Medical imaging system and imaging device
The present disclosure relates to a medical imaging system and an imaging device capable of achieving high image quality with a simpler configuration. An imaging module includes a branching optical system that branches light incident via an imaging lens in three directions and emits the light, and three imaging elements that receive light emitted from the branching optical system in the three directions and perform imaging. Then, the three imaging elements are arranged at positions having different optical distances from the principal point of the imaging lens by a shift amount ΔZ, and the shift amount ΔZ is calculated from ΔZ=2×DoF×M (1<M<2) by using a depth of focus DoF of the imaging lens set on the basis of a pixel pitch p of the imaging elements and an aperture value F of the imaging lens, and a correction term M. The present technology can be applied to, for example, a medical imaging system.
1 . A medical imaging system comprising:
an imaging module provided in a medical imaging device, the imaging module including
a branching optical system that branches light incident via an imaging lens in at least two directions and emits the light, and
two or more light receiving regions of an image sensor configured to receive the light emitted from the branching optical system in the at least two directions, respectively, and perform imaging; and
an image processing circuitry configured to perform image processing of generating an extended depth of field (EDoF) image with an extended depth of field by using images captured by the two or more light receiving elements,
the two or more light receiving regions being arranged at positions having different optical distances from a principal point of the imaging lens by a shift amount ΔZ, and
the shift amount ΔZ being calculated as ΔZ=2×DoF×M (1<M<2) by using a depth of focus DoF of the imaging lens set on a basis of a pixel pitch p of the two or more light receiving regions and an aperture value F of the imaging lens, and a correction term M.
2 . The medical imaging system according to claim 1 , wherein the depth of focus DoF is calculated as
DoF=Δ EW ×P×F
by using an edge blur width Δ EW of a black-and-white edge image, the pixel pitch p of the two or more light receiving regions and the aperture value F of the imaging lens.
3 . The medical imaging system according to claim 1 , wherein the correction term M is determined on a basis of wave optics.
4 . The medical imaging system according to claim 1 , wherein the correction term M satisfies 1<M<1.5.
5 . The medical imaging system according to claim 1 ,
wherein the branching optical system branches light incident via the imaging lens in three directions and emits the light, and
as the two or more light receiving regions,
a first light receiving region arranged at a reference position with respect to the branching optical system,
a second light receiving region arranged at a position farther from the branching optical system than the reference position by the shift amount ΔZ, and
a third light receiving region arranged at a position closer to the branching optical system than the reference position by the shift amount ΔZ
are provided.
6 . The medical imaging system according to claim 5 ,
wherein the branching optical system includes a prism block in which a first prism that emits light to the first light receiving region, a second prism that emits light to the second light receiving region, and a third prism that emits light to the third light receiving region are joined in a gapless structure,
a first optical thin film that branches light in a specific wavelength band with a light amount at which a ratio of average reflectance to average transmittance is 1:2 is provided between the first prism and the second prism, and
a second optical thin film that branches light in a specific wavelength band at a light amount at which a ratio of average reflectance to average transmittance is 1:1 is provided between the second prism and the third prism.
7 . The medical imaging system according to claim 6 , wherein the specific wavelength band includes a visible light band from 400 nm to 700 nm.
8 . The medical imaging system according to claim 1 ,
wherein the branching optical system branches light incident via the imaging lens in two directions and emits the light, and
as the two or more light receiving regions,
a first light receiving region arranged at a reference position with respect to the branching optical system, and
a second light receiving region arranged at a position farther from or closer to the branching optical system than the reference position by the shift amount ΔZ
are provided.
9 . The medical imaging system according to claim 8 ,
wherein the branching optical system includes a prism block in which a first prism that emits light to the first light receiving region and a second prism that emits light to the second light receiving region are joined in a gapless structure, and
an optical thin film that branches light in a specific wavelength band at a light amount at which a ratio of average reflectance to average transmittance is 1:1 is provided between the first prism and the second prism.
10 . The medical imaging system according to claim 9 , wherein the specific wavelength band includes a visible light band from 400 nm to 700 nm.
11 . The medical imaging system according to claim 1 further comprising an optical element that depolarizes light incident on the branching optical system.
12 . An imaging device comprising:
an imaging module including a branching optical system that branches light incident via an imaging lens in at least two directions and emits the light, and two or more light receiving regions that receive the light emitted from the branching optical system in the at least two directions, respectively, and perform imaging,
the two or more light receiving regions being arranged at positions having different optical distances from a principal point of the imaging lens by a shift amount ΔZ, and
the shift amount ΔZ being calculated as ΔZ=2×DoF×M (1<M<2) by using a depth of focus DoF of the imaging lens set on a basis of a pixel pitch p of the two or more light receiving regions and an aperture value F of the imaging lens, and a correction term M.