JP5204735B2 - Capacitive touch pad input device and device equipped with the same - Google Patents

Description

  The present invention relates to a capacitive touch pad input device capable of detecting a position touched by an object and a device equipped with the same.

This type of touchpad input device includes a resin film substrate on the back side of the touch surface. The film substrate has drive electrodes and detection electrodes laid side by side, and these electrodes are electrically connected to the printed circuit board.
When an object (for example, a dielectric such as a finger) touches the touch surface, the capacitance between the drive electrode and the detection electrode changes, and an output corresponding to the change in the capacitance is obtained from the detection electrode. Thereby, the control part of a printed circuit board specifies the touched position, and performs a predetermined | prescribed process using this obtained information (for example, refer patent document 1).

  Further, although not disclosed in the document 1, a technique for illuminating the film substrate from the back surface is also known (see, for example, Patent Document 2). Therefore, if these techniques of References 1 and 2 are combined, the touch surface can be illuminated with a light emitter from the back side, and characters and the like engraved on the touch surface can be highlighted.

JP 2007-157107 A JP 2009-135059 A

  By the way, in order to efficiently guide the light from the light emitter to the film substrate, it is desirable to form a cutout hole in the film substrate and to lay the drive electrode and the detection electrode so as to avoid the cutout hole.

  However, since there is no drive electrode or detection electrode at the location corresponding to the cutout hole, the electrode density is reduced and the object detection sensitivity is lowered. On the other hand, the electrode density is high at a portion not corresponding to the surrounding cutout hole, and the object detection sensitivity is high, and this causes a variation in the detection sensitivity of the object in the detection region between a high portion and a low portion. There was a problem.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a capacitive touch pad input device that can solve the above-described problems and can achieve the average detection sensitivity of an object in a detection region, and a device equipped with the same.

  According to a first aspect of the present invention for achieving the above object, there is provided a detection substrate including a detection substrate in which a drive electrode and a detection electrode are laid side by side and having one side as a detection region, and a light emitter that emits light toward the detection substrate. And a control means for detecting the approach of an object to the detection board based on a change in capacitance between the drive electrode and the detection electrode. The capacitive touch pad input device has a cutout hole at a position corresponding to the optical path of light emitted from the light emitter, and the drive electrode and the detection electrode are laid so as to avoid the cutout hole.

And the metal plate which has a through-hole in the position corresponding to the optical path which is installed between a detection board | substrate and a wiring board and goes to a cutout hole from a light-emitting body is provided.
According to the first invention, the drive electrode and the detection electrode are laid side by side on the detection substrate, and the control means detects an object approaching the detection area between the drive electrode and the detection electrode. Detection is possible based on the change in capacitance.

Further, a light emitter is mounted on the wiring board, and the detection board has a cutout hole at a corresponding position in the optical path, and further has a drive electrode and a detection electrode so as to avoid the cutout hole.
As a result, the light of the illuminant can be efficiently guided toward the detection substrate. However, in the portion corresponding to the cutout hole, the electrode density is reduced and the detection sensitivity of the object is lowered, whereas the electrode around it is the electrode. The density is high and the object detection sensitivity is high.

  However, in the present invention, a metal plate is disposed between the detection substrate and the wiring substrate, and this metal plate has a through hole at a position corresponding to the optical path from the light emitter to the cutout hole. Therefore, since it is covered with a metal plate at a place other than the part corresponding to the cutout hole, the detection sensitivity of the object can be lowered even if the electrode density is high, while the detection sensitivity is lowered at the part corresponding to the cutout hole due to the through hole. Without maintenance. As a result, averaging of the detection sensitivity of the object in the detection region can be achieved.

Further, a metal plate is installed between the detection board and the wiring board, and can function as an EMI countermeasure for this wiring board.
According to a second invention, in the configuration of the first invention, an electronic component capable of driving the drive electrode is mounted on the wiring board.
According to the second invention, in addition to the action of the first invention, the metal plate disposed between the detection board and the wiring board even if the electronic component capable of driving the drive electrode generates radiation noise. Can block the emission of unnecessary electromagnetic waves.

  According to a third invention, in the configuration of the first or second invention, a panel member having a front side as an operation surface and a detection board disposed on the back side, and having elasticity in a thickness direction, is interposed between the detection board and the metal plate. And an elastic member, and the detection board is brought into close contact with the back surface of the panel member by holding the metal plate and the elastic member in a state of being pressed in a direction toward the panel member.

According to the third invention, in addition to the effects of the first and second inventions, the panel member, the detection substrate, the elastic member, and the metal plate are arranged in this order, and the elastic member includes the panel member and the detection substrate. And the distance between the detection substrate and the metal plate are adjusted.
Specifically, the distance between the panel member and the detection substrate is short and constant, and an air layer is not formed between the panel member and the detection substrate. Therefore, it is possible to prevent variation in sensitivity due to partial floating of the detection substrate with respect to the panel member.

In addition, since the detection substrate and the metal plate are spaced apart by using the thickness of the elastic member, it is possible to prevent the object detection sensitivity from being rapidly lowered by the metal plate.
According to a fourth aspect of the present invention, in the configuration of the first to third aspects of the present invention, a holding member for holding the metal plate and the wiring board is provided between the metal plate and the wiring board, and the metal plate is bent inward from the edge part The overhanging portion is formed, and with the overhanging portion sandwiched between the wiring board and the holding member, the wiring substrate is screwed and fixed to the holding member to contact the overhanging portion with the ground pattern provided on the wiring substrate. It was made to be characterized.

  According to the fourth invention, in addition to the effects of the first to third inventions, various noises can be canceled by connecting the metal plate to the ground pattern of the wiring board, and the metal plate is sufficient as an EMI countermeasure. The effect can be demonstrated. Further, if the wiring board is screwed and fixed to the holding member with the protruding portion of the metal plate being sandwiched, the metal plate and the ground pattern can be easily connected, and the posture of the metal plate and the detection substrate is stabilized.

According to a fifth aspect of the invention, there is provided a device equipped with the first to fourth capacitive touch pad input devices.
According to the fifth aspect of the invention, in addition to the effects of the first to fourth aspects of the invention, the object detection sensitivity in the detection region can be averaged, and the apparatus operator is not uncomfortable. Contributes to the improvement of reliability.

  According to the present invention, the capacitance type touch pad in which the metal plate having the through hole at the corresponding position in the optical path is installed between the detection substrate and the wiring substrate, and the detection sensitivity of the object in the detection region does not vary. An input device and a device on which the input device is mounted can be provided.

It is the figure which equipped the touchpad input device of 1st Example in the vehicle interior. FIG. 2 is an exploded perspective view of the touch pad input device of FIG. 1. FIG. 3 is a cross-sectional view of the touch pad input device of FIG. 1 as viewed from line III-III in FIG. 2. It is a top view of the film substrate of FIG. It is a block diagram of the touchpad input device containing IC of FIG. It is a disassembled perspective view of the touchpad input device of 2nd Example. It is sectional drawing of the touchpad input device seen from the VII-VII line of FIG.

Preferred embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a passenger compartment of a vehicle 1, in which a seat 4, specifically, a driver's seat and a passenger seat are arranged side by side along the vehicle width direction. The instrument panel 2 is disposed in front of each seat when viewed from the seat 4, and the windshield 6 is also provided in front of the panel 2 when viewed from the seat 4, so that each seat overlooks the traveling direction of the vehicle 1. Can do.

  In this driver's seat, the instruments 8 are arranged in front of the panel 2 and can display the speed, travel distance, shift position, etc. of the vehicle 1. The handle 10 is rotatably attached to the tip of a shaft 12 extending from the lower side of the panel 2 toward the seat 4. The shift lever 14 extends from the peripheral wall of the shaft 12 toward the passenger seat and is movable in the vertical direction.

The air outlet 16 of the air conditioning device is disposed in front of the panel 2 from the driver's seat to the passenger seat, and sends air toward the passenger compartment as the device is activated.
The monitor 18 is installed in front of the panel 2 between the driver seat and the passenger seat. The monitor 18 can display a map, an operation menu, and the like as the navigation device (device) 200 is activated.

The center console 20 protrudes from the lower side of the monitor 18 toward the seat 4, and the slot 22 of the audio device is disposed in the vicinity of the monitor 18, and a CD, MD, or the like can be inserted therein.
In this embodiment, a touch pad unit (capacitive touch pad input device) 24 is provided in an appropriate position on the seat 4 side of the console 20 in the console 20.

  The unit 24 can detect the position on the touch surface 32 of an object (dielectric material such as a finger) touching the touch surface (operation surface) 32. And if the information obtained by this detection is used, the navigation apparatus 200 can be operated. In this embodiment, the touch pad unit 24 for operating the navigation device 200 will be described, but it is naturally possible to operate on-vehicle devices such as the air conditioning device and the audio device described above.

  As shown in FIG. 2, the touch pad unit 24 includes a panel member 30 made of resin. The panel member 30 of a present Example has the touch surface 32 in which the numbers 1-4 were carved on the front side. Further, the panel member 30 has a bowl shape opened downward, and a total of four side surfaces 34 and 36 respectively extend downward from the peripheral edge of the substantially rectangular touch surface 32 to form an open end 38.

  As shown in FIG. 3, a film substrate (detection substrate) 40, a shield plate (metal plate) 60, a holder (holding member) 70, and a printed circuit board (wiring substrate) 80 are arranged inside the panel member 30. Arranged. In FIG. 3, the thicknesses of the film substrate 40 and the shield plate 60 are greatly emphasized to help understand the structure.

The film substrate 40 is cut out from an insulating resin sheet. The film substrate 40 includes the wiring pattern shown in FIG. 4 and detects a position where the touch surface 32 is touched using a change in capacitance.
Specifically, the film substrate 40 of the present embodiment has a substantially rectangular detection region 42, and a cutout hole 48 is drilled through the substrate 40 inside thereof. These cutout holes 48 respectively correspond to the positions of numerals 1 to 4 carved on the touch surface 32.

For example, four drive electrodes 46 and, for example, one detection electrode 44 are laid side by side in the detection area 42, and the detection area 42 is disposed on the back side of the touch surface 32. These electrodes 44 and 46 are made of copper foil.
First, the drive electrode 46 is pulled out from the left end to the right end of the detection region 42 as seen in FIG. 4, and is branched in the vertical direction at an appropriate position in the middle of the detection region 42, and is laid while avoiding the cutout hole 48. . As shown in this figure, the four drive electrodes 46 extend clockwise, and then reach the belt-like wiring portion 47 at the lower end of the detection region 42.

The wiring portion 47 has a length that can be connected to the printed circuit board 80 (FIG. 3), and the drive electrodes 46 are electrically connected to the printed circuit board 80 through the wiring portion 47.
Next, the detection electrode 44 is disposed between the adjacent drive electrodes 46. More specifically, the detection electrode 44 is drawn from the right end to the left end of the detection region 42 as viewed in FIG. 4, and is laid so as not to close the periphery of the cutout hole 48 while avoiding the cutout hole 48.

Further, the detection electrode 44 branches in the vertical direction in the middle like the drive electrode 46, but is disposed between the adjacent drive electrodes 46.
As shown in FIG. 4, after the detection electrodes 44 are gathered together at the left end of the detection region 42, the detection electrodes 44 are drawn toward the lower end of the detection region 42 to reach the wiring portion 47, and are electrically connected to the printed circuit board 80. Connected.

For example, on the opposite side of the detection region 42 having the electrodes 44 and 46, there are vertical drive electrodes (not shown) extending in the vertical direction of the detection region 42 as shown in FIG. The drive electrodes in the vertical direction are also electrically connected to the printed circuit board 80 via the wiring portion 47.
2 and 3 again, the shield plate 60 is formed of a thin plate made of stainless steel, and has a substantially rectangular upper surface 62 that contacts the film substrate 40, specifically, the back surface of the detection region 42.

The shield plate 60 has a lower surface 64 facing the holder 70 on the opposite side of the upper surface 62 (FIG. 3), and has a through-hole 68 formed through the upper surface 62 and the lower surface 64.
These through holes 68 are concentric with the respective cutout holes 48 and correspond to numerical positions on the touch surface 32, but the opening area of the through holes 68 is formed to be slightly larger than the cutout holes 48.

  Subsequently, the holder 70 is made of resin and holds the distance between the shield plate 60 and the printed board 80. The holder 70 has a substantially rectangular upper surface 72 and a lower surface 74 facing the printed circuit board 80 on the opposite side of the upper surface 72 (FIG. 2). Further, the communication hole 78 penetrates the upper surface 72 and the lower surface 74. It has been drilled. These communication holes 78 are concentric with the cutout hole 48, respectively, and the opening area thereof is formed to be substantially equal to and larger than the cutout hole 48.

Next, the printed circuit board 80 includes an upper surface 82 that contacts the holder 70 and a lower surface 84 having the connector 88 of FIG. 3 (FIG. 2), and the wiring portion 47 is received near the connector 88. A possible recess 86 is formed by punching the upper surface 82 and the lower surface 84.
On the upper surface 82, LEDs (light emitting bodies) 90 for illuminating the numbers 1 to 4 are mounted.

Specifically, the center of each LED 90 is arranged concentrically with the cutout hole 48, and the cutout hole 48, the through hole 68, and the communication hole 78 described above function as an optical path of the LED 90.
Thereby, each LED90 can illuminate the touch surface 32 from the back side, and the numbers 1-4 are highlighted.

On the other hand, the wiring portion 47 extending from the detection region 42 straddles the side surfaces of the shield plate 60, the holder 70, and the printed circuit board 80, reaches the lower surface 84 of the printed circuit board 80 via the recess 86, and is connected to the connector 88. doing.
Further, an IC (electronic component) 94 is mounted on the lower surface 84 (FIG. 3), and based on changes in capacitance between the drive electrode 46 and the detection electrode 44 in addition to driving the LED 90 and the drive electrode 46. The approach of the object can be detected.

  More specifically, the IC 94 of this embodiment includes the amplification unit 96, the A / D conversion unit 97, and the control unit (control means) 98 shown in FIG. The drive electrode 46 of the unit 24 described above is connected to the control unit 98 via the connector 88. The detection electrode 44 is connected to the amplification unit 96 via the connector 88 and further connected to the A / D conversion unit 97.

  When a voltage is applied to the drive electrode 46, an electric field having a predetermined potential is generated. When the object touches the touch surface 32 in this state, the capacitance between the drive electrode 46 and the detection electrode 44 changes. Coordinate data can be obtained.

In this state, when an object approaches the drive electrode 46, capacitance is also formed between the object and the drive electrode 46 or between the object and the detection electrode 44. The capacitance between the drive electrode 46 and the detection electrode 44 changes.
Subsequently, the change in potential of the detection electrode 44 is amplified by the amplification unit 96, converted into a digital signal by the A / D conversion unit 97, and then input to the control unit 98.

The control unit 98 obtains coordinate data based on information obtained from the detection electrode 44 and information on the selected drive electrode 46. As a result, the control unit 98 specifies the position touched by the object, and outputs an operation signal to the navigation device 200 described above.
By the way, although the film substrate 40 of the said Example is contacting the shield board 60, you may interpose an elastic member between the film board 40 and the shield board 60. FIG.

Specifically, in the touch pad unit 24A shown in FIGS. 6 and 7, the structure having the same function as in the above embodiment is denoted by the same reference numeral, and detailed description thereof is omitted. The substrate 40 is in close contact with the back surface of the touch surface 32.
More specifically, the touch surface 32 of this embodiment has letters A to F engraved on the front side thereof (FIG. 6), and the object can touch each character as in the above embodiment. .

Inside the panel member 30 of this embodiment, a film substrate 40, a sponge plate (elastic member) 50, a shield plate 60, a holder 70, and a printed circuit board 80 are arranged in this order.
The film substrate 40 has cutout holes 48 corresponding to the positions of alphabet letters A to F, and the detection region 42 is provided with a wiring pattern substantially similar to the wiring pattern described in FIG. It is electrically connected to the printed circuit board 80 via 47.

Here, the sponge plate 50 described above has elasticity in the thickness direction, and has a substantially rectangular upper surface 52 that contacts the back surface of the detection region 42, and a lower surface that faces the shield plate 60 on the opposite side of the upper surface 52. 54 (FIG. 7). The sponge plate 50 has a communication hole 58 that penetrates the upper surface 52 and the lower surface 54.
These communication holes 58 are concentric with the cutout holes 48, respectively, and the opening areas thereof are formed to be approximately equal to the cutout holes 48 and function as an optical path of the LED 90.

  Then, after the shield plate 60, the sponge plate 50, and the film substrate 40 are stacked on the upper surface 72 of the holder 70 in this order from the bottom, when placed inside the panel member 30, the holder 70 places the sponge plate 50 and the shield plate 60 on the panel. It can hold | maintain in the state pressed in the direction which goes to the member 30. FIG. Accordingly, the upper surface 52 of the sponge plate 50 pushes the back surface of the detection region 42 toward the panel member 30, so that the detection region 42 is brought into close contact with the back surface of the panel member 30.

Further, the shield plate 60 of this embodiment is firmly fixed to the holder 70 and the printed circuit board 80.
Specifically, the shield plate 60 includes an L-shaped protruding portion 67. As shown in FIG. 6, the overhanging portion 67 is formed at a position of the peripheral edge (edge portion) 65 facing the wiring portion 47 of the film substrate 40, and extends inward after extending downward. It is formed by bending.

  In the L-shaped projecting portion 67, the vertical surface is formed with a length straddling the side surface of the holder 70, while the horizontal surface is formed to be receivable in the recess 76 formed in the lower surface 74 ( 6), and is sandwiched between the lower surface 74 of the holder 70 and the upper surface 82 of the printed circuit board 80. An introduction hole 69 of a screw 100 described later is provided at an appropriate position on the horizontal plane.

  The printed circuit board 80 is mounted with the LED 90 as in the above embodiment, and the letters A to F are highlighted by illuminating the touch surface 32 from the back side. A ground pattern 92 of the printed circuit board 80 is drawn out at a portion opposite to (FIG. 6). The pattern 92 is formed with a size substantially equal to the horizontal plane of the overhanging portion 67.

The printed board 80 has an introduction hole 89 that penetrates the upper surface 82 and the lower surface 84 at a position corresponding to the introduction hole 69 described above.
Then, with the horizontal surface of the overhanging portion 67 in contact with the holder 70 and the ground pattern 92, the screw 100 is inserted from the lower surface 84 in the order of the introduction holes 89 and 69, Is fixed, the position of the shield plate 60 is firmly fixed.

As described above, according to the touch pad unit 24 (24A) of each embodiment, the drive electrode 46 and the detection electrode 44 are laid side by side on the film substrate 40. In the control unit 98, the detection region 42 is provided. It is possible to detect an object approaching the position based on a change in capacitance between the drive electrode 46 and the detection electrode 44.
Further, the LED 90 is mounted on the printed board 80, and the film board 40 has a cutout hole 48 at a corresponding position in the optical path, and further has a drive electrode 46 and a detection electrode 44 so as to avoid the cutout hole 48. ing.

  Thereby, the light of the LED 90 can be efficiently guided toward the film substrate 40, and even if the installation location of the unit 24 (24A) is in a dark state, it can be easily identified, but it corresponds to the cutout hole 48. In such a place, the electrode density is reduced and the object detection sensitivity is lowered. On the other hand, the electrode density is high around the area, and the object detection sensitivity is high.

  However, in this embodiment, the shield plate 60 is installed between the film substrate 40 and the printed circuit board 80, and this shield plate 60 has the same number of through holes 68 at the corresponding position of the optical path from the LED 90 to the cutout hole 48. doing. Therefore, since it is covered with the shield plate 60 at a place other than the part corresponding to the cutout hole 48, even if the electrode density is high, the object detection sensitivity can be reduced and offset, while the part corresponding to the cutout hole 48 is formed through the through hole. 68 can maintain the detection sensitivity without deteriorating. As a result, the average detection sensitivity of the object in the detection region 42 can be achieved.

Further, the shield plate 60 is installed between the film substrate 40 and the printed circuit board 80, and can function as an EMI countermeasure for the printed circuit board 80.
Specifically, even if the IC 94 or the like that can drive the drive electrode 46 generates radiation noise, the shield plate 60 installed between the film substrate 40 and the printed circuit board 80 reliably blocks emission of unnecessary electromagnetic waves. it can.

  Furthermore, in the touch pad unit 24A, the panel member 30, the film substrate 40, the sponge plate 50, the shield plate 60, the holder 70, and the printed circuit board 80 are arranged in this order. The distance between the film substrate 40 and the distance between the film substrate 40 and the shield plate 60 are adjusted.

Specifically, the distance between the touch surface 32 of the panel member 30 and the detection area 42 of the film substrate 40 is short and constant, and no air layer is formed between the touch surface 32 and the detection area 42. Therefore, it is possible to prevent variation in sensitivity due to partial floating of the detection substrate with respect to the panel member.
In addition, since the distance between the film substrate 40 and the shield plate 60 is spaced apart by using the thickness of the sponge plate 50, the shield plate 60 can prevent the object detection sensitivity from rapidly decreasing.

  Further, if the shield plate 60 is connected to the ground pattern 92 of the printed circuit board 80 as in the touch pad unit 24A, various noises can be canceled, and the shield plate 60 can exhibit a sufficient effect as an EMI countermeasure. Further, if the printed circuit board 80 is screwed and fixed to the holder 70 with the projecting portion 67 of the shield plate 60 being sandwiched, the shield plate 60 and the ground pattern 92 can be easily connected, and the shield plate 60 and the film substrate can be connected. The 40 posture is also stable.

  Further, in the touch pad unit 24 (24A) described above, the detection sensitivity of the object in the detection region 42 can be averaged, and the operator of the unit 24 (24A) is firmly touching the touch surface 32. Therefore, it does not give an unpleasant feeling that it does not react, which contributes to improving the reliability of the navigation device 200.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the claims. For example, the configuration of each of the above embodiments may be omitted in part or may be arbitrarily combined so as to be different from the above.
In each of the above-described embodiments, an example embodied in an operation of a navigation device or the like is shown. However, the capacitive touch pad input device of the present invention is not necessarily limited to an in-vehicle device, and is a personal computer. , Vending machines, automatic teller machines (ATMs), portable devices, television receivers may be mounted on devices such as remote controllers that can be remotely operated, and in this case as well, the detection area Averaging of object detection sensitivity at can be achieved.

24,24A Touchpad unit (Capacitive touchpad input device)
30 Panel member 32 Touch surface (operation surface)
40 Film substrate (detection substrate)
44 Detection electrode 46 Drive electrode 48 Cutout hole 50 Sponge plate (elastic member)
60 Shield plate (metal plate)
65 Perimeter (edge)
67 Overhang portion 68 Through hole 70 Holder (holding member)
80 Printed circuit board (wiring board)
90 LED (light emitter)
92 Ground pattern 94 IC (electronic parts)
98 Control unit (control means)
100 Screw 200 Navigation device (equipment)

Claims (5)

A detection substrate in which a drive electrode and a detection electrode are laid side by side, and one side is a detection region;
A wiring board mounted with a light emitter that emits light toward the detection board and disposed on the opposite side of the detection area of the detection electrode;
Control means for detecting the approach of an object to the detection substrate based on a change in capacitance between the drive electrode and the detection electrode;
The detection substrate has a cutout hole at a position corresponding to an optical path of light emitted from the light emitter, and the capacitive touch pad input device in which the drive electrode and the detection electrode are laid so as to avoid the cutout hole Because
A capacitive touch pad input device comprising a metal plate provided between the detection substrate and the wiring substrate and having a through hole at a position corresponding to an optical path from the light emitter toward the cutout hole. The capacitive touch pad input device according to claim 1,
The capacitive touch pad input device, wherein an electronic component capable of driving the driving electrode is mounted on the wiring board. The capacitive touch pad input device according to claim 1 or 2,
A panel member in which the front side is the operation surface and the detection board is arranged on the back side;
An elastic member having elasticity in the thickness direction and interposed between the detection substrate and the metal plate;
A capacitive touch pad input device, wherein the detection board is brought into close contact with the back surface of the panel member by holding the metal plate and the elastic member in a state of being pressed in a direction toward the panel member. . The capacitive touch pad input device according to any one of claims 1 to 3,
A holding member for holding the metal plate and the wiring board between the metal plate and the wiring board;
The metal plate includes an overhang part that is bent inward from the edge part,
The wiring board is screwed and fixed to the holding member with the overhanging portion sandwiched between the wiring board and the holding member, and the ground pattern provided on the wiring board is brought into contact with the overhanging portion. A capacitive touch pad input device characterized by the above.   An apparatus comprising the capacitive touch pad input device according to any one of claims 1 to 4.

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