and humidity conditions. The method according to claim 1.

10. The aforementioned portable watch or portable watch body is housed and secured within a light-transmitting handling box. All handling operations during the period after the initial time and up to the final time are performed with the portable watch or the portable watch body inside the handling box. The method according to claim 1.

11. Before inserting the portable watch or the portable watch body into the handling box, take at least one initial image. The at least one final image is taken after removing the portable watch or the portable watch body from the handling box. The method according to claim 10.

12. Used for mechanical portable watches The method according to claim 1.

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