JP2004247172A - Measurement device and measuring method of phosphor forming position of cathode-ray tube panel, and manufacturing method of cathode-ray tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure a phosphor forming position on the inside face of a CRT panel in three dimensions. <P>SOLUTION: Slit light is projected from floodlights 2a, 2b toward the inside face of the CRT panel 8 with blackstripes formed. Its reflective light is imaged by a CCD camera 3. Since a measurement head 1 holds the floodlights 2a, 2b and the CCD camera 3 so as to have their light axes in a given angle, the phosphor forming position can be measured in three dimensions by imaged pictures of the CCD camera. By moving the measurement head 1 with a movement mechanism 5, a three-dimensional coordinate value of the phosphor forming position on the inside face of the CRT panel 8 can be measured. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a measuring apparatus and a measuring method for acquiring position information for applying a phosphor on a CRT panel on which a black stripe has been formed, using a dispenser. The present invention also relates to a method for manufacturing a cathode ray tube.
[0002]
[Prior art]
As a method of forming a fluorescent screen of a CRT panel, a number of black stripes are formed on the inner surface of the CRT panel, and then R (red), G (green), and B (blue) phosphors are dispensed between the black stripes. There is known a method of applying by using the method. In this method, it is necessary to know in advance the position where the phosphor is to be formed. Conventionally, the measurement of the phosphor formation position has been performed by image processing using a CCD camera (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-7-21913 (paragraph [0033], FIG. 2)
[0004]
[Problems to be solved by the invention]
However, according to the above-described measurement method, since the CCD camera captures an image of the inner surface of the CRT panel from above, the position information of the phosphor formation position includes a surface substantially parallel to the surface on which the phosphor is formed. Only the position information within the area can be obtained, and the position information in the direction (height direction) orthogonal to the surface cannot be obtained. Therefore, when the inner surface of the CRT panel is a curved surface or the like, the distance between the nozzle position of the dispenser and the inner surface of the CRT panel cannot be set appropriately, and the width of the applied phosphor fluctuates, and the required phosphor width cannot be obtained. However, there is a problem in that an unformed portion is formed, or the width of the phosphor becomes too large to protrude to an adjacent stripe portion, thereby causing color mixing.
[0005]
SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problem when a phosphor is applied and formed on the inner surface of a CRT panel using a dispenser, and simultaneously measures the phosphor formation position in an in-plane direction and also in a height direction. As a result, an object of the present invention is to provide a measuring device and a measuring method of a phosphor forming position, which can control a distance between a nozzle of a dispenser and a panel surface to a predetermined size. Another object of the present invention is to provide a cathode ray tube in which a high-quality phosphor is formed between black stripes.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a phosphor forming position measuring apparatus according to the present invention includes a floodlight that irradiates a slit light on an inner surface of a CRT panel on which a black stripe is formed, and a slit light that irradiates the CRT panel. A camera that captures an image, a measurement head that holds the projector and the camera such that the optical axis of the projector and the optical axis of the camera form a predetermined angle, and moves the measurement head relative to the CRT panel. A moving mechanism for moving, a position detecting means for detecting a relative position of the measuring head with respect to the CRT panel, and an arithmetic unit for arithmetically processing an image taken by the camera and a position signal of the measuring head by the position detecting means. And the arithmetic unit includes three-dimensional coordinates of a position where a phosphor on the inner surface of the CRT panel is to be formed from the captured image and the position signal. Characterized by calculating a.
[0007]
Also, the method for measuring the phosphor formation position of the present invention is characterized in that the projector that irradiates slit light on the inner surface of the CRT panel on which the black stripe is formed, and a camera that is directed to the inner surface of the CRT panel, comprises the projector and the projector. An imaging step of irradiating the slit light on the inner surface of the CRT panel with a measuring head held so that each optical axis of the camera forms a predetermined angle with each other, and imaging the reflected light with the camera; A repetition step of moving the head relative to the CRT panel and repeating the imaging step; and performing arithmetic processing on an image captured by the camera and relative position information of the measurement head with respect to the CRT panel, Calculating a three-dimensional coordinate value of a position on the inner surface of the panel where the phosphor is to be formed.
[0008]
Further, in the method of manufacturing a cathode ray tube according to the present invention, a step of forming a black stripe on an inner surface of a CRT panel, a step of measuring a position between the black stripes, and a step of measuring the position between the black stripes using the measured position information Applying a phosphor to the cathode ray tube, wherein the step of measuring the position between the black stripes comprises: a projector for irradiating slit light to an inner surface of the CRT panel on which the black stripes are formed. A camera directed to the inner surface of the CRT panel, and a measuring head in which the optical axes of the projector and the camera are held at a predetermined angle to each other, and the slit light is transmitted to the inner surface of the CRT panel. Irradiating and imaging the reflected light with the camera, and moving the measuring head relative to the CRT panel And a repetition step of repeating the imaging step, and arithmetically processing an image captured by the camera and relative position information of the measurement head with respect to the CRT panel to calculate three-dimensional coordinate values of positions between the black stripes. And an operation step.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
In the present invention, slit light is applied to the inner surface of a CRT panel on which a black stripe is formed, and reflected light from the CRT panel is imaged by a camera. Since the diffuse reflectance of light is large in the portion where the black stripe is formed and small in the glass portion where the black stripe is not formed, only the slit light diffusely reflected by the black stripe is imaged by the camera. Therefore, by measuring the position of the slit light reflected from the captured image, the position of the position of the black stripe and the position where the phosphor should be formed in a plane substantially parallel to the inner surface of the CRT panel can be measured.
[0010]
Further, since the optical axis of the projector and the optical axis of the camera have a predetermined angle, when the position of the inner surface of the CRT panel relative to the camera in the height direction changes, the position of the slit light to be imaged changes. Therefore, by measuring the amount of change in the position of the slit light, the amount of change in the height direction of the inner surface of the CRT panel can be known. As a result, the position in the height direction of the position where the phosphor should be formed is measured. it can.
[0011]
By repeating this operation while changing the imaging range of the camera by the moving mechanism, it is possible to measure the three-dimensional coordinate value of the phosphor formation position over the entire phosphor formation area on the inner surface of the CRT panel.
[0012]
As described above, according to the measuring device and the measuring method of the present invention, the phosphor formation position can be measured not only in the in-plane direction substantially parallel to the phosphor formation surface of the CRT panel but also in the direction perpendicular thereto. it can. Therefore, by using the obtained three-dimensional coordinate data of the phosphor forming position, it is possible to optimally control the nozzle position of the dispenser in the three-dimensional space in the process of forming the fluorescent screen of the CRT panel using the dispenser. And a high-quality phosphor screen can be formed.
[0013]
Further, according to the method for manufacturing a cathode ray tube of the present invention, a cathode ray tube having a high-quality phosphor screen can be provided.
[0014]
In the above-described measuring device of the present invention, it is preferable that one of the projector and the camera is arranged in a pair with the other being interposed therebetween. According to this preferred configuration, the phosphor forming position can be measured even in the vicinity of the side wall of the CRT panel without being blocked by the side wall.
[0015]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0016]
(Embodiment 1)
FIG. 1 is a side view showing a schematic configuration of an apparatus for measuring a phosphor forming position of a CRT panel according to Embodiment 1 of the present invention. As shown in FIG. 1, an XYZ orthogonal coordinate system is set in which the XY plane is in the horizontal plane and the Z direction is in the height direction. In FIG. 1, reference numeral 1 denotes a measuring head, which includes a CCD camera 3 and laser slit light projectors 2a and 2b arranged on both sides thereof. The relative positions of the CCD camera 3 and the laser slit light projectors 2a, 2b are maintained such that the respective optical axes of the slit light projected from the light projectors 2a, 2b and the optical axis of the CCD camera 3 form an angle θ. Is fixed. Reference numeral 4 denotes a power supply unit for driving the laser slit light projector 2 and the CCD camera 3. Reference numerals 5x, 5y, and 5z denote moving mechanisms for moving the measuring head 1 to arbitrary positions in the X, Y, and Z directions, respectively. The three-axis orthogonal robot 5 is configured by these moving mechanisms 5x, 5y, and 5z. . A robot controller 6 controls the three-axis orthogonal robot 5. Reference numeral 7 denotes a panel stage for fixing a CRT panel 8 on which black stripes have been formed, and reference numeral 9 denotes an arithmetic processing unit which inputs and processes the position coordinates of the three-axis orthogonal robot 5 and the image signal captured by the CCD camera 3.
[0017]
FIG. 2 is a perspective view showing the positional relationship between the laser slit light projectors 2 a and 2 b of the measuring head 1, the CCD camera 3, the black stripe 10 formed on the CRT panel 8, and the coordinate axes of the three-axis orthogonal robot 5. The optical axis of the CCD camera 3 is parallel to the Z axis, and each optical axis of the laser slit light projectors 2a and 2b is parallel to the YZ plane. The slit light projected from the laser slit light projectors 2a and 2b is diffused light in a plane orthogonal to the YZ plane. The CRT panel 8 is arranged such that the black stripe 10 formed on the inner surface thereof is parallel to the Y axis. Accordingly, the illumination stripe formed on the inner surface of the CRT panel 8 by the slit light emitted from the laser slit light projectors 2a and 2b is substantially orthogonal to the black stripe 10 (strictly speaking, when the inner surface of the CRT panel 8 is a curved surface). Is not orthogonal to the illumination stripe and the black stripe 10). The CCD camera 3 captures the reflected light of the slit light from the black stripe 10 formed on the inner surface of the CRT panel 8.
[0018]
The measurement is performed by moving the measuring head 1 by, for example, a three-axis orthogonal robot 5 in a direction indicated by an arrow in FIG. That is, the measuring head 1 is arranged near the end on the E side of the CRT panel 8, and is moved from one (N side) end to the other (S side) end of the CRT panel 8 along the Y axis. Next, the measurement head 1 is slightly moved to the W side along the X axis, and the measurement head 1 is moved from the other (S side) end of the CRT panel 8 to one (N side) end along the Y axis. Thus, the entire surface of the phosphor forming surface of the CRT panel 8 is scanned. At this time, the measuring head 1 is so arranged that at least one of the slit lights from the laser slit light projectors 2a and 2b and the reflected light from the phosphor forming surface of the CRT panel 8 always enters the field of view of the CCD camera 3. Is also moved in the Z-axis direction with respect to the phosphor forming surface of the CRT panel 8.
[0019]
As shown in FIG. 4, when the position of the measuring head 1 is near the N side of the CRT panel 8, the projection of the laser slit light projector 2b is stopped, and the slit light projected from the laser slit light projector 2a causes the CRT panel to emit light. 8 is formed.
[0020]
The diffuse reflectance of the black stripe portion is large, and the diffuse reflectance of the glass portion where no black stripe is formed is small. Therefore, as shown in FIG. 5, the CCD camera 3 captures the reflected light of the slit light extending in a broken line shape. This captured image is input to the arithmetic processing unit 9. The arithmetic processing unit 9 calculates the coordinates of both end positions of each line constituting the broken line as the black stripe position. Next, the coordinates (x, y) of the intermediate position between the ends (eg, (XNP, YNP) and (XNN, YNN)) of adjacent lines constituting the broken line (for example, the coordinates of the intermediate position PN ( (XNP + XNN) / 2, (YNP + YNN) / 2)) is calculated as the coordinate value of the phosphor forming position in the captured image. In this way, the coordinate values (x, y) in the captured image of the phosphor forming positions..., PN-1, PN, PN + 1,.
[0021]
, PN-1, PN, PN + 1,... In the captured image of the CCD camera 3 thus obtained are input from the robot controller 6 to the coordinate values (x, y). , The position coordinates (X, Y) of the measuring head 1 at that time are combined, and the coordinate values (X + x, X) of the phosphor forming positions..., PN-1, PN, PN + 1,. Y + y) is calculated.
[0022]
By repeating these operations while moving the measuring head 1 as shown in FIG. 3, substantially lattice points between the black stripes 10,..., P_Rmn, P_Gmn, P_Bmn,. .. Can be obtained as the phosphor formation position.
[0023]
When the measuring head 1 moves from the N side to the S side and passes through the center of the CRT panel 8 and enters a region near the S side, the laser slit light projector 2a stops emitting light, and instead, the laser slit light projector Slit light is emitted from 2b, and the reflected light of this slit light is imaged by the CCD camera 3, and the same processing as described above is repeated. As described above, when the measuring head 1 is located in the region closer to the N side, the slit light is projected from the projector 2a, and when the measuring head 1 is located in the region closer to the S side, the slit light is projected. By providing the two laser slit light projectors 2a and 2b with the CCD camera 3 interposed therebetween, the projected slit light can be measured over the entire surface of the phosphor forming surface of the CRT panel 8 without being blocked by the side wall of the CRT panel 8. Will be possible.
[0024]
.., P_Rmn, P_Gmn, P_Bmn,..., The Z-axis coordinate values of the respective phosphor forming positions (the substantially grid-like points between the black stripes 10) are determined by the slit light 11 observed by the CCD camera 3. Is calculated by measuring the position in the Y direction. That is, as shown in FIG. 7, since the optical axis of the laser slit light projector 2a (2b) is inclined by the angle θ with respect to the optical axis of the CCD camera 3, the displacement ym of the slit light from the reference position 0 in the Y direction is ym. By measuring −y0, the displacement in the Z-axis direction from the reference position 0 is obtained from zm−z0 = (ym−y0) / tan θ. As in the measurement of the coordinate values in the XY plane, the Z-axis coordinate values of the measuring head 1 at this time are combined to obtain the Z-axis coordinate values of the respective phosphor-forming positions.
[0025]
As described above, according to the measuring apparatus of the present embodiment, substantially lattice point-like points,..., P_Rmn, P_Gmn, and P_Bmn, existing in the stripe-shaped portions where the phosphors are to be formed between the black stripes 10. ,... Can be obtained. Therefore, by moving the nozzle position of the dispenser while controlling the XYZ three-axis directions in accordance with the obtained XYZ coordinate values of each point, the black stripe 10 is formed with an appropriate width over the entire phosphor forming surface. Since it can be formed between them, a high-quality phosphor surface can be formed.
[0026]
(Embodiment 2)
FIG. 8 is a side view showing a schematic configuration of an apparatus for measuring a phosphor formation position of a CRT panel according to Embodiment 2 of the present invention. In the measuring device of the first embodiment, the measuring head 1 is constituted by two laser slit light projectors 2a and 2b and one CCD camera 3, but in the measuring device of the second embodiment, the measuring head 1 It is composed of one laser slit light projector 2 and two CCD cameras 3a and 3b. In the present embodiment, the CCD cameras 3a and 3b are arranged so as to sandwich the laser slit light projector 2, and each optical axis of the CCD cameras 3a and 3b has an angle θ with respect to the optical axis of the laser slit light projector 2. As shown, the relative positions of the laser slit light projector 2 and the CCD cameras 3a and 3b are held and fixed. The configuration other than the above is the same as that of the first embodiment.
[0027]
FIG. 9 is a perspective view showing the positional relationship between the laser slit light projector 2 and the CCD cameras 3a and 3b of the measuring head 1, the black stripes 10 formed on the CRT panel 8, and the coordinate axes of the three-axis orthogonal robot 5. The optical axis of the laser slit light projector 2 is parallel to the Z axis, and each optical axis of the CCD cameras 3a and 3b is parallel to the YZ plane. The slit light projected from the laser slit light projector 2 is diffused light in a plane orthogonal to the YZ plane. The CRT panel 8 is arranged such that the black stripe 10 formed on the inner surface thereof is parallel to the Y axis. Therefore, the illumination stripe formed on the inner surface of the CRT panel 8 by the slit light emitted from the laser slit light projector 2 is orthogonal to the black stripe 10. The CCD cameras 3a and 3b capture the reflected light of the slit light from the black stripe 10 formed on the inner surface of the CRT panel 8.
[0028]
As in the first embodiment, the measurement is performed while the measuring head 1 is moved by the three-axis orthogonal robot 5 in, for example, the direction shown by the arrow in FIG. At this time, the measuring head 1 is mounted on the CRT panel so that the reflected light of the slit light from the laser slit light projector 2 from the phosphor forming surface of the CRT panel 8 always enters at least one of the visual fields of the CCD cameras 3a and 3b. 8 is also moved in the Z-axis direction with respect to the phosphor forming surface.
[0029]
During the measurement, when the measuring head 1 is located in the region closer to the N side in the Y-axis direction as shown in FIG. 10, the image taken by the CCD camera 3a is taken when the measuring head 1 is located in the region closer to the S side, Each is processed to determine the phosphor formation position. By providing two CCD cameras 3a and 3b with the laser slit light projector 2 interposed therebetween, the reflected light of the slit light from the laser slit light projector 2 on the CRT panel 8 surface is not blocked by the side wall of the CRT panel 8. An image can always be captured by at least one of the two CCD cameras 3a and 3b, and measurement can be performed over the entire surface of the CRT panel 8 on which the phosphor is formed.
[0030]
As shown in FIG. 11, the CCD camera 3a (or 3b) captures reflected light extending in a broken line shape of the slit light irradiated on the black stripe 10. The arithmetic processing unit 9 performs the same arithmetic processing as in the first embodiment based on the captured image to obtain the captured image of the phosphor forming position..., PN-1, PN, PN + 1,. Are calculated in order.
[0031]
, PN-1, PN, PN + 1,... In the captured image of the CCD camera 3a (or 3b) obtained in this way, and x-coordinate values are input from the robot controller 6. , PN-1, PN, PN + 1,..., PN-1, PN, PN + 1,... In the XYZ coordinate system as in the first embodiment. .. Are calculated (X + x, Y).
[0032]
In the present embodiment, since the optical axis of the laser slit light projector 2 is parallel to the Z-axis and the slit light 11 extends in the X-axis direction, the phosphor forming positions..., PN-1, PN, PN + 1. ,... Are all the same as shown in FIG. 11, so that the memory for storing the measured values can be reduced as compared with the first embodiment.
[0033]
The Z-axis coordinate value of each phosphor forming position is calculated by measuring the position of the slit light 11 in the captured image in the y direction observed by the CCD camera 3a (or 3b). That is, as shown in FIG. 12, since the optical axis of the laser slit light projector 2 is inclined by the angle θ with respect to the optical axis of the CCD camera 3a (or 3b), the displacement of the slit light from the reference position 0 in the y direction is made. By measuring ym-y0, the displacement in the Z-axis direction from the reference position 0 can be obtained from zm-z0 = (ym-y0) / sin θ. As in the measurement of the coordinate values in the XY plane, the Z-axis coordinate values of the measuring head 1 at this time are combined to obtain the Z-axis coordinate values of the respective phosphor-forming positions.
[0034]
As described above, according to the measuring apparatus of the present embodiment, each XYZ of the substantially lattice point (phosphor formation position) existing in the stripe portion where the phosphor between black stripes 10 is to be formed is provided. Coordinate values can be obtained. Therefore, by moving the nozzle position of the dispenser while controlling the XYZ three-axis directions in accordance with the obtained XYZ coordinate values of each point, the black stripe 10 is formed with an appropriate width over the entire phosphor forming surface. Since it can be formed between them, a high-quality phosphor surface can be formed.
[0035]
The configuration of the cathode ray tube to which the present invention is applied is not particularly limited, and can be applied to known ones. Further, the method for manufacturing a cathode ray tube according to the present invention is obtained by performing the measurement of the phosphor formation position according to the first or second embodiment and obtaining the above measurement when applying the phosphor between the black stripes. It can be performed using a known process except that three-dimensional data is used.
[0036]
【The invention's effect】
As described above, according to the measuring apparatus and the measuring method of the present invention, the phosphor formation position is measured not only in the in-plane direction substantially parallel to the phosphor formation surface of the CRT panel but also in the direction perpendicular thereto. Can be. Therefore, by using the obtained three-dimensional coordinate data of the phosphor forming position, it is possible to optimally control the nozzle position of the dispenser in the three-dimensional space in the process of forming the fluorescent screen of the CRT panel using the dispenser. And a high-quality phosphor screen can be formed.
[0037]
Further, according to the method for manufacturing a cathode ray tube of the present invention, a cathode ray tube having a high-quality phosphor screen can be provided.
[Brief description of the drawings]
FIG. 1 is a side view showing a schematic configuration of a measuring device of a phosphor forming position of a CRT panel according to a first embodiment of the present invention; FIG. 2 is a perspective view of a measuring device according to a first embodiment of the present invention; FIG. 3 is a perspective view showing an arrangement of a camera and a black stripe in a space. FIG. 3 is a plan view showing an example of a moving direction of a measuring head in the measuring apparatus according to the first embodiment of the present invention. FIG. 5 is a side view for explaining interference between slit light and a panel side wall in the measuring device according to the first embodiment. FIG. 5 shows slit light applied to an inner surface of a CRT panel in the measuring device according to the first embodiment of the present invention. FIG. 6 is a partial enlarged plan view of the measuring device according to the first embodiment of the present invention. FIG. 7 is a diagram showing a measurement position of a phosphor forming position. Position in the height direction of the position FIG. 8 is a side view showing a schematic configuration of an apparatus for measuring a phosphor forming position of a CRT panel according to a second embodiment of the present invention. FIG. 9 is a second embodiment of the present invention. FIG. 10 is a perspective view showing an arrangement of a projector, a CCD camera, and a black stripe in a space in the measuring apparatus of FIG. 10. FIG. 10 illustrates interference between reflected light of slit light and panel side walls in the measuring apparatus of the second embodiment of the present invention. FIG. 11 is a partially enlarged plan view showing slit light applied to the inner surface of a CRT panel in the measuring apparatus according to the second embodiment of the present invention. FIG. 12 is a measurement view according to the second embodiment of the present invention. Diagram showing the principle of measuring the position of the phosphor formation position in the height direction in the apparatus.
DESCRIPTION OF SYMBOLS 1 Measuring head 2, 2a, 2b Laser slit light projector 3, 3a, 3b CCD camera 4 Laser slit light projector and drive power supply of CCD camera 5 3-axis orthogonal robot 6 Robot controller 7 Panel stage 8 CRT panel 9 Arithmetic processing unit 10 Black stripe

Claims (3)

A projector for irradiating the slit light on the inner surface of the CRT panel on which the black stripe is formed;
A camera for imaging the slit light applied to the CRT panel;
A measuring head that holds the projector and the camera such that the optical axis of the projector and the optical axis of the camera form a predetermined angle,
A moving mechanism for moving the measuring head relative to the CRT panel;
Position detecting means for detecting a relative position of the measuring head with respect to the CRT panel;
An arithmetic unit that arithmetically processes a captured image of the camera and a position signal of the measuring head by the position detection unit,
The apparatus for calculating a phosphor-forming position of a CRT panel, wherein the computing device computes three-dimensional coordinate values of a position where a phosphor on the inner surface of the CRT panel is to be formed from the captured image and the position signal. The projector that irradiates the slit light to the inner surface of the CRT panel on which the black stripe is formed, and the camera that is directed to the inner surface of the CRT panel, such that the optical axes of the projector and the camera make a predetermined angle with each other. Using a held measurement head, irradiating the slit light on the inner surface of the CRT panel, and imaging the reflected light with the camera;
A repeating step of moving the measuring head relative to the CRT panel and repeating the imaging step;
Calculating a three-dimensional coordinate value of a position where a phosphor on the inner surface of the CRT panel is to be formed by arithmetically processing an image captured by the camera and relative position information of the measurement head with respect to the CRT panel. A method for measuring the position of a phosphor formed on a CRT panel. Forming a black stripe on the inner surface of the CRT panel;
Measuring the position between the black stripes,
Applying a phosphor between the black stripes using the measured position information, the method for manufacturing a cathode ray tube,
The step of measuring the position between the black stripes,
A projector for irradiating slit light to the inner surface of the CRT panel on which the black stripe is formed, and a camera directed to the inner surface of the CRT panel, such that the optical axes of the projector and the camera make a predetermined angle with each other. An imaging step of irradiating the inner surface of the CRT panel with the slit light using a measurement head held in the camera, and imaging the reflected light with the camera;
A repeating step of moving the measuring head relative to the CRT panel and repeating the imaging step;
A calculating step of calculating a three-dimensional coordinate value of a position between the black stripes by performing arithmetic processing on an image captured by the camera and relative position information of the measuring head with respect to the CRT panel. Pipe manufacturing method.

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