JP2012198256A - Progressive refractive power lens and method for designing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a progressive refractive power lens which is suitable for a user with high use frequency of intermediate distance.SOLUTION: In a progressive refractive power lens 10 for spectacles having a far focal part 11, a near focal part 12, and an intermediate part 13 with different visual power, the intermediate part 13 is provided with: a first area 131 which is connected to the far focal part 11, and includes a first visual power gradient D1; a second area 132 which is connected the near focal part 12, and includes a second visual power gradient D2; and a third area 133 which is located between the first area 131 and the second area 132, and includes a third visual power gradient D3. The first visual power gradient D1, the second visual power gradient D2, and the third visual power gradient D3 satisfy the following condition: (1) |D3|<MIN(|D1|,|D2|) where MIN is a function showing the minimum value.

Description

  The present invention relates to a progressive power lens for spectacles and a design method thereof.

  In Patent Document 1, in a progressive multifocal lens, the gradient of the addition power along the central reference line of the progressive multifocal lens is made sufficiently gentle, and astigmatism on the line is kept small. A progressive multifocal lens with a wide and good field of view in the middle area and less image fluctuations by making the width of the clear vision area (part of astigmatism less than 0.5 diopters) significantly smaller than before. It is described to realize. In eyeglasses using the lens, the eye point at the time of frame insertion processing is set at a position 5 mm to 15 mm away from the distance center on the central reference line in the direction of the near vision center, thereby allowing visual work at medium and near distances. It is described that glasses suitable for the above are realized.

  Patent Document 2 describes that a progressive multifocal lens that secures a wide intermediate portion and a near vision portion and places little emphasis on near vision and intermediate vision is provided. Therefore, the distance power measurement position F is 14 mm above the geometric center O of the lens, the near power measurement position N is 17.5 mm below the geometric center O of the lens, and 2.5 mm on the inner side of the nose. An eye point position E, which is a position through which the line of sight passes when the lens wearer looks in front, is provided at a position 1.0 mm in the horizontal nose side of the geometric center O, and the position of the distance power measurement position F on the lens. When the horizontal right side is set to 0 ° as the reference direction, a substantially fan-shaped region Df extending from the 30 ° direction to the 150 ° direction is defined as the far vision region, and astigmatism in this region is 0.50 diopter or less. It is described to do. Further, the main gaze line that divides the lens into the “nose side portion” and the “ear side portion” through the three points of the distance power measurement position F, the eye point position E, and the near power measurement position N is the main focus line. It is described that two surface portions divided by the line of sight are configured to be asymmetric in the horizontal direction with respect to the main line of sight.

  Patent Document 3 describes that a progressive multifocal lens that reduces unnecessary lens astigmatism without a functional loss of distance and groove width over the intermediate vision region and the near vision region and a method for manufacturing the same are described. Has been. Therefore, the progressive multifocal lens of Patent Document 3 includes a first progressive refraction surface having a maximum and localized at least one region of unnecessary astigmatism and a first refractive addition force, a maximum, And having at least one region consisting of localized unwanted astigmatism and a second progressive refractive surface having a second refractive addition force. In this progressive multifocal lens, the first progressive refractive surface and the second progressive refractive surface are arranged in relation to each other so that a part or all of unnecessary astigmatism is displaced. The refractive addition power of the lens is the sum of the first refractive addition power and the second refractive addition power.

JP-A-62-1617 JP-A-08-286156 JP 2000-155294 A

  In recent years, opportunities to work while gazing at the display of a personal computer are increasing. The distance from the eyeball to the display is 60 cm to 80 cm, which is intermediate between distance vision and near vision, and there is a demand for a spectacle lens that is easy to see objects not only in the distance and near vision areas.

One aspect of the present invention is a progressive power lens for spectacles having a distance portion and a near portion having different visual powers, and an intermediate portion located between the distance portion and the near portion, wherein the intermediate portion Is connected to the distance portion, the first region having the first visual power gradient D1, the second region having the second visual power gradient D2, which is connected to the near portion, and the first region And a third region located between the second region and a third region having a third visual power gradient D3, the first visual power gradient D1, the second visual power gradient D2 and the third visual power gradient D3 are progressive power lenses that satisfy the following conditions.
| D3 | <MIN (| D1 |, | D2 |) (1)
However, MIN is a function indicating a minimum value.

  In this progressive-power lens, the visual power gradient D3 is higher than the visual power gradients D1 and D2 of the upper and lower first regions and the second region at the intermediate portion connecting the distance portion and the near portion having different visual powers. Includes a small third region. Therefore, by viewing the object through the third region, it is possible to obtain an image with little change in magnification or fluctuation due to a change in the visual power, and it is possible to provide a progressive power lens that allows easy viewing of the object even at an intermediate distance.

  The third region preferably includes a fitting point. For users who often watch an object at an intermediate distance, it is possible to select a fitting point for the frequently used intermediate vision portion.

The first to third regions can be provided by appropriately designing the progressive surface of either the object side surface or the eyeball side surface. The intermediate object side surface includes a first progressive surface whose surface refractive power changes between coordinates P1 and P2 along the main gaze line, and the intermediate eyeball side surface is the main gaze line. A progressive power lens that includes a second progressive surface whose surface refractive power varies between the coordinate P3 and the coordinate P4 along which the coordinates P1, P2, P3, and P4 are different from each other and satisfies the following conditions is effective.
P1> P2 (2)
P3> P4 (3)

  Here, a large coordinate along the main gazing line means that the position of the coordinate is close to the distance portion. And that the coordinate along the main gaze line is small means that the position of the coordinate is close to the near-use part.

  By providing progressive surfaces whose surface refractive power changes in different ranges along the main gaze line on the object side surface and the eyeball side surface, that is, the first progressive surface and the second progressive surface, respectively. It is easy to design a progressive-power lens having an intermediate portion including the first to third regions, and to easily correct various aberrations.

The first progressive surface and the second progressive surface may be surfaces that impart a visual power gradient having the same tendency. In this case, the coordinates P1, P2, P3, and P4 further satisfy any one of the following conditions (4) and (5), and the third coordinate is in the region between the first progressive surface and the second progressive surface. Can be provided.
P2> P3 (4)
P1 <P4 (5)

  By selecting one of the conditions (4) and (5), the object-side surface and the eyeball-side surface are surface-refracted so as to give the same visual power gradient to different positions along the main line of sight. Includes progressive surfaces with varying forces. When the condition (4) is adopted, a third region can be provided between the coordinates P2 and the coordinates P3. When the condition (5) is employed, a third region can be provided between the coordinates P4 and the coordinates P1.

The first progressive surface and the second progressive surface may be reverse progressive surfaces provided with a visual power gradient having a reverse tendency. In this case, the coordinates P1, P2, P3, and P4 further satisfy any of the following conditions, and the second progressive surface or the first progressive surface is the surface refraction of the first progressive surface or the second progressive surface. The third region can be provided by canceling the force gradient.
P1> P3 and P2 <P4 (6)
P1 <P3 and P2> P4 (7)

  Another aspect of the present invention is a pair of spectacles having the progressive-power lens described above and a spectacle frame to which the progressive-power lens is attached.

  Furthermore, another different aspect of the present invention is a progressive power for glasses having a distance portion and a near portion having different visual powers, and an intermediate portion located between the distance portion and the near portion. This is a lens design method. In this design method, the intermediate portion is connected to the distance portion, the first region having the first visual power gradient D1, and the second region is connected to the near portion and has the second visual power gradient D2. Providing a region and a third region located between the first region and the second region, the third region having a third visual power gradient G3, The visual power gradient G1, the second visual power gradient D2, and the third visual power gradient D3 satisfy the above condition (1).

  One of the other different aspects of the present invention is that progressive refraction includes designing an object-side surface, designing an object-side surface, and designing an eyeball-side surface before or after or simultaneously. This is a design method for a force lens. Designing the object-side surface is the first progressive surface included in the intermediate portion, and the surface refractive power changes between the coordinate P1 along the main gazing line and the coordinate P2 smaller than the coordinate P1. Designing one progressive surface, and designing the eyeball-side surface is a second progressive surface included in the intermediate portion, and is a coordinate P4 smaller than the coordinate P3 from the coordinate P3 along the main line of sight Design a second progressive surface whose surface refractive power varies so as to give a visual power gradient having the same tendency as the first progressive surface, and coordinates P1, P2, P3 and P4 satisfy the above condition ( Either 4) or (5) is satisfied.

  One of the other different aspects of the present invention is that progressive refraction includes designing an object-side surface, designing an object-side surface, and designing an eyeball-side surface before or after or simultaneously. The force lens design method is to design the object side surface between the coordinates P1 along the main gaze line and coordinates P2 smaller than the coordinates P1. Designing the first progressive surface whose surface refractive power changes includes designing the eyeball-side surface as a second progressive surface included in the intermediate portion, and coordinates P3 along the main line of sight To design a second progressive surface whose surface refractive power changes so as to give a visual power gradient opposite to the first progressive surface between coordinates P4 smaller than coordinate P3, and coordinates P1, P2, P3 and P4 satisfy either of the above conditions (6) and (7).

  Still another aspect of the present invention is a method for manufacturing a progressive-power lens, which includes manufacturing a progressive-power lens designed by the above-described design method.

The perspective view which shows an example of spectacles. FIG. 2A is a plan view schematically showing one of the progressive-power lenses, and FIG. 2B is a cross-sectional view thereof. The figure which shows the power distribution along the outer surface of the progressive-power lens of Example 1, an inner surface, and the visual main gaze line. The figure which shows astigmatism distribution of the outer surface (FIG. 4 (a)), inner surface (FIG. 4 (b)), and visual observation (FIG. 4 (c)) of the progressive-power lens of Example 1. FIG. The figure which shows the average frequency distribution of the outer surface (FIG. 5 (a)), inner surface (FIG. 5 (b)), and visual observation (FIG. 5 (c)) of the progressive-power lens of Example 1. FIG. 6A is a diagram showing an outline of a progressive-power lens including an intermediate portion having a continuous power gradient, and FIG. 6B is a diagram showing an overview of a progressive-power lens including an intermediate portion having a discontinuous power gradient. . The figure which shows the frequency distribution along the outer surface of the progressive-power lens of Example 2, an inner surface, and the visual main gaze line of visual observation. The figure which shows the power distribution along the outer surface of the progressive-power lens of Example 3, an inner surface, and the visual main gaze line. The figure which shows the power distribution along the outer surface of the progressive-power lens of Example 4, an inner surface, and the visual main gaze line. The figure which shows the frequency distribution along the outer surface of the progressive-power lens of Example 5, an inner surface, and the visual main gaze line of visual observation. The flowchart which shows the outline | summary of a design and manufacturing process.

  FIG. 1 is a perspective view showing an example of eyeglasses. FIG. 2A schematically shows one lens of one progressive-power lens according to the embodiment of the present invention in a plan view. FIG. 2B schematically shows one of the progressive-power lenses in a cross-sectional view.

  In this example, as viewed from the user side (user side, wearer side, eyeball side), the left side is described as left and the right side is described as right. The spectacles 1 includes a pair of left and right spectacle lenses 10L and 10R for the left eye and right eye, and a spectacle frame 20 on which the lenses 10L and 10R are respectively mounted. The spectacle lenses 10L and 10R are progressive multifocal lenses (progressive power lenses), respectively. The basic shape of the lenses 10L and 10R is a meniscus lens convex on the object side. Therefore, each of the lenses 10L and 10R includes an object side surface (convex surface, also referred to as an outer surface) 19A and an eyeball side (user side) surface (a concave surface, also referred to as an inner surface) 19B.

  FIG. 2A shows the right-eye lens 10R. This lens 10 </ b> R is a visual field part for viewing an object at a long distance (for far vision) at a location above (in the direction where the coordinates along the main gazing line are large, the direction of the distance portion along the main gazing line). A certain distance portion 11 is included and is located at a lower position (in the direction of the near portion along the main gazing line in the direction in which the coordinates along the main gazing line are smaller) than the distance portion 11 (visual power and refractive power). ) Includes a near portion 12 that is a visual field portion for viewing an object at a short distance (for near vision). Furthermore, the lens 10R includes an intermediate portion (a portion for intermediate vision, a progressive portion, a progressive zone) 13 that connects the distance portion 11 and the near portion 12 so that the visual power (refractive power) changes. . The lens 10 </ b> R includes a main gaze line 14 that connects a position on the lens that is the center of the field of view when performing far vision, intermediate vision, and near vision. In the spectacle lens 10 </ b> R, the fitting point FP, which is a reference point on the lens when the outer periphery is shaped and framed in accordance with the frame, is located at the intermediate portion 13.

  Hereinafter, the fitting point FP is set as the coordinate origin of the lens, the horizontal coordinate of the horizontal reference line X passing through the fitting point FP is set as the x coordinate, and the coordinate on the main gazing line 14 is set as the y coordinate. The main gaze line 14 bends to the nose side after passing the fitting point FP with respect to the vertical reference line (main meridian) Y passing through the fitting point FP. The interval between the main gaze line 14 and the vertical reference line Y is referred to as inward alignment.

  In the following description, the spectacle lens 10R for the right eye is mainly described as the spectacle lens. However, the spectacle lens, the spectacle lens, or the lens may be the spectacle lens 10L for the left eye. The eyeglass lens 10L is basically symmetrical to the right eyeglass lens 10R except for the difference in spectacle specifications between the left and right eyes. In the following description, the right-eye and left-eye spectacle lenses 10R and 10L are commonly referred to as spectacle lenses (or lenses) 10.

Example 1
3 shows changes in the surface refractive power OP along the main gaze line 14 of the object-side surface (outer surface) 19A of the progressive-power lens 10 of Example 1, and the main gaze line of the eyeball-side surface (inner surface) 19B. 14 schematically shows a change in the surface refractive power IP along 14 and a change in the visual power (average power) AP obtained by the surface refractive power of the outer surface 19A and the inner surface 19B.

In this specification, the surface refractive power and power are shown in units of diopter (D), and the surface refractive power IP of the inner surface 19B is shown as an absolute value. The visual power AP along the main gazing line 14, the surface refractive power OP of the outer surface 19A, and the surface refractive power IP of the inner surface 19B are approximately obtained by the following equations.
AP = OP-IP (8)

  The progressive-power lens 10 of Example 1 is designed with a progressive zone length of 24 mm, a prescription power (distance power, Sph) of 0.00 (D), and an addition power (Add) of 2.00 (D). is there. The lens 10 has a diameter of 65 mm and does not include astigmatism power.

  The outer surface 19A has a surface refractive power OP of 4.00 (D) for the distance portion 11 and a progressive zone length starting from 10 mm above the fitting point FP and ending at the fitting point FP. The minute ΔOP is 0.75 (D). That is, the outer surface 19A includes the first progressive surface 18A in which the surface refractive power OP changes, the start coordinate P1 of the first progressive surface 18A is the boundary PF between the distance portion 11 and the intermediate portion 13, and the end coordinate P2 is the fitting point FP, and the power change DOP due to the surface refractive power OP is 0.075 (D / mm).

  On the other hand, the inner surface 19B has a surface refractive power IP of 4.00 (D) of the distance portion 11 and a progressive zone length starting from 4 mm below the fitting point FP (smaller coordinate, minus side). It ends below 14 mm, and the change ΔIP of the surface refractive power IP is −1.25 (D). That is, the inner surface 19B includes the second progressive surface 18B in which the surface refractive power IP changes, the start coordinate P3 of the second progressive surface 18B is 4 mm below the fitting point FP, and the end coordinate P4 is the intermediate portion 13. And the near portion 12 is a boundary PN, and the power change DIP (absolute value) due to the surface refractive power IP is 0.089 (D / mm).

  Accordingly, the coordinate P1 of the first progressive surface 18A is larger than the coordinate P2, the coordinate P3 of the second progressive surface 18B is larger than the coordinate P4, and the coordinate P2 is larger than the coordinate P3. Therefore, the coordinates P1, P2, P3 and P4 satisfy the above conditions (2), (3) and (4).

  The visual power AP obtained by the outer surface 19A and the inner surface 19B of the progressive-power lens 10 includes a distance portion 11 having a visual power AP of 0.00 (D) and a near portion having a visual power AP of 2.00 (D). 12 and an intermediate portion 13 in which the visual power AP changes between the distance portion 11 and the near portion 12. Further, the intermediate portion 13 is connected to the distance portion 11 and is connected to the first region 131 having the first visual power gradient D1 and the near portion 12 and is provided with the second visual power gradient D2. Region 132 and a third region 133 located between the first region 131 and the second region 132, and a third region 133 having a third visual power gradient D3.

  The first visual power gradient D1 of the first region 131 is given by the first progressive surface 18A, and the approximate value of the first visual power gradient D1 is 0.075 (D / mm). The second visual power gradient D2 of the second region 132 is given by the second progressive surface 18B, and the approximate value of the first visual power gradient D2 is 0.089 (D / mm). The third visual power gradient D3 of the third region 133 is given by the surface after the first progressive surface 18A of the outer surface 19A ends and the surface of the inner surface 19B before the second progressive surface 18B starts. The approximate value of the third visual power gradient D3 is 0.00 (D / mm). Accordingly, the third visual power gradient D3 is smaller than the minimum value of the first visual power gradient D1 and the second visual power gradient D2, and the first visual power gradient D1, the second visual power gradient D2, and the third visual power gradient D2. The visual power gradient D3 satisfies the above condition (1).

  4A shows the astigmatism distribution on the outer surface 19A, FIG. 4B shows the astigmatism distribution on the inner surface 19B, and FIG. 4C shows the astigmatism distribution when viewed. 5A shows an average frequency distribution of the outer surface 19A, FIG. 5B shows an average frequency distribution of the inner surface 19B, and FIG. 5C shows an average frequency distribution at the time of visual observation. The vertical and horizontal straight lines in the figure indicate the reference lines (vertical reference line y and horizontal reference line x) that pass through the geometric center of the circular lens, and the frame is put into the spectacle frame with the geometric center that is the intersection as the fitting point. The shape image is also shown. The same applies to the following drawings.

  As a result of calculating a power gradient of the average power (third visual power gradient D3) of the third region 133 between the fitting point FP and 4 mm below the main gaze line 14, the third visual power gradient D3 is 0. 0.02 (D / mm), which was found to be smaller than the first visual power gradient D1 and the second visual power gradient D2. Thus, in the progressive-power lens 10, in the intermediate portion 13, the third region 133 where the first progressive surface 18A of the outer surface 19A and the second progressive surface 18B of the inner surface 19B do not overlap is formed. The power gradient D3 is smaller than the power gradients D1 and D2 of the other regions 131 and 132 of the intermediate portion 13. Therefore, it is possible to provide the progressive addition lens 10 having the region 133 with a small power gradient in the intermediate portion 13.

  FIG. 6A schematically shows the distance portion 11, the near portion 12, and the intermediate portion 13 of the progressive addition lens 10 x provided with the intermediate portion 13 having a uniform or continuous power gradient. FIG. 6B schematically shows the distance portion 11, the near portion 12, and the intermediate portion 13 of the progressive addition lens 10 having the intermediate portion 13 having a discontinuous power gradient.

  As shown in FIG. 6A, the progressive refraction in which the visual power (average power) AP changes continuously or at a uniform gradient in the intermediate portion 13 between the progressive start point PF and the progressive end point PN. In the power lens 10x, when the lens is used at a frequently used intermediate distance, for example, a distance to a display of a personal computer (PC) or a large TV, the frequency is continuously or continuously changed. (Intermediate part) 13 was used. Therefore, the magnification of the image often changes or the image is swayed, and it is difficult to obtain a comfortable visual field at an intermediate distance.

  In the progressive-power lens 10 of the present case, as shown in FIG. 6B, the change in the frequency is smaller in the intermediate portion 13 between the progressive start point PF and the progressive end point PN than in the other intermediate portions 13. A third region 133 having substantially no frequency change is provided. Therefore, by using the third region 133 when an image is obtained at an intermediate distance that is frequently used, a change in image magnification and distortion can be reduced. Therefore, it is possible to provide a progressive power lens 10 having a comfortable visual field at an intermediate distance and suitable for a user who frequently uses the intermediate distance. In the third region 133 with little or no frequency change, the main gazing line 14 is also set parallel to the vertical reference line Y so that the amount of inset is not changed.

  Further, in the progressive addition lens 10 of the first embodiment, the progressive portions (the first progressive surface 18A and the second progressive surface 18B) are provided separately on both the outer surface 19A and the inner surface 19B. Therefore, the lens can be manufactured while maintaining the optical performance of the intermediate visual field region. Further, by dispersing the influence of smoothing of the intermediate portion (progressive portion) 13 on both surfaces 19A and 19B, the influence on the intermediate visual field region can be reduced. Furthermore, since the required addition can be given to each of the outer surface 19A and the inner surface 19B, the more stable progressive addition lens 10 that controls the addition power for the intermediate distance required for the intermediate visual field region on one side can be provided. Can be manufactured.

  In this way, by carrying out a double-sided design in which the first progressive surface 18A is provided on the outer surface 19A and the second progressive surface 18B is provided on the inner surface 19B, the intermediate magnification is made larger in object magnification than the inner surface progressive design. A refractive lens can be provided. By increasing the object magnification, it is possible to make the intermediate and near-distance objects appear larger and make it easier to see the intermediate and short-distance objects.

  Further, the position of the progressive portion (second progressive surface) 18B on the inner surface 19B is moved up and down to easily control the amount of deviation from the progressive portion (first progressive surface) 18A of the outer surface 19A, and the intermediate visual field region It is possible to provide a progressive power lens 10 that can be easily designed in accordance with the size of the wearer.

That is, the magnification M of the progressive power lens is approximately expressed by the following equation.
M = Ms × Mp (9)
Here, Ms is called a shape factor, and Mp is called a power factor. The refractive index of the lens substrate is n, the base curve (surface refractive power) of the object side surface of the lens is D (diopter), the distance from the apex (inner apex) of the lens eyeball side surface to the eyeball is L, the inner side When the refractive power at the apex (inner apex refractive power) is P (frequency S) and the thickness of the lens center is t, Mp and Ms are expressed as follows.
Ms = 1 / (1-D × t / n) (10)
Mp = 1 / (1-L × P) (11)

  In calculating the expressions (10) and (11), diopter (D) is used for the base curve D and the inner vertex power P, and meters (m) are used for the thickness t and the distance L.

Therefore, Formula (9) becomes as follows.
M = {1 / (1-D × t / n)} × {1 / (1-L × P)} (12)
As can be seen from the equation (12), as the refractive power P increases, the magnification M also increases, and the intermediate portion 13 and the near portion 12 have a larger image magnification M than the distance portion 11. Accordingly, by performing a double-sided design in which the first progressive surface 18A is provided on the outer surface 19A and the second progressive surface 18B is provided on the inner surface 19B, the change in the object magnification M of the intermediate visual field region, particularly the third region 133, is achieved. It is possible to provide a progressive-power lens that is smaller than the inner surface progressive design.

(Example 2)
FIG. 7 shows changes in the surface refractive power OP along the main gaze line 14 of the object side surface (outer surface) 19A of the progressive-power lens 10 of Example 2, and the main gaze line of the eyeball side surface (inner surface) 19B. 14 schematically shows a change in the surface refractive power IP along 14 and a change in the visual power (average power) AP obtained by the surface refractive power of the outer surface 19A and the inner surface 19B.

  The progressive-power lens 10 of Example 2 is designed on the condition that the progressive zone length is 24 mm, the prescription power (distance power, Sph) is 0.00 (D), and the addition power (Add) is 2.00 (D). It is a thing. The lens 10 has a diameter of 65 mm and does not include astigmatism power.

  The inner surface 19B of the progressive-power lens of Example 2 has a surface refractive power IP of 4.00 (D) for the distance portion 11, and the progressive zone length starts from 10 mm above the fitting point FP and ends at the fitting point FP. The change ΔIP in the surface refractive power IP is −0.75 (D). That is, the inner surface 19B includes the second progressive surface 18B in which the surface refractive power IP changes, the start coordinate P3 of the second progressive surface 18B is the boundary PF between the distance portion 11 and the intermediate portion 13, and the end coordinate. P4 is a fitting point FP, and the power change DIP (absolute value) due to the surface refractive power IP is 0.075 (D / mm).

  On the other hand, the outer surface 19A has a surface refractive power OP of 4.00 (D) of the distance portion 11 and a progressive zone length starting from 4 mm below the fitting point FP and ending at 14 mm below the fitting point FP. The change ΔOP of is 1.25 (D). That is, the outer surface 19A includes the first progressive surface 18A in which the surface refractive power OP changes, the start coordinate P1 of the first progressive surface 18A is 4 mm below the fitting point FP, and the end coordinate P2 is the intermediate portion 13. And the near portion 12, and the power change DOP due to the surface refractive power OP is 0.089 (D / mm).

  Therefore, the coordinate P1 of the first progressive surface 18A is larger than the coordinate P2, the coordinate P3 of the second progressive surface 18B is larger than the coordinate P4, and the coordinate P4 is larger than the coordinate P1. Therefore, the coordinates P1, P2, P3 and P4 satisfy the above conditions (2), (3) and (5).

  The visual power AP obtained by the outer surface 19A and the inner surface 19B of the progressive-power lens 10 is approximately the same as the visual power AP of the progressive-power lens 10 of Example 1, as shown in FIG. Accordingly, the third visual power gradient D3 is smaller than the minimum value of the first visual power gradient D1 and the second visual power gradient D2, and the first visual power gradient D1, the second visual power gradient D2, and the third visual power gradient D2. The visual power gradient D3 satisfies the above condition (1).

  Similarly to the progressive-power lens 10 of Example 1, the progressive-power lens 10 of Example 2 also has an outer surface (object side surface) 19A and an inner surface (eyeball side surface) 19B along the main line of sight 14. It includes a progressive surface whose surface refractive power varies in different ranges, that is, a first progressive surface 18A and a second progressive surface 18B. Further, the outer surface (object side surface) 19A and the inner surface (eyeball side surface) 19B are progressively changed in surface refractive power so as to give the same visual power gradient to different positions along the main gazing line 14. A plane, ie, a first progressive surface 18A and a second progressive surface 18B are included. Then, the first area 131, the second area 132, and the third area 133 of the intermediate portion 13 are formed by the progressive surfaces 18A and 18B that do not overlap with each other, and the third area 133 with a small visual power gradient is intermediate. The progressive power lens 10 included in the portion 13 can be provided.

(Example 3)
FIG. 8 shows changes in the surface refractive power OP along the main gaze line 14 of the object-side surface (outer surface) 19A of the progressive-power lens 10 of Example 3, and the main gaze line of the eyeball-side surface (inner surface) 19B. 14 schematically shows a change in the surface refractive power IP along 14 and a change in the visual power (average power) AP obtained by the surface refractive power of the outer surface 19A and the inner surface 19B.

  The progressive-power lens 10 of Example 3 is designed under the conditions that the progressive zone length is 24 mm, the prescription power (distance power, Sph) is 0.00 (D), and the addition power (Add) is 2.00 (D). It is a thing. The lens 10 has a diameter of 65 mm and does not include astigmatism power.

  The inner surface 19B of the progressive-power lens of Example 3 has a surface refractive power IP of 4.00 (D) of the distance portion 11 and a progressive zone length starting from 10 mm above the fitting point FP and 14 mm below the fitting point FP. The change ΔIP of the surface power IP is −2.40 (D). That is, the inner surface 19B includes the second progressive surface 18B in which the surface refractive power IP changes, the start coordinate P3 of the second progressive surface 18B is the boundary PF between the distance portion 11 and the intermediate portion 13, and the end coordinate. P4 is a boundary PN between the near portion 12 and the intermediate portion 13, and the power change DIP (absolute value) due to the surface refractive power IP is 0.100 (D / mm).

  On the other hand, on the outer surface 19A, the distance power 11 of the distance portion 11 is 4.00 (D), the progressive zone length starts from the fitting point FP, ends at 4 mm below the fitting point FP, and the amount of change in the surface refractive power OP. ΔOP is −0.4 (D). That is, the outer surface 19A includes a first progressive surface (reverse progressive surface) 18A in which the surface refractive power OP changes in a reverse tendency, the start coordinate P1 of the first progressive surface 18A is the fitting point FP, and the end coordinate P2 Is 4 mm below the fitting point FP, and the power change DOP (absolute value) due to the surface refractive power OP is 0.100 (D / mm).

  Therefore, the coordinate P1 of the first progressive surface 18A is larger than the coordinate P2, the coordinate P3 of the second progressive surface 18B is larger than the coordinate P4, and the start coordinate P1 of the first progressive surface 18A is the second coordinate. It is smaller than the start coordinate P3 of the progressive surface 18B, and the end coordinate P2 of the first progressive surface 18A is larger than the end coordinate P4 of the second progressive surface 18B. Therefore, the coordinates P1, P2, P3 and P4 satisfy the above conditions (2), (3) and (7).

  The visual power AP obtained by the outer surface 19A and the inner surface 19B of the progressive-power lens 10 is substantially the same as the visual power AP of the progressive-power lens 10 of Example 1 as shown in FIG. The visual power of is approximately constant at 1.00 (D). Accordingly, the third visual power gradient D3 is smaller than the minimum value of the first visual power gradient D1 and the second visual power gradient D2, and the first visual power gradient D1, the second visual power gradient D2, and the third visual power gradient D2. The visual power gradient D3 satisfies the above condition (1).

  Similarly to the progressive-power lens 10 of Example 1, the progressive-power lens 10 of Example 3 also has an outer surface (object side surface) 19A and an inner surface (eyeball side surface) 19B along the main line of sight 14. It includes a progressive surface whose surface refractive power varies in different ranges, that is, a first progressive surface 18A and a second progressive surface 18B. Further, the outer surface (object-side surface) 19A and the inner surface (eyeball-side surface) 19B further have surface refractive power so as to give a reverse power gradient to the overlapping position along the main line of sight 14. It includes a progressive surface that changes, that is, a first progressive surface 18A and a second progressive surface 18B. Then, the first surface 131, the second region 132, and the third region 133 of the intermediate portion 13 are formed by the progressive surfaces 18A and 18B that are partially overlapped, and the third region 133 with a small visual power gradient is formed. The progressive addition lens 10 included in the intermediate portion 13 can be provided.

  Further, in the progressive addition lens 10 of the third embodiment, the reverse progressive surface 18A is formed on the outer surface 19A, and the surface refractive power (base curve) OP is smaller in the near portion 12 than in the distance portion 11. Yes. Therefore, as shown in the equation (12), when the refractive power P is increased, the magnification M is also increased, and the intermediate portion 13 and the near portion 12 have an image magnification M greater than that of the distance portion 11. However, since the surface refractive power OP of the outer surface 19A is reduced, the magnification difference between the images of the distance portion 11, the intermediate portion 13, and the near portion 12 can be reduced.

Example 4
FIG. 9 shows changes in the surface refractive power OP along the main gaze line 14 of the object side surface (outer surface) 19A of the progressive-power lens 10 of Example 4, and the main gaze line of the eyeball side surface (inner surface) 19B. 14 schematically shows a change in the surface refractive power IP along 14 and a change in the visual power (average power) AP obtained by the surface refractive power of the outer surface 19A and the inner surface 19B.

  The progressive-power lens 10 of Example 4 is designed on the condition that the progressive zone length is 24 mm, the prescription power (distance power, Sph) is 0.00 (D), and the addition power (Add) is 2.00 (D). It is a thing. The lens 10 has a diameter of 65 mm and does not include astigmatism power.

  As for the outer surface 19A of the progressive-power lens of Example 4, the surface refractive power IP of the distance portion 11 is 4.00 (D), the progressive zone length starts from 10 mm above the fitting point FP, and 14 mm below the fitting point FP. The change ΔOP of the surface power OP is 2.40 (D). That is, the outer surface 19A includes the first progressive surface 18A in which the surface refractive power OP changes, the start coordinate P1 of the first progressive surface 18A is the boundary PF between the distance portion 11 and the intermediate portion 13, and the end coordinate P2 is the boundary PN between the near portion 12 and the intermediate portion 13, and the power change DOP due to the surface refractive power OP is 0.100 (D / mm).

  On the other hand, the inner surface 19B has a surface refractive power IP of 4.00 (D) for the distance portion 11 and a progressive zone length starting from the fitting point FP and ending at 4 mm below the fitting point FP. ΔIP is 0.4 (D). That is, the inner surface 19B includes a second progressive surface (reverse progressive surface) 18B in which the surface refractive power IP changes in a reverse tendency, the start coordinate P3 of the second progressive surface 18B is the fitting point FP, and the end coordinate P4. Is 4 mm below the fitting point FP, and the power change DIP due to the surface refractive power IP is 0.100 (D / mm).

  Therefore, the coordinate P1 of the first progressive surface 18A is larger than the coordinate P2, the coordinate P3 of the second progressive surface 18B is larger than the coordinate P4, and the start coordinate P1 of the first progressive surface 18A is the second coordinate. It is larger than the start coordinate P3 of the progressive surface 18B, and the end coordinate P2 of the first progressive surface 18A is smaller than the end coordinate P4 of the second progressive surface 18B. Therefore, the coordinates P1, P2, P3 and P4 satisfy the above conditions (2), (3) and (8).

  The visual power AP obtained by the outer surface 19A and the inner surface 19B of the progressive-power lens 10 is substantially the same as the visual power AP of the progressive-power lens 10 of Example 1, as shown in FIG. The visual power of is approximately constant at 1.00 (D). Accordingly, the third visual power gradient D3 is smaller than the minimum value of the first visual power gradient D1 and the second visual power gradient D2, and the first visual power gradient D1, the second visual power gradient D2, and the third visual power gradient D2. The visual power gradient D3 satisfies the above condition (1).

(Example 5)
FIG. 10 shows changes in the surface refractive power OP along the main gaze line 14 of the object-side surface (outer surface) 19A of the progressive-power lens 10 of Example 5, and the main gaze line of the eyeball-side surface (inner surface) 19B. 14 schematically shows a change in the surface refractive power IP along 14 and a change in the visual power (average power) AP obtained by the surface refractive power of the outer surface 19A and the inner surface 19B.

  The progressive-power lens 10 of Example 5 is designed on the condition that the progressive zone length is 24 mm, the prescription power (distance power, Sph) is 0.00 (D), and the addition power (Add) is 2.00 (D). It is a thing. The lens 10 has a diameter of 65 mm and does not include astigmatism power.

  The outer surface 19A of the progressive-power lens of Example 5 is a spherical surface having a surface refractive power OP of 4.00 (D). On the other hand, the inner surface 19B has a progressive surface 17A having a surface refractive power IP of 4.00 (D) of the distance portion 11 and a progressive zone length starting from 10 mm above the fitting point FP and ending at the fitting point FP, and the fitting point FP. And a progressive surface 17B starting from 4 mm below and ending 14 mm below the fitting point FP. The change ΔIP of the surface refractive power IP of the progressive surface 17A is −0.75 (D), and the change ΔIP of the surface refractive power IP of the progressive surface 17B is −1.25 (D). The surface refractive power IP between the progressive surface 17B does not change and is constant at 3.25 (D).

  Therefore, the visual power AP obtained by the outer surface 19A and the inner surface 19B of the progressive-power lens 10 is substantially the same as the visual power AP of the progressive-power lens 10 of Example 1, as shown in FIG. The visual power gradient D3 is smaller than the minimum value of the first visual power gradient D1 and the second visual power gradient D2, and the first visual power gradient D1, the second visual power gradient D2, and the third visual power gradient D3. Satisfies the above condition (1).

  FIG. 11 shows a process of designing and manufacturing the progressive addition lens 10. In step 101, an outer surface (object side surface) 19A and an inner surface (eyeball side surface) 19B are designed based on spectacles specifications. At this time, the intermediate portion 13 includes the first region 131, the second region 132, and the third region 133, the first visual power gradient G1 of the first region 131, and the second region 132 of the second region 132. The outer surface 19A and the inner surface 19B are designed so that the visual power gradient D2 and the third visual power gradient D3 of the third region 133 satisfy the above condition (1).

  Typically, in step 102 of designing the outer surface 19A, the intermediate portion 13 is designed to include the first progressive surface 18A, and in step 103 of designing the inner surface 19B, the intermediate portion defines the second progressive surface 18B. Design to include. When the coordinates P1 to P4 along the main gazing line 14 of the first progressive surface 18A and the second progressive surface 18B satisfy the above conditions (2) and (3), in steps 102 and 103, the coordinates P1 The outer surface 19A including the first progressive surface 18A and the inner surface 19B including the second progressive surface 18B are designed so that .about.P4 satisfies any of the above conditions (4) to (7).

  Next, in step 104, the progressive-power lens 10 for spectacles having the inner and outer surfaces designed as described above is manufactured.

  The progressive-power lens 10 described above includes a third region 133 in the intermediate portion 13 whose visual power change is smaller than other regions of the intermediate portion 13. Currently, more work is performed at intermediate distances. For example, considering that the distance to the PC display is 60 cm to 80 cm and the viewing distance of medium-sized and large-sized TVs is 1.0 m to 2.0 m, the frequency of use of the intermediate portion 13 of the progressive addition lens 10 is increasing. . Therefore, the third region 133 having a small (small) visual power change is set as the intermediate visual field region in the intermediate portion 13, and the progressive addition power in which the addition power of the intermediate visual field region is determined corresponding to the frequently used intermediate distance. By designing and manufacturing the lens 10, it is possible to design and provide a progressive power lens 10 suitable for users who frequently use intermediate distances.

  In particular, by employing a double-sided design in which progressive surfaces 18A and 18B are provided on the outer surface 19A and the inner surface 19B as described above, the addition power of the intermediate visual field region can be easily set. Further, by providing a progressive zone (progressive surface) on one surface above the fitting point FP, the addition power of the intermediate visual field region can be set more flexibly.

  The design of the outer surface 19A and the inner surface 19B exemplified above is merely an example, and curved surfaces having various shapes may be adopted based on spectacles specifications within the scope described in the claims.

DESCRIPTION OF SYMBOLS 1 Glasses, 10, 10L, 10R Glasses lens 11 Distance part, 12 Near part, 13 Middle part (progressive part)
19A Object side surface, 19B Eyeball side surface 20 Frame

Claims (12)

A progressive-power lens for spectacles having a distance portion and a near portion having different visual powers, and an intermediate portion located between the distance portion and the near portion,
The intermediate portion is connected to the distance portion, the first region having a first visual power gradient D1,
A second region connected to the near portion and having a second visual power gradient D2,
A third region located between the first region and the second region, the third region having a third visual power gradient D3, and the first visual power gradient D1 The progressive power lens, wherein the second visual power gradient D2 and the third visual power gradient D3 satisfy the following conditions.
| D3 | <MIN (| D1 |, | D2 |)
However, MIN is a function indicating a minimum value.   The progressive-power lens according to claim 1, wherein the third region includes a fitting point. 3. The intermediate part according to claim 1, wherein the object side surface of the intermediate part includes a first progressive surface whose surface refractive power changes between the coordinates P1 and the coordinates P2 along the main gazing line. The side surface includes a second progressive surface whose surface refractive power changes between coordinates P3 and P4 along the main gazing line. The coordinates P1, P2, P3, and P4 are different from each other, and the following conditions are satisfied. Satisfactory, progressive addition lens.
P1> P2
P3> P4 In Claim 3, said 1st progressive surface and said 2nd progressive surface are the surfaces which give the visual power power gradient of the same tendency, The said coordinates P1, P2, P3, and P4 are further in any of the following conditions A progressive-power lens that meets these requirements.
P2> P3
P1 <P4 In Claim 3, said 1st progressive surface and said 2nd progressive surface are surfaces which give a visual power gradient of reverse tendency, and said coordinates P1, P2, P3, and P4 are any of the following conditions: A progressive-power lens that meets these requirements.
P1> P3 and P2 <P4
P1 <P3 and P2> P4   3. The progressive-power lens according to claim 1, wherein the object-side surface and the eyeball-side surface of the intermediate portion include progressive surfaces whose surface refractive power changes in different ranges along the main line of sight.   The progressive surface according to claim 6, wherein the object-side surface and the eyeball-side surface include a progressive surface whose surface refractive power changes so as to give a visual power gradient having the same tendency to different positions along the main line of sight. Refracting lens. A progressive-power lens according to any one of claims 1 to 7,
Eyeglasses having an eyeglass frame to which the progressive addition lens is attached. A design method of a progressive-power lens for spectacles having a distance portion and a near portion having different visual powers, and an intermediate portion located between the distance portion and the near portion,
A first region connected to the distance portion and provided with a first visual power gradient G1, and a second region connected to the near portion and provided with a second visual power gradient D2. A third region located between the first region and the second region, the third region having a third visual power gradient D3,
A method for designing a progressive power lens, wherein the first visual power gradient D1, the second visual power gradient D2, and the third visual power gradient D3 satisfy the following conditions.
| D3 | <MIN (| D1 |, | D2 |)
However, MIN is a function indicating a minimum value. A design method of a progressive-power lens for spectacles having a distance portion and a near portion having different visual powers, and an intermediate portion located between the distance portion and the near portion,
Designing an object-side surface; designing the object-side surface; designing an eyeball-side surface before or after;
Designing the object-side surface is a first progressive surface included in the intermediate portion, and the surface refractive power changes between the coordinate P1 along the main line of sight and the coordinate P2 smaller than the coordinate P1. Designing a first progressive surface to
Designing the eyeball-side surface is a second progressive surface included in the intermediate portion, and is between the coordinates P3 along the main gaze line and coordinates P4 smaller than the coordinates P3. Including designing a second progressive surface whose surface refractive power changes so as to provide a visual power gradient having the same tendency as the progressive surface, and the coordinates P1, P2, P3, and P4 satisfy any of the following conditions: , Design method of progressive power lens.
P2> P3
P1 <P4 A design method of a progressive-power lens for spectacles having a distance portion and a near portion having different visual powers, and an intermediate portion located between the distance portion and the near portion,
Designing an object-side surface; designing the object-side surface; designing an eyeball-side surface before or after;
Designing the object-side surface is a first progressive surface included in the intermediate portion, and the surface refractive power changes between the coordinate P1 along the main line of sight and the coordinate P2 smaller than the coordinate P1. Designing a first progressive surface to
Designing the eyeball-side surface is a second progressive surface included in the intermediate portion, and is between the coordinates P3 along the main gaze line and coordinates P4 smaller than the coordinates P3. Including designing a second progressive surface whose surface refractive power changes so as to provide a visual power gradient having a reverse tendency to the progressive surface, and the coordinates P1, P2, P3, and P4 satisfy any of the following conditions: , Design method of progressive power lens.
P1> P3 and P2 <P4
P1 <P3 and P2> P4   A method for manufacturing a progressive-power lens, comprising manufacturing a progressive-power lens designed by the design method according to claim 9.

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