KR100934719B1 - Omnidirectional optics and camera system having the same - Google Patents

Abstract

PURPOSE: An omni-directional optical system and an omni-directional camera with the same are provided to reduce the volume and weight through easiness of design and simplification of a structure. CONSTITUTION: Incident light is refracted through a refraction unit(113) of a catadioptric lens(110). The first reflecting unit(123) reflects the refracted incident light toward the central part of a refraction unit. The second reflecting unit(124) reflects the reflected incident light to a relay lens unit(130). A transmission unit(125) transmits the light reflected from the second reflecting unit. A pentaprism(140) includes a reflecting unit(141) to reflect the incident light passing through the relay lens unit in the right angle direction.

Description

Omnidirectional optics and camera system having the same

The present invention relates to an omnidirectional optical system, and more particularly, to an omnidirectional optical system and a omnidirectional camera having a omnidirectional optical system designed to view 360 degrees by applying a catadioptric lens.

In general, a panoramic camera that captures a view of 360 ° in all directions in one photograph at a scenic tourist spot is an example of an omnidirectional imaging system. The omnidirectional imaging system refers to an imaging system that captures all of the scenery seen by an observer as they turn around. In contrast, a system that captures a single view of the landscape in all directions that can be viewed from the viewer's location is called an omnidirectional imaging system.

In the omnidirectional imaging system, the observer not only turns around in place, but also includes all the scenery that can be viewed by tilting or leaning his head. Mathematically, the solid angle of a region that can be captured by an imaging system refers to a case of 4π steradian.

Omnidirectional imaging systems and omnidirectional imaging systems are not only traditional applications such as photography of buildings, natural landscapes and celestial bodies, but also charge-coupled devices (CCDs) and complementary metal-oxide-semiconductors (CMOS). BACKGROUND ART Many studies and developments have been carried out for applications in security and surveillance systems using cameras, virtual tours of real estate, hotels, and tourist attractions, or mobile robots or unmanned aerial vehicles.

As a method of obtaining an omnidirectional image, research on a catadioptric omnidirectional imaging system combining a mirror and a lens has been actively conducted.

1 is a conceptual diagram of a general reflective refractive omnidirectional imaging system.

Referring to FIG. 1, the conventional reflective refractive omnidirectional imaging system 10 has a rotationally symmetrical omnidirectional mirror 11 having a cross-sectional shape close to a hyperbola and a rotationally symmetrical axis 11a of the mirror 11. It is composed of an image acquisition means comprising a lens 12 positioned and facing the mirror 11 and a camera body 14 having an image sensor 13 therein.

At this time, the incident light from the object is incident toward the rotational symmetry axis 11a in all directions 360 ° around the mirror 11, and the incident light 10a having an altitude angle δ is one point on the mirror surface 11. It is reflected by M and captured by the image sensor 13 as reflected light 10b having a zenith angle θ with respect to the rotational symmetry axis 11a. Here, the elevation angle refers to the angle measured from the horizontal plane (ie, the X-Y plane) toward the zenith.

Another way to obtain an omnidirectional image is to use a fisheye lens with a wide angle of view. For example, a fisheye lens with an angle of view of 180 ° can be pointed vertically into the sky to capture a single image from the sky constellation to the horizon. For this reason, fisheye lenses are also referred to as all-sky lenses.

In particular, a Nikon fisheye lens (6mm f / 5.6 Fisheye-Nikkor) reaches an angle of view of 220 °, so when attached to the camera, some of the scenery behind the camera can be included in the image. In this way, an omnidirectional image may be obtained from an image obtained by using a fisheye lens.

In many cases, the imaging system is mounted on a vertical wall. This may be the case, for example, with a video system installed on the exterior wall of a building to monitor the perimeter of the building, or a rear camera for monitoring the rear of a car. In this case, if the horizontal angle of view is much larger than 180 °, the efficiency is rather low. This is because the wall, which requires little monitoring, occupies a lot of the screen, so the image looks boring and the pixels are wasted. Therefore, in this case, it is preferable that the angle of view in the horizontal direction is about 180 degrees.

However, for this purpose, it is not preferable to use a fisheye lens having an angle of view of 180 °. Because fisheye lenses produce barrel distortions, they cause aesthetic displeasure and are ignored by consumers.

An example of an imaging system that can be attached to one wall of a room to monitor the entire room is a pan, tilt, or zoom camera. Such a camera is realized by attaching a video camera equipped with an optically zooming lens to a pan / tilt stage.

The pan action refers to a function that can rotate by a predetermined angle in the horizontal direction, and the tilt action refers to a function that can rotate by a predetermined angle in the vertical direction. In other words, when the camera is in the center of the celestial sphere describing the object, the pan means the operation of changing the longitude, and the tilt means the operation of changing the latitude.

Therefore, the theoretical range of pan action is 360 ° and the theoretical range of tilt action is 180 °. Disadvantages of such pan, tilt and zoom cameras include high cost, large volume and weight.

Lenses with optical zoom are bulky, heavy and expensive due to the complexity of the design and the complexity of the structure. In addition, the pan tilt stage is an expensive device comparable to a camera. Therefore, the installation of a pan, tilt, zoom camera has to pay a considerable amount of money. In addition, since the pan tilt zoom camera is bulky and heavy, it can be a significant obstacle depending on the application. For example, when the weight of a payload is very important, such as an airplane, or when space constraints exist to install an imaging system in a narrow space. Moreover, since the pan tilt motion is a physical action, it takes a long time to perform such an action.

The present invention is to solve the above-mentioned problems, due to the ease of design and simplicity of the structure can be manufactured in a small volume, light weight and low price, can be installed in a narrow space, so there is almost no space constraint The present invention does not have a physical action such as pan, tilt, and zoom, and thus provides an omnidirectional optical system having a very fast operation response speed and an omnidirectional camera having the omnidirectional optical system.

In order to achieve the above object, the omnidirectional optical system according to the first embodiment of the present invention has a refracting part in which incident light is refracted, and an inner surface facing the refracting part so as to reflect the refracted incident light toward the center of the refracting part. The first reflecting portion to be formed, the second reflecting portion formed on the inner surface of the central portion of the refracting portion so as to reflect the incident light reflected through the first reflecting portion to the relay lens unit to transmit the light reflected from the second reflecting portion A Catadioptric lens comprising a transmission portion; A relay lens unit for condensing and imaging incident light refracted, reflected, and transmitted from the refracting portion, the first reflecting portion, the second reflecting portion, and the transmitting portion; And a pentaprism having a reflection portion formed on an inner surface thereof so that the incident light passing through the relay lens unit can be reflected at right angles. The field angle of the catadioptric lens is 360 degrees left and right, and up and down 45 degrees. It is characterized by being ~ 55 degrees.

In addition, the field angle of the catadioptric lens is characterized in that the left and right 360 degrees, up and down 53 degrees (upper 37 degrees, lower 16 degrees).

In the above-described configuration, the relay lens unit has a first lens installed at the rear of the Catadioptric lens, a second lens installed at a predetermined distance behind the first lens, a predetermined distance at the rear of the second lens A stop is provided, a third lens installed behind the stop, a fourth lens coupled to the third lens, and the fifth lens is provided with a predetermined distance from the fourth lens, characterized in that .

On the other hand, the omnidirectional camera having an omnidirectional optical system according to the first embodiment of the present invention comprises a Catadioptric lens support; A refraction part installed inside the catadioptric lens support body, the first reflection part being formed on an inner side surface of the catadioptric lens facing the refraction part to reflect the refracted incident light toward the center part of the refraction part, and the first reflection part A catadioptric lens including a second reflecting portion formed on an inner surface of the center portion of the refracting portion and a transmitting portion for transmitting the light reflected by the second reflecting portion so as to reflect incident light reflected through the portion to the relay lens unit; A relay lens unit for condensing and imaging incident light refracted, reflected, and transmitted from the refracting portion, the first reflecting portion, the second reflecting portion, and the transmitting portion; A first housing supporting the Catadioptric lens support and the relay lens unit; A pentaprism having a reflection portion formed on an inner surface thereof so as to reflect incident light passing through the relay lens unit in a right angle direction; A second housing supporting the pentaprism; It comprises a camera body for receiving light from the penta prism, the field angle (Field Angle) of the catadioptric lens is characterized in that 360 degrees left and right, 45-55 degrees up and down.

In addition, the field angle of the catadioptric lens is characterized in that the left and right 360 degrees, up and down 53 degrees (upper 37 degrees, lower 16 degrees).

The omnidirectional optical system according to the second embodiment of the present invention includes a refracting part in which incident light is refracted, a first reflecting part formed on an inner side surface facing the refracting part to reflect the refracted incident light toward the center of the refracting part, A second reflection portion formed on an inner surface of the refraction portion central portion to reflect incident light reflected through the first reflection portion to a first relay lens unit, an irregular reflection prevention step portion formed adjacent to the first reflection portion, and the second reflection portion; A Catadioptric lens comprising a transmission portion for transmitting the light reflected by the reflection portion; A first relay lens unit for condensing and imaging incident light refracted, reflected, and transmitted from the refracting part, the first reflecting part, the second reflecting part, and the transmitting part; A triprism in which an inclined surface reflector is formed to reflect the incident light passing through the first relay lens unit in a direction perpendicular to the second relay lens unit; A second relay lens unit installed at regular intervals in a direction perpendicular to the triprism and configured to collect and image incident light reflected from the triprism; a field angle of the catadioptric lens Is characterized in that the left and right 360 degrees, up and down 45-55 degrees.

In addition, the field angle of the catadioptric lens is characterized in that the left and right 360 degrees, up and down 52 degrees (upper 38 degrees, lower 14 degrees).

The first relay lens unit may include a first lens installed behind the Catadioptric lens and a second lens installed at a predetermined distance behind the first lens, and the second relay lens unit may include the triprism. A stop disposed at a predetermined interval in a direction perpendicular to the stop, a third lens installed at the rear of the aperture, a fourth lens coupled to the third lens, and a fifth lens installed at a predetermined distance from the fourth lens. And a sixth lens installed at a predetermined distance from the fifth lens.

The configuration of the omnidirectional camera using the omnidirectional optical system according to the second embodiment of the present invention is similar to that of the omnidirectional camera system of the first embodiment.

That is, the omnidirectional camera having the omnidirectional optical system according to the second embodiment of the present invention comprises a Catadioptric lens support; A refraction part installed inside the catadioptric lens support body, the first reflection part being formed on an inner side surface of the catadioptric lens facing the refraction part to reflect the refracted incident light toward the center part of the refraction part, and the first reflection part A second reflection portion formed on an inner surface of the center portion of the refracting portion, a diffuse reflection prevention step formed adjacent to the first reflection portion, and the second reflection portion so as to reflect incident light reflected through the first reflection lens unit; A Catadioptric lens comprising a transmission portion for transmitting the light; A first relay lens unit (330) for condensing and imaging the refracted, reflected and transmitted incident light from the refracting part, the first reflecting part, the second reflecting part, and the transmitting part; A first housing supporting the Catadioptric lens support and the first relay lens unit; A triprism in which an inclined surface reflector is formed to reflect the incident light passing through the first relay lens unit in a direction perpendicular to the second relay lens unit; A second relay lens unit provided at a predetermined interval in a direction perpendicular to the triprism, for collecting and imaging incident light reflected from the triprism; A second housing supporting the triprism and the second relay lens unit; It comprises a camera body for receiving light from the second relay lens unit, the field angle (Field Angle) of the catadioptric lens is characterized in that 360 degrees left and right, 45-55 degrees up and down.

In addition, the field angle of the catadioptric lens is characterized in that the left and right 360 degrees, up and down 52 degrees (upper 38 degrees, lower 14 degrees).

The omnidirectional optical system and the omnidirectional camera having the omnidirectional optical system according to the present invention can be manufactured in a small volume, light weight, low cost, and can be installed in a narrow space due to the ease of design and simplicity of the structure. Since there is almost no restriction, and it is not a physical action like pan, tilt and zoom as in the prior art, it has an excellent effect of operating response speed very fast, and there is no physical moving part, so the response speed of the system is fast and there is a fear of mechanical failure. There is little advantage.

In addition, the present invention is designed to view 360 degrees by applying a catadioptric system, can be applied to a high resolution camera applied 2 Mega pixels to 1/3 inch or 1/4 inch sensor according to the sensor, Field Angle is Pentaprism and Tri, as well as 360 degrees left and right, up and down 45-55 degrees, preferably up and down 53 degrees (37 degrees upper, 16 degrees lower) and 52 degrees upper (38 upper, 14 lower) By applying the prism structure, it has an excellent effect of miniaturizing and greatly reducing the optical path.

Hereinafter, an omnidirectional optical system and an omnidirectional camera having the same according to a first embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of an omnidirectional optical system according to a first embodiment of the present invention.

Referring to FIG. 2, the omnidirectional optical system 100 according to the present invention includes a refracting part 113 in which incident light is refracted, and an inner surface facing the refracting part so as to reflect the refracted incident light toward the center of the refracting part. In the first reflecting portion 123 to be formed, the second reflecting portion 124 and the second reflecting portion formed on the inner surface of the central portion of the refracting portion to reflect the incident light reflected through the first reflecting portion to the relay lens unit Catadioptric lens (110) configured to include; and a transmission portion 125 for transmitting the reflected light; A relay lens unit (130) for condensing and imaging incident light refracted, reflected, and transmitted from the refracting part (113), the first reflecting part (123), the second reflecting part (124), and the transmitting part (125); And a pentaprism 140 having a reflector 141 formed on an inner surface thereof so as to reflect incident light passing through the relay lens unit in a right angle direction. The field angle of the catadioptric lens is included. Is characterized in that the left and right 360 degrees, up and down 45-55 degrees.

In addition, the field angle of the catadioptric lens is characterized in that the left and right 360 degrees, up and down 53 degrees (upper 37 degrees, lower 16 degrees).

In the above-described configuration, the relay lens unit 130 has a first lens 131 installed at the rear of the catadioptric lens 110 and a predetermined interval behind the first lens 131. The second lens 132 to be installed, the stop (stop) is provided at a predetermined interval behind the second lens 132, the third lens 133 is installed behind the aperture, the third lens 133 And a fourth lens 134 coupled to the fourth lens 134 and a fifth lens 135 installed at a predetermined distance from the fourth lens 134.

3 is a block diagram of the omnidirectional camera according to the first embodiment of the present invention.

Referring to FIG. 3, the omnidirectional camera 200 having the omnidirectional optical system according to the present invention includes a catadioptric lens support 210; A second part disposed inside the catadioptric lens support and formed on an inner surface of the catadioptric lens support opposite to the refraction part to reflect the refracted incident light toward the center part of the refraction part; The first reflector 123, the second reflector 124 formed on the inner surface of the refraction center, and the light reflected by the second reflector to reflect the incident light reflected through the first reflector to the relay lens unit. A catadioptric lens 110 including a transmission part 125 for transmitting the light; A relay lens unit (130) for condensing and imaging incident light refracted, reflected, and transmitted from the refracting part, the first reflecting part, the second reflecting part, and the transmitting part; A first housing (203) for supporting a catadioptric lens support (210) and the relay lens unit (130); A pentaprism 140 having a reflector formed on an inner surface thereof so as to reflect incident light passing through the relay lens unit in a right angle direction; A second housing 240 supporting the penta prism; It is configured to include a camera body 220 for receiving light from the penta prism.

In the omnidirectional optical system according to the first embodiment of the present invention, a catadioptric (catadioptric) system is applied to view 360 degrees, and the field angle is 360 degrees left and right, and 45 to 55 degrees up and down. It is done.

In addition, the field angle of the catadioptric lens may be 360 degrees left and right, and 53 degrees up and down (37 degrees upper and 16 degrees lower).

In addition, it can be applied to high resolution cameras with 2 Mega pixels applied to 1 / 3-inch or 1 / 4-inch CCDs, and pentaprism is applied to reduce the optical path and reduce the optical path length to about 1 / of the actual optical system length. The feature of the configuration is that the optical system fits within 20mm x 20mm, reduced by two.

Hereinafter, each detailed configuration of the omnidirectional optical system according to the first embodiment of the present invention will be described in detail.

First, as shown in FIG. 4, the catadioptric lens is composed of a first surface (refractive transmission), a second surface (reflection), a third surface (reflection), and a fourth surface (transmission). In total, it is one lens, but it is actually a complex lens composed of one lens and two mirrors.

The catadioptric lens is a system used when constructing an optical system that cannot be composed only of a lens or a mirror, and is applied to an astronomical telescope while simplifying the configuration of the optical system and improving performance.

FIG. 5 illustrates a relay lens unit. Referring to FIG. 5, in the present invention, only a catadioptric lens does not form an image. Therefore, it is necessary to make an image on the sensor by using a lens, and relaying the light to the sensor is called a relay lens, but in this system, it is designed as a system that combines with a catadioptric lens and forms an image.

The number of the relay lens may vary depending on the specification of the sensor and the number of views according to the viewing angle. In the present invention, a catadioptric lens and five relay lenses, except for pentaprism, are combined with five relay lenses to improve optical aberration. It is designed to remove and maintain image clarity using sensors up to 700,000 pixels.

6 and 7 illustrate pentaprism. 6 and 7, pentaprism is a reflective prism with five sides and is used to refract light at 90 °. Inside the pentaprism, light is reflected twice, and a normal right-angle prism lets the light pass through without flipping.

Since the angle of incidence of the light incident on the penta prism is smaller than the critical angle, the minimum angle that can cause total reflection, it does not cause total internal reflection.

Therefore, the two surfaces are coated like a mirror surface to reflect light, and the two opposite surfaces are mainly coated with an anti-reflective coating to reduce diffuse reflection (or unwanted reflection).

The fifth side of the prism is not used optically, but is cut at an appropriate angle so as not to interfere with the reflection of the two reflecting surfaces.

As described above, the pentaprism not only forms an image on the sensor without flipping the image in the optical system of the present invention, but as shown in FIG. 8, the pentaprism forms an optical path of the optical system at a right angle to form alignment with other optical components. It also facilitates and reduces the length of the optical system by about 12.8 mm.

On the other hand, as a method of determining the initial specification of the optical system, the relationship between the resolution of the CCD and the resolution of the optical system is determined by the following equation.

CCD Res. (Μm) = 2 x CCD Pixel Size (horiz, μm)

CCD Res. (Lp / mm) = #Pixels (Horiz) / 2 x Pixel Size (horiz)

Primary Mag. (PMAG) = Sensor Size (Horiz, mm) / FOV ((Horiz, mm)

System Res. (Μm) = CCD Resolution (µm) / PMAG

                = 2 x Pixel Size (㎛) x FOV (mm) / Sensor Size (mm)

System Res. (Lp / mm) = PMAG x CCD Resolution (lp / mm)

For example, when determining the specifications of a CCD camera, 1280 x 1024 Pixels, 4.65 μm Pixels Size, 1/2 inch CCD (calculated for short axis),

CCD Res. (Lp / mm) = 1024/2 x 4.8 = 106.7 lp / mm,

If the wavelength is 0.546 nm and the MTF is to be 0.4 or more at a CCD resolution of 106.7 lp / mm, then the standardized spatial frequency corresponding to MTF 0.4 is shown in the table that standardizes the deterioration of the MTF according to the spatial frequency of the optical system of the aberration circular opening. Is 1.0, so the minimum numerical aperture (NA) is

n'sinθ '≥ 0.000546 x 106.7 / 1.0 = 0.058 (F / # = 1 / 2NA)

Detailed specifications of the catadioptric lens and the relay lens unit according to the first embodiment of the present invention determined according to this method will be described below with reference to FIG. 9.

In FIG. 9, C1 (catadioptric lens) of the first embodiment of the present invention converges a wide-angle light beam, G1 emits light from C1, and G2 emits light emitted by C1 + G1 to the sensor. By reimaging, C1 + G1 + G2 has a positive-negative-positive (PNP) type of refraction, and the main plane (image plane, reference plane for measuring Efl) is outside the G2 L5 lens, and Efl ( Effective Focal Length has a negative value, Bfl has a positive value, and Bfl has a back value of Efl. It features a structure of reverse telephoto lens larger than the focal length: Back Focal Length).

As described above, the catadioptric lens has a first surface (refractive transmission), a second surface (reflection), a third surface (reflection), and a fourth surface (transmission), and the relay lens includes L1 to An L5 lens, with a stop located between L2 and L3.

In more detail, the L1 lens has a fifth surface on the object side and a sixth surface on the image side, and the L2 lens has a seventh surface on the object side and an eighth surface on the image side.

The L3 lens has an object-side tenth surface, an eleventh surface that is a coupling surface of the L3 lens and an L4 lens, an image twelfth surface of the L4 lens, an object-side thirteenth surface and an image fourteenth surface of L5.

The following table shows the optical design of the optical system of the first embodiment of the present invention, where r is the radius of curvature, d is the distance between lenses, nd is the refractive index, and vd is the dispersion value.

* Power: refractive power

9 and the above table, both the fifth and sixth surfaces of the L1 lens of the first embodiment of the present invention are both convex surfaces, and the L2 lenses are both concave surfaces (the seventh and eighth surfaces). concave surface, the tenth surface of the L3 lens is a concave surface, and the eleventh surface, which is the combined surface of the L3 and L4, is a convex surface having positive refractive power, and the twelfth surface of the L4 lens has a convex surface, and L5 The thirteenth and fourteenth surfaces of the lens are both convex surfaces.

In addition, referring to FIG. 9 and the above table, both the catadioptric lens and the L1 lens of the first embodiment of the present invention have positive refractive power, and the Abbe number of the catadioptric lens is 50 or more. to be.

The L1 lens has a high refractive index and a relatively low Abbe number of about 25, which is necessary to correct the difference in refractive power with wavelength in a Catadioptric lens, and the L4 to L5 lenses are all 50 or more. Have a high Abbe number

As described above, MTF characteristics, aberration analysis, distortion aberration characteristics analysis, and the like, which can be analyzed whether the present invention is designed according to the target specifications.

MTF is a modulation procurement function characteristic in the visible light region, and refers to the contrast ratio of a sensor when a pair or several pairs of black and white light passes through the lens, as shown in the following figure. When passed, it does not have a 100% contrast ratio in the sensor. If it is recognized as a phase, about 20% can be recognized as a phase and the designer should design a contrast ratio of about 40% or more in consideration of tolerances.

The MTF graph of the optical system according to the present invention is shown in FIG. 10. According to FIG. 10, it can be seen that the modulation at 100 lp / mm has a satisfactory contrast ratio of 40%. In other words, 100lp / mm means that there are 100 pairs of black and white in 1mm, and the sensor shows that the size of one pixel is 5um. (In the MTF graph, the vertical axis represents contrast ratio and the horizontal axis represents lp / mm. Indicates.)

In addition, there are several lines in the MTF that display incoming rays according to the size of the field of view, called optical fields. In other words, the MTF curve is designed with variables such as the number of lenses, lens material, curvature, and the distance between the lenses so that the MTF curve becomes 40% at 100 lp / mm for each field, and the graph shown in the aberration characteristics analysis when MTF 40% is satisfied. It shows how it should be designed like a family.

11 and 12 are graphs and data of finite optical astigmatism, spherical aberration, coma, and astigmatism characteristic according to three wavelengths of the omnidirectional optical system according to the first embodiment of the present invention.

As shown in FIGS. 11 and 12, it can be seen that the finite light aberration wheel satisfies the aberration within 5 μm for all fields. It can be seen that the coincidence of) is near the top end, and it satisfies the specification shown in the MTF graph of FIG. 10.

FIG. 13 shows the distortion aberration of the omnidirectional optical system according to the first embodiment of the present invention.

Next, a second embodiment of the present invention will be described.

14 is a block diagram of an omnidirectional optical system according to a second embodiment of the present invention.

Referring to FIG. 14, the omnidirectional optical system 300 according to the second exemplary embodiment of the present invention may include a refraction unit 313 in which incident light is refracted, and the refracting unit so as to reflect the refracted incident light toward the center of the refraction unit. The first reflecting portion 323 formed on the opposite inner surface, and the second reflecting portion 324 formed on the inner surface of the central portion of the refracting portion so that the incident light reflected through the first reflecting portion can be reflected to the first relay lens unit. And a catadioptric lens including a diffuse reflection prevention step portion 326 formed adjacent to the first reflection portion 323 and a transmission portion 325 for transmitting light reflected from the second reflection portion. 310; A first relay lens unit 330 for condensing and forming incident light refracted, reflected, and transmitted from the refracting part 313, the first reflecting part 323, the second reflecting part 324, and the transmitting part 325; ; A triprism 340 having an inclined surface reflector 341 formed to reflect the incident light passing through the first relay lens unit in a direction perpendicular to the second relay lens unit 350; It is installed at regular intervals in a direction perpendicular to the triprism, and comprises a second relay lens unit 350 for collecting and imaging the incident light reflected from the triprism, the field angle of the catadioptric lens ( Field Angle) is characterized by 360 degrees left and right, 45 ~ 55 degrees up and down.

In addition, the field angle of the catadioptric lens may be 360 degrees left and right, and 52 degrees up and down (38 degrees upper and 14 degrees lower).

In addition, the first relay lens unit 330 is provided with a first lens 331 installed at the rear of the catadioptric lens 310, a predetermined distance behind the first lens 331. A second lens 332, the second relay lens unit 350 is a stop (stop) is installed at a predetermined interval in a direction perpendicular to the tri-prism 340, a third lens installed behind the aperture And a fourth lens 334 coupled to the third lens 333, a fifth lens 335 and the fifth lens 335 disposed at a predetermined distance from the fourth lens 334. The sixth lens 336 is provided at a predetermined interval.

The configuration of the omnidirectional camera using the omnidirectional optical system according to the second embodiment of the present invention is similar to that of the omnidirectional camera system according to the first embodiment shown in FIG. 3.

That is, referring to FIGS. 3 and 14, the omnidirectional camera 200 having the omnidirectional optical system according to the second embodiment of the present invention includes a catadioptric lens support 210; A receptacle 313 disposed inside the catadioptric lens supporter and formed on an inner surface of the catadioptric lens support opposite to the refraction portion to reflect the refracted incident light toward the center portion of the refraction portion; The first reflector 323, the second reflector 324, and the first reflector 323, which are formed on an inner surface of the central portion of the refracting part so as to reflect incident light reflected through the first reflector to the first relay lens unit. A catadioptric lens 310 including an anti-reflective stepped portion 326 formed adjacent to the second reflection unit and a transmission unit 325 for transmitting the light reflected from the second reflection unit; A first relay lens unit 330 for condensing and forming incident light refracted, reflected, and transmitted from the refracting part 313, the first reflecting part 323, the second reflecting part 324, and the transmitting part 325; ; A first housing 203 for supporting the Catadioptric lens support and the first relay lens unit; A triprism 340 having an inclined surface reflector 341 formed to reflect the incident light passing through the first relay lens unit in a direction perpendicular to the second relay lens unit 350; A second relay lens unit (350) installed at regular intervals in a direction perpendicular to the triprism, for collecting and imaging the incident light reflected from the triprism; A second housing 240 supporting the triprism and the second relay lens unit; It characterized in that it comprises a camera body 220 for receiving light from the second relay lens unit.

In addition, it can be applied to high resolution cameras with 2 Mega pixels applied to 1 / 3-inch or 1 / 4-inch CCDs, and pentaprism is applied to reduce the optical path and reduce the optical path length to about 1 / of the actual optical system length. The feature of the configuration is that the optical system fits within 20mm x 20mm, reduced by two.

Hereinafter, each detailed configuration of the omnidirectional optical system according to the second embodiment of the present invention will be described in detail.

First, as shown in FIG. 14, the catadioptric lens is the same as the configuration of the catadioptric lens of the first embodiment of the present invention described above, except that the radius of curvature of the second and fourth surfaces is different. The same, there is a difference in that it comprises a diffuse reflection prevention step portion 326 formed adjacent to the first reflecting portion 323, which is the catadioptric lens support 210 of the first embodiment of the present invention ) To reduce light loss due to diffuse reflection of incident light.

A detailed specification of a catadioptric lens and a relay lens unit according to a second embodiment of the present invention will be described with reference to FIG. 15.

In FIG. 15, C1 (Catadioptric lens) according to the second embodiment of the present invention converges a wide-angle light beam, G1 emits light from C1, and G2 emits light emitted by C1 + G1. By imaging again on the sensor, C1 + G1 + G2 has a positive-negative-negative (PNN) refractive index, and the main plane (image plane, reference plane for measuring Efl) exists inside the G2 L6 lens, Efl (Effective Focal Length) has a positive value, Bfl (Back Focal Length) has a (+) value, and Bfl (Back Focal Length) has a value of Efl ( It is characterized by having a structure of reverse telephoto lens larger than the effective focal length).

As described above, the catadioptric lens has a first surface (refraction transmission), a second surface (reflection), a third surface (reflection), and a fourth surface (transmission).

The first relay lens unit includes L1 and L2 lenses, and a triprism is installed at a predetermined distance from the L2 lens.

In more detail, the L1 lens has a fifth surface that is the convex surface of the object side and a sixth surface that is the convex surface of the image side, and the L2 lens is the object side. It has a seventh surface which is a concave surface of and an eighth surface which is an upper concave surface.

The second relay lens unit includes L3 to L6 lenses, and a stop is positioned between the prism and the L3 lens.

The L3 lens has an eleventh plane which is the plane of the object side, a twelfth plane which is the coupling plane of the L3 lens and the L4 lens, a thirteenth plane which is the convex plane of the image of the L4 lens, a 14th plane which is the convex plane of the object side of the L5 lens, It has a fifteenth surface which is an image convex surface, and has a 16th surface which is a convex surface of the object side of an L6 lens, and a 17th surface which is an image convex surface.

The following table shows the optical design of the optical system of the second embodiment of the present invention, where r is the radius of curvature, d is the distance between lenses, nd is the refractive index, and vd is the dispersion value.

* Power: refractive power

Referring to FIG. 15 and the above table, both the Catadioptric lens and the L1 lens of the second embodiment of the present invention have positive refractive power, and the Abbe number is 50 or more.

L2 and L3 lenses have a relatively low Abbe number of about 20 to 25, which is necessary to compensate for the difference in refractive power with wavelength in both Catadioptric and L1 lenses, and L4 to L6 lenses are all It has a high Abbe number of 50 or more.

An MTF graph of the optical system according to the second embodiment of the present invention is shown in FIG. 16. According to FIG. 16, it can be seen that the graph has a satisfactory contrast ratio of 40% or more at 160 lp / mm of each field.

17 and 18 are graphs and data of finite optical astigmatism, spherical aberration, coma, astigmatism, and data according to three wavelengths of the omnidirectional optical system according to the second embodiment of the present invention. It can be seen that it is satisfied, and that the specifications shown in the MTF graph of FIG. 16 are satisfied.

19 shows distortion aberration of the omnidirectional optical system according to the second embodiment of the present invention, and it can be seen that it is relatively well corrected.

As described above, the omnidirectional optical system according to the first and second embodiments of the present invention can be manufactured in a small volume, light weight, low cost, and narrow due to the ease of design and the simplicity of the structure. Since it can be installed in the space, there is almost no space limitation, and the operation response speed is very fast because it is not a physical action like pan, tilt and zoom as in the prior art. Since there is no physically moving part, the response speed of the system is fast and there is little risk of mechanical failure.

As such, the rights of the present invention are not limited to the above-described embodiments, but are defined by the claims, and those skilled in the art can make various modifications within the scope of the claims. It is self evident.

1 is a conceptual diagram of a general reflective refractive omnidirectional imaging system

2 is a block diagram of an omnidirectional optical system according to a first embodiment of the present invention;

3 is a block diagram of an omnidirectional camera according to a first embodiment of the present invention

4 is a block diagram of a Catadioptric lens according to a first embodiment of the present invention

5 is a configuration diagram of a relay lens unit according to a first embodiment of the present invention;

6 is a pentaprism light reflection path diagram according to a first embodiment of the present invention.

7 is a configuration diagram of a pentaprism according to the first embodiment of the present invention.

8 is a length comparison diagram of the omnidirectional optical system according to the first embodiment of the present invention.

9 is a configuration diagram of an omnidirectional optical system according to a first embodiment of the present invention.

10 is an MTF graph of the optical system according to the first embodiment of the present invention.

FIG. 11 is a graph showing finite optical astigmatism, spherical aberration, coma, and astigmatism characteristics according to three wavelengths of the omnidirectional optical system according to the first embodiment of the present invention.

12 shows spherical aberration, coma, and astigmatism characteristic data of the omnidirectional optical system according to the first embodiment of the present invention.

13 is a distortion aberration diagram of the omnidirectional optical system according to the first embodiment of the present invention.

14 is a block diagram of an omnidirectional optical system according to a second embodiment of the present invention;

15 is a configuration diagram of an omnidirectional optical system according to a second embodiment of the present invention.

16 is an MTF graph of an optical system according to a second embodiment of the present invention.

FIG. 17 is a graph showing finite optical astigmatism, spherical aberration, coma, and astigmatism characteristic according to three wavelengths of the omnidirectional optical system according to the second embodiment of the present invention.

18 shows spherical aberration, coma, and astigmatism characteristic data of the omnidirectional optical system according to the second embodiment of the present invention.

19 is a distortion aberration diagram of the omnidirectional optical system according to the second embodiment of the present invention.

<Description of main part drawings>

100: omnidirectional optical system 110: Catadioptric lens 113: refractive portion

123: first reflecting portion 124: second reflecting portion 125: transmissive portion

130: relay lens unit 131: first lens 132: second lens

133: third lens 134: fourth lens 135: fifth lens

140: pentaprism 141: reflector

210: Catadioptric lens support 203: first housing

220: camera body 240: second housing

301: transparent cover refractive portion 313: Catadioptric lens refractive portion

323: first reflective portion 324: second reflective portion 325: transmissive portion

326: diffuse reflection prevention step 326 330: first relay lens unit

350: second relay lens unit

Claims (25)

A refraction part 113 in which incident light is refracted, a first reflection part 123 formed on an inner side surface facing the refracting part so as to reflect the refracted incident light toward the center part of the refraction part, and reflection through the first reflection part And a second reflector 124 formed on the inner surface of the refraction center and a transmission unit 125 for transmitting the light reflected by the second reflector so as to reflect the incident light to the relay lens unit. A catadioptric lens 110; A relay lens unit (130) for condensing and imaging incident light refracted, reflected, and transmitted from the refracting part (113), the first reflecting part (123), the second reflecting part (124), and the transmitting part (125); A pentaprism 140 having a reflector 141 formed on an inner surface thereof so as to reflect incident light passing through the relay lens unit in a right angle direction. The method of claim 1, The field angle of the catadioptric lens is 360 degrees left and right, and the omni-directional optical system, characterized in that 45 ~ 55 degrees up and down The method of claim 1, The field angle of the catadioptric lens is 360 degrees left and right, 53 degrees up and down (37 degrees upper, 16 degrees lower), the omnidirectional optical system, characterized in that The method of claim 1, The relay lens unit 130 may include a first lens 131 installed at the rear of the catadioptric lens 110, a second lens 132 installed at a predetermined distance behind the first lens 131, An aperture stop provided at a rear of the second lens 132 at a predetermined interval, a third lens 133 installed at the rear of the aperture, and a fourth lens 134 coupled to the third lens 133. And a fifth lens 135 installed at a predetermined distance from the fourth lens 134. The method of claim 1, The pentaprism 140 is a reflective prism having five sides. The pentaprism 140 may reflect light by coating two surfaces as a mirror surface so that light is reflected twice within the pentaprism, and the other surfaces except the transmissive surface. Is an anti-reflective coating to reduce diffuse reflection (or unwanted reflections) and is used to refract light to 90 ° The method of claim 4, wherein The catadioptric lens 110 converges a wide-angle light beam, the first lens and the second lens emit light from the catadioptric lens 110, and the third lens, the fourth lens, and the third lens. The 5th lens forms light rays emitted by the catadioptric lens, the first lens, and the second lens onto the sensor, whereby the catadioptric lens, the first lens and the second lens, and the third to fifth lenses. The lens has a positive-negative-positive (PNP) type refractive power, a main plane (imaging plane, a reference plane for measuring Efl) exists outside the fifth lens, and an effective focal length (Efl) is negative. , Omnidirectional optical system, characterized in that the Bfl (post-focal length) has a positive value, the Bfl (post-focal length) value is larger than the Efl (effective focal length) value structure The method of claim 4, wherein The first lens is a convex surface of both the fifth surface of the object side and the sixth surface of the image side, and the second lens is the seventh surface of the object side and the eighth of the image side. Both surfaces are concave surfaces, and the third lens has a concave surface, and the eleventh surface, which is a concave surface of the third lens and the fourth lens, is a convex surface, and the tenth surface of the object is a convex surface. The surface has a convex surface, and the object-side thirteenth surface and the image fourteenth surface of the fifth lens are both convex surfaces. The method of claim 4, wherein Both the catadioptric lens and the first lens have positive refractive power, the Abbe number of the catadioptric lens is 50 or more, the Abbe number of the first lens has an Abbe number of 25, and the fourth and fifth lenses. The omnidirectional optical system, wherein the lenses all have Abbe numbers greater than 50. The method according to any one of claims 1 to 8, The omnidirectional optical system can be applied to a high resolution camera with 2 Mega pixels on a 1 / 3-inch or 1 / 4-inch CCD, and the overall optical system length is reduced by 1/2 of the existing optical system length. An omnidirectional optical system characterized by having an optical system entered The method according to any one of claims 1 to 8, The optical system is an omnidirectional optical system having a contrast ratio of more than 40% at 100lp / mm in the MTF characteristic graph in the visible region A catadioptric lens support 210; A first reflection part disposed in the catadioptric lens supporter and formed on an inner side surface of the catadioptric lens supporter to be refracted by the incident light to be refracted, and to face the refracted incident light toward the center of the refracting part; 123, the second reflecting portion 124 formed on the inner surface of the refraction portion central portion and the light reflected from the second reflecting portion to transmit the incident light reflected through the first reflecting portion to the relay lens unit A catadioptric lens 110 including a transmission part 125; A relay lens unit (130) for condensing and imaging incident light refracted, reflected, and transmitted from the refracting part, the first reflecting part, the second reflecting part, and the transmitting part; A first housing 203 for supporting a catadioptric lens support 210 and the relay lens unit 130; A pentaprism 140 having a reflector formed on an inner surface thereof so as to reflect incident light passing through the relay lens unit in a right angle direction; A second housing 240 supporting the penta prism; Omni-directional camera, characterized in that it comprises a camera body 220 for receiving light from the penta prism The method of claim 11, The field angle of the catadioptric lens is 360 degrees, left and right, the omnidirectional camera, characterized in that 45 ~ 55 degrees The method of claim 11, The field angle of the catadioptric lens is 360 degrees left and right, up and down 53 degrees (up 37 degrees, 16 degrees lower) A refraction portion 313 in which incident light is refracted, a first reflection portion 323 formed on an inner side surface facing the refraction portion so as to reflect the refracted incident light toward the center portion of the refraction portion, and reflection through the first reflection portion A second reflection portion 324 formed on an inner surface of the central portion of the refracting portion, a diffuse reflection prevention step portion 326 formed adjacent to the first reflection portion 323, and the reflected light to reflect the incident light to the first relay lens unit; A catadioptric lens 310 including a transmission part 325 for transmitting the light reflected by the second reflection part; A first relay lens unit 330 for condensing and forming incident light refracted, reflected, and transmitted from the refracting part 313, the first reflecting part 323, the second reflecting part 324, and the transmitting part 325; ; A triprism 340 having an inclined surface reflector 341 formed to reflect the incident light passing through the first relay lens unit in a direction perpendicular to the second relay lens unit 350; It is installed at regular intervals in a direction perpendicular to the tri-prism, and the omni-directional optical system comprising a second relay lens unit 350 for collecting and imaging the incident light reflected from the tri-prism The method of claim 14, The field angle of the catadioptric lens is 360 degrees left and right, up and down 45-55 degrees The method of claim 14, The field angle of the catadioptric lens is 360 degrees left and right, up and down 52 degrees (upper 38 degrees, lower 14 degrees), characterized in that the omnidirectional optical system The method of claim 14, The first relay lens unit 330 may include a first lens 331 installed at the rear of the catadioptric lens 310 and a second lens 332 provided at a rear of the first lens 331 at predetermined intervals. And the second relay lens unit 350 includes a stop installed at regular intervals from the triprism 340 at right angles, a third lens 333 installed behind the stop, and The fourth lens 334 coupled to the third lens 333, the fifth lens 335 and the fifth lens 335 installed at a predetermined distance from the fourth lens 334 at a predetermined interval. The omnidirectional optical system comprising a sixth lens 336 is installed The method of claim 17, The catadioptric lens 110 converges a wide-angle light beam, and the first and second lenses emit light from the catadioptric lens 110, and the third lens, the fourth lens, and the third lens. The fifth lens and the sixth lens image the light emitted by the catadioptric lens, the first lens, the second lens, and the triprism to the sensor, thereby providing the catadioptric lens, the first lens, and the second lens, The third to sixth lenses have a positive-negative-negative (PNN) type refractive index, and a main surface (imaging surface, a reference surface for measuring Efl) exists inside the sixth lens, and Efl (effective focus). Distance) has a positive value, Bfl has a positive value, and Bfl has a structure of an inverse telephoto lens larger than the Efl value. Features omnidirectional optical system The method of claim 17, The first lens of the first relay lens unit has a fifth surface that is a convex surface of an object side and a sixth surface that is a convex surface of an image side. The second lens has a seventh surface that is a concave surface on the object side and an eighth surface that is an concave surface on the upper side, and the third lens of the second relay lens unit is a plane on the object side. Surface, the twelfth surface which is the combined surface of the third lens and the fourth lens, the fourth lens is the thirteenth surface which is the convex surface of the image, and the fifth lens is the fourteenth surface which is the convex surface of the object, and the convex surface of the image. Has a sixteenth surface, and the sixth lens has a sixteenth surface that is a convex surface on the object side and a seventeenth surface that is a convex surface on the image side. The method of claim 17, Both the catadioptric lens and the first lens have positive refractive power, the Abbe number is 50 or more, the second lens and the third lens have an Abbe number of 20 to 25, and the fourth to sixth lenses All-round optical system characterized by having more than 50 Abbe number The method according to any one of claims 14 to 20, The omnidirectional optical system can be applied to a high resolution camera with 2 Mega pixels on a 1 / 3-inch or 1 / 4-inch CCD, and the overall optical system length is reduced by 1/2 of the existing optical system length. An omnidirectional optical system characterized by having an optical system entered The method according to any one of claims 14 to 20, The optical system is an omnidirectional optical system having a contrast ratio of more than 40% at 160 lp / mm in the MTF characteristic graph in the visible region A catadioptric lens support 210; A refraction portion 313 disposed inside the catadioptric lens support and formed on an inner side surface of the catadioptric lens support opposite to the refraction portion so as to reflect the refracted incident light toward the center portion of the refraction portion; 323, adjacent to the first reflecting portion 323, the second reflecting portion 324 formed on the inner surface of the refraction portion center portion so as to reflect incident light reflected through the first reflecting portion to the first relay lens unit; A catadioptric lens 310 including a diffuse reflection prevention step portion 326 and a transmission portion 325 for transmitting the light reflected by the second reflection portion; A first relay lens unit 330 for condensing and forming incident light refracted, reflected, and transmitted from the refracting part 313, the first reflecting part 323, the second reflecting part 324, and the transmitting part 325; ; A first housing 203 for supporting the catadioptric lens support and the first relay lens unit; A triprism 340 having an inclined surface reflector 341 formed to reflect the incident light passing through the first relay lens unit in a direction perpendicular to the second relay lens unit 350; A second relay lens unit (350) installed at regular intervals in a direction perpendicular to the triprism, for collecting and imaging the incident light reflected from the triprism; A second housing 240 supporting the triprism and the second relay lens unit; The omnidirectional camera, comprising a camera body 220 for receiving light from the second relay lens unit The method of claim 23, wherein The field angle of the catadioptric lens is 360 degrees, left and right, the omnidirectional camera, characterized in that 45 ~ 55 degrees The method of claim 23, wherein The field angle of the catadioptric lens is 360 degrees left and right, up and down 52 degrees (upper 38 degrees, lower 14 degrees), characterized in that the omnidirectional camera

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