Optical instrument and method for controlling the same

Abstract

To provide an optical instrument that can dynamically obtain a soft focus effect without using a soft filter.SOLUTION: An optical instrument has: a first optical system and a second optical system that are arranged in parallel; a first focus lens that is provided in the first optical system and movable in an optical axis direction; a second focus lens that is provided in the second optical system and movable in the optical axis direction; and control means that controls the drive of the first and second focus lenses. The control means controls the drive so that the drive positions of the first and second focus lenses are at a focus position and a position separated from the focus position by a predetermined amount.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an optical instrument having two optical systems arranged side by side. [Background technology]

[0002] Conventionally, a configuration is known in which a lens can impart a blurring effect to the bokeh, which is different from the general characteristics that an aperture imparts to the bokeh (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-268437 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration of Patent Document 1, the light from one lens is split by a beam splitter and guided to two image sensors, and a focused image and an unfocused image are captured by each image sensor and then combined to obtain a soft focus effect. Therefore, an optical member must be inserted in one of the optical paths, and furthermore, the focus position during shooting is constant, and the soft focus amount cannot be dynamically adjusted.

[0005] An object of the present invention is to provide an optical device capable of dynamically obtaining a soft focus effect without using a soft filter. [Means for solving the problem]

[0006] An optical device according to one aspect of the present invention comprises a first optical system and a second optical system arranged in parallel, a first focus lens provided in the first optical system and movable in the optical axis direction, a second focus lens provided in the second optical system and movable in the optical axis direction, and a control means for controlling the driving of the first and second focus lenses, wherein the control means controls the driving so that the driving positions of the first and second focus lenses are respectively a focus position and a position away from the focus position by a predetermined amount. Effect of the Invention

[0007] According to the present invention, it is possible to provide an optical device capable of dynamically obtaining a soft focus effect without using a soft filter. [Brief description of the drawings]

[0008] [Figure 1] 1 is a block diagram of a camera system according to an embodiment of the present invention. [Diagram 2] 4 is a flowchart showing a process executed in capturing a moving image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same components, and duplicated descriptions will be omitted.

[0010] 1 is a block diagram of a camera system (imaging system) 10 according to an embodiment of the present invention. The camera system 10 has a lens device (hereinafter referred to as an interchangeable lens) 100 as an optical device, and an imaging device (hereinafter referred to as a camera body) 200 to which the interchangeable lens 100 is detachably and communicably attached.

[0011] The interchangeable lens 100 is a twin-lens type interchangeable lens having a first optical system 120a and a second optical system 120b arranged in parallel. The first optical system 120a includes a fixed front lens 101a, a variable magnification lens 102a, an aperture 103a, a correction lens 104a, and a focus lens 105a arranged in this order from the object side to the image side. Note that although each lens is composed of one lens element in FIG. 1, in reality each lens includes one or more lens elements.

[0012] The variable magnification lens 102a moves in the optical axis direction by rotating a zoom ring (not shown) provided on the interchangeable lens 100. This changes the interval between adjacent lens groups in the first optical system 120a, and the magnification is changed from the wide-angle end to the telephoto end. The variable magnification lens 102a may be driven in the optical axis direction by a zoom actuator such as a stepping motor or a DC motor.

[0013] The aperture 103a is driven by an aperture actuator 106a, which is composed of a stepping motor, a DC motor, or the like, to change its aperture diameter (aperture value). An aperture drive circuit 107a drives the aperture actuator 106a by supplying a drive signal to the aperture actuator 106a. The light amount adjustment unit 116a is composed of the aperture 103a, the aperture actuator 106a, and the aperture drive circuit 107a.

[0014] The correction lens 104a is driven in a shift direction perpendicular to the optical axis by an anti-vibration actuator 108a such as a stepping motor or a voice coil motor to correct camera shake. An anti-vibration drive circuit 109a supplies a drive signal to the anti-vibration actuator 108a. The anti-vibration unit 117a is composed of the correction lens 104a, the anti-vibration actuator 108a, and the anti-vibration drive circuit 109a.

[0015] The focus lens (first focus lens) 105a is driven by a focus actuator 110a including a stepping motor, a voice coil motor, a vibration motor, and the like, and is configured to be movable in the optical axis direction. Focus adjustment is performed by moving the focus lens 105a in the optical axis direction. The focus drive circuit 111a supplies a drive signal to the focus actuator 110a. The focus adjustment device 118a is configured by the focus lens 105a, the focus actuator 110a, and the focus drive circuit 111a.

[0016] The components of the second optical system 120b are denoted by the same reference characters as those of the components of the first optical system 120a, except that "a" is replaced by "b." Note that the focus lens 105b provided in the second optical system 120b and having the same function as the focus lens 105a corresponds to the second focus lens.

[0017] When the interchangeable lens 100 is attached to the camera body 200, an electrical contact (not shown) provided on the interchangeable lens 100 is connected to an electrical contact (not shown) provided on the camera body 200. In addition, communication contacts 113a, 113b, and 113c provided on the interchangeable lens 100 are respectively connected to communication contacts 207a, 207b, and 207c provided on the camera body 200. By connecting the power contacts, power is supplied to the interchangeable lens 100 from a secondary battery (not shown), such as a lithium ion battery, mounted on the camera body 200. By connecting the communication contacts, various information can be communicated between a lens control CPU (control means) 112 provided on the interchangeable lens 100 and a camera control CPU 206 provided on the camera body 200. Although FIG. 1 shows a case where three-wire serial communication is performed, communication may be performed using other communication methods.

[0018] The camera body 200 is provided with an imaging element 201 configured with a photoelectric conversion element such as a CCD sensor or a CMOS sensor. The imaging element 201 photoelectrically converts (captures) an optical image (subject image) formed by the first optical system 120a and the second optical system 120b on its imaging surface. Specifically, the light passing through the first optical system 120a forms an optical image in a region on the right side of the imaging element 201, and the light passing through the second optical system 120b forms an optical image in a region on the left side of the imaging element 201. This allows the imaging element 201 to capture two optical images without causing the lights passing through the first optical system 120a and the second optical system 120b to interfere with each other. The electric charges accumulated in the imaging element 201 are read out as analog imaging signals at a predetermined timing and input to the video signal processing circuit 202.

[0019] A video signal processing circuit 202 as an image processing means converts an analog imaging signal read out from the imaging element 201 into a digital imaging signal, and performs various signal processing such as amplification and gamma correction on the digital imaging signal to generate a digital video signal (moving image data). The digital video signal is output to a camera control CPU 206, a display device 205 constituted by a liquid crystal display panel or the like, and a storage device 204 constituted by an optical disk, a semiconductor memory, or the like.

[0020] An AF signal processing circuit 203 is provided within the video signal processing circuit 202. The AF signal processing circuit 203 extracts high frequency components and luminance components obtained from a group of pixels in an AF area, which is a focus detection region, from a digital imaging signal (or a digital video signal), and generates a focus evaluation value signal as focus information. The focus evaluation value signal indicates the contrast state (imaging contrast) of the image, that is, the sharpness, and changes with the movement of the focus lenses 105a, 105b. The focus position at which the value of the focus evaluation value signal, that is, the focus evaluation value, is maximum (peak) is the in-focus position in that AF area.

[0021] By providing the interchangeable lens 100 with a mechanism for changing the spherical aberration, it is possible to give a soft focus effect to the optical image. The spherical aberration is an aberration that occurs when light emitted from one point on the same optical axis does not converge to one point on the optical axis after passing through the lens. The spherical aberration has the effect of changing the contrast of the focused subject, that is, a soft focus effect. The soft focus effect has the characteristic of smoothing (blurring) the contour of the blurred subject image, and is an effect different from the effect that the aperture gives to the blur. For example, when the spherical aberration is increased, a part of the light beam converges in front of the focal plane, and the light beam of the back blur becomes wider. Therefore, even if the aperture diameter is the same, the back blur appears to be large and smooth. In this embodiment, it is possible to obtain a soft focus effect by acquiring a focused image and a defocused image using the optical images formed by the first optical system 120a and the second optical system 120b, and synthesizing the two images by the image synthesis processing circuit 209.

[0022] In addition, an image synthesis processing circuit 209 is provided in the video signal processing circuit 202. The image synthesis processing circuit 209 performs specific processing on the digital video signal obtained from the output of the image sensor 201 to convert it into a moving image corresponding to the VR180 video format with a field angle of 180°. The optical axis of the first optical system 120a and the optical axis of the second optical system 120b are separated from each other by the base line length in a direction perpendicular to them, and the video signal obtained through the first optical system 120a and the second optical system 120b has parallax. This parallax can be used to generate a VR180 moving image that allows stereoscopic viewing. By observing the VR180 moving image through an observation device such as a head-mounted display, the user can see a stereoscopic image.

[0023] The image synthesis processing circuit 209 can also convert a plurality of video signals obtained through the first optical system 120a and the second optical system 120b into video signals in the VR180 format separately and synthesize these video signals. This allows the image synthesis processing circuit 209 to obtain a VR180 moving image as the same video signal without parallax. For example, as described above, a soft focus moving image can be created by acquiring a focused image and an unfocused image using the optical images formed by the first optical system 120a and the second optical system 120b, and synthesizing the two images by the image synthesis processing circuit 209. In this embodiment, the soft focus moving image can be created during or after shooting.

[0024] The camera control CPU 206 includes an ISO sensitivity adjustment unit 210. The ISO sensitivity adjustment unit 210 is implemented in the camera control CPU 206 and determines the ISO sensitivity. The ISO sensitivity adjustment unit 210 determines the ISO sensitivity based on the output value of a photometry unit (AE) (not shown) that measures the amount of light received from a subject.

[0025] The operation unit 208 is composed of operation members such as a plurality of buttons and dials. By pressing a button or rotating a dial, the ISO sensitivity, shutter speed, and aperture value that determine the exposure conditions during image capture can be set. In addition, the camera body 200 is provided with operation members for setting the image capture mode, issuing image capture instructions, and the like.

[0026] 2 is a flowchart showing the process (control method) executed by the lens control CPU 112 in capturing a moving image. The lens control CPU 112 executes this process according to a computer program. Note that, in this embodiment, a case will be described in which the lens control CPU 112 of the interchangeable lens 100 executes the process, but the same process may also be executed by a CPU of a lens-integrated imaging device (optical equipment). In other words, this embodiment includes not only a lens device but also a lens-integrated imaging device.

[0027] In step S101, the lens control CPU 112 communicates with the camera control CPU 206 and receives information on the first and second drive amounts of the focus lens. The first and second drive amounts are drive amounts for driving either the focus lens 105a or 105b, and which one is to be assigned is determined in step S102. The information on the second drive amount may be the second drive amount itself, or may be the difference (predetermined amount) between the drive amounts of the two focus lenses. In the following description, it is assumed that the first drive amount itself is received as information on the first drive amount, and the difference from the first drive amount is received as the second drive amount.

[0028] In addition, the larger the difference between the drive amounts of the two focus lenses, the larger the amount of focus shift between the two optical images formed by the first optical system 120a and the second optical system 120b, and the larger the blur of the image obtained after synthesis. Therefore, the difference between the drive amounts of the two focus lenses is proportional to the amount of soft focus effect in the moving image obtained after synthesis.

[0029] In step S102, the lens control CPU 112 determines to which of the focus lenses 105a and 105b the first and second driving amounts are to be allocated.

[0030] In step S103, the lens control CPU 112 calculates a drive pulse for driving the focus lens 105a. In order to obtain a soft-focus moving image by subsequent synthesis, the drive position of the focus lens 105a is calculated to be the in-focus position.

[0031] In step S104, the lens control CPU 112 calculates a drive pulse for driving the focus lens 105b. When the drive position of the focus lens 105a is controlled to be the in-focus position as described above, the drive position of the focus lens 105b is calculated to be a non-focused position (a position away from the in-focus position by a predetermined amount).

[0032] In the process of steps S103 and S104, the calculation of the drive pulse is expressed assuming a stepping motor, but the present invention is not limited to this. It is sufficient to calculate the control signal to be supplied from the lens control CPU 112 to the focus drive circuits 111a and 111b in order to drive each focus lens by a predetermined drive amount.

[0033] In step S105, the lens control CPU 112 drives the focus lenses 105a and 105b. Specifically, the drive pulses calculated in the processes of steps S103 and S104 are supplied to the focus drive circuits 111a and 111b, respectively, to drive the focus actuators 110a and 110b, and the drive positions of the focus lenses 105a and 105b are changed. In this way, the images obtained using the two optical images formed after passing through each focus lens are respectively an in-focus image and an out-of-focus image, as described above.

[0034] In step S106, the lens control CPU 112 communicates with the camera control CPU 206 and determines whether the first driving amount or the difference between the driving amounts of the two focus lenses has changed. If the lens control CPU 112 determines that the first driving amount or the difference between the driving amounts of the two focus lenses has changed, it executes the process of step S102. If the lens control CPU 112 determines that the first driving amount or the difference between the driving amounts of the two focus lenses has not changed, it executes the process of step S107.

[0035] The first drive amount or the difference between the drive amounts of the two focus lenses changes when, for example, the focus position of the subject changes during shooting or the user changes the setting of the soft focus effect amount. In the former case, the drive amounts of the focus lenses 105a and 105b change in the same manner, and the difference between the drive amounts of the focus lenses does not change. On the other hand, in the latter case, the difference between the drive amounts of the focus lenses changes.

[0036] Here, the effect of soft focus photography by changing the difference in the drive amount of each focus lens will be described. In this embodiment, the focal positions of two images are changed by making the drive amount of each focus lens have a difference without using a component such as a soft filter. Also, as described above, the soft focus effect amount is proportional to the difference in the drive amount of each focus lens. Unlike a soft filter that needs to be attached to the interchangeable lens 100, the difference in the drive amount of each focus lens can be changed even during video shooting. Therefore, in this embodiment, the soft focus effect amount can be dynamically changed, making it possible to express a variety of images compared to the conventional art.

[0037] In step S107, the lens control CPU 112 communicates with the camera control CPU 206 and determines whether or not the image capture is completed. If the lens control CPU 112 determines that the image capture is completed, it ends this flow, and if it determines that the image capture is not completed, it executes the process of step S106.

[0038] Through steps S106 and S107, the camera system 10 continues changing the drive amount of each focus lens in response to user operations until shooting is completed (during shooting).

[0039] According to the configuration of this embodiment, a focused image obtained from an optical image formed by the first optical system 120a and a defocused image obtained from an optical image formed by the second optical system 120b are synthesized by the image synthesis processing circuit 209 and converted into a soft focus image. Note that it is not necessary to make one of them the focused image, since a synthesized image can be created if there is a difference in drive position between the video signals obtained from the respective optical images. [Other Examples] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-mentioned embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0040] The disclosure of this embodiment includes the following configurations and methods. (Configuration 1) a first optical system and a second optical system arranged in parallel; a first focus lens provided in the first optical system and movable in an optical axis direction; a second focus lens provided in the second optical system and movable in the optical axis direction; a control means for controlling the driving of the first and second focus lenses; The optical device according to claim 1, wherein the control means controls the driving of the first and second focus lenses so that the driven positions of the first and second focus lenses are respectively a focused position and a position that is a predetermined distance away from the focused position. (Configuration 2) 2. The optical device according to claim 1, wherein the predetermined amount is changeable during shooting. (Configuration 3) The lens device described in configuration 1 or 2, wherein the control means determines the driving amount of the first and second focus lenses based on an image focused by one of the first and second optical systems. (Configuration 4) 4. The optical device according to any one of configurations 1 to 3, wherein the control means receives information relating to the predetermined amount and controls the driving in accordance with the information. (Configuration 5) 5. The optical device according to any one of configurations 1 to 4, wherein the optical device is a lens device that is detachably attached to an imaging device. (Configuration 6) the optical device is an imaging device having an imaging element for capturing an image and an image processing means; The optical device described in any one of configurations 1 to 4, characterized in that the image processing means creates a composite image by combining a first image generated by imaging through the first optical system when the first focus lens is located at the in-focus position and a second image generated by imaging through the second optical system when the second focus lens is located at a position away from the in-focus position by the predetermined amount. (Configuration 7) 7. The optical device according to configuration 6, wherein the image processing means creates the composite image during or after shooting. (Configuration 8) 8. The optical device according to configuration 6 or 7, wherein the first image and the second image are combined to obtain a soft focus effect. (Method 1) A method for controlling an optical device having a first optical system and a second optical system arranged in parallel, a first focus lens provided in the first optical system and movable in an optical axis direction, and a second focus lens provided in the second optical system and movable in the optical axis direction, comprising: controlling the driving of the first and second focus lenses; A control method comprising the steps of: controlling the driving of the first and second focus lenses so that their drive positions are respectively a focus position and a position spaced a predetermined distance from the focus position. (Configuration 9) A program for causing a computer to execute a process according to the control method described in Method 1.

[0041] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0042] 100 Lens device (optical equipment) 120a First optical system 120b Second optical system 105a Focus lens (first focus lens) 105b Focus lens (second focus lens) 112 Lens control CPU (control means)

Claims

1. a first optical system and a second optical system arranged in parallel; a first focus lens provided in the first optical system and movable in an optical axis direction; a second focus lens provided in the second optical system and movable in the optical axis direction; a control unit for controlling the driving of the first and second focus lenses; The optical device according to claim 1, wherein the control means controls the driving of the first and second focus lenses so that the driven positions of the first and second focus lenses are respectively an in-focus position and a position spaced a predetermined distance from the in-focus position.

2. 2. The optical device according to claim 1, wherein the predetermined amount is changeable during shooting.

3. 3. The lens apparatus according to claim 1, wherein the control means determines the driving amounts of the first and second focus lenses on the basis of an image focused by one of the first and second optical systems.

4. 3. The optical device according to claim 1, wherein the control means receives information relating to the predetermined amount, and controls the driving in accordance with the information.

5. 3. The optical device according to claim 1, wherein the optical device is a lens device that is detachably mounted to an image pickup device.

6. the optical device is an imaging device having an imaging element for capturing an image and an image processing means; The optical device according to claim 1 or 2, characterized in that the image processing means creates a composite image by combining a first image generated by imaging through the first optical system when the first focus lens is located at the in-focus position and a second image generated by imaging through the second optical system when the second focus lens is located at a position away from the in-focus position by the specified amount.

7. 7. The optical device according to claim 6, wherein the image processing means creates the composite image during or after shooting.

8. 7. The optical device according to claim 6, wherein a soft focus effect is obtained by synthesizing the first image and the second image.

9. A method for controlling an optical device having a first optical system and a second optical system arranged in parallel, a first focus lens provided in the first optical system and movable in an optical axis direction, and a second focus lens provided in the second optical system and movable in the optical axis direction, comprising: A method for controlling the driving of the first and second focus lenses, a control method comprising: controlling the driving of the first and second focus lenses so that the driving positions of the first and second focus lenses are respectively a focus position and a position spaced a predetermined distance from the focus position;

10. A program for causing a computer to execute a process according to the control method according to claim 9.

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