JP2728626B2 - Bifocal glasses - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to bifocal spectacles which allow both perspective and observable viewing at a fixed viewing angle.

[0002]

2. Description of the Related Art In general bifocal glasses, a far vision area is provided above a lens, and a near vision area is provided below the lens. And
When looking at the hand, the user lowers his / her gaze and uses the near area.

[0003]

However, when it is necessary to keep watching the hand for a long time using such bifocal glasses (when performing work such as reading or drafting), the gaze must be directed downward for a long time. The drawback is that your eyes are very tired because you have to keep them.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide bifocal glasses that allow the user to see both the perspective and the perspective at a fixed viewing angle.

Another object of the present invention is to facilitate the operation of switching the distance of the bifocal glasses.

[0006]

In order to achieve the above-mentioned object, the bifocal glasses according to the present invention, as described in claim 1, are provided with a distance area on one of the upper and lower sides and a distance area on the other side. In bifocal spectacles provided with a pair of left and right lenses provided on the rim of the frame, the lenses are formed so that the line-of-sight transmission directions of the distance region and the near region are opposite to each other, and the top and bottom of the lens are The lens is held on the rim so that it can be turned upside down so that the spectacle wearer naturally looks forward when the line of sight always passes either above or below the rim frame, and the front and back positions of the lens Regardless of this, the dimensions of the frame and the rim were set so that the line of sight transmits through the lens region having the correct line of sight transmission direction.

Further, as set forth in claim 2, when the lens is turned upside down, a front and back positioning means for positioning a fixed position of the lens is provided.

[0008]

According to the bifocal spectacles having the above structure, the upside-down direction of the lens is reversed by reversing the front and back of the lens, and it is provided on the other side with the far vision area provided on one side of the upper and lower sides of the lens. The position of the near area is switched. And, irrespective of the front and back positions of such a lens, the line of sight when the spectacle wearer naturally looks forward always passes through the lens area having the correct line of sight transmission direction.

For this reason, for example, when the distance area has the correct line-of-sight transmission direction above the lens, if the front and back of the lens are reversed, then the near area will have the correct line-of-sight transmission direction above the lens. In any case, the line of sight of the spectacle wearer naturally passes through the lens area having the correct line of sight transmission direction.

Therefore, when looking at the distance, the front and back of the lens are aligned so that the line of sight when looking forward naturally passes through the far vision area, and when looking at the hand, the front and back sides of the lens such that the visual line passes through the near vision area. If you match, you can always see the object with a constant natural gaze angle when looking at a distance or at hand.

In addition, the front and back positioning means quickly positions the inverted lens at the home position. Therefore, the front and back of the lens, that is, the operation of switching the distance is performed quickly.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of the bifocal glasses according to the present invention, and FIGS. 2A and 2B are front views of the bifocal glasses. FIGS. 3A and 3B are right side views of the bifocal glasses.

The bifocal glasses 1 include, for example, a metal frame 2. The frame 2 includes a pair of left and right rims 3, a bridge 4 connecting between the rims 3,
A pair of left and right temples 6 pivotally attached to the outside by hinges 5 and extending rearward, a nose pad 7 provided inside the left and right rims 3, an ear cover 8 provided at the rear end of the temple 6, and the like. Are configured.

The rim 3 holds, for example, a square lens 11. The lens 11 has a distance area A
And the near area B are provided above and below the boundary C. The far-sighted area A is an area for viewing farther than the hand, and a lens adapted to myopia, astigmatism, and the like is provided in this area. On the other hand, the near area B is provided with a lens that allows the user to see at hand even in the case of far vision.

As shown in FIG. 4, the lens 11 is formed such that the line-of-sight transmission directions X and Y of the distance area A and the near area B are opposite to each other. That is, for example, the distance area A functions as a convex lens for myopia or astigmatism when viewed in the line-of-sight transmission direction X, and the near area B is viewed in the line-of-sight transmission direction Y opposite to the line-of-sight transmission direction X. In order to function as a concave lens for hyperopia, a far vision area A and a near vision area B are formed as lenses having opposite sides.

The position of the boundary line C is linearly provided so that, for example, the area of the distance area A is larger than the area of the near area B, but the position of the boundary line C may be shifted. , By bending the boundary line C, etc.
The area ratio and the shape of the near region B can be changed.

The lens 11 is held on the frame 2 so that it can be turned upside down so that the lens 11 is turned upside down. FIG.
Fig. 6 is a detailed internal cross-section at a portion V in Fig. 2 (A).
FIG. 6 is a sectional view taken along line -V, and FIG. 6 is a sectional view taken along line VI-VI of FIG. As shown in FIGS. 2, 5, and 6, a frame portion 12 made of, for example, metal and having a U-shaped cross section is fixed to both sides of each lens 11. Pivot shafts 13 protruding from both sides are provided. On the other hand, the rim 3 holding the lens 11 is provided with a bearing portion 14 for rotatably supporting the pivot shaft 13.

Therefore, the lens 11 can be rotated inside the rim 3 about the pivot shaft 13 and can be turned upside down.
When the lens 11 is turned upside down, the upper and lower positions of the distance area A and the near area B are switched.

The frame 2 and the rim 3 are
Irrespective of the front and back positions, the line of sight when the wearer of the bifocal glasses 1 naturally looks forward is formed to pass through the lens area A or B having the correct line of sight transmission direction. That is, as shown in FIG. 3, the dimensions of the frame 2 and the rim 3 are set so that the line of sight Z when the wearer of the bifocal glasses 1 naturally looks forward always passes above the frame of the rim 3. ing. The dimensions of the frame 2 and the rim 3 may be set so that the line of sight Z always passes below the inside of the frame of the rim 3.

In the state shown in FIG. 3A, since the distance area A of the lens 11 is located above the frame of the rim 3, the line of sight Z of the spectacle wearer passes through the distance area A. Therefore, the bifocal glasses 1 function as glasses for myopia or astigmatism. In the state shown in FIG. 3B, the lens 11 is inverted and the near area B is on the upper side.
Through. Accordingly, the bifocal glasses 1 function as hyperopic glasses.

According to the bifocal glasses 1 configured as described above, the far vision area A is located on the upper side when looking far away.
By turning the front and back of the lens 11 so that the near area B is on the upper side when looking at the hand, it is possible to always see an object at a constant natural line-of-sight angle both when looking far away and when looking at the hand. For this reason, an unreasonable gaze angle is not forced, and eyestrain can be effectively prevented.

Incidentally, the bifocal glasses 1 include a lens 11.
A front and back positioning means 15 is provided for positioning the lens 11 at a fixed position when the front and back are reversed. As shown in FIG. 4, the front and back positioning means 15 has an inner peripheral cross-sectional shape of an upper side and a lower side of the rim 3 having, for example, a shallow C-shaped cross section, and the upper side and the lower side of the lens 11 are lightly fitted therein. It is constituted by doing.

Therefore, when the lens 11 is turned upside down, the upper and lower sides of the lens 11 are gently pushed to remove the lens 11 from the rim portion 3 and the lens 11 is turned around the pivot shaft 13 and then the upper and lower sides of the lens 11 are turned. Should be fitted into the rim 3 again.

In this manner, when the lens 11 is turned upside down, the lens 11 is quickly positioned at the home position, so that the front and back of the lens 11, that is, the operation of switching the perspective can be quickly performed, and the usability of the bifocal glasses 1 is improved. Will be very good.

The front / back positioning means 15 is not limited to the above-described structure.
Another configuration may be adopted in which resistance is given to the rotation of the lens 11 and natural rotation of the lens 11 is prevented.

In this embodiment, the lens 11 is formed in a square shape. However, as long as the lens 11 is vertically symmetrical with respect to the pivot shaft 13, the lens 11 is not limited to a square shape but may be formed in a circular shape or any other shape. It does not matter.

[0027]

As described above, the bifocal glasses according to the present invention have a pair of left and right lenses provided with a distance area on one upper and lower side and a near area on the other side on the rim of the frame. In the provided bifocal glasses, the lens is formed so that the line of sight transmission direction of the distance region and the near region is opposite, and the lens is held on the rim so that the lens can be turned upside down so that the lens is upside down. When the spectacle wearer naturally looks forward, the line of sight always passes either above or below the rim frame, and the line of sight has the correct line of sight transmission direction regardless of the front and back positions of the lens. The dimensions of the frame and rim are set so that the light is transmitted.

According to the bifocal spectacles having the above-described configuration, the upside down of the lens is reversed by inverting the front and back of the lens, and the farsighted area provided on one side of the upper and lower sides of the lens and the other side are provided on the other side. The position of the near area is switched.
And, irrespective of the front and back positions of such a lens, the line of sight when the spectacle wearer naturally looks forward always passes through the lens area having the correct line of sight transmission direction.

For this reason, for example, if the distance area has the correct line-of-sight transmission direction above the lens, the near area has the correct line-of-sight transmission direction above the lens by reversing the front and back of the lens. In any case, the line of sight of the spectacle wearer naturally passes through the lens area having the correct line of sight transmission direction.

Therefore, when looking at the distance, the front and back of the lens are aligned so that the line of sight when looking forward naturally passes through the far vision area, and when looking at the hand, the front and back sides of the lens such that the visual line passes through the near vision area. If you match, you can always see the object with a constant natural gaze angle when looking at a distance or at hand. Therefore, the eyestrain can be effectively prevented without forcing an excessive gaze angle.

Further, the bifocal glasses according to the present invention are provided with front and back positioning means for positioning the lens at a predetermined position when the lens is reversed, so that the inverted lens can be quickly positioned at the fixed position. Can be. For this reason, the front and back of the lens can be aligned, that is, the perspective switching operation can be quickly performed, and the usability of the bifocal glasses is greatly improved.

[Brief description of the drawings]

FIG. 1 is a plan view of bifocal glasses according to the present invention.

FIG. 2 (A) is a front view of the bifocal glasses when the distance area A of the lens is on the upper side, and FIG. 2 (B) is a front view of the bifocal glasses when the near area B of the lens is on the upper side. FIG.

FIG. 3 is a view showing one embodiment of the present invention, wherein (A) is a right side view of the bifocal glasses when the distance area A of the lens comes to the upper side,
(B) is a right side view of the bifocal glasses when the near area B of the lens comes to the upper side.

FIG. 4 is a longitudinal sectional view of the bifocal glasses along the line IV-IV in FIG. 2 (A).

FIG. 5 is a detailed internal cross section of a portion V in FIG.
Sectional drawing shown along the VV line of FIG.

FIG. 6 is a sectional view taken along the line VI-VI of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bifocal glasses 2 Frame 3 Rim 6 Temple 11 Lens 12 Frame 13 Pivot shaft 14 Bearing 15 Front and back positioning means A Distance area B Near area X Line of sight transmission direction of distance area Y Line of sight transmission of near area B Direction Z Gaze when the spectacle wearer naturally looks ahead

Claims (2)

(57) [Claims] 1. A pair of right and left lenses 11 provided on a rim 3 of a frame 2 with a pair of left and right lenses 11 provided with a distance region A on one upper side and a near region B on the other side.
Is formed such that the line of sight of the distance area A and the near area B are opposite to each other, and the lens 11 is held on the rim 3 so that the lens 11 can be turned upside down so that the lens 11 is turned upside down. The line of sight Z when the user naturally looks forward always passes either above or below the frame of the rim 3 and the lens
The frame 2 and the rim 3 are so arranged that the line of sight Z is transmitted through the lens area having the correct line of sight transmission direction irrespective of the front and back positions of 11.
The bifocal glasses 1 characterized in that the following dimensions are set. 2. The bifocal glasses according to claim 1, further comprising: front and back positioning means for positioning a fixed position of the lens when the lens is turned upside down.