WO2007083783A1 - 光学的ローパスフィルタおよびこれを用いた撮像装置 - Google Patents
光学的ローパスフィルタおよびこれを用いた撮像装置 Download PDFInfo
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- WO2007083783A1 WO2007083783A1 PCT/JP2007/050861 JP2007050861W WO2007083783A1 WO 2007083783 A1 WO2007083783 A1 WO 2007083783A1 JP 2007050861 W JP2007050861 W JP 2007050861W WO 2007083783 A1 WO2007083783 A1 WO 2007083783A1
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- liquid crystal
- shooting mode
- image
- pass filter
- optical low
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- 230000003287 optical effect Effects 0.000 title claims abstract description 118
- 238000003384 imaging method Methods 0.000 title claims abstract description 32
- 238000000926 separation method Methods 0.000 claims abstract description 41
- 239000004973 liquid crystal related substance Substances 0.000 claims description 134
- 238000006243 chemical reaction Methods 0.000 claims description 16
- 230000010287 polarization Effects 0.000 claims description 12
- 239000013078 crystal Substances 0.000 claims description 11
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 claims description 9
- 230000001629 suppression Effects 0.000 abstract description 4
- 238000010586 diagram Methods 0.000 description 16
- 239000003086 colorant Substances 0.000 description 14
- 230000000694 effects Effects 0.000 description 6
- 238000005070 sampling Methods 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- 238000006073 displacement reaction Methods 0.000 description 3
- GQYHUHYESMUTHG-UHFFFAOYSA-N lithium niobate Chemical compound [Li+].[O-][Nb](=O)=O GQYHUHYESMUTHG-UHFFFAOYSA-N 0.000 description 3
- 238000001914 filtration Methods 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 241000579895 Chlorostilbon Species 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 239000013256 coordination polymer Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000010976 emerald Substances 0.000 description 1
- 229910052876 emerald Inorganic materials 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
- H01L27/144—Devices controlled by radiation
- H01L27/146—Imager structures
- H01L27/14601—Structural or functional details thereof
- H01L27/1462—Coatings
- H01L27/14621—Colour filter arrangements
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/60—Control of cameras or camera modules
- H04N23/667—Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
- H04N23/80—Camera processing pipelines; Components thereof
- H04N23/84—Camera processing pipelines; Components thereof for processing colour signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/10—Circuitry of solid-state image sensors [SSIS]; Control thereof for transforming different wavelengths into image signals
- H04N25/11—Arrangement of colour filter arrays [CFA]; Filter mosaics
- H04N25/13—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements
- H04N25/134—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements based on three different wavelength filter elements
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
- H04N25/10—Circuitry of solid-state image sensors [SSIS]; Control thereof for transforming different wavelengths into image signals
- H04N25/11—Arrangement of colour filter arrays [CFA]; Filter mosaics
- H04N25/13—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements
- H04N25/135—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements based on four or more different wavelength filter elements
- H04N25/136—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements based on four or more different wavelength filter elements using complementary colours
Definitions
- the present invention relates to an optical low-pass filter and an image pickup apparatus using the same, and more particularly to an optical filter that removes high-frequency components using image blurring.
- hybrid cameras allow both cameras and still images to be taken with a single camera.
- a device has been devised to improve the quality of the video and still images that are shot.
- an image sensor with a large number of pixels is used to increase the resolution of still images.
- suppressing the occurrence of false colors (color moire) due to sampling is an important factor in improving image quality.
- An image sensor is a collection of minute pixels, and capturing an optical image with the image sensor is equivalent to sampling a signal at an interval of pixel pitch.
- the imaging light incident on the image sensor is filtered (for example, see Patent Documents 1 and 2).
- Patent Document 1 Japanese Patent Application Laid-Open No. 6-290920 3
- Patent Document 2 Japanese Patent No. 2 5 5 6 8 3 1
- An optical low-pass filter is an optical filter that consists of a birefringent plate made of quartz or lithium niobate and that removes high-frequency components using the birefringence of light. That is, as shown in FIG. 3, the birefringent plate has the property of separating the incident light line into an ordinary ray and an extraordinary ray. A double image is formed on the image plane of the element by superimposing the image by the ordinary ray and the image by the extraordinary ray. As a result, the double folded plate is an optical low pass filter that removes from the subject image a spatial frequency component corresponding to a wavelength twice as large as the ray separation width (interval between the ordinary ray and the extraordinary ray). It will function as a filter.
- the beam separation width is proportional to the thickness of the birefringent plate, if the thickness of the birefringent plate is determined so that the separation ⁇ wealth of the double image is almost equal to the pixel pitch of the image sensor, false color generation will occur. It can be suppressed. Disclosure of the invention
- the pixel pitch of the G color (green) in the vertical and horizontal directions is d. ,. R (red) and B (blue) images Since the elementary pitch is 2d, the Nyquist frequencies for the R and B colors are fs
- the optimal optical low-pass filter Bx Ah is as above.
- the effect of the optical low-pass filter cannot be strengthened until the resolution of the output image is impaired.
- the sampling frequency of the output image is F s and the pixel pitch is
- the G color Nyquist frequency is fs / 2 and the G color false color is not very noticeable, but the R color and B color Nyquist frequency is fs 4, so the false color due to the R color and B color is false. The color will remain. However, even in such a case, if the subject itself does not have a high frequency component, false color does not occur.
- the cut-off frequency fc of the optical low-pass filter is set according to this trend as described above.
- the viewpoint of resolution is given priority over color, but the applicant has devised a camera that satisfies both the viewpoints of color and resolution at the same time (for example, see Patent Document 3).
- one output image signal is generated from N pixel signals generated by the image sensor.
- the relationship between the pixel pitch d of the image sensor and the pixel pitch D of the output image is d ⁇ D.
- the cut-off frequency fc of the optical mouth / one-pass filter can be set so as to satisfy both the viewpoint of color and the viewpoint of resolution.
- Patent Document 3 Japanese Patent Application 2 0 0 4— 1 5 6 0 8 3
- the optical frequency response is appropriate for both still images and movies at the same time.
- the present invention has been made in view of such circumstances, and for moving images, the resolution of the output image is sacrificed. In addition to making it possible to effectively suppress the generation of false colors without causing a failure, the objective is to make it possible to sufficiently increase the resolution of still images while suppressing the generation of false colors as much as possible.
- this optical bright-pass filter can reduce the degree of blurring of the image formed on the image sensor depending on whether it is a still image shooting mode or a moving image shooting mode.
- Variable control is performed.
- the beam separation width can be set to the first width in the still image shooting mode by variably controlling the beam separation width according to the still image shooting mode or the movie shooting mode. Therefore, the blurring of the image is the first amount, and in the movie shooting mode, the image separation is reduced by setting the light beam separation width to the second width that is wider than the first width. I'm trying to make it the second quantity.
- the image pickup apparatus of the present invention using such an optical low-pass filter includes an image pickup device having a number of pixels larger than the number of display pixels defined in the video standard, and is in a video shooting mode. Is designed to generate one output image signal from N pixel signals generated by the image sensor.
- the light beam separation width in the optical mouth-one-pass filter in the still image shooting mode, can be controlled to be relatively narrow. Since the cut-off frequency of an optical low-pass filter depends on the light separation width, the light separation width is made relatively narrow so that the cut-off frequency is approximately fs 2 or slightly higher than this frequency.
- the resolution of the image sensor can be utilized as it is, and the generation of false colors can be suppressed to some extent. As a result, the high resolution requirement that is strongly demanded is satisfied, and stillness with minimal false color suppression is provided. A picture can be obtained.
- the light separation width of the optical low-pass filter is controlled to be relatively wide, and one output image signal is generated from the N pixel signals generated by the image sensor. Will be generated. Ray separation.
- the output image can be controlled by making the width relatively wide and the cut-off frequency corresponding to the Nyquist frequency of the pixel of the output image or slightly exceeding this frequency.
- the high-frequency component corresponding to the resolution component unnecessary for the signal can be cut by the optical low-pass filter.
- Figure 1 is a frequency characteristic diagram showing the principle of false color generation.
- Fig. 2 shows the frequency characteristics of an optical low-pass filter that cuts false colors.
- Figure 3 shows the basic principle of the optical mouth-pass filter.
- Figure 4 shows the pixel pitch of the Bayer array.
- FIG. 5 is a diagram illustrating main components of the imaging apparatus according to the present embodiment.
- FIG. 6 is a diagram for explaining the birefringence of the liquid crystal.
- FIG. 7 is a diagram illustrating a configuration example of the optical low-pass filter according to the present embodiment.
- FIG. 8 is a diagram illustrating an example of resolution conversion processing performed by the output image signal generation unit.
- FIG. 9 is a diagram illustrating an example of resolution conversion processing performed by the output image signal generation unit.
- FIG. 10 is a diagram illustrating an example of resolution conversion processing performed by the output image signal generation unit.
- FIG. 11 is a diagram showing another configuration example of the optical low-pass filter according to the present embodiment.
- FIG. 12 is a diagram illustrating an arrangement of liquid crystal molecules in the polarizing liquid crystal layer illustrated in FIG. 11.
- FIG. 13 is a diagram illustrating another configuration example of the optical one-pass filter according to the present embodiment.
- FIG. 14 is a diagram showing another configuration example of the optical low-pass filter according to the present embodiment.
- FIG. 15 is a diagram showing another configuration example of the optical one-pass filter according to the present embodiment. '' Best mode for carrying out the invention
- FIG. 5 is a diagram illustrating main components of the imaging device 1 according to the present embodiment.
- the imaging apparatus 1 of the present embodiment includes an imaging optical system 3 having an optical low-pass filter 2, a color filter 4 that separates imaging light output from the imaging optical system 3 into predetermined color components, and The image sensor 5 that photoelectrically converts the imaged light that has passed through the color filter 4 ′ to generate an image signal, and the output image signal is generated based on the pixel signal acquired from the image sensor 5.
- the optical low-pass filter 2 of the present embodiment is composed of, for example, a birefringent plate made of liquid crystal, and is disposed in front of the image sensor 5 on the optical path of the imaged light.
- the dielectric constant of a material is anisotropic, the incident light on the material is separated into two light beams with different polarization directions depending on the relationship with the vibration direction.
- the optical low-pass filter 2 is a birefringent plate made of liquid crystal
- the incident light beam 'on the birefringent plate oscillates in a direction perpendicular to the polarization direction (long axis direction) of the liquid crystal molecules 2 1.
- the ordinary ray is depicted as polarized light that oscillates perpendicular to the paper surface
- the extraordinary ray is depicted as polarized light that oscillates in the paper surface.
- the frequency characteristic of the optical low-pass filter 2 can be switched depending on whether the still image shooting mode or the moving image shooting mode is set.
- the switching of the frequency characteristics of the optical low-pass filter 2 is realized by variably controlling the distance between the ordinary ray and the extraordinary ray (referred to as the optical beam separation width) in the birefringent plate.
- the optical beam separation width the distance between the ordinary ray and the extraordinary ray
- the cutoff frequency of the optical low-pass filter 2 decreases, and the degree of blurring of the image formed on the image sensor 5 increases.
- the cut-off frequency of the optical low-pass filter 2 is increased, and the degree of blurring of the image formed on the image sensor 5 is reduced.
- the light separation width is set to the first width, so that the image blur is set to the first amount, and in the video shooting mode, the light separation width is set to the first amount.
- the second width is wider than the width of 1, the degree of blurring of the image is set to a second amount larger than the first amount.
- the first filter is used. Width is optical
- the second component is used to cut out high-frequency components corresponding to resolution components that are not necessary for the output image signal, and to suppress false colors with a strong margin.
- the width should be such that the cut-off frequency of the optical low-pass filter 2 corresponds to the Nyquist frequency of the pixel of the output image or slightly exceeds this frequency.
- the beam separation width in the optical low-pass filter 2 can be made variable by controlling the voltage applied to the liquid crystal. That is, as shown in FIG. 7, the optical mouth-pass filter 2 of this embodiment includes a birefringent layer 11 1 (corresponding to the variable focal layer of the present invention) made of, for example, liquid crystal. The orientation of the liquid crystal molecules in the birefringent layer 1 1 changes depending on the applied voltage, and the refractive index for extraordinary rays changes. By utilizing the electric field control birefringence effect of the liquid crystal, the light separation width of the optical low-pass filter 2 can be changed.
- Fig. 7 (a) when a relatively small voltage VI is applied to the liquid crystal of the birefringent layer 1 1, the inclination of the liquid crystal molecules 2 1 becomes smaller with respect to the incident optical axis. Has a relatively narrow first width W 1.
- Fig. 7 (b) when a relatively large voltage V 2 (V 1 ⁇ V 2) is applied to the liquid crystal of the birefringent layer 11, the liquid crystal molecules 2 1 Since the inclination of the beam increases, the beam separation width becomes a relatively wide second width W 2 (W 1 ⁇ W 2).
- the imaging optical system 3 plays a role of guiding imaging light to the imaging element 5.
- the optical low-pass filter 2 is included, and a photographing lens, an infrared filter, and the like are configured.
- the infrared filter is intended to block the infrared rays incident on the photodiode, and is disposed in front of the optical low-pass filter 2 and includes one glass block. Configured.
- the color filter 4 is regularly arranged in a predetermined pattern on the light receiving surface of each pixel constituting the imaging device 5 and plays a role of filtering the imaging light into a predetermined color component.
- primary color filters of R, G, and B are used as the three colors of the first color, the second color, and the third color that form the color filter 4.
- the present invention is not limited to these, and may be a complementary color filter composed of C (cyan), M (magenta), and Y (yellow), or another color combination.
- an emerald filter may be added to the three-color filter.
- the G color filter is arranged in a checkered pattern, and the R color filter and the B color filter are arranged in each row.
- An alternating bay arrangement is used, but this is not a limitation.
- the image sensor 5 plays a role of photoelectrically converting received image light into electrical image information, storing it as a charge amount, and outputting it as an electrical signal to the output image signal generator 6. is there.
- the image sensor 5 has a plurality of pixels (photodiodes) arranged in a predetermined pattern, and the color filters 4 are regularly arranged in a predetermined pattern on the light receiving surface of each pixel.
- the number of pixels of the image sensor 5 according to this embodiment is larger than the number of display pixels (about 350,000 pixels for the SD standard and about 200,000 pixels for the HD standard) defined in the video standard ( For example, it is set to N times the number of display pixels of the HD standard (N is a real number of 2 or more) or more.
- the output image signal generation unit 6 performs a role of performing AZD conversion on the pixel signal acquired from each pixel of the image sensor 5 and performing various image processing to generate an output image signal.
- the output image signal generation unit 6 includes an AZD converter 7 and an ISP 8, and is electrically connected to the image sensor 5. It has been continued.
- the AZD converter 7 converts the pixel signal, which is an analog electrical signal, into digital data.
- C P U 9 controls the voltage applied to the liquid crystal of the optical low-pass filter 2 and controls the shooting mode for I S P 8. That is, in the still image shooting mode, the voltage V 1 is applied to the liquid crystal and control is performed so that the still image shooting mode is set for I S P 8. In addition, in the video shooting mode, the voltage V 2 is applied to the liquid crystal and control is performed to set the video shooting mode for I S P 8.
- ISP 8 performs optical black processing, white balance processing, color correction processing, color interpolation processing, noise suppression processing, contour enhancement processing, and T correction processing on the A / D converted pixel signal. Perform various image processing such as high resolution conversion processing to generate output image signal. At this time, I S P 8 performs image processing for still images or moving images according to the shooting mode set from C P U 9.
- the conversion ratio of the resolution conversion process is set so that N pixel signals that have undergone AZD conversion correspond to one output image signal. That is, the ISP 8 generates N output image signals from the N pixel signals generated by the image sensor 5 in the still image shooting mode, and uses the image sensor 5 in the video shooting mode. One output image signal is generated from the generated N pixel signals. Even in the still image shooting mode, resolution conversion processing may be performed if requested by the user.
- FIGS. 8 to 10 are diagrams showing examples of resolution conversion processing by ISP 8.
- the ISP 8 of the present embodiment is configured by, for example, CPU, DSP (Digital Signal Processor), or hard-wired logic.
- the A / D converted pixel signal may be taken into a PC (Personal Computer) and the above-described image processing may be performed by various programs.
- the operation of the imaging apparatus according to the present embodiment configured as described above will be described.
- the voltage V 1 is applied to the liquid crystal of the optical low-pass filter 2 as shown in Fig. 7 (a), and the first beam separation width is relatively narrow.
- the width is controlled to be W 1.
- the false color generated by the sampling in the image sensor 5 can be suppressed to some extent.
- the filtering effect of the optical low-pass filter 2 does not become too strong, and the pixel signal of the image sensor 5 does not become deficient. Therefore, the resolution of the optical low-pass filter 2 is reduced as much as possible. Can be suppressed.
- the imaging light that has passed through the optical low-pass filter 2 and the color filter 4 is imaged by the imaging device 5 and a pixel signal is generated by photoelectric conversion. Then, the pixel signal generated by the image sensor 5 is output to the output image signal generation unit 6, where an output image signal is generated. At this time, N output image signals are generated from the N pixel signals generated by the image sensor 5. In other words, the resolution of the image sensor 5 is utilized as it is, and a high-resolution output image signal is generated.
- the voltage V 2 is applied to the liquid crystal of the optical mouth pass filter 2 as shown in Fig. 7 (b), and the light separation width is relatively It is controlled to have a wide second width W2.
- the cut-off frequency fc of the optical low-pass filter 2 is set to a frequency corresponding to the Nyquist frequency of the pixel of the output image, or to be slightly higher than this frequency. As a result, generation of false colors can be suppressed more strongly than in the still image shooting mode while maintaining a sufficient resolution in the output image.
- the imaging light that has passed through the optical low-pass filter 2 and the color filter 4 is imaged by the imaging device 5 and a pixel signal is generated by photoelectric conversion. Then, the pixel signal generated by the image sensor 5 is output to the output image signal generation unit 6 where an output image signal is generated. At this time, one output image signal is generated from the N pixel signals generated by the image sensor 5. That is, the number of pixels of the image sensor 5 is the number of display pixels required by the video standard. The output image signal corresponding to the number of display pixels is generated from the N pixel signals obtained by the imaging element 5 having an extra number of pixels.
- the minimum necessary false color is suppressed and a high-resolution still image can be obtained.
- the moving image shooting mode it is possible to obtain a moving image that satisfies the display resolution required by the moving image standard and in which false colors are effectively suppressed.
- the light separation width is changed by controlling the voltage applied to the liquid crystal of the optical low-pass filter 2, so that the optimum frequency characteristics and moving image shooting mode are suitable for the still image shooting mode. It is possible to easily switch between the optimal frequency characteristics for the mode.
- the optical low-pass filter 2 is described as being made of a birefringent plate made of liquid crystal, but the present invention is not limited to this. That is, any material that has a birefringence effect of light and whose light separation width can be electrically controlled can be applied as a material for the optical single pass filter 2.
- the example in which the birefringence is dynamically changed by one liquid crystal plate as shown in FIG. 7 has been described. It is not limited. For example, as shown in Fig. 11, it is possible to change the birefringence dynamically by using a plurality of liquid crystal plates.
- the optical low-pass filter 2 has the polarization state of incident light ( Twisted nematic-type polarizing liquid crystal layer 3 1 that can control the optical rotation), and are arranged on the incident side and the exit side of the polarizing liquid crystal layer 3 1, respectively.
- a pair of liquid crystal layers 3 2 and 3 3 (corresponding to a pair of birefringent layers according to claim 5).
- the tilt directions of the crystal axes of the liquid crystal layers 3 2 and 3 3 may be the same or different from each other.
- the polarizing liquid crystal layer 3 1 and the pair of liquid crystal layers 3 2 and 3 3 constitute the variable focus layer of the present invention. '
- the incident light on one liquid crystal layer 3 2 is controlled by variably controlling the polarization state in the polarized liquid crystal layer 31 according to the still image shooting mode or the movie shooting mode.
- the separation width of the output light beam obtained by passing through the polarizing liquid crystal layer 3 1 and the pair of liquid crystal layers 3 2 and 3 3 is shown in Fig. 11 (a) in the still image shooting mode.
- the width W 1 is set to the second width W 2 as shown in FIG. 11 (b) in the video recording mode.
- the polarization state of the polarization liquid crystal layer 3 1 can be controlled by the presence or absence of an applied voltage to the polarization liquid crystal layer 3 1.
- FIG. 12 is a diagram showing the arrangement of the liquid crystal molecules 2 1 in the polarizing liquid crystal layer 3 1.
- the liquid crystal molecules 2 1 are aligned along the grooves.
- the liquid crystal molecules 2 1 are twisted by 90 degrees in the liquid crystal layer.
- the vibration direction of light changes by 90 degrees before and after passing through the polarizing liquid crystal layer 3 1.
- the alignment of the liquid crystal molecules 2 1 changes. That is, the liquid crystal molecules 21 are arranged with an angle corresponding to the magnitude of the applied voltage with respect to the alignment films 3 1 a and 3 1 b.
- the CPU 9 controls the presence or absence of the applied voltage, so that the liquid crystal molecules 21 are 0 degrees (parallel) or 90 degrees with respect to the alignment films 3 1 a and 3 1 b as shown in FIG. Control to be either degree (right angle).
- the incident light beam is first divided into an ordinary ray and an extraordinary ray by one liquid crystal layer 32, and is emitted by being separated by ⁇ A spatially.
- ordinary rays are depicted as polarized light that vibrates perpendicularly to the plane of the paper, and extraordinary rays are depicted as backward polarized light that vibrates in the plane of the paper.
- the ordinary and extraordinary rays separated by one liquid crystal layer 3 2 are then incident on the polarizing liquid crystal layer 3 1.
- the first width W 1 which is the light separation width of the entire optical mouth-pass filter 2 is W 1 ⁇ ⁇ ⁇ — ⁇ ⁇ It becomes.
- the light beam separation width can be variably controlled depending on the presence or absence of an applied voltage to the polarizing liquid crystal layer 31. Therefore, it is not necessary to prepare two different applied voltages V I and V 2 as in the example of Fig. 7. In the case of Fig. 7, it is necessary to apply voltage when either the still image shooting mode or the movie shooting mode is set, but in the case of Fig. 11, the still image shooting mode is set. There is no need to apply a voltage, and power consumption can be reduced.
- liquid crystal layers 3 2 and 3 3 are used as an example of the pair of birefringent layers, but quartz or lithium niobate may be used instead of the liquid crystal.
- the pair of liquid crystal layers 3 2 and 3 3 are arranged on the incident side and the emission side of the polarizing liquid crystal layer 31, but the present invention is not limited to this.
- the optical low-pass filter 2 may be configured by overlapping two liquid crystal layers 1 1 and 3 2. That is, in the configuration shown in FIG. 13, the same liquid crystal layer 3 2 as in FIG. 11 (invoice) is formed on the incident side of the liquid crystal layer 1 1 as in FIG. 7 (corresponding to the first birefringent layer in claim 6). Corresponding to the second birefringent layer in Item 6).
- the crystal axis of the upper liquid crystal layer 32 is inclined with a predetermined fixed angle with respect to the optical axis of the incident light beam. Also located in the lower layer The inclination of the crystal axis of the liquid crystal layer 11 changes depending on the presence or absence of an applied voltage.
- the incidence on the upper liquid crystal layer 3 2 is controlled by controlling the presence or absence of the voltage applied to the lower liquid crystal layer 1 1 according to the still image shooting mode or the moving image shooting mode.
- the separation width of the output light beam obtained by the light beam passing through the lower liquid crystal layer 11 is the first width W 1 as shown in Fig. 13 (a) in the still image shooting mode.
- the second width W 2 is set as shown in Fig. 13 (b).
- the incident light beam is first divided into an ordinary ray and an extraordinary ray by the upper liquid crystal layer 3 2, and is spatially separated and emitted by ⁇ A.
- ordinary rays are depicted as polarized light that oscillates perpendicular to the paper surface
- extraordinary rays are depicted as polarized light that oscillates on the paper surface.
- the ordinary ray and the extraordinary ray separated by the upper liquid crystal layer 3 2 are incident on the lower liquid crystal layer 1 1.
- ⁇ -Here, as shown in Fig. 13 (a) when the applied voltage to the lower liquid crystal layer 11 is off, the liquid crystal molecules are parallel to the optical axis of the incident light.
- the first width W 1 which is the light separation width of the entire optical mouth-pass filter 2 becomes W 1 ⁇ .
- the beam separation width can be variably controlled depending on the presence / absence of an applied voltage to the lower liquid crystal layer 11. Therefore, it is not necessary to prepare two different applied voltages V I and V 2. In addition, it is not necessary to apply a voltage in the still image shooting mode, and the power consumption can be reduced.
- the liquid crystal layer 3 2 is used as an example of the birefringent layer disposed on the incident side of the liquid crystal layer 11, but crystal or lithium niobate is used instead of the liquid crystal. Also good.
- FIG. 13 shows an example in which the liquid crystal layer 3 2 is arranged on the incident side of the liquid crystal layer 11, but the liquid crystal layer 3 2 may be arranged on the emission side of the liquid crystal layer 11. .
- the liquid crystal layer 11 does not necessarily need to be made of liquid crystal. In other words, any material that has the effect of birefringence of light and can electrically control the beam separation width can be used in place of the liquid crystal layer 1 1.
- FIG. 14 is a diagram showing another configuration example of the optical low-pass filter 2.
- the optical low-pass filter 2 shown in Fig. 14 has two low-pass filters 4 1 and 4 2 having the three-layer structure shown in Fig. 11.
- the planes including the crystal axes are orthogonal or oblique to each other. In this way, it is configured by placing a 1-wave plate 4 3 (having the effect of converting linearly polarized light into circularly polarized light) between them.
- the incident light is separated into an ordinary ray and an extraordinary ray along the X-axis direction by the first-stage optical low-pass filter 4 1.
- the second optical low-pass filter 42 separates the two incident rays from the quarter-wave plate 43 into normal and extraordinary rays along the y-axis, respectively. , Two-dimensional Into four rays.
- the configuration for separating one incident beam into a plurality of beams in a two-dimensional manner is not limited to the configuration shown in FIG.
- a configuration as shown in Fig. 15 is also possible.
- the black circles indicate the positional relationship between the separated rays.
- the configuration of Fig. 15 (a) includes two one-dimensional optical low-pass filters of the configuration shown in Fig. 7, Fig. 11 or Fig. 13, and their planes including crystal axes are orthogonal or oblique to each other. Arrange them so that they overlap.
- the two one-dimensional optical low-pass filters that are placed one on top of the other can adopt either one of Fig. 7, Fig. 11 or Fig. 13 and have the same configuration. Any one of the two shown in FIGS. 11 and 13 may be adopted to have different configurations.
- the configuration of Fig. 15 (b) includes three one-dimensional optical low-pass filters of the configuration shown in Fig. 7, Fig. 11 or Fig.
- the three one-dimensional optical low-pass filters that are placed one on top of the other can adopt any one of Fig. 7, Fig. 11 and Fig. 13 and have the same configuration. Any two or three of Fig. 11 and Fig. 13 may be adopted and combined in any order.
- the configuration of Fig. 15 (c) includes two one-dimensional optical low-pass filters of the configuration shown in Fig. 7, Fig. 11 or Fig. 13, and their planes containing crystal axes are orthogonal or oblique to each other. In this way, a quarter wave plate is placed between them.
- the two one-dimensional optical low-pass buinoleators placed on both sides of the quarter-wave plate adopt either one of Fig. 7, Fig. 11 or Fig. 13 and have the same configuration.
- any two of Fig. 7, Fig. 11 and Fig. 13 may be adopted and combined.
- Figure 14 shows an example in which a one-dimensional optical low-pass filter with the configuration shown in Fig. 11 is placed on both sides of the quarter-wave plate. This corresponds to the configuration of
- variable focal layer for changing the degree of blur of an image formed on the image sensor 5
- the variable focal layer may be constituted by a liquid crystal lens.
- a liquid crystal lens is a type of lens that uses liquid crystal.
- the apparent refractive index of the liquid crystal changes.
- the focal length of the lens changes when the refractive index of the liquid crystal that forms the lens changes.
- the focal length of the lens can be changed by controlling only the electrical signal.
- variable focus layer When a liquid crystal lens is used as the variable focus layer, the application of voltage to the liquid crystal lens is controlled according to the still image shooting mode or the moving image shooting mode. Variable control of focal length through rate change. As a result, the image blur is the first amount in the still image shooting mode, and the image blur is the second amount in the video shooting mode.
- the pixel array of the image sensor 5 is a square lattice array
- the present invention is not limited to this.
- a 45 ° inclined square lattice arrangement may be used.
- the still image shooting mode and the moving image shooting mode can be set by a user operating a mode setting operator (not shown) provided in the imaging apparatus 1. It is.
- a mode setting operator not shown
- the camera automatically switches to the still image shooting mode temporarily. It is also possible to do this.
- the mode information set in this way is stored in a memory (not shown) of the imaging apparatus 1.
- CP U 8 controls the applied voltage to the optical low-pass filter 2 by referring to the mode information stored in this memory.
- the optical low-pass filter of the present invention is useful for a hybrid camera configured so that both a moving image and a still image can be taken with a single camera.
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Power Engineering (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Color Television Image Signal Generators (AREA)
- Polarising Elements (AREA)
- Blocking Light For Cameras (AREA)
- Studio Devices (AREA)
- Liquid Crystal (AREA)
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP07713665A EP1978753A4 (en) | 2006-01-20 | 2007-01-16 | OPTICAL LOW PASS FILTER AND IMAGING DEVICE THEREFOR |
US12/161,648 US20090169126A1 (en) | 2006-01-20 | 2007-01-16 | Optical low pass filter and imaging device using the same |
JP2007554995A JP4558804B2 (ja) | 2006-01-20 | 2007-01-16 | 撮像装置 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2006-012672 | 2006-01-20 | ||
JP2006012672 | 2006-01-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2007083783A1 true WO2007083783A1 (ja) | 2007-07-26 |
Family
ID=38287728
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2007/050861 WO2007083783A1 (ja) | 2006-01-20 | 2007-01-16 | 光学的ローパスフィルタおよびこれを用いた撮像装置 |
Country Status (7)
Country | Link |
---|---|
US (1) | US20090169126A1 (ja) |
EP (1) | EP1978753A4 (ja) |
JP (1) | JP4558804B2 (ja) |
KR (1) | KR20080089601A (ja) |
CN (1) | CN101366289A (ja) |
TW (1) | TW200730880A (ja) |
WO (1) | WO2007083783A1 (ja) |
Cited By (8)
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WO2011105581A1 (ja) * | 2010-02-26 | 2011-09-01 | 旭硝子株式会社 | 光学ローパスフィルタおよびデジタルカメラ |
JP2011232650A (ja) * | 2010-04-28 | 2011-11-17 | Asahi Glass Co Ltd | 光学ローパスフィルタ及びデジタルカメラ |
JP2012005044A (ja) * | 2010-06-21 | 2012-01-05 | Nikon Corp | ディジタルカメラ |
JP2012175449A (ja) * | 2011-02-22 | 2012-09-10 | Sony Corp | 撮像装置、撮像方法及び撮像制御プログラム |
JP2012225958A (ja) * | 2011-04-14 | 2012-11-15 | Asahi Glass Co Ltd | 光学ローパスフィルタおよび撮像機器 |
WO2015029388A2 (en) | 2013-08-28 | 2015-03-05 | Sony Corporation | Optical low pass filter, image pickup device, and image pickup apparatus |
JP2018004913A (ja) * | 2016-06-30 | 2018-01-11 | キヤノン株式会社 | 光学ローパスフィルタおよびそれを有する撮像装置、撮像ユニット |
CN108697308A (zh) * | 2016-03-09 | 2018-10-23 | 索尼公司 | 图像处理装置、图像处理方法和记录介质 |
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DE102016112968B4 (de) * | 2016-07-14 | 2018-06-14 | Basler Ag | Bestimmung von Farbwerten für Pixel an Zwischenpositionen |
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CN113747035A (zh) * | 2021-10-12 | 2021-12-03 | 维沃移动通信有限公司 | 摄像头模组和电子设备 |
Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6472119A (en) * | 1987-09-11 | 1989-03-17 | Canon Kk | Optical low-pass filter |
JPH06292093A (ja) | 1993-03-31 | 1994-10-18 | Sony Corp | 撮像装置 |
JPH08214197A (ja) * | 1995-01-31 | 1996-08-20 | Sony Corp | 撮像装置及び撮像方法 |
JP2556831B2 (ja) | 1985-05-11 | 1996-11-27 | オリンパス光学工業株式会社 | 光学的ロ−パスフイルタ−及びこれを用いた撮像装置 |
JPH11183849A (ja) * | 1997-12-19 | 1999-07-09 | Sharp Corp | 可変空間フィルタおよび撮像装置 |
JP2000333049A (ja) * | 1999-05-14 | 2000-11-30 | Sony Corp | 撮像装置 |
JP2003167123A (ja) * | 2001-11-30 | 2003-06-13 | Nikon Corp | 光学ローパスフィルタおよびカメラ |
JP2004156083A (ja) | 2002-11-05 | 2004-06-03 | Jfe Steel Kk | Rh脱ガス設備での酸素含有ガス上吹き装置および低炭素高マンガン鋼の精錬方法 |
JP2005208675A (ja) * | 2005-03-17 | 2005-08-04 | Olympus Corp | ズームレンズ |
WO2005117453A1 (ja) * | 2004-05-26 | 2005-12-08 | Acutelogic Corporation | 撮像装置 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH09261535A (ja) * | 1996-03-25 | 1997-10-03 | Sharp Corp | 撮像装置 |
US6250550B1 (en) * | 1999-06-14 | 2001-06-26 | International Business Machines Corporation | Automated media storage library with variable focal length lens |
US20040012710A1 (en) * | 2001-01-22 | 2004-01-22 | Tsuyoshi Yaji | Optical apparatus using deformable mirror |
US7266248B2 (en) * | 2003-08-08 | 2007-09-04 | Hewlett-Packard Development Company, L.P. | Method and apparatus for generating data representative of an image |
-
2007
- 2007-01-16 WO PCT/JP2007/050861 patent/WO2007083783A1/ja active Application Filing
- 2007-01-16 CN CNA2007800021491A patent/CN101366289A/zh active Pending
- 2007-01-16 KR KR1020087017569A patent/KR20080089601A/ko not_active Application Discontinuation
- 2007-01-16 EP EP07713665A patent/EP1978753A4/en not_active Withdrawn
- 2007-01-16 JP JP2007554995A patent/JP4558804B2/ja not_active Expired - Fee Related
- 2007-01-16 US US12/161,648 patent/US20090169126A1/en not_active Abandoned
- 2007-01-18 TW TW096101937A patent/TW200730880A/zh unknown
Patent Citations (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2556831B2 (ja) | 1985-05-11 | 1996-11-27 | オリンパス光学工業株式会社 | 光学的ロ−パスフイルタ−及びこれを用いた撮像装置 |
JPS6472119A (en) * | 1987-09-11 | 1989-03-17 | Canon Kk | Optical low-pass filter |
JPH06292093A (ja) | 1993-03-31 | 1994-10-18 | Sony Corp | 撮像装置 |
JPH08214197A (ja) * | 1995-01-31 | 1996-08-20 | Sony Corp | 撮像装置及び撮像方法 |
JPH11183849A (ja) * | 1997-12-19 | 1999-07-09 | Sharp Corp | 可変空間フィルタおよび撮像装置 |
JP2000333049A (ja) * | 1999-05-14 | 2000-11-30 | Sony Corp | 撮像装置 |
JP2003167123A (ja) * | 2001-11-30 | 2003-06-13 | Nikon Corp | 光学ローパスフィルタおよびカメラ |
JP2004156083A (ja) | 2002-11-05 | 2004-06-03 | Jfe Steel Kk | Rh脱ガス設備での酸素含有ガス上吹き装置および低炭素高マンガン鋼の精錬方法 |
WO2005117453A1 (ja) * | 2004-05-26 | 2005-12-08 | Acutelogic Corporation | 撮像装置 |
JP2005208675A (ja) * | 2005-03-17 | 2005-08-04 | Olympus Corp | ズームレンズ |
Non-Patent Citations (1)
Title |
---|
See also references of EP1978753A4 |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2011105581A1 (ja) * | 2010-02-26 | 2011-09-01 | 旭硝子株式会社 | 光学ローパスフィルタおよびデジタルカメラ |
JP2011232650A (ja) * | 2010-04-28 | 2011-11-17 | Asahi Glass Co Ltd | 光学ローパスフィルタ及びデジタルカメラ |
JP2012005044A (ja) * | 2010-06-21 | 2012-01-05 | Nikon Corp | ディジタルカメラ |
JP2012175449A (ja) * | 2011-02-22 | 2012-09-10 | Sony Corp | 撮像装置、撮像方法及び撮像制御プログラム |
JP2012225958A (ja) * | 2011-04-14 | 2012-11-15 | Asahi Glass Co Ltd | 光学ローパスフィルタおよび撮像機器 |
WO2015029388A2 (en) | 2013-08-28 | 2015-03-05 | Sony Corporation | Optical low pass filter, image pickup device, and image pickup apparatus |
JP2015046744A (ja) * | 2013-08-28 | 2015-03-12 | ソニー株式会社 | 光学的ローパスフィルタ、撮像デバイスおよび撮像装置 |
US10104273B2 (en) | 2013-08-28 | 2018-10-16 | Sony Corporation | Optical low pass filter, image pickup device, and image pickup apparatus |
CN108697308A (zh) * | 2016-03-09 | 2018-10-23 | 索尼公司 | 图像处理装置、图像处理方法和记录介质 |
CN108697308B (zh) * | 2016-03-09 | 2022-04-08 | 索尼公司 | 图像处理装置、图像处理方法和记录介质 |
JP2018004913A (ja) * | 2016-06-30 | 2018-01-11 | キヤノン株式会社 | 光学ローパスフィルタおよびそれを有する撮像装置、撮像ユニット |
Also Published As
Publication number | Publication date |
---|---|
EP1978753A4 (en) | 2012-07-04 |
US20090169126A1 (en) | 2009-07-02 |
TWI366680B (ja) | 2012-06-21 |
CN101366289A (zh) | 2009-02-11 |
TW200730880A (en) | 2007-08-16 |
JP4558804B2 (ja) | 2010-10-06 |
EP1978753A1 (en) | 2008-10-08 |
JPWO2007083783A1 (ja) | 2009-06-11 |
KR20080089601A (ko) | 2008-10-07 |
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