JP6423744B2 - Satellite radio clock - Google Patents

Description

  The present invention relates to a satellite radio timepiece.

  A satellite timepiece that receives a satellite radio wave including time information and corrects the time is known. A satellite radio timepiece may receive satellite radio waves with a patch antenna.

  In the following Patent Document 1, in plan view, a battery and a patch antenna are arranged side by side on a central axis, a decoding circuit is arranged on one side of the central axis, and a controller is arranged on the other side of the central axis. A wristwatch is disclosed. This document describes that a metal member having a large volume, such as a crown, is disposed far from the patch antenna to prevent a decrease in reception performance of the patch antenna.

JP 2011-208944 A

  A patch antenna is an antenna suitable for receiving radio waves in a high frequency band transmitted from a GPS (Global Positioning System) satellite or the like, but when a conductive member or the like is disposed around the patch antenna, Satellite radio waves may be reflected or absorbed, and the reception performance may not be fully demonstrated.

  Here, logotypes representing product names, company names, etc. may be made of conductive materials from the standpoint of decorativeness, and it is difficult to place them near the patch antenna due to concerns about the impact on reception performance. It was.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a satellite radio timepiece in which design restrictions are reduced when a logotype formed of a conductive material is disposed.

  The invention disclosed in the present application in order to solve the above problems has various aspects, and the outline of typical ones of these aspects is as follows.

  (1) A satellite radio-controlled timepiece is arranged on the patch antenna receiving surface side that receives satellite radio waves, and overlaps at least the electrode surface of the patch antenna in a plan view, and at least a part thereof is made of a conductive material. A logo portion formed, and the conductive portion of the logo type formed of a conductive material does not overlap with the periphery of the electrode surface, or the length of the periphery of the overlapping portion. The ratio to is 5% or less.

  (2) In (1), the logotype includes a non-conductive portion formed of a non-conductive material, and the non-conductive portion overlaps with the periphery in a plan view.

  (3) In (1) or (2), the portion overlapping with the electrode surface in plan view is disposed in a region where at least one of the electric field strength and magnetic field strength on the electrode surface is smaller than the maximum value by 3 dB or more. Satellite radio clock.

  (4) The satellite radio-controlled timepiece according to any one of (1) to (3), wherein an area of a minimum convex figure that envelops the conductive portion in a plan view is 70% or less with respect to an area of the electrode surface.

  (5) A satellite radio-controlled timepiece according to (1), further including a solar cell, wherein the logotype is arranged at a position not overlapping the solar cell in plan view.

  According to the above aspect (1) of the present invention, it is possible to obtain a satellite radio-controlled timepiece in which design restrictions are reduced when a logotype formed of a conductive material is disposed.

  In addition, according to the above aspect (2) of the present invention, a satellite radio-controlled timepiece can be obtained in which a logotype having a size approximately equal to or larger than the peripheral length of the electrode surface of the patch antenna can be arranged.

  In addition, according to the above aspect (3) of the present invention, a satellite radio-controlled timepiece having good reception sensitivity can be obtained even when a logotype formed of a conductive material is disposed.

  Further, according to the above aspect (4) of the present invention, a satellite radio timepiece with reduced reflection and shielding of satellite radio waves can be obtained even when a logotype formed of a conductive material is disposed.

  In addition, according to the above aspect (5) of the present invention, a satellite radio timepiece in which a decrease in power generation amount is prevented even when a logotype is arranged is obtained.

It is a top view which shows an example of the external appearance of the satellite radio-controlled wristwatch which concerns on embodiment of this invention. It is a perspective view of the patch antenna built in the satellite radio-controlled wristwatch according to the embodiment of the present invention. It is a top view which shows arrangement | positioning of the logotype in the 1st modification of the satellite radio-controlled wristwatch which concerns on embodiment of this invention. It is a top view which shows arrangement | positioning of the logotype in the 2nd modification of the satellite radio-controlled wristwatch which concerns on embodiment of this invention. It is a top view which shows the electric field strength in the electrode surface of the patch antenna built in the satellite radio-controlled wristwatch concerning the embodiment of the present invention. It is a top view which shows the magnetic field intensity in the electrode surface of the patch antenna built in the satellite radio-controlled wristwatch concerning the embodiment of the present invention. It is a top view which shows the minimum convex figure which envelops the logotype of the satellite radio-controlled wristwatch which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view showing an example of the appearance of a satellite radio-controlled wristwatch 1 according to an embodiment of the present invention. In the figure, a dial 12 arranged in a case 10 which is an exterior (watch case) of the satellite radio-controlled wristwatch 1, an hour hand 22, a minute hand 20 and a second hand 24 which are hands indicating time, and a patch antenna 30 are shown. Has been. On the dial plate 12, a logo type 26, which is made of a conductive material and has the letters “CITIZEN”, is formed at a position overlapping the patch antenna 30 in plan view. Further, on the side of the trunk 10, a crown 14, a first push button 16, and a second push button 18, which are operation units for a user of the satellite radio-controlled wristwatch 1 to perform various operations, are disposed.

  The satellite radio-controlled wristwatch 1 is provided with a windshield formed of a transparent material such as glass so as to cover the dial 12. A back cover is attached to the body 10 on the opposite side of the windshield. In the present specification, hereinafter, the direction in which the windshield of the satellite radio-controlled wristwatch 1 is disposed (front side in FIG. 1) is referred to as the front side, and the direction in which the back cover is disposed (back direction in FIG. 1) is referred to as the back side.

  A solar cell 42 is disposed on the back side of the dial 12 and power is generated by light incident from the front side. Therefore, the dial 12 is made of a material that transmits light to some extent. Here, the logotype 26 is disposed at a position that does not overlap with the solar cell 42 in plan view. Thereby, even if it is a case where the logotype 26 is arrange | positioned, the fall of electric power generation amount is prevented. Further, the front surface of the patch antenna 30 is a receiving surface that receives radio waves from a satellite. The receiving surface of the patch antenna 30, the light receiving surface of the solar cell 42, and the dial 12 are provided in parallel to each other, and all face the front side.

  In this specification, the term satellite radio wave wristwatch refers to a wristwatch that receives a satellite signal from a satellite that transmits information (time information) related to date and time, such as a GPS (Global Positioning System) satellite. In addition, it is used to indicate a wristwatch having a function of correcting the internal time, which is time information held in the wristwatch, based on the time information included therein. However, the present invention is not limited to the satellite radio-controlled wristwatch, but can be applied to a small timepiece that is not a wristwatch, such as a pocket watch. The satellite radio wave wristwatch may also receive orbit information included in the satellite signal. The satellite that transmits the satellite signal received by the satellite radio-controlled wristwatch may be a satellite that is operated in addition to the GPS satellite or that is planned to be used in the future, such as Glonas, Galileo, and Compass (Hokuto). Good.

  A satellite radio wave transmitted from a GPS satellite is a radio wave obtained by modulating a carrier wave (L1 band radio wave) having a frequency of about 1.6 GHz by phase shift modulation. The signal encoded by the satellite radio wave is a signal obtained by superimposing a pseudo random number (PRN) unique to each GPS satellite and a satellite signal including time information. The satellite radio wave wristwatch 1 receives a plurality of satellite radio waves transmitted from a plurality of satellites and determines which satellite PRN has a large correlation, so that each of the received satellite radio waves It is discriminated whether it is transmitted from the satellite. In this specification, such a satellite discrimination process is referred to as satellite radio wave tracking. The satellite signal includes time information. The time information includes the TOW (Time Of Week) indicating the current time starting from the beginning of the week (Sunday 0:00 am) and the current time counted from a predetermined reference time. And week number WN indicating the number of the week. Therefore, depending on the case, the satellite radio-controlled wristwatch 1 may receive only the TOW or may receive the TOW and the week number WN together. Further, since the GPS time has a deviation due to leap seconds with respect to the coordinated universal time, the GPS satellites also transmit leap second information for correcting this deviation. Therefore, the satellite radio wave wristwatch 1 also receives leap second information from the GPS satellite. Further, the satellite signal includes orbit information. The orbit information is composed of almanac, which is the orbit information of all satellites, and ephemeris, which is the orbit information of each satellite. The satellite radio wave watch 1 calculates distances from a plurality of GPS satellites orbiting the sky based on the received orbit information, calculates the latitude, longitude and altitude of the current position, and determines the time zone of the current position. Good.

  The design of the satellite radio-controlled wristwatch 1 shown in FIG. 1 is an example. In addition to those shown here, for example, the barrel 10 may be square instead of round, and the presence, number, and arrangement of the crown 14, the first push button 16, and the second push button 18 are arbitrary. . In the present embodiment, the hands are three hands of the hour hand 22, the minute hand 20, and the second hand 24. However, the present invention is not limited to this, and the second hand 24 may be omitted, or the day of the week, the time zone, and whether there is summer time. , Radio wave reception status, remaining battery level, pointers for various displays, date display, and the like may be added.

  FIG. 2 is a perspective view of the patch antenna 30 built in the satellite radio-controlled wristwatch 1 according to the embodiment of the present invention. The patch antenna 30 in the present embodiment is a so-called surface mount type, and as shown in the figure, a rectangular electrode surface 38 is formed on the upper surface of a flat rectangular parallelepiped body 36 formed of a suitable dielectric such as ceramics. In addition, one power supply electrode 32 and seven ground electrodes 34 are formed on the lower surface of the body 36. The feeding electrode 32 is continuously connected to the strip electrode 33 provided on the side surface of the body 36. The strip electrode 33 is close to the electrode surface 38 and capacitively coupled. Therefore, the satellite radio wave received by the electrode surface 38 is transmitted to the strip electrode 33 through such capacitive coupling, and can be taken out from the feeding electrode 32. On the lower surface of the body 36, a solid electrode that covers almost the entire lower surface is formed as a counter electrode for the electrode surface 38, and an insulating film having a pattern that exposes a part of the solid electrode is provided. The seven ground electrodes 34 are solid electrodes exposed in a region where the insulating film is not provided, and are electrically connected to each other.

  In the satellite radio-controlled wristwatch 1 according to the present embodiment, the logotype 26 is disposed on the receiving surface side of the patch antenna 30 and overlaps at least the electrode surface 38 of the patch antenna 30 in a plan view, and at least a part is made of a conductive material. It is formed. The logo type 26 is provided so that a conductive portion formed of a conductive material does not overlap with the periphery of the electrode surface 38. Specifically, the logo type 26 in the present embodiment is a character that is entirely formed of a metal thin film and has a decorative property due to metallic luster. That is, the logo type 26 in the present embodiment is a conductive portion as a whole. The logotype 26 is not limited to characters, and may be a graphic or a combination of a character and a graphic. In addition, the logotype 26 in the present embodiment is disposed at a position where the entire logotype 26 overlaps with the electrode surface 38 in a plan view and does not overlap with the periphery of the electrode surface 38.

  Conventionally, a logotype formed of a conductive material may be provided at a position away from the receiving surface of the patch antenna so as not to prevent the reception of satellite radio waves by the patch antenna. For this reason, there were design restrictions when placing logotypes. However, as will be described later, the portion of the electrode surface of the patch antenna that greatly contributes to the reception of satellite radio waves is the peripheral portion of the electrode surface. Therefore, in the logotype 26 in the present embodiment, the antenna radio wave reception sensitivity is improved by arranging the logotype 26 at a position that overlaps with the electrode surface 38 in a plan view and does not overlap with the periphery of the electrode surface 38. Design constraints are reduced without substantial degradation.

  FIG. 3 is a plan view showing an arrangement of the logotype 26 in the first modification of the satellite radio-controlled wristwatch 1 according to the embodiment of the present invention. The logo type 26 in the present modification is “-CITIZEN-” characters, and is different from the embodiment shown in FIG. 1 in that a hyphen is added before and after the character portion “CITIZEN”. . The configuration of the satellite radio-controlled wristwatch 1 other than the logo type 26 is the same between the present modification and the embodiment shown in FIG.

  The logotype 26 in the present modification is disposed on the receiving surface side of the patch antenna 30 and overlaps at least the electrode surface 38 of the patch antenna 30 in a plan view, and at least a part thereof is formed of a conductive material. Further, in the logo type 26 in this modification, the ratio of the length of the portion overlapping the electrode surface 38 of the patch antenna 30 in plan view to the length of the peripheral edge of the electrode surface 38 is 5% or less. Specifically, the logo type 26 in the present embodiment is entirely formed of a metal thin film, the length of the portion overlapping the electrode surface 38 of the patch antenna 30 in a plan view is L1, and the electrode surface 38 of the patch antenna 30 is If the length is L and the electrode surface 38 is substantially square, the above condition can be expressed as 2L1 / 4L ≦ 5%.

  According to the satellite radio-controlled wristwatch 1 according to this modification, even when the logotype is formed of a conductive material, a part of the logotype is allowed to overlap the periphery of the electrode surface of the patch antenna in plan view. This further reduces design constraints when placing logotypes. As will be described later, the reception sensitivity at the time of transmission / reception by the patch antenna mostly contributes in the vicinity of the periphery of the electrode surface 38, and it is desirable that the portion overlapping the periphery of the conductive portion of the logo type 26 is as small as possible. However, according to the study of the inventors of the present invention, the length of the portion overlapping the electrode surface of the patch antenna in the plan view in the logo type conductive portion is 5% or less of the peripheral length of the electrode surface. If so, the reception sensitivity of satellite radio waves is not substantially lowered, and both good reception sensitivity and logo type design can be achieved.

  FIG. 4 is a plan view showing an arrangement of the logotype 26 in the second modification of the satellite radio-controlled wristwatch 1 according to the embodiment of the present invention. The logotype in this modification is the letter “CITIZEN”, the letter “C” made of a non-conductive material, the first non-conductive part 26a that is a letter “C”, and the letter “ITIZE” made of a conductive material. A certain conductive portion 26b and a second nonconductive portion 26c, which is a letter “N” made of a nonconductive material, are formed. The logotype in the present modification is different from the embodiment shown in FIG. 1 in that the first nonconductive portion 26a and the second nonconductive portion 26c are included. Moreover, the logotype in this modification is large compared with the case of embodiment shown in FIG. The configuration of the satellite radio-controlled wristwatch 1 other than the logo type is the same between the present modification and the embodiment shown in FIG.

  Among the logotypes in this modification, the first non-conductive portion 26a and the second non-conductive portion 26c overlap with the periphery of the electrode surface 38 of the patch antenna 30 in plan view. On the other hand, the conductive portion 26 b is provided so as not to overlap with the periphery of the electrode surface 38. Since the first non-conductive portion 26a and the second non-conductive portion 26c are made of a non-conductive material, the patch antenna 30 hardly affects the reception of satellite radio waves regardless of the position.

  The satellite radio-controlled wristwatch 1 according to the present modification includes the first non-conductive portion 26a and the second non-conductive portion 26c, so that the logo type design freedom is not reduced without reducing the reception sensitivity of the satellite radio wave by the patch antenna. The degree can be improved. According to the logotype in the first modification, it was allowed to superimpose a part of the logotype formed of a conductive material on the periphery of the electrode surface. Logotypes that are as large as or larger than the peripheral length of the surface can be placed. More specifically, a large logo type 26 that overlaps the periphery of the electrode surface 38 can be disposed over a length exceeding 5% of the periphery of the electrode surface 38 of the patch antenna.

  FIG. 5 is a plan view showing the electric field strength on the electrode surface 38 of the patch antenna 30 built in the satellite radio-controlled wristwatch 1 according to the embodiment of the present invention. When receiving the satellite radio wave, an electric field corresponding to the satellite radio wave is generated on the electrode surface 38 of the patch antenna 30. The electric field is strongest at the corners of the electrode surface 38. FIG. 5 shows the electric field strength at the electrode surface 38 in decibels with reference to the maximum value at the corner. The two-dot chain line shown in the figure is an isointensity line connecting points having the same electric field strength.

  The electric field strength decreases by -3 db in the vicinity of the four corners of the electrode surface 38. That is, the intensity is halved compared to the maximum value. In the same figure, a -9 dB isointensity line that exists across the electrode surface 38 is shown. Further, in the same figure, an isointensity line of −27 dB that exists across the electrode surface 38 is shown.

  Of the conductive portion of the logotype 26 in the present embodiment, the portion overlapping the electrode surface 38 in plan view is disposed in a region where the electric field strength on the electrode surface 38 is 3 dB or more smaller than the maximum value. Furthermore, it is desirable that the conductive portion of the logo type 26 that overlaps the electrode surface 38 in plan view is disposed in a region where the electric field strength on the electrode surface 38 is 9 dB or more smaller than the maximum value. The entire logotype 26 in the present embodiment is a conductive portion, and is an area that overlaps with the electrode surface 38 in a plan view, and the entire area is an area where the electric field strength on the electrode surface 38 is 9 dB or more smaller than the maximum value. Be placed.

  According to the satellite radio-controlled wristwatch 1 according to the present embodiment, even when a logotype formed of a conductive material is disposed, the reception sensitivity is kept good. In the present embodiment, the logo-type conductive portion is arranged in a region where the electric field strength on the electrode surface is 9 dB or more smaller than the maximum value. Therefore, the intensity of the electric field generated in the region overlapping with the conductive portion is only 1/95 or less of the maximum value, and there is almost no influence on the reception of satellite radio waves by the patch antenna.

  FIG. 6 is a plan view showing the magnetic field strength on the electrode surface 38 of the patch antenna 30 built in the satellite radio-controlled wristwatch 1 according to the embodiment of the present invention. When receiving the satellite radio wave, a magnetic field corresponding to the satellite radio wave is generated on the electrode surface 38 of the patch antenna 30. The magnetic field has the strongest intensity at the central portion of the periphery of the electrode surface 38. FIG. 6 illustrates the intensity of the magnetic field on the electrode surface 38 in units of decibels with the maximum value at the central portion of the periphery as a reference. The two-dot chain line shown in the figure is an isointensity line connecting points having the same magnetic field intensity.

  The strength of the magnetic field decreases by −3 db in the vicinity of the two central portions on the periphery of the electrode surface 38. That is, the intensity is halved compared to the maximum value. In the same figure, a -9 dB isointensity line that exists across the electrode surface 38 is shown. Further, in the same figure, an isointensity line of −27 dB that exists across the electrode surface 38 is shown.

  Of the conductive portion of the logotype 26 in the present embodiment, the portion overlapping the electrode surface 38 in plan view is disposed in a region where the magnetic field strength on the electrode surface 38 is 3 dB or more smaller than the maximum value. Furthermore, it is desirable that the conductive portion of the logo type 26 that overlaps the electrode surface 38 in plan view is disposed in a region where the magnetic field strength on the electrode surface 38 is 9 dB or more smaller than the maximum value. The entire logotype 26 in the present embodiment is a conductive portion, and is an area that overlaps with the electrode surface 38 in a plan view, and is entirely in an area where the magnetic field strength on the electrode surface 38 is 9 dB or more smaller than the maximum value. Be placed.

  According to the satellite radio-controlled wristwatch 1 according to the present embodiment, even when a logotype formed of a conductive material is disposed, the reception sensitivity is kept good. In the present embodiment, the logo-type conductive portion is disposed in a region where the magnetic field strength on the electrode surface is 9 dB or more smaller than the maximum value. Therefore, the intensity of the magnetic field generated in the region overlapping the conductive portion is only 1/95 or less of the maximum value, and there is almost no influence on the reception of satellite radio waves by the patch antenna. As apparent from FIGS. 5 and 6, in the satellite radio-controlled wristwatch 1 according to the present embodiment, the conductive portion of the logo type 26 has at least a maximum value relative to the electric field strength and magnetic field strength of the electrode surface 38, respectively. It is arranged in a region where it is reduced by 3 dB, preferably 9 dB or more. As a result, the influence on the reception of satellite radio waves is extremely small.

  FIG. 7 is a plan view showing the minimum convex figure 40 enveloping the logotype 26 of the satellite radio-controlled wristwatch 1 according to the embodiment of the present invention. The minimum convex figure 40 that envelops the logotype 26 is a convex figure that has the smallest area among the figures that enclose the logotype 26 that is the character of “CITIZEN”. In the present specification, a convex figure means a plane figure in which a straight line connecting any two points on the figure fits inside the figure.

  The logo type 26 in the present embodiment is entirely formed of a conductive material, and the area of the minimum convex figure 40 enveloping the logo type 26 is 70% or less with respect to the area of the electrode surface 38. Further, it is desirable that the area of the minimum convex figure 40 enveloping the logo type 26 is 50% or less with respect to the area of the electrode surface 38. The area of the minimum convex figure 40 enveloping the logotype 26 in the present embodiment is approximately 15% with respect to the area of the electrode surface 38.

  As described above, the contribution in the vicinity of the periphery of the electrode surface 38 is dominant in the reception sensitivity at the time of transmission / reception by the patch antenna, but it is not expected that a very large conductive member is disposed immediately above the electrode surface 38. There are concerns about problems such as reflection and interference of non-satellite radio waves and capacitive coupling between the conductive member and the electrode surface 38. In this regard, according to the examination of the inventors of the present invention, it has been found that even when a logotype formed of a conductive material is disposed, reflection and shielding of satellite radio waves are reduced. That is, if the area of the minimum convex figure that envelops the logotype is 70% or less compared to the area of the electrode surface, the above-described problem is difficult to occur, and the satellite antenna can be satisfactorily received by the patch antenna. .

  The following is a guideline for designing the satellite radio-controlled wristwatch 1 including the embodiment of the present invention described above and its modifications. It is not always necessary to set all of these guidelines, and they may be adopted as appropriate according to the required reception performance.

  The first pointer is disposed on the receiving surface side of the patch antenna that receives satellite radio waves, and is at least partially overlapped with the electrode surface of the patch antenna in plan view, and at least a part thereof is formed of a conductive material. The conductive portion formed of a conductive material in the logo type does not overlap with the periphery of the electrode surface, or the ratio of the length of the overlapping portion to the length of the periphery Is to design the satellite radio timepiece so that it is 5% or less.

  The second pointer is a satellite radio timepiece designed according to the first pointer, wherein the logo type includes a non-conductive portion formed of a non-conductive material, and the non-conductive portion includes the peripheral edge in a plan view. It is designed to overlap.

  In a satellite radio timepiece designed according to the first or second pointer, the third pointer is a portion of the conductive portion that overlaps the electrode surface in a plan view, at least of the electric field strength and magnetic field strength on the electrode surface. One of them is designed to be arranged in a region smaller than the maximum value by 3 dB or more.

  The fourth pointer is a satellite radio timepiece designed according to any one of the first to third pointers, and the area of the minimum convex figure that envelops the conductive portion in plan view is 70% of the area of the electrode surface. Design to be as follows.

  The fifth pointer is a satellite radio-controlled timepiece designed according to the first pointer and further includes a solar cell, and the logotype is designed to be arranged at a position not overlapping the solar cell in plan view. That is.

  As mentioned above, although embodiment concerning this invention was described, the specific structure shown in this embodiment was shown as an example, and it is not intending limiting the technical scope of this invention to this. Those skilled in the art may appropriately modify these disclosed embodiments, and it should be understood that the technical scope of the invention disclosed herein includes such modifications.

  1 Satellite radio watch, 10 trunk, 12 dial, 14 crown, 16 first push button, 18 second push button, 20 minute hand, 22 hour hand, 24 second hand, 26 logo type, 26a first non-conductive part, 26b conductive part 26c 2nd non-conductive part, 30 patch antenna, 32 feeding electrode, 33 strip electrode, 34 ground electrode, 36 body, 38 electrode surface, 40 envelope shape, 42 solar cell.

Claims (5)

A patch antenna that receives satellite radio waves,
The patch antenna is disposed on the receiving surface side of the patch antenna, and in a plan view, at least partially overlaps with the electrode surface of the patch antenna, and has a logo type formed at least partially of a conductive material,
Among the logotypes, a satellite radio timepiece in which a conductive portion formed of a conductive material does not overlap with the periphery of the electrode surface, or the ratio of the length of the overlapping portion to the length of the periphery is 5% or less. . The logotype includes a non-conductive portion formed of a non-conductive material,
The satellite radio timepiece according to claim 1, wherein the non-conductive portion overlaps with the peripheral edge in a plan view.   The part which overlaps with the said electrode surface in planar view among the said electroconductive parts is arrange | positioned in the area | region in which at least any one of the electric field strength and magnetic field intensity in the said electrode surface becomes 3 dB or more smaller than the maximum value. The satellite radio clock described.   4. The satellite radio timepiece according to claim 1, wherein an area of a minimum convex figure enveloping the conductive portion in a plan view is 70% or less with respect to an area of the electrode surface. 5. A solar cell,
The satellite radio-controlled timepiece according to claim 1, wherein the logotype is arranged at a position where the logotype does not overlap with the solar battery in plan view.

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