Marked golf ball

Abstract

To provide a golf ball 2 capable of adjusting easily a swing trajectory.SOLUTION: A golf ball 2 has an assist mark 10 and a guide mark 12, The assist mark 10 is linear in a plane view. The guide mark 12 is distorted in a plane view. The guide mark 12 has an arrow shape as a whole. The guide mark 12 is seen linearly to a player swinging a golf club. The player moves the golf club head along a direction of the guide mark 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a golf ball, and more particularly to an improvement in marks on a golf ball. [Background technology]

[0002] A mark is printed on a golf ball. There are letter marks, graphic marks, marks that combine letters and graphics, etc. Typically, the brand of the golf ball is printed on the ball. The mark that represents the brand is called a main mark. Some golf balls have a side mark in addition to the main mark. Using the main mark or the side mark as a clue, players can identify the brand of the golf ball.

[0003] A mark according to the user may also be printed on the golf ball. This mark is called an own-name mark. Specific examples of the own-name mark include the user's name, company name, company emblem, and catchphrase. The own name allows the player to recognize his / her golf ball during a round. The own name can prevent a wrong shot. JP 2018-038575 A discloses a golf ball having a mark.

[0004] Japanese Patent Application Laid-Open No. 2008-022940 discloses a golf ball with so-called guide marks. When setting the golf ball, the player aligns the direction of the guide marks with the target direction. The player adjusts the swing trajectory while being guided by the guide marks. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP2018-038575A [Patent Document 2] JP2008-022940A Summary of the Invention [Problem to be solved by the invention]

[0006] A typical guide mark is linear. A golf ball has a spherical shape. Therefore, a guide mark that is linear in a plan view looks curved to a player who is swinging. This guide mark does not easily contribute to adjusting a swing trajectory.

[0007] An object of the present invention is to provide a golf ball whose swing trajectory is easy to adjust. [Means for solving the problem]

[0008] A golf ball according to the present invention has a guide mark that is distorted in a plan view and has a shape that can be illusorily perceived as non-distorted by a player in the player's sight line view when the player hits the golf ball with a golf club. Effect of the Invention

[0009] A player hitting a golf ball according to the present invention can easily adjust the swing trajectory. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a plan view showing a golf ball according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged view showing a part of a cross section taken along line II-II in FIG. [Diagram 3] FIG. 3 is a left side view of the golf ball of FIG. 1 along with a player and a golf club. [Figure 4] FIG. 4 is an enlarged view of the golf ball of FIG. 3 shown together with a tee. [Diagram 5] FIG. 5 is a view showing the golf ball of FIG. 1 as seen in the line of sight. [Figure 6]FIG. 6 is a view showing the golf ball of FIG. [Figure 7] FIG. 7 is a plan view showing a golf ball according to another embodiment of the present invention. [Figure 8] FIG. 8 is a plan view showing a golf ball according to still another embodiment of the present invention. [Figure 9] FIG. 9 is a plan view showing a golf ball according to still another embodiment of the present invention. [Figure 10] FIG. 10 is a plan view showing a golf ball according to still another embodiment of the present invention. [Figure 11] FIG. 11 is a left side view of the golf ball of FIG. 10 shown with a tee. [Figure 12] FIG. 12 is a plan view showing a golf ball according to still another embodiment of the present invention. [Figure 13] FIG. 13 is a left side view of the golf ball of FIG. 12 shown together with a tee. [Figure 14] FIG. 14 is a right side view of the golf ball of FIG. 12 shown with a tee. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings as appropriate.

[0012] The golf ball 2 shown in FIGS. 1 and 2 has a core 4, a cover 6, a paint layer 8, an assist mark 10, and a guide mark 12. The core 4 has a spherical shape. The material of the core 4 is a crosslinked rubber composition. The core 4 may have two or more layers. The cover 6 covers the core 4. The material of the cover 6 is a resin composition. The cover 6 may have two or more layers. The paint layer 8 covers the cover 6. The material of the paint layer 8 is a resin composition. In this embodiment, the paint layer 8 is transparent. The golf ball 2 may have an intermediate layer. The intermediate layer is located between the core 4 and the cover 6. Although not shown, the golf ball 2 has a large number of dimples on the surface. The diameter of the golf ball 2 is 40 mm or more and 45 mm or less. The mass of the golf ball 2 is 40 g or more and 50 g or less.

[0013] As shown in FIG. 2, the assist mark 10 is sandwiched between the cover 6 and the paint layer 8. The material of the assist mark 10 is a resin composition. This resin composition contains a base resin and a colorant. As described above, the paint layer 8 is transparent, so the assist mark 10 can be seen through the paint layer 8. The assist mark 10 may be formed on the paint layer 8.

[0014] Although not shown, like the assist mark 10, the guide mark 12 is also sandwiched between the cover 6 and the paint layer 8. The material of the guide mark 12 is a resin composition. This resin composition contains a base resin and a colorant. As described above, the paint layer 8 is transparent, so the guide mark 12 can be viewed through the paint layer 8. The guide mark 12 may be formed on the paint layer 8.

[0015] The golf ball 2 may have a main mark. The main mark represents the brand of the golf ball 2. The golf ball 2 may have a side mark. The side mark also represents the brand of the golf ball 2.

[0016] Fig. 1 shows a golf ball 2 placed on a tee on a teeing ground. Fig. 1 is a plan view of the golf ball 2. In other words, Fig. 1 shows the golf ball 2 as seen from above in the vertical direction. The left direction in Fig. 1 is the target direction. The player wants to hit the golf ball 2 in the target direction.

[0017] As is clear from FIG. 1, the assist mark 10 is linear in plan view. The assist mark 10 has a tapered head 14. In other words, the assist mark 10 has an arrow shape as a whole. The direction of the assist mark 10 (the direction of the arrow) is leftward in FIG. 1. In other words, the direction of the assist mark 10 coincides with the target direction.

[0018] As is clear from FIG. 1, the guide mark 12 is distorted in plan view. In this embodiment, the guide mark 12 is along a great circle of the golf ball 2. The great circle is the largest circle among the circles that can be drawn on the spherical surface of the golf ball 2. The diameter of the great circle is equal to the diameter of the golf ball 2. The golf ball 2 has an infinite number of great circles. Since the guide mark 12 is along a great circle, the shape of the guide mark 12 in plan view is generally an arc. The guide mark 12 has a front end 16, a midpoint 18, and a rear end 20. The guide mark 12 has a tapered head 22. In other words, the guide mark 12 has an arrow shape as a whole. Therefore, in this guide mark 12, the front end 16 can be distinguished from the rear end 20. This guide mark 12 has directionality. The golf ball 2 may have a guide mark that does not have directionality.

[0019] The two-dot chain line IL in Fig. 1 passes through the front end 16 and the rear end 20. This two-dot chain line IL extends in the left-right direction. In other words, the direction of this two-dot chain line IL coincides with the target direction. The left-right distance between the front end 16 and the midpoint 18 is equal to the left-right distance between the midpoint 18 and the rear end 20.

[0020] FIG. 3 is a left side view of the golf ball 2 of FIG. 1, together with the player 24 and the golf club 26. FIG. 3 also shows a ground 28 and a tee 30. The tee 30 stands above the ground 28. The golf ball 2 is on the tee 30. The player 24 grips the golf club 26. In this embodiment, the golf club 26 is a driver (W#1). The two-dot chain line SL in FIG. 3 is the sight line of the player 24. The sight line SL connects the eyes of the player 24 and the center of the golf ball 2. In FIG. 3, the symbol α is the angle of the sight line SL with respect to the vertical direction.

[0021] 4 is an enlarged view of the golf ball 2 of FIG.

[0022] Fig. 5 is a sight line view of the golf ball 2 of Fig. 1. Fig. 5 is a view of a player 24 while swinging a golf club 26. In Fig. 5, the guide mark 12 is linear. In other words, the guide mark 12 is perceived by the player 24 as being undistorted. Anamorphism is used for this guide mark 12.

[0023] The player 24, who has arrived at the teeing ground 28, sticks the tee 30 into the ground 28. The player 24 places the golf ball 2 on the tee 30. The player 24 adjusts the attitude of the golf ball 2 on the tee 30. Specifically, the player 24 adjusts the attitude of the golf ball 2 so that it satisfies the following (1) and (2). (1) When golf ball 2 is regarded as a globe, assist mark 10 is located at the North Pole. (2) The arrow on the assist mark 10 points toward the target. The assist mark 10 assists the player 24 in correctly setting the golf ball 2. The golf ball 2 after this setting is completed is shown in Figures 4 and 5. This setting may be performed on the ground instead of on the tee 30.

[0024] After this set, the player 24 swings the golf club 26. During the swing, the player 24 looks at the guide mark 12. The player 24 moves the club head along the direction of the guide mark 12. In other words, the player 24 adjusts the swing trajectory using the guide mark 12. The golf ball 2 that collides with the club head is launched toward the target direction. The guide mark 12 assists the player 24 in making a correct swing. The golf ball 2 having the guide mark 12 can contribute to the player 24 achieving a good score.

[0025] In FIG. 4, the symbol β represents the central angle of the guide mark 12 with respect to the vertical direction. The central angle β is measured at the midpoint 18 of the guide mark 12. As shown in FIG. 4, this central angle β coincides with the angle α of the line of sight SL of the player 24. Therefore, the player 24 can see the guide mark 12 straight ahead. As described above, since the guide mark 12 is along a great circle, the player 24 has the illusion that the guide mark 12 is linear. The central angle β may differ slightly from the angle α. The preferred central angle β is 5° to 40°.

[0026] The angle α varies depending on the physique and posture of the player 24 and the specifications of the golf club 26. The player 24 selects a golf ball 2 whose central angle β generally coincides with the angle α.

[0027] When the posture of the player 24 at address is incorrect, the guide mark 12 appears distorted by the player 24, even though the golf ball 2 that the player 24 should recognize as a straight line has been selected. For example, when the player 24 stands too close to the golf ball 2, the guide mark 12 appears to be a downward convex curve. When the knees of the player 24 are bent too much, the guide mark 12 appears to be an upward convex curve. The player 24, who sees the guide mark 12 as a curve, corrects his / her posture. This golf ball 2 can contribute to the player 24 learning the correct swing.

[0028] Fig. 6 shows the golf ball 2 as viewed from the direction of arrow A1 in Fig. 4. This arrow A1 is perpendicular to the line of sight SL. Fig. 6 shows the front end 16 and the rear end 20 of the guide mark 12. In Fig. 4, the symbol θ is the central angle between the front end 16 and the rear end 20. From the viewpoint of being able to assist the player 24 in making a correct swing, the central angle θ is preferably 90° or more, more preferably 110° or more, and particularly preferably 120° or more. The upper limit of the central angle is 360°.

[0029] The line of sight angle α of a typical player 24 when putting is approximately zero. When putting, the player 24 can hit the golf ball 2 toward the target direction while being assisted by the assist mark 10. The golf ball 2 does not have to have the assist mark 10.

[0030] 7 is a plan view showing a golf ball 32 according to another embodiment of the present invention. This golf ball 32 has an assist mark 34 and a guide mark 36. The specifications of this golf ball 32, except for the shape of the guide mark 36, are the same as those of the golf ball 2 shown in FIGS. 1 and 2.

[0031] The guide mark 36 has a first curve 38, a second curve 40, and a third curve 42. The first curve 38 includes a front end 44. The second curve 40 includes a midpoint 46. The third curve 42 includes a rear end 48. The overall shape of the three curves is generally a circular arc. The guide mark 36 has an arrow shape as a whole. The guide mark 36 has a directional property.

[0032] The guide mark 36 may be perceived as non-distorted by the player during the swing. Anamorphism is used for the guide mark 36. The player moves the club head along the direction of the guide mark 36. The golf ball 32 that collides with the club head is launched toward the target direction. The guide mark 36 assists the player in making a correct swing. The guide mark 36 may further contribute to the player's learning of a correct swing. The central angle β (see FIG. 4) of the guide mark 36 with respect to the vertical direction is preferably 5° or more and 40° or less. The central angle θ (see FIG. 6) between the front end 44 and the rear end 48 of the guide mark 36 is preferably 90° or more, more preferably 110° or more, and particularly preferably 120° or more. The upper limit of the central angle θ is 360°.

[0033] 8 is a plan view showing a golf ball 50 according to still another embodiment of the present invention. This golf ball 50 has an assist mark 52 and a guide mark 54. The specifications of this golf ball 50, except for the shape of the assist mark 52, are the same as those of the golf ball 2 shown in FIGS. 1 and 2.

[0034] The assist mark 52 is circular. The player adjusts the posture of the golf ball 50 so that the assist mark 52 is located at the north pole when the golf ball 50 is considered to be a globe. The player further adjusts the posture of the golf ball 50 so that the arrow of the guide mark 54 points in the target direction. The player then performs a swing while being guided by the guide mark 54. During the swing, the player has the illusion that the guide mark 54 is not distorted. This golf ball 50 assists the player in making a correct swing. This golf ball 50 can further contribute to the player's learning to make a correct swing.

[0035] 9 is a plan view showing a golf ball 56 according to still another embodiment of the present invention. This golf ball 56 has an assist mark 58 and a guide mark 60. The specifications of this golf ball 56, except for the shape of the assist mark 58, are the same as those of the golf ball 2 shown in FIGS. 1 and 2.

[0036] The assist mark 58 has a circular portion 62 and an arrow portion 64. The player adjusts the posture of the golf ball 56 so that the circular portion 62 is located at the north pole when the golf ball 56 is considered to be a globe. The player further adjusts the posture of the golf ball 56 so that the arrow portion 64 points in the target direction. The player then performs a swing while being guided by the guide mark 60. During the swing, the player has the illusion that the guide mark 60 is not distorted. This golf ball 56 assists the player in making a correct swing. This golf ball 56 can further contribute to the player's learning to make a correct swing.

[0037] Fig. 10 is a plan view showing a golf ball 66 according to still another embodiment of the present invention, and Fig. 11 is a left side view thereof. This golf ball 66 has an assist mark 68, a first guide mark 70, and a second guide mark 72. The specifications of this golf ball 66 other than the guide marks are the same as those of the golf ball 2 shown in Figs. 1 and 2.

[0038] As is clear from Fig. 10, the first guide mark 70 is distorted in a plan view. In this embodiment, the first guide mark 70 follows a great circle of the golf ball 66. The shape of the first guide mark 70 is generally a circular arc. The first guide mark 70 has a front end 74, a midpoint 76, and a rear end 78. The first guide mark 70 has a tapered head 80. The first guide mark 70 has directionality.

[0039] The first guide mark 70 is perceived as being linear (undistorted) by the player during the swing. Anamorphosis is used for the first guide mark 70. The player moves the club head along the direction of the first guide mark 70. The golf ball 66 that collides with the club head is launched toward the target direction. The first guide mark 70 assists the player in making a correct swing. The first guide mark 70 can further contribute to the player's learning of a correct swing. The central angle β1 of the first guide mark 70 with respect to the vertical direction (see FIG. 11) is preferably 5° or more and 40° or less. The central angle θ1 between the front end 74 and the rear end 78 of the first guide mark 70 is preferably 90° or more, more preferably 110° or more, and particularly preferably 120° or more. The upper limit of the central angle θ1 is 360°.

[0040] The second guide mark 72 is distorted in a plan view. The degree of curvature of the second guide mark 72 is smaller than that of the first guide mark 70. In this embodiment, the second guide mark 72 is along a great circle different from the great circle of the first guide mark 70. The shape of the second guide mark 72 is generally a circular arc. The second guide mark 72 has a front end 82, a midpoint 84, and a rear end 86. The second guide mark 72 has a tapered head 88. The second guide mark 72 is directional.

[0041] The second guide mark 72 is perceived as being linear (undistorted) by the player during the swing. Anamorphism is used for the second guide mark 72. The player moves the club head along the direction of the second guide mark 72. The golf ball 66 that collides with the club head is launched toward the target direction. The second guide mark 72 assists the player in making a correct swing. The second guide mark 72 can further contribute to the player's learning of a correct swing. The central angle β2 (see FIG. 11) of the second guide mark 72 with respect to the vertical direction is preferably 5° or more and 40° or less. The central angle β2 is smaller than the central angle β1. The central angle θ2 between the front end 82 and the rear end 86 of the second guide mark 72 is preferably 90° or more, more preferably 110° or more, and particularly preferably 120° or more. The upper limit of the central angle θ2 is 360°.

[0042] Since the central angle β1 is large, the first guide mark 70 is suitable for a swing in which the angle α1 of the line of sight SL1 is large. For example, the first guide mark 70 is suitable for a swing with a driver (W#1). From this viewpoint, it is particularly preferable that the central angle β1 be equal to or greater than 20° and equal to or less than 35°.

[0043] Since the central angle β2 is small, the second guide mark 72 is suitable for a swing in which the angle α2 of the line of sight SL2 is small. For example, the second guide mark 72 is suitable for a swing with an iron golf club. From this viewpoint, it is particularly preferable that the central angle β2 be equal to or greater than 10° and equal to or less than 25°.

[0044] From the viewpoint of applicability to swings with various golf clubs, the difference (β1-β2) between the central angle β1 and the central angle β2 is preferably 5° or more, more preferably 10° or more, and particularly preferably 13° or more. The difference (β1-β2) is preferably 25° or less. The golf ball 66 may have three or more guide marks each having a different central angle β.

[0045] Fig. 12 is a plan view showing a golf ball 90 according to still another embodiment of the present invention, Fig. 13 is a left side view thereof, and Fig. 14 is a right side view thereof. This golf ball 90 has an assist mark 92, a first guide mark 94, and a second guide mark 96. The specifications of this golf ball 90 other than the guide marks are the same as those of the golf ball 2 shown in Figs. 1 and 2.

[0046] As is clear from Fig. 12, the first guide mark 94 is distorted in a plan view. In this embodiment, the first guide mark 94 follows the great circle of the golf ball 90. The shape of the first guide mark 94 is generally a circular arc. The first guide mark 94 has a front end 98, a midpoint 100, and a rear end 102. The first guide mark 94 has a tapered head 104. The first guide mark 94 has directionality.

[0047] The first guide mark 94 is perceived as being linear (undistorted) by the player during the swing. Anamorphosis is used for the first guide mark 94. The player moves the club head along the direction of the first guide mark 94. The golf ball 90 that collides with the club head is launched toward the target direction. The first guide mark 94 assists the player in making a correct swing. The first guide mark 94 can further contribute to the player's learning of a correct swing. The central angle β1 of the first guide mark 94 with respect to the vertical direction (see FIG. 13) is preferably 5° or more and 40° or less. The central angle θ1 between the front end 98 and the rear end 102 of the first guide mark 94 is preferably 90° or more, more preferably 110° or more, and particularly preferably 120° or more. The upper limit of the central angle θ1 is 360°.

[0048] The second guide mark 96 is located on the opposite side of the first guide mark 94 across the assist mark 92. The second guide mark 96 is distorted in a plan view. The degree of curvature of the second guide mark 96 is smaller than that of the first guide mark 94. In this embodiment, the second guide mark 96 is along a great circle different from the great circle of the first guide mark 94. The shape of the second guide mark 96 is approximately a circular arc. The second guide mark 96 has a front end 106, a midpoint 108, and a rear end 110. The second guide mark 96 has a tapered head 112. The second guide mark 96 is directional. The direction of the second guide mark 96 is opposite to the direction of the first guide mark 94.

[0049] The second guide mark 96 is perceived as being linear (undistorted) by the player during the swing. Anamorphosis is used for the second guide mark 96. The player moves the club head along the direction of the second guide mark 96. The golf ball 90 that collides with the club head is launched toward the target direction. The second guide mark 96 assists the player in making a correct swing. The second guide mark 96 can further contribute to the player's learning of a correct swing. The central angle β2 (see FIG. 14) of the second guide mark 96 with respect to the vertical direction is preferably 5° or more and 40° or less. The central angle β2 is smaller than the central angle β1. The central angle θ2 between the front end 106 and the rear end 110 of the second guide mark 96 is preferably 90° or more, more preferably 110° or more, and particularly preferably 120° or more. The upper limit of the central angle θ1 is 360°.

[0050] Since the central angle β1 is large, the first guide mark 94 is suitable for a swing with a large line of sight angle α1. For example, the first guide mark 94 is suitable for a swing with a driver (W#1). From this viewpoint, it is particularly preferable that the central angle β1 be equal to or greater than 20° and equal to or less than 35°. As shown in FIG. 12, the golf ball 90 has the letters "W#1." These letters are located near the first guide mark 94.

[0051] Since the central angle β2 is small, the second guide mark 96 is suitable for a swing with a small line of sight angle α2. For example, the second guide mark 96 is suitable for a swing with an iron golf club. From this viewpoint, it is particularly preferable that the central angle β2 is equal to or greater than 10° and equal to or less than 25°. As shown in FIG. 12, the golf ball 90 has the letters "I#7". These letters are located near the second guide mark 96.

[0052] From the standpoint of applicability to swings with various golf clubs, the difference (β1-β2) between the central angle β1 and the central angle β2 is preferably 5° or more, more preferably 10° or more, and particularly preferably 13° or more. The difference (β1-β2) is preferably 25° or less. Golf ball 90 may have three or more guide marks each having a different central angle β.

[0053] The letters "W#1" inform the player of the applicable golf club number. Prior to a shot with a driver (first golf club), the player selects a golf ball bearing the letters "W#1". The player then selects a first guide mark 94 with reference to the letters "W#1". The player sets the golf ball 90 so that the arrow of the first guide mark 94 points in the direction of the target.

[0054] The letters "I#7" inform the player of the applicable golf club number. Prior to a shot with a No. 7 iron club (second golf club), the player selects a golf ball bearing the letters "I#7". The player then selects a second guide mark 96 with reference to the letters "I#7". The player sets the golf ball 90 so that the arrow of the second guide mark 96 points in the target direction. The direction of the golf ball 90 at this time is opposite to the direction of a shot with a driver.

[0055] As shown in Fig. 12, the assist mark 92 has a shape of a double-headed arrow. The assist mark 92 is useful for adjusting the position of the golf ball 90 prior to a shot with a driver (Fig. 13). Furthermore, the assist mark 92 is useful for adjusting the position of the golf ball 90 prior to a shot with an iron (Fig. 14).

[0056] The golf ball may have other letters to inform the player of the number of the golf club to be applied. Examples of other letters include "W#2", "W#3", "W#4", "W#5", "W#6", "W#7", "W#8", "W#9", "U#1", "U#2", "U#3", "U#4", "U#5", "U#6", "U#7", "U#8", "U#9", "I#1", "I#2", "I#3", "I#4", "I#5", "I#6", "I#7", "I#8", "I#9", "PW", "AW", "SW" and "P". The golf ball may have letters indicating the loft angle of the golf club.

[0057] The following items disclose embodiments of the present golf ball. As long as the effects of the present invention are achieved, the scope of the present invention is not to be construed as being limited by the description of the embodiments.

[0058] [Item 1] A golf ball having a guide mark, A golf ball in which the guide mark has a shape that is distorted in a plan view and can be illusorily perceived as non-distorted by a player in the player's sight line view when the player hits the golf ball with a golf club.

[0059] [Item 2] 2. The golf ball according to claim 1, wherein the guide mark has a shape that is curved when viewed in a plan view and linear when viewed in the line of sight.

[0060] [Item 3] 3. The golf ball according to claim 1, wherein a central angle β of the guide mark with respect to the vertical direction is equal to or greater than 5° and equal to or less than 40°.

[0061] [Item 4] 4. The golf ball according to claim 1, wherein a central angle θ between the front end and the rear end of the guide mark is 90° or greater.

[0062] [Item 5] 5. The golf ball according to claim 1, wherein the guide mark has a directionality.

[0063] [Item 6] 6. The golf ball according to claim 1, wherein the guide mark is aligned along a great circle of the sphere of the golf ball.

[0064] [Item 7] 7. The golf ball according to claim 1, further comprising an assist mark indicating the position of the golf ball when the golf ball is set by the player.

[0065] [Item 8] A golf ball having a first guide mark and a second guide mark, the first guide mark has a shape that is distorted in a plan view and that can be illusorily perceived as non-distorted by a player when viewed in a first line of sight direction of the player when the player hits the golf ball with a first golf club; The golf ball has a shape in which the second guide mark is distorted in a plan view and can be illusorily perceived as non-distorted by the player in the second line of sight view when the player hits the golf ball with a second golf club.

[0066] [Item 9] the first guide mark has a shape that is curved in a plan view and linear in a view in the first line of sight, 9. The golf ball according to claim 8, wherein the second guide mark has a shape that is curved in a plan view and linear when viewed in the second line of sight.

[0067] [Item 10] The central angle β1 of the first guide mark with respect to the vertical direction is equal to or greater than 5° and equal to or less than 40°, The central angle β2 of the second guide mark with respect to the vertical direction is equal to or greater than 5° and equal to or less than 40°, 10. The golf ball according to claim 8, wherein the angle β1 is greater than the angle β2.

[0068] [Item 11] 11. The golf ball according to claim 10, wherein the angle β1 is equal to or greater than 20° and equal to or less than 35°, and the angle β2 is equal to or greater than 10° and equal to or less than 25°.

[0069] [Item 12] 12. The golf ball according to claim 10, wherein the difference between the angle β1 and the angle β2 (β1-β2) is 5° or greater.

[0070] [Item 13] The central angle θ1 between the front end and the rear end of the first guide mark is 90° or more, 13. The golf ball according to claim 8, wherein a central angle θ2 between the front end and the rear end of the second guide mark is 90° or greater.

[0071] [Item 14] 14. The golf ball according to claim 8, wherein the first guide mark has a directional property, and the second guide mark has a directional property.

[0072] [Item 15] the first guide mark is aligned along a great circle of the golf ball; 15. The golf ball according to claim 8, wherein the second guide mark is along another great circle of the sphere.

[0073] [Item 16] 16. The golf ball according to claim 8, further comprising an assist mark indicating the position of the golf ball when the golf ball is set by the player. [Industrial Applicability]

[0074] The golf ball according to the present invention is suitable for playing on a golf course, practicing at a driving range, and the like. [Explanation of symbols]

[0075] 2. Golf ball 10. Assist marks 12 Guide mark 14. Assist Mark's Head 16 Front end of guide mark 18. Guide mark midpoint 20 Guide mark rear end 22 Guide mark head 24... Players 26. Golf club 28. Ground 30. T 32. Golf ball 34. Assist Mark 36 Guide mark 38···First curve of guide mark 40···Second curve of guide mark 42 Guide mark third curve 44 Front end of guide mark 46 Guide mark midpoint 48 Guide mark rear end 50···Golf balls 52. Assist Mark 54 Guide mark 56. Golf ball 58. Assist Mark 60 Guide mark 62 Circular part of assist mark 64. Assist mark arrow 66···Golf ball 68. Assist Mark 70 First guide mark 72 Second guide mark 90···Golf balls 92. Assist Mark 94 First guide mark 96 Second guide mark

Claims

1. A golf ball having an assist mark and a guide mark, When the golf ball is regarded as a globe and the assist mark is located at the north pole, the central angle β of the guide mark with respect to the vertical direction is 5° or more and 40° or less, The golf ball has a guide mark having a shape that is curved in a plan view and can be illusorily perceived as a straight line by a player when the player hits the golf ball with a golf club in the line of sight of the player so that the angle α of the line of sight with respect to the vertical direction coincides with the central angle β.

2. 2. The golf ball according to claim 1, wherein the central angle .theta. between the front end and the rear end of the guide mark is 90.degree. or greater.

3. 3. The golf ball according to claim 1, wherein the guide marks have a directional property.

4. 4. The golf ball according to claim 1, wherein the guide mark is aligned along a great circle of the sphere of the golf ball.

5. A golf ball having an assist mark, a first guide mark, and a second guide mark, When the assist mark is located at the North Pole when the golf ball is regarded as a globe, a central angle β1 of the first guide mark with respect to the vertical direction is 5° or more and 40° or less, a central angle β2 of the second guide mark with respect to the vertical direction is 5° or more and 40° or less, and the angle β1 is larger than the angle β2, the first guide mark has a shape that is curved in a plan view and that can be illusorily perceived as linear by a player when viewed in a first line of sight direction of the player when the player hits the golf ball with a first golf club so that an angle α1 of the line of sight with respect to the vertical direction of the line of sight coincides with the central angle β1; The golf ball has a second guide mark having a shape that is curved in a plan view and that can be illusorily perceived as straight by a player when viewed in the second line of sight direction of the player when the player hits the golf ball with a second golf club so that the angle α2 of the line of sight with respect to the vertical direction coincides with the central angle β2.

6. 6. The golf ball according to claim 5, wherein the angle β1 is equal to or greater than 20° and equal to or less than 35°, and the angle β2 is equal to or greater than 10° and equal to or less than 25°.

7. 7. The golf ball according to claim 5, wherein the difference between the angle β1 and the angle β2 (β1-β2) is 5° or greater.

8. The central angle θ1 between the front end and the rear end of the first guide mark is 90° or more, 8. The golf ball according to claim 5, wherein a central angle θ2 between the front end and the rear end of the second guide mark is equal to or greater than 90°.

9. 9. The golf ball according to claim 5, wherein the first guide mark has a directional property, and the second guide mark has a directional property.

10. the first guide mark is aligned along a great circle of the golf ball; 10. The golf ball according to claim 5, wherein the second guide mark is along another great circle of the sphere.

Images