Method of measuring the accuracy of a mechanical watch

Patent metadata

Field	Value
Publication number	US-9348317-B2
Application number	US-201113885558-A
Country	US
Kind code	B2
Filing date	Nov 22, 2011
Priority date	Nov 26, 2010
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

A method of measuring accuracy of a watch including a visual display device, including: storing a first instant, at which the display is in a first display position corresponding to a first image, with a corresponding time reference source; determining a first display value for the first image and stored in a storage in correlation with the first instant; storing, after a determined time interval, a second instant, at which the display is in a second display position corresponding to a second image, with the corresponding source; determining a second display value for the second image and stored in the storage in correlation with the second instant; and calculating displaying on a viewing device the variation in rate of the display.

First claim

The invention claimed is:

1. A method of measuring accuracy of at least one timepiece that is a mechanical watch, including at least one visual display device, and where one of said at least one visual display device of said timepiece is selected as an experimental display, the method comprising:—a first measured instant, at which said experimental display is in a first display position corresponding to a first image generated by an image generator coupled to an internal or external time reference source, said first image being supplied at a request of a user, is stored with said corresponding internal or external time reference source, said first display position is synchronized, in optical comparison to a time display position of said timepiece with said first image, the user alters the position of said first image as desired to synchronize said first image with a real timepiece display, a first display value, corresponding to said first image, is determined and said first display value is stored in a storage device in correlation with said first instant;—after a determined time interval following said first instant, a second measured instant, at which said experimental display is in a second display position corresponding to a second image, said second image being generated by said same image generator, said second image being supplied at the request of the user, is stored with said corresponding time reference source said second display position is synchronized, in optical comparison to the time display position of said timepiece with said second image, the user alters the position of said second image as desired to synchronize said second image with said real timepiece display a second display value, corresponding to said second image, is determined and said second display value is stored in said storage device in correlation with said second instant;—a time difference displayed between said second display value and said first display value is calculated; and—a variation in rate of said experimental display is calculated, and said variation in rate is displayed on a viewing device.

2. A method of measuring the accuracy of at least one timepiece that is a mechanical watch, including at least one visual display device, where one of said at least one visual display device of said timepiece is selected as an experimental display, the method comprising:—a first photographed image of said experimental display is shot at a first instant with a camera coupled to an internal or external time reference source and provided with a storage device to store the first photographed image resulting from a first shot and a time reference point of said first instant provided by said time reference source, at which a first measured instant said experimental display is in a first display position corresponding to said first photographed image, is stored with a corresponding internal or external time reference source, and the time reference point of said first instant provided by said time reference source is stored in said storage device;—a user superposes a first built image generated by an image generator on the image of said first photograph, said first built image being built by the user, who changes a position thereof as desired to make said first built image similar to said first photographed image, a first display value corresponding to said first built image is determined and the first display value is stored in said storage device in correlation with said first instant;—after a determined time interval following said first shot, a second photographed image is shot at a second instant on the same said experimental display with the same camera coupled to the same time reference source and provided with the same storage device to store the second photographed image resulting from a second shot and a time reference point of said second instant provided by said time reference source, at which a second measured instant said experimental display is in a second display position corresponding to said second photographed image, is stored with a corresponding internal or external time reference source, and the time reference point of said second instant provided by said time reference source is stored in said storage device;—the user superposes a second built image generated by said image generator on the said second photographed image, said second built image being built by the user, who alters a position thereof as desired to make said second built image similar to said second photographed image a second display value corresponding to said second built image is determined and said second display value is stored in said storage device in correlation with said second instant a time difference displayed between said second display value and said first display value is calculated;—a variation in rate of said experimental display is calculated, and said variation in rate is displayed on a viewing device.

3. The measuring method according to claim 1 , wherein:—one of said at least one visual display device of said timepiece is selected as the experimental display;—a first photograph is shot at a first instant with a camera, coupled to the internal or external time reference source and provided with the storage device to store a first image resulting from a first shot, which is processed, using an image analyzer to determine a first display value stored in the storage device in correlation with a time reference point of said first instant provided by said time reference source;—after a determined time interval following said first shot, a second photograph is shot at a second instant on the same experimental display with the same camera coupled to the same time reference source and provided with the same storage device to store a second image resulting from a second shot which is processed, using said image analyzer, to determine a second display value stored in the storage device in correlation with a time reference point of said second instant provided by said time reference source;—a time difference displayed between said second display value and said first display value is calculated;—and a variation in rate of said experimental display is calculated, and said variation in rate is displayed on the viewing device.

4. The measuring method according to claim 1 , wherein:—a series of cycles is performed of storing the first display value stored in the storage device in correlation with said first instant, and the second display value stored in said storage device in correlation with said second instant, and the results of calculations of the displayed difference, real difference, variation in rate and accuracy are stored, and a mean accuracy is calculated.

5. The measuring method according to claim 2 , wherein:—a series of cycles is performed of storing the first display value stored in the storage device in correlation with said first instant, and a second display value stored in said storage device in correlation with said second instant, and results of calculations of the displayed difference, real difference, variation in rate and accuracy are stored, and a mean accuracy is calculated.

6. The measuring method according to claim 3 , wherein:—a series of cycles is performed of storing the first display value stored in the storage device in correlation with said first instant, and the second display value stored in said storage device in correlation with said second instant, and results of calculations of the displayed difference, real difference, variation in rate and accuracy are stored, and a mean accuracy is calculated.

7. The measuring method according to claim 1 , wherein:—the method is applied to a plurality of timepieces, wherein each cycle of storing the first display value stored in the storage device in correlation with sai

Assignees

• Willemin Michel
• Decosterd Cedric
• Hessler Thierry
• Conus Thierry
• Swatch Group Res & Dev Ltd

Inventors

• Willemin Michel
• Decosterd Cedric
• Hessler Thierry
• Conus Thierry

Classifications

• G04D7/004 Primary

  Optical measuring and testing apparatus · CPC title

• G04D7/12

  Timing devices for clocks or watches for comparing the rate of the oscillating member with a standard {(supporting devices for clocks with built-in recording apparatus G04D1/063; measuring short time intervals G04F10/00; frequency measuring in general H04B, G01R)} · CPC title