Optical module, optical device, and method for manufacturing optical module

Abstract

This optical module includes a splitting surface that transmits part of incident light and reflects at least part of the incident light different from the part of the incident light that is transmitted, the optical module imaging each of the light transmitted through the splitting surface and the light reflected by the splitting surface. The optical module comprises a first optical system and a second optical system. The first optical system comprises, in order from the object side, a forward lens group, an optical path-splitting member having a splitting surface, and a first backward lens group that has a positive refracting power and on which the light transmitted through the splitting surface is incident. The second optical system comprises, in order from the object side, a forward lens group, an optical path-splitting member, and a second backward lens group that has a positive refracting power and on which the light reflected by the splitting surface is incident. One of the first optical system and the second optical system is configured to have an aperture stop on the splitting surface or on the image side of the splitting surface.

Description

Optical module, optical device, and method for manufacturing optical module

[0001] The present disclosure relates to an optical module, an optical device, and a method for manufacturing an optical module.

[0002] An optical module has been proposed that includes an optical system that separates incident light into a first light and a second light and outputs the first light, a first sensor onto which the first light is incident, and a second sensor that has a different function from the first sensor and onto which the second light is incident (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2006-324810

[0004] The optical module disclosed herein has a branching surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and forms an image of the light transmitted by the branching surface and the light reflected by the branching surface, and includes, in order from the object side, a first optical system that includes a front lens group, an optical path branching element that includes the branching surface, and a first rear lens group that has positive refractive power and onto which the light transmitted by the branching surface is incident, and a second optical system that includes, in order from the object side, the front lens group, the optical path branching element, and a second rear lens group that has positive refractive power and onto which the light reflected by the branching surface is incident, and one of the first optical system and the second optical system includes an aperture stop on the branching surface or on the image plane side of the branching surface.

[0005] The optical module disclosed herein has a branching surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and forms an image of the light transmitted by the branching surface and the light reflected by the branching surface, and includes, in order from the object side, a first optical system that includes a front lens group, an optical path branching element that includes the branching surface, and a first rear lens group that has positive refractive power and onto which the light transmitted by the branching surface is incident, and a second optical system that includes, in order from the object side, the front lens group, the optical path branching element, and a second rear lens group that has positive refractive power and onto which the light reflected by the branching surface is incident, and the number of lenses included in the front lens group is smaller than the number of lenses included in either the first rear lens group or the second rear lens group.

[0006] The optical module disclosed herein has a branching surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and forms images of the light transmitted by the branching surface and the light reflected by the branching surface, and includes a first optical system that includes, in order from the object side, a front lens group, an optical path branching member that includes the branching surface, and a first rear lens group that has positive refractive power and onto which the light transmitted by the branching surface is incident, and a second optical system that includes, in order from the object side, the front lens group, the optical path branching member, and a second rear lens group that has positive refractive power and onto which the light reflected by the branching surface is incident, and satisfies the following conditional expression: 0.10 < Df / TL1 ≦ 0.50, where Df is the length on the optical axis from the lens surface of the front lens group that is closest to the object to the lens surface of the front lens group that is closest to the image plane, and TL1 is the length on the optical axis from the lens surface of the front lens group that is closest to the object in the first optical system to the image plane.

[0007] The optical module disclosed herein has a branching surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and forms an image of the light transmitted at the branching surface and the light reflected at the branching surface, and has, in order from the object side, a first optical system that has, in order from the object side, a front lens group, an optical path branching member that has the branching surface, and a first rear lens group that has positive refractive power and onto which the light transmitted at the branching surface is incident, and a second optical system that has, in order from the object side, the front lens group, the optical path branching member, and a second rear lens group that has positive refractive power and onto which the light reflected at the branching surface is incident, and the front lens group has negative refractive power.

[0008] The method for manufacturing an optical module disclosed herein is a method for manufacturing an optical module that has a branching surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and that forms an image of the light transmitted by the branching surface and the light reflected by the branching surface, wherein a first optical system is arranged to include, in order from the object side, a front lens group, an optical path branching member having the branching surface, and a first rear lens group that has positive refractive power and onto which the light transmitted by the branching surface is incident; a second optical system is arranged to include, in order from the object side, a front lens group, the optical path branching member, and a second rear lens group that has positive refractive power and onto which the light reflected by the branching surface is incident; and an aperture stop is arranged in one of the first optical system and the second optical system at the branching surface or on the image plane side of the branching surface.

[0009] FIG. 1 is a schematic diagram illustrating a general configuration of an optical module according to the present embodiment; FIG. 1 is a cross-sectional view of a first optical system included in the optical module according to a first embodiment; FIG. 2 is a cross-sectional view of a second optical system included in the optical module according to the first embodiment; FIG. 3 is a cross-sectional view of a second optical system included in the optical module according to the first embodiment; FIG. 4 is a cross-sectional view of a first optical system included in the optical module according to a second embodiment; FIG. 5 is a cross-sectional view of a second optical system included in the optical module according to the second embodiment; FIG. 6 is a cross-sectional view of a first optical system included in the optical module according to a third embodiment; FIG. 7 is a cross-sectional view of a first optical system included in the optical module according to the third embodiment; FIG. 8 is a cross-sectional view of a second optical system included in the optical module according to the third embodiment; FIG. 9 is a cross-sectional view of a second optical system included in the optical module according to the third embodiment; 1 is a flowchart showing an outline of a method for manufacturing an optical module according to the present embodiment.

[0010] An optical module, an optical device, and a method for manufacturing an optical module according to embodiments of the present application will be described below.

[0011] FIG. 1 is a schematic diagram illustrating the general configuration of an optical module according to this embodiment.

[0012] The optical module 1 of this embodiment has a first optical system OS1 including, in order from the object side, a front lens group GF, an optical path branching member OB having a branching surface BF, and a first rear lens group GR1 onto which light incident on the front lens group GF and the optical path branching member OB and transmitted by the branching surface BF is incident. The optical module 1 of this embodiment also has a second optical system OS2 including, in order from the object side, the front lens group GF, the optical path branching member OB, and a second rear lens group GR2 onto which light incident on the front lens group GF and the optical path branching member OB and reflected by the branching surface BF is incident.

[0013] In FIG. 1, the first optical axis X1 of the first optical system OS1 and the second optical axis X2 of the second optical system OS2 are depicted so as not to overlap with each other on the object side of the splitting surface BF for the sake of explanation.

[0014] In the optical module 1 of this embodiment, light emitted from the front lens group GF is incident on the optical path branching member OB. The optical path branching member OB is a dichroic prism having a branching surface BF that transmits either visible light or near-infrared light and reflects the other. Visible light includes, for example, the d-line (wavelength 587.6 nm) or the g-line (wavelength 435.8 nm), and near-infrared light includes, for example, the s-line (wavelength 852.1 nm). In the optical module 1 of this embodiment, the light incident from the front lens group GF is branched by the optical path branching member OB. The optical path branching member OB may be a dichroic mirror having a branching surface BF.

[0015] The optical module 1 of this embodiment has a first imaging unit IS1 with a first light receiving surface AS1 on which an imaging element composed of a CCD, CMOS, or the like is arranged. The first optical system OS1 of this embodiment forms an image on the first light receiving surface AS1 of the first imaging unit IS1 by means of the first rear lens group GR1, taking light (one of visible light and near-infrared light) that is emitted from the front lens group GF and transmitted through the branching surface BF of the optical path branching member OB. The first imaging unit IS1 outputs data corresponding to the light that has been imaged on the first light receiving surface AS1.

[0016] The optical module 1 of this embodiment has a second imaging unit IS2 with a second light receiving surface AS2 on which an imaging element composed of a CCD, CMOS, or the like is arranged. The second optical system OS2 of this embodiment forms an image on the second light receiving surface AS2 of the second imaging unit IS2 by the second rear lens group GR2, using light (the other of visible light and near-infrared light) that is emitted from the front lens group GF, reflected by the branching surface BF of the optical path branching member OB, and totally reflected by a side surface of the optical path branching member OB. The second imaging unit IS2 outputs data corresponding to the light that has been imaged on the second light receiving surface AS2.

[0017] The optical module 1 of this embodiment can appropriately image the light transmitted by the branching surface BF and the light reflected by the branching surface BF, respectively, using the first optical system OS1 and the second optical system OS2.

[0018] Of the first imaging unit IS1 and the second imaging unit IS2, data output by the imaging unit that focuses visible light is used to generate an image representing the appearance of an object. Of the first imaging unit IS1 and the second imaging unit IS2, the imaging unit that focuses visible light may have an imaging element that receives multiple colors including, for example, d-line or g-line, and output a color image representing the appearance of the object. The generated image may be used to detect the appearance of the object.

[0019] The optical module 1 of this embodiment may include a light source LS that emits light of a predetermined wavelength, such as near-infrared light (e.g., s-rays). The light source LS is an example of an illumination unit and includes a laser or the like as a light-emitting element. The optical module 1 of this embodiment irradiates an object (not shown) with light of the predetermined wavelength using the light source LS. In the optical module 1 of this embodiment, light from the object is incident on the front lens group GF.

[0020] The imaging unit that forms an image of near-infrared light, either the first imaging unit IS1 or the second imaging unit IS2, can receive light emitted from the light source LS and reflected by an object. Data output by the imaging unit that forms an image of near-infrared light, either the first imaging unit IS1 or the second imaging unit IS2, may be used to detect the distance to the object.

[0021] For example, data output by an imaging unit that forms an image using near-infrared light can be used to detect the time it takes for light emitted from the light source LS to be reflected by an object and received by the imaging unit. The detected time may be used to detect the distance to the object using a time-of-flight (TOF) method.

[0022] The light emitted from the light source LS may have a predetermined pattern, such as a stripe or a grid. In this case, the image capture unit that focuses the near-infrared light outputs data representing the distortion of the light pattern reflected by the object. The data output by the image capture unit that focuses the near-infrared light may be used to detect the distance to the object using the structured light method.

[0023] The optical module 1 of this embodiment is equipped with a light source LS that emits light used to detect the distance to an object, and thereby irradiates the light used to detect the distance to the object onto the target object, thereby enabling the distance to the object to be detected effectively using the TOF method or structured light method.

[0024] The optical module 1 of this embodiment can detect both the appearance of a target object and the distance to the object. Since the optical module 1 of this embodiment does not have parallax between the image used to detect the appearance of the object and the image used to detect the distance to the object, the calculation process for associating each pixel in the image of the object with the distance to the surface of the object corresponding to that pixel is reduced.

[0025] In the optical module 1 of this embodiment, the optical system used to detect the distance to an object preferably has a relatively small F-number and can obtain a relatively bright image. On the other hand, the optical system used to detect the appearance of an object preferably achieves high optical performance and can obtain an image in which various aberrations are appropriately corrected. It is even more preferable that the optical system used to detect the appearance of an object has a relatively small F-number and can obtain a relatively bright image.

[0026] Therefore, in the optical module 1 of this embodiment, the F-number of the optical system between the first optical system OS1 and the second optical system OS2 that is used to detect the distance to an object may be configured to be equal to or less than the F-number of the optical system between the first optical system OS1 and the second optical system OS2 that is used to detect the appearance of an object.

[0027] In the optical module 1 of this embodiment, by having such a configuration, a brighter image can be used to detect the distance to an object, and an image in which various aberrations have been appropriately corrected can be used to detect the appearance of the object.

[0028] Furthermore, it is preferable that the optical module 1 of this embodiment satisfy both of the following conditional expressions: (4) 0.20<Fno_tof / Fno_img<1.00 (5) 1.00<Fno_tof<2.00 where, Fno_tof: F-number of the optical system of the first optical system OS1 or the second optical system OS2 that is used to detect the distance to the object, and Fno_img: F-number of the optical system of the first optical system OS1 or the second optical system OS2 that is used to detect the appearance of the object.

[0029] Conditional expression (4) defines the ratio between the F-number of the optical system of the first optical system OS1 or the second optical system OS2 that is used to detect the distance to the object and the F-number of the optical system of the first optical system OS1 or the second optical system OS2 that is used to detect the appearance of the object. By satisfying conditional expression (4), the optical module 1 of this embodiment can ensure appropriate brightness in each of the first optical system OS1 and the second optical system OS2.

[0030] In the optical module 1 of this embodiment, if the value of conditional expression (4) exceeds the upper limit, it is not possible to ensure appropriate brightness in the optical system used to detect the distance to an object, either the first optical system OS1 or the second optical system OS2.

[0031] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the upper limit value of conditional expression (4) to 1.00. In order to further ensure the effect of this embodiment, it is preferable to set the upper limit value of conditional expression (4) to 0.80, 0.70, or even 0.65.

[0032] Furthermore, in the optical module 1 of this embodiment, if the value of conditional expression (4) falls below the lower limit, it is not possible to ensure appropriate brightness in the optical system used to detect the appearance of an object, either the first optical system OS1 or the second optical system OS2.

[0033] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the lower limit of conditional expression (4) to 0.20. In order to further ensure the effect of this embodiment, it is preferable to set the lower limit of conditional expression (4) to 0.30, 0.40, or even 0.55.

[0034] Conditional expression (5) defines the F-number of either the first optical system OS1 or the second optical system OS2, which is used to detect the distance to the object. By satisfying conditional expression (5), the optical module 1 of this embodiment can ensure appropriate brightness in either the first optical system OS1 or the second optical system OS2, which is used to detect the distance to the object.

[0035] In the optical module 1 of this embodiment, if the value of conditional expression (5) exceeds the upper limit, it is not possible to ensure appropriate brightness in the optical system used to detect the distance to an object, either the first optical system OS1 or the second optical system OS2.

[0036] In the optical module 1 of this embodiment, the upper limit value of conditional expression (5) is set to 2.00, thereby making it possible to further ensure the effects of this embodiment. In order to further ensure the effects of this embodiment, it is preferable to set the upper limit value of conditional expression (5) to 1.80, 1.60, or even 1.40.

[0037] Furthermore, in the optical module 1 of this embodiment, if the value of conditional expression (5) falls below the lower limit, the optical system used to detect the distance to the object, either the first optical system OS1 or the second optical system OS2, becomes too large.

[0038] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the lower limit of conditional expression (5) to 1.00. In order to further ensure the effect of this embodiment, it is preferable to set the lower limit of conditional expression (5) to 1.10, 1.15, or even 1.20.

[0039] Furthermore, in the optical module 1 of this embodiment, it is preferable that the optical system of the first optical system OS1 and the second optical system OS2 that is used to detect the appearance of an object has a cemented lens, and the optical system of the first optical system OS1 and the second optical system OS2 that is used to detect the distance of an image to an object consists of only a single lens.

[0040] In the optical module 1 of this embodiment, the optical system of the first optical system OS1 or the second optical system OS2, the image of which is used to detect the appearance of an object, includes a cemented lens, thereby making it possible to appropriately correct chromatic aberration of the image used to detect the appearance of the object. Also, in the optical module 1 of this embodiment, the optical system of the first optical system OS1 or the second optical system OS2, the image of which is used to detect the distance to the object, is configured using only a single lens, making it possible to reduce the size of the optical system.

[0041] Furthermore, in the optical module 1 of this embodiment, in order to increase the area in which both the distance to the object and the appearance of the object can be detected, it is preferable to reduce the area represented by only one of the image used to detect the distance to the object and the image used to detect the appearance of the object.

[0042] Therefore, it is preferable that the optical module 1 of this embodiment satisfies the following conditional expression (7): 0.83<θ1 / θ2<1.20 where θ1 is the total angle of view of the first optical system OS1 and θ2 is the total angle of view of the second optical system OS2.

[0043] Conditional expression (7) defines the ratio between the total angle of view of the first optical system OS1 and the total angle of view of the second optical system OS2. By satisfying conditional expression (7), the optical module 1 of this embodiment can reduce the area represented by only one of the image used to detect the appearance of an object and the image used to detect the distance to the object.

[0044] In the optical module 1 of this embodiment, if the value of conditional expression (7) exceeds the upper limit, the area represented in only one of the image used to detect the appearance of the object and the image used to detect the distance to the object becomes too large.

[0045] In the optical module 1 of this embodiment, the upper limit value of conditional expression (7) is set to 1.20, thereby making it possible to further ensure the effects of this embodiment. In order to further ensure the effects of this embodiment, it is preferable to set the upper limit value of conditional expression (7) to 1.15, 1.10, or even 1.05.

[0046] Furthermore, in the optical module 1 of this embodiment, if the value of conditional expression (7) falls below the lower limit, the area represented by only one of the image used to detect the appearance of the object and the image used to detect the distance to the object becomes too large.

[0047] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the lower limit of conditional expression (7) to 0.83. In order to further ensure the effect of this embodiment, it is preferable to set the lower limit of conditional expression (7) to 0.87, 0.91, or even 0.95.

[0048] It is also preferable that the optical module 1 of this embodiment satisfies the following conditional expression (8): 70.0°<θ1, where θ1 is the full angle of view of the first optical system OS1.

[0049] Conditional expression (8) defines the full angle of view of the first optical system OS1. By satisfying conditional expression (8), the optical module 1 of this embodiment can obtain an image representing a wide range using the first optical system OS1.

[0050] In the optical module 1 of this embodiment, if the value of conditional expression (8) falls below the lower limit, the range represented by the image obtained by the first optical system OS1 becomes too narrow.

[0051] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the lower limit of conditional expression (8) to 70.0°. In order to further ensure the effect of this embodiment, it is preferable to set the lower limit of conditional expression (8) to 75.0°, 80.0°, or even 90.0°.

[0052] In the optical module 1 of this embodiment, the first optical system OS1 may be used to detect the appearance of an object, and the second optical system OS2 may be used to detect the distance to the object. In the optical module 1 having such a configuration, the first optical system OS1, onto which light transmitted through the splitting surface BF is incident, is not affected by degradation due to reflection of the light beam caused by the surface precision of the splitting surface BF, and therefore a less degraded image can be used to detect the appearance of the object.

[0053] In the optical module 1 of this embodiment, one of the first optical system OS1 and the second optical system OS2 includes an aperture stop on the splitting surface or on the image plane side of the splitting surface.

[0054] In the optical module 1 of this embodiment, the first optical system OS1 and the second optical system OS2 may each include an aperture stop on the splitting surface BF or on the image plane side of the splitting surface BF.

[0055] The optical module 1 of this embodiment includes an aperture stop, which allows the first optical system OS1 or the second optical system OS2 to have appropriate optical performance. Furthermore, by positioning the aperture stop on the splitting surface BF or closer to the image plane than the splitting surface BF, peripheral light beams in the light incident on the splitting surface BF are not restricted, and the attenuation of the peripheral light beams relative to the central light beam can be reduced.

[0056] In the optical module 1 of this embodiment, the effect of this embodiment can be further ensured by arranging an aperture stop on the image plane side of at least one lens component arranged on the image plane side of the optical path branching member OB in the first optical system OS1 and / or the second optical system OS2. Note that in this specification, the term "lens component" refers to a single lens or a cemented lens formed by cementing together multiple lenses.

[0057] In the optical module 1 of this embodiment, the number of lenses included in the front lens group GF is smaller than the number of lenses included in either the first rear lens group GR1 or the second rear lens group GR2.

[0058] In the optical module 1 of this embodiment, by making the number of lenses included in the front lens group GF less than the number of lenses included in either the first rear lens group GR1 or the second rear lens group GR2, the optical module 1 can be made smaller and a first optical system OS1 or a second optical system OS2 with appropriate optical performance can be obtained.

[0059] Furthermore, in the optical module 1 of this embodiment, the number of lenses included in the front lens group GF may be less than the number of lenses included in the other of the first rear lens group GR1 and the second rear lens group GR2 (the other of the first rear lens group GR1 and the second rear lens group GR2 that has fewer lenses than the number of lenses in the front lens group GF).

[0060] In the optical module 1 of this embodiment, by making the number of lenses included in the front lens group GF less than the number of lenses included in the other of the first rear lens group GR1 and the second rear lens group GR2, the optical module 1 can be made smaller and a first optical system OS1 and a second optical system OS2 with appropriate optical performance can be obtained.

[0061] The optical module 1 of this embodiment satisfies the following conditional expression (2): 0.10<Df / TL1≦0.50, where Df is the length on the optical axis from the lens surface of the front lens group GF closest to the object to the lens surface of the front lens group GF closest to the image plane, and TL1 is the length on the optical axis from the lens surface of the front lens group GF closest to the object in the first optical system OS1 to the image plane.

[0062] Conditional expression (2) defines the ratio between the axial length from the lens surface of the front lens group GF closest to the object to the lens surface of the front lens group closest to the image plane in the first optical system OS1, and the axial length from the lens surface of the front lens group GF closest to the object to the image plane in the first optical system OS1. In the optical module 1 of this embodiment, satisfying conditional expression (2) enables the optical module 1 to be made compact, while enabling an optical design suitable for each of the light beams branched by the branching surface BF to be performed.

[0063] In the optical module 1 of this embodiment, if the value of conditional expression (2) exceeds the upper limit, it becomes difficult to carry out an optical design suitable for each of the branched light beams.

[0064] In the optical module 1 of this embodiment, the upper limit value of conditional expression (2) is set to 0.50, thereby making it possible to further ensure the effects of this embodiment. In order to further ensure the effects of this embodiment, it is preferable to set the upper limit value of conditional expression (2) to 0.40, 0.37, or even 0.33.

[0065] Furthermore, in the optical module 1 of this embodiment, if the value of conditional expression (2) falls below the lower limit, the number of lenses required for an optical design suited to each of the split light beams increases, and the optical module 1 becomes larger.

[0066] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the lower limit of conditional expression (2) to 0.10. In order to further ensure the effect of this embodiment, it is preferable to set the lower limit of conditional expression (2) to 0.15, 0.17, or even 0.19.

[0067] In the optical module 1 of this embodiment, the front lens group GF has negative refractive power.

[0068] The optical module 1 of this embodiment can be made small in size by having the front lens group have negative refractive power.

[0069] Furthermore, it is preferable that the optical module 1 of this embodiment satisfy the following conditional expression: 0.20<Dst_im / TL1<0.50 (1) where Dst_im is the length from the aperture stop ST1 in the first optical system OS1 to the image plane, and TL1 is the length on the optical axis from the lens surface of the front lens group GF in the first optical system OS1 that is closest to the object to the image plane.

[0070] Conditional expression (1) defines the ratio between the length from the aperture stop ST1 in the first optical system OS1 to the image plane and the length on the optical axis from the lens surface of the front lens group GF in the first optical system OS1 that is closest to the object to the image plane. By satisfying conditional expression (1), the optical module 1 of this embodiment can position the aperture stop ST1 in the first optical system OS1 on the image plane side of the first optical system OS1, thereby shortening the overall length.

[0071] In the optical module 1 of this embodiment, if the value of conditional expression (1) exceeds the upper limit, the overall length of the first optical system OS1 becomes too long, and as a result, the overall length of the optical module 1 becomes too long.

[0072] In the optical module 1 of this embodiment, the upper limit value of conditional expression (1) is set to 0.50, thereby making it possible to further ensure the effects of this embodiment. In order to further ensure the effects of this embodiment, it is preferable to set the upper limit value of conditional expression (1) to 0.47, 0.43, or even 0.40.

[0073] Furthermore, in the optical module 1 of this embodiment, if the value of conditional expression (1) falls below the lower limit, it becomes difficult to correct various aberrations in the first optical system OS1.

[0074] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the lower limit of conditional expression (1) to 0.20. In order to further ensure the effect of this embodiment, it is preferable to set the lower limit of conditional expression (1) to 0.25, 0.28, or even 0.32.

[0075] It is also preferable that the optical module 1 of this embodiment satisfies the following conditional expression (3): 0.30<f1R / f2R<3.33 where f1R is the focal length of the first rear lens group GR1 and f2R is the focal length of the second rear lens group GR2.

[0076] Conditional expression (3) defines the ratio between the focal length of the first rear lens group GR1 and the focal length of the second rear lens group GR2. By satisfying conditional expression (3), the optical module 1 of this embodiment can prevent the overall lengths of the first optical system OS1 and the second optical system OS2 from becoming too long.

[0077] In the optical module 1 of this embodiment, if the value of conditional expression (3) exceeds the upper limit, the number of lenses in the first rear lens group GR1 increases, and the overall length of the first optical system OS1 becomes too long.

[0078] In the optical module 1 of this embodiment, the upper limit value of conditional expression (3) is set to 3.33, thereby making it possible to further ensure the effects of this embodiment. In order to further ensure the effects of this embodiment, it is preferable to set the upper limit value of conditional expression (3) to 2.85, 2.00, or even 1.67.

[0079] Furthermore, in the optical module 1 of this embodiment, if the value of conditional expression (3) is below the lower limit, the number of lenses in the second rear lens group GR2 increases, and the overall length of the second optical system OS2 becomes too long.

[0080] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the lower limit of conditional expression (3) to 0.30. In order to further ensure the effect of this embodiment, it is preferable to set the lower limit of conditional expression (3) to 0.35, 0.50, or even 0.60.

[0081] In the optical module 1 of this embodiment, of the light reflected by the splitting surface BF of the optical path splitting member OB, at least the light on the second optical axis X2 is totally reflected by the total reflection surface TRF of the optical path splitting member OB. By providing the total reflection surface TRF in the optical module 1 of this embodiment, the angle of incidence of the incident light on the splitting surface can be made small, and the difficulty of manufacturing a splitting surface with predetermined performance can be reduced.

[0082] Furthermore, in the optical module 1 of this embodiment, the total internal reflection surface TRF can be the same surface as the surface of the prism onto which light that has passed through the front lens group GF is incident. In the optical module of this embodiment, by making the total internal reflection surface TRF the same surface as the surface of the prism onto which light that has passed through the front lens group GF is incident, the structure of the prism does not become complicated and can be manufactured relatively easily.

[0083] Furthermore, it is preferable that the optical module 1 of this embodiment satisfy the following conditional expression (6): 1.00<Pr1 / f1<6.00, where Pr1 is the length on the optical axis from the object-side surface of the optical path branching member OB in the first optical system OS1 to the image-plane-side surface of the optical path branching member OB, and f1 is the focal length of the first optical system OS1.

[0084] Conditional expression (6) defines the ratio of the length on the optical axis from the object-side surface of the optical path branching member OB in the first optical system OS1 to the image-plane-side surface of the optical path branching member OB to the focal length of the first optical system OS1. By satisfying conditional expression (6), the optical module 1 of this embodiment can appropriately brighten the image obtained by the second optical system OS2 while reducing the size of the optical module 1.

[0085] In the optical module 1 of this embodiment, if the value of conditional expression (6) exceeds the upper limit, the overall length becomes long relative to the focal length, and the optical module 1 becomes large.

[0086] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the upper limit of conditional expression (6) to 6.00. In order to further ensure the effect of this embodiment, it is preferable to set the upper limit of conditional expression (6) to 5.50, 5.00, or even 4.50.

[0087] Furthermore, in the optical module 1 of this embodiment, if the value of conditional expression (6) falls below the lower limit, the peripheral light flux is limited in the second optical system OS2, and the brightness of the formed image becomes insufficient.

[0088] In the optical module 1 of this embodiment, the effect of this embodiment can be more reliably achieved by setting the lower limit of conditional expression (6) to 1.00. In order to further ensure the effect of this embodiment, it is preferable to set the lower limit of conditional expression (6) to 1.50, 1.80, or even 2.20.

[0089] In the optical module 1 of this embodiment, it is preferable that each of the first rear lens group GR1 and the second rear lens group GR2 is made up of a plurality of lenses.

[0090] In the optical module 1 of this embodiment, the front lens group GF preferably has negative refractive power, and the first rear lens group GR1 and the second rear lens group GR2 preferably have positive refractive power. By ensuring a distance for disposing the optical path branching member OB between the front lens group GF, which has negative refractive power, and the first rear lens group GR1, which has positive refractive power, the first optical system OS1 can form an image with a wide angle of view while appropriately correcting various aberrations. The same applies to the second optical system OS2.

[0091] With the optical module 1 of this embodiment having such a configuration, it is possible to appropriately correct various aberrations in each of the first optical system OS1 and the second optical system OS2.

[0092] With the above configuration, it is possible to realize an optical module that appropriately forms an image from each of the light transmitted by the splitting surface and the light reflected by the splitting surface out of the incident light.

[0093] The optical device of this embodiment has the optical module 1 configured as described above, and detects the appearance of an object represented in an image formed by light through the optical module 1 and the distance to the object.

[0094] By having such a configuration, the optical device of this embodiment can appropriately image each of the light that is transmitted through the branching surface and the light that is reflected by the branching surface out of the incident light, and can detect the appearance of the object and the distance to the object represented in each image.

[0095] The optical device of this embodiment also includes the optical module 1 having the above-described configuration, a detection unit that detects the appearance of an object represented in an image formed by light by the optical module 1 and the distance to the object, a model generation unit that generates shape model information indicating the shape of the object based on the detected distance to the object, and a texture generation unit that generates texture information indicating the appearance of the object based on the detected appearance of the object and associates the generated texture information with the shape model information.

[0096] By having such a configuration, the optical device of this embodiment can appropriately image each of the incident light that is transmitted through the branching surface and the light that is reflected by the branching surface, generate shape model information that indicates the shape of the object and texture information that indicates the appearance of the object, and associate the texture information with the shape model information.

[0097] The manufacturing method for the optical module of this embodiment is a manufacturing method for an optical module 1 that has a branching surface BF that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and that respectively forms images of the light transmitted by the branching surface BF and the light reflected by the branching surface BF, wherein a first optical system OS1 is arranged to have, in order from the object side, a front lens group GF, an optical path branching member OB having the branching surface BF, and a first rear lens group GR1 that has positive refractive power and is incident on the light transmitted by the branching surface BF, a second optical system OS2 is arranged to have, in order from the object side, a front lens group GF, the optical path branching member OB, and a second rear lens group GR2 that has positive refractive power and is incident on the light reflected by the branching surface BF, and an aperture stop is arranged on the image plane side of the branching surface BF in one of the first optical system OS1 and the second optical system OS2.

[0098] By using such a method for manufacturing an optical module, it is possible to manufacture an optical module 1 that appropriately forms an image from each of the light transmitted through the splitting surface and the light reflected by the splitting surface out of the incident light.

[0099] Numerical Examples Hereinafter, examples of the present invention will be described with reference to the drawings.

[0100] In the optical module 1 of the first embodiment, the splitting surface BF transmits visible light and reflects near-infrared light. Therefore, in the optical module 1 of the first embodiment, the first optical system OS1 is an optical system that forms an image of visible light, and the second optical system OS2 is an optical system that forms an image of near-infrared light.

[0101] FIG. 2 is a cross-sectional view of the first optical system OS1 included in the optical module 1 of the first embodiment.

[0102] The first optical system OS1 of this embodiment has, in order from the object side, a meniscus negative lens L1 with a convex surface facing the object side, a biconcave negative lens L2, a meniscus positive lens L3 with a concave surface facing the object side, an optical path branching member OB, a meniscus positive lens L11 with a convex surface facing the object side, an aperture stop ST1, a meniscus positive lens L12 with a convex surface facing the object side, a cemented negative lens consisting of a biconvex positive lens L13 and a biconcave negative lens L14, a meniscus positive lens L15 with a convex surface facing the object side, and a meniscus positive lens L16 with a convex surface facing the object side.

[0103] A first light receiving surface AS1 of a first imaging unit IS1 having an imaging element configured by a CCD, CMOS, or the like is arranged on the image plane I1.

[0104] A filter FL1 is disposed between the image plane I1 and the positive lens L16, which is disposed closest to the image plane I1.

[0105] In the first optical system OS1 of this embodiment, the negative lens L1, negative lens L2, and positive lens L3 are included in the front lens group GF, and the positive lens L11, aperture stop ST1, positive lens L12, a cemented negative lens formed by a positive lens L13 and a negative lens L14, positive lens L15, and positive lens L16 are included in the first rear lens group GR1.

[0106] Table 1-1 below lists the specifications of the first optical system OS1 of this embodiment. In the [Lens specifications] in Table 1-1, m indicates the order of the optical surface counted from the object side, r indicates the radius of curvature, d indicates the surface spacing, n(d) indicates the refractive index for the d-line, and vd indicates the Abbe number for the d-line. A radius of curvature of r=∞ indicates a flat surface. Additionally, in the [Lens specifications], an optical surface marked with an "*" indicates that it is an aspherical surface.

[0107] In [Aspherical Data], m indicates the optical surface corresponding to the aspherical data, K indicates the conic constant, and A4 to A10 indicate the aspherical coefficients.

[0108] The aspherical surface is expressed by the following formula (a), where y is the height in the direction perpendicular to the optical axis, S(y) is the distance (amount of sag) along the optical axis from the tangent plane of the vertex of each aspherical surface at height y to each aspherical surface, r is the radius of curvature (paraxial radius of curvature) of the reference spherical surface, K is the conic constant, and An is the n-th order aspherical coefficient. In each example, the second order aspherical coefficient A2 is 0. Also, "En" is expressed as "×10 -n " indicates.

[0109] (a) S(y) = (y 2 / r) / 1 + (1-K×y 2 / r 2 ) 1 / 2 + A4×y 4 + A6×y 6 + A8×y 8 + A10×y 10

[0110] In the [Overall Specifications] of Table 1-1, Fno is the F-number of the first optical system OS1, f is the focal length of the entire first optical system OS1, TL is the distance from the lens surface closest to the object to the image plane, Y is the image height, and 2ω is the total angle of view (degrees). Note that these values ​​listed in [Overall Specifications] are values ​​for the d-line.

[0111] The focal length f, radius of curvature r, and other length values ​​listed in Table 1-1 are in mm. However, this is not limited to this, as the same optical performance can be obtained even when the optical system is proportionally enlarged or reduced.

[0112] The symbols in Table 1-1 described above are also used in the second optical system OS2 of this embodiment and in tables of other embodiments, which will be described later.

[0113] (Table 1-1) [Lens specifications] m r d n(d) νd 1) 23.24716 2.500 1.618 63.34 2) 8.85754 6.000 3) -62.73425 1.300 1.618 63.34 4) 10.07820 2.940 5) -62.37902 5.500 1.755 27.57 6) -30.02650 0.800 7) ∞ 11.000 1.517 63.88 (Optical path branching member OB) 8) ∞ 0.150 9) 18.88785 5.650 1.700 48.10 10) 300.00000 1.540 11> ∞ 1.550 (Aperture stop ST1) 12) 14.36704 2.600 1.697 55.52 13) 313.89814 0.150 14) 15.11805 2.200 1.519 69.89 15) -25.38622 0.400 1.755 27.57 16) 9.06631 0.930 17) 9.42227 2.400 1.623 58.12 18) 42.81721 1.830 *19) 11.33584 4.500 1.623 58.12 *20) 23.57318 4.660 21) ∞ 0.500 1.517 63.88 (Filter FL1) 22) ∞ 0.359 [Aspheric data] m K A4 A6 A8 A10 19) -1.1497 -7.48E-05 -1.27E-06 -8.15E-08 7.15E-10 20) -4.4220 8.96E-05 -2.30E-06 -3.03E-08 3.23E-10 [Overall specifications] Fno 2.00 f 4.99 TL 59.46 Y 4.01 2ω 92.00

[0114] In the optical path branching member OB of this embodiment, which is a dichroic prism, the seventh surface corresponds to the object side surface, and the eighth surface corresponds to the image plane side surface.

[0115] FIG. 3 is a diagram showing various aberrations of the first optical system OS1 included in the optical module 1 of the first embodiment.

[0116] In each aberration diagram, the spherical aberration diagram (LONGITUDINAL SPHERICAL ABERRATION) shows the ratio to the maximum aperture, the astigmatism diagram (ASTIGMATIC FIELD CURVES) and distortion diagram (DISTORTION) show values ​​for half the angle of view, and the coma diagram shows the ratio to the maximum image height. Each aberration diagram shows values ​​for the d-line and g-line, respectively. In the astigmatism diagram, S indicates the sagittal image plane, and T indicates the meridional image plane. The same symbols as those used in the aberration diagrams of this embodiment are used in the aberration diagrams of other embodiments described below.

[0117] From each aberration diagram, it can be seen that the first optical system OS1 of this embodiment appropriately corrects various aberrations and has high optical performance for the d-line and g-line.

[0118] FIG. 4 is a cross-sectional view of the second optical system OS2 included in the optical module 1 of the first embodiment.

[0119] The second optical system OS2 of this embodiment has, in order from the object side, a meniscus negative lens L1 with a convex surface facing the object side, a biconcave negative lens L2, a meniscus positive lens L3 with a concave surface facing the object side, an optical path branching member OB, a biconvex positive lens L21, an aperture stop ST2, a meniscus positive lens L22 with a convex surface facing the object side, a meniscus negative lens L23 with a concave surface facing the object side, and a biconvex positive lens L24.

[0120] A second light receiving surface AS2 of a second imaging unit IS2 having an imaging element configured by a CCD, CMOS, or the like is disposed on the image plane I2.

[0121] A filter FL2 is disposed between the positive lens L24, which is disposed closest to the image plane I2, and the image plane I2.

[0122] In the second optical system OS2 of this embodiment, the negative lens L1, the negative lens L2, and the positive lens L3 are included in the front lens group GF, and the positive lens L21, the aperture stop ST2, the positive lens L22, the negative lens L23, and the positive lens L24 are included in the second rear lens group GR2.

[0123] Table 1-2 below lists the specifications of the second optical system OS2 of this embodiment. In the [Lens specifications] section of Table 1-2, n(s) indicates the refractive index for the s-line. This symbol will also be used in the tables of other embodiments described later.

[0124] (Table 1-2) [Lens specifications] m r d n(d) νd ns 1) 23.24716 2.500 1.618 63.34 1.610 2) 8.85754 6.000 3) -62.73425 1.300 1.618 63.34 1.610 4) 10.07820 2.940 5) -62.37902 5.500 1.755 27.57 1.735 6) -30.02650 0.800 7) ∞ 32.500 1.517 63.88 1.510 (Optical path branching member OB) 8) ∞ 0.230 9) 15.44687 2.850 1.835 42.73 1.819 10) -300.00000 1.400 11> ∞ 1.650 (Aperture stop ST2) 12) 10.79653 2.850 1.835 42.73 1.819 13) 350.00000 0.920 14) -15.64213 0.500 1.835 42.73 1.819 15) -83.64620 1.190 *16) 300.00000 4.150 1.835 42.73 1.819 *17) -25.21347 3.490 18) ∞ 0.210 1.517 63.88 1.510 (Filter FL2) 19) ∞ 0.343 [Aspherical data] m K A4 A6 A8 A10 16) 9.2225 7.80E-05 2.38E-06 1.06E-06 -3.67E-08 17) -2.9888 4.80E-04 -1.15E-05 3.76E-06 -1.49E-07 [Overall specifications] Fno 1.18 f 2.81 TL 71.32 Y 2.29 2ω 92.00

[0125] 5A to 5C are diagrams showing various aberrations of the second optical system OS2 included in the optical module 1 of Example 1. Each aberration diagram shows values ​​for the s-line.

[0126] From each aberration diagram, it can be seen that the second optical system OS2 of this embodiment appropriately corrects various aberrations and has high optical performance for the s-line.

[0127] Second Example In the optical module 1 of the second example, the splitting surface BF transmits near-infrared light and reflects visible light. Therefore, in the optical module 1 of the second example, the first optical system OS1 is an optical system that forms an image of near-infrared light, and the second optical system OS2 is an optical system that forms an image of visible light.

[0128] FIG. 6 is a cross-sectional view of the first optical system OS1 included in the optical module 1 of the second embodiment.

[0129] The first optical system OS1 of this embodiment has, in order from the object side, a meniscus-shaped negative lens L1 with a convex surface facing the object side, a biconcave negative lens L2, a meniscus-shaped positive lens L3 with a convex surface facing the object side, an optical path branching member OB, a meniscus-shaped negative lens L11 with a convex surface facing the object side, an aperture stop ST1, a biconvex positive lens L12, a meniscus-shaped positive lens L13 with a convex surface facing the object side, and a biconvex positive lens L14.

[0130] A first light receiving surface AS1 of a first imaging unit IS1 having an imaging element configured by a CCD, CMOS, or the like is arranged on the image plane I1.

[0131] In the first optical system OS1 of this embodiment, the negative lens L1, negative lens L2, and positive lens L3 are included in the front lens group GF, and the negative lens L11, aperture stop ST1, positive lens L12, positive lens L13, and positive lens L14 are included in the first rear lens group GR1.

[0132] Table 2-1 below lists the specifications of the first optical system OS1 of this embodiment.

[0133] (Table 2-1) [Lens specifications] m r d n(d) νd ns 1) 29.68897 1.200 1.640 60.20 1.631 2) 9.70092 5.000 3) -195.75734 1.200 1.618 63.34 1.610 4) 11.92145 1.550 5) 28.18828 2.000 1.755 27.57 1.735 6) 43.38751 1.000 7) ∞ 12.000 1.517 63.88 1.510 (Optical path branching member OB) 8) ∞ 0.500 9) 16.64118 0.350 1.532 48.78 1.523 10) 9.69527 11.748 11> ∞ 0.100 (Aperture stop ST1) 12) 16.58651 3.000 1.755 27.57 1.735 13) -531.70077 4.273 14) 10.44070 5.497 1.755 27.57 1.735 15) 14.92879 0.647 *16) 13.31421 5.500 1.774 47.18 1.760 17) -128.00260 4.854 [Aspherical data] m K A4 A6 A8 A10 16) -4.0120 -1.07E-04 -5.73E-06 1.74E-08 6.04E-10 [Overall specifications] Fno 1.20 f 2.77 TL 60.42 Y 2.20 2ω 92.00

[0134] In the optical path branching member OB of this embodiment, which is a dichroic prism, the seventh surface corresponds to the object side surface, and the eighth surface corresponds to the image plane side surface.

[0135] 7A and 7B are diagrams showing various aberrations of the first optical system OS1 included in the optical module 1 of Example 2. Each aberration diagram shows values ​​for the s-line.

[0136] From each aberration diagram, it can be seen that the first optical system OS1 of this embodiment appropriately corrects various aberrations and has high optical performance for the s-line.

[0137] FIG. 8 is a cross-sectional view of the second optical system OS2 included in the optical module 1 of the second embodiment.

[0138] The second optical system OS2 of this embodiment has, in order from the object side, a meniscus negative lens L1 with a convex surface facing the object side, a biconcave negative lens L2, a meniscus positive lens L3 with a convex surface facing the object side, an optical path branching member OB, a meniscus positive lens L21 with a convex surface facing the object side, an aperture stop ST2, a meniscus negative lens L22 with a convex surface facing the object side, a cemented negative lens consisting of a biconvex positive lens L23 and a biconcave negative lens L24, a meniscus positive lens L25 with a convex surface facing the object side, and a meniscus positive lens L26 with a convex surface facing the object side.

[0139] A second light receiving surface AS2 of a second imaging unit IS2 having an imaging element configured by a CCD, CMOS, or the like is disposed on the image plane I2.

[0140] A filter FL2 is disposed between the positive lens L26, which is disposed closest to the image plane I2, and the image plane I2.

[0141] In the second optical system OS2 of this embodiment, the negative lens L1, the negative lens L2, and the positive lens L3 are included in the front lens group GF, and the positive lens L21, the aperture stop ST2, the negative lens L22, the cemented negative lens formed by the negative lens L23 and the positive lens L24, the positive lens L25, and the positive lens L26 are included in the second rear lens group GR2.

[0142] Table 2-2 below lists the values ​​of the specifications of the second optical system OS2 of this embodiment.

[0143] (Table 2-2) [Lens specifications] m r d n(d) νd 1) 29.68900 1.200 1.640 60.19 2) 9.70090 5.000 3) -195.75730 1.200 1.618 63.34 4) 11.92140 1.550 5) 28.18830 2.000 1.755 27.57 6) 43.38750 1.000 7) ∞ 32.500 1.517 63.88 (Optical path branching member OB) 8) ∞ 0.500 9) 12.82210 2.620 1.700 48.10 10) 302.64820 3.760 11> ∞ 0.100 (Aperture stop ST2) 12) 30.12150 0.955 1.651 56.24 13) 26.67870 0.100 14) 10.81720 2.710 1.519 69.89 15) -14.47040 0.350 1.755 27.57 16) 16.24750 0.100 17) 9.11660 1.150 1.620 60.24 18) 10.15080 1.039 *19) 14.74820 5.500 1.620 60.24 *20) 270.84350 1.000 21) ∞ 0.300 1.517 63.88 (Filter FL2) 22) ∞ 7.217 [Aspheric data] m K A4 A6 A8 A10 19) -3.2435 -2.20E-04 -3.59E-06 3.52E-09 2.17E-10 20) 11.0000 -4.40E-05 -1.45E-06 4.57E-08 -2.20E-10 [Overall specifications] Fno 2.10 f 5.03 TL 71.85 Y 4.02 2ω 92.00

[0144] 9A to 9C are diagrams showing various aberrations of the second optical system OS2 included in the optical module 1 of Example 2. Each aberration diagram shows values ​​for the d-line and the g-line.

[0145] From each aberration diagram, it can be seen that the second optical system OS2 of this embodiment appropriately corrects various aberrations and has high optical performance for the d-line and g-line.

[0146] In the optical module 1 of the third embodiment, the splitting surface BF transmits visible light and reflects near-infrared light. Therefore, in the optical module 1 of the third embodiment, the first optical system OS1 is an optical system that forms an image of visible light, and the second optical system OS2 is an optical system that forms an image of near-infrared light.

[0147] FIG. 10 is a cross-sectional view of the first optical system OS1 included in the optical module 1 of the third embodiment.

[0148] The first optical system OS1 of this embodiment has, in order from the object side, a meniscus negative lens L1 with a convex surface facing the object side, a biconcave negative lens L2, a meniscus positive lens L3 with a concave surface facing the object side, an optical path branching member OB, a meniscus positive lens L11 with a convex surface facing the object side, an aperture stop ST1, a meniscus positive lens L12 with a convex surface facing the object side, a cemented negative lens consisting of a biconvex positive lens L13 and a biconcave negative lens L14, a meniscus positive lens L15 with a convex surface facing the object side, and a meniscus positive lens L16 with a convex surface facing the object side.

[0149] A first light receiving surface AS1 of a first imaging unit IS1 having an imaging element configured by a CCD, CMOS, or the like is arranged on the image plane I1.

[0150] A filter FL1 is disposed between the image plane I1 and the positive lens L16, which is disposed closest to the image plane I1.

[0151] In the first optical system OS1 of this embodiment, the negative lens L1, negative lens L2, and positive lens L3 are included in the front lens group GF, and the positive lens L11, aperture stop ST1, positive lens L12, a cemented negative lens formed by a positive lens L13 and a negative lens L14, positive lens L15, and positive lens L16 are included in the first rear lens group GR1.

[0152] Table 3-1 below lists the values ​​of the specifications of the first optical system OS1 of this embodiment.

[0153] (Table 3-1) [Lens specifications] m r d n(d) νd 1) 22.65975 2.000 1.603 60.69 2) 8.58484 6.013 3) -46.67377 0.800 1.519 69.89 4) 10.08192 3.049 5) -69.22039 2.313 1.755 27.57 6) -40.41329 0.988 7) ∞ 17.000 1.517 63.88 (Optical path branching member OB) 8) ∞ 0.384 9) 15.15381 2.574 1.720 50.27 10) 516.88017 4.098 11> ∞ 0.100 (Aperture stop ST1) 12) 15.83971 2.165 1.651 56.24 13) 42.97328 0.100 14) 12.34848 2.119 1.519 69.89 15) -21.04824 0.350 1.755 27.57 16) 10.90829 0.100 17) 9.48441 2.289 1.620 60.24 18) 23.82029 1.297 *19) 12.79368 5.503 1.620 60.24 *20) 25.72131 1.000 21) ∞ 0.300 1.517 63.88 (Filter FL1) 22) ∞ 3.960 [Aspheric data] m K A4 A6 A8 A10 19) -2.0024 -1.76E-04 -2.50E-06 -1.86E-08 3.06E-10 20) 11.0000 8.87E-05 -1.45E-06 1.92E-08 4.13E-09 [Overall specifications] Fno 2.00 f 4.93 TL 58.50 Y 4.01 2ω 92.00

[0154] In the optical path branching member OB of this embodiment, which is a dichroic prism, the seventh surface corresponds to the object side surface, and the eighth surface corresponds to the image plane side surface.

[0155] 11A to 11C are diagrams showing various aberrations of the first optical system OS1 included in the optical module 1 of Example 3. Each aberration diagram shows values ​​for the d-line and the g-line.

[0156] From each aberration diagram, it can be seen that the first optical system OS1 of this embodiment appropriately corrects various aberrations and has high optical performance for the d-line and g-line.

[0157] FIG. 12 is a cross-sectional view of the second optical system OS2 included in the optical module 1 of the third embodiment.

[0158] The second optical system OS2 of this embodiment has, in order from the object side, a meniscus-shaped negative lens L1 with a convex surface facing the object side, a biconcave negative lens L2, a meniscus-shaped positive lens L3 with a concave surface facing the object side, an optical path branching member OB, a biconvex positive lens L21, an aperture stop ST2, a meniscus-shaped positive lens L22 with a convex surface facing the object side, a meniscus-shaped positive lens L23 with a convex surface facing the object side, a meniscus-shaped positive lens L24 with a convex surface facing the object side, and a meniscus-shaped positive lens L25 with a concave surface facing the object side.

[0159] A second light receiving surface AS2 of a second imaging unit IS2 having an imaging element configured by a CCD, CMOS, or the like is disposed on the image plane I2.

[0160] A filter FL2 is disposed between the image plane I2 and the positive lens L25 disposed closest to the image plane I2.

[0161] In the second optical system OS2 of this embodiment, the negative lens L1, the negative lens L2, and the positive lens L3 are included in the front lens group GF, and the positive lens L21, the aperture stop ST2, the positive lens L22, the positive lens L23, the positive lens L24, and the positive lens L25 are included in the second rear lens group GR2.

[0162] Table 3-2 below lists the specifications of the second optical system OS2 of this embodiment.

[0163] (Table 3-2) [Lens specifications] m r d n(d) νd ns 1) 22.65975 2.000 1.603 60.69 1.595 2) 8.58484 6.013 3) -46.67377 0.800 1.519 69.89 1.512 4) 10.08192 3.049 5) -69.22039 2.313 1.755 27.57 1.735 6) -40.41329 0.988 7) ∞ 47.000 1.517 63.88 1.510 (Optical path branching member OB) 8) ∞ 1.805 9) 33.91430 3.017 1.720 50.27 1.708 10) -66.06093 0.100 11) ∞ 0.100 (Aperture stop ST2) 12) 26.49772 2.147 1.623 58.12 1.614 13) 74.01188 0.100 14) 19.60218 2.271 1.593 67.90 1.586 15) 46.09410 0.100 16) 13.36196 2.584 1.487 70.31 1.481 17) 29.13116 4.967 *18) -19.16636 5.496 1.487 70.31 1.481 *19) -9.49217 0.182 20) ∞ 0.300 1.517 63.88 1.510 (Filter FL2) 21) ∞ 3.000 [Aspheric data] m K A4 A6 A8 A10 18) -2.2395 -3.29E-04 3.25E-06 1.17E-07 -4.08E-09 19) 0.3196 -1.85E-05 1.28E-05 -1.34E-07 -8.44E-09 [Overall specifications] Fno 1.20 f 2.93 TL 88.33 Y 2.29 2ω 92.00

[0164] 13A to 13C are diagrams showing various aberrations of the second optical system OS2 included in the optical module 1 of Example 3. Each aberration diagram shows values ​​for the s-line.

[0165] From each aberration diagram, it can be seen that the second optical system OS2 of this embodiment appropriately corrects various aberrations and has high optical performance for the s-line.

[0166] According to each of the above embodiments, it is possible to realize an optical module that appropriately forms an image from each of the light transmitted through the splitting surface and the light reflected by the splitting surface out of the incident light.

[0167] The values ​​corresponding to the conditional expressions in each example are shown below.

[0168] Dst_im is the length from the aperture stop ST1 in the first optical system OS1 to the image plane I1, and TL1 is the length on the optical axis from the lens surface of the front lens group GF closest to the object in the first optical system OS1 to the image plane I1. Df is the length on the optical axis from the lens surface of the front lens group GF closest to the object to the lens surface of the front lens group GF closest to the image plane. f1R is the focal length of the first rear lens group GR1, and f2R is the focal length of the second rear lens group GR2. Fno_tof is the F-number of the optical system of the first optical system OS1 or the second optical system OS2 used to detect the distance to the object, and Fno_img is the F-number of the optical system of the first optical system OS1 or the second optical system OS2 used to detect the appearance of the object. Pr1 is the length on the optical axis from the surface of the optical path branching member OB on the object side in the first optical system OS1 to the surface of the optical path branching member OB on the image plane side, and f1 is the focal length of the first optical system OS1. θ1 is the total angle of view (degrees) of the first optical system OS1, and θ2 is the total angle of view (degrees) of the second optical system OS2.

[0169] The values ​​described in the [Conditional Expression Corresponding Values] are values ​​for the d-line.

[0170] [Values ​​corresponding to conditional expressions] Example Conditional Expression 1st 2nd 3rd (1) Dst_im / TL1 0.371 0.395 0.330 (2) Df / TL1 0.307 0.181 0.242 (3) f1R / f2R 1.159 0.640 0.805 (4) Fno_tof / Fno_img 0.590 0.571 0.600 (5) Fno_tof 1.180 1.200 1.200 (6) Pr1 / f1 2.206 4.338 3.449 (7) θ1 / θ2 1.000 1.000 1.000 (8) θ1 92.000 92.000 92.000

[0171] The above examples are merely illustrative of the present invention, and the present invention is not limited to these.

[0172] Next, an optical device including the optical module 1 of this embodiment will be described with reference to Fig. 14. Fig. 14 is a schematic diagram of an optical device 10 including the optical module 1 of this embodiment.

[0173] The optical device 10 includes the optical module 1 according to the first embodiment and an information processing device 2 .

[0174] The light source LS of the optical module 1 emits light containing light of a predetermined wavelength (for example, s-ray) that is imaged by the optical system used to detect the distance to an object, either the first optical system OS1 or the second optical system OS2.

[0175] In the optical device 10, light including light of a predetermined wavelength emitted from a light source LS and reflected by an object (target) (not shown) is imaged by a first optical system OS1 and a second optical system OS2 on a first light receiving surface AS1 of a first image capturing unit IS1 and a second light receiving surface AS2 of a second image capturing unit IS2, respectively. The image capturing elements of the first image capturing unit IS1 and the second image capturing unit IS2 convert the light from the target into data.

[0176] The information processing device 2 includes a communication interface 21 , a memory 22 , and a processor 23 .

[0177] The communication interface 21 has a communication circuit for communicatively connecting the optical module 1 to the information processing device 2. The communication interface 21 outputs data supplied from the processor 23 to the optical module 1. The communication interface 21 also supplies data received from the optical module 1 to the processor 23.

[0178] The memory 22 is an example of a storage unit and includes a volatile semiconductor memory and a non-volatile semiconductor memory. The memory 22 stores various data used in processing by the processor 23, such as the angle of view of each of the first optical system OS1 and the second optical system OS2 of the optical module 1, and the number of pixels in the horizontal and vertical directions in the data output from each of the first imaging unit IS1 and the second imaging unit IS2 of the optical module 1. The memory 22 also stores various application programs, such as a detection program for executing a detection process.

[0179] The processor 23 is an example of a control unit and includes one or more processors and their peripheral circuits. The processor 23 may further include other arithmetic circuits such as a logic arithmetic unit, a numerical arithmetic unit, or a graphics processing unit.

[0180] 15 is a functional block diagram of the processor 23 included in the information processing device 2 included in the optical device 10 of this embodiment. The processor 23 of the information processing device 2 includes, as functional blocks, a detection unit 231, a model generation unit 232, and a texture generation unit 233.

[0181] The detection unit 231 detects the appearance of an object shown in an image formed by light from the optical module 1 and the distance to the object.

[0182] The detection unit 231 detects the appearance of the object by acquiring data (an image representing the object) output from the first imaging unit IS1 corresponding to light including the d-line or g-line formed by the first optical system OS1.

[0183] In addition, for each pixel included in the data output from the second imaging unit IS2 corresponding to the light imaged by the second optical system OS2, the detection unit 231 detects the distance to the object represented by that pixel based on the time required for the light to be received after being emitted from the light source LS and reflected by the object.

[0184] The model generation unit 232 generates shape model information indicating the shape of an object based on the distance to the detected object from the image formed by the light imaged by the optical module 1. The model generation unit 232 generates shape model information indicating the shape of the object so that, for example, the distance represented in the pixel corresponding to the object in the data output from the second imaging unit IS2 becomes the distance to the surface of the object.

[0185] The texture generation unit 233 generates texture information indicating the appearance of the object based on the appearance of the detected object and associates the generated texture information with shape model information. The texture generation unit 233 generates image information represented by pixels corresponding to the object in the data output from the first imaging unit IS1 as texture information indicating the appearance of the object. The texture generation unit 233 also references the respective angles of view of the first optical system OS1 and the second optical system OS2 stored in the memory 22 and the number of pixels in the horizontal and vertical directions in the data output from the first imaging unit IS1 and the second imaging unit IS2, and associates each pixel included in the data output from the first imaging unit IS1 with each pixel included in the data output from the second imaging unit IS2. The texture generation unit 233 then associates the texture information indicating the appearance of the object detected from the data output from the first imaging unit IS1 with shape model information indicating the shape of the object based on the association between the pixels included in the data output from the first imaging unit IS1 and the pixels included in the data output from the second imaging unit IS2.

[0186] The optical device 10 appropriately forms an image of the light that is transmitted through the branching surface BF and the light that is reflected by the branching surface BF out of the incident light, and can detect the appearance of the object and the distance to the object represented in each image.

[0187] Furthermore, the optical device 10 can appropriately image the light that is transmitted through the branching surface BF and the light that is reflected by the branching surface BF out of the incident light, generate shape model information that indicates the shape of the object and texture information that indicates the appearance of the object, and associate the texture information with the shape model information.

[0188] The optical device 10 may include an optical module in which the first optical system OS1 forms an image of near-infrared light and the second optical system OS2 forms an image of visible light, like the optical module 1 of Example 2. In this case, the model generation unit 232 generates shape model information using the data output from the first imaging unit IS1, and the texture generation unit 233 generates texture information using the data output from the second imaging unit IS2.

[0189] Finally, an outline of a method for manufacturing the optical module 1 of this embodiment will be described with reference to Fig. 16. Fig. 16 is a flowchart showing an outline of the method for manufacturing the optical module 1 of this embodiment.

[0190] The method for manufacturing the optical module 1 of this embodiment shown in FIG. 16 includes the following steps S1 to S4.

[0191] Step S1: Prepare a front lens group GF, an optical path splitting member OB having a splitting surface BF, a first rear lens group GR1, and a second rear lens group GR2.

[0192] Step S2: The first optical system OS1 is arranged to include a front lens group GF, an optical path branching member OB, and a first rear lens group GR1.

[0193] Step S3: The second optical system OS2 is arranged to include a front lens group GF, an optical path branching member OB, and a second rear lens group GR2.

[0194] Step S4: In one of the first optical system OS1 and the second optical system OS2, an aperture stop is disposed on the splitting surface BF or on the image plane side of the splitting surface BF.

[0195] In the first modification, step S4A shown below may be executed instead of step S4 in the manufacturing method of the optical module 1 of this embodiment shown in FIG.

[0196] Step S4A: The number of lenses included in the front lens group GF is made smaller than the number of lenses included in either the first rear lens group GR1 or the second rear lens group GR2.

[0197] In the second modification, step S4B shown below may be executed instead of step S4 in the manufacturing method of the optical module 1 of this embodiment shown in FIG.

[0198] Step S4B: The first optical system is made to satisfy the following conditional expression (2): 0.10<Df / TL1≦0.50, where Df is the length on the optical axis from the lens surface of the front lens group closest to the object to the lens surface of the front lens group closest to the image plane, and TL1 is the length on the optical axis from the lens surface of the front lens group closest to the object in the first optical system to the image plane.

[0199] In the third modification, step S4C shown below may be executed instead of step S4 in the manufacturing method of the optical module 1 of this embodiment shown in FIG.

[0200] Step S4C: The front lens group is made to have negative refractive power.

[0201] According to the method for manufacturing an optical module of this embodiment, it is possible to manufacture an optical module that appropriately forms an image from each of the light transmitted through the splitting surface and the light reflected by the splitting surface out of the incident light.

[0202] In each optical system included in the optical module of this embodiment, the lens surface may be spherical or flat, or may be aspherical. Spherical or flat lens surfaces are preferred because they facilitate lens processing and assembly adjustment, and can prevent degradation of optical performance due to errors in processing and assembly adjustment. Furthermore, spherical or flat lens surfaces are preferred because they minimize degradation of imaging performance when the image plane is misaligned.

[0203] In the case where the lens surface is aspherical, the aspherical surface may be formed by grinding glass or by glass molding using a mold having an aspherical shape, or may be formed on the surface of a resin bonded to the surface of the glass. In addition, in the optical system of this embodiment, the lens surface may be a diffractive surface, and the lens may be a gradient index lens (GRIN lens) or a plastic lens.

[0204] Furthermore, an anti-reflection coating having high transmittance over a wide wavelength range may be applied to the lens surfaces of the lenses constituting each optical system included in the optical module of this embodiment, thereby reducing flare and ghosting and achieving high-contrast optical performance.

[0205] In each optical system included in the optical module of this embodiment, instead of providing an independent member as an aperture stop, the role of the lens frame or the like may be substituted.

[0206] It should be understood that those skilled in the art can make various changes, substitutions, and alterations thereto without departing from the spirit and scope of the present disclosure.

[0207] 1 Optical module OS1 First optical system OS2 Second optical system OB Optical path branching member BF Branching surface GF Front lens group GR1 First rear lens group GR2 Second rear lens group ST1, ST2 Aperture stop I1, I2 Image surface LS Light source IS1 First imaging unit IS2 Second imaging unit 10 Optical device 231 Detection unit 232 Model generation unit 233 Texture generation unit

Claims

1. 1. An optical module having a splitting surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and forming an image of the light transmitted through the splitting surface and the light reflected by the splitting surface, a first optical system including, in order from the object side, a front lens group, an optical path branching member including the branching surface, and a first rear lens group having positive refractive power and on which light transmitted by the branching surface is incident; a second optical system including, in order from the object side, the front lens group, the optical path splitting member, and a second rear lens group having a positive refractive power and onto which light reflected by the splitting surface is incident, an optical module in which one of the first optical system and the second optical system is provided with an aperture stop on the splitting surface or on the image plane side of the splitting surface;

2. The optical module according to claim 1 , wherein the first optical system and the second optical system each include an aperture stop on the splitting surface or on an image plane side of the splitting surface.

3. 1. An optical module having a splitting surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and forming an image of the light transmitted through the splitting surface and the light reflected by the splitting surface, a first optical system including, in order from the object side, a front lens group, an optical path branching member including the branching surface, and a first rear lens group having positive refractive power and on which light transmitted by the branching surface is incident; a second optical system including, in order from the object side, the front lens group, the optical path splitting member, and a second rear lens group having a positive refractive power and onto which light reflected by the splitting surface is incident, an optical module in which the number of lenses included in the front lens group is smaller than the number of lenses included in one of the first rear lens group and the second rear lens group.

4. The optical module according to claim 3 , wherein the number of lenses included in the front lens group is smaller than the number of lenses included in the other of the first rear lens group and the second rear lens group.

5. 1. An optical module having a splitting surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and forming an image of the light transmitted through the splitting surface and the light reflected by the splitting surface, a first optical system including, in order from the object side, a front lens group, an optical path branching member including the branching surface, and a first rear lens group having positive refractive power and on which light transmitted by the branching surface is incident; a second optical system including, in order from the object side, the front lens group, the optical path splitting member, and a second rear lens group having a positive refractive power and onto which light reflected by the splitting surface is incident, An optical module that satisfies the following conditions: 0.10 < Df / TL1 ≦ 0.50 however Df: the length on the optical axis from the lens surface of the front lens group closest to the object side to the lens surface of the front lens group closest to the image surface side TL1: the length on the optical axis from the lens surface of the front lens group closest to the object side in the first optical system to the image plane

6. 6. The optical module according to claim 3, wherein the front lens group has a negative refractive power.

7. 2. The optical module according to claim 1, which satisfies the following conditional expression: 0.20 < Dst_im / TL1 < 0.50 however, Dst_im: the length from the aperture stop to the image plane in the first optical system TL1: the length on the optical axis from the lens surface of the front lens group closest to the object side in the first optical system to the image plane

8. 1. An optical module having a splitting surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, and forming an image of the light transmitted through the splitting surface and the light reflected by the splitting surface, a first optical system including, in order from the object side, a front lens group, an optical path branching member including the branching surface, and a first rear lens group having positive refractive power and on which light transmitted by the branching surface is incident; a second optical system including, in order from the object side, the front lens group, the optical path splitting member, and a second rear lens group having a positive refractive power and onto which light reflected by the splitting surface is incident, The front lens group is an optical module having a negative refractive power.

9. 9. The optical module according to claim 1, wherein the following conditional expression is satisfied: 0.30 < f1R / f2R < 3.33 however, f1R: focal length of the first rear lens group f2R: the focal length of the second rear lens group

10. An optical module described in any one of claims 1, 3, 5, and 8, wherein an image formed by light from one of the first optical system and the second optical system is used to detect the appearance of an object represented in the image, and an image formed by light from the other optical system is used to detect the distance to the object represented in the image.

11. The optical module according to claim 10, wherein the F-number of the optical system among the first optical system and the second optical system used to detect the distance to the object is equal to or less than the F-number of the optical system among the first optical system and the second optical system used to detect the appearance of the object.

12. 12. The optical module according to claim 11, which satisfies both of the following conditional expressions: 0.20 < Fno_tof / Fno_img < 1.00 1.00 < Fno_tof < 2.00 however, Fno_tof: F-number of the optical system used to detect the distance to the object, either the first optical system or the second optical system Fno_img: F-number of the optical system used to detect the appearance of the object, either the first optical system or the second optical system

13. 11. The optical module according to claim 10, wherein one of the first optical system and the second optical system used to detect the appearance of the object has a cemented lens, and another of the first optical system and the second optical system used to detect the distance to the object consists of only a single lens.

14. The optical module according to claim 10 , further comprising an illumination unit that emits light used to detect the distance to the object.

15. 9. The optical module according to claim 1, further comprising a first imaging unit that receives light formed by the first optical system and a second imaging unit that receives light formed by the second optical system, wherein one of the first imaging unit and the second imaging unit detects visible light and the other detects near-infrared light.

16. 9. The optical module according to claim 1, wherein the splitting surface transmits one of light having a first wavelength included in visible light and light having a second wavelength included in near-infrared light and reflects the other light.

17. 9. The optical module according to claim 1, wherein the optical path branching member has a prism, one surface of the prism is configured as the branching surface, and the prism has a total reflection surface that totally reflects at least light on the optical axis among the light reflected by the branching surface after passing through the front lens group.

18. 9. The optical module according to claim 1, wherein the following conditional expression is satisfied: 1.00 < Pr1 / f1 < 6.00 however, Pr1: the length on the optical axis from the object side surface of the optical path branching member to the image plane side surface of the optical path branching member in the first optical system f1: focal length of the first optical system

19. 9. The optical module according to claim 1, wherein the following conditional expression is satisfied: 0.83 < θ1 / θ2 < 1.20 however, θ1: full angle of view of the first optical system θ2: full angle of view of the second optical system

20. 9. The optical module according to claim 1, wherein the following conditional expression is satisfied: 70.0° < θ1 however, θ1: full angle of view of the first optical system

21. An optical device comprising the optical module according to claim 1 , for detecting an appearance of an object represented in an image formed by light through the optical module and a distance to the object.

22. An optical module according to any one of claims 1, 3, 5 and 8; a detection unit that detects an appearance of an object shown in an image formed by the light from the optical module and a distance to the object; a model generation unit that generates shape model information indicating a shape of the object based on a distance to the detected object; a texture generation unit that generates texture information indicative of an appearance of the object based on an appearance of the detected object, and associates the generated texture information with the shape model information; An optical device comprising:

23. 1. A method for manufacturing an optical module having a splitting surface that transmits a portion of incident light and reflects at least a portion different from the portion of the incident light, the method comprising the steps of: forming an image of light transmitted through the splitting surface and light reflected by the splitting surface, the method comprising the steps of: a first optical system is arranged to include, in order from the object side, a front lens group, an optical path branching member having the branching surface, and a first rear lens group having a positive refractive power and on which light transmitted by the branching surface is incident; a second optical system is arranged to include, in order from the object side, the front lens group, the optical path splitting member, and a second rear lens group having a positive refractive power and onto which the light reflected by the splitting surface is incident; A method for manufacturing an optical module, comprising: disposing an aperture stop on the splitting surface or on an image plane side of the splitting surface in one of the first optical system and the second optical system.