JP2005333617A - Thin imaging device, thin camera using the same, and imaging method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin imaging device which is of extremely small height, excellent in resolution, and capable of acquiring image information of high quality. <P>SOLUTION: The imaging device is equipped with a light guide path, an incidence mirror (2), an imaging element, and an aperture. In the thin imaging device, the incidence mirror (2) reflects light emitted from an object (4) so as to guide it to the light guide path, and the imaging element receives light, emitted from the object (4) and reflected by the incidence mirror (2) so as to pass through the light guide path, so as to image the object (4). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an imaging apparatus typified by a digital camera module, and more particularly to a thin imaging apparatus having an improved configuration corresponding to an application requiring extremely thin thickness such as a portable information terminal.

  In recent years, the downsizing and high performance of image sensors such as CCD and CMOS sensors, and the advancement of optical technology such as aspherical lenses have made it possible to reduce the size of image pickup devices, such as compact digital cameras and camera phones. Applications of imaging devices are expanding to applications where the camera can be easily carried. Camera modules used in these portable devices are required to be further reduced in size and height in consideration of various situations.

  An imaging device used in a conventional camera module has a configuration in which a circular condensing lens and a CCD or CMOS sensor are arranged on its imaging surface to perform imaging. (For example, refer to Patent Document 1 (pages 2 to 4, FIG. 1, Table 1, etc.)). FIG. 14 shows a conventional imaging device described in Patent Document 1.

  In the example of FIG. 14, a lens composed of two groups 101 a and 101 b is used as the condensing lens system 101, and incident light collected by the lens passes through the glass filter 102 and is on the surface of the image sensor 103. Is imaged. Here, FIG. 14 shows a cross-sectional view, and the condensing lens system 101 has a concentric shape with the optical axis represented by the alternate long and short dash line as the rotation center. In this example, the zoom and focus functions are realized by changing the positions of both the two groups of condensing lenses 101a and 101b. Reference numeral 104 denotes an aperture stop for changing the effective aperture ratio of the lens system.

  In a conventional imaging apparatus, when trying to obtain a beautiful image in focus, it is necessary to dispose the imaging element 103 on the surface on which the subject image is formed by the condenser lens system 101, and the focus of the condenser lens system 101. The distance determines the distance between the condenser lens system 101 and the imaging surface of the image sensor 103. Therefore, in the conventional image pickup apparatus, the focal length of the condenser lens system 101 is designed to be short, the distance from the image pickup element 103 is shortened, the entire length of the optical system is shortened, and the size and height are reduced. .

  Incidentally, taking Table 1 of Patent Document 1 as an example, the focal length is variable between 2.46 and 4.74 mm, and zooming is possible, but the total length of the lens system is 12.91 to 10.79 mm. And an optical system that is considerably longer than the effective focal length. This also shows that it is necessary to shorten the focal length more than expected in order to shorten the overall length of the optical system and reduce the height.

Further, as in the optical system disclosed in Patent Document 2, there is also a technical idea that aims to realize a low profile by combining a plurality of prisms to fold an optical path.
JP 2003-255225 A JP 2002-196243 A

  In the configuration of Patent Document 1, since the focal length of the lens is shortened to reduce the size and the height, the size of the image to be formed is also reduced in proportion to the focal length, and imaging with the same pixel pitch as the conventional one is performed. When the element is used, the resolution is relatively deteriorated with respect to the formed image. Therefore, in order to obtain image information with the same resolution as before, it is necessary to reduce the pixel pitch of the image sensor in proportion to the reduction in the focal length of the lens.

  CCD and CMOS sensors used as image sensors are already manufactured using the most advanced fine semiconductor processes. However, a finer manufacturing process is required to reduce the pitch, and the process cost is reduced by making the structure finer. In addition, there is a problem that an increase in cost is unavoidable because the yield is extremely deteriorated.

  In addition, by reducing the pixel pitch of the image sensor, the light receiving area of each pixel is reduced by the square of the pitch reduction rate. Further, each pixel of the image sensor has a driving matrix wiring, a charge transfer path in a CCD, etc. The area other than the light receiving area is also necessary, and the effective aperture ratio that can be received by reducing the pixel pitch also decreases, so the amount of received light is extremely reduced and it is difficult to obtain sufficient photoelectric conversion capability, and the image quality is remarkably improved. It has a problem of deterioration.

  Furthermore, the wavelength range of visible light is about 200 nm to 800 nm, and because of the diffraction limit, it is impossible to obtain a resolution of an image at a wavelength level with an optical system such as a lens. Even if an image sensor with a fine pixel pitch is created at the expense of yield, cost, and photoelectric conversion capability, the focal length of the lens can be reduced while maintaining high resolution due to the light diffraction limit.・ There is a problem that there is a limit to reducing the height.

  As described above, the conventional imaging device requires an optical system having a full length longer than the required focal length, and it is further difficult to reduce the size and height of the imaging device.

  In other words, there is a limit to shortening the focal length of the lens by reducing the focal length of the lens in the conventional configuration, and it is difficult to reduce the distance between the lens and the image sensor depending on the focal length of the lens, It is extremely difficult to reduce the height.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a thin imaging device capable of obtaining high-quality image information having an extremely low height and excellent resolution.

  In the first aspect, the present invention provides an opening, an incident mirror that simultaneously reflects incident light incident from the subject through the opening, a light guide that guides the incident light reflected by the incident mirror, and a light guide A mirror surface provided on at least a part of the surface, at least a first section that is a part of the object guided in the light guide path without being reflected by the mirror surface, and reflected by the mirror surface at least once and guided. An image sensor that simultaneously receives light in a state of being superimposed on a second section that is another part of the subject guided in the optical path.

  According to a second aspect of the present invention, in the second aspect, a predetermined processing is performed on image information from the thin imaging device described in the first aspect, an operation unit that can input an operator's imaging execution instruction, and the thin imaging device. And a controller that controls the storage unit, an image processing unit that executes image processing to generate image data, a storage unit that stores image data, a thin imaging device, an image processing unit, and a storage unit .

  In a third aspect, the present invention is a camera configured by incorporating the thin imaging device according to the first aspect in a card-type case.

  According to the fourth aspect of the present invention, in the fourth aspect, the first section, which is a part of the incident light from the subject, is guided in the light guide and is directly captured without being reflected by the mirror surface formed on the surface of the light guide. The step of entering the element and the second section, which is another part of the incident light from the subject, are guided in the light guide and reflected at least once by the mirror surface formed on the surface of the light guide to the image sensor. The imaging method includes an incident step and a step of superimposing at least a first section image and a second section image from the image sensor and simultaneously outputting them.

  With the thin imaging device of the present invention, the thickness of the optical system can be at most as low as the thickness of the light guide, and the optical path length from the incident mirror to the image sensor through the light guide is Since it can be taken for a long time only by extension, it is possible to realize a light condensing system with a low focal length and a long focal length. Therefore, it is not necessary to reduce the subject image to be formed while being extremely low. Therefore, an expensive image sensor having a pixel pitch reduced in proportion to the focal length as in a conventional low-profile image pickup apparatus is not required, and a high-resolution image can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
With reference to FIG. 1, the structure of the thin imaging device in Embodiment 1 of this invention is demonstrated. FIG. 1A is a perspective view of a thin imaging device, and FIG. 1B is a cross-sectional view taken along a center line 9 thereof.

  The imaging device includes a light guide path 1, an entrance mirror 2, an image sensor 3, an exit mirror 8, and an opening 33. An incident mirror 2 is provided on one end face of the light guide 1, and an exit mirror 8 and an image sensor 3 are provided on the other end face.

  Light from the subject 4 enters the imaging device through the opening 33, is reflected by the incident mirror 2, and is guided into the light guide path 1. The guided incident light 5 is condensed and formed on the image pickup surface 6 of the image pickup device 3 to pick up a subject image. The light guide 1 is a path through which incident light travels, and has a flat plate shape in the present embodiment and the following embodiments. A mirror surface 7 is provided on both main surface sides of the light guide 1 so as to reflect the incident light 5. That is, in the present invention, the mirror surface 7 is parallel or substantially parallel to an optical path (optical path indicated by a straight line 9 in FIG. 1) that linearly connects the entrance mirror 2 and the exit mirror 8 (or the image pickup device 3) in the light guide path 1. Is provided.

  The image pickup device 3 is disposed on the upper main surface of the light guide 1 so as to be opposed to the exit mirror 8, and the incident light 5 is reflected by the exit mirror 8 toward the upper main surface of the light guide 1 to take an image. An image included in a part of the incident light 5 that travels straight in the light guide 1 reaches the image sensor 3 as it is, and forms an image. An image included in the remaining incident light 5 that does not travel straight is reflected by the mirror surface 7 and is imaged. It reaches 3 and forms an image. An image signal obtained by the image sensor 3 is processed by an image processing circuit not shown in FIG. 1 and can be obtained as electrical image information.

  Here, as a material constituting the light guide 1, for example, an organic optical material such as polycarbonate resin, acrylic resin, cycloolefin resin, and epoxy resin, and inorganic optical material such as general optical glass are used. These optical materials generally have a refractive index of around 1.5. Further, as the optical material having a larger refractive index, a high refractive index glass or a high refractive index plastic such as a polymer containing sulfur may be used for the light guide 1. Note that the shape of the light guide 1 is not limited to a planar shape. If the incident light 5 reflected by the mirror surface 7 can reach the image sensor 3, a gentle curved surface is formed on the main surface of the light guide 1. You may have. By providing the light guide 1 with a curved surface, functions such as aberration correction can be provided.

  The shape of the incident mirror 2 is an arc-shaped elongated shape (strip shape) in a plane parallel to the main surface of the light guide 1 so that the incident light 5 is condensed toward the imaging surface 6. With this configuration, the incident light 5 is collected in a plane parallel to the main surface of the light guide 1. Further, as shown in FIG. 1B, the incident mirror 2 has a concave mirror shape even in the cross section, so that the incident light 5 can be condensed on the imaging surface 6 even in the cross section of the light guide path 1. As a matter of course, the function of condensing the incident light 5 with respect to the cross section of the light guide 1 can be performed not only by the incident mirror 2 but also by the emission mirror 8.

  According to such a configuration, the condensing optical system having a predetermined focal length can be configured by the incident mirror 2, and the optical path length of the condensing optical system from the incident mirror 2 through the light guide path 1 to the image sensor 3 can be reduced. Since it can be taken longer in the light guide path, there is a problem of resolution degradation due to reduction of the subject image due to shortening of the focal length of the condenser lens for the purpose of reducing the height, which was a problem in the conventional imaging device Can be avoided. That is, in the configuration of the embodiment according to the present invention, the light path for condensing can be long in the light guide path. Therefore, it is possible to configure a condensing optical system having a focal length comparable to that necessary for obtaining a high-resolution image with a conventional imaging device while maintaining a low profile. Therefore, in this imaging apparatus, the subject image formed on the imaging surface is not reduced to such an extent that imaging at a satisfactory resolution is impossible without using a higher-density imaging device. For this reason, it is possible to perform high-resolution imaging using an imaging device having a pixel pitch equivalent to the conventional one. Furthermore, the light guide path 1 serving as a condensing optical path can be thin, and the incident mirror 2 serving as a condensing optical system can also be configured with the same thickness as the light guide path 1. Thinning is possible. With this configuration, it is possible to obtain a high-resolution image while having a very low profile and thin optical system.

  Specifically, in the present embodiment, for example, the thickness h of the incident mirror 2 and the light guide 1 is 1 mm, the length L of the incident mirror 2 is 10 mm, and from the incident mirror 2 to the imaging position of the image sensor 3. When the optical element is designed to have an optical path length of 10 mm, and the image pickup device 3 is an elongated one having a thickness of 350 μm and an image pickup surface 6 of 8 mm × 1.2 mm, the optical system and the image pickup device 3 are included. The thickness can be reduced to 1.5 mm or less, and a high resolution equivalent to that obtained when a lens having a focal length of 10 mm is used in a conventional imaging apparatus can be obtained. Furthermore, even when an optical system with a long focal length is required, it can be dealt with by increasing the length of the light guide path 1 without increasing the thickness.

  On the other hand, if this thickness is to be realized with a conventional imaging device, the focal length of the lens must be about 1 mm or less, and the subject image formed is 10 times smaller than a 10 mm lens. It becomes difficult to obtain a high resolution. For example, assuming that the subject image is 1 mm × 1 mm and an image of 1 million pixels, that is, a so-called megapixel is obtained, the size of one pixel is 1 μm × 1 μm, and an image sensor such as a CCD or CMOS sensor having fine pixels is realized. In addition to being difficult, it is required to have a resolution in the order of the wavelength of light, and it is theoretically difficult to obtain a high-resolution image from the diffraction limit in the optical system.

  Next, the effect | action of the mirror surface 7 provided in both surfaces of the light guide 1 in this Embodiment is demonstrated, referring FIG. FIG. 2 is a cross-sectional view schematically showing how incident light propagates in the light guide 1. 2A to 2C show a case where the incident light 5 is directly reflected on the exit mirror 8 without being reflected by the mirror surface 7 and reflected to reach the image sensor 3. It can be seen that the image forming position changes according to the incident angle from the subject, and an image in the field of view can be captured. FIGS. 2D and 2E show a case where the incident light 5 is reflected and imaged once by the mirror surface 7 on the upper surface, and the incident light is reflected by the mirror surface 7 in this way. Even if 5 is not a field of view directly propagating through the light guide 1, an image of a field of view adjacent thereto can be formed. In addition, as an image obtained, in (a)-(c) and (c)-(e) of FIG. FIGS. 2F and 2G show a case where the incident light 5 is reflected by the mirror surface 7 a plurality of times, and an image with a wider viewing angle can be obtained as in the case of the single reflection. . Further, as shown in FIG. 2 (h), from the opposite side of the visual field shown in FIG. 2 (a) to FIG. 2 (g), that is, from the visual field shown in FIG. 2 (a) to FIG. Thus, it can be seen that an image of the left visual field can be obtained similarly. Here, the field of view and the viewing angle refer to a part or the whole of the object scene.

  FIG. 3 schematically shows the state of the subject image reflected by the mirror surface 7. The original subject image shown in FIG. 3A is divided into images with different fields of view depending on the number of reflections on the mirror surface 7, the difference in the mirror surface 7 to be reflected, and the like. As shown in FIG. 3B, the images of the respective fields of view are superimposed. In the present embodiment, the image processing circuit separates image information for each viewing angle, and performs processing for obtaining an original subject image as shown in FIG. 3A and 3C, one frame image is composed of five strip-shaped field-of-view images obtained by dividing one image in a single direction (vertically). Here, the central visual field image 503 is an image composed of components of the incident light 5 that has reached the image sensor 3 without being reflected by the mirror surface 7. The second and fourth field images 502 and 504 are images composed of components of incident light 5 that has been reflected once by the mirror surface 7 and reached the image sensor 3, and the first and fifth field images 501. Reference numerals 505 and 505 denote images composed of components of the incident light 5 that is reflected twice by the mirror surface 7 and reaches the image sensor 3.

  As in the present embodiment, by superimposing optical information from the subject 4 and forming an image on the image pickup device 3, the area of the image pickup surface 6 of the image pickup device 3 required for image pickup can be reduced. Thus, it can be made smaller than the imaging surface used when imaging the same field of view. Therefore, the image pickup device 3 itself can be further reduced in size, and a cost reduction effect for manufacturing the image pickup apparatus is also expected.

  As a method of separating image information for each viewing angle, there is a method of separating the image information according to the incident angle of incident light 5 incident on the image sensor 3. As can be seen from the optical paths of the incident light 5 incident from different viewing angles shown in FIG. 2, the incident light incident from different subject viewing angles also has different angles incident on the image sensor 3. Therefore, an original subject image can be obtained by providing means for separating the incident angle in the immediate vicinity of the image sensor 3 and performing image processing for separating the respective images.

  FIG. 4 shows an example of a technique for classifying the incident angle of light incident on the image sensor 3 by an optical technique. FIG. 4A shows the configuration of the optical system in the vicinity of the imaging surface 6 of the imaging device 3, and has a cylindrical curved surface on the front surface of the imaging device 3 so that the focal point is connected to the imaging surface 6. A large number of cylindrical lenses 10 are arranged in an array at an equal pitch. As can be seen from the figure, the incident light 5a from one field of view and the incident light 5b from another field have different angles of incidence, and the positions where the cylindrical lens 10 forms an image on the imaging surface 6 depend on the angle of incidence. Different. For this reason, an incident angle and a viewing angle can be distinguished from the position where this image is formed. Since the cylindrical lens 10 is exactly focused on the imaging surface 6, the light incident on any position of one cylindrical lens 10 is focused on the same position if the incident angle is the same. Viewing angle information can be separated.

  On the other hand, the configuration shown in FIG. 4B is a case where the cylindrical lens 10 is brought closer to the imaging surface 6 than in the case shown in FIG. 4A. In this case, both the incident lights 5a and 5b have a viewing angle. The image is formed on the imaging surface 6 as an almost intact image without depending on much. Therefore, in the case of FIG. 4A, the separation of the viewing angle is superior to that of the high resolution of the image, and in the case of FIG. 4B, the resolution of the image is superior to that of the separation of the viewing angle. For example, the cylindrical lens 10 is disposed in an intermediate positional relationship between FIG. 4A and FIG. 4B, and the position of the cylindrical lens 10 is between FIG. 4A and FIG. 4B. By taking a method such as making it variable, the viewing angle information can be separated by image calculation from a plurality of pieces of image information obtained from the respective positions, and the original image can be restored.

  Further, as shown in FIG. 4C, the cylindrical lens 10 is moved in the direction in which the plurality of cylindrical lenses 10 are arranged (parallel to the imaging surface 6), thereby forming an imaging position corresponding to the viewing angle, and the cylindrical lens 10. The image formed on the imaging surface 6 changes every moment according to both the information on the position of the light beam incident on the image plane. Image restoration can be performed. Naturally, as described above, a plurality of pieces of image information can be obtained by combining the movement in the direction in which the distance between the cylindrical lens 10 and the imaging element 3 is changed and the movement in the direction in which the cylindrical lenses 10 are arranged. You can also acquire and restore the original image.

  In the present embodiment, a cylindrical lens is used as a means for optically separating the incident angle information of the light incident on the image pickup device 3, but an optical device having a function of condensing a light beam in the direction of the incident angle to be separated. Similar effects can be obtained by using a system such as a Fresnel lens.

(Embodiment 2)
FIG. 5 is a diagram showing an optical configuration for selecting and separating the incident angle of the incident light 5 on the front surface of the imaging device 3 in the thin imaging device of Embodiment 2 of the present invention. The configuration in which the incident light 5 incident on the light guide 1 reaches the front surface of the image sensor 3 is the same as that in the first embodiment.

  In FIG. 5A, an optical slit array 20 having a slit portion 20a and a light shielding portion 20b is provided on the front surface of the imaging surface 6 of the imaging device 3 at a predetermined distance. As a result, the incident light 5a and 5b having different incident angles inevitably differ in the positions where the shade is dropped on the imaging surface 6, and images having different viewing angles can be separated.

  Here, since the light of the portion shielded by the light shielding portion 20b does not transmit, when the higher image resolution is to be obtained, the optical slit array 20 is arranged in the arrangement direction (see FIG. 4) like the cylindrical lens 10 in FIG. 5 (a) in the direction of the horizontal arrow) or by changing the distance between the optical slit array 20 and the imaging surface 6 (in the direction of the vertical arrow in FIG. 5 (a)), It is possible to perform image calculation and separate viewing angle information from the image information.

  In the present embodiment, an optical slit array is used, but other means may be used as long as the slit function is optically achieved. FIG. 5B shows a configuration in which a liquid crystal shutter 21 in which electrodes are arranged in a stripe shape in one direction is arranged on the front surface of the imaging surface 6. Similarly to the movement of the optical slit array 20, by sequentially scanning the lines through which light passes, it is possible to separate images with different viewing angles without moving parts. In addition, the width of the slit portion 21a of the liquid crystal shutter 21 (the portion of the liquid crystal shutter 21 that is controlled so that the light transmittance is approximately 1) is variable, and priority is given to the degree of image separation for each viewing angle. In such a case, the width can be narrowed, and when it is necessary to minimize the loss of energy of received light, the width can be set wide.

(Embodiment 3)
FIG. 6 is a cross-sectional view illustrating the thin imaging device of the third embodiment. In FIG. 6A, the configuration in which the mirror surface 7 is provided so that the light beam from the subject is reflected and guided by the incident mirror 2 to the light guide path 1 and reflected by both main surfaces of the light guide path is implemented. This is the same as the first embodiment. The present embodiment is different in that the incident light guided to the end face on the light receiving side of the light guide 1 is directly received by the image sensor 3 without providing the exit mirror 8 provided in the first embodiment. As described above, the exit mirror 8 in the first embodiment has an effect of reflecting the optical axis to the main surface side of the light guide 1 and facilitating the arrangement of the image sensor 3 on the plane. Can be arranged as shown in FIG. 6A, it is possible to obtain an image with a very thin optical system and high resolution without providing the exit mirror 8.

  Here, a method for separating image information from different viewing angles of the incident light 5 in the third embodiment will be described with reference to FIGS. FIG. 6B shows a case where incident light 5c, 5d, and 5e from different visual fields are incident on the same pixel of the image sensor 3. If this is the case, incident light with different fields of view cannot be separated. However, as shown in FIG. 6C, by changing the distance between the light guide 1 and the image sensor 3, the same pixel is focused on in FIG. 6C. The incident lights 5c, 5d, and 5e having different visual fields are focused on different pixels. As described above, it is possible to separate images with different viewing angles by image calculation from a plurality of pieces of image information in which the distance between the light guide path 1 and the image sensor 3 is changed, and to restore the original image.

(Embodiment 4)
FIG. 7 is a cross-sectional view showing the thin imaging device of the fourth embodiment. In FIG. 7A, the configuration in which the mirror surface 7 is provided so that the light beam from the subject is reflected and guided by the incident mirror 2 to the light guide path 1 and reflected by both main surfaces of the light guide path is implemented. This is the same as the first embodiment. The present embodiment is different in that the exit mirror 8 provided in the first embodiment is installed away from the end face of the light guide 1 on the image pickup device 3 side. The exit mirror 8 plays a role of reflecting the incident light 5 exiting from the light guide 1 and forming an image on the image sensor 3.

  Here, a method of separating image information from different viewing angles of the incident light 5 in the fourth embodiment will be described with reference to FIGS. 7B and 7C. FIG. 7B shows a case where incident light 5c, 5d, and 5e from different visual fields are incident on the same pixel of the image sensor 3. If this is the case, incident light with different fields of view cannot be separated. However, as shown in FIG. 7C, by changing the distance of the exit mirror 8 with respect to the light guide 1, the same pixel is obtained in FIG. The incident lights 5c, 5d, and 5e having different visual fields that are focused are focused on different pixels. As described above, it is possible to separate images with different viewing angles by image calculation from a plurality of pieces of image information when the distance of the exit mirror 8 with respect to the light guide 1 is changed, and to restore the original image.

  In the third embodiment, the operation principle is the same as when the image pickup device 3 is movable, but it has a lead-out wiring and a signal processing circuit, and does not move the unit of the image pickup device 3 having a complicated structure. Since it can respond by moving only a lightweight mirror with a simple structure, there is an effect that driving is easy.

(Embodiment 5)
FIG. 8 is a cross-sectional view showing a thin imaging device according to Embodiment 5 of the present invention. First, the configuration and operation will be described below with reference to FIG.

  An incident mirror 2 is provided on one end face of the light guide 1 that transmits light, and an image sensor 3 is provided on the other end face, and light from the subject is reflected by the incident mirror 2 and enters the light guide 1. The configuration in which the guided incident light 5 is focused and focused on the imaging surface 6 of the imaging device 3 to capture the subject image is the same as in the first embodiment. In the present embodiment, the specific configuration of the mirror surface 7 that reflects incident light 5 provided on both main surfaces of the light guide 1 is different from that of the first embodiment.

  In the present embodiment, an external medium 31 having a refractive index different from that of the light guide 1 is further provided outside the light guide 1. The refractive index (n1) of the medium constituting the light guide 1 is made larger than the refractive index (n2) of the external medium 31. In general, when a light beam is incident on the interface from a medium having a high refractive index to a medium having a low refractive index, the optical characteristic is that when the light beam enters the interface between two media at an angle larger than the critical angle, the light is totally reflected. There is. In the present embodiment, the function of the mirror surface 7 is realized at the interface between the light guide 1 and the external medium 31 by using this optical characteristic. That is, the mirror surface 7 according to the present embodiment totally reflects the incident light 5 reflected from the inside of the light guide 1 at a shallow angle (large incident angle) and propagates it to the image sensor 3 as in the first embodiment. The same effect is exhibited as a thin imaging device.

  Furthermore, since the mirror surface 7 of the present embodiment has the property that light incident at an incident angle smaller than the critical angle transmits through the mirror surface, the following effects can be further obtained. First, although the optical path of the incident light 5 shown in FIG. 8 represents an optical path under ideal conditions, in an actual imaging environment, there is scattered light or incident light from an unexpected direction, and the light guide path 1 So-called stray light is generated inside. Many of these stray lights are incident on the mirror surface 7 at random angles, and stray light having an incident angle smaller than the critical angle does not satisfy the total reflection condition determined by the refractive indexes n1 and n2 of the respective media. In this embodiment, the light is not reflected by the mirror surface 7 and does not reach the image sensor 3. Therefore, unnecessary light propagation can be prevented. In FIG. 8A, the light absorber 32 is provided to absorb unnecessary light that has not been reflected by the mirror surface 7, and further suppresses the propagation of unnecessary light such as scattered light. Is possible.

  Another new effect of the mirror surface 7 of the present embodiment will be described with reference to FIGS. 8B and 8C. FIG. 8B is a cross-sectional view in which the periphery of the incident mirror 2 of the present embodiment is enlarged, and FIG. 8C is a cross-sectional view in which the periphery of the exit mirror 8 is enlarged. In FIG. 8B, since the light incident from the subject enters the light guide path 1 made of a medium having a high refractive index from an external medium 31 having a low refractive index, it is transmitted while being refracted at the interface, and is reflected by the incident mirror 2. Since the angle formed with the mirror surface 7 is converted to a shallow direction, the light is reflected by the mirror surface 7 and propagated. As a result, as shown in the incident side opening 33 of the light guide 1, the mirror surface 7 can also be formed in the opening, and light from the outside is transmitted and incident light 5 reflected by the incident mirror 2 is reflected. Even the opening 33 is reflected by the mirror surface 7 and guided through the light guide 1. Similarly, as shown in FIG. 8C, the mirror surface 7 can be formed also in the opening 34 on the image pickup device 3 side, and the incident light 5 that has propagated is reflected by the mirror surface at an angle larger than the critical angle. 7 is incident on the mirror surface 7 at an angle smaller than the critical angle because the light is totally reflected toward the exit mirror 8 and reflected by the exit mirror 8. To reach.

  In addition, as a material which comprises the external medium 31, a fluorinated polymer is mentioned, for example. The fluorinated polymer has a refractive index n = 1.34, and is a material whose refractive index can be controlled by the degree of fluorination. In addition, the material which comprises the external medium 31 should just have a refractive index smaller than the refractive index n1 of the medium of the light guide 1.

  As a combination of the material used as the light guide 1 and the material used as the external medium 31, a combination in which the square of the refractive index n2 of the external medium 31 and the refractive index n1 of the light guide 1 are close to each other is incident light 5. Further, the external medium 31 has a thickness direction of 1/4 of the wavelength λ of the incident light 5, 3/4,. . . , Having an optical distance of about (2n−1) / 4 (n is a natural number) is a preferable combination for the antireflection effect of the incident light 5. Since the wavelength range of visible light is approximately 400 to 700 nm, taking the central wavelength 550 nm as an example, the thickness of the external medium 31 is approximately 140 nm, 410 nm,. . . However, this is preferable for the antireflection effect. However, even if the incident light 5 propagating in the light guide 1 is reflected at the interface, there is leakage of light to the external medium 31, so that the light absorbing material 32 exists at a distance shorter than the wavelength. There is a risk of loss of light. Therefore, it is preferable that the external medium is sufficiently thick from the viewpoint of preventing light loss due to light leakage.

  As described above, according to the configuration of the present embodiment, not only the same effects as in the first embodiment can be obtained, but also the propagation of unnecessary light can be suppressed, the influence of disturbance light and scattering can be suppressed, and By providing the mirror surface 7 at both the entrance and exit sides of the optical path 1, optically efficient imaging can be performed, and imaging with good quality can be performed.

  In the present embodiment, the external medium 31 of the light guide 1 need not be filled with an optical substance, and may be a gap (air). Since the refractive index of the air gap is approximately equal to the refractive index of the vacuum, and therefore n2 = 1, by using an optical medium for the light guide path 1, the condition of n1> n2 must be satisfied and the mirror surface 7 should be configured. Can do.

(Embodiment 6)
FIG. 9 is a cross-sectional view showing a thin imaging device according to Embodiment 6 of the present invention. The configuration and operation will be described below with reference to FIG.

  In FIG. 9A, each configuration is the same as that of the fifth embodiment (FIG. 8A), and the refractive index (n1) of the medium constituting the light guide path 1 is set as the light guide section of the light guide path 1. By making it larger than the refractive index (n2) of the external medium 41, the incident light 5 that satisfies the total reflection condition is reflected by the refractive index difference of the optical medium, and the mirror surface 7 is configured. Here, the difference from the fifth embodiment is that when the medium 41 that can change the refractive index n2 is used as an external medium and the incident light 5 is to be reflected, n2 <n1, and the reflection is not desired. By setting n2 ≧ n1, reflection / non-reflection can be selectively controlled. A liquid crystal material is used as such a material, and although not shown, the liquid crystal is driven by a striped liquid crystal drive electrode to change its refractive index so that the reflection of incident light 5 can be partially turned on and off. Yes. By doing so, it is possible to separate the viewing angle information of the incident light from a viewpoint different from that of the previous embodiments. The operation will be described with reference to FIGS. In FIGS. 9B to 9E, reference numeral “42” indicates the external medium 41 controlled to be in a state (reflection state) in which incident light can be reflected.

  First, the incident light 5 that reaches the imaging device 3 directly without being reflected by the mirror surface 7 in the light guide 1 is always guided. Therefore, if the mirror surfaces 7 on both sides of the light guide 1 are brought into a non-reflective state, only the image of the field of view directly guided is picked up by the image sensor 3.

  Next, as shown in FIG. 9B, in the case of incident light that is reflected once and guided by one mirror surface 7 in the light guide 1, only the corresponding mirror surface 7 is reflected (42). ) To obtain an image in which the directly guided light image and the reflected and guided image are overlapped, and incident light from other fields of view is always non-reflective. The light is not guided unless reflected by the mirror surface 7. Therefore, by subtracting the above-described image information in the case of direct arrival from the image obtained by the image sensor 3, only the image information of the field of view reflected and guided once can be obtained.

  Furthermore, when the inside of the light guide 1 is reflected twice as shown in FIG. 9 (c), and when the inside of the light guide 1 is reflected three times as shown in FIGS. 9 (d) and 9 (e) Since each field of view has a unique reflection pattern, it is possible to extract only image information of the field of view by controlling reflection / non-reflection of the mirror surface 7 according to the field of view. Similarly, it is possible to obtain image information by sequentially classifying an image of a field of view having a larger number of reflections.

  According to the classification of the visual field information by this method, an image that is easily classified for each visual field angle without a movable part such as vibrating a lens or a slit without providing an optical visual field angle classification means on the front surface of the image sensor 3. Information can be obtained.

  In the present embodiment, the magnitude relationship between the refractive index (n1) of the light guide 1 and the refractive index (n2) of the external medium 41 is changed by controlling the refractive index (n2) of the external medium. If a medium whose refractive index (n2) can be changed in multiple stages is used as the external medium 41, the critical angle for total reflection of light at the interface can be changed in multiple stages, so that the image information can be used separately. It is also possible to do.

  In the present embodiment, the reflection / non-reflection of the mirror surface 7 is controlled by changing the refractive index of the liquid crystal. However, any method that can partially control the reflection / non-reflection of light is used. The effect is obtained.

(Embodiment 7)
FIG. 10 is a cross-sectional view showing a thin imaging device according to Embodiment 7 of the present invention. The configuration and operation will be described below with reference to FIG. FIG. 10A is a top view of the image pickup apparatus according to the present embodiment as viewed from the side on which light from the subject is incident, and FIG. 10B is a cross-sectional view, and the incident mirror 2 and the image pickup element, respectively. 3 schematically represents the relationship with the third imaging surface 6.

  The basic configuration is the same as that of the first embodiment, but the configuration of the incident mirror 2 is different. In the first embodiment, the incident mirror has a shape curved in an arc shape (see FIG. 1), but in the present embodiment, the incident mirror is configured in a linear shape, and the incident mirrors 2 are the same as each other or It comprises a plurality of partial mirrors 2a, 2b,... Having different curvatures. As the surfaces of the partial mirrors 2a, 2b,... Move away from the vicinity of the central axis, the radius of curvature increases, and incident light incident on each curved surface is collected at the center of the imaging surface 6. The curvature and reflection direction of each mirror 2a, 2b,... Are designed.

  In this way, the incident mirror 2 can also be constituted by a plurality of mirror partial surfaces having different curvatures in the respective portions 2a, 2b,... A condensing optical system having a long aperture length and a high aperture ratio that cannot be covered with a mirror is possible. Further, as in the example of FIG. 10A, the opening of the incident mirror 2 can be arranged in a straight line.

(Embodiment 8)
FIG. 11 is a top view and a cross-sectional view showing a thin imaging device according to Embodiment 8 of the present invention. The configuration and operation will be described below with reference to FIG. FIG. 11A is a top view of the imaging apparatus according to the present embodiment as viewed from the side on which light from a subject is incident, and FIG. 11B is a cross-sectional view.

  The basic configuration is the same as that of the first embodiment, but in this embodiment, a condensing lens 51 for condensing light incident from the subject is disposed on the subject-side front surface of the incident mirror 2. Is different. In the case of FIG. 11, a linear plane mirror is used as the incident mirror 2, and the condensing function is given to the condensing lens 51. Similarly to the incident mirror 2 in the seventh embodiment, the condensing lens 51 is designed so that the phase of the lens 51 is divided into a large number and the positions of the respective portions 151a, 151b, 151c. doing. The curvatures of the respective portions 151a, 151b, 151c... Of the lens 51 may be different in the longitudinal direction and the width direction of the lens 51, or may be the same curvature. Any form of lens may be used as long as the light transmitted through the respective portions of the lens 51 is successfully collected at a predetermined focal position. By partially dividing the condenser lens 51 in this way, the thickness of the condenser lens 51 can be suppressed, and the imaging apparatus can be made thin even if the incident mirror 2 does not have a condensing function. Can do.

  As described above, the condensing optical path can be taken in the length direction of the light guide path 1 without providing the incident mirror 2 with a condensing function, so that the thin condensing lens 51 having a long focal length can be provided. It can be used, and a similar effect can be obtained that an image with a higher resolution than in the prior art can be obtained.

  In the present embodiment, the incident mirror 2 is a plane mirror, but the same effect can be obtained even if the condensing optical system is configured in a complementary manner by using both the condensing lens 51 and the incident mirror 2 as curved surfaces. . For example, the incident mirror 2 is formed in an arc shape to collect light in a direction parallel to the main surface of the light guide 1, and the condensing lens 51 collects light in a direction perpendicular to the main surface of the light guide 1. In this case, the condensing lens 51 can have a cylindrical lens shape having a convex curved surface only in the width direction of the opening 33, so that the condensing lens 51 can be easily thinned.

(Embodiment 9)
12A and 12B are a top view and a cross-sectional view showing a thin imaging device according to Embodiment 9 of the present invention. The configuration and operation will be described below with reference to FIG. FIG. 12A is a top view of the imaging apparatus according to the present embodiment as viewed from the side on which light from a subject is incident, and FIG. 12B is a cross-sectional view.

  As in the eighth embodiment, the basic configuration is a configuration in which a condenser lens 51 is disposed on the front surface of the incident mirror 2. In the present embodiment, the light guide path is divided into a light guide path 1a and a light guide path 1b. Mirror surfaces 7a are formed on both main surfaces of the light guide path 1a. The incident mirror 2 is fixed to one end of the light guide path 1a, and the incident light 5 guided by the incident mirror 2 is reflected and guided by the mirror surface 7a. On the other hand, the light guide path 1b is composed of a cavity sandwiched between the mirror surfaces 7b constituting both main surfaces, and guides the incident light 5 guided through the light guide path 1a to the image pickup device 3 while being reflected by the mirror surface 7b. Shine.

  Thus, by using the cavity provided with the mirror surface as the light guide path, it is possible to move the mirror surface 2 to the light collecting optical axis side as indicated by the arrow shown in FIG. By making the incident mirror 2 movable, the distance between the incident mirror 2 and the image sensor 3 can be adjusted, the focus can be adjusted according to the distance of the subject, and higher-quality imaging can be performed. it can. Although not shown, as a matter of course, it is possible to adjust the focus even in a configuration in which the incident mirror is fixed and the image pickup device 3 and the exit mirror 8 are movable, and similarly, high-quality image pickup is performed. be able to.

  Furthermore, in the present embodiment, the condenser lens 51 provided on the front surface of the incident mirror 2 is divided into a plurality of areas 51a, 51b, 51c. Thereby, it is possible to switch the lens that makes the light of the subject incident on the incident mirror 2 by moving the incident mirror 2. By making the focal lengths of the lenses 51a, 51b, and 51c different from each other, it is possible to perform zooming by switching lenses having different focal lengths. In the example of FIG. 12, the condensing lens 51a is switched in three steps, that is, telephoto, 51b is standard, and 51c is wide, and each lens has a different focal length. By moving the incident mirror 2 in each lens area, the above-described focus adjustment can be performed, and both zoom and focus adjustment can be achieved.

  In the present embodiment, the condensing lens 51 is divided into three stages. However, by further dividing the condenser lens 51 into multiple stages, it is possible to perform a zoom that is continuously close. In the present embodiment, the focus is also adjusted by moving the incident mirror 2, but the focus can be adjusted by adjusting the distance between the incident mirror 2 and the image sensor 3. Therefore, the image pickup device 3 side may be movable. When focus adjustment is performed on the image pickup device 3 side, the incident mirror 2 serves as a zoom adjustment center. Therefore, the number of divisions of the condensing lens can be increased to enable smoother zooming.

  In the present embodiment, the surface of the incident mirror 2 is also given a curvature, and the light is condensed by a combination with the condensing lens 51. For example, in the example of FIG. 12, the incident mirror surface 2 is arranged in an arc shape in accordance with the focal length of the most telephoto field of view, and condensing light, and a simple flat glass is used for the most telescopic condensing lens 51a. The lens is not focused. Thereby, since it is not necessary to give curvature to the part of 51a, it becomes possible to make thin. Further, in the condensing lenses 51b and 51c in other areas, a lens having a shorter focal length and a larger curvature is required as the width becomes wider. However, by providing a condensing function on the surface of the incident mirror 2, The curvature of the condenser lens can be reduced, the entire condenser lens system can be made thin, and a thin imaging device can be realized.

  In the present embodiment, the mirror surface 7a is moved in conjunction with the incident mirror 2. However, for example, when light is incident from the condensing lens 51a, openings are formed in the other condensing lens portions 51b and 51c. However, since these portions have the mirror surface 7a, the outside light is blocked and the incident light 5 in the light guide path 1a is reflected.

(Embodiment 10)
FIG. 13 is a cross-sectional view illustrating a thin imaging device according to Embodiment 10 of the present invention.

  In the basic configuration of the present embodiment, the mirror surface 7 of the light guide 1 is configured by the difference in refractive index between the medium in the light guide and the external medium 31 as in the fifth embodiment. A light absorbing material 32 is disposed outside the surface to absorb unnecessary light.

  Here, the light guide 1 has a configuration in which a liquid is filled in a space between both external media 31, and the refractive index of the liquid filled in the light guide 1 is higher than the refractive index of the external medium 31. The mirror surface 7 is realized by increasing the height. By doing in this way, it becomes possible to move the block which comprises the entrance mirror 2 within the light guide 1.

  For the liquid to be filled, if the external medium 31 is an optical material having a refractive index as low as that of a fluoropolymer, for example, ordinary organic oil or silicone oil can be used. For example, Shin-Etsu silicone optical silicone oil provides a refractive index of about 1.47. As a liquid having a higher refractive index, for example, there is a standard refractive liquid manufactured by Cargill, and Series B has a refractive index of about 1.7.

  In the present embodiment, condenser lenses 51a, 51b, 51c comprising a plurality of areas are arranged in front of the incident mirror 2 as in the ninth embodiment, and the incident mirror 2 moves in the light guide 1. Thus, the zoom function and the focus function can be realized as in the ninth embodiment.

  In the present embodiment, since the mirror function is realized by the difference in refractive index, it is not necessary to divide the light guide as in the ninth embodiment, and the mirror surface 7 is also formed in the opening where the condenser lens is disposed. By moving the incident mirror 2 to a predetermined condenser lens portion (51a, 51b, or 51c), the condenser lens to be used can be designated. For example, as shown in the drawing, the incident light incident from the condenser lens 51 a is guided into the light guide path 1, reflected by the mirror surface 7 at the aperture 33 of the condenser lens such as 51 b and 51 c, and guided to the image sensor 3. Therefore, unnecessary incident light is absorbed by the light absorbing material 32 or transmitted outside the light guide path 1.

(Embodiment 11 <Card type camera>)
FIG. 15 is a perspective view of a card-type camera 60 using the thin imaging device described in the above embodiment. All of the thin imaging devices described in the above embodiments are low-profile. Therefore, any of these thin imaging devices is suitable for use as the imaging device 61 of the card type camera 60 according to the present embodiment. In this embodiment, as an example, the thin imaging device according to Embodiment 6 shown in FIG. 9 is used.

  The card-type camera 60 has a thickness H (H: about 0.5 mm ≦ H ≦ 3.0 mm), and has dimensions similar to those of a generally distributed credit card in length and width. The reason why the external method of the camera 60 is set to such a size is that the user's convenience of storing and carrying the camera 60 is taken into consideration. The shape and dimensions of the camera 60 are not limited to those shown in this figure. The camera 60 incorporates a thin imaging device 61, and the opening 33 is exposed so that light from the outside can enter. On the surface of the camera 60, a shutter button 62 and an external interface 63 are arranged. The operator can take an image by pressing the shutter button 62, and the image is taken by connecting an information processing device (not shown) to the external interface 63 and stored in a storage device (not shown) in the main body. Image data can be sent to an information processing apparatus or the like. The shutter button 62 can be configured by a general pressure sensor. The external interface 63 may be a contactless external interface 63 or a non-contact external interface.

  FIG. 16 shows a block diagram of the camera 60. The operation unit 162 including the shutter button 62 (FIG. 15) is connected to the controller 164. In addition to the operation unit 162, the controller 164 is connected to an imaging unit 161, an image processing unit 165, a storage unit 166, and an external interface (I / F) unit 163. The controller 164 includes a processor and a memory inside, and can execute a program necessary for controlling the camera. The imaging unit 161 including the thin imaging device 61 can capture an image under the control of the controller 164. Image information obtained by imaging is sent to the image processing unit 165. The image processing unit 165 performs predetermined processing on the received image information under the control of the controller 164. The processed image information is sent to the storage unit 166 and stored as image data. The stored image data can be transmitted to the outside from the external I / F unit 163 under the control of the controller 164. The storage unit 166 preferably includes a nonvolatile memory.

  FIG. 17 is a diagram illustrating an example of imaging of the subject 70 using the camera 60. An operator (not shown) points the opening 33 toward the subject 70 and presses the shutter button 62 with a finger. Thereby, imaging is performed. Further, the camera 60 may provide a finder to the operator by providing a window (not shown) that transmits light in a part of the camera 60.

  When the shutter button 62 is pressed, the camera 60 performs imaging, converts optical image information from the subject 70 into an electrical signal in the imaging unit 161, and converts the image information converted into an electrical signal into the image processing unit 165. By processing, it is converted into image data, and the image data is stored in the storage unit 166. FIG. 18 shows an example of an image represented by image data stored in the storage unit 166. In this figure, lines dividing the image into nine parts (image segments 71a to 71i) are included in the image, but these lines are not included in the image data. These lines should be understood as auxiliary lines for helping understanding of processing related to image data generation described later.

  With reference to FIGS. 19 and 20, imaging by the thin imaging device 61 (see FIG. 9) included in the imaging unit 161 and information processing in the image processing unit 165 will be described. As described above, the thin imaging device according to the sixth embodiment uses the medium 41 or 42 that can control reflection and non-reflection for each section as the mirror surface 7. Therefore, the camera 60 executes a plurality of imaging by changing the reflection / non-reflection state pattern of the mirror surface 7 with respect to the imaging for one frame, and a plurality of imaging corresponding to each reflection / non-reflection state pattern. Image information is taken out as an electrical signal by the image pickup device 3, and the plurality of pieces of image information are sent to the image processing unit 165, and predetermined processing is performed in the image processing unit 165 to generate image data for one frame.

  When the controller 164 recognizes the pressing of the shutter button 62 included in the operation unit 162 by the operator (step S101 in FIG. 20), the controller 164 instructs the imaging unit 161 to execute the first to ninth imaging ( FIG. 20 step S102). FIG. 19A to FIG. 19I are diagrams illustrating images represented by image information created by the imaging unit 161 in imaging for one frame configured by the first to ninth imaging. Strictly speaking, these pieces of image information are image information captured at different times. However, since the imaging time intervals are very close, it can be recognized as image information captured at the same time. In addition, the temporal order of image information capture is not particularly specified. In this embodiment, image data for one frame is created by nine times of imaging, but the number of times of imaging can be arbitrarily set.

  First, the first imaging is performed by setting all the media constituting the mirror surface 7 of the thin imaging device (see FIG. 9) to the non-reflecting state 41. In the first imaging, only the light that has directly passed through the light guide path and directly enters the exit mirror 8 without entering the mirror surface 7 forms an image on the image sensor 3. FIG. 19A shows an image 72a obtained in the first imaging. This corresponds to the central image segment 71a in FIG.

  Next, one mirror surface 7 of the two mirror surfaces 7 is entirely in the reflecting state 42 and the other mirror surface 7 is set in the non-reflecting state 41 to perform the second imaging (see FIG. 9B). In this second imaging, the light that has entered the exit mirror 8 without being reflected by the mirror surface 7 and the light that has been reflected once by the mirror surface 7 and entered the exit mirror 8 form an image on the image sensor 3. FIG. 19B shows an image 72b obtained in the second imaging. This corresponds to an image in which the image segment 71a in FIG. 18 and the image segment 71b inverted in the vertical direction are superimposed.

  Next, the two mirror surfaces 7 are partially brought into a non-reflective state 41 and a reflective state 42, respectively, and third imaging is performed (see FIG. 9C). The reflection / non-reflection pattern of the mirror surface 7 in the third imaging is such that the light incident on the exit mirror 8 is reflected twice by the mirror surface 7 and the light incident on the exit mirror 8 without being reflected by the mirror surface 7. It is a pattern composed of light incident on the exit mirror 8. FIG. 19C shows an image 72c obtained in the third imaging. This corresponds to an image in which the image segment 71a and the image segment 71c in FIG. 18 are superimposed.

  Next, the two mirror surfaces 7 are partially made into a non-reflective state 41 and a reflective state 42 respectively in a pattern different from the third imaging, and the fourth imaging is performed (see FIG. 9D). The reflection / non-reflection pattern of the mirror surface 7 in the fourth imaging is such that light incident on the exit mirror 8 is reflected by the mirror surface 7 three times with light incident on the exit mirror 8 without being reflected by the mirror surface 7. It is a pattern composed of light incident on the exit mirror 8. FIG. 19D shows an image 72d obtained in the fourth imaging. This corresponds to an image in which the image segment 71a in FIG. 18 and the image segment 71d inverted in the vertical direction are superimposed.

  Next, the two mirror surfaces 7 are partially brought into a non-reflective state 41 and a reflective state 42, respectively, in a pattern different from the second and third imaging, and the fifth imaging is performed. The reflection / non-reflection pattern of the mirror surface 7 in the fifth imaging is such that light incident on the exit mirror 8 is reflected by the mirror surface 7 four times with light incident on the exit mirror 8 without being reflected by the mirror surface 7. It is a pattern composed of light incident on the exit mirror 8. FIG. 19E shows an image 72e obtained in the fifth imaging. This corresponds to an image in which the image segment 71a and the image segment 71e in FIG. 18 are superimposed.

  Further, sixth to ninth imaging is performed. The sixth imaging is an imaging performed with a pattern obtained by inverting the reflection / non-reflection pattern state of the mirror surface 7 of the thin imaging device in the second imaging. FIG. 19F shows an image 72f obtained in the sixth imaging. This corresponds to an image in which the image segment 71a in FIG. 18 and the image segment 71f inverted in the vertical direction are superimposed.

  The seventh imaging is imaging performed with a pattern obtained by inverting the state of the reflection / non-reflection pattern of the mirror surface 7 of the thin imaging device in the third imaging. FIG. 19G shows an image 72g obtained in the seventh imaging. This corresponds to an image in which the image segment 71a and the image segment 71g in FIG. 18 are superimposed.

  Similarly, the eighth imaging is imaging performed with a pattern (see FIG. 9E) obtained by inverting the state of the reflection / non-reflection pattern of the mirror surface 7 of the thin imaging device in the fourth imaging. FIG. 19 (h) shows an image 72h obtained in the eighth imaging. This corresponds to an image in which the image segment 71a in FIG. 18 and the image segment 71h inverted in the vertical direction are superimposed.

  Similarly, the ninth imaging is an imaging performed with a pattern obtained by inverting the state of the reflection / non-reflection pattern of the mirror surface 7 of the thin imaging device in the fifth imaging. FIG. 19 (i) shows an image 72i obtained in the ninth imaging. This corresponds to an image in which the image segment 71a and the image segment 71i in FIG. 18 are superimposed.

  The image information obtained by the first to ninth imaging is then sent to the image processing unit 165. The image information sent to the image processing unit 165 is processed by the image processing unit 165 and converted into image data for one frame (step S103 in FIG. 20). First, the image information obtained by the first imaging is subtracted from the image information obtained by the second to ninth imaging, and further, the images obtained by the second, fourth, sixth, and eighth imaging. The information is processed so that it is turned upside down. Then, after adjusting the brightness and the like of the first image information and each processed image information, the image information is connected in the vertical direction to generate image data for one frame.

  The created image data is stored in the storage unit 166 (step S104).

  The card-type camera of this embodiment uses the low profile of the thin imaging device. If the advantage of being thin is not impaired, it is not necessary to have a card shape.

  Further, the thin imaging device and the camera according to the present invention are not limited to capturing a still image, and may be used for capturing a dynamic image.

  Further, the card type camera may have a credit card function. Furthermore, the cardholder's face information is provided in the main body, and when the credit function is used, the user's face is imaged by the camera function, and the authentication result is output from the external interface, thereby authenticating the user. Good.

  Further, the thin imaging device according to the present invention may be used as an imaging device for an endoscope probe by utilizing its low profile.

  The thin imaging device of the present invention can easily realize a condensing optical system having a long focal length in an extremely thin light guide, and can realize imaging with high resolution. It is useful as an imaging device such as a camera module.

1 is a perspective view and a sectional view taken along a center line of a thin imaging device according to Embodiment 1 of the present invention. Sectional drawing showing a mode that incident light propagates in the inside of the light guide of the thin imaging device in Embodiment 1 of this invention. FIG. 3 is a schematic diagram showing a state of reconstruction of a subject image in the thin imaging device according to Embodiment 1 of the present invention. Sectional drawing showing the method of classifying the incident angle of light in the thin imaging device in Embodiment 1 of this invention Sectional drawing showing the method of classifying the incident angle of light in the thin imaging device in Embodiment 2 of this invention Sectional drawing of the thin imaging device in Embodiment 3 of this invention Sectional drawing of the thin imaging device in Embodiment 4 of this invention Sectional drawing of the thin imaging device in Embodiment 5 of this invention Sectional drawing of the thin-type imaging device in Embodiment 6 of this invention A top view and a cross-sectional view of a thin imaging device according to Embodiment 7 of the present invention The top view and sectional drawing of the thin-type imaging device in Embodiment 8 of this invention A top view and a cross-sectional view of a thin imaging device according to Embodiment 9 of the present invention Sectional drawing of the thin-type imaging device in Embodiment 10 of this invention Sectional view of a conventional imaging device The perspective view of the card type camera in Embodiment 11 of this invention Block diagram of a card type camera according to Embodiment 11 of the present invention Example diagram of imaging by card type camera in Embodiment 11 of the present invention The figure of the example of a subject image imaged with the card type camera in Embodiment 11 of the present invention The figure of the example of a subject image imaged with the card type camera in Embodiment 11 of the present invention Flowchart of image formation in card type camera in Embodiment 11 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light guide 2 ... Incident mirror 3 ... Imaging device 4 ... Subject 5 ... Incident light 6 ... Imaging surface 7 ... Mirror surface 8 ... Ejection mirror 60 ...・ Card type camera 70 ... Subject

Claims (40)

An opening,
An incident mirror that simultaneously reflects incident light incident from the subject through the opening;
A light guide for guiding incident light reflected by the incident mirror;
A mirror surface provided on at least a part of the surface of the light guide;
At least a first section that is a part of the subject guided in the light guide without being reflected by the mirror surface, and guided in the light guide by being reflected at least once by the mirror surface. A thin image pickup device comprising: an image pickup device that simultaneously receives light in a state where a second section that is another part of the subject is superimposed.   The thin imaging device according to claim 1, wherein the light guide path has a substantially flat outer shape having two main surfaces parallel to each other.   The incident mirror includes one or a plurality of mirrors for condensing light incident on the incident mirror at a predetermined focal position in the light guide or in the vicinity of an exit end of the light guide. Item 2. The thin imaging device according to Item 1.   The thin imaging apparatus according to claim 1, wherein the incident mirror has a strip shape.   The thin imaging apparatus according to claim 3, wherein the incident mirror has an arcuate shape centered on the predetermined focal position.   The thin imaging device according to claim 3, wherein the plurality of mirrors constituting the incident mirror have an arc shape centered on the same focal position.   The one or more mirrors of the incident mirror are arranged in a line in a direction perpendicular to a main axis connecting the center of the incident mirror and the predetermined focal position. 4. The thin imaging device according to 3. The incident mirror has a cross-section that is at least partially concave.
The thin imaging apparatus according to claim 1, wherein the incident mirror condenses light from the subject at a predetermined focal position by the concave portion.   2. The thin imaging apparatus according to claim 1, wherein the incident side lens is disposed in the vicinity of the incident mirror on an optical path from the subject to the incident mirror. The incident side lens has a surface with a predetermined curvature,
The thin imaging apparatus according to claim 9, wherein the incident side lens collects light incident on the incident mirror.   The thin imaging apparatus according to claim 9, wherein the incident mirror has a reflecting surface that is substantially flat. Furthermore, an exit mirror is disposed near the exit end of the light guide,
The thin imaging apparatus according to claim 1, wherein the emission mirror reflects light emitted from the emission end and guides the light to the imaging element.   The thin imaging device according to claim 1, wherein a distance between the imaging device and the incident mirror is variable.   The thin image pickup device according to claim 13, wherein the image pickup device is slidable substantially parallel to a traveling direction of incident light in the light guide path.   The thin imaging apparatus according to claim 13, wherein the incident mirror is slidable substantially parallel to a traveling direction of incident light in the light guide path. And a plurality of incident side lenses on the optical path from the subject to the incident mirror and in the vicinity of the incident mirror,
The thin imaging apparatus according to claim 15, wherein an incident side lens through which light incident on the incident mirror is transmitted can be selected by sliding the incident mirror.   The image processing apparatus further includes means for optically separating image information including a plurality of optical image information of the visual field superimposed on the incident light into optical image information for each visual field. The thin imaging device according to claim 1. The means for sorting is arranged on the front surface of the image sensor,
The thin-film imaging device according to claim 17, wherein the classifying unit classifies image information included in the incident light incident on the imaging device based on an incident angle with respect to the imaging device.   The thin-film imaging device according to claim 18, wherein the means for sorting is a plurality of cylindrical lenses arranged in an array on the front surface of the imaging device and separated from the imaging device by a predetermined distance. The plurality of cylindrical lenses are movable in the direction of the distance to the imaging device and / or in the arrangement direction of the array of cylindrical lenses,
By the relative displacement of the cylindrical lens with respect to the image sensor, the image information including a plurality of optical image information of the visual field superimposed on the incident light is separated into optical image information for each visual field. The thin imaging device according to claim 19, wherein:   19. The thin imaging device according to claim 18, wherein the means for sorting is one or a plurality of slits arranged in an array on the front surface of the imaging device at a predetermined distance from the imaging device. apparatus. The array of slits is movable in the direction of the distance to the image sensor and / or in the array direction of the slits,
Due to the relative displacement of the array of slits with respect to the imaging device, image information including a plurality of optical image information of the field of view superimposed on the incident light is optical image information for each field of view. The thin imaging device according to claim 21, wherein the thin imaging device is sorted. The array of slits has a liquid crystal shutter;
The thin imaging device according to claim 21, wherein an optical function as a slit is realized by selectively turning on and off each of the liquid crystal shutters. Each of the liquid crystal shutters can sequentially change the on / off state,
As a result, the liquid crystal shutter changes the portion through which light is transmitted, and the image information included in a state in which the optical image information of the plurality of fields of view is superimposed on the incident light is optically displayed for each field of view. The thin image pickup device according to claim 23, wherein the thin image pickup device is classified into target image information. The means for sorting is a means for moving the imaging device in a direction perpendicular to the imaging surface and / or in a direction parallel to the imaging surface,
Based on the change of the image to be captured due to the movement of the image sensor, the image information included in the incident light in a state where a plurality of optical image information of the field of view is superimposed on each other is converted into optical image information for each field of view. The thin imaging device according to claim 17, wherein the thin imaging device is classified. Furthermore, an exit mirror that reflects light emitted from the light guide and forms an image on the image sensor is disposed near the exit end of the light guide,
The means for sorting is a means for moving the exit mirror in the direction of the distance from the light guide,
Based on the change in the captured image due to the movement of the exit mirror, the image information that is included in the incident light in a state where the optical image information of the plurality of fields of view is superimposed on each other is converted into optical image information for each field of view. The thin imaging device according to claim 17, wherein the thin imaging device is classified. Furthermore, an external medium having a refractive index smaller than the refractive index of the light guide path outside the light guide path,
The thin imaging apparatus according to claim 1, wherein the mirror surface is configured by an interface between the light guide path and the external medium.   28. The thin imaging apparatus according to claim 27, wherein the external medium is air.   28. The thin imaging device according to claim 27, wherein a light absorbing member is provided outside the external medium. The light guide has the mirror surface in the vicinity of the opening,
The thin film imaging device according to claim 1, wherein the mirror surface allows light incident on the opening to be transmitted from the outside toward the opening. The light guide has the mirror surface in the vicinity of the exit end of the light guide,
2. The thin imaging apparatus according to claim 1, wherein the mirror surface allows light emitted from the light guide path to be transmitted outward.   2. The thin imaging device according to claim 1, wherein reflection / non-reflection of the mirror surface can be individually controlled for each part of the mirror surface. Furthermore, it has means for separating image information included in a state in which a plurality of optical image information of the plurality of fields of view is superimposed on the incident light into optical image information for each field of view,
The thin imaging device according to claim 32, wherein the means for classifying is a means for controlling individual reflection / non-reflection for each part of the mirror surface constituting the plurality of mirror surfaces. Further, an external medium is provided outside the light guide path,
The mirror surface is composed of an interface between the light guide and the external medium,
Controlling the reflection / non-reflection of the mirror surface by controlling the magnitude relationship between the absolute refractive index of the light guide and the absolute refractive index of the external medium and / or the difference between the absolute refractive indexes of the light guide path. The thin imaging device according to claim 32, characterized in that Furthermore, it has a liquid crystal outside the light guide,
The mirror surface is composed of an interface between the light guide path and the liquid crystal,
The thin imaging device according to claim 32, wherein reflection / non-reflection of the mirror surface is controlled by controlling an absolute refractive index of the liquid crystal.   The thin imaging device according to claim 1, wherein the light guide path has a gap in at least a part thereof. The void is filled with a liquid;
Further, an external medium having an absolute refractive index smaller than the absolute refractive index of the liquid is outside the light guide,
37. The thin imaging device according to claim 36, wherein the mirror surface is configured by an interface between the light guide path and the external medium. A thin imaging device according to claim 1;
An operation unit capable of inputting an imaging execution instruction of the operator;
An image processing unit that executes predetermined processing on image information from the thin imaging device to generate image data;
A storage unit for storing the image data;
A camera comprising: a controller that controls the thin imaging device, the image processing unit, and the storage unit.   A camera comprising the thin-type imaging device according to claim 1 built in a card-type case. Guiding a first section, which is a part of incident light from a subject, in the light guide, and directly entering the image sensor without being reflected by a mirror surface formed on the surface of the light guide;
Guiding the second section, which is another part of the incident light from the subject, in the light guide, reflecting it at least once by a mirror surface formed on the surface of the light guide, and entering the imaging element;
And a step of superimposing at least the image of the first section and the image of the second section and simultaneously outputting from the image sensor.

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