This application claims the benefit of Taiwan application Serial No. 107130703, filed Aug. 31, 2018, the subject matter of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The invention relates in general to an optical lens, and more particularly to an optical lens with low distortion, large aperture size and field of view, and compact volume.

BACKGROUND

In recent years, due to the rise of random photography activities in motion, the demand for a light and short optical lens has increased substantially, and the trend in a compact image capturing device with high-quality images has grown up. Such a type of device is mainly used for outdoor activities for real-time photography. The lens for this type of device requires a short total length and a ultra wide viewing angle.

The image capturing device generally used in a normal environment has low elasticity to modulate the camera parameters with the environment. For example, the problem of image quality of the image capturing device cannot be overcome since the change of refractive index of the environmental medium will have the viewing angle become smaller and the resolution be lowered. Thus, it is difficult for the image capturing device to achieve stable image quality and ultra wide viewing angle. Therefore, it is desired to provide a novel optical lens and an electronic device, which can maintain a certain resolution with environmental factors under the premise that the viewing angle is increased or substantially unchanged.

SUMMARY

In view of this, the present invention provides an optical lens. The optical lens, in order from an object side to an image-forming side, includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens. The first lens has negative refractive power, the second lens has negative refractive power, the third lens has positive refractive power, the fourth lens has positive refractive power, the fifth lens has negative refractive power, the sixth lens has positive refractive power, the seventh lens has positive refractive power, and the eighth lens has negative refractive power.

The present invention further provides an optical lens. The optical lens, in order from an object side to an image-forming side, includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens. The first lens has negative refractive power, and includes an object-side surface and an image-side surface. R1is a curvature radius of the object-side surface, R2is a curvature radius of the image-side surface, and |R1/R2|≥1. The second lens has refractive power, the third lens has positive refractive power, the fourth lens has positive refractive power, the fifth lens has negative refractive power, the sixth lens has positive refractive power, the seventh lens has positive refractive power, and the eighth lens has negative refractive power.

The present invention also provides an optical lens. The optical lens, in order from an object side to an image-forming side, includes: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, a seventh lens and an eighth lens. The first lens has negative refractive power, the second lens has refractive power, the third lens has positive refractive power, the fourth lens has positive refractive power, the fifth lens has negative refractive power, the sixth lens has positive refractive power, and the seventh lens has positive refractive power. In addition, the eighth lens includes an image-side surface with a vertex point, r is an effective radius of the image-side surface, the image-side surface intersects with the optical axis at an intersection point, H is a distance between the vertex point and the optical axis, the vertex point projects on the optical axis at a projection location, d is a distance between the projection location and the intersection point, and |r/d|≤30 and/or |r/H|≤2.

As stated above, the optical lens provided by the present invention features low distortion, large aperture size and field of view, compact volume and low cost.

