WO2006061938A1 - オートフォーカスシステム - Google Patents
オートフォーカスシステム Download PDFInfo
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- WO2006061938A1 WO2006061938A1 PCT/JP2005/017602 JP2005017602W WO2006061938A1 WO 2006061938 A1 WO2006061938 A1 WO 2006061938A1 JP 2005017602 W JP2005017602 W JP 2005017602W WO 2006061938 A1 WO2006061938 A1 WO 2006061938A1
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- Prior art keywords
- speed
- focus
- lens
- moving speed
- focus lens
- Prior art date
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Classifications
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B17/00—Details of cameras or camera bodies; Accessories therefor
- G03B17/02—Bodies
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/28—Systems for automatic generation of focusing signals
- G02B7/282—Autofocusing of zoom lenses
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
- G02B7/28—Systems for automatic generation of focusing signals
- G02B7/36—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals
- G02B7/365—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals by analysis of the spatial frequency components of the image
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B13/00—Viewfinders; Focusing aids for cameras; Means for focusing for cameras; Autofocus systems for cameras
- G03B13/32—Means for focusing
- G03B13/34—Power focusing
- G03B13/36—Autofocus systems
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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
- H04N23/67—Focus control based on electronic image sensor signals
- H04N23/673—Focus control based on electronic image sensor signals based on contrast or high frequency components of image signals, e.g. hill climbing method
Definitions
- the present invention relates to an autofocus system, and more particularly to an autofocus system that automatically performs focus adjustment based on the contrast of a subject image.
- a contrast method is generally used as an autofocus (hereinafter referred to as AF) method adopted in a television camera or a video camera.
- contrast AF for example, a high frequency component signal is extracted by a filter (electric filter) from a video signal obtained by photographing a subject, and the contrast of the subject image is determined based on the high frequency component signal. High and low (sharpness) is evaluated. Thereby, the focus (focus lens) position of the photographing lens is controlled so that the evaluation value (the focus evaluation value t in this specification) is maximized or maximized (peak point).
- the graph shows the relationship between the focus position on the horizontal axis and the focus evaluation value on the vertical axis (focus evaluation value graph).
- the focus evaluation value curve shows a mountain-shaped distribution in which the focus evaluation value peaks at the focus position. Therefore, as a method of setting the focus at its peak point, the so-called hill-climbing method that detects the direction in which the focus evaluation value increases, moves the focus in that direction, and stops the focus at a position where no increase in the focus evaluation value is detected. It has been known.
- Patent Documents 1 and 2 describe contrast AF.
- the steepness of the peak distribution of the focus evaluation value curve changes depending on the condition of the subject and the optical setting state of the photographing lens. For example, in the case of a high-contrast subject that contains many high-contrast patterns or contour lines, the peak distribution of the focus evaluation value curve becomes steep, and conversely, in the case of a low-contrast subject that has few patterns, borders, etc. Focus evaluation The peak distribution of the value curve becomes gentle.
- a rear focus type photographing lens has a front focus type depending on an aperture value.
- the steepness of the peak distribution of the focus evaluation value curve varies depending on the focal length and aperture value. For example, with the latter photographic lens, the zoom power S becomes closer to the telephoto side (the longer the focal length is), and the closer the aperture is to the open side (the smaller the aperture value), the larger the peak of the focus evaluation value curve. As the distribution becomes steeper and the zoom is widened, and the aperture is reduced (the aperture value is increased), the peak distribution of the focus evaluation value curve becomes gentle.
- Patent Document 1 Japanese Patent Laid-Open No. 63-74273
- Patent Document 2 Japanese Patent Laid-Open No. 03-297282
- the mountain-shaped distribution of the focus evaluation value curve is steep, and hunting occurs at a certain AF speed.
- the peak distribution of the focus evaluation value curve is gently adjusted by adjusting the cutoff frequency of the filter as described above. If hunting is prevented, the AF speed will not slow down (contributes to the high speed of the AF speed), but the AF accuracy will deteriorate. On the other hand, when hunting is prevented by slowing down the AF speed, the AF accuracy does not decrease (contributes to improving AF accuracy), but the AF speed is slowed down. In other words, there is a contradictory relationship between higher AF accuracy and higher AF speed.
- the actual focus evaluation value curve is not determined only by the setting state of the photographing lens, but varies depending on the condition of the subject as described above. For example, in general, the longer the focal length of the taking lens, the steeper distribution of the focus evaluation value curve becomes steeper, but when the subject itself has a low contrast, the focal length is short and long. There is not much change in the steepness of the mountain-shaped distribution of the evaluation value curve. In addition, the degree of steepness of the mountain distribution varies depending on the contrast of the subject itself.
- the filter cutoff frequency and AF speed so that the AF accuracy and AF speed are appropriate for the purpose of AF use, etc.
- the AF accuracy may be too low than intended, or the AF speed can be set to a higher speed without problems such as hunting.
- the AF speed was too high for the steepness of the peak distribution of the focus evaluation value curve, resulting in problems such as hunting.
- the present invention has been made in view of such circumstances, and the setting of a photographing lens for individual photographing is performed.
- the objective is to provide an autofocus system that can perform optimum AF in consideration of the steady state, subject conditions, AF usage purpose, and the like.
- the autofocus system has the ability to move the focus lens of the photographic lens based on the contrast of the subject image formed by the photographic lens.
- the auto focus control means for automatically setting the focus lens to the in-focus position, and the speed instruction means for instructing and inputting the moving speed of the focus lens, the auto focus control means being instructed by the speed instruction means.
- the auto-focus system that moves the focus lens at a high moving speed is also provided.
- the moving speed (AF speed) of the focus lens during AF can be adjusted to match the setting state of the photographic lens, the conditions of the subject, etc. It is possible to reliably prevent problems such as these.
- the autofocus system provides a focus evaluation for calculating a focus evaluation value indicating a contrast of the subject image from a video signal of the subject image formed by the photographing lens in the first aspect.
- a focus evaluation value calculating means having a filter means for extracting a signal in a predetermined frequency band from the video signal;
- Frequency instruction means for instructing and inputting a cutoff frequency of the filter means for cutting off a signal of a frequency component on the high frequency side or low frequency side of the video signal
- the filter means changes the filter characteristics so that the cutoff frequency instructed by the frequency instruction means is obtained.
- the steepness of the peak distribution of the focus evaluation curve can be adjusted by changing the cutoff frequency of the filter means, and the AF accuracy can be adjusted.
- the autofocus system according to a third aspect of the present invention is the autofocus system according to the first aspect, wherein the autofocus control means includes at least a focal length or an aperture value.
- An auto setting mode that automatically sets the AF speed which can perform AF properly under standard subject conditions, is particularly useful when manual adjustment is not required.
- the speed instruction means inputs and inputs a change amount for the moving speed of the focus lens set in the automatic setting mode
- the autofocus control means uses the value obtained by adding the change amount to the moving speed set in the automatic setting mode as the moving speed of the focus lens. If the AF speed can be changed manually based on the AF speed set in the automatic setting mode, the AF speed can be adjusted easily.
- the speed instruction means is configured such that the movement speed of the focus lens is a predetermined speed of movement relative to a standard movement speed It is a means to instruct
- the moving speed of the focus lens that is, the AF speed can be instantaneously switched between high speed and low speed.
- the autofocus system according to the sixth aspect of the present invention is characterized in that, in the fifth aspect, the autofocus system further comprises changing means for changing a standard moving speed of the force lens.
- the autofocus system when the AF speed can be converted into a movement speed that is a predetermined multiple of the standard movement speed force, the standard movement speed itself can be changed to a desired speed.
- An autofocus system is the switch according to the fifth aspect or the sixth aspect, wherein the speed instruction means is disposed in a focus operation device for performing an operation related to the focus lens. It is characterized by that. If the speed instruction means on the fifth side or the sixth side is arranged on a focus operating device such as a focus demand (focus controller), the operability is good.
- AF can be executed under optimum conditions according to the setting state of the taking lens, the condition of the subject, the purpose of use of AF, and the like in each shooting. It becomes like this.
- FIG. 1 is a block diagram showing a configuration of a lens system to which the present invention is applied.
- FIG. 2A is a diagram showing a filter characteristic of a high-pass filter in the focus evaluation value detection unit.
- FIG. 2B is a diagram showing the filter characteristics of the low-pass filter in the focus evaluation value detection unit.
- FIG. 2C is a diagram showing filter characteristics of both filters in the focus evaluation value detection unit.
- FIG. 3 is a front view showing an external configuration of an AF operation unit.
- FIG. 4 shows the filter characteristics of both HPF and LPF filters, and shows how the cutoff frequency is changed in the filter manual setting mode.
- FIG. 5A is a diagram showing a general effect on the focus evaluation value curve when the cutoff frequency of HPF is increased.
- FIG. 5B is a diagram showing a general effect on the focus evaluation value curve when the cutoff frequency of HPF is lowered.
- FIG. 6A is an explanatory diagram used for explaining the setting of the AF speed.
- FIG. 6B is an explanatory diagram used for explaining the setting of the AF speed.
- FIG. 7 is a flowchart showing the procedure for setting the cutoff frequency of AF speed, HPF, and LPF.
- FIG. 8 is a block diagram illustrating a configuration of a lens system to which an autofocus system according to another embodiment is applied.
- FIG. 9 is an external view showing an example of the arrangement of AF speed adjustment knobs on the EFP lens.
- FIG. 10 is an external view showing an example of the arrangement of AF speed adjustment knobs on the ENG lens.
- FIG. 11 is an external view showing an external appearance of a focus demand in which an AF speed switching switch is arranged.
- FIG. 12 is a flowchart showing an AF speed setting procedure in another embodiment.
- FIG. 1 is a block diagram showing a configuration of a lens system to which the present invention is applied.
- the lens system shown in the figure is, for example, a lens system used in a television camera for television broadcasting, and is composed of a photographic lens (optical system) and a control system that omits a detailed configuration.
- the taking lens of the lens system is mounted on a camera body (not shown) with interchangeable lenses by a mount, and a subject image is formed on the light receiving surface of an image sensor provided in the camera body by the taking lens.
- the photographic lens is equipped with optical components such as the zoom lens (group) ZL, focus lens (group) FL, and aperture I shown in the figure.
- the zoom lens ZL and force lens FL are movable in the optical axis direction. Arranged and connected to motors ZM and FM respectively. Therefore, the zoom lens ZL and focus lens FL move in the direction of the optical axis by the driving force of the motors ZM and FM, and the zoom magnification (focal length) of the imaging lens changes as the zoom lens ZL moves.
- the focus position of the taking lens changes as the focus lens FL moves.
- the diaphragm I is connected to the motor IM, and the brightness of the image is changed by opening and closing by the driving force of the motor IM.
- the control system of the lens system includes a CPU 10, an AZD converter 12, a DZA converter 14, a focus evaluation value detection unit 18, an amplifier ZA, FA, IA, and a position, which are mounted on the lens device integrated with the above-described photographing lens.
- Sensor ZP, FP, IP control unit, zoom demand 30, focus demand 32, AF operation unit (AF operation unit) 34, etc. connected to the lens unit with cables.
- the zoom (Zoom lens ZL) and focus lens (FL) of the scene lens can be operated manually using a controller connected to the lens unit, such as Zoom Demand 30 and Focus Demand 32.
- a zoom command signal indicating the target position of the zoom (zoom lens ZL) or the moving speed is sent from the zoom demand 12 via the AZD converter 12 according to the operation.
- CP U10 Given to CP U10.
- the CPU 10 controls the rotational speed of the motor ZM by the value of the zoom control signal output to the amplifier ZA via the DZA converter 14, and controls the zoom lens ZL connected to the motor ZM by the zoom command signal. Control is performed so that the commanded target value is obtained.
- the CPU 10 acquires information on the current position of the zoom lens ZL necessary for zoom control from the position sensor ZP via the AZD conversion 12.
- the CPU 10 controls the rotation speed of the motor FM according to the value of the focus control signal output to the amplifier FA via the DZA variable ⁇ 14 as in the zoom control, and the focus lens FL connected to the motor FM. Is controlled so that it becomes the target value commanded by the focus command signal. Note that the CPU 10 acquires information on the current position of the focus lens FL necessary for focus control from the position sensor FP via the AZD converter 12.
- the aperture I of the photographic lens is controlled by an iris command signal of the camera body force, not shown, for example, where the photographic lens is attached.
- the target value of the aperture position that makes the image brightness appropriate based on the video signal obtained by the above is given to the CPU 10 as an iris command signal from the camera body via the AZD change.
- the CPU 10 controls the rotational speed of the motor IM based on the value of the iris control signal output to the amplifier IA via the DZA converter 14, and sets the aperture I connected to the motor IM to the target value based on the iris command signal. To control the aperture position commanded as Note that the CPU 10 acquires information on the current position of the diaphragm I necessary for diaphragm control from the position sensor IP via the AZD converter 12.
- an autofocus system has been constructed in this lens system, and the above-described manual focus (MF) mode is achieved by the AF switch S1 disposed in the lens device housing, the controller connected to the lens device, or the like.
- the AF control that automatically adjusts the focus of the taking lens is executed by the CPU10 and so on.
- this system employs contrast-based AF that detects the contrast of the subject image and performs focus control to maximize the contrast, thereby setting the focus to the in-focus state.
- the CPU 10 controls the motor FM based on a focus command signal given in accordance with a manual operation at the focus demand 32 or the like, and is in a state (position or position) commanded by the focus command signal.
- the focus lens FL is controlled so that the movement speed is reached.
- the CPU 10 detects the operation and shifts to the AF mode, and executes the following AF control.
- a subject image formed by the photographing lens is photoelectrically converted by an image sensor and processed by various processing circuits to generate a video signal in a predetermined format (for example, NTSC format in this embodiment).
- the video signal (luminance signal) is supplied to the focus evaluation value detection unit 18 of the lens apparatus as well as the camera body. Focus evaluation during AF control
- the value detecting unit 18 detects the contrast level of the subject image as a focus evaluation value based on the video signal given from the camera body, and gives the focus evaluation value to the CPU 10.
- the focus evaluation value detection unit 18 is also configured with an AZD change 20, a high-pass filter (HPF) 22, a single pass filter (LPF) 24, a gate circuit 26, an adder circuit 28, and the like.
- the video signal input to the focus evaluation value detector 18 is first converted from an analog signal to a digital signal by the AZD converter 20.
- the video signal converted into a digital signal is input to the HPF22, and a predetermined cutoff frequency f f is obtained by the HPF22 having the filter characteristics as shown in Fig. 2 ⁇ .
- Signals with frequency components lower than CL are cut off, and signals with frequency components higher than the cutoff frequency CL are extracted.
- the video signal extracted by the HPF 22 is input to the LPF 24 as shown in FIG. 2B, and the LPF 24 blocks a signal having a frequency component higher than a predetermined cutoff frequency f.
- a signal having a frequency component lower than that of CH is extracted.
- the HPF22 and LPF24 are digital filters whose filter characteristics can be changed by a filter coefficient given by an electric signal, for example, and the HPF22 cutoff frequency f or The filter characteristics such as cutoff frequency f of LPF24 are changed.
- the HPF 22 and the LPF 24 may be configured by one band pass filter.
- the video signal in the subject range (for example, the rectangular range in the center of the screen and called the AF area) is extracted.
- the video signal in the AF area thus extracted is input to the adder circuit 28 and integrated for each field.
- the integrated value obtained for each field by the adder circuit 28 in this manner indicates the level of contrast of the subject image in each field, and the integrated value is used as a focus evaluation value for the CP.
- the CPU 10 acquires the focus evaluation value calculated by the focus evaluation value detection unit 18 as described above, and amplifies the focus control signal as in the MF mode. Output to FA to control the rotation speed of motor FM. As a result, the focus lens FL is moved to a position where the focus evaluation value is maximized (maximum).
- a known hill-climbing method is applied as a control method for moving the focus lens FL to a position where the focus evaluation value is maximized (maximum).
- the CPU 10 causes the focus lens FL to be displaced by a small amount (so-called ⁇ bring) back and forth (so-called infinite distance) with the position set at that time as the reference position, and the reference position and each displacement.
- the focus evaluation value at the point is acquired from the focus evaluation value detection unit 18.
- the direction in which the focus evaluation value increases with respect to the reference position is detected. If the increasing direction is not detected, the focus lens FL is set in the initial stage, and the AF control is terminated while the focus lens FL is stopped at the reference position with the reference position as the focus position.
- the focus lens FL is moved in that direction at a predetermined speed. Then, the focus evaluation value is acquired from the focus evaluation value detection unit 18 while moving the focus lens FL or appropriately stopped, and the newly acquired focus evaluation value is increased from the previously acquired focus evaluation value. Judge whether it is power.
- the moving speed of the focus lens FL at this time is called the AF speed.
- the AF speed is not constant because it changes during acceleration or deceleration, but it is expressed by a characteristic speed value, such as the maximum speed value or the average speed value.
- the focus lens FL is continuously moved in the same direction.
- the focus evaluation value peak point that is, the in-focus position has passed
- the moving direction of the focus lens FL is reversed and moved at a low speed.
- an AF operation unit 34 is connected to the lens device, and the user operates the AF operation unit 34 to set the AF speed and the cutoff frequencies f and f of the HPF 22 and LPF 24 to desired values. It has become possible to adjust to.
- Figure 3 shows the AF operation.
- FIG. 3 is a front view showing the appearance of cropping part 34.
- the AZM switch 50 has an automatic filter setting that automatically sets the cutoff frequencies f and f of the HPF22 and LPF24,
- This switch selects one of the manual filter setting modes. In the off state, the filter automatic setting mode is selected and the built-in lamp is turned off. In the on state, the filter manual setting mode is selected and the built-in lamp is lit.
- the CPU 10 communicates with the AF operation unit 34 and acquires the on / off state of the AZM switch 50, thereby detecting which mode is selected between automatic filter setting and manual filter setting.
- the CPU 10 sets the filter coefficient given to the HPF 22 and LPF 24 to a value that takes into account the focal length of the shooting lens (position of the zoom lens ZL) and the aperture value (position of the iris I).
- Figure 2 shows the cutoff frequency of HPF22 (cutoff frequency on the low side) f and the cutoff frequency of LPF24 (cutoff frequency on the high side).
- the CPU 10 changes the filter coefficient applied to the HPF 22 and LPF 24 according to the manual operation of the AF operation unit 34, HPF22 cutoff frequency (low frequency cutoff frequency) f and LPF24 cutoff frequency (high frequency cutoff frequency) f are specified manually.
- dials 52 and 54 specify the cutoff frequency f of HPF22 and the cutoff frequency f of LPF24 in the filter manual setting mode, respectively.
- the rotational positions of the dials 52 and 54 are detected by the potentiometer and given to the CPU 10. [0052]
- the CPU 10 gives the filter coefficient corresponding to the rotational position of the dial 52 to the HPF 22 to set the cutoff frequency f of the HPF 22 to a value (manual setting) according to the rotational position of the dial 52.
- the cut-off frequency f of the LPF 24 is a value corresponding to the rotational position of the dial 54 (
- the cut-off frequencies of HPF 22 and LPF 24 are changed as follows.
- Figure 4 shows the filter characteristics of both HPF22 and LPF24 filters.
- the cut-off frequency f of the low frequency side which is the cut-off frequency of HPF22, is 52
- the low-frequency cutoff frequency f is the value of f.
- the high frequency side cut-off frequency f which is 24 cut-off frequency
- LO CH0 is a force filter automatic setting mode that is set to a predetermined constant value in this embodiment.
- cutoff frequency (standard value) of HPF22 and LPF24 may be changed according to the setting state of the taking lens.
- the cut-off frequency of HPF22 and LPF24 can be changed in the filter manual setting mode, so that the sharpness of the peak distribution of the focus evaluation value curve is set in the shooting lens for individual shooting. It is possible to set an optimal state in consideration of the subject condition, the purpose of AF use, etc.
- 5A and 5B are focus evaluation value graphs showing the position of the focus lens FL on the horizontal axis and the focus evaluation value on the vertical axis.
- the focus lens FL is applied to a certain subject.
- the change in the focus evaluation value when the close-end force is moved to the infinite end is expressed as the cutoff frequency f of the HPF22.
- the photographing lens of the present embodiment is a front focus type
- the mountain distribution of the focus evaluation value curve becomes steep. If the peak distribution of the focus evaluation value curve is very steep, the focus lens FL will not stop at the peak point of the focus evaluation value and will not stop near the peak point unless the AF speed is set sufficiently low. However, if the AF speed is set too low, the time required for focusing increases.
- the peak distribution of the focus evaluation value curve can be made moderately steep by automatically lowering CL, hunting can be prevented without making the AF speed too low, and the user's effort is reduced. It is effective because there is not.
- the focal length and aperture value of the photographic lens are taken into account in this way, and generally the cutoff frequency of HPF22 and LPF24 (standard) so that the peak distribution of the focus evaluation value curve is moderately steep. Value) is set.
- the steepness of the peak distribution of the focus evaluation value curve and the effect of changing the cutoff frequency of HPF22 and LPF24 are not limited to the shooting lens settings such as focal length and aperture value. Therefore, if the cutoff frequency of the HPF22 or LPF24 is automatically set considering only the setting condition of the photographic lens, hunting may occur depending on the subject conditions, or the AF accuracy may be too poor. There is.
- the user manually adjusts the cutoff frequency of HPF22 or LPF24 to adapt to the shooting lens setting status, subject conditions, etc. in individual shooting, to reliably prevent hunting,
- the filter manual setting mode that can prevent the AF accuracy from becoming too bad is very effective.
- the cutoff frequency of the HPF 22 or LPF 24 in the filter automatic setting mode may be constant regardless of the setting state of the photographing lens.
- the filter characteristics other than the cut-off frequency can be changed intentionally by changing the filter coefficients of HPF22 and LPF24, the main purpose of this embodiment is to change the cut-off frequency. Let's not mention the filter characteristics!
- the AZM switch 56 is a switch for selecting a mode between automatic AF speed setting for automatically setting the AF speed and manual AF speed setting for manual setting. When it is off, the AF speed automatic setting mode is selected and the built-in lamp goes off.When it is on, the AF speed manual setting mode is selected and the built-in lamp lights. .
- the CPU 10 communicates with the AF operation unit 34, acquires the on / off state of the AZM switch 56, and determines whether the AF speed automatic setting mode or the AF speed manual setting mode is selected. To detect. When the AF speed automatic setting mode is selected, the CPU 10 automatically sets the AF speed. When the AF speed is set automatically, the focal length and aperture value are taken into account, and during AF control, the CPU 10 determines the position of the zoom lens ZL and the position of the aperture I from the position sensor ZP and position sensor IP shown in Fig. 1. , And based on those positions, set the AF speed to the standard value (standard value).
- FIGS. 6A and 6B show a mountain-shaped distribution of general focus evaluation curves when the focal length is long and short, respectively, and the longer the focal length, the focus evaluation value curve.
- the peak distribution becomes steep and the focal length is shorter, the peak distribution of the focus evaluation value curve becomes gentler.
- the AF speed in the AF speed automatic setting mode is indicated by the arrow a in FIG. 6A and the arrow b in FIG. 6B.
- the longer the focal length (and the smaller the aperture value) the lower the speed, and the shorter the focal length (and the larger the aperture value!), The higher the speed.
- the CPU 10 sets the AF speed to a value designated by the manual operation.
- the dial 58 is in the AF speed manual setting mode.
- the rotational position of the dial 58 is detected by the potentiometer and given to the CPU 10.
- the CPU 10 sets the value corresponding to the rotational position of the dial 56 as a manual setting value, and sets the manual setting value to the AF speed (standard value) determined by the position of the zoom lens ZL and aperture I in the AF speed automatic setting mode. Set the added value as the AF speed in focus manual setting mode.
- the manual setting value is 0, and the AF speed at this time is set to the standard value that is automatically set in the AF speed automatic setting mode.
- This standard value varies depending on the focal length and aperture value during AF control, as indicated by arrows a and b in FIGS. 6A and 6B.
- dial 56 is turned clockwise from the middle position, the manually set value increases from 0 to the positive direction (H direction in Fig. 6A and Fig. 6B), and this value is added to the standard value to increase the AF speed. The direction is changed.
- dial 56 When dial 56 is also turned counterclockwise, the manually set value increases (decreases) from 0 in the negative direction (L direction in Figs. 6A and 6B), and that value is added to the standard value and AF The speed is changed in the direction of slowing down.
- the AF speed automatic setting mode can prevent hunting for standard subject conditions, and can be troublesome for the user. It is effective in that there is no.
- the sharpness of the peak distribution of the focus evaluation value curve is not determined only by the setting state power of the photographic lens, but also varies depending on the conditions of the subject, and hunting may occur. , AF speed may become unnecessarily slow.
- the AF speed manual setting mode which can set the AF speed to suit the shooting lens settings and subject conditions in individual shooting, can reliably prevent hunting and AF This is very effective because it can avoid the problem that the speed is unnecessarily slow.
- the filter manual setting mode and the AF speed manual setting mode, it is possible to achieve AF accuracy and AF speed suitable for the intended use of AF under the restriction that hunting does not occur.
- the AF accuracy can be prioritized over the AF speed.
- high-precision focusing is required. In such a case, AF aimed at focusing with high AF accuracy is desired.
- the AF speed has priority over the AF accuracy.
- adjust the AF speed manually to a speed that meets your requirements, and adjust the cut-off frequency of the HPF22 or LPF24 so that problems such as hunting do not occur at that AF speed.
- Suitable AF can be performed. Note that the AF speed and HPF22 and LPF24 cutoff frequency setting methods described here are only examples and are not limited to this.
- the AF operation unit 34 stores a rotational position of the dials 52, 54, and 58, and is equipped with a memo function for outputting the stored rotational position to the CPU 10 of the lens device.
- the AF operation unit shown in FIG. 3 is provided with a memo switch 60 and selection switches 62 from 1 to 4!
- the desired selection switch 62 is pressed while the memo switch 60 is turned on and the built-in lamp is lit
- the rotation position data of the dials 52, 54, and 58 set at that time is stored in the built-in memory. Retained. If the deviation between the AF speed and the force-off frequency is in the automatic setting mode, the automatic setting mode will also store the data on the dial rotation position. It is possible to store data indicating that the mode is automatic setting mode (A / M switch 50 or AZM switch 5 6 is off (automatic setting)) instead of the dial rotation position! /.
- AF speed and the cutoff frequency of HPF22 and LPF24 may be stored in this way so that the high-speed AF mode can be read with a name such as the subject mode.
- the data stored in correspondence with each selection switch 62 is stored in the EEPROM 16 (see FIG. 1) that can be directly referenced by the CPU 10 but not in the AF operation unit 34, and the memo switch 60 or the like obtained from the AF operation unit 34 is stored.
- CPU10 may store and read data such as AF speed.
- the CPU 10 performs necessary initial settings (step S 10) and then executes processing other than AF control (step S 12). Subsequently, whether or not the AF mode is selected depends on whether or not the AF switch S1 is turned on. (Step S14).
- the AF in this embodiment is a one-shot AF, but the so-called continuous AF, in which AF control is continuously performed even after the user enters the in-focus state, unless the user intentionally switches to the MF mode.
- the AF speed and cut-off frequency can be set manually, for example, when the AF switch S1 is turned on once, the AF mode will continue without switching to the MF mode until it is turned on again. While doing this, repeat the AF mode process similar to One Shot AF explained below!
- step S14 If CPU 10 determines NO in step S 14, it returns to the process in step S 12. On the other hand, if YES is determined in step S14, the process proceeds to AF mode processing. First, the aperture I position (aperture position) IP and the zoom lens ZL position (zoom position) ZP are read (step S16). , S18).
- step S20 the setting in the AF operation unit 34 is read (step S20), and it is determined whether or not the filter manual setting mode is set (step S22).
- step S24 If NO, that is, if the filter automatic setting mode is determined, the filter coefficients of HPF22 and LPF24 corresponding to the aperture position IP and the zoom position ZP are obtained and set to HPF22 and LPF24 (step S24). . On the other hand, if it is judged as YES In this case, the manually set value of the cutoff frequency of HPF22 and LPF24 specified by the rotation positions of the dials 52 and 54 of the AF operation unit 34 is read, and the corresponding filter coefficients are set in HPF22 and LPF24 (step S26). ).
- step S24 the CPU 10 next obtains a standard value FS of AF speed corresponding to the aperture position IP and the zoom position ZP (step S28). Subsequently, it is determined whether or not the AF speed manual setting mode is set based on the setting of the AF operation unit 34 (step S30).
- the AF speed standard value FS obtained in step S28 is set to the AF speed, and the focus evaluation value is read from the focus evaluation value detection unit 18.
- the AF control is executed so that the focus evaluation value reaches a peak by moving the focus lens FL at the AF speed (step S34).
- step S30 that is, if it is determined that the AF speed manual setting mode is selected, the manual setting value corresponding to the rotational position of the dial 58 of the AF operation unit 34 is read, and the value is read in step S28.
- the AF control is executed so that the focus evaluation value reaches a peak by moving the focus lens FL at the AF speed set in step S32 from S. S34).
- step S 12 the processing from step S 12 is executed.
- the cutoff frequency of the filter and the AF speed can be manually set by the AF operation unit 34.
- the AF operation unit 34 is not limited to being connected to the lens device with a cable, and may be disposed integrally with the lens device or the focus operation unit! /.
- FIG. 8 is a block diagram showing a configuration of a lens system to which the autofocus system of the present embodiment is applied.
- the same or similar constituent blocks as those of the lens system shown in FIG. The description is omitted.
- the AF operation unit 34 of FIG. 1 is not connected to the lens device, and an AF speed adjustment knob 80 is provided!
- the lens apparatus shown in FIG. 9 is an EFP lens mainly used in a studio as shown in FIG. 9, the periphery thereof is covered with a box-shaped cover 90, and the AF speed adjustment knob 80 is, for example,
- the cover 90 is rotatably provided on the side surface.
- the lens unit is an ENG lens that is mainly used for coverage as shown in Fig. 10
- the position of each of the focus lens FL, zoom lens ZL, and aperture I is operated on the lens barrel 100 of the taking lens.
- Rotating operation rings 102, 104, and 106 are provided for driving the lens barrel 100, and a drive unit 108 for driving the operation rings 102 to 106 is provided on the side of the lens barrel 100.
- the AF speed adjustment knob 80 is rotatably provided on the back surface of the drive unit 108, for example.
- the CPU 10 performs the automatic filter setting process and the automatic AF speed process described in the above embodiment during the AF control, and the focal length of the photographing lens (zoom lens). Based on the ZL position) and aperture value (aperture I position), the HPF22 and LPF24 force cutoff frequency f, f and AF speed are set automatically.
- the AF speed is set to a standard value (standard value) according to the focal length and aperture value, and is set to a different value depending on the focal length and aperture value.
- the standard value corresponding to the aperture value can be increased or decreased as a whole by the AF speed adjustment knob 80.
- the focus demand 32 is provided with an AF speed switching switch.
- the focus demand 32 is configured as shown in FIG. 11, and a focus knob 122 for manually operating the focus lens FL during MF control is provided on a cylindrical main body 120 having various circuits built therein. It is provided so that rotation is possible.
- an AF speed switching switch 82, an AF switch 124 (AF switch S1 in FIG. 8), a joystick 126, and the like are provided on the peripheral surface of the main body 120.
- the AF switch S1 is a switch for shifting to the MF mode force AF mode and executing AF control as described in the above embodiment, and the joystick 126 images the position of the AF area that is the target range of AF. In range It is an operation member for moving up, down, left and right.
- the AF speed switching switch 82 is a slide switch that can be switched between the standard mode and the high-speed mode.
- the AF speed is adjusted as described above. It is set to the standard value set with knob 80.
- the AF speed switching switch 82 is set to the high speed mode on the right side in the figure, the AF speed can be switched to a speed obtained by multiplying the standard value in the standard mode by a predetermined magnification. ing. For example, a magnification between 2 and 4 times is preferable as the magnification. As a result, if you want to make the AF speed faster than the standard speed, you can instantly speed up the AF speed! /
- FIG. 12 is a flowchart showing the AF speed setting procedure in the CPU 10 of the present embodiment.
- the CPU 10 first performs the required initial settings (step S50), then executes processing other than AF control (step S52), and then whether or not the AF switch 124 (S1) of the focus demand 32 is turned on. It is determined whether or not the AF mode is selected (step S54). If NO is determined, the process returns to step S52.
- the process proceeds to the AF mode processing, first, the position (aperture position) IP of the diaphragm I, the position of the zoom lens ZL (zoom position) read ZP (step S56, S58) 0 Subsequently, the setting value VR of the AF speed adjustment knob 80 is read (step S60). In addition, the setting of the AF speed switching switch 82 of the focus demand 32 is read (step S62).
- the CPU 10 obtains respective filter coefficients of HPF22 and LPF24 corresponding to the aperture position IP and the zoom position ZP, and sets them in HPF22 and LPF24 (step S64).
- CPU10 calculates the standard value of the AF speed corresponding to the aperture position IP, zoom position ZP, and AF speed adjustment knob 80 setting value VR, and uses that value as the AF speed setting value (movement speed) FS (Step S66). Then, it is determined whether or not the mode set by the AF speed switching switch 82 is the high speed mode (step S68).
- step S72 If NO, that is, if the standard mode is determined, the focus lens FL is moved at the AF speed of the set value FS set in step S66 while reading the focus evaluation value from the focus evaluation value detection unit 18, and the focus is adjusted. The above AF control is executed so that the evaluation value reaches a peak (step S72).
- step S68 that is, if the high-speed mode is determined
- Step S72 the process from step S52 is executed.
- the AF speed adjusting knob 80 is provided at a desired position of a desired device (for example, the focus demand 32) even if it is not a lens device.
- the AF speed switching switch 82 can be provided at a desired position of a desired device (for example, a lens device) even if it is not the focus demand 32.
- the speed in the high-speed mode of AF speed, it was recommended that the speed be 2 to 4 times faster than the AF speed in the standard mode, but it should be converted to other magnifications (can be 1 or less). Alternatively, it may be set and changed to a desired magnification.
- an adjustment knob for speed setting in the standard mode and an adjustment knob for speed setting in the high-speed mode may be provided separately.
- the AF speed switch 82 is not limited to selecting two modes, the standard mode and the high-speed mode, but two or more modes can be selected to switch between different speeds for the standard mode and the standard mode. You may do it.
- AF speed automatic setting mode and the AF speed manual setting mode can be selected as in the embodiment described with reference to FIGS. 1 to 7, the implementation described with reference to FIGS. It is possible to apply the technique of the embodiment, and the standard value of the AF speed in the embodiment described with reference to FIGS. 1 to 7 may be changed by the set value of the AF speed adjustment knob 80.
- AF speed automatic setting mode force Regardless of the AF speed manual setting mode, or in a specific mode, if the AF speed changeover switch 82 is used to switch to the standard mode force high speed mode, the AF speed changes to the AF speed of the standard mode. On the other hand, let's be able to switch to a predetermined multiple. In the embodiment described with reference to FIGS.
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Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP05785814.4A EP1830209B1 (en) | 2004-12-08 | 2005-09-26 | Autofocus system |
US11/792,541 US7880800B2 (en) | 2004-12-08 | 2005-09-26 | Auto focus system that controls focusing speeds and movements based on image conditions |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004-355332 | 2004-12-08 | ||
JP2004355332A JP3982707B2 (ja) | 2004-03-12 | 2004-12-08 | オートフォーカスシステム |
Publications (1)
Publication Number | Publication Date |
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WO2006061938A1 true WO2006061938A1 (ja) | 2006-06-15 |
Family
ID=36577768
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2005/017602 WO2006061938A1 (ja) | 2004-12-08 | 2005-09-26 | オートフォーカスシステム |
Country Status (3)
Country | Link |
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US (1) | US7880800B2 (ja) |
EP (1) | EP1830209B1 (ja) |
WO (1) | WO2006061938A1 (ja) |
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US8405759B2 (en) * | 2007-09-27 | 2013-03-26 | Olympus Imagining Corp. | Imaging device with contrast AF, and control method for imaging device with contrast AF |
US8280194B2 (en) | 2008-04-29 | 2012-10-02 | Sony Corporation | Reduced hardware implementation for a two-picture depth map algorithm |
US8194995B2 (en) * | 2008-09-30 | 2012-06-05 | Sony Corporation | Fast camera auto-focus |
US8553093B2 (en) * | 2008-09-30 | 2013-10-08 | Sony Corporation | Method and apparatus for super-resolution imaging using digital imaging devices |
US8199248B2 (en) * | 2009-01-30 | 2012-06-12 | Sony Corporation | Two-dimensional polynomial model for depth estimation based on two-picture matching |
US8945326B2 (en) | 2010-09-14 | 2015-02-03 | The Procter & Gamble Company | Method of making prefastened refastenable disposable absorbent articles |
CN105190392B (zh) | 2013-02-14 | 2018-02-13 | 富士胶片株式会社 | 摄像装置和对焦控制方法 |
WO2015015877A1 (ja) * | 2013-07-29 | 2015-02-05 | オリンパスメディカルシステムズ株式会社 | 撮像装置 |
JP6363855B2 (ja) * | 2014-03-18 | 2018-07-25 | キヤノン株式会社 | レンズ装置、撮像装置、撮像システムの制御方法、プログラム、記憶媒体 |
JP6446598B2 (ja) | 2016-03-31 | 2018-12-26 | 富士フイルム株式会社 | レンズ装置、撮像装置、レンズ駆動方法、レンズ駆動プログラム |
CN114544004A (zh) * | 2022-02-25 | 2022-05-27 | 浙江天铂云科光电股份有限公司 | 一种用于红外热像仪的自动聚焦方法 |
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Also Published As
Publication number | Publication date |
---|---|
EP1830209B1 (en) | 2013-04-17 |
EP1830209A1 (en) | 2007-09-05 |
US7880800B2 (en) | 2011-02-01 |
EP1830209A4 (en) | 2010-11-10 |
US20080084497A1 (en) | 2008-04-10 |
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