KR0126224B1 - Camera lens for ccd - Google Patents

Abstract

the first negative meniscus type lens(2) having convex surface against object; the second positive menicus type lens(4) having convex surface against object; the third positive menicus type lens(6) having convex surface against image; the forth convex lens(8) having both convex surfaces against object and image; the fifth concave lens(9) having both concave surfaces against object and image; is disclosed. Said second and third lenses(4,6) are opposed each other in both sides of a fixing iris(5) in the same conditions. Said forth and fifth lenses(8,9) are contacted to each other. Thereby, it is possible to reduce costs and to enhance productivity

Description

CCD camera lens

1 is a perspective view showing an embodiment of the present invention.

2 is a cross-sectional view of FIG.

3 is an arrangement diagram of lenses used in the present invention.

4 is a cross-sectional view of a main portion of a state in which the lens of the present invention is installed in a CCD.

* Description of the symbols for the main parts of the drawings *

2: first lens 4: second lens

5: fixed aperture 6: third lens

8: fourth lens 9: fifth lens

10: lens barrel 11: hanging groove

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a camera lens for a CCD (solid-state imaging device) used in a video door phone, a video phone camera, a closed circuit (CCTV) camera, and the like. The present invention relates to a CCD camera lens that sends an image of an object to an optical sensor CCD at a wide angle of view (78 °) up to (infinity) so that a clear image can be obtained by a TV monitor.

Conventional closed-circuit (CCTV) camera lens has a low depth of focus and the drawback of not being able to obtain a clear image from near to far at the same time, and the inconvenience of having to adjust the focal length according to the distance.

In addition, the conventional lens bundle has a complex structure and a large number of parts to be assembled, so that a large volume is produced and a lot of materials are required. The need for this has been a factor in many cost increases.

In particular, as the current user demand demands miniaturization and weight reduction of the lens, the conventional lens is increasingly being specified.

The present invention has been invented to solve the above-mentioned many problems, that is, to provide a lens that can obtain a clear image from a short distance to a long distance while improving productivity by simplifying the structure of the lens.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, detailed technical configurations and effects of the present invention will be described in detail with reference to the accompanying drawings.

CCD camera lens assembly (A) of the present invention is the lens cap (1), the first lens (2), the first spacing ring (3), the second lens (4) for holding the lens off as shown in FIG. 5 groups of 5 elements assembled with a fixed aperture (5), a third lens (6), a third gap ring (7), a fourth lens (8), a fifth lens (9), and a lens barrel (10) It consists of (5 COMPONENTS, 5 ELEMENTS).

At this time, the first lens 2 is a negative meniscus lens having a convex surface on the object side, and the second lens 4 is a positive meniscus lens having a convex surface on the object side, The third lens 6 is a positive meniscus type having a convex surface on the image side, and the fourth lens 8 has a convex surface on the object side and the image side. The fifth lens 9 should be composed of a concave lens having concave surfaces on the object side and the image side.

In addition, the second lens 4 and the third lens 6 should be installed to face each other with the fixing iris 5 interposed therebetween under the same conditions, and the fourth lens 8 and the fifth lens. The lens 9 is configured to be in contact with each other without a gap ring to maintain the lens gap.

In addition, a rubbing groove 11 is formed on the outer circumferential surface of the lens barrel 10, which is intended to insert the tightening screw 15 of the lens holder 14 when the lens barrel 10 is installed in the lens holder 14.

The process of installing the lens bundle A of the CCD camera of the present invention configured as described above is as follows.

The CCD 13 and the lens holder 14 which are connected to the TV monitor are both mounted on the PCB board 12 as shown in FIG. 4, and the lens bundle is usually in the lens holder 14 of the CCD 13 described above. Is installed.

However, when the lens bundle A of the present invention is installed in the lens holder 14, the front plate shown on the TV monitor which focuses on the focal point with the front side TARGET 16 of the object side 1-2m facing forward ( Visually inspect the resolution chart of 16) and tighten the tightening screw 15 screwed to the lens holder 14 in the clearest state.

Then, the tip of the tightening screw 15 is secured to the lens barrel 10 while being inserted into the recessed groove 11 recessed at the periphery of the lens barrel 10, so that the lens bundle A of the present invention has the best clear image. It is fixed to the lens holder 14 under the condition that can be obtained.

That is, the first lens 2 of the negative meniscus type having a convex surface on the object side of the lens bundle A of the present invention fixed to the lens holder 14 as described above makes the angle of view wide and the object. A positive meniscus type second lens 4 having a convex surface on the side reduces chromatic aberration caused by accepting a wide angle at the first lens 2.

And a third meniscus-type positive lens having a convex surface on the image side, a convex fourth lens 8 having a convex surface on the object side and an image side, an object side and an image. The fifth lens 9 of the concave type having a concave surface on the) side has the focal length and main performances of the lens (spherical aberration, coma aberration, astigmatism, curvature, chromatic aberration, image curvature, etc.) give.

As an example, assuming that the focal length (EFL) is 100, the aperture ratio (F.NO) is 1.8, and the angle of view (FA) is 78 °, the design values of the lenses described above, that is, the radius of curvature R, the thickness and the interval ( d), refractive index (n) and dispersion coefficient (ν) are as follows.

This invention is the effective diameter dl (mm), the spherometer (SPHEROMETER) measured the diameter of the fixed aperture (5) in the PROFELE PROJECTOR, the focal length measurement of the entire lens system fe (mm), the rear focal length fb (mm), The angle of view measured value θ by the projector, and the center (CR) and periphery (PR) of the resolution

Aperture 1: 8 ± 5%

Focal Length (fe): 4.4 ± 0.3

Rear focal length (fb): 4.19 ± 0.3

Angle of view (θ): 78 ° ± 5%

Resolution center (CR): 100 or more / mm

Peripheral (PR): 40 or more

If the above conditions are satisfied, the image of the object can be sent to the optical sensor CCD at a wide angle of view (78 °) from near (30 cm) to far (infinity), so that the image is clear on a TV monitor. You will get

As described above, the present invention can be used in various applications such as CCTV cameras, video door phones, video phones, home automation, etc., as the lens bundle A can be made simple and light in weight.

In addition, the process of combining with electronic components such as PCB boards is very simple, and the effect of material saving is greater than that of conventional CCTV camera lenses. The labor cost reduction and production cost reduction effect can be seen as much as possible, which can significantly improve the product's external competitiveness.

Claims (2)

In a CCD camera lens in which several lenses are assembled between the lens cap 1 and the lens barrel 10, the first lens 2 is in turn a negative MENISCUS type having a convex surface on the object side. As the lens, the second lens 4 is a positive meniscus lens having a convex surface on the object side, and the third lens 6 is a positive meniscus lens having a convex surface on the image side. The fourth lens 8 is a CONVEX type lens having convex surfaces on the object side and the image side, and the fifth lens 9 has a concave surface on the object side and the image side. The second lens 4 and the third lens 6 are installed in opposite states with the fixed aperture 5 interposed therebetween under the same conditions. A four-lens (8) and a fifth lens (9) is a CCD camera lens, characterized in that to maintain the lens interval in contact with each other without a gap ring. The effective diameter dl (mm) measured by the PROFILE PROJECTOR, the spherometer (SPHEROMETER), the focal length measurement value fe (mm) of the whole lens system, and the rear focal length fb (mm). ), Angle of view measurement θ by the projector, and center (CR) and periphery (PR) of the resolution measurement Aperture 1: 8 ± 5% Focal Length (fe): 4.4 ± 0.3 Rear focal length (fb): 4.19 ± 0.3 Angle of view (θ): 78 ° ± 5% Resolution center (CR): 100 or more / mm Peripheral (PR): 40 or more CCD young camera lens characterized by satisfying the conditions.