JP3701584B2 - Glass antenna for vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a glass antenna provided on a rear window glass of a vehicle such as an automobile, and more particularly to a glass antenna suitable for receiving radio waves of FM radio broadcast waves.
[0002]
[Prior art]
Conventionally, glass antennas for FM radio broadcast waves and TV broadcast waves are often provided on the rear window glass of a vehicle, and the rear window glass of a vehicle or the like has an antifogging heating in the central region. Often there are streaks. For this reason, when providing an antenna in a rear window glass, it has to be provided in the upper margin part and lower margin part of the said heating wire for anti-fogging.
[0003]
For example, Japanese Patent Application Laid-Open No. 59-198006 discloses a glass antenna for a vehicle in which an antenna wire is provided on a flat glass surface. A T-shaped first antenna comprising a horizontal part and a vertical part; a second antenna for phase adjustment comprising at least one horizontal line connected to one side of the vertical part; and the other antenna of the vertical part A glass antenna for a vehicle is disclosed that includes a third antenna for impedance matching connected to one side and a feed point provided in the third antenna for impedance adjustment.
[0004]
However, the invention described in Japanese Patent Application Laid-Open No. 59-198006 has considerably good reception performance by itself, but is not satisfactory due to fluctuations in the electric field strength of received radio waves depending on the traveling direction of the car. was there.
[0005]
In recent years, as a means for solving such a problem, it is often performed that a car is provided with two antennas and each receives diversity.
[0006]
For example, in the case of a pattern as shown in FIG. 9, a heating conductive wire is disposed at a substantially central portion of a rear window glass for a vehicle, and a main antenna and a lower blank portion are formed in an upper margin of the heating conductive wire. And a horizontal line that is close to the lowest line of the heating conductive line from a feeding point provided near the lower end of one of the bus bars is an intermediate portion of the lowermost line of the heating conductive line. It has been known that the main antenna and the sub-antenna are diversity-received so as to extend to the vicinity.
[0007]
Alternatively, for example, in Japanese Patent Publication No. 1-447922, a main antenna is provided on an upper portion of a glass plate for a rear window of a car, and a plurality of heater wires are separated from the main antenna and separated from the main antenna. A defrosting current heating heater having a bus bar for supplying power to the heater wire, a lead wire connected to a predetermined portion of the lowermost line of the heater, and a feed point for connecting an antenna feeder wire to the lead wire The defogging energizing heater is a sub-antenna having a different directivity from the main antenna, and each of the feeding points has a high internal gain of the received signal received by the main antenna and the sub-antenna. An automotive glass antenna is disclosed in which a radio receiver is connected through a switching circuit that selectively selects one of the two methods. That.
[0008]
[Problems to be solved by the invention]
However, in the case of the pattern shown in FIG. 9, if a wiper attachment hole is provided near the center of the lower margin and a wiper blade is attached, the reception gain of the FM radio broadcast wave band is greatly increased depending on the operating range and stop position. However, there is a problem that it is easily affected by the wiper.
[0009]
On the other hand, in the case of the invention described in Japanese Patent Publication No. 1-447922, in order to make the heating conductive wire provided on the rear window glass function as a sub-antenna, a lead wire 16 is provided at a predetermined position in the lowermost line portion. , And a feed point 18 for connecting the antenna feeder wire to the tip of the lead wire 16 is provided, but when a wiper mounting hole is to be provided in the vicinity of the center of the lower margin portion as described above. The leader line may get in the way. Further, even if the lead wire is provided at a position that does not interfere with the wiper mounting, the lead wire 16 simply connects the conductive wire for heating and the feeding point 18, and the lead wire has a function as an antenna. Since it is not intended to be provided, it cannot be desired to improve the gain beyond the reception performance of the sub-antenna consisting only of the heating conductive wire.
[0010]
[Means for Solving the Problems]
The present invention aims to solve the above problems, that is, when receiving diversity with the main antenna provided in the upper margin of the rear window glass having the heating wire and the sub-antenna provided in the lower margin. Even if a wiper mounting hole is provided in the substantially central part of the blank portion, and the wiper is provided, it is not affected by the receiving gain of the FM radio broadcast wave band of the sub-antenna depending on the operating range and stop position of the wiper blade . The purpose is to obtain a satisfactory reception gain even with a single sub-antenna.
[0011]
That is, the present invention provides a diversity of a main antenna composed of a plurality of conductive wires provided in the upper margin of the heating conductive wire of the vehicle rear window glass and a sub-antenna composed of conductive wires provided in the lower margin. In a glass antenna for a vehicle for receiving FM radio broadcasts ,
The window glass is provided with a wiper mounting hole in the vicinity of the center of the lower margin of the heating conductive wire, and the wiper blade overlaps with the lowermost line of the heating conductive wire at the stop position in the mounting hole. As a conductive wire of the sub-antenna, it is connected via a lead wire connecting a feeding point to one side of a bus bar that connects both ends of a plurality of heating conductive wires arranged substantially parallel in parallel. And a wire extending from the feeding point includes at least a horizontal wire adjacent to a lowermost wire of the heating conductive wire, and at least one horizontal wire is disposed, and the sub antenna includes a wiper blade. Pull out from the bus bar on the side opposite to the movable range side, and make the sub-antenna arrangement range within the range from the bus bar to the middle part of the lowest line of the heating conductive wire. , And a glass antenna for a vehicle, characterized in that to avoid a reduction in the reception gain of FM radio broadcast wave band by the stop position.
[0014]
Alternatively, the present invention is the glass antenna for a vehicle described above, wherein the sub antenna is connected to the vicinity of the lower end portion of the bus bar by a lead line from a feeding point .
[0015]
Alternatively, the glass antenna for a vehicle described above, wherein an auxiliary antenna element having a horizontal line adjacent to the horizontal line of the sub antenna is directly connected to a bus bar connected to the sub antenna.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, in the present invention, a plurality of substantially horizontal conductive wires are arranged in parallel in the central region of a vehicle rear window glass 1 for anti-fogging, and both ends thereof are electrically conductive bus bars 3. The heating conductive wire 2 connected at 3 'is provided, and the upper margin of the heating conductive wire 2 is a combination of a plurality of horizontal and vertical conductive wires. This is a glass antenna for a vehicle in which an antenna 4 is provided and connected to a feeding point 6, and a sub-antenna 5 is provided in a lower margin of the heating conductive wire 2 so that diversity reception is performed by both antennas. .
[0017]
The sub-antenna 5 is connected to the vicinity of the lower end portion of the bus bar 3 on one side of the heating conductive wire 2 via a lead wire 8 connected to the feeding point 7, and the wire extending from the feeding point 7 is connected to the heating wire 7. At least one horizontal line 5a is provided so as to be close to the lowest line 2a of the conductive line 2, and at least one horizontal line 5a is disposed.
[0018]
FIG. 3 shows a sub-antenna in which three horizontal filaments 5a, 5b, and 5c are arranged along a line extending from the feeding point 7 so as to be close to the lowest line 2a of the conductive wire 2 for heating.
[0019]
Further, the horizontal line provided so as to be close to the lowermost line of the heating conductive line 2 from the feeding point 7 is about ½ of the lowermost line 2a and needs to be longer than that. In this case, as shown in FIG. 4, the folded line 5d is folded from the tip of the horizontal line 5a, and the arrangement range of the sub antenna provided in the lower margin is within the range from the bus bar to the substantially middle part of the lowest line. I made it.
[0020]
Further, as shown in FIG. 2, a wiper mounting hole is provided in the vicinity of the center of the lower margin portion adjacent to the lowermost line of the heating conductive wire of the rear window glass of the vehicle, and the wiper blade is shown in the mounting hole. When the sub-antenna 5 is mounted in such a movable range, the arrangement range of the sub-antenna 5 is that of the bus bar located on the opposite side of the main movable range (left half in FIG. 2) of the wiper blade provided in the rear window. It was pulled out from a predetermined position.
[0021]
Note that the main movable range of the wiper also changes depending on the position of the driver's seat of the vehicle, so that the position of the bus bar connected to the sub-antenna can be considered in either case.
[0022]
The sub antenna 5 is connected to the vicinity of the lower end portion of the bus bar 3 by a lead wire 8 from the feeding point 7 in the figure, but may be connected to any position of the bus bar 3 via the lead wire 8. However, since there are many cases where the feeding point 7 is a lower corner in order to enhance the diversity effect, a position near the feeding point 7 is desirable.
[0023]
Further, as shown in FIG. 5, an auxiliary antenna element having a horizontal line 9 close to the horizontal line 5 a of the sub antenna 5 can be directly connected to the bus bar 3 to which the sub antenna 5 is connected.
[0024]
The sub-antenna 5 may be connected to either side of the bus bars 3, 3 ′ provided at both ends of the heating conductive wires 2, 2,.
[0025]
Further, the vertical wire connecting the substantially midpoints of the heating conductive wires composed of a plurality of substantially horizontal wires is a neutral wire, not a conductive wire provided for heating, but a heating conductive wire. Although it is desirable to provide the strip to function as an antenna, this vertical strip may not be provided.
[0026]
Then, the effect | action of this invention is demonstrated.
[0027]
In the present invention, diversity reception is performed by two systems of the FM main antenna 4 connected to the feeding point 6 and the FM sub-antenna 5 connected to the feeding point 7, and both antennas of the two systems are received by diversity reception. However, since the sub-antenna 5 and the heating conductive wire 2 are connected in parallel to the feeding point 7, the heating conductive wire functions as an antenna. In addition, both the radio wave placed on the heating conductive wire and the radio wave placed on the sub-antenna are sent from the feeding point 7 to the receiver, so that the reception performance of the FM radio broadcast receiving band can be greatly improved. It was.
[0028]
By bringing the lowest wire 2a of the heating conductive wire 2 and the horizontal wire 5a of the sub-antenna 5 close to each other, the interaction works and the reception gain of the sub-antenna 5 can be improved.
[0029]
The distance between the lowest line 2a of the heating conductive wire 2 and the horizontal wire 5a of the sub-antenna 5 is preferably about 5 to 10 mm.
[0030]
The length of the sub-antenna of the present invention is preferably in the range of 300 to 500 mm.
[0031]
Further, as shown in FIG. 4, when a folded line 5d folded in a U shape is provided from the front end of the horizontal line 5a of the sub antenna 5 to the vicinity of the front end of the feeding point 7, the frequency characteristics of the received radio wave can be broadened. There is an action that can be made
[0032]
Moreover, the arrangement range of the sub-antenna 5 is set to the range from the bus bar 3 to the substantially middle portion of the lowermost line 2a of the heating conductive wire 2, so that the heating conductive wire on the side opposite to the feeding point 7 is provided. rear wiper 16 is set to the lower margin of 2, it can be avoided reduction of the reception gain by approaching the horizontal strip 5a of the sub-antenna 5.
[0033]
When the three horizontal wires 5a, 5b, and 5c are provided as the sub-antenna from the feeding point 7 and are provided close to each other, the reception sensitivity of the antenna of the sub-antenna 5 is improved by the interaction of the three horizontal wires. Can be made.
[0034]
The interval between the horizontal filaments 5a, 5b and 5c is preferably 5 to 10 mm.
[0035]
Although the auxiliary antenna element 9 and the folded wire 5d are not necessarily required, they effectively work to widen the frequency characteristics and improve the receiving sensitivity by adjusting the impedance.
[0036]
【Example】
Hereinafter, the present invention will be described in detail with reference to the drawings.
[0037]
1 and 2 are a front view of the case where the glass antenna of the present invention is provided in the rear window for an automobile and no wiper is provided (Example 1), and a front view of the case where the wiper is provided (Example 2), respectively. 3 to FIG. 8 are front views showing modified examples thereof, and FIG. 9 is a front view showing a conventional pattern.
[0038]
Examples 1 and 2
As shown in FIGS. 1 and 2, a plurality of substantially horizontal conductive wires are arranged in parallel in the central region of the rear window glass 1 for a vehicle, and both ends thereof are connected by conductive bus bars 3 and 3 ′. The heating conductive wire 2 for preventing fogging is provided. The main antenna 4 and its feeding point 6 are provided in the upper margin of the heating conductive wire 2 for receiving FM radio broadcast waves. Further, a sub-antenna 5 for receiving FM radio broadcast waves and its feeding point 7 are provided in the lower margin of the heating conductive wire 2, and the feeding point 7 is connected to the lower end of the bus bar 3 via the lead wire 8. Connected in the vicinity of the part.
[0039]
The sub-antenna 5 includes a horizontal line 5a along which the line extending from the feeding point 7 is close to the lowest line 2a of the heating conductive line 2, and extends to almost the middle part of the lowest line. It was.
[0040]
Example 1 is a case where the wiper 16 is not attached to the lower margin of the heating conductive wire 2 of the rear window glass 1 as shown in FIG.
[0041]
As shown in FIG. 2, Example 2 is a case where the wiper 16 is attached to the attachment hole 15 provided in the center of the lower margin of the heating conductive wire 2 of the rear window glass 1, and the movable range of the wiper is This is an area mainly in the vicinity of the bus bar 3 'on the opposite side to the bus bar 3 to which the FM sub-antenna 5 is connected, and is indicated by an arrow in FIG.
[0042]
The glass plate 1 has a substantially trapezoidal shape. As an example, the upper side is 1,100 mm, the lower side is 1,200 mm, and the height is 750 mm.
[0043]
The length of the horizontal strip 5a of the sub-antenna 5 extending from the feeding point 7 was set to 450 mm as a reception band mainly including the FM radio broadcast wave band. The distance between the horizontal line 5a and the lowest line of the heating conductive line was 5 mm, and the main antenna 4 was a conventionally known FM radio receiving antenna.
[0044]
Each of these main antenna 4, sub-antenna 5, lead wire 8, and conductive wire for heating 2, 2,..., Feeding point 6, feeding point 7, bus bar 3, 3 'is connected to the surface of glass plate 1 with a conductive paste. It is printed on and fired to form.
[0045]
Further, the main antenna 4 and the sub-antenna 5 are connected to feeder lines from the feeding point 6 and feeding point 7, respectively, and are connected to a receiver (not shown). Further, diversity reception is performed by the two antennas of the FM main antenna 4 connected to the feeding point 6, the sub-antenna 5 connected to the feeding point 7, and the heating conductive wire 2.
[0046]
FIG. 10 is a frequency characteristic diagram when the plate glass thus obtained is attached to the rear window glass of an automobile, and the FM broadcast wave band of 76 MHz to 90 MHz is received from the feeding point 7 by the sub antenna of the present invention. A directional characteristic diagram is shown in FIG.
[0047]
From the frequency characteristic diagram of FIG. 10, it can be seen that the FM sub-antenna has a high reception gain regardless of the presence or absence of the wiper. Further, the average gain difference (dipole antenna ratio) with the standard dipole antenna when the FM broadcast wave is received from the feeding point 7 is as follows.
[0048]
Example 1 (when no wiper is provided as shown in FIG. 1)
FM radio broadcast wave reception band (horizontal polarization): -22.8 dB
Example 2 (when a wiper is provided as shown in FIG. 2)
FM radio broadcast wave reception band (horizontal polarization): -23.2 dB
In addition, the directivity was good regardless of the presence or absence of the wiper.
[0049]
The sub-antenna patterns of Examples 1 and 2 obtained in this manner have good performance in both frequency characteristics and directivity characteristics in the FM radio broadcast reception band regardless of the presence or absence of the wiper. It can be confirmed that the reception is good by the diversity reception.
[0050]
Comparative Example 1
9 is different from the first embodiment shown in FIG. 1 only in that the feeding point 7 of the sub antenna 5 and the bus bar 3 are not connected, and the rest is the same. This is a conventional technique.
[0051]
The plate glass produced in the same manner as in Examples 1 and 2 was mounted on the rear window of the automobile, and the two antennas, the main antenna 4 and the sub-antenna 5, were received with diversity. FIG. 11 shows a frequency characteristic diagram when the FM antenna wave band of 76 MHz to 90 MHz is received from the feeding point 7 and FIG.
[0052]
As can be seen from the frequency characteristic diagram of FIG. 11, the FM sub-antenna has much higher FM broadcast wave band reception performance than the case where the rear wiper is not provided in the lower margin of the heating conductive wire. It is falling.
[0053]
FM band (horizontal polarization) reception gain when no wiper is provided: −23.1 dB
FM gain (horizontal polarization) reception gain when a wiper is provided: -29.7 dB
The sub-antenna pattern of the comparative example obtained in this way showed good reception performance when no wiper was provided in the FM radio broadcast reception band, but received performance when the wiper was provided. It can be seen that is decreasing.
[0054]
Further, as can be seen from FIG. 13, the pattern of the sub-antenna 5 is greatly deteriorated in the directivity characteristics in the FM radio broadcast reception band when the wiper is provided compared to the case where the wiper is not provided. .
[0055]
Modified Example 1
As shown in FIG. 3, the three horizontal lines extending along the horizontal line extending from the feeding point 7 of the sub-antenna of the first embodiment shown in FIG. 1 are close to the lowest line 2 a of the heating conductive line 2. This is a sub-antenna provided with strips 5a, 5b, and 5c.
[0056]
The length of each horizontal filament 5a, 5b, 5c was 450 mm, and the interval was 5 mm.
[0057]
The sub-antenna pattern of the modified example 1 obtained in this way can provide good performance in both frequency characteristics and directivity characteristics in the FM radio broadcast reception band regardless of the presence or absence of a wiper, as in the case of the example 1. It was.
[0058]
Modified Example 2
As shown in FIG. 4, the sub-antenna of Example 1 shown in FIG. 1 is provided with a folded line 5 d that is folded back to the feeding point side from the tip of the horizontal line 5 a that extends to substantially the middle part of the lowest line. .
[0059]
The sub-antenna pattern of the modified example 2 obtained in this way also provides good performance in both frequency characteristics and directivity characteristics in the FM radio broadcast reception band regardless of the presence or absence of a wiper, as in the case of the example 1. It was.
[0060]
Modified Example 3
As shown in FIG. 5, in addition to the sub-antenna of the first embodiment shown in FIG. 1, the horizontal wire 5a extending from the bus bar 3 is close to the lowest line of the heating conductive wire 2, and the horizontal wire 5a This is a sub-antenna in which an auxiliary antenna element 9 is disposed between the lowest lines of the conductive wire 2 for heating.
[0061]
The sub-antenna pattern of the modified example 3 obtained in this way also provides good performance in both frequency characteristics and directivity characteristics in the FM radio broadcast reception band regardless of the presence or absence of a wiper, as in the case of the example 1. It was.
[0062]
Modified example 4
As shown in FIG. 6, the sub-antenna of Example 1 shown in FIG. 1 extends the horizontal line 5 a from the feed point 7 provided near the lower end of the bus bar to the substantially middle part of the lowest line of the heating conductive line 2. In the sub-antenna 5, instead of the lead wire 8 connected to the bus bar 3 from the feeding point 7 shown in FIG. 1, a horizontal line 5a is connected to the feeding point 7 and branched from a position near the feeding point 7. It is connected to the lowermost end of the bus bar 3 through the lead wire 8. Others are the same as those in the first embodiment.
[0063]
The sub-antenna pattern of the modified example 4 obtained in this way also provides good performance in both frequency characteristics and directivity characteristics in the FM radio broadcast reception band regardless of the presence or absence of a wiper, as in the case of the example 1. It was.
[0064]
Modified Example 5
As shown in FIG. 7, it is almost the same as the modified embodiment 3 shown in FIG. 5, but the wiper stop position is on the right side, the sub-antenna 5 is pulled out from the left bus bar 3 ′, and the feeding point 7 of the sub-antenna 5 is The connection position of the leader line 8 connected to the bus bar 3 ′ is set near the intermediate position of the bus bar 3 ′. The third embodiment is the same as the third embodiment except that the wiper attachment position and the attachment position of the sub antenna 5 are interchanged.
[0065]
The sub-antenna pattern of the modified example 5 obtained in this way also provides good performance in both frequency characteristics and directivity characteristics in the FM radio broadcast reception band regardless of the presence or absence of a wiper, as in the case of the example 1. It was.
[0066]
Modified Example 6
As in the embodiment shown in FIG. 8, a plurality of antennas for receiving TV broadcast waves can be added to the sub-antenna 5 of the first embodiment shown in FIG.
[0067]
The antennas 10 and 12 are VHF-Low band antennas, and the antennas 11 and 13 are VHF-High / UHF band antennas. When a TV broadcast wave is to be received, these antennas can be easily added.
[0068]
The sub-antenna pattern of the modified example 6 obtained in this way also provides good performance in both frequency characteristics and directivity characteristics in the FM radio broadcast reception band regardless of the presence or absence of a wiper, as in the case of the first example. It was.
[0069]
【The invention's effect】
When receiving diversity with the main antenna provided in the upper margin of the rear window glass for vehicles having the conductive wire for heating and the sub-antenna provided in the lower margin, a wiper mounting hole is provided at substantially the center of the lower margin. were provided, even if provided with a wiper, never wiper reduces the reception performance of the sub antenna, it is possible to improve improve reception gain in the sub-antenna alone, and the directional characteristics.
[Brief description of the drawings]
FIG. 1 is a front view showing a first embodiment in which a basic antenna pattern of the present invention is provided on a rear window glass for a vehicle.
FIG. 2 is a front view showing a second embodiment when a wiper is installed on the basic antenna pattern of FIG. 1, and a movable range of the wiper.
FIG. 3 is a front view showing a first modified example in which an antenna pattern of the present invention is provided on a rear window glass for a vehicle.
FIG. 4 is a front view showing a second modified example in which the antenna pattern of the present invention is provided on the rear window glass for a vehicle.
FIG. 5 is a front view of a third modified example in which the antenna pattern of the present invention is provided on the rear window glass for a vehicle.
FIG. 6 is a front view showing a fourth modified example in which the antenna pattern of the present invention is provided on the rear window glass for a vehicle.
FIG. 7 is a front view showing a fifth modified example in which the antenna pattern of the present invention is provided on the rear window glass for a vehicle.
FIG. 8 is a front view of a sixth modified example in which the antenna pattern of the present invention is provided on the rear window glass for a vehicle.
FIG. 9 is a front view of a conventional example in which a conventional antenna pattern is provided on a vehicle rear window glass.
FIG. 10 is a frequency characteristic diagram when the radio waves of the FM radio broadcast wave band are received by the antennas according to the first and second embodiments of the present invention shown in FIGS. 1 and 2;
11 is a frequency characteristic diagram when radio waves in the FM radio broadcast wave band are received by the conventional antenna pattern shown in FIG. 9;
12 is a directional characteristic diagram when radio waves in the FM radio broadcast wave band are received by the antenna according to the first and second embodiments of the present invention shown in FIGS. 1 and 2. FIG.
13 is a directional characteristic diagram when the radio wave of the FM radio broadcast wave band is received by the conventional antenna pattern shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Glass plate 2 Heating conductive wire 3, 3 'Bus bar 4 Main antenna 5 Sub antenna 5a Horizontal wire 6, 7 Feeding point 8 Lead wire 9 Auxiliary antenna elements 10-13 TV antenna 15 Wiper attachment hole 16 Wiper

Claims (3)

FM that is configured to receive diversity reception of a main antenna made of a plurality of conductive wires provided in an upper margin of a heating conductive wire in a rear window glass for a vehicle and a sub-antenna made of conductive wires provided in a lower margin. In a glass antenna for a vehicle for receiving radio broadcasts ,
The window glass is provided with a wiper mounting hole in the vicinity of the center of the lower margin of the heating conductive wire, and the wiper blade overlaps with the lowermost line of the heating conductive wire at the stop position in the mounting hole. As a conductive wire of the sub-antenna, it is connected via a lead wire connecting a feeding point to one side of a bus bar connecting both ends of a plurality of conductive wires for heating arranged substantially horizontally in parallel. And the wire extending from the feeding point includes at least a horizontal wire adjacent to the lowest line of the heating conductive wire, and at least one horizontal wire is disposed, and the sub antenna includes a wiper blade. Pull out from the bus bar on the side opposite to the movable range side, and set the range of the sub-antenna within the range from the bus bar to the middle of the lowest line of the heating conductive wire. , And the glass antenna for a vehicle, characterized in that to avoid a reduction in the reception gain of FM radio broadcast wave band by the stop position. 2. The glass antenna for a vehicle according to claim 1, wherein the sub antenna is connected in the vicinity of a lower end portion of the bus bar by a lead line from a feeding point . The glass antenna for a vehicle according to claim 1 or 2 , wherein an auxiliary antenna element having a horizontal line adjacent to the horizontal line of the sub antenna is directly connected to a bus bar connected to the sub antenna.

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