WO2017200278A1 - Wide-angle lens system and vehicle camera provided with same - Google Patents

Abstract

The present invention relates to a wide-angle lens system and a vehicle camera provided with same, the wide-angle lens system comprising first, second, third, fourth, and fifth lenses disposed in order from an object, wherein: an iris is disposed between the third lens and the fourth lens; the fourth lens is formed of infrared ray absorbing glass; and the ratio (f4) of the focal length (f4) of the fourth lens to the effective focal length (EFL) of the lens system is in the range of 2.10 to 2.25. Provided are: a wide-angle lens system for the purpose of performing an infrared ray blocking function by producing a spherical or aspheric lens from blue glass containing an infrared ray blocking material, instead of an infrared ray blocking filter, and comprising same in a lens assembly; and a vehicle camera provided with the wide-angle lens system.

Description

Wide angle lens system and vehicle camera having same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small amount of light weight, high quality and light weight wide angle lens system, and a vehicle camera which can be used in a vehicle front, rear, left and right monitoring, and the like.

In general, mobile terminals, computers, laptops, and vehicles are equipped with a camera to display or record video information of surroundings, and according to the tendency of mobile terminal slimming or miniaturization of computers or laptops It is required to have a small size, light weight and high image quality, and a small size, light weight, high quality camera is required for a vehicle camera so as not to disturb the aesthetics of the driver's field of view. Such a camera should be able to obtain a wide range of image information as much as possible by having a small, lightweight, high-definition and large wide angle of view. However, while the size of the camera has been miniaturized, attempts to maintain a wide angle of view in order to obtain a wide range of image information have emerged as a problem of increasing the distortion of the wide-angle lens.

On the other hand, the image sensor of the camera generally has the characteristic that the pixel of the sensor is sensitive to the infrared spectral region. The optical system of the camera module, in which the optical component is formed of a standard glass or plastic material, has an infrared transmittance, wherein the infrared rays reaching the sensor cause undesirable color and luminance distortion. For this reason, the camera module is usually equipped with an infrared filter. Common infrared filters are interference filters. In the case of such a filter, the infrared shielding coating is applied to the flat glass, and the infrared blocking coating is coated in several layers by the coating design. The multilayer coating filter is configured to reflect infrared light and transmit visible light. Since the multilayer coating filter is designed based on light incident to the coating layer in the coating design, redness may occur in the center of the screen or sensor surface due to other transmission characteristics when light is incident on the coating layer. In addition, ghost images may occur due to multiple conference reflections. As such, the multilayer coating filter is sensitive to the incident angle of light.

As an alternative to this, an infrared absorbing glass is provided as the infrared filter. Infrared absorbing glass can solve the above problems because infrared light is absorbed while passing through the glass. However, when a light incidence angle is wide, such as a wide angle lens for a vehicle, color shading may occur due to a difference in color at the center and the periphery of the image due to the difference in the light incidence angle. In addition, in the case of a small camera module, the infrared absorption filter must be disposed in the lens system, and the space available in the lens system is very limited, so when the infrared filter is separately placed, it occupies space and hinders miniaturization. When the infrared absorbing glass is made into a flat plate and UV-bonded to the barrel end, there is a possibility that vibration and shock generated during long-term vehicle operation may deviate from the UV-bonded infrared filter.

The present invention has been made to solve the above problems, an object of the present invention is to produce a blue glass containing an infrared blocking material instead of an infrared cut filter as a spherical or aspherical lens to include in the lens assembly to perform the infrared blocking function. will be.

It is also an object of the present invention to provide a lens system comprising an infrared absorbing glass which exhibits good color characteristics irrespective of the angle of incidence in a lens system having a wide wide angle.

A wide-angle lens system according to an embodiment of the present invention for achieving the above object includes a first, second, third, fourth, and fifth lens disposed in order from the object side. The fourth lens is formed of infrared absorbing glass. The ratio f4 of the focal length f4 of the fourth lens to the effective focal length EFL of the lens system is in the range of 2.10 to 2.25.

The first lens may have a hemisphere (CA / R) value of 92% to 95% of the imaging surface side.

The lens system for a camera of the vehicle is characterized in that it has a waterproof structure including an O-ring made of silicon material.

The wide-angle lens system according to another embodiment of the present invention includes first, second, third, fourth, and fifth lenses arranged in order from the object side. The first lens has negative refractive power with a convex surface on the object side. It has negative refractive power, having a concave surface on the second lens object side and a concave surface on the imaging surface side. The third lens has a convex surface on the object side and a convex surface on the image plane side and has positive refractive power. The fourth lens has a positive refractive power as a convex lens. The fifth lens has a negative refractive ability while having a concave surface on the object side and a convex surface on the imaging surface side. The fourth lens is formed of an infrared absorbing glass.

In this case, the ratio f4 / EFL of the focal length f4 of the fourth lens and the effective focal length EFL of the lens system may be in the range of 2.10 to 2.25.

In addition, the first lens may be a glass lens, and the second lens, the third lens 330, and the fifth lens may be a plastic lens.

In another aspect of the present invention, there is provided a vehicle camera having the wide-angle lens system.

The first to fifth lenses 110, 120, 130, 140, and 150 may be disposed in the barrel. The barrel includes a first seating portion accommodating the first lens, a second seating portion accommodating the second lens, a third seating portion 213 accommodating the third lens, and the fourth lens. And a fourth seating unit accommodating the fifth lens. When the inner diameter of the first seated portion is r1, the inner diameter of the second seated portion is r2, the inner diameter of the third seated portion is r3, and the inner diameter of the fourth seated portion is r4, r1> r2> r3 It is preferred that> r4.

According to the embodiment of the present invention configured as described above, it is possible to configure a lens assembly that blocks infrared rays by using a lens having an infrared absorption function, the color characteristics are good and the ghost image is generated regardless of the change of the incident angle It is possible to remarkably prevent the occurrence of color shading.

1 is a cross-sectional view showing a lens system according to a first embodiment of the present invention.

2 is an exploded cross-sectional view of the lens system of FIG. 1.

3 is a cross-sectional view illustrating a lens system according to a second exemplary embodiment of the present invention.

4 is an exploded cross-sectional view of the lens system of FIG. 2.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

In the following lens configuration, the thickness, size, and shape of the lens have been somewhat exaggerated for explanation, and in particular, the shape of the spherical or aspherical surface shown in the lens configuration is merely an example and is not limited thereto.

Hereinafter, an embodiment of a lens system for a camera according to the present invention will be described in detail with reference to the accompanying drawings, in the following description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and duplicated thereto. The description will be omitted.

First Embodiment

1 is a diagram of a vehicle camera according to a first embodiment of the present invention, and a wide-angle lens system provided therein and displaying a light path thereof. 2 is an exploded cross-sectional view of FIG.

As shown, the vehicle camera according to the first embodiment of the present invention is a wide-angle lens system 100, consisting of a barrel 210 and the first to fifth lenses (110,120,130,140,150) disposed inside the barrel (210) And a retainer 220 coupled to the first and second spacers 240, the O-rings 230, the iris 250, and the barrel 210. The components constituting the lens system are discs, cylinders or rings, and have a cylindrical outer circumferential surface.

As shown, the wide-angle lens system 100 of the lens system according to the first exemplary embodiment of the present invention includes the first lens 110, the second lens 120, The third lens 130, the fourth lens 140, and the fifth lens 150 are included.

The first lens 110 preferably uses a glass lens. The second lens 120, the third lens 130, and the fifth lens 150 may preferably use a plastic lens. The fourth lens 140 preferably uses a glass mold lens. The wide-angle lens system 100 according to the first embodiment of the present invention is composed of one glass lens, one glass mold lens, and three plastic lenses.

The wide-angle lens system 100 according to the first embodiment of the present invention may be used as a rear camera of a vehicle by having an angle of view of up to 140 ° and an effective focal length EFL within a set range.

The wide-angle lens system 100 according to the first embodiment of the present invention has a temperature range of -40 ° C to + 85 ° C, which is a temperature range of Grade 3 of AEC-Q100, which is a temperature reliability evaluation standard for automotive electronic parts for use in a vehicle camera. Temperature correction must be applied. That is, the lens should be configured to maintain the focal point of the lens within the set range even when the lens expands or contracts with the change of temperature. When the total effective focal length EFL becomes 1.295 mm and the first lens 110 to the fifth lens 150 are configured by applying the above-described temperature correction, the first lens 110 to the fifth lens 150 are as follows.

LENS	Surface	Radius	Thickness	Material	Semi-Aperture	EFL
First lens	R1	11.550	0.800	773.496	4.610	-4.610
	R2	2.640	2.239		2.470
Second lens	R3	-6.021	0.800	530.558	2.390	-1.934
	R4	1.293	0.521		1.820
Third lens	R5	2.020	3.000	632.233	1.770	2.771
	R6	-5.603	0.648		1.260
Fourth lens	R7	3.548	2.053	589.612	1.460	2.848
	R8	-2.500	0.100		1.630
Fifth lens	R9	-3.399	2.244	632.233	1.550	-233.339
	R10	-4.369	2.000		1.920

      The first lens 110 preferably uses a meniscus lens having a convex surface on the object side and having a negative focal length. The first lens 110 preferably has a focal length of −4.610 mm. As for the first lens 110, an aspherical lens is preferably used. The first lens 110 may be processed such that the R2 surface on the imaging surface side is in the range of 92 to 95% of the hemisphere (CA / R), which is a ratio of effective semi-aperture (CA) to curvature (R: Radius). . When the hemisphere is formed as described above to improve the processability of the lens. The R2 plane hemisphere of the first lens 110 is most preferably 93.6% according to CA / R × 100 = 2.47 / 2.640 × 100 = 93.6%.

The second lens 120 preferably uses a lens having a focal length of −1.934 mm, a concave surface on the object side, and a concave surface on the imaging surface side. The third lens 130 preferably uses a convex lens having a focal length of +2.771 mm, a convex surface on the object side, and a convex surface on the image plane. The fourth lens 140 preferably uses a convex lens having a focal length of +2.848 mm. The fifth lens 150 preferably uses a lens having a focal length of -233.339 mm, a concave surface on the object side, and a convex surface on the image plane.

The wide-angle lens system 100 according to the exemplary embodiment of the present invention uses a lens having an infrared blocking effect for the fourth lens 140 without placing a filter separately for infrared blocking.

The fourth lens 140 may be made of a self-made blue glass having an infrared ray blocking effect. The fourth lens 140 preferably includes a focal length / overall effective focal length of the fourth lens and an f4 / EFL of 2.10 to 2.25 mm. The f4 / EFL of the fourth lens according to the first embodiment is 2.199. When the fourth lens 140 is configured as described above, as shown in FIG. 1, the blue glass lens is disposed in a section closest to a straight line to prevent ghost images or color shading. It becomes possible.

The barrel 210 has a hollow structure as shown in the drawing, so that the first to fifth lenses 150, the first and second spacers 240 and 260, the O-ring 230, and the iris 250 are disposed inside the barrel 210. ) May be provided with a space for mounting.

The barrel 210 includes a first seating portion 211, a second seating portion 212, a third seating portion 213, and a fourth seating portion 214. The first seating part 211 accommodates the first lens 110. The second seating part 212 receives the second lens 120. The third seat 213 accommodates the third lens 130 and the iris 250. The fourth seat 214 accommodates the fourth lens 140 and the fifth lens 150.

The inner surface of the first seating portion 211 has a diameter r1 corresponding to the diameter of the first lens 110 to accommodate the first lens 110. The inner surface of the second seating portion 212 has a diameter r2 corresponding to the diameter of the second lens 120 to accommodate the second lens 120. The inner surface of the third seating portion 213 has a diameter r3 corresponding to the diameter of the third lens 130. The inner surface of the fourth seating portion 214 has a diameter r4 corresponding to the diameters of the fourth and fifth lenses 140 and 150. The third lens 120 and the iris 250 accommodated in the third seating part 213 have the same outer diameter, and the fourth lens 140 and the fifth lens 150 accommodated in the fourth seating part 214. And the second spacer 160 preferably has the same outer diameter. It is preferable that it is comprised from r1> r2> r3> r4.

The first protrusion 215 is formed between the first seating portion 211 and the second seating portion 212 of the barrel 210, and the second seating portion 212 is formed by the first protrusion 215. If the height of the first protrusion 215 is lower than the height of the second lens 120 disposed on the second seating part 212, a space is formed between the outer circumferential surface of the second lens and the first seating part 211. O-ring 230 is disposed in this space. The size protruding toward the inner core of the first protrusion 215 corresponds to the thickness of the O-ring 230 so that the O-ring 230 may be fitted. The second seating portion 212 and the third seating portion 213 having different apertures, and the third seating portion 213 and the fourth seating portion 214 are inclinedly connected to perform the mounting process of the wide-angle lens system 100. It is desirable to facilitate. A second protrusion 216 is formed on the bottom surface of the barrel 210 to support the fifth lens 150.

A first spacer 140 is disposed between the second lens 120 and the third lens 130, an iris 250 is disposed between the third lens 130 and the fourth lens 140, and a fourth The second spacer 260 is disposed between the lens 140 and the fifth lens 150. The first spacer 240 and the second spacer 260 are formed in an annular plate shape, and are disposed between the plastic lenses or between the plastic lenses and the glass mold lenses to prevent flare. The iris 250 is disposed between the third lens 130 and the fourth lens 140 to adjust the amount of light.

Second Embodiment

On the other hand, Figure 3 is a cross-sectional view showing a wide-angle lens system and a vehicle camera including the same according to a second embodiment of the present invention. 4 is an exploded cross-sectional view of FIG. 3. The lens system according to the second embodiment shown may be applied to an around view camera mounted on a vehicle.

As shown, the vehicle camera according to the second embodiment of the present invention includes a barrel 410, a wide-angle lens system 300 composed of the first to fifth lenses 310, 320, 330, 340, 350 disposed inside the barrel 410, The first and second spacers 440 and 460, the O-ring 430, the iris 450, and the retainer 420 may be coupled to the upper portion of the barrel 410. The components constituting the wide-angle lens system are discs, cylinders or rings, and have a cylindrical outer circumferential surface.

As shown in the drawing, the wide-angle lens system 300 according to the second exemplary embodiment of the present invention includes the first lens 310, the second lens 320, and the third lens in order from the object side to the image sensor 270 imaging plane side. 330, a fourth lens 340, and a fifth lens 350.

The first lens 310 preferably uses a glass lens. The second lens 320, the third lens 330, and the fifth lens 350 may preferably use a plastic lens. As the fourth lens 340, a glass mold lens is preferably used.

The wide-angle lens system 300 according to the second embodiment of the present invention is composed of one glass lens, one glass mold lens, and three plastic lenses. The lens system according to the second embodiment as described above has an angle of view of 190 ° and an effective focal length (EFL) is configured within a setting range, so that the lens system may be applied to an around view camera of a vehicle.

The optical lens system 300 according to the second embodiment of the present invention has a temperature range of -40 ° C to + 85 ° C, which is a temperature range of Grade 3 of AEC-Q100, which is a temperature reliability evaluation standard for automotive electronic parts, for use in a vehicle camera. Temperature correction must be applied. When the total effective focal length EFL is 1.080 mm and the first lens 310 to the fifth lens 350 are configured by applying the above-described temperature correction, the first lens 310 to the fifth lens 350 are as follows.

LENS	Surface	Radius	Thickness	Material	Semi-Aperture	EFL
First lens	R1	13.360	1.000	773.496	5.400	-4.899
	R2	2.853	2.580		2.690
Second lens	R3	-7.211	0.800	530.558	2.567	-2.394
	R4	1.599	0.545		2.038
Third lens	R5	3.094	1.943	632.233	2.025	4.233
	R6	-14.960	2.203		1.674
Fourth lens	R7	2.253	1.984	589.612	1.350	2.343
	R8	-2.400	0.100		1.379
Fifth lens	R9	-2.400	0.800	632.233	1.304	-9.545
	R10	-4.500	2.788		1.325

The first lens 310 may be a meniscus lens having a focal length of −4.899 mm. The first lens 310 is preferably processed so that the hemisphere (CA / R) is in the range of 92 to 95% of the R2 surface on the imaging surface side. When the hemisphere is formed as described above to improve the processability of the lens. The R2 plane hemisphere of the first lens 310 is most preferably 94.3% according to Ca / R × 100 = 2.69 / 2.853 × 100 = 94.3%.

As for the second lens 320, it is preferable to use an aspherical lens having a focal length of -2.394 mm and an object side being concave and an image plane being concave.

The third lens 330 preferably has an aspherical lens having a focal length of +4.233 mm and an object side is convex and an image plane is convex.

As for the fourth lens 340, an aspherical lens having a focal length of +2.343 mm and having an image plane side convex and an object side convex is preferable.

As for the fifth lens 350, it is preferable to use an aspherical lens having a focal length of -9.545 mm and an object side being concave and an image plane being convex.

The wide-angle lens system 300 according to the exemplary embodiment of the present invention uses the lens of the infrared blocking material as the fourth lens 340 without disposing a separate filter for blocking the infrared rays. It is preferable that the fourth lens 340 is made of a self-made blue glass having an infrared ray blocking effect. The fourth lens 340 preferably has a focal length / overall effective focal length of the fourth lens and f4 / EFL of 2.10 to 2.25 mm. The f4 / EFL of the fourth lens according to the embodiment is 2.169.

When the fourth lens 340 is configured as described above, as shown in FIG. 6, the blue glass lens is disposed in a section where the optical path is closest to the straightest line to significantly prevent the ghost image from being generated or the color shading phenomenon. It becomes possible.

The barrel 410 has a hollow structure as shown, so that the first to fifth lenses 310, 320, 330, 340, 350, the first and second spacers 340, 360, the O-ring 330, and the iris 350 are disposed inside the barrel 410. ) May be provided with a space for mounting.

The inner diameter of the barrel 410 may include a first seat 411 accommodating the first lens 310, a second seat 412 accommodating the second lens 320, a third lens 330, and an iris ( And a third seating portion 413 accommodating the 450, and a fourth seating portion 414 accommodating the fourth lens 340 and the fifth lens 350. The first seating portion 411 has a diameter r1 corresponding to the diameter of the first lens 310 to accommodate the first lens 310, and the second seating portion 412 supports the second lens 320. The third mounting portion 413 has a diameter r3 corresponding to the diameter of the second lens 320, and the third mounting portion 413 has a diameter r3 corresponding to the diameter of the third lens 330. 414 has a diameter r4 corresponding to the diameters of the fourth and fifth lenses 140 and 150. The third lens 120 and the iris 450 accommodated in the third seating part 413 have the same outer diameter, and the fourth lens 340 and the fifth lens 350 accommodated in the fourth seating part 414. And the second spacer 160 preferably has the same outer diameter. It is preferable that it is comprised from r1> r2> r3> r4.

The first protrusion 415 is formed between the first seating portion 411 and the second seating portion 412 of the barrel 410, and the second seating portion 412 is formed by the first protrusion 415. An inner end portion 415a of the first protrusion 415 protrudes upward to form a space between the inner circumferential surface of the first seating portion 411 and the inner end portion 415a of the first protrusion 411. Is placed. Using the O-ring 430 made of silicon, the lens system according to the present embodiment has a watertight waterproof structure. The second seating portion 412 and the third seating portion 413 having different apertures, and the third seating portion 413 and the fourth seating portion 414 are inclinedly connected to each other to mount the wide-angle lens system 100. It is desirable to facilitate. The second protrusion 416 is formed on the bottom of the barrel 410 to support the fifth lens 350.

A first spacer 440 is disposed between the second lens 320 and the third lens 330, an iris 450 is disposed between the third lens 330 and the fourth lens 340, and a fourth The second spacer 460 is disposed between the lens 340 and the fifth lens 350. The first spacer 440 and the second spacer 460 are formed in an annular plate shape and disposed between the plastic lenses or between the plastic lenses and the glass mold lenses to prevent flare. The iris 450 is disposed between the third lens 330 and the fourth lens 340 to adjust the amount of light.

In the lens system according to the embodiments of the present invention configured as described above, a blue glass lens having an infrared ray blocking function is disposed on a fourth lens positioned next to the iris, so that color characteristics are good and ghost images are independent of changes in incident angle. Generation or color shading phenomenon can be prevented remarkably. In addition, the lens system according to the embodiments of the present invention can maintain the focus of the lens within the set range even in the temperature range of the electrical component of the vehicle. In addition, the lens system according to the embodiments of the present invention may have a water-tight waterproof structure by adopting an O-ring made of silicon. In addition, in the lens system according to the embodiment of the present invention, the R2 surface of the first lens has an imaging area (CA / R) of 92 to 95% in which the effective semi-Aperture to Radius ratio is in the range. It is designed so that the processability of the lens is good, and the distortion projection method of the lens is determined to have stereographic or f-theta (fθ) characteristics.

The present invention can be applied to a camera capable of showing or photographing surrounding image information in a mobile communication terminal, a computer, a notebook computer, and a vehicle.

Claims (8)

1. First, second, third, fourth, and fifth lenses disposed in order from the object side,

   The fourth lens is formed of infrared absorption glass

   And the ratio f4 / EFL of the focal length f4 of the fourth lens to the effective focal length EFL of the lens system is in the range of 2.10 to 2.25.
2. The method of claim 1,

   The first lens has a hemisphere (CA / R) value at the image plane side ranging from 92% to 95%.
3. The method of claim 1,

   The lens system is a wide-angle lens system having a waterproof structure further comprises a silicon O-ring.
4. First, second, third, fourth, and fifth lenses disposed in order from the object side,

   The first lens has a negative refractive ability having a convex surface on the object side,

   Having a concave surface on the second lens object side and a concave surface on the imaging surface side, has a negative refractive power,

   The third lens has a positive refractive power while having a convex surface on the object side and a convex surface on the imaging surface side,

   The fourth lens has a positive refractive power as a convex lens,

   The fifth lens has a negative refractive ability while having a concave surface on the object side and a convex surface on the imaging surface side,

   The fourth lens is a wide-angle lens system formed of an infrared absorption glass.
5. The method of claim 4, wherein

   And the ratio f4 / EFL of the focal length f4 of the fourth lens to the effective focal length EFL of the lens system is in the range of 2.10 to 2.25.
6. The method of claim 4, wherein

   The first lens is a glass lens (glass lens),

   The second lens, the third lens (330) and the fifth lens is a wide-angle lens system, characterized in that the plastic lens (plastic lens).
7. A vehicle camera comprising the wide-angle lens system of any one of claims 1 to 6.
8. The method of claim 7, wherein

   The first to fifth lenses 110, 120, 130, 140, and 150 are disposed inside the barrel.

   The barrel includes a first seating portion accommodating the first lens, a second seating portion accommodating the second lens, a third seating portion 213 accommodating the third lens, and the fourth lens. And a fourth seat for accommodating the fifth lens,

   When the inner diameter of the first seating portion is r1, the inner diameter of the second seating portion is r2, the inner diameter of the third seating portion is r3, and the inner diameter of the fourth seating portion is r4, r1> r2> r3 > r4 is a vehicle camera.

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