Motorcycle goggles are a type of filter that can change the intensity and spectrum of transmitted light. The most effective and common way to avoid eye damage from radiation is to wear protective glasses. These glasses can absorb light of some wavelengths and allow light of other wavelengths to pass through, so they all show a certain color, and the color presented is the color of transmitted light. One is the absorption type and the other is the reflection type. The former is used most often. Goggles are glasses that can change the intensity and spectrum of transmitted light to prevent radiation from causing damage to the eyes. These glasses are divided into two categories, one is the absorption type, and the other is the reflection type. The former is used the most. These glasses can absorb light of some wavelengths and allow light of other wavelengths to pass through, so they all show a certain color, and the color presented is the color of transmitted light.
Materials for manufacturing motorcycle goggles: When manufacturing this lens, a part of metal oxides such as iron, diamond, chromium, strontium, nickel, manganese and some rare earth metal oxides such as and neodymium are added to the general optical glass formula . These metal oxides enable glass to selectively absorb electromagnetic waves in a certain band of light. For example, oxides of cerium and iron can absorb ultraviolet rays in large quantities. The use of such glass lenses can reduce the amount of light passing through the lens at certain wavelengths, reducing or preventing eye damage. Different color protective lenses can absorb different colors of light. These glasses are divided into two categories, one is the absorption type, the other is the reflection type, the former is used the most.
Lens hair is generally round, the specifications are expressed by its diameter, the unit is mm, there are φ48, φ50, φ52, φ56, φ60, φ65, φ70 and so on. The most commonly used are φ56, φ60, and φ65. Due to the popularity of large frames, the use of large size lenses such as φ70 has increased.
Motorcycle goggles lens size:
The size and shape of the spectacle lens that conforms to the shape of the frame after the hair piece processing is naturally determined by the curve of the inner edge of the frame. The lens should indicate the horizontal direction and the nasal side, otherwise the asymmetrically shaped lens will become a completely different shape after rotation. The size of the lens is expressed by both the length of the reference line and the height of the reference line (reference line method), that is, AA '× B'B in mm (for example, 46 × 40); or the horizontal and vertical dimensions of the circumscribed rectangle ( Box method). The lens shape is represented by a shape difference. The so-called sheet shape difference is the difference between the length of the reference line and the height of the reference line (baseline method), or the difference between the horizontal and vertical dimensions of the circumscribed rectangle (box method). What is not specified is the baseline method. For example, a 46 × 40 lens has a sheet shape difference of 6 (ie, 46-40). Different lens shapes of some lens series are represented by the shape difference. The shape difference is 3 or 4, which is a high shape; the shape difference is 10, which is a short shape. Early lenses were symmetrical-round or oval. The circular lens has a difference in shape of 0, a short ellipse of 4, and a long ellipse of 9. The semicircle is connected under the semiellipse to form a "Pantoscopic Round Oval" (PRO). There are a variety of sheet differences. The larger sheet difference is called the "wide field of vision" shape. In addition, there are "outline shapes", "squares", "borderless shapes" and "sport shapes" and so on. The change in lens shape is mainly caused by the continuous refurbishment of modern eyeglass frames. Frames with different baseline lengths (such as 40, 42, 44, 46) can have the same sheet shape difference 4 (such as 40 × 36, 42 × 38, 44 × 40, 46 × 42), but they are not the same as each other Proportion, so the sheet shape also varies.
Motorcycle goggles mirror cut:
In the box method, it is the difference from the horizontal size of the circumscribed rectangle. Therefore, LSWF should indicate whether it is a box method. Determine the LSWF, find the geometric center of the frame or the cut lens that conforms to the shape of the frame, which is the M point in the baseline method; measure the maximum distance from the center of the collection to the edge of the frame or lens; twice the distance is the minimum The diameter of the uncut lens; the measured length of the scene or the baseline of the lens; the difference between the minimum uncut lens diameter and the length of the baseline is LSWF. The maximum distance from the geometric center (M) of the lens to the edge of the lens is 29mm, so 58mm is the minimum diameter of the lens. If the reference line length (AA ') is 48 mm, the LSWF is 10 mm. LSWF, can choose the appropriate size of hair pieces for cutting, especially when the lens needs to be centered. If the manufacturer can mark the frame LSWF on each pair of frames, it will enable us to easily determine the minimum specifications of the hair pieces before cutting the lens that needs to be centered. Lens thickness can be measured with a thicknesscaliper. Place the lens between the claws J, and the pointer P will move a certain distance d on the arc facet, which indicates the thickness of the measured lens, and the scale can be accurate to 0.1mm. The similar triangle principle can be obtained: the movement distance d = lens Thickness × CP / CJ The caliper's long and short arms are usually designed as a 4: 1 ratio, that is, CP / CJ is 4, the lens thickness is d / 4mm, and the arc scale can be determined from this
Motorcycle goggles diopter:
Lens measurement table (spherical instrument): This table can measure the sag between K and L. The distance from K to L is 2y, the middle moving stylus and the surface pointer are connected by gears, and the surface scale is the diopter.
According to the approximate vertical formula of Chapter 6 of motorcycle goggles, the obtained diopter is: F = s × 2000 (n-1) / y2 where 2000 (n-1) / y2 is a constant for this table. If the distance between the two fixed styluses in this table is 20mm, and the refractive index of the measured lens is set to 1.523, then the constant is: 2000 (n-1) /y2=2000×0.523/102=10.46 then the formula (16 -1) is: F = 10.46 × s If the middle movable stylus is 1mm below the line of the fixed stylus during the measurement, the reading of the lens measuring meter will be F = 10.46 × 1 = + 10.46D; if s is 0.5mm higher, The scale reading will be + 5.23D. If the middle moving stylus grows below the two fixed stylus lines, the pointer will turn in the opposite direction and the reading will be negative. Some lens scales can measure ± 20.00D. Although the approximate sag formula has been able to explain the principle of the lens scale, in fact, the scale of the lens scale is still corrected by the exact sag formula. When the middle moving stylus is compressed by 1mm, the corrected scale is actually + 10.37D instead of + 10.46D. When taking a ball mirror reading, place the measuring probe stylus vertically on the concave surface of the lens being tested. When all three stylus contacts the mirror surface, read the reading indicated by the surface pointer, and then measure the convex surface to get another reading. The algebraic sum is the reading of the lens, and the-or + mark where the reading with a large absolute value indicates that the lens is a negative or positive lens. When measuring a lenticular lens, turn the lens clockwise, and the reading indicated by the pointer on one side (usually on the convex side) changes, which is the astigmatism side. The difference between the maximum and minimum scales on this surface is the astigmatism reading, and the meridian direction of the minimum scale is the axis of the cylinder. The error measured by the measuring table is that the lens below 6.00D is within 0.1D, and the lens above 6.00D is within 0.25D. However, when the stylus is worn or the stylus is not perpendicular to the mirror surface, there may be a large error. Attention should be paid to the correct measurement, and the zero position should be periodically corrected with a standard plane.