JP2019049739A - Imaging device - Google Patents

Abstract

To achieve a new imaging device that uses two wide angle lenses having a total angle of view of larger than 180 degrees.SOLUTION: An imaging device of the present invention is an imaging device that combines two imaging optical systems comprising an image forming optical system having a total angle of view of larger than 180 degrees and a two-dimensional solid state imaging element converting an image formed by the image forming optical system into an image signal to pick up an omnidirectional image. The two imaging optical systems have the same structures and each have first lens groups L1I, L2I arranged on an object side, second lens groups L1II, L2II arranged on an image side of the first lens groups, and a reflection surface member PC; the reflection surface member PC has a first reflection surface RF that bends the optical axes of the first lens groups in a first direction, and a second reflection surface that bends the optical axis of the light beam reflected on the first reflection surface in a second direction intersecting common planes including the optical axes of the first lens groups and the first direction; the two imaging optical systems are combined such that the optical axes of the first lens groups match each other, both the common planes are in the same plane, and the second directions are on the same side of the same plane.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an imaging device.

  An imaging device for imaging an “omnidirectional image” corresponding to 4π radian in solid angle at one time is conventionally known from Patent Documents 1 and 2.

  As an image pickup apparatus for "picking up an image at once", it is known to use two "wide-angle lenses (so-called" fish-eye lenses ") having a total angle of view exceeding 180 degrees" (Patent Documents 1 and 2) .

  Such an imaging device can simultaneously acquire omnidirectional image information, and thus can be effectively used, for example, as a surveillance camera for crime prevention or an on-vehicle camera.

  In addition, recently, application to endoscopes for industrial use and medical use is also intended.

  The wide-angle lens tends to increase the number of constituent lenses to secure performance as the total angle of view increases, and the wide-angle lens having a large total angle of view tends to increase the total lens length.

  When two such wide-angle lenses having a large overall lens length are combined, the size of the imaging device itself tends to be large.

  In consideration of such "size enlargement", there has been proposed one that uses the optical axis of a wide-angle lens by bending it with a reflecting surface (Patent Document 3).

  An object of the present invention is to realize a novel imaging device using two wide-angle lenses having a full angle of view exceeding 180 degrees.

  An imaging apparatus according to the present invention comprises an imaging optical system having a total angle of view larger than 180 degrees, and a two-dimensional solid-state imaging device for converting an image formed by the imaging optical system into an image signal. An imaging apparatus for imaging an omnidirectional image by combining two optical systems, wherein the two imaging optical systems have the same structure, and a first lens group disposed on the object side, and the first lens A second lens group disposed on the image side of the group, and a reflective surface member, the reflective surface member being a first reflective surface that bends the optical axis of the first lens group in a first direction; A second reflection surface for bending an optical axis of the light beam reflected by the first reflection surface in a second direction intersecting a common plane including the optical axis of the first lens group and the first direction; In the two imaging optical systems, the optical axes of the first lens group coincide with each other, and the common planes are in the same plane, One, combined such that the second direction each other the same side of the same plane.

  According to the present invention, it is possible to realize a novel imaging device using two wide-angle lenses having a full angle of view exceeding 180 degrees.

It is a figure for demonstrating one Embodiment of an imaging device. FIG. 2 is a ray diagram in the embodiment of FIG. 1; It is a figure for demonstrating another form of implementation of an imaging device. FIG. 4 is a ray diagram in the embodiment of FIG. 3; It is a figure for demonstrating one Embodiment which provided the illumination means.

Hereinafter, embodiments will be described.
FIG. 1 is a conceptual diagram for explaining an embodiment of an imaging device.

  The imaging device whose embodiment is shown in FIG. 1 has two imaging optical systems.

  Hereinafter, these two imaging optical systems are referred to as a first imaging optical system and a second imaging optical system.

  (A-1) and (a-2) of FIG. 1 are diagrams for explaining the first imaging optical system, and (b-1) and (b-2) are for explaining the second imaging optical system. It is a figure for.

  The “first imaging optical system” will be described with reference to FIGS. 1 (a-1) and 1 (a-2).

In FIG. 1 (a-1) and (a-2), the code | symbol L1I shows a "1st lens group." Further, a code L1II indicates a "second lens group".
The symbol IS1 indicates "solid-state imaging device (hereinafter, referred to as first imaging device IS1)".

Furthermore, code | symbol PC shows a "reflective surface member."
The left side of the figure in FIG. 1 (a-1) is the object side.

  The first lens unit L1I is a lens unit disposed on the object side and has "negative refracting power", and in this example, is constituted by two lenses L11 and L12.

  The second lens unit L1II is a lens unit disposed on the image side of the first lens unit L1I, and has “positive refractive power”, and is configured of five lenses L13, L14, L15, L16, and L17.

  Specifically, the lenses L11 and L12 of the first lens unit L1I are both "negative meniscus lenses made of glass material".

  The lenses L13 and L14 of the second lens unit L1II are both “biconvex lenses of glass material”, and the lens L15 is “biconvex lenses of glass material”.

  The lens L16 is a “biconcave lens of glass material” and is joined to the lens L15.

  The lens L17 disposed closest to the image side is a "biconvex lens of glass material".

  The second imaging optical system will be described with reference to FIGS. 1 (b-1) and 1 (b-2).

  In FIG. 1 (b-1) and (b-2), the code | symbol L2I shows a "1st lens group." Further, a symbol L2II indicates a "second lens group".

  The symbol IS2 indicates "solid-state image sensor (hereinafter, referred to as second image sensor IS2)".

Furthermore, code | symbol PC shows a "reflective surface member."
In FIG. 1 (b-2), the right side of the figure is the object side.

  The first lens unit L2I is a lens unit disposed on the object side and has "negative refracting power", and in this example, is constituted by two lenses L21 and L22.

  The second lens unit L2II is a lens unit disposed on the image side of the first lens unit L2I, having “positive refractive power”, and is configured of five lenses L23, L24, L25, L26, and L27. .

  Specifically, the lenses L21 and L22 of the second lens unit L2I are both "negative meniscus lenses made of glass material".

  The lenses L23 and L24 of the second lens unit L2II are both “biconvex lenses of glass material”, and the lens L25 is “biconvex lenses of glass material”.

  The lens L26 is a "biconcave lens of glass material" and is joined to the lens L25.

  The lens L27 disposed closest to the image side is a "biconvex lens of glass material".

FIG. 1 (a-2) is the figure which looked at the state of the figure (a-1) from "the right side of a figure."
Further, (b-1) is a view of the state of (b-2) as viewed from the "right side of the figure".

  FIGS. 1 (c-1), (c-2), and (c-3) are diagrams for explaining a state in which the first imaging optical system and the second imaging optical system are combined.

  FIG. 1C-1 is a state in which the state in which the first and second imaging optical systems are combined is viewed from the direction orthogonal to the drawings of (a-1) and (b-2).

  The second lens units L1II and L2II overlap each other in the direction orthogonal to the drawing. Similarly, the first imaging device IS1 and the second imaging device IS2 also overlap each other in the direction orthogonal to the drawing.

  FIG. 1C-2 is a state in which the state in which the first and second imaging optical systems are combined is viewed from the direction orthogonal to the drawings of (a-2) and (b-1).

  FIG. 1C-3 is a state in which "a state in which the first and second imaging optical systems are combined" is viewed from the upper side of the diagrams (a-1) to (b-2).

  Next, the reflecting surface member PC used in the embodiment of FIG. 1 will be described.

  In the embodiment of FIG. 1, the first imaging optical system and the second imaging optical system share the reflective surface member PC.

  That is, the reflective surface member PC is a “component of the first imaging optical system” and is also a “component of the second imaging optical system”.

  The reflective surface member PC is composed of three parts as shown in FIG. 1 (a-2) and the like. These three parts are a cubic prism P0 and triangular prisms P1 and P2.

  As shown in FIG. 1 (c-3), the prism P0 is formed by bonding two triangular prisms at an inclined surface, and the bonding surface RF is a reflection surface.

  As shown in FIG. 1C, the imaging light flux incident from the first lens group L1I of the first imaging optical system is reflected toward the triangular prism P1 by the cemented surface RF of the prism P0.

  That is, the cemented surface RF of the prism P0 bends the optical axis of the first lens group L1I toward the side of the triangular prism P1 which is the first direction. The angle of bending is 90 degrees.

  Similarly, the imaging light flux incident from the first lens group L2I of the second imaging optical system is reflected to the side of the triangular prism P2 by the cemented surface RF of the prism P0.

  That is, the cemented surface RF of the prism P0 bends the optical axis of the first lens unit L2I toward the side of the triangular prism P2 which is the second direction. The angle of bending is 90 degrees.

  Therefore, the “junction surface RF” of the prism P0 is a first reflection surface of the first imaging optical system and a first reflection surface of the second imaging optical system.

  Hereinafter, the bonding surface RF is also referred to as a first reflection surface RF.

  The imaging light flux incident from the first lens group L1I is reflected to the trigonal prism P1 side by the first reflection surface, is reflected again by the slope, and is incident on the second lens group L1II.

  At this time, the optical axis of the first lens group L1I is bent 90 degrees toward the direction of the second lens group L1II which is the “second direction”, and coincides with the optical axis of the second lens group L1II.

  That is, the slope of the triangular prism P1 is the "second reflecting surface" of the first imaging optical system.

  The imaging light flux incident on the second lens unit L1II is a two-dimensional image (hereinafter referred to as a “first two-dimensional image”) on the light receiving surface of the first imaging element IS1 by the imaging action of the first lens unit L1I and the second lens unit L1II. Say).

  The same applies to the second imaging optical system.

  That is, the imaging light flux that has entered the prism P0 from the first lens group L2I is reflected by the first reflection surface RF toward the triangular prism P2.

  Then, the light is reflected again by the inclined surface of the triangular prism P2 and is incident on the second lens unit L2II.

  At this time, the optical axis of the first lens unit L2I is bent by 90 degrees toward the direction of the second lens unit L2II which is the “second direction”, and coincides with the optical axis of the second lens unit L2II.

  That is, the slope of the triangular prism P2 is the "second reflection surface" of the second imaging optical system.

  The imaging light flux incident on the second lens unit L2II is a two-dimensional image (hereinafter referred to as a “second two-dimensional image”) on the light receiving surface of the second imaging element IS2 by the imaging action of the first lens unit L2I and the second lens unit L2II. Say).

  Each of the first imaging element IS1 and the second imaging element IS2 has a "two-dimensional light receiving surface", picks up a two-dimensional image formed on the light receiving surface, and converts it into an electric signal.

  The “first two-dimensional image” captured by the first imaging element IS1 and the “second two-dimensional image” captured by the second imaging element IS2 respectively have the same image information in the peripheral portion.

  That is, since the first imaging optical system and the second imaging optical system are configured by the imaging optical system having a total angle of view larger than 180 degrees, the overlapping area exists in the image information imaged by the respective imaging elements. There is.

  Therefore, the same image information (image information of the overlapping area) is detected as a “connection position”, distortion correction is performed by electrical information processing, and then expanded on a plane, and then one image is obtained by “blend processing”. Tie them together.

  In this way, an "omnidirectional image" can be obtained.

  As described above, the image pickup apparatus shown in the embodiment in FIG. 1 has a “image forming optical system having a total angle of view larger than 180 degrees and a two-dimensional image forming an image formed by the image forming optical system. This is an imaging device that captures an omnidirectional image by combining two imaging optical systems configured with a solid-state imaging device.

  The two imaging optical systems have the same structure, and respectively include first lens groups L1I and L2I disposed on the object side, and second lens groups L1II and L2II disposed on the image side of the first lens group, And a reflective surface member PC.

  The reflective surface member PC has a first reflective surface RF and a second reflective surface.

  The “first reflection surface” is a reflection surface that “bent in the first direction” the optical axis of the first lens unit L1I, L2I, and is a “junction surface RF of the prism P0”.

  The “second reflective surface” is a plane of the common plane including the optical axis of the first lens group and the first direction (FIG. 1 (c-3), “the optical axis of the light beam reflected by the first reflective surface RF. The reflection surface is bent in a second direction (a plane perpendicular to the drawing of FIG. 1 (c-3)) that intersects “a plane parallel to the plane”.

  The “second reflection surface” is an inclined surface of the triangular prism P1 in the first imaging optical system, and an inclined surface of the triangular prism P2 in the second imaging optical system.

  In the two imaging optical systems, the optical axes of the first lens units L1I and L2I coincide with each other, and the common planes are "in the same plane (the plane shown in (c-3) in FIG. 1)" .

  The “second directions” are combined so as to be on the same side of the same plane.

  Also in the embodiment of FIG. 1, the reflecting surface member PC of each imaging optical system is a prism having a first reflecting surface RF and a second reflecting surface (slopes of the triangular prisms P1 and P2).

  The first direction is orthogonal to the optical axis of the first lens group L1I, L2I, and the second direction is orthogonal to the first direction.

  The two imaging optical systems share the reflective surface member PC.

FIG. 2 shows a ray diagram of the embodiment described above.
FIG. 2 (a) is the same as FIG. 1 (c-3).

  FIG.2 (b) has shown the ray diagram in the state of FIG.1 (c-1).

  FIG.2 (c) has shown the ray diagram in the state of FIG.1 (c-2).

  FIG. 3 is a diagram schematically illustrating another embodiment of the imaging device.

  In order to avoid complication, those which are considered to have no risk of confusion are given the same reference numerals as in FIG.

  The image pickup apparatus described in the embodiment with reference to FIG. 1 can pick up an image in all directions corresponding to 4π radian at a solid angle at one time. The “optical system of an imaging device capable of capturing an omnidirectional image” is referred to as a “large-field optical system” for the sake of convenience.

  The imaging device of the embodiment shown in FIG. 3 is obtained by adding a “small field optical system” to the “imaging device having a large field optical system” shown in FIG.

  In FIG. 3A, the “small-field optical system” is indicated by the code SKIII.

  FIG. 3B shows a portion obtained by removing the second lens unit L2II of the second imaging optical system from the state of FIG. 3A for the sake of simplicity of the drawing.

  As shown in FIG. 3B, the small-field optical system includes a first lens unit L3I, a second lens unit L3II, and a third imaging element IS3.

  The first lens group L3I is a single negative lens (negative meniscus lens), and the second lens group L3II is composed of five lenses and has positive refractive power.

The third imaging element IS3 is a solid-state imaging element having a two-dimensional light receiving surface.
The first lens unit L3I and the second lens unit L3II constitute an "imaging lens system for a small field of view". The third imaging element IS3 is a "small-field solid-state imaging element".

  The first lens unit L3I and the second lens unit L3II "share the optical axis".

  FIG. 3 (c) shows the state shown in FIG. 3 (a) as viewed from the top of the figure.

  In the first lens group L3I, the optical axis AX is a plane perpendicular to the common plane of the two imaging optical systems (FIG. 3A in the vertical direction of FIG. 3C, and a plane parallel to the FIG. Approximately orthogonal to the same plane in which the

  Therefore, the optical axis of the second lens group L3II is parallel to the optical axes of the second lens group L1II, L2II of the first imaging optical system and the second imaging optical system.

  As shown in FIG. 3C, the prism P0 of the reflecting surface member PC is formed by bonding two triangular prisms P01 and P02 at a bonding surface RF, and the bonding surface RF forms a "first reflection surface".

  The optical axis AX of the imaging lens system for the small field of view is set to pass through the inside of the prism P02 which is one of the two triangular prisms constituting the prism P0.

  Then, the imaging lens system for small field of view is configured such that the imaging light flux passing through the inside of the lens transmits only the inside of the prism P02 and "does not intersect the first reflection surface RF".

  Therefore, the “imaging light flux for a small field of view” formed on the third imaging element IS3 is not subjected to the reflection action of the first reflection surface RF.

  That is, in the imaging apparatus of the embodiment shown in FIG. 3, the imaging lens systems L3I and L3II for the small field of view having the optical axis AX substantially orthogonal to the same plane including the common plane of the two imaging optical systems It has a small-field solid-state imaging device IS3 for capturing an image by the imaging lenses L3I and L3II via a shared plane.

  FIG. 4 shows a ray diagram in the embodiment of FIG.

  FIG. 4 is a ray diagram in the state shown in FIG.

  FIG. 4 also shows ray diagrams of the second lens group L1II and L2II in the first and second imaging optical systems, as well as rays of light below the second lens group of the small-field imaging lens system.

  Supplementally, the imaging optical system whose embodiment is shown in FIG. 1 and FIG. 3 can be used, for example, as a “head portion” of an industrial or medical endoscope.

  As a specific example, it is assumed that the imaging device of FIGS. 1 and 3 is used as the head portion of the “medical endoscope”.

  The imaging device shown in FIG. 1 and FIG. 3 can be realized to be about 12 mm as the size in the left and right direction in FIG. 1 (c-1) and FIG. 3 (a).

  Therefore, for example, when observing the inner wall of the esophagus or stomach of a human body, the imaging device of FIGS. 1 and 3 is configured as the “head portion of a flexible endoscope” and is orally inserted from the head portion side for observation it can.

  At this time, since it is possible to acquire an “all direction” image with respect to the head portion, extremely efficient and accurate observation is possible.

  Alternatively, when using the imaging device of FIGS. 1 and 3 as the head portion of the “hard endoscope”, for example, when performing a surgery on the stomach, the surgeon can “read all directions including the portion to be operated” Can be observed without

  When performing such an operation, it may be desired to observe an “image of high resolution and high magnification” for “necessary part such as a resected part” as well as an omnidirectional image.

  In such a case, for example, in the case of using the image pickup apparatus of FIG. 1, “necessary area” of the omnidirectional image can be designated, and this part can be enlarged by “digital image processing”.

  However, in this case, since the “pixel information included in the image to be enlarged” does not change, the enlarged image does not have high resolution.

  In such a case, it is possible to display the light reception image of the third imaging element IS3 using the imaging device of FIG. 3 and using the aforementioned “small-field optical system” as necessary.

  The small-field optical system does not have to have a large field of view, the imaging magnification can be set large, and a high-resolution, high-magnification image of the necessary part can be observed from the light reception image of the third imaging element IS3.

  In this case, the imaging device of FIG. 3 is provided at the distal end portion of the rigid endoscope, and the optical axis of the small-field optical system coincides with the longitudinal direction of the “operating rod of the rigid endoscope”.

  Therefore, the first lens unit L3I of the imaging lens system in the small-field optical system can be easily directed to a desired portion.

  By the way, assuming that the imaging device shown in FIGS. 1 and 3 is used as an industrial or medical endoscope, in this case, the “observation site” is generally dark.

  Therefore, in such a case, an illumination means for illuminating the observation site is required.

  In view of the fact that the imaging device can acquire an "omnidirectional image", the illumination means in this case is only in front of the device (the upper part of the figure in FIG. In addition, it is necessary to be able to illuminate the periphery of the side of the device.

  In consideration of the size and application of the imaging device, it is preferable to use a plurality of white LEDs as the illumination means. In the case of illuminating the entire circumference of the imaging device, it is preferable to use seven or more LEDs.

  When illuminating the front of the device and the side circumference, it is preferable to use five white LEDs.

  That is, at least five white LEDs may be provided as illumination means in a housing that accommodates two imaging optical systems or two imaging optical systems and a small-field optical system.

  Three of the five LEDs are disposed between the first lens group of the first imaging optical system and the first lens group of the second imaging optical system.

  The other two LEDs are arranged at positions on both sides in a plane orthogonal direction of a plane including the optical axes of the first imaging optical system and the second lens group of the second imaging optical system.

  Then, the front and the side are illuminated by these five LEDs.

  FIG. 5 shows an example of an embodiment in which five “white LEDs” are provided in the image pickup apparatus whose embodiment is shown in FIG.

In FIG. 5, reference numerals 11 to 15 indicate first to fifth white LEDs.
Further, in FIG. 5, reference symbol HS indicates a "housing" of the imaging device.

  In FIG. 5 (a), the part excluding the housing HS and the LEDs 11, 12, 14, 15 is the same as that shown in FIG. 1 (c-1).

  Moreover, in FIG.5 (b), the part except the housing HS and LED11,12,13,14 is the same as what is shown in FIG.1 (c-1).

  In order to avoid complication of the drawings, in FIGS. 5 (a) and 5 (b), symbols are omitted for the same parts as those in FIGS. 1 (c-1) and 1 (c-2).

  In this example, the housing HS is formed of “a material that is entirely transparent” such as transparent plastic, and accommodates the two imaging optical systems in the imaging device, but the first lens of the first and second imaging optical systems The lens surface of the most object-side lens in the group is exposed outside the housing.

  The LEDs 11, 12, 13 are disposed between the first lens group of the first imaging optical system and the first lens group of the second imaging optical system.

And LED11 illuminates the front (upper part of Drawing 5) field of an imaging device, and LED12 and 13 illuminate "a front field and the side field on either side".
In addition, the LEDs 14 and 15 illuminate the side area in the rear part of the imaging device.

In this way, the front and side areas of the imaging device are illuminated.
The white LED generally has a "Lambert distribution" of the angular distribution of light emission and a very large divergence angle, so that the "rear region of the imaging device" is also illuminated by the LEDs 14 and 15.

  In order to more effectively illuminate the rear area of the imaging device, for example, two more LEDs may be added so that the illumination area effectively extends to the rear area.

  When the image pickup apparatus has the “small field optical system” in addition to the first and second image pickup optical systems, the LED 11 may be disposed avoiding the first lens group L3I of the small field optical system.

  Needless to say, the role of the "lighting means" is to illuminate the imaging target by the imaging device, but it also has the following role.

  Consider the case where the imaging device of the embodiment of FIG. 5 is used as, for example, a “medical endoscope”.

In this case, the inside of the living body into which the endoscope is inserted is in a "humidity: 100% state".
As described above, the lens surface of the most object-side lens in the first lens group of the first and second imaging optical systems is exposed outside the housing, so the lens surface becomes cloudy in use.

  In the embodiment of FIG. 5, the heat of the LEDs 11, 12, 13 is transmitted to the above-mentioned "lens whose lens surface is exposed to the outside", and the heat can prevent "clouding of the lens surface".

  As described above, according to the present invention, the following imaging apparatus can be realized.

[1]
Two imaging optical systems comprising an imaging optical system having a total angle of view greater than 180 degrees and a two-dimensional solid-state imaging device for converting an image formed by the imaging optical system into an image signal An imaging apparatus for imaging an omnidirectional image, wherein two imaging optical systems have the same structure, and each includes a first lens group L1I, L2I disposed on the object side, and an image side of the first lens group A second reflective lens group L1II, L2II, and a reflective surface member PC, the reflective surface material PC bending the optical axis of the first lens group in a first direction; RF, and a second reflection surface that bends the optical axis of the light beam reflected by the first reflection surface in a second direction intersecting a common plane including the optical axis of the first lens group and the first direction The optical axes of the first lens group coincide with each other, and the two imaging optical systems Each other are in the same plane, and the imaging device in which the second direction each other are combined so that the same side of the same plane.

[2]
In [1], the reflecting surface member PC of each imaging optical system is a prism having a first reflecting surface and a second reflecting surface, and the first direction is the optical axis of the first lens group L1I, L2I An imaging device which is orthogonal and whose second direction is orthogonal to the first direction.

[3]
[2] The imaging device according to [2], wherein the two imaging optical systems share a reflective surface member PC.

[4]
In the imaging device according to [1], [2] or [3], an imaging lens system L3I, L3II for a small field of view having an optical axis substantially orthogonal to the same plane including common planes of two imaging optical systems An image pickup apparatus having a small-field solid-state imaging device IS3 for picking up an image by the imaging lens systems L3I and L3II through the common plane as a small-field optical system.

[5]
In the imaging apparatus according to [4], the reflecting surface member PC is a prism having a first reflecting surface and a second reflecting surface, the first direction being orthogonal to the optical axis of the first lens group, and Direction is orthogonal to the first direction and shared by the first imaging optical system and the second imaging optical system, and the first reflecting surface RF of the reflecting surface member is a junction of the triangular prisms P01 and P02. The optical axis AX of the imaging lens system for a small field of view is formed as a surface, and passes through only one of the triangular prisms P02, and an imaging light beam by the imaging lens system for a small field of view Imaging devices that do not intersect.

[6]
In the image pickup apparatus according to any one of [1] to [5], at least five white colors are provided in a housing that accommodates two image pickup optical systems or two image pickup optical systems and a small-field optical system. LEDs 11 to 15 are provided as illumination means, and three of the five LEDs are disposed between the first lens group of the first imaging optical system and the first lens group of the second imaging optical system, The two LEDs are arranged at positions on both sides in a plane orthogonal direction of the plane including the optical axis of the first lens system and the second lens group of the second camera optical system, and these five LEDs An imaging device that illuminates people.

  In the above embodiment, the “imaging lens system” in the first and second imaging optical systems used has a focal length f, an angle of view θ, and an image height y A so-called "equidistant projection method" in which = f · θ is adopted.

  In the equidistant projection method, “image height distance from the center of the image to the periphery: y is proportional to the incident angle: θ”, and it is possible to use many pixels around the two-dimensional light receiving surface in the solid-state imaging device It can.

  For this reason, if the optical performance (MTF) resolves "substantially uniform to the periphery", it is possible to acquire a uniform image over the entire screen.

  In the imaging device of the present invention, the two solid state imaging devices IS1 and IS2 that receive the images of the two imaging optical systems can be arranged on the same side with respect to the reflecting surface member PC.

  Therefore, the assembly of the solid-state imaging device is easy, and the flexible wiring can be easily routed.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments described above, and the invention described in the appended claims unless otherwise limited in the above description. Various modifications and changes are possible within the scope of the present invention.
For example, in the embodiment described above, the bending of the optical axis in the first direction by the first reflecting surface and the bending of the optical axis by the second reflecting surface are 90 degrees, but the angle of bending is limited to this. Absent.

  In addition, although the case where the triangular prism P1 and P2 are joined to the prism P0 as a reflecting surface member is shown, the present invention is not limited to this, the portion of the triangular prism P01 of the prism P0 and the portion of the triangular prism P1 Good.

  Similarly, the portion of the triangular prism P02 of the prism P0 and the portion of the triangular prism P2 may be integrally formed.

  The effects described in the embodiments of the present invention merely list the preferable effects resulting from the invention, and the effects of the invention are not limited to those described in the embodiments.

L1I First lens group of the first imaging optical system
L2I First lens group of second imaging optical system
L1II Second lens group of the first imaging optical system
L2II Second lens group of second imaging optical system
PC reflective surface member
RF first reflective surface
P1 Triangular Prism
P2 triangular prism
IS1 Solid-state imaging device of first imaging optical system
IS2 Solid-state imaging device of second imaging optical system

Unexamined-Japanese-Patent No. 2010-271675 Patent No. 3290993 JP, 2014-56048, A

Claims (6)

Two imaging optical systems comprising an imaging optical system having a total angle of view greater than 180 degrees and a two-dimensional solid-state imaging device for converting an image formed by the imaging optical system into an image signal An imaging apparatus for capturing an omnidirectional image,
The two imaging optical systems have the same structure, and each includes a first lens group disposed on the object side, a second lens group disposed on the image side of the first lens group, and a reflecting surface member. Have
The reflective surface member includes a first reflective surface that bends an optical axis of the first lens group in a first direction, and an optical axis of a light beam reflected by the first reflective surface as light of the first lens group. A second reflective surface bent in a second direction intersecting a common plane including the axis and the first direction;
The two imaging optical systems are combined such that the optical axes of the first lens group coincide with each other, the common planes are in the same plane, and the second directions are on the same side of the same plane. Imaging device. In the imaging device according to claim 1,
The reflecting surface member of each imaging optical system is a prism having a first reflecting surface and a second reflecting surface, the first direction being orthogonal to the optical axis of the first lens group, and the second direction being the above An imaging device orthogonal to the first direction. In the imaging device according to claim 2,
An imaging apparatus in which two imaging optical systems share a reflective surface member. In the imaging device according to claim 1 or 2 or 3,
An imaging lens system for a small field of view having an optical axis substantially orthogonal to the same plane including common planes of two imaging optical systems, and a solid for small field of view imaging an image by the imaging lens through the common plane An imaging device having an imaging element as a small-field optical system. In the imaging device according to claim 4,
The reflecting surface member is a prism having a first reflecting surface and a second reflecting surface, the first direction being orthogonal to the optical axis of the first lens group, and the second direction being orthogonal to the first direction. Shared by the first imaging optical system and the second imaging optical system,
The first reflective surface of the reflective surface member is formed as a junction surface of a triangular prism,
An imaging device in which an optical axis of an imaging lens system for a small field of view passes through only one of the triangular prisms, and an imaging light beam by the imaging lens system for a small field of view does not intersect with the cemented surface. The imaging device according to any one of claims 1 to 5.
At least five white LEDs are provided as illumination means in a housing that accommodates two imaging optical systems or two imaging optical systems and a small-field optical system,
Three of the five LEDs are disposed between the first lens group of the first imaging optical system and the first lens group of the second imaging optical system,
The other two LEDs are arranged at positions on both sides in a plane orthogonal direction of a plane including the optical axes of the first imaging optical system and the second lens group of the second imaging optical system,
An imaging device that illuminates the front and the side with these five LEDs.

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