JP7208484B2 - GOLF BALL, GOLF BALL BEHAVIOR MEASURING DEVICE, AND METHOD OF APPLYING DESIGN TO GOLF BALL - Google Patents

Description

The present invention relates to a golf ball, a golf ball behavior measuring device, and a method of applying a design to a golf ball.

Conventionally, in measuring the behavior of a golf ball, a method of calculating parameters indicating various behaviors by performing image processing on a plurality of images taken with the golf ball has been used.
For example, Patent Document 1 below aims to measure the behavior of a moving body (golf ball) without using special equipment, and describes a first image in which the golf ball is placed at a movement start point, The behavior of the golf ball is measured based on the second image, which is the image after the golf ball has been hit and started to move. For example, the direction of movement can be calculated from the direction of displacement from the position of the golf ball in the two images. Also, the direction of the axis of rotation can be calculated from the difference between the positions and orientations of the golf ball patterns in the two images.

JP 2016-86952 A

When measuring the behavior of a golf ball using an image, as in the above-described prior art, a visually recognizable pattern (mark, hereinafter referred to as a "pattern for behavior measurement") is attached to the surface of the golf ball, and the pattern on the image is displayed. The rotation state of the ball is calculated based on the position.
On the other hand, general golf balls are provided with the name of the manufacturer or brand of the golf ball, a logo mark, or a design or character to identify the owner of the golf ball (hereinafter referred to as "design design"). ing.
If a behavior measurement pattern is added to a golf ball already provided with a design pattern, the pattern occupies a larger proportion of the surface of the golf ball, thereby degrading the design of the golf ball. In addition, when extracting the position of the pattern for behavior measurement on the image in the behavior measurement process, the accuracy of extracting the pattern for behavior measurement may decrease due to the influence of the design pattern, and the accuracy of the behavior measurement process may decrease. There is a problem.
In order to deal with such problems, for example, there is a method of using a golf ball to which only the pattern for behavior measurement is attached without the design pattern when measuring behavior. It is not possible to accommodate users who want to use golf balls (general golf balls with design patterns attached).

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a pattern for behavior measurement without degrading the design of a golf ball.

In order to achieve the above object, a golf ball according to the present invention is a golf ball having a first design on its surface, wherein the first design is used for measuring the behavior of the golf ball, and A material that is visible in the same color as the surface under irradiation with visible light and can be distinguished in a different color from the surface under irradiation with invisible light of a predetermined wavelength is arranged on the surface, and the A second pattern is further provided on the surface, and the second pattern is visually recognized in a color different from that of the surface under irradiation with visible light, and is identified as the same color as that of the surface under irradiation with invisible light. It is characterized in that it is formed by placing a material on the surface .
The golf ball according to the present invention is characterized in that the absorbance of the invisible light of the material forming the first pattern is higher than the absorbance of the surface of the invisible light by a predetermined value or more.
Further , the golf ball according to the present invention is characterized by further comprising, on the surface of the first pattern, a colorless and transparent protective layer under irradiation with visible light and under irradiation with invisible light.
A golf ball behavior measuring device according to the present invention is a golf ball behavior measuring device for measuring the behavior of a golf ball according to any one of claims 1 to 3 , wherein the golf ball is positioned in an imaging area. an invisible light irradiation means for irradiating the golf ball with the invisible light; and the camera for photographing an image of the golf ball irradiated with the invisible light by the invisible light irradiation means. and behavior measuring means for calculating, based on the image, at least one of the moving direction, moving speed, rotation axis direction, and spin component of the golf ball immediately after hitting. and
Further, in the golf ball behavior measuring device according to the present invention, the camera is provided with a filter that selectively transmits the invisible light of the wavelength irradiated by the invisible light irradiation means.
A method of applying a design to a golf ball according to the present invention is a method of applying a design to a golf ball, wherein the surface of the golf ball appears to have the same color as the surface under irradiation of visible light, and the light has a predetermined wavelength. A first pattern used for behavior measurement of the golf ball is provided by arranging a material that is visible in a color different from that of the surface under irradiation of invisible light, and the golf ball is provided with the first pattern. A second pattern is formed on the surface of the ball by arranging a material that is visible in a color different from that of the surface under irradiation with visible light and is visible in the same color as the surface under irradiation with invisible light. is given in advance .

According to the present invention, the first pattern used to measure the behavior of the golf ball can be identified only under irradiation of invisible light. The pattern is not visually recognized, which is advantageous for improving the design of the golf ball.
Further, in the case where a golf ball has a second design visible under visible light, applying an arbitrary design as the second design is advantageous in further improving the design of the golf ball. Become. In addition, since the second pattern is identified in the same color as the surface of the golf ball under invisible light, only the first pattern is recognized on the surface of the golf ball. Useful for improving.

1 is an external view of a golf ball 10 according to an embodiment; FIG. 1 is an external view of a golf ball 10 according to an embodiment; FIG. 2 is an explanatory diagram showing the configuration of a behavior measuring device 20; FIG. FIG. 3 is an explanatory view showing a state where the golf ball 10 is placed on the tee 34; 2 is a block diagram showing the configuration of a computer 28; FIG. 2 is a block diagram showing a functional configuration of the behavior measuring device 20; FIG. 4 is a flowchart showing a procedure of processing by the behavior measuring device 20; FIG. 3 is an explanatory diagram schematically showing an example of an image captured by an image capturing unit 206; FIG. 3 is an explanatory diagram schematically showing an example of an image captured by an image capturing unit 206; FIG. 7 is an explanatory diagram showing another configuration example of the behavior measuring device 20;

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a golf ball, a golf ball behavior measuring device, and a method of applying a design to a golf ball according to the present invention will be described below in detail with reference to the accompanying drawings.
1 and 2 are external views of a golf ball 10 according to an embodiment, and FIG. 2 is a view taken along the arrow S in FIG. In each figure, symbol A indicates the appearance under irradiation of visible light, and symbol B indicates the appearance under irradiation of invisible light. In the present embodiment, the color of surface 10A of golf ball 10 (the color visible under irradiation with visible light) is white.

As shown in FIG. 1, a golf ball 10 has a behavior measurement pattern (first pattern) 12 applied to its surface 10A. The behavior measurement pattern 12 is used for behavior measurement processing in a behavior measurement device 20 (see FIG. 3), which will be described later. In the present embodiment, the pattern 12 for behavior measurement has two circular figures 12A and 12B and one X mark 12C arranged at equal distances from each other.
In addition, as shown in FIG. 2, a pattern similar to the behavior measurement pattern 12 (second behavior measurement pattern) is added to the anticentric position of the behavior measurement pattern 12 (first behavior measurement pattern). It is

The pattern 12 for behavior measurement is visible in the same color as the surface 10A of the golf ball 10 under irradiation with visible light, and is identifiable in a color different from that of the surface 10A under irradiation with invisible light of a predetermined wavelength. It is formed by being arranged on.
Here, visible light is light belonging to a wavelength band visible to the human eye among electromagnetic waves (light), and specifically refers to light in a wavelength band from approximately 380 nm to 810 nm. In addition, invisible light is light having a wavelength out of the wavelength band of visible light among electromagnetic waves (light). Specifically, ultraviolet rays are on the shorter wavelength side than the visible light wavelength band, and infrared rays are on the longer wavelength side than the visible light wavelength band.

The behavior measurement pattern 12 is printed on the surface 10A of the golf ball 10 using invisible ink, for example. Invisible ink is formed so that the optical properties for visible light (reflectance, transmittance, absorptance, etc.) and the optical properties for invisible light (infrared or ultraviolet) differ greatly, and under visible light irradiation It is colorless and transparent, that is, it looks the same color as the surroundings (surface 10A of golf ball 10), but it looks different from the surroundings under irradiation of invisible light. In this specification, the term "colorless and transparent" means that the color of the surface 10A of the golf ball 10 is transmitted to such an extent that it is difficult for the user to see the pattern 12 for behavior measurement during normal use of the golf ball 10. point to
Specifically, for example, ink with high visible light and ultraviolet transmittance, low absorbance and low reflectance, and high infrared absorbance (infrared absorbing ink) and ink with high infrared reflectance (infrared reflecting ink) ), ink that produces fluorescence when exposed to ultraviolet light (ultraviolet fluorescent ink), and the like.
Further, for example, an ink (material) that is visible in the same color (white in this embodiment) as the surface 10A of the golf ball 10 under irradiation with visible light and visible in a different color (other than white) from the surrounding area under irradiation with invisible light. A pattern 12 for behavior measurement may be formed.

In this embodiment, the pattern 12 for behavior measurement shall be printed with infrared absorption ink, for example.
By using such an ink (infrared absorption ink), the behavior measurement pattern 12 is visually recognized in the same color as the surface 10A of the golf ball 10 as shown in FIG. 1A under visible light irradiation (in FIG. 1A, The pattern 12 for behavior measurement is illustrated by shading). Further, under irradiation of invisible light (infrared rays), as shown in FIG. 1B, the surface 10A of the golf ball 10 is distinguished by a darker color (shown in black in FIG. 1B).
More specifically, the infrared (invisible light) absorptance of the infrared absorbing ink is significantly higher (at least a predetermined value) than the infrared (invisible light) absorptance of the surface 10A of the golf ball 10 . Therefore, the pattern 12 for behavior measurement is recognized darker than the surface 10A of the golf ball 10 when irradiated with infrared rays. In this case, compared to the case of making the behavior measurement pattern 12 identifiable by reflecting invisible light, for example, as with infrared reflective ink, the contour of the behavior measurement pattern 12 during image processing in the behavior measurement device 20 described later is easy to grasp, and the accuracy of behavior calculation can be improved.

It should be noted that the pattern 12 for behavior measurement is preferably visually recognized as having the same color as the surface 10A of the golf ball 10 under irradiation of visible light, that is, recognized by a person (user) as being substantially colorless and transparent, but under irradiation of invisible light. may not necessarily be visible to humans (users). The pattern 12 for behavior measurement may be identifiable in a color different from that of the surface 10A of the golf ball 10 on an image captured by a camera 22 of the behavior measurement device 20, which will be described later, under illumination of invisible light.

Further, the behavior measurement pattern 12 is not limited to being printed on the surface 10A of the golf ball 10 in advance. It may be attached to the surface 10A of the ball 10. FIG.

Further, as shown in FIG. 2, the golf ball 10 further has a design pattern (second pattern) 14 on its surface 10A. The design pattern 14 is, for example, a manufacturer name or brand name of the golf ball 10, a logo mark, or a pattern for identifying the owner of the golf ball.
In this embodiment, as the design pattern 14, the letters "GOLF", which is the name of the manufacturer of the golf ball 10, are given. In addition, in order to accurately perform measurement by the behavior measuring device 20, which will be described later, alignment marks (▴) for positioning the golf ball 10 at the hitting start position (on the tee) are placed on the left and right sides of the letters "GOLF". are placed.
Also, a design (second design pattern) similar to the design design 14 is provided at the opposite position of the design design 14 (first design design) shown in FIG.

The design pattern 14 is visually recognized in a color different from that of the surface 10A of the golf ball 10 under irradiation with visible light, and is identified as having the same color as the surface 10A under irradiation with invisible light, and is arranged on the surface 10A. It is formed by
The design pattern 14 is printed on the surface 10A of the golf ball 10 using, for example, black ink or color ink that does not contain carbon black. Black ink or color ink that does not contain carbon black is visually recognized as a predetermined color (a color other than black or white), that is, a color different from the surroundings (the white color of the surface 10A of the golf ball 10) under irradiation with visible light, and is invisible light. Under illumination, it is recognized in almost the same color as its surroundings. In other words, as an ink for design pattern printing, the ink has a high absorption rate of visible light (in the case of black), or reflects a specific wavelength of visible light (in the case of color), and has a high transmittance of invisible light. is preferably used.
Specifically, for example, while having a black appearance, such as infrared transmissive dark ink (generally referred to as IR (infrared) ink, IR transmissive ink, etc.) described in International Publication No. 2016/052641, Inks with sufficient infrared transparency can be used.

By using such an ink (IR transmissive ink, etc.), the design pattern 14 is visually recognized in a different color from the surface 10A of the golf ball 10 as shown in FIG. 2A under visible light irradiation (see FIG. 2A shows the design pattern 14 in black). Also, under irradiation of invisible light (infrared rays), as shown in FIG. 2B, the surface 10A of the golf ball 10 is identified by the same color (indicated by dotted lines in FIG. 2B).

It is preferable that the design pattern 14 has a color different from that of the surface 10A of the golf ball 10 under visible light irradiation, that is, the design pattern 14 can be recognized by a human (user). does not necessarily need to be colorless, and the contrast with the surface 10A may be lowered to the extent that the behavior measurement pattern 12 can be easily distinguished from the image captured by the camera 22 of the behavior measurement device 20.

Next, the behavior measuring device 20 that measures the behavior of the golf ball 10 will be described.
In the present embodiment, the behavior measurement device 20 is used to measure the movement direction, movement speed, rotation axis direction, and spin component of the golf ball 10 immediately after hitting.
The configuration of the behavior measurement device 20 and the procedure of behavior measurement processing, etc., which will be described below, are examples, and various conventionally known methods can be adopted as specific methods for measuring the behavior of the golf ball 10 using images. be.

3A and 3B are explanatory diagrams showing the configuration of the behavior measuring device 20. FIG. 3A is a schematic side view, and FIG. 3B is a top view.
FIG. 3A shows a measurer (player) I attempting to hit a golf ball 10 with a golf club 32 . Although the patterns are omitted in FIG. 3, the golf ball 10 is provided with behavior measurement patterns 12 and design patterns 14 as shown in FIGS.
The golf ball 10 is placed on a tee 34 inserted into the ground (horizontal surface) G, and is hit by the golf club 32 in this state to start moving. That is, in the example of FIG. 3A, the position of the golf ball 10 on the tee 34 is the movement start point P0.
Whether the measurement is performed with the golf ball 10 placed on the tee 34 or with the golf ball 10 placed on the ground G, that is, whether the position of the golf ball 10 on the tee 34 is the movement start point. , and whether the position of the golf ball 10 on the ground G is set as the starting point of movement is arbitrarily determined by the person taking the measurement.
Reference character X denotes the target movement direction when the golf ball 10 is hit by the golf club 32 . Hereinafter, the origin of the coordinates of the space in which the behavior measurement device 20 is installed is the movement start point P0, the target movement direction X is the x-axis in the direction parallel to the ground G, the direction opposite to the direction of gravity is the z-axis, the x-axis, and the x-axis. The direction perpendicular to the z-axis is defined as the y-axis. In FIG. 3, for convenience of illustration, each coordinate axis is shown at a position away from the movement start point P0, which is the origin.

As shown in FIG. 4, when the measurer I places the golf ball 10 on the tee 34, the character "GOLF", which is the design pattern 14, is directed upward and in a direction that the user can read. The vertex of the mark (▴) is directed in the target movement direction X. As a result, the pattern 12 for behavior measurement faces the side of the camera 22 positioned in the y-axis direction, and the pattern 12 for behavior measurement can be reliably reflected in the image captured by the camera 22 .
Particularly, in the present embodiment, it is difficult to align the behavior measurement pattern 12 with the camera 22 using the behavior measurement pattern 12 itself because it is difficult to see the behavior measurement pattern 12 under visible light. By providing the design pattern 14 with the alignment mark, the behavior measurement pattern 12 can be reliably reflected in the image captured by the camera 22, and the behavior measurement accuracy can be improved.

The behavior measurement device 20 includes a camera 22 , an infrared lamp 23 (invisible light irradiation means), a microphone 24 , a Doppler sensor 25 and a computer 28 .
The camera 22 is a camera that captures a still image, and is arranged so that an area including the movement start point P0 of the golf ball 10 is taken as an image capturing area. In this embodiment, the camera 22 is fixedly installed in the vicinity of the ground G, and photographs the inside of the photographing area H including the movement start point P0 as shown in FIG. 3B.
Images captured by the camera 22 are output to a computer 28, which will be described later.
Further, the photographing timing of the camera 22 is controlled by the photographing control means 208 of the computer 28, which will be described later.

The infrared lamp 23 is an example of invisible light irradiation means, and emits infrared rays in the present embodiment. The infrared lamp 23 is lit in conjunction with the photographing timing of the camera 22 and irradiates the vicinity of the photographing region H with infrared rays. As a result, the golf ball 10 can be clearly shown in the photographed image. The computer 28 may control the turning on/off of the infrared lamp 23 .
In FIG. 3B, illustration of the infrared lamp 23 is omitted in order to clarify the positional relationship between the camera 22 and a Doppler sensor 25, which will be described later.
In this embodiment, the camera 22 and the infrared lamp 23 are shown separately for convenience of illustration, but the camera 22 and the infrared lamp 23 may be housed in one unit. In this case, for example, the camera 22 and the infrared lamp 23 are housed in the housing (generally rectangular) of the unit, and the lens of the camera 22 and the infrared lamp 23 are mounted on the front side (surface facing the golf ball 10) of the housing. to place

A filter that cuts off light other than infrared rays (wavelength band peaking at the wavelength of light emitted from the infrared lamp 23) may be provided on the surface of the lens (not shown) of the camera 22. FIG. That is, the camera 22 may be provided with a filter that selectively transmits the invisible light of the wavelength irradiated by the invisible light irradiation means (infrared lamp 23).
As a result, the influence of ambient visible light and the like can be eliminated, and the outline of the golf ball 10 and the pattern 12 for behavior measurement under the irradiation of the infrared lamp can be photographed more clearly. Moreover, even when the surface 10A of the golf ball 10 is not white, it is advantageous in capturing the outline clearly.
Also, the camera 22 may be an infrared camera.

The microphone 24 collects surrounding sounds and outputs them to the computer 28 as sound signals.
In this embodiment, the microphone 24 is provided to collect the hitting sound of the golf ball 10 and detect the start of movement of the golf ball 10 .
Note that the illustration of the microphone 24 is omitted in FIG. 3B in order to clarify the positional relationship between the camera 22 and a Doppler sensor 25, which will be described later.

The Doppler sensor 25 transmits the microwave as the transmitted wave W1 toward the golf ball 10 via the antenna section 252, and receives the reflected wave W2 reflected by the golf ball 10 via the antenna section 252. It detects the Doppler signal Sd.
A Doppler signal is a signal having a Doppler frequency Fd defined by the difference frequency F1-F2 between the frequency F1 of the transmission wave W1 and the frequency F2 of the reception wave W2.
Various commercially available Doppler sensors 25 can be used.
As the transmission wave W1, for example, a microwave of 24 GHz can be used, and the frequency of the transmission wave W1 is not limited as long as the Doppler signal Sd can be obtained.
The antenna portion 252 of the Doppler sensor 25 has directivity, and in the present embodiment, the antenna portion 252 is installed so that the directivity direction N thereof coincides with the target movement direction X (x-axis) of the golf ball 10. . That is, the Doppler sensor 25 is installed behind the movement start point P0 with the antenna section 252 facing the target movement direction X. As shown in FIG.
3A illustrates the behavior measuring device 20 from the x-axis direction, the illustration of the Doppler sensor 25 is omitted.

The computer 28 calculates behavior data of the golf ball 10 using information output from other components such as the camera 22 and the microphone 24 .
FIG. 5 is a block diagram showing the configuration of the computer 28. As shown in FIG.
The computer 28 includes a CPU 1802, a ROM 1804, a RAM 1806, a hard disk device 1808, a disk device 1810, a keyboard 1812, a mouse 1814, a display 1816, a printer 1818, an input/output interface 1820, etc., connected via an interface circuit and a bus line (not shown). have.
A ROM 1804 stores control programs and the like, and a RAM 1806 provides a working area.
The hard disk device 1808 stores a dedicated program (behavior measurement program) for measuring the behavior of the golf ball 10 .
A disk device 1810 records and/or reproduces data on recording media such as CDs and DVDs.
A keyboard 1812 and a mouse 1814 are for receiving operation input by the operator.
The display 1816 is for displaying data and the printer 1818 is for printing out data, and the display 1816 and the printer 1818 output data.
The input/output interface 1820 exchanges data with the camera 22, the microphone 24, the Doppler sensor 25, and the like.

A small information device such as a smart phone or a tablet may be used as the computer 28 .
In FIG. 3, the Doppler sensor 25, the camera 22, etc., and the computer 28 are connected by wiring, but communication between these devices may be performed by wireless communication.
In addition, when the computer 28 (including a smart phone, tablet, etc.) is equipped with the camera 22 and the microphone 24, the camera 22 and the microphone 24 of the computer 28 are used to capture images and collect sounds. good too. In this case, the number of devices constituting the behavior measuring device 20 can be reduced, and the labor and space required for installing the devices can be saved.

FIG. 6 is a block diagram showing the functional configuration of the behavior measuring device 20. As shown in FIG.
The behavior measurement device 20 is functionally composed of an arrangement detection means 202 , a movement start detection means 204 , an imaging means 206 , an imaging control means 208 and a behavior measurement means 210 .
Of these configurations, the imaging control means 208 and the behavior measurement means 210 are implemented by the CPU 1802 of the computer 28 described above executing the behavior measurement program.

The placement detection means 202 detects that the golf ball 10 has been placed at the movement start point.
When the movement start point of golf ball 10 is on tee 34 as in the present embodiment, placement detection means 202 detects that golf ball 10 has been placed on tee 34 .
In the present embodiment, the arrangement detection means 202 is implemented by the Doppler sensor 25, for example.
As described above, the Doppler sensor 25 is installed behind the movement start point P0 with the antenna section 252 facing the target movement direction X as shown in FIG. 3B. Therefore, the Doppler sensor 25 can measure the approach of the golf ball 10 along the x-axis (frequency change of Doppler signal).
Here, when the measurer I takes the address posture and performs a backswing, the golf club 32 moves substantially along the x-axis, so the Doppler sensor 25 detects the frequency change of the Doppler signal. When the measurer I performs a swing motion around the tee 34 (movement start position P0), it is predicted that the golf ball 10 is placed on the tee 34 . Therefore, by detecting the approach of the golf club 32 with the Doppler sensor 25, it is possible to detect that the golf ball 10 is placed on the tee 34, that is, placed at the movement start point.
That is, the golf ball 10, which is the golf ball 10, starts moving when it is hit by the golf club 32, which is the hitting tool. By detecting the start, it is detected that the golf ball 10 has been placed at the movement start point.

Alternatively, the placement detection means 202 may detect that the golf ball 10 has been placed at the movement start point by detecting a placement completion signal input from the outside.
That is, the measurer I may use the keyboard 1812 of the computer 28 to input that the golf ball 10 has been placed on the tee 34, or may input using a dedicated remote controller, switch, or the like.

Movement start detection means 204 detects that golf ball 10 has started movement.
In the present embodiment, the microphone 24 picks up the hitting sound of the golf ball 10 and detects the start of movement of the golf ball 10 . That is, the movement start detection means 204 detects the sound of hitting the golf ball 10 with the hitting tool, and detects that the golf ball 10 has started to move.
In addition, since various sounds such as the speaking voice of the measurer I are collected by the microphone 24, the frequency band indicating the hitting sound of the golf ball 10 is specified in advance, and the sound in this frequency band is detected by using voice recognition. It may be detected that the golf ball 10 has started to move by identifying that the sound is collected.

Further, the movement start detection means 204 is not limited to the microphone 24, and may be a passage detection sensor.
Specifically, the passage detection sensor is installed so that the detection area is in front of the installation position of the golf ball 10, and by detecting that the golf ball 10 or the golf club 32 has passed within the detection area, the golf ball is detected. It may be detected that 10 has started to move.
That is, a passage detection sensor whose detection area is on the movement path of the golf ball 10 may be used to detect that the golf ball 10 has started to move.
In this case, the detection area of the passage detection sensor is preferably set very close to the tee 34 so that the golf ball 10 can be photographed while it is positioned within the photographing area of the photographing means 206, which will be described later.

The photographing means 206 is arranged so that the movement start point P0 of the golf ball 10 is included in the photographing area, and photographs an image within the photographing area.
As described above, in this embodiment, the camera 22 constitutes the photographing means 206, and the photographing area H is set so as to include the tee 34, which is the movement start point P0.
The photographing unit 206 only needs to be able to photograph an image (still image) by photographing timing control by the photographing control unit 208, which will be described later.

The photographing control means 208 controls the photographing operation by the photographing means 206 based on the detection results of the arrangement detecting means 202 and the movement start detecting means 204 .
More specifically, when the placement detection unit 202 detects that the golf ball 10 is placed at the movement start point, the shooting control unit 208 generates an image of the golf ball 10 placed at the movement start point (first control the photographing means 206 so as to photograph the image). Further, when the movement start detection means 204 detects that the golf ball 10 has started to move, the image capturing control means 208 captures an image (second image) of the golf ball 10 after movement has started. Control means 206 . As a result, two images are obtained before and after the movement of the golf ball 10 (before and after launch).
When the golf ball 10 is photographed by the camera 22 , the golf ball 10 is irradiated with invisible light (infrared rays) by the infrared lamp 23 . That is, the photographing control means 208 controls the camera 22 to photograph an image of the golf ball 10 irradiated with invisible light by the invisible light irradiation means.

The behavior measurement unit 210 measures the golf ball 10 based on the first image, which is the image of the golf ball 10 placed at the movement start point P0, and the second image, which is the image of the golf ball 10 after movement has started. At least one of the moving direction, moving speed, rotation axis direction, and spin component of the ball 10 immediately after being hit is calculated.
The behavior measuring means 210 includes moving direction calculating means 2102 , rotational axis direction calculating means 2104 , moving speed calculating means 2106 and spin component calculating means 2108 . These are the behavior information of the golf ball 10, which are the moving direction, the rotation axis direction, the moving speed, and the spin component, respectively.

Here, a method of calculating behavior information by the behavior measuring means 210 will be described.
FIG. 8 is an explanatory diagram schematically showing an example of an image captured by the image capturing unit 206. As shown in FIG.
8A shows a first image, which is an image of the golf ball 10 placed at the movement start point, and FIG. 8B shows a second image, which is an image of the golf ball 10 after movement has started. is. Also, FIG. 8C overlaps FIGS. 8A and 8B after deleting elements other than the golf ball 10 from FIG. 8B.
FIGS. 9A and 9B are explanatory views schematically showing an example of an image captured by the image capturing means 206. FIG. 9A is the same view as FIG. 8A, and FIG. 9B is the direction (y FIG. 9C is an image when the golf ball 10 moves away from the camera 22 (in the negative y-coordinate direction).

The pattern 12 for behavior measurement of the golf ball 10 is visually recognized in the same color as the surface 10A of the golf ball 10 under visible light irradiation, and is almost invisible to the measurer I. On the other hand, on the image photographed under infrared irradiation, it becomes identifiable in a color different from that of the surface 10A.
Further, the design pattern 14 of the golf ball 10 is visually recognized in a color different from that of the surface 10A of the golf ball 10 under irradiation of visible light, and the measurer I can visually recognize the design pattern 14 . On the other hand, on the image photographed under the irradiation of invisible light, the design pattern 14 is difficult to identify because it has substantially the same color as the front surface 10A. Therefore, in the first image and the second image, only the behavior measurement pattern 12 is recognized on the surface 10A of the golf ball 10, and it is possible to prevent deterioration in behavior measurement accuracy due to erroneous detection of the design pattern 14. .

The behavior measurement means 210 captures the image captured by the camera 22 as digital data, performs image processing to eliminate unnecessary images such as the surrounding environment, and detects the circular contour area of the golf ball 10 . The behavior measurement means 210 calculates the center-of-gravity position and the diameter of the image (circular contour area) of the golf ball 10, and extracts the pattern 12 for behavior measurement from the inside of the contour area. If the shape of the behavior measurement pattern 12 is registered (stored) in the behavior measurement means 210 in advance, the behavior measurement pattern 12 can be extracted with high accuracy by pattern matching or the like.

[Calculation method of movement direction]
First, a method of calculating the moving direction θh in the vertical direction (on the xz plane) will be described.
As shown in FIG. 8C, a line segment L1 connecting the center point P1 of the golf ball 10 in the first image and the center point P2 of the golf ball 10 in the second image, and the center of the golf ball 10 in the first image. The direction of movement in the vertical direction (on the xz plane) can be specified by the angle θh formed by the line segment L2 passing through the point P1 and parallel to the ground G.
That is, the behavior measuring means 210 calculates the displacement direction between the position of the golf ball 10 in the first image and the position of the golf ball 10 in the second image as the movement direction.
If the optical axis of the camera 22 is not parallel to the ground G and is tilted in the vertical direction, the vertical movement direction θh is calculated after correcting the tilt.

Next, a method of calculating the moving direction θw in the horizontal direction (on the xy plane) will be described.
When the golf ball 10 moves while tilting in the horizontal direction with respect to the target movement direction X, the diameter of the golf ball 10 on the image differs before and after the start of movement, as shown in FIG.
In the example of FIG. 9, when the golf ball 10 moves toward the camera 22 as shown in FIG. 9B, the diameter R1 becomes larger than the diameter R0 of the golf ball 10 before the start of movement shown in FIG. 9A. (R1>R0), and when the golf ball 10 moves away from the camera 22 as shown in FIG. 9C, the diameter R2 becomes smaller (R2<R0).
Since the imaging magnification and angle of view of the camera 22 are known, the moving direction θw in the horizontal direction (on the xy plane) can be specified based on the difference in the diameter of the golf ball 10 before and after the start of movement.
For example, as shown in FIG. 9B, when the golf ball 10 moves toward the camera 22 (positive direction of the y coordinate), the larger the diameter of the golf ball 10 in the image, the greater the curve toward the camera 22. It will be. 9C, when the golf ball 10 moves away from the camera 22 (negative y-coordinate direction), the smaller the diameter of the golf ball 10 on the image, the greater the curve in the direction opposite to the camera 22. It means that
That is, the behavior measuring means 210 calculates the moving direction in the direction orthogonal to the shooting direction of the camera 22 based on the ratio of the diameters of the golf ball in the first image and the second image.

As another method of calculating the moving direction θw, stereo measurement using a plurality of cameras 22 may be performed.
FIG. 10 is an explanatory diagram showing another configuration example of the behavior measuring device 20. As shown in FIG.
In FIG. 10, two cameras 22A and 22B are installed so that an area including the movement start point P0 of the golf ball 10 is taken as an imaging area. Camera parameters such as the positions of the cameras 22A and 22B, the shooting direction (orientation), and the shooting magnification are specified in advance.
The cameras 22A and 22B take images of the golf ball 10 before and after it starts to move (before and after it is launched) at the same time.
Then, the position of the golf ball 10 on the images captured by the cameras 22A and 22B is specified, and the positions of the golf ball 10 in the three-dimensional space before and after the start of movement are specified using the above camera parameters. The moving direction θw of the golf ball 10 can be calculated from the difference in the positions of the golf ball 10 in the three-dimensional space before and after the start of movement.
That is, the position of the golf ball 10 in the three-dimensional space before the start of movement is specified based on the plurality of first images captured by the cameras 22A and 22B, respectively, and the position of the golf ball 10 is determined by the cameras 22A and 22B. The position of the golf ball 10 in the three-dimensional space after the start of movement is specified based on the plurality of captured second images, and the golf ball 10 moves based on the difference in the positions of the golf ball 10 in the three-dimensional space before and after the start of movement. You may make it calculate a direction.
In this manner, by using a plurality of cameras to capture images, the moving direction θw of the golf ball 10 can be calculated with higher accuracy.

[Method for calculating movement speed]
Next, a method for calculating the moving speed will be explained.
Calculation of the direction of movement and the direction of the axis of rotation described above can be performed using only two images before and after the start of movement. It is necessary to specify the elapsed time until the second image is taken.
To calculate the moving speed, first, the moving distance of the golf ball 10 is calculated. Since the imaging magnification of the camera 22 is known as described above, the ratio between the distance on the image and the distance on the real space is known, and the position (movement start point) of the golf ball 10 in the first image and the position of the golf ball 10 in the first image. The vertical component of the movement distance can be calculated from the distance from the position of the golf ball 10 in the second image.
Further, the horizontal component of the moving distance can be calculated from the vertical component of the moving distance and the moving direction θw in the horizontal direction (on the xy plane).
The linear movement distance of the golf ball 10 can be calculated from the vertical component and the horizontal component of the movement distance.

Next, the time when the golf ball 10 started to move is specified. When the movement start detecting means 204 is the microphone 24, the time when the hitting sound is detected by the microphone 24 can be set as the time when the golf ball 10 starts moving.
At this time, the value obtained by dividing the distance between the movement start point and the microphone 24 by the speed of sound is calculated as the delay time until the impact sound reaches the microphone 24, and this delay time is calculated from the time when the impact sound is detected by the microphone 24. You can deduct it.
At this time, a temperature sensor may be provided to detect the temperature around the movement start point, and the sound velocity value may be corrected using the temperature measured by the temperature sensor. That is, a value closer to the actual sound speed is calculated using a commonly used formula such as sound speed C = 331.5 + 0.61 t (t is temperature in degrees Celsius), and the time until the impact sound reaches the microphone 24 is calculated. You may As a result, the time at which the golf ball 10 started to move can be specified with higher accuracy.

By specifying the time when the second image was captured by the camera 22, the elapsed time from when the golf ball 10 started moving to when the second image was captured can be determined. The time when the second image was captured is the time when the capturing control means 208 instructed the camera 22 to capture the image or the capturing time of the second image recorded by the camera 22, and these are substantially the same.
By dividing the movement distance of the golf ball 10 calculated in this way by the elapsed time from when the golf ball 10 starts moving to when the second image is captured, the movement of the golf ball 10 can be calculated from the two images. Velocity can be calculated.

[Method for calculating rotation axis direction and spin component]
Next, a method of calculating the rotation axis direction and the spin component will be described.
As shown in FIG. 8, a golf ball 10 is provided with a pattern 12 for behavior measurement. The rotation axis direction of the golf ball 10 can be specified based on the position and direction of the behavior measurement pattern 12 of the golf ball 10 before and after the start of movement.
The direction of the rotation axis can be represented, for example, by the inclination of the rotation axis in the vertical direction and the inclination of the rotation axis in the horizontal direction, similarly to the movement direction. Further, the spin component of the golf ball 10 can be represented by a side spin component and a back spin component.

That is, the behavior measurement pattern 12 (hereinafter referred to as the first pattern) in the first image is the first three-dimensional virtual sphere Q (hereinafter referred to as the first virtual sphere Q) provided in the virtual space A. Map onto the surface. Also, the behavior measurement pattern 12 (hereinafter referred to as the second pattern) in the second image is mapped onto the surface of the second three-dimensional virtual sphere q (hereinafter referred to as the second virtual sphere q). . The behavior measurement means 210 obtains the rotation axis and the amount of rotation (rotation angle) around the rotation axis in the three-dimensional space by, for example, the image correlation method using the first virtual sphere Q and the second virtual sphere q.

In this case, the first virtual sphere Q is rotated three-dimensionally, and the three-dimensional rotation when the correlation coefficient between the first symbol and the second symbol on the second virtual sphere q becomes highest. The amount is the three-dimensional amount of rotation of the golf ball 10 between two times (the rotation axis in the three-dimensional space and the amount of rotation around the rotation axis (rotation angle)).
The three-dimensional rotation amount obtained by the image correlation method is divided in each axial direction shown in FIG. 3 and the like. Thereby, backspin and sidespin can be obtained.

The behavior measurement pattern 12 added to the golf ball 10 is preferably a pattern that appears on the image regardless of the direction in which the golf ball 10 rotates. In the present embodiment, the behavior measurement patterns 12 are provided at two opposite positions of the golf ball 10 .
That is, the golf ball 10 has a pattern that can be visually recognized from all directions, and the behavior measurement means 210 measures the rotation axis from the difference between the position and orientation of the pattern in the first image and the position and orientation of the pattern in the second image. Calculate direction.

FIG. 7 is a flowchart showing the procedure of processing by the behavior measuring device 20. As shown in FIG.
The behavior measurement device 20 first starts measurement by the Doppler sensor 25 (placement detection means 202) (step S400), and detects that the golf ball 10 has been placed at the movement start point (step S402: placement detection step). In the present embodiment, it is determined that the golf ball 10 has been placed at the movement start point when the start of the swing of the golf club 32 is detected by the Doppler signal.
When the golf ball 10 is positioned at the movement start point (step S402: Yes), the photographing control means 208 instructs the photographing means 206 to photograph an image, and the state where the golf ball 10 is at the movement start point is taken as the first image. Photographing is performed (step S404: first photographing step).
Next, the behavior measurement device 20 detects that the golf ball 10 has started to move by the movement start detection means 204 (step S406: movement start detection step).
When the golf ball 10 starts to move (step S406: Yes), the photographing control means 208 instructs the photographing means 206 to photograph an image, and the state in which the golf ball 10 is moving is photographed as a second image (step S408). : second photographing step). During this period, the Doppler signal is also continuously measured.
Subsequently, the behavior measurement means 210 calculates the behavior of the golf ball 10, such as the direction of movement, the direction of the axis of rotation, the speed of movement, and the spin component, from the Doppler signal and the two images (step S410: behavior measurement step).
Then, the calculated behavior information is displayed on the display 1816, printed paper, or the like (step S412), and the processing according to this flowchart ends.

As described above, in the golf ball 10 according to the embodiment, the pattern 12 for behavior measurement is identifiable only under irradiation of invisible light. The pattern 12 for behavior measurement is not visible on the I, which is advantageous in improving the design of the golf ball 10 .
Further, by applying any design such as the manufacturer's name, brand name, or logo of the golf ball 10 as the design design 14 visible under visible light, it is advantageous in further improving the design of the golf ball 10. Become. Further, since the design pattern 14 is identified in the same color as the surface 10A of the golf ball 10 under invisible light, only the behavior measurement pattern 12 is recognized on the surface 10A of the golf ball 10. It is advantageous in improving the accuracy of behavior measurement.

In the present embodiment, the behavior measurement symbol 12 and the design symbol 14 are given to the golf ball 10 in advance. A pattern 12 for behavior measurement may be added to a general golf ball 10 with a chisel.
In this case, for example, a sticker with behavior measurement pattern 12 is attached to surface 10A of golf ball 10, or a stamp using invisible ink is pressed onto surface 10A of golf ball 10. FIG.
That is, for example, prior to step S400 in FIG. 7, the surface 10A of the golf ball 10 appears to have the same color as the surface 10A under irradiation with visible light, and has a different color from the surface 10A under irradiation with invisible light of a predetermined wavelength. The pattern 12 for behavior measurement (first pattern) may be provided by arranging a visible material.
At this time, the surface 10A of the golf ball 10 to which the behavior-measuring pattern 12 (first pattern) is applied appears to have a color different from that of the surface 10A under irradiation of invisible light, and the color of the surface 10A under irradiation of visible light is different from that of the surface 10A. The design pattern 14 (second pattern) may be provided in advance by arranging a material visually recognized in the same color.

Further, a protective layer (not shown) may be provided on the surface 10A of the golf ball 10 provided with the behavior measurement pattern 12 (and the design pattern 14). As a result, the pattern for behavior measurement 12 and the pattern for design 14 can be prevented from disappearing, and the durability of the pattern can be improved. The material of the protective layer is preferably highly transparent to both visible light and invisible light.
That is, the surface of the behavior measurement pattern 12 (first pattern) may be further provided with a colorless and transparent protective layer under visible light irradiation and invisible light irradiation.

10 golf ball 10A surface 12 pattern for behavior measurement 14 pattern for design 17 infrared lamp 20 behavior measurement device 22 camera 32 golf club 23 infrared lamp 24 microphone 25 Doppler sensor 28 computer 202 arrangement detection means 204 movement start detection means 206 photographing means 208 photographing Control means 210 Behavior measurement means

Claims (6)

A golf ball having a first pattern on its surface,
The first pattern is used to measure the behavior of the golf ball, and is visible in the same color as the surface under irradiation with visible light, and is distinguishable in a different color from the surface under irradiation with invisible light of a predetermined wavelength. is formed by placing a material on the surface ,
A second pattern is further provided on the surface,
The second pattern is visually recognized in a color different from that of the surface under irradiation with visible light, and is identified as having the same color as the surface under irradiation with invisible light. formed,
A golf ball characterized by: The absorbance of the invisible light of the material forming the first pattern is higher than the absorbance of the invisible light of the surface by a predetermined value or more,
2. The golf ball of claim 1 , wherein: Further comprising a colorless and transparent protective layer on the surface of the first pattern under the visible light irradiation and the invisible light irradiation,
3. The golf ball according to claim 1, wherein: A golf ball behavior measuring device for measuring the behavior of the golf ball according to any one of claims 1 to 3 ,
a camera arranged to include the golf ball in an imaging area;
invisible light irradiation means for irradiating the golf ball with the invisible light;
a photographing control means for controlling the camera to photograph an image of the golf ball irradiated with the invisible light by the invisible light irradiation means;
behavior measuring means for calculating, based on the image, at least one of a direction of movement, a speed of movement, a direction of an axis of rotation, and a spin component of the golf ball immediately after hitting;
A golf ball behavior measuring device comprising: The camera is provided with a filter that selectively transmits the invisible light of the wavelength irradiated by the invisible light irradiation means,
5. The golf ball behavior measuring device according to claim 4 , wherein: A method of applying a pattern to a golf ball, comprising:
By disposing on the surface of the golf ball a material that appears to have the same color as the surface when irradiated with visible light and appears to have a different color from the surface when irradiated with invisible light of a predetermined wavelength. Giving the first pattern used for behavior measurement of
On the surface of the golf ball to which the first pattern is applied, there is a material that appears to have a different color from that of the surface under irradiation with visible light, and has the same color as that of the surface under irradiation with invisible light. By being arranged, the second pattern is given in advance,
A method of applying a pattern to a golf ball, characterized by:

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