Optical device

Abstract

An optical device is provided, comprising: a lens system; an image sensor for receiving light passing through the lens system, wherein the image sensor is a merged image sensor capable of changing its pixel pitch; and a wavefront controller for deforming the wavefront of light entering the lens system, wherein the deformation pattern of the wavefront applied to the light changes according to the pixel pitch of the image sensor.

Description

Technical Field

[0001] The present invention relates to a method for reducing the moiré effect, an optical device capable of implementing the method, and a device having the optical device.

[0002] For example, the device can be a mobile phone, smartphone, tablet computer, personal computer, digital still camera, digital camera, surveillance camera, etc. Background Technology

[0003] Recent advancements in manufacturing technology have increased the number of pixels in image sensors installed in devices such as mobile phones, smartphones, tablets, personal computers, digital still cameras, digital cameras, or surveillance cameras.

[0004] In some cases, increasing the number of pixels can lead to a decrease in the pixel pitch of an image sensor, because the size of an image sensor that can be installed in a device is limited.

[0005] Reducing the pixel pitch of an image sensor may decrease its light-receiving sensitivity.

[0006] In this regard, merging sensors that can change their pixel pitch have recently attracted attention as a solution to improve light receiving sensitivity.

[0007] The characteristic of a merging sensor is that it combines pixel signals from neighboring pixels into a single result signal, thereby virtually combining multiple adjacent pixels into one pixel.

[0008] For example, there are horizontally integrated sensors, vertically integrated sensors, and fully integrated sensors.

[0009] Horizontal and vertical merging sensors can virtually combine a pair of adjacent pixels arranged in the row and column directions, respectively, and double their pixel spacing.

[0010] Furthermore, the fully integrated sensor can virtually combine adjacent N×N pixels arranged in a two-dimensional array and increase the pixel pitch by a factor of N, where N is set to be equal to or greater than 2.

[0011] For example, a merging operation that doubles the pixel spacing can be called a "2×2 merge".

[0012] However, increasing the pixel pitch can lead to the moiré effect in the generated image, as the moiré effect becomes more pronounced when capturing objects with spatial frequencies greater than the Nyquist frequency corresponding to the pixel pitch of the image sensor.

[0013] Although some traditional cameras are equipped with optical low-pass filters (OLPF) to reduce the moiré effect, the moiré effect is not effectively reduced when the pixel pitch of the image sensor changes because the cutoff frequency of a traditional OLPF is fixed. Summary of the Invention

[0014] The embodiments provide an optical device, a method for reducing the moiré effect, and an apparatus having the optical device.

[0015] The device can be a mobile phone, smartphone, tablet computer, personal computer, digital still camera, digital camera, surveillance camera, etc.

[0016] The first aspect of the embodiment provides the optical device.

[0017] In a first possible implementation of the first aspect, the optical device includes: a lens system; an image sensor for receiving light passing through the lens system, wherein the image sensor is a merged image sensor capable of changing its pixel pitch; and a wavefront controller for deforming the wavefront of light entering the lens system, wherein the deformation pattern of the wavefront applied to the light changes according to the pixel pitch of the image sensor.

[0018] Generally, a wavefront refers to a portion of a wave consisting of wave points originating from the same source and having the same optical length as the source.

[0019] Since the points on the wavefront have the same optical length, the wavefront forms an equiphase wavefront.

[0020] According to a first possible implementation of the first aspect, the wavefront of the light entering the lens system can be deformed to sufficiently reduce the modulation transfer function (MTF) curve of the optical device at a target spatial frequency related to the pixel pitch of the image sensor.

[0021] For example, the target spatial frequency could be the Nyquist frequency corresponding to the pixel pitch of the image sensor.

[0022] Reducing the MTF curve sufficiently at the corresponding target spatial frequency can reduce the Moiré effect that appears in images generated based on the output signal from the image sensor.

[0023] In a first possible implementation of the first aspect, even if the pixel pitch of the image sensor changes, the moiré effect can be effectively reduced by forming a wavefront that provides a suitable MTF curve related to the current pixel pitch of the image sensor.

[0024] A second possible implementation of the first aspect is provided: an optical device according to the first possible implementation of the first aspect, wherein the deformation pattern of the wavefront of the light applied is determined such that the MTF curve of the optical device is sufficiently reduced near the Nyquist frequency corresponding to the pixel spacing of the image sensor.

[0025] The Moiré effect becomes apparent when capturing objects whose spatial frequency is greater than the Nyquist frequency corresponding to the pixel spacing of the image sensor.

[0026] In a second possible implementation of the first aspect, by applying a suitable deformation pattern to the wavefront, the MTF curve of the optical device can be controlled to be sufficiently reduced near the Nyquist frequency corresponding to the pixel pitch of the image sensor, thereby effectively reducing the moiré effect even if the pixel pitch of the image sensor changes.

[0027] Optionally, the wavefront controller may be a phase control mask for delaying the phase of light passing through at least one deformable region of the phase control mask.

[0028] Phase control masks can be thin films, panels, sheets, etc., that have wavefront controller features.

[0029] In some exemplary implementations, the phase control mask may be an electrochromic device, an opto-wetting device, a liquid crystal (LC) delayer, etc.

[0030] These are exemplary elements that can be used as phase control masks, and it should be noted that this exemplary enumeration is not intended to be limiting.

[0031] Electrochromic devices can be solid-state electrochromic devices that use solid inorganic or organic materials such as Ta2O5 and ZrO2 as electrolytes, or laminated electrochromic devices that use liquid gel as electrolytes.

[0032] Electrochromic devices can be used to control optical properties, such as refraction, absorption, and reflectivity, by applying a voltage.

[0033] If an electrochromic device is used as a phase control mask, the electrochromic device controls the refraction of its target region to extend the optical length of light passing through the target region.

[0034] The extension of optical length leads to phase delay of light, and the phase delay leads to wavefront deformation of light.

[0035] Here, this target area is called the deformation region.

[0036] Wavefront deformation may lower the MTF curve, thereby reducing the moiré effect in the generated image.

[0037] Similarly, even when using photoelectrowetting devices as phase control masks, wavefront deformation can be mitigated, and the Moiré effect can be reduced by lowering the MTF curve near the target frequency (e.g., the Nyquist frequency).

[0038] Furthermore, even in the alternative case of using an LC delayer as a phase control mask, wavefront deformation can be mitigated, and the Mohr effect can be reduced by lowering the MTF curve near the target frequency.

[0039] The present invention is not limited to these exemplary cases, and other modified examples are also applicable.

[0040] A third possible implementation of the first aspect is provided: an optical device according to a second possible implementation of the first aspect, wherein the phase control mask is divided into a plurality of annular regions centered on the optical axis of the lens system, and each annular region and a region within the innermost annular region can be the deformable region or the non-deformable region.

[0041] For example, each annular region can be a circle.

[0042] In a third possible implementation of the first aspect, each deformable region has an axisymmetric shape centered on the optical axis of the lens system, and various circular stripe patterns can be achieved by controlling the voltage applied to at least a portion of the annular region and / or the region within the innermost annular region.

[0043] The target frequency at which the MTF curve of the optical device is sufficiently reduced can be finely controlled by switching between circular stripe patterns on the phase control mask according to the pixel pitch of the image sensor.

[0044] The second aspect of this embodiment provides a method for reducing the Mohr effect.

[0045] In a first possible implementation of the second aspect, the method includes: a wavefront controller causing wavefront deformation of light entering a lens system, wherein the deformation pattern of the wavefront applied to the light is changed according to the pixel pitch of an image sensor, the image sensor being a fused image sensor capable of changing its pixel pitch; the image sensor receiving light passing through the lens system.

[0046] According to the first possible implementation of the second aspect, the wavefront of the light entering the lens system can be deformed to sufficiently reduce the modulation transfer function (MTF) curve of the optical device at a target spatial frequency related to the pixel pitch of the image sensor.

[0047] For example, the target spatial frequency could be the Nyquist frequency corresponding to the pixel pitch of the image sensor.

[0048] Reducing the MTF curve sufficiently at the corresponding target spatial frequency can reduce the Moiré effect that appears in images generated based on the output signal from the image sensor.

[0049] In the first possible implementation of the second aspect, even if the pixel pitch of the image sensor changes, the moiré effect can be effectively reduced by forming a wavefront that provides a suitable MTF curve related to the current pixel pitch of the image sensor.

[0050] A second possible implementation of the second aspect is provided: the method according to the first possible implementation of the second aspect, wherein the deformation pattern of the wavefront of the light applied is determined such that the MTF curve of the optical device including the wavefront controller and the lens system is sufficiently reduced near the Nyquist frequency corresponding to the pixel spacing of the image sensor.

[0051] As mentioned above, the Moiré effect becomes apparent when capturing objects with spatial frequencies greater than the Nyquist frequency corresponding to the pixel spacing of the image sensor.

[0052] In a second possible implementation of the first aspect, by applying a suitable deformation pattern to the wavefront, the MTF curve of the optical device can be controlled to be sufficiently reduced near the Nyquist frequency corresponding to the pixel pitch of the image sensor, thereby effectively reducing the moiré effect even if the pixel pitch of the image sensor changes.

[0053] Optionally, the wavefront controller may be a phase control mask for delaying the phase of light passing through at least one deformable region of the phase control mask.

[0054] Phase control masks can be thin films, panels, sheets, etc., that have wavefront controller features.

[0055] In some exemplary implementations, the phase control mask may be an electrochromic device, a photowetting device, an LC delayer, etc.

[0056] These are exemplary elements that can be used as phase control masks, and it should be noted that this exemplary enumeration is not intended to be limiting.

[0057] Electrochromic devices can be solid-state electrochromic devices that use solid inorganic or organic materials such as Ta2O5 and ZrO2 as electrolytes, or laminated electrochromic devices that use liquid gel as electrolytes.

[0058] Electrochromic devices can be used to control optical properties, such as refraction, absorption, and reflectivity, by applying a voltage.

[0059] If an electrochromic device is used as a phase control mask, the electrochromic device controls the refraction of its target region to extend the optical length of light passing through the target region.

[0060] The extension of optical length leads to phase delay of light, and the phase delay leads to wavefront deformation of light.

[0061] Here, this target area is called the deformation region.

[0062] Wavefront deformation may lower the MTF curve, thereby reducing the moiré effect in the generated image.

[0063] Similarly, even when using photoelectrowetting devices as phase control masks, wavefront deformation can be mitigated, and the Moiré effect can be reduced by lowering the MTF curve near the target frequency (e.g., the Nyquist frequency).

[0064] Furthermore, even in the alternative case of using an LC delayer as a phase control mask, wavefront deformation can be mitigated, and the Mohr effect can be reduced by lowering the MTF curve near the target frequency.

[0065] The present invention is not limited to these exemplary cases, and other modified examples are also applicable.

[0066] A third possible implementation of the second aspect is provided: the method according to the second possible implementation of the second aspect, wherein the phase control mask is divided into a plurality of annular regions centered on the optical axis of the lens system, and each annular region and the region within the innermost annular region can be the deformable region or the non-deformable region.

[0067] For example, each annular region can be a circle.

[0068] In a third possible implementation of the second aspect, each deformable region has an axisymmetric shape centered on the optical axis of the lens system, and various circular stripe patterns can be achieved by controlling the voltage applied to at least a portion of the annular region and / or the region within the innermost annular region.

[0069] The target frequency at which the MTF curve of the optical device is sufficiently reduced can be finely controlled by switching between circular stripe patterns on the phase control mask according to the pixel pitch of the image sensor.

[0070] A third aspect of this embodiment provides an apparatus comprising: an optical device according to any one of the first to third possible implementations of the first aspect; and a processor for generating an image based on an output signal from the image sensor, and storing the image in a memory.

[0071] The fourth aspect of this embodiment provides a program that causes a computer to perform the method according to any one of the first to third possible implementations of the second aspect.

[0072] The fifth aspect of this embodiment provides a non-transitory computer-readable storage medium storing a program that enables a computer to execute the method described in any of the first to third possible implementations of the second aspect. Attached Figure Description

[0073] Figure 1 This is a schematic block diagram used to describe the configuration of the device and optical devices in the device provided in the embodiments of the present invention.

[0074] Figure 2 This is a schematic diagram illustrating the arrangement of the wavefront (WF) controller and lens group in the optical device provided by an embodiment of the present invention.

[0075] Figure 3 This is a schematic diagram illustrating the controllable area of ​​the WF controller provided in an embodiment of the present invention.

[0076] Figure 4 A first example of the deformable region of a WF controller provided by an embodiment of the present invention is shown.

[0077] Figure 5 A second example of the deformable region of the WF controller provided by an embodiment of the present invention is shown.

[0078] Figure 6 A third example of a deformable region of a WF controller provided by an embodiment of the present invention is shown.

[0079] Figure 7 A fourth example of a deformable region of a WF controller provided by an embodiment of the present invention is shown.

[0080] Figure 8 A fifth example of a deformable region of a WF controller provided by an embodiment of the present invention is shown.

[0081] Figure 9A sixth example of a deformable region of a WF controller provided by an embodiment of the present invention is shown.

[0082] Figure 10 A first example of a modulation transfer function (MTF) curve of an optical device provided by an embodiment of the present invention is shown.

[0083] Figure 11 A second example of the MTF curve of an optical device provided by an embodiment of the present invention is shown.

[0084] Figure 12 A third example of the MTF curve of an optical device provided in an embodiment of the present invention is shown.

[0085] Figure 13 A fourth example of the MTF curve of an optical device provided in an embodiment of the present invention is shown.

[0086] Figure 14A A first exemplary variant of the WF controller provided by an embodiment of the present invention is shown. Figure 14B The MTF curve of an optical device including a WF controller associated with a first exemplary variant is shown.

[0087] Figure 15A A second exemplary variant of the WF controller provided by an embodiment of the present invention is shown. Figure 15B The MTF curve of an optical device including a WF controller associated with a second exemplary variant is shown.

[0088] Figure 16 A flowchart is shown to describe a method implemented by a device according to an embodiment of the present invention. Detailed Implementation

[0089] The technical solutions of the embodiments are described below with reference to the accompanying drawings.

[0090] It is understood that the embodiments described below are not all embodiments, but only some embodiments related to the present invention.

[0091] It should be noted that, without any inventive effort, those skilled in the art can derive other embodiments based on the embodiments described below, which are within the scope of protection of this invention.

[0092] The embodiments described below relate to a method for reducing the moiré effect, an optical device for implementing the method, and a device having the optical device.

[0093] The embodiments described below can be applied to various devices, such as mobile phones, smartphones, tablets, personal computers, digital still cameras, digital cameras, and surveillance cameras.

[0094] (Exemplary configurations of optical devices and apparatuses) are described below in conjunction with Figure 1 The configuration of the optical device and apparatus provided in the embodiments of the present invention is described.

[0095] Figure 1 This is a schematic block diagram used to describe the configuration of the device and optical devices in the device provided in the embodiments of the present invention.

[0096] Figure 1 The device 10 shown is an example of a device provided in an embodiment of the present invention.

[0097] like Figure 1 As shown, device 10 includes a wavefront (WF) controller 11, a lens system 12, an image sensor 13, a processor 14, and a memory 15.

[0098] Optionally, the device 10 may also include at least one dedicated controller for controlling the operation of the WF controller 11 and / or the image sensor 13.

[0099] The WF controller 11, lens system 12, and image sensor 13 can form the optical device provided in the embodiments of the present invention.

[0100] For example, the WF controller 11 can operate as a phase control mask to deform the wavefront of light entering the lens system 12. The phase control mask can be an electrochromic (EC) device, an opto-wetting (OEW) device, a liquid crystal (LC) delayer, etc.

[0101] These are exemplary elements that can be used as phase control masks, and it should be noted that the exemplary enumeration is not intended to be limiting.

[0102] The lens system 12 includes at least one lens group, an aperture stop, and an optical filter such as an infrared (IR) cutoff filter.

[0103] For example, lens system 12 can have Figure 2 The structure shown.

[0104] Figure 2 This is a schematic diagram illustrating the arrangement of the WF controller and lens group in the optical device provided in an embodiment of the present invention.

[0105] exist Figure 2 In one example, the lens system 12 includes an aperture stop ST and lenses L1 to L7, and the WF controller 11 is located on the object side of the lens system 12.

[0106] exist Figure 2 In the middle, the Z direction corresponds to the optical axis AX of the lens system 12, and the surface of the WF controller 11 is perpendicular to the Z direction and corresponds to the XY plane.

[0107] Figure 2 In this context, OP1 and OP2 represent optical paths that are symmetrical with respect to the optical axis AX.

[0108] Image sensor 13 can be a charge-coupled device (CCD) image sensor, a complementary metal-oxide-semiconductor (CMOS) image sensor, etc.

[0109] Image sensor 13 is a fused image sensor capable of changing its pixel pitch.

[0110] In addition, the image sensor 13 is used to receive light passing through the lens system 12.

[0111] The processor 14 is used to generate an image based on the output signal from the image sensor 13, and to store the image in the memory 15.

[0112] For example, processor 14 can be a central processing unit (CPU), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a graphics processing unit (GPU), etc.

[0113] The memory 15 can be a read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), solid state drive (SSD), portable storage media, etc.

[0114] In addition, memory 15 may store programs to enable processor 14 to perform operations for controlling at least one of WF controller 11, lens system 12 and image sensor 13.

[0115] The program can be provided to device 10 via data carrying methods (e.g., non-transitory computer-readable storage media, local area networks and / or wide area networks, etc.).

[0116] In an embodiment of the present invention, the WF controller 11 is used to deform the wavefront of light entering the lens system 12.

[0117] Specifically, the WF controller 11 can delay the phase of light passing through at least one of its controllable deformation regions and deform the wavefront of light entering the lens system 12.

[0118] Generally, a wavefront refers to a portion of a wave consisting of wave points originating from the same source and having the same optical length as the source.

[0119] Since the points on the wavefront have the same optical length, the wavefront forms an equiphase wavefront.

[0120] In some exemplary implementations, the WF controller 11 may be an electrochromic (EC) device, an opto-wetting device, a liquid crystal (LC) delayer, etc.

[0121] These are exemplary components that can be used as the WF controller 11, and it should be noted that this exemplary enumeration is not intended to be limiting.

[0122] EC devices can be solid-state electrochromic devices that use solid inorganic or organic materials such as Ta2O5 and ZrO2 as electrolytes, or laminated electrochromic devices that use liquid gel as electrolytes.

[0123] EC devices can be used to control optical properties such as refraction, absorption, and reflectivity by applying a voltage.

[0124] If an EC device is used as a phase control mask, the EC device controls the refraction of its target region to extend the optical length of light passing through the target region.

[0125] The extension of optical length leads to phase delay of light, and the phase delay leads to wavefront deformation of light.

[0126] This target area is the deformable area mentioned above.

[0127] Wavefront deformation may reduce the modulation transfer function (MTF) curve of the optical device, thereby reducing the moiré effect in the generated image.

[0128] Similarly, even when using an opto-wetting device as the WF controller 11, wavefront deformation can be reduced, and the moiré effect can be mitigated by lowering the MTF curve near the target frequency (e.g., the Nyquist frequency associated with the pixel pitch of the image sensor 13).

[0129] Furthermore, even when using an LC delayer as another WF controller 11, wavefront deformation can be reduced, and the Mohr effect can be decreased by lowering the MTF curve near the target frequency.

[0130] The present invention is not limited to these exemplary cases, and other modified examples are also applicable.

[0131] The WF controller 11 is controlled to change the deformation pattern of the wavefront applied to the light according to the pixel pitch of the image sensor 13.

[0132] For example, the deformation pattern of the wavefront applied to the light can be determined such that the MTF curve of the optical device can be sufficiently reduced near the Nyquist frequency corresponding to the pixel pitch of the image sensor 13.

[0133] Typically, the Moiré effect becomes apparent when capturing objects with spatial frequencies greater than the Nyquist frequency corresponding to the pixel spacing of the image sensor used for capture.

[0134] In an embodiment of the invention, the wavefront of light entering the lens system 12 can be deformed by using a deformation pattern suitable for sufficiently reducing the MTF curve of the optical device near the Nyquist frequency corresponding to the pixel pitch of the image sensor 13.

[0135] Even if the pixel pitch of the image sensor 13 changes, this can reduce the moiré effect that appears in the generated image.

[0136] (Methods for controlling the shape of deformable regions) are described below. Figure 3 Describe a method for controlling the shape of the deformable region.

[0137] Figure 3 This is a schematic diagram illustrating the controllable area of ​​the WF controller provided in an embodiment of the present invention.

[0138] Figure 3 This is just one of the exemplary cases shown in this embodiment, and it should be noted that the present invention is not limited to these exemplary cases, and other modified examples are also applicable.

[0139] like Figure 3 As shown, the WF controller 11 can be divided into annular regions A2 to A7 centered on the optical axis of the lens system 12, and region A1 within the innermost annular region A2.

[0140] Optionally, the number of regions in the WF controller 11 can be equal to or greater than 8, or equal to or less than 6.

[0141] To simplify the explanation, the following text will use... Figure 3 The exemplary cases shown are described below.

[0142] Each region in A1 to A7 can be a deformable region or a non-deformable region.

[0143] For example, the region where a predetermined voltage is applied to the WF controller 11 operates as a deformable region, while another region of the WF controller 11 where no voltage is applied operates as a non-deformable region.

[0144] The phase of light passing through the deformed region is delayed, while the phase of light passing through the undeformed region is maintained.

[0145] exist Figure 3 In the example, each deformable region has an axisymmetric shape centered on the optical axis of the lens system 12.

[0146] In this case, various circular stripe patterns can be achieved by controlling the voltage applied to at least a portion of the annular region and / or a region within the innermost annular region, such as... Figures 4 to 9 As shown.

[0147] Figures 4 to 9 An example of the deformable region of the WF controller provided by an embodiment of the present invention is shown.

[0148] Figure 4 The example shows that regions A1, A3, A5, and A7 are set as deformable regions, while the remaining regions A2, A4, and A6 are set as non-deformable regions.

[0149] In this example, the light passing through regions A1, A3, A5, and A7 is delayed in phase by λ / 2, where λ represents the wavelength of the light.

[0150] Optionally, the phase delay of light passing through the deformed region can be set to other values, such as π / 2, π / 4, π / 5, 3π / 4, etc.

[0151] Determine the phase delay occurring in the deformable region so as to sufficiently reduce the MTF curve at the target spatial frequency associated with the merging type (e.g., 2×2 merging, 4×4 merging, etc.).

[0152] In this regard, since the frequency at which the MTF curve is sufficiently reduced depends on the shape of the deformed region, it is preferable to determine the phase delay by taking into account the shape of the deformed region so that the MTF curve is sufficiently reduced at the target frequency.

[0153] To simplify the explanation, an example with a phase delay of λ / 2 is described below.

[0154] Here, the configuration of regions A1 to A7 is represented by vectors (x1, x2, x3, x4, x5, x6, x7) to simplify the explanation, where x1 to x7 represent the phase delay of the light passing through regions A1 to A7, respectively.

[0155] For example, in Figure 4 In the example, the configuration of regions A1 to A7 is represented by (λ / 2,0,λ / 2,0,λ / 2,0,λ / 2).

[0156] In this example, the light passing through regions A1, A3, A5, and A7 is delayed in phase by λ / 2.

[0157] Figure 5 The example shows that regions A1, A4, and A6 are set as deformable regions, while the remaining regions A2, A3, A5, and A7 are set as non-deformable regions.

[0158] In this example, the configuration of regions A1 to A7 is represented by (λ / 2,0,0,λ / 2,0,λ / 2,0), and the light passing through regions A1, A4, and A6 is delayed in phase by λ / 2.

[0159] Figure 6 The example shows that regions A2, A5, and A7 are set as deformable regions, while the remaining regions A1, A3, A4, and A6 are set as non-deformable regions.

[0160] In this example, the configuration of regions A1 to A7 is represented by (0,λ / 2,0,0,λ / 2,0,λ / 2), and the light passing through regions A2, A5, and A7 is delayed in phase by λ / 2.

[0161] Figure 7 The example shows that each of regions A2, A4, and A6 is set as a deformable region, while the remaining regions A1, A3, A5, and A7 are set as non-deformable regions.

[0162] In this example, the configuration of regions A1 to A7 is represented by (λ / 2,0,0,λ / 2,0,λ / 2,0), and the light passing through regions A2, A4, and A6 is delayed in phase by λ / 2.

[0163] Figure 8 The example shows that each of the regions A1-A3 and A6 is set as a deformable region, while the remaining regions A4, A5 and A7 are set as non-deformable regions.

[0164] In this example, the configuration of regions A1 to A7 is represented by (λ / 2,λ / 2,λ / 2,0,0,λ / 2,0), and the light passing through regions A1-A3 and A6 is delayed in phase by λ / 2.

[0165] Figure 9 The example shows that each of regions A2-A3 and A5-A6 is set as a deformable region, while the remaining regions A4 and A7 are set as non-deformable regions.

[0166] In this example, the configuration of regions A1 to A7 is represented by (λ / 2,λ / 2,λ / 2,0,λ / 2,λ / 2,0), and the light passing through regions A2-A3 and A5-A6 is delayed in phase by λ / 2.

[0167] As described above, the various shapes of the deformation area of ​​the WF controller can be achieved by changing the combination of areas set in the deformation area between areas A1 to A7.

[0168] The MTF curve of an optical device can be changed according to the shape of the deformed region.

[0169] Therefore, device 10 can precisely control the MTF characteristics of the optical device.

[0170] For example, the processor 14 can control the WF controller 11 to form the shape of the deformation region corresponding to (λ / 2,0,λ / 2,0,λ / 2,0,λ / 2).

[0171] In this case, the MTF curve of the optical device is as follows: Figure 10 As shown.

[0172] Figure 10 An example of the MTF curve of an optical device provided by an embodiment of the present invention is shown.

[0173] exist Figure 10 In the diagram, the horizontal axis represents the spatial frequency (period / mm) of the image sensor 13, and the vertical axis represents the amplitude of the modulation.

[0174] Furthermore, the solid curve represents the MTF curve under the condition of (λ / 2,0,λ / 2,0,λ / 2,0,λ / 2), and the dashed dotted curve represents the reference level corresponding to the conditions under which the WF controller 11 maintains the wavefront of the light before and after passing through the WF controller.

[0175] Connect entity curves with Figure 10 The results show that the MTF curve in the case of (λ / 2,0,λ / 2,0,λ / 2,0,λ / 2) drops sufficiently at about 200 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 2×2 merging.

[0176] This reduces the moiré effect when the pixel pitch of the image sensor 13 is 2×2 combined.

[0177] Similarly, the processor 14 can control the WF controller 11 to form the shape of the deformation region corresponding to (λ / 2,0,λ / 2,λ / 2,0,λ / 2,0).

[0178] In this case, the MTF curve of the optical device is as follows: Figure 11 As shown.

[0179] Figure 11 An example of the MTF curve of an optical device provided by an embodiment of the present invention is shown.

[0180] exist Figure 11 In the diagram, the horizontal axis represents the spatial frequency (period / mm) of the image sensor 13, and the vertical axis represents the amplitude of the modulation.

[0181] Furthermore, the solid curve represents the MTF curve under the condition of (λ / 2,0,λ / 2,λ / 2,0,λ / 2,0), and the dashed dot curve represents the reference level corresponding to the conditions under which the WF controller 11 maintains the wavefront of the light before and after passing through the WF controller.

[0182] Connect entity curves with Figure 11 Comparing the dashed point curves in the figure, the results show that the MTF curve in the case of (λ / 2,0,λ / 2,λ / 2,0,λ / 2,0) drops sufficiently at about 200 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 2×2 merged.

[0183] Furthermore, the MTF curve drops sufficiently at approximately 100 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 4×4 merging.

[0184] This reduces the moiré effect when the pixel pitch of the image sensor 13 is 2×2 merging and 4×4 merging.

[0185] Furthermore, the processor 14 can control the WF controller 11 to form the shape of the deformation region corresponding to (λ / 2,0,0,λ / 2,0,λ / 2,0).

[0186] In this case, the MTF curve of the optical device is as follows: Figure 12 As shown.

[0187] Figure 12 An example of the MTF curve of an optical device provided by an embodiment of the present invention is shown.

[0188] exist Figure 12 In the diagram, the horizontal axis represents the spatial frequency (period / mm) of the image sensor 13, and the vertical axis represents the amplitude of the modulation.

[0189] Furthermore, the solid curve represents the MTF curve under the condition of (λ / 2,0,0,λ / 2,0,λ / 2,0), and the dashed dot curve represents the reference level corresponding to the conditions under which the WF controller 11 maintains the wavefront of the light before and after passing through the WF controller.

[0190] Connect entity curves with Figure 12 The results show that the MTF curve in the case of (λ / 2,0,0,λ / 2,0,λ / 2,0) drops sufficiently at about 200 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 2×2 merged.

[0191] Furthermore, the MTF curve drops sufficiently at approximately 100 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 4×4 merging.

[0192] This reduces the moiré effect when the pixel pitch of the image sensor 13 is 2×2 merging and 4×4 merging.

[0193] Furthermore, the processor 14 can control the WF controller 11 to form the shape of the deformation region corresponding to (0,0,0,0,λ / 2,0,λ / 2).

[0194] In this case, the MTF curve of the optical device is as follows: Figure 13 As shown.

[0195] Figure 13 An example of the MTF curve of an optical device provided by an embodiment of the present invention is shown.

[0196] exist Figure 13 In the diagram, the horizontal axis represents the spatial frequency (period / mm) of the image sensor 13, and the vertical axis represents the amplitude of the modulation.

[0197] Furthermore, the solid curve represents the MTF curve under the condition of (0,0,0,0,λ / 2,0,λ / 2), and the dashed dot curve represents the reference level corresponding to the conditions under which the WF controller 11 maintains the wavefront of the light before and after passing through the WF controller.

[0198] Connect entity curves with Figure 13 The results show that the MTF curve in the case of (0,0,0,0,λ / 2,0,λ / 2) drops sufficiently at about 200 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 2×2 merged.

[0199] This reduces the moiré effect when the pixel pitch of the image sensor 13 is 2×2 combined.

[0200] As described above, the WF controller 11 can change the shape of its deformable region to any shape that can be formed by combining the division of regions A1 to A7.

[0201] Therefore, the processor 14 can determine the appropriate shape of the deformation region of the WF controller 11 based on the merging type of the image sensor 13.

[0202] This allows for effective reduction of the moiré effect even if the pixel pitch of the image sensor 13 changes.

[0203] (Variant) See below for reference. Figure 14A , Figure 14B , Figure 15A and Figure 15B Describe the WF controller 11 and the variation of the deformation pattern.

[0204] Figure 14A and Figure 15A An exemplary deformation of the deformable pattern provided by an embodiment of the present invention is shown.

[0205] Figure 14B and Figure 15B The MTF curve of an optical device using a WF controller associated with an exemplary variant is shown.

[0206] As described above, the partitioned regions in the WF controller 11 can be constructed according to the implementation method adopted.

[0207] In the variant described herein, the WF controller 11 has Figure 14A and Figure 15A The ten divisions shown.

[0208] Each partitioned region can be either a deformable region or a non-deformable region.

[0209] Furthermore, the phase delay of the region that divides the deformation area is set to λ / 2 or λ, where λ represents the wavelength of the incident light.

[0210] Here, the innermost region is A1, and the outer regions of A1 are A2, A3, ..., A10 arranged in sequence.

[0211] exist Figure 14A In the example, each of regions A1, A3, A5, and A6 is set as a deformable region, while the remaining regions A2, A4, and A7-A10 are set as non-deformable regions.

[0212] In this example, the light passing through regions A1, A3, and A6 is delayed in phase by λ / 2, and the light passing through region A5 is delayed in phase by λ.

[0213] In this example, the configuration of regions A1 to A10 is represented by (λ / 2,0,λ / 2,0,λ,λ / 2,0,0,0,0), obtaining... Figure 14B The MTF curve shown.

[0214] Connect entity curves with Figure 14B Comparing the dashed point curves in the figure, the results show that the MTF curve in the case of (λ / 2,0,λ / 2,0,λ,λ / 2,0,0,0,0) drops sufficiently at about 200 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 2×2 merged.

[0215] Furthermore, the MTF curve decreases at approximately 100 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 4×4 combined.

[0216] This reduces the moiré effect when the pixel pitch of the image sensor 13 is 2×2 merging and 4×4 merging.

[0217] exist Figure 15A In the example, each of the regions A3-A6 and A8-A9 is set as a deformable region, while the remaining regions A1-A2, A7 and A10 are set as non-deformable regions.

[0218] In this example, the light passing through regions A3-A4 and A8-A9 is delayed in phase by λ / 2, and the light passing through region A5-A6 is delayed in phase by λ.

[0219] In this example, the configuration of regions A1 to A10 is represented by (0,0,λ / 2,λ / 2,λ,λ,0,λ / 2,λ / 2,0), obtaining Figure 15B The MTF curve shown.

[0220] Connect entity curves with Figure 15B Comparing the dashed point curves in the figure, the results show that the MTF curve in the case of (0,0,λ / 2,λ / 2,λ,λ,0,λ / 2,λ / 2,0) drops sufficiently at about 200 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 2×2 combined.

[0221] Furthermore, the MTF curve drops sufficiently at approximately 100 on the horizontal axis, which is the Nyquist frequency when the pixel pitch of the image sensor 13 is 4×4 merging.

[0222] This reduces the moiré effect when the pixel pitch of the image sensor 13 is 2×2 merging and 4×4 merging.

[0223] (Equipment Operation) See below for reference. Figure 16 Describe the operation of device 10.

[0224] Figure 16 A flowchart is shown to describe a method implemented by a device according to an embodiment of the present invention.

[0225] In step S101, the WF controller 11 deforms the wavefront of the light entering the lens system 12, wherein the deformation pattern applied to the wavefront of the light is changed according to the pixel pitch of the image sensor 13, which is a fused image sensor capable of changing its pixel pitch.

[0226] In step S102, the image sensor 13 receives the light that has passed through the lens system 12.

[0227] In step S103, the processor 14 generates an image based on the output signal from the image sensor 13.

[0228] In step S104, the processor 14 determines whether to perform the merging of the image sensor 13.

[0229] For example, processor 14 can determine whether it has received an instruction to perform merging of image sensors 13.

[0230] If processor 14 receives an instruction to perform a merge, the process proceeds to step S105.

[0231] If processor 14 does not receive an instruction to perform the merge, the process proceeds to step S101.

[0232] In step S105, the processor 14 controls the image sensor 13 to change its pixel pitch.

[0233] For example, when processor 14 receives an instruction to perform a 2×2 merging, processor 14 controls image sensor 13 to combine each set of four adjacent pixels into a virtual set of pixels to change the pixel spacing.

[0234] Furthermore, when the processor 14 receives an instruction to perform 4×4 merging, the processor 14 controls the image sensor 13 to combine each set of 16 adjacent pixels into a virtual set of pixels to change the pixel spacing.

[0235] In step S106, the processor 14 controls the WF controller 11 to change its deformed region to a deformed region corresponding to the current pixel pitch of the image sensor 13.

[0236] For example, when the pixel pitch of the image sensor 13 is the pixel pitch in the case of 2×2 merging, the processor 14 controls the WF controller 11 to set a deformation pattern suitable for the changed pixel pitch, such as (λ / 2,0,λ / 2,0,λ / 2,0,λ / 2).

[0237] Furthermore, when the pixel pitch of the image sensor 13 is in the case of 4×4 pixel binning, the processor 14 controls the WF controller 11 to set a deformation pattern suitable for the changed pixel pitch, such as (λ / 2,0,λ / 2,λ / 2,0,λ / 2,0).

[0238] After the processing in step S106 is completed, the process proceeds to step S101.

[0239] according to Figure 16 The method shown can deform the wavefront of light entering the lens system 12 according to the pixel pitch of the image sensor 13, thereby sufficiently reducing the MTF curve of the optics at the Nyquist frequency associated with the current pixel pitch.

[0240] Reducing the MTF curve sufficiently at the Nyquist frequency can reduce the moiré effect appearing in the generated image.

[0241] Therefore, even if the pixel pitch of the image sensor 13 changes, the moiré effect can be effectively reduced.

[0242] The above disclosure only provides exemplary embodiments and is not intended to limit the scope of protection of this invention.

[0243] Those skilled in the art will understand that the above embodiments, as well as all or part of other embodiments and modifications that can be deduced based on the scope of the claims of this invention, are within the scope of this invention.

Claims

1. An optical device, characterized in that, include: Lens system; An image sensor for receiving light through the lens system, wherein the image sensor is a merging image sensor capable of changing its pixel pitch; A wavefront controller is used to deform the wavefront of light entering the lens system, wherein the deformation pattern of the wavefront applied to the light changes according to the pixel pitch of the image sensor. The wavefront controller is a phase control mask used to delay the phase of light passing through at least one deformable region of the phase control mask.

2. The optical device according to claim 1, characterized in that, The deformation pattern of the wavefront of the light applied is determined such that the modulation transfer function (MTF) curve of the optical device decreases near the Nyquist frequency corresponding to the pixel spacing of the image sensor.

3. The optical device according to claim 1, characterized in that, The phase control mask is an electrochromic device, an electrowetting device, or a liquid crystal delay device.

4. The optical device according to any one of claims 1 to 3, characterized in that, The phase control mask is divided into multiple annular regions centered on the optical axis of the lens system. Each annular region and the region within the innermost annular region can be either a deformable region or a non-deformable region.

5. A method for reducing the Mohr effect, characterized in that, include: A wavefront controller deforms the wavefront of light entering a lens system, wherein the deformation pattern of the wavefront applied to the light is changed according to the pixel pitch of an image sensor, the image sensor being a fused image sensor capable of changing its pixel pitch. The image sensor receives light passing through the lens system; Wherein, the wavefront controller is a phase control mask; The wavefront controller causes the wavefront deformation of light to include: delaying the phase of light passing through at least one deformable region of the phase control mask.

6. The method according to claim 5, characterized in that, The deformation pattern of the wavefront applied to the light is determined such that the modulation transfer function (MTF) curve of the optical device including the wavefront controller and the lens system decreases near the Nyquist frequency corresponding to the pixel spacing of the image sensor.

7. The method according to claim 5, characterized in that, The phase control mask is an electrochromic device, an electrowetting device, or a liquid crystal delay device.

8. The method according to any one of claims 5 to 7, characterized in that, The phase control mask is divided into multiple annular regions centered on the optical axis of the lens system, wherein each annular region and the region within the innermost annular region can be either a deformable region or a non-deformable region.

9. A shooting device, characterized in that, include: The optical device according to any one of claims 1 to 4; A processor is configured to generate an image based on the output signal from the image sensor, and to store the image in a memory.

10. A non-transitory computer-readable storage medium, characterized in that, The storage provides a program that enables a computer to execute the method according to any one of claims 5 to 8.

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