JP2003270522A - Photographing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photographing device which can reduce the time lag generated during driving of a focusing lens by setting the driving from of the focusing lens according to the depth of field in photographing operation. <P>SOLUTION: The photographing device is provided with control means 1 of; previously setting the focusing lens from a reference position of driving to a specific distance by lens driving means by being homologized with a focal length and lens driving direction; determining the depth of field which is the reference by repetitively activating photometric means 2 and ranging means 3 for the specified time when the operation for starting the preparation action for photographing is performed; calculating the depth of field in accordance with the photographing diaphragm stop calculated from the specific distance and the final photometric data, and the focal length when the operation for photographing is carried out during this time; and performing the photographing as it is when the final depth of field in the photographing operation is within the depth of field which is the reference. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing device,
More specifically, it relates to a configuration for eliminating a release time lag at the time of shooting.

[0002]

2. Description of the Related Art A camera, which is a photographing device, performs photometry and distance measurement in the process of pressing a release button, and also drives a lens for focusing based on the photometry and distance measurement data, and then drives a shutter. Some have a structure capable of winding a film. However, if the release button is pressed almost simultaneously without taking into account the steps of lens drive based on photometry and distance measurement, shutter drive, and film winding, the time required for lens drive appears as a time lag. Therefore, a method for eliminating the occurrence of such a time lag has been proposed (for example, Japanese Patent Laid-Open No. 8-76169).

In the above publication, the focus adjusting lens is set to the hyperfocal length by the lens driving means in advance, and the lens is driven when the aperture value obtained by photometry is larger than the predetermined aperture value. If the photographing operation is started without performing the photographing operation, and if the photographing operation is small, the lens is driven based on the distance measurement information calculated by operating the distance measuring means to focus, and the aperture value obtained by the photometry is a predetermined aperture value. A method of focusing an object with the depth of field of a lens set to a hyperfocal length when the value is larger than the value is disclosed.

[0004]

As disclosed in the above publication, the lens driving means is operated only when the aperture value obtained by photometry is smaller than a predetermined aperture value. In this case, the time lag due to lens drive can be reduced, but since the lens is fixed at the hyperfocal position, the time lag when moving the lens for short-distance photography from the hyperfocal position according to the aperture value becomes large. There is a risk.

For close-up photography, there is a case where a flashmatic system is used in which the emitted light amount is kept constant and the aperture value is controlled to adjust the exposure amount on the film surface. Even in this case, since the lens needs to be driven to a position corresponding to the aperture value, the above-mentioned problem of time lag may occur.

When the hyperfocal position is set as the initial position of the lens and the number of close-range shots is large, it is necessary to drive the lens in accordance with the close-up shot conditions each time, which also causes a problem of time lag. become.

It is an object of the present invention to provide a photographing apparatus capable of reducing a time lag until the photographing is started by operating a release switch.

[0008]

The invention according to claim 1 is
In a photographing device equipped with a distance measuring unit, a photometric unit and a lens driving unit for driving a focus adjusting lens, the lens adjusting unit drives the focus adjusting lens in advance in correspondence with a focal length and a lens driving direction. When a predetermined distance position is set from the reference position of No. 2, and the operation for starting the shooting preparation operation is performed, the photometry and distance measuring means are repeatedly operated for a fixed time to obtain the reference depth of field, When an operation for shooting is performed in step 1, the depth of field is calculated based on the specific distance, the shooting aperture value calculated from the final photometric data, and the focal length, and the final shooting distance during the shooting operation is performed. When the depth of field is within the depth of field serving as the above-mentioned reference, a control means for performing shooting as it is is provided.

According to a second aspect of the present invention, there is provided in advance a photographing apparatus equipped with a distance measuring means, a photometric means, a lens driving means for driving a focus adjusting lens, a light emitting means for performing flash photographing, and a charging means thereof. When the operation for starting the photographing preparation operation is performed by setting the focus adjusting lens at a specific distance position from the driving reference position by the lens driving means in correspondence with the focal length and the lens driving direction. , The photometric and distance measuring means are repeatedly operated for a fixed time to obtain a reference depth of field, and when an operation for photographing is performed during that time, the specific distance and the final photometric data are calculated. The depth of field is calculated based on the shooting aperture value and the focal length, and if the final depth of field at the time of shooting operation is outside the reference depth of field, the depth of field is calculated. Performed Yumachikku calculation, in the case of the scene in depth the depth of field to recalculate the depth of field according to the aperture value of flashmatic is standard,
It is characterized in that a means for performing stroboscopic photography by the light emitting means is provided as it is by using the focus adjusting lens at the specific distance set under the condition where the depth of field as the reference is obtained.

The invention according to claim 3 is the invention according to claim 1 or 2.
In addition to the invention described above, the control means, as a focus adjustment method of the focus adjustment lens, when using a focus adjustment method driven from the long distance side to the short distance side, the final depth of field is The focus adjusting lens is determined to be outside the reference depth of field, and the position of the focus adjusting lens (distance to the subject) is closer to a predetermined position than a preset specific position. Drive the lens to the position within the depth without returning it to the driving reference position, and judge that the position of the focus adjustment lens (distance to the subject) is farther than the preset specific position. In this case, the focus adjustment lens is driven from its drive reference position to a position within the depth.

The invention according to claim 4 is the invention according to claim 1 or 2.
In addition to the invention described, the control means, as a focus adjustment method of the focus adjustment lens, when using a focus adjustment method driven from the short distance side to the long distance side, the final depth of field is The focus adjustment lens is determined to be outside the reference depth of field, and the position of the focus adjustment lens (distance to the subject) is farther than the preset specific position. Was driven to a position within the depth without returning to the drive reference position, and it was determined that the position of the focus adjustment lens (distance to the subject) was closer than a specific position set in advance. In some cases, the focus adjusting lens is driven from its drive reference position to a position within the depth.

The invention according to claim 5 is the invention according to claim 3 or 4.
In addition to the invention described, when the control means determines that the position of the focus adjusting lens is closer than the specific position, shifts the specific position to the short distance side to the long distance side. If it is determined that there is such a position, the specific position is shifted to the far side and used for the next determination of the final depth of field.

According to a sixth aspect of the invention, in addition to the fourth aspect of the invention, the control means controls the amount of shift to the long distance side relative to the amount of shift to the short distance side when shifting the specific position. It is characterized by making it smaller.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram for explaining a control means of an image pickup apparatus according to an embodiment of the present invention. The control means shown in the figure includes a control unit 1 whose main part is a microcomputer. The control unit 1 has a distance measuring unit 2 through an I / O interface (not shown).
A photometric unit 3, release switches SW1 and SW2, a shutter unit 4, a film feeding unit 5, a display device 6 using a liquid crystal (LCD), and a focus unit 7 are connected to each other.

The distance measuring unit 2 uses an autofocus IC for obtaining a shooting distance to a subject by calculation processing. The distance-measuring information from the distance-measuring unit 2 is fetched by the control unit 1 to be stored as subject distance information and converted into the number of focus extension pulses for zooming the lens.

The photometric unit 3 uses a photometric IC for calculating the brightness of a subject by arithmetic processing. The photometric information from the photometric unit 3 is captured by the control unit 1 and stored as subject luminance information, and is also converted into shutter speed and aperture value (F value) information.

The release switches SW1 and SW2 are switches used when performing a photographing operation. When the release switch SW1 is turned on, photometry, distance measurement, focus operation, etc. are activated, and the release switch SW2 is activated from that state. By turning on, the shutter is opened and closed, the film is fed, and the like, so that the photographing operation can be completed.

The shutter unit 4, the film feeding unit 5 and the display device 6 are units for controlling opening / closing of the shutter, feeding control such as film winding, and displaying various information.

The focus unit 7 is a device for driving a focus lens which is a focus adjustment lens. The focus lens has a reference position on the infinite side, and when the subject is on the short distance side. , Focusing is performed by increasing the payout weight, and it has the function of focusing. The amount of extension for focusing is calculated by the control unit 1 based on subject distance information obtained by the distance measuring unit 2, that is, distance measuring data, focal length, aperture value (F value) information, and the like, and the result is calculated. Is output to the focus unit 7 as the output pulse number. For this reason, the farcus unit 7 is provided with a pulse generator (not shown) capable of recognizing the amount of extension of the focus lens by the motor used as the lens drive source, and the controller 1 counts the number of pulses. The feeding amount is controlled. As a drive reference position of the focus lens, a position ahead of infinity on the infinity side, that is, a position at which focus is focused on infinity is set. For this reason, for example, if focusing is performed when the subject is at a shooting position of 2 m, the number of pulses from the reference position is tracked and counted, and the control is performed to extend beyond the infinite position to the in-focus position of 2 m. Be seen.

In this embodiment, the shooting tendency is taken into consideration when the focus lens is extended from the reference position to the focus position. That is, when there are many short-distance shots, if the focus lens is returned to the reference position and then the lens drive for focusing is performed again, the time required for lens drive becomes long. Moreover, the lens drive for close-up photography starts from the position where the reference position, which is the initial position, is focused to infinity, so if the reference position is kept in order to reduce the time required for lens drive, It is impossible to shoot because the shooting position is not in focus.

In this embodiment, the focus lens is positioned at a specific position different from the reference position. The specific position takes into consideration the focal length of the focus lens and the extension direction from the reference position, that is, whether the focus adjustment method of the focus lens is from the short distance side to the long distance side or the opposite method. It is set based on the frequency of selection of the shooting distance of the subject, and when a focus lens having a focal length of 28 to 105 mm is used, it is about 1 m on the 35 mm side and about 3 on the 105 mm side.
m, preferably 1.5 m on the 35 mm side and 3.5 m on the 105 mm side. The position on the long apex side is an example set by predicting a case in which a distant subject is often photographed, but it is not limited to this value. The specific position in the present embodiment does not necessarily match the position of the hyperfocal length, and is determined in consideration of the frequency of use and the extension direction (focus adjustment method).

In the control unit 1, the focus lens is positioned at a specific position, and the reference depth of field is set based on the focal length and aperture value when setting the specific position.
The following control is executed by using the reference depth of field. (1) The final depth of field obtained based on the photometric information and the focal length when the release switch is turned on and the shooting operation is performed is compared with the reference depth of field, and the shooting depth during shooting operation is compared. When it is determined that the depth of field is within the reference depth of field, shooting is performed without driving the focus lens. (2) When it is determined that the final depth of field is outside the reference depth of field, flashmatic calculation is performed and the depth of field obtained by the aperture value is used as the reference depth of field. Compared with the depth of field, if it is within the reference depth of field, flash photography is performed with the focus lens at a specific position left as it is. (3) When the focus adjustment method using the focus lens is a method of driving from the long distance side to the short distance side, the final depth of field is outside the depth of field, and the position of the focus lens is specified. When it is determined that the focus lens is closer to the position than the position, the focus lens is driven so as to enter the final depth of field without returning to the reference position. If it is determined to be on the far side, once return the focus lens to the reference position corresponding to the pulse application start position in the unit,
A pulse from the reference position to the position where the final depth of field is obtained is applied to the drive source of the focus unit to drive the focus lens to a position corresponding to the final depth of field. (4) When the focus adjustment method using the focus lens is a method in which the focus lens is driven from the short distance side to the long distance side, focus is determined when the position of the focus lens is closer to the specific distance. The lens is driven so as to be within the final depth of field without returning to the reference position.
Once if it is determined that the final depth of field is outside the depth of field and the position of the focus lens is closer to the specific position. After returning to the reference position described above, driving is performed to a position where the depth of field is reached. (5) When it is determined that the focus lens is on the near side or the far side of the specific position in the final depth of field, the specific position is set to the near side or the far side according to the determination result. Shift to the distance side. (6) Regarding the shift amount raised in (5) when the focus adjustment method is a method of driving the focus lens from the short distance side to the long distance side, the shift amount on the long distance side is smaller than the shift amount on the short distance side. To do.

With respect to the control procedure of the control unit 1, a little explanation will now be given. In the control of (1), if the final depth of field is within the reference depth of field, shooting is performed as it is to focus. The time lag required for driving the lens can be eliminated. In the control of (2), if the aperture value is updated by using the flashmatic method when the depth of field is not within the reference depth of field, and the depth of field according to the aperture value is within the reference depth of field. It is possible to prevent the focus lens from being driven by stroboscopic photography.

In the control of (3) and (4), when the drive direction of the focus lens is compatible with the focus adjustment method, there is a time lag caused by returning to the reference position by driving in that direction from a specific position. If it corresponds to a direction different from the driving direction in the focus adjustment method, it is possible to prevent lens rattling by returning to the reference position and driving to the position where the final depth of field is reached. It is possible to prevent an error in the lens position from occurring.

2 and 3 are schematic views showing the moving state of the focus lens for explaining this control. FIG. 3 shows a case where the focus adjustment method drives the lens from the long-distance side to the short-distance side, and specifies a specific position different from the reference position, that is, a position on the near-focus side or the long-focus side described above. The position is set as a position, the focus lens is positioned at that position, and the depth of field obtained at this position is stored in the control unit 1.

It is calculated from the final photometry data when the photographing operation is performed by the ON operation of the release switch SW2 while the photometry and the distance measurement when the photographing operation is performed by the ON operation of the release switch SW1 are repeated for a certain period of time. The final depth of field is calculated based on the aperture value and focal length
If the final depth of field is determined to be on the short distance side outside the depth of field at the specific position, it is the same as the driving direction in the adjustment method, so the lens is driven to the short distance side as it is (arrow in FIG. 3). (F1 direction). When it is determined to be on the far side, the driving direction in the adjusting method is opposite to the driving direction. Therefore, the focus lens at the specific position is temporarily returned to the reference position (indicated by arrow F2 in FIG. 3). Direction), and based on the number of pulses corresponding to the drive amount from the reference position, the focus lens is driven toward a position within the final depth of field (FIG. 3).
Middle, direction indicated by arrow F3).

On the other hand, FIG. 4 shows the case where the focus adjustment method drives the lens from the short distance side to the long distance side, and in this case, the final depth of field is set on the basis of the depth of field at a specific position. When the depth of field is outside the reference depth of field and it is determined to be on the long distance side, it is the same as the driving direction, and therefore the driving is performed in the same direction as the driving direction in the adjustment method (FIG. 4).
Middle, direction indicated by arrow F1 '). If it is judged to be on the short distance side, it is the opposite of the drive direction in the adjustment method,
Similar to the case described with reference to FIG. 3, after returning to the reference position once, it is driven to a position within the final depth of field (FIG. 4).
Middle, directions indicated by arrows F2 'and F3'). In the control of (5), by updating the shift amount, it is possible to reduce the drive amount at the time of the next lens drive by adapting to the frequently used photographing mode.

In the control of (6), the position error of the lens and the drive amount can be reduced by reducing the shift amount when the drive in the direction opposite to the drive direction in the focus adjustment method is required.

Since the present embodiment is configured as described above, the operation of the control unit 1 will be described below with reference to the flowchart shown in FIG. When the shooting operation is performed by turning on the release switches SW1 and SW2 when the focus lens is positioned at a specific position and is in a standby state (ST1), photometry and distance measurement are executed and each data is taken into the control unit 1. (ST2, ST3).

The control unit 1 calculates the final depth of field at the time of photographing operation from the data captured in steps ST2 and ST3 (ST4), and the final depth of field is a reference depth of field obtained at a specific position. When compared with the depth (ST5), if it is within the reference depth of field, the shutter is opened / closed in the step shown as shutter open / close in FIG. ST6).

If the depth of field is not within the standard depth of field in step ST5, flashmatic calculation is executed (S
T7), the final depth of field is again obtained by the aperture value obtained by the calculation, and the final depth of field is compared with the reference depth of field (ST8). If the final depth of field is within the reference depth of field in step ST8, forced stroboscopic photography is executed using the aperture value obtained by the flashmatic calculation (ST9), and the final depth of field is determined. If the depth is outside the standard depth of field paper, is the position of the focus lens at which the final depth of field is obtained forward or backward with respect to the drive direction in the focus adjustment method? Is determined (ST10). When it is determined that the direction is the forward direction, that is, the same as the drive direction in the focus adjustment method, the focus position is moved from the specific position to the drive direction as it is. Since the number of pulses is equivalent to the number of pulses, the number of pulses is read to perform position determination, the shift amount of the number of pulses is used as update data for the specific position, and the updated specific position is newly set (ST11). When the process of step ST11 is performed, shooting is performed in a state where the shutter is opened and closed to move to a position where the final depth of field is obtained (S).
T6).

When it is determined in step ST9 that the direction is the opposite direction, the focus lens is returned from the specific position to the reference position corresponding to the pulse application start position (ST1
2) The number of pulses applied from the reference position, in this case, the number of pulses that can set the position of the lens at which the final depth of field is obtained, is extended toward a position (ST1).
3).

When the process of step ST13 is completed, the photographing operation is executed by opening and closing the shutter (ST6). When the shutter is closed and the photographing is completed, step ST1
1 or the specific position updated in step ST13 is newly set, and the focus lens is positioned at the new specific position (ST14). When the focus lens is positioned at a new specific position, the film is wound when the shutter is closed (ST1
5) Prepare for the next shooting.

In the present embodiment as described above, a special configuration is achieved only by executing the procedure in the control section 1 by using the driving configuration of the lens used in the focus adjustment method, that is, the configuration for counting the extension pulse. It is possible to reduce the occurrence of a time lag due to the lens driving without adding the above.

[0035]

According to the first aspect of the present invention, the focus adjusting lens preset at the specific position is photographed with respect to the reference depth of field obtained for setting the specific position. As a result of comparison with the depth of field when the operation is performed, if the depth of field during the shooting operation is within the reference depth of field, it is possible to shoot without driving the lens. It is possible to eliminate a time lag when driving is required.

According to the second aspect of the present invention, when the depth of field at the time of shooting operation deviates from the reference depth of field, recalculation is performed by the aperture value obtained by executing flashmatic calculation. If the determined depth of field is within the reference depth of field, the lens drive is not performed by shooting with flash light without driving the focus adjustment lens, and the time lag that occurs during lens drive can be eliminated. It will be possible.

According to the third aspect of the present invention, when the focus adjustment method is a method of driving the lens from the long distance side to the short distance side, the depth of field at the time of shooting operation is the reference depth of field. If it is outside and it is judged that it is on the short distance side, it does not return the focus adjustment lens to the drive reference position, but it is driven in the same direction as the drive direction in the focus adjustment method, so that it can be driven to a position within the depth as it is. It is possible to eliminate the time lag that occurs when returning to the drive reference position and when driven from the reference position. Furthermore, if it is determined to be on the far side, it occurs when moving in the direction opposite to the drive direction of the focus adjustment method by returning to the reference position and driving to the position where the final depth of field is reached. It is possible to reduce the error in the position of the lens that is easy to perform.

According to the fourth aspect of the present invention, when the focus adjustment method is a method of driving the lens from the short distance side to the long distance side, the depth of field at the time of shooting operation is the reference depth of field. If it is outside and it is judged that it is on the far side, it does not return the focus adjustment lens to the drive reference position, but it is driven in the same direction as the drive direction in the focus adjustment method, so it will drive to the position that is within the depth as it is. It is possible to eliminate the time lag that occurs when returning to the drive reference position and when driven from the reference position. Furthermore, if it is determined to be on the short-distance side, it occurs when moving in the direction opposite to the drive direction in the focus adjustment method by returning to the reference position and then driving to the position where the final depth of field is reached. It is possible to reduce the error in the position of the lens that is easy to perform.

According to the fifth aspect of the invention, when it is determined that the position is on the short distance side or the long distance side, the specific position is shifted to each distance side, so that the photographing condition tendency frequently used by the user. In other words, by updating the specific position when using close-range shooting frequently or when using long-distance shooting frequently, it is possible to reduce the lens drive amount from that specific position and reduce the time lag. Becomes

According to the sixth aspect of the present invention, since the shift amount to the long distance side is made smaller than the shift amount to the short distance side, the lens is not moved in the direction in which the backlash is removed but in the direction in which the backlash is not removed. It is possible to suppress an error when the lens is driven by positioning the lens.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of a control unit used in an image capturing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining one of focus lens driving methods executed by the control unit shown in FIG.

FIG. 3 is a schematic diagram for explaining another one of the focus lens driving methods executed by the control unit shown in FIG.

FIG. 4 is a flowchart for explaining the operation of the control means shown in FIG.

[Explanation of symbols] 1 Control unit which is a main part of the control means used in the photographing apparatus 2 Photometric unit 3 ranging unit 6 Display device 7 Focus unit SW1, SW2 release switch

Claims (6)

[Claims] 1. A photographing apparatus comprising a distance measuring means, a photometric means and a lens driving means for driving a focus adjusting lens, wherein the focal point and the lens driving direction are associated with the focal point by the lens driving means in advance. When the adjustment lens is set to a specific distance position from the driving reference position and an operation for starting the photographing preparation operation is performed, the photometry and distance measuring means are repeatedly operated for a predetermined time to become the reference object field. Obtaining the depth, when an operation for shooting is performed during that, the depth of field is calculated based on the specific distance, the shooting aperture value calculated from the final photometric data, and the focal length.
An image pickup apparatus comprising a control means for performing image pickup as it is when a final depth of field during a shooting operation is within the reference depth of field. 2. A photographing device comprising a distance measuring means, a photometric means, a lens driving means for driving a focus adjusting lens, a light emitting means for performing flash photographing, and a charging means for the same. When the lens driving means sets the focus adjusting lens to a specific distance position from the driving reference position in correspondence with the driving direction and an operation for starting the photographing preparation operation is performed, the photometry and distance measurement are performed. When the operation for photographing is performed during that time by repeatedly operating the means for a certain period of time to obtain a reference depth of field, the specific distance, the photographing aperture value calculated from the final photometric data, and the focus. The depth of field is calculated based on the distance, and the flashmatic calculation is performed when the depth of field is outside the reference depth of field during the shooting operation. , If the depth of field based on the aperture value of the flashmatic is recalculated and this depth of field is within the standard depth of field, the standard depth of field is set under the required conditions. An image pickup apparatus, which is provided with a means for performing flash photography by using a light emitting means as it is by using a focus adjustment lens at a specified distance. 3. The photographing apparatus according to claim 1, wherein the control means uses a focus adjustment method driven from a long distance side to a short distance side as a focus adjustment method of the focus adjustment lens. In addition, the final depth of field is outside the reference depth of field, and the position of the focus adjustment lens (distance to the subject) is closer to the preset specific position. When it is determined, the focus adjustment lens is driven to a position within the depth without returning to the drive reference position, and the focus adjustment lens position (distance to the subject) is set from a specific position set in advance. Also, when it is determined that the lens is on the far side, the image pickup apparatus drives the focus adjustment lens from a drive reference position of the focus adjustment lens to a position within the depth. 4. The photographing apparatus according to claim 1, wherein the control means uses a focus adjustment system driven from a short distance side to a long distance side as a focus adjustment method of the focus adjustment lens. In addition, the final depth of field is outside the reference depth of field, and the position of the focus adjustment lens (distance to the subject) is on the far-distance side of the preset specific position. When it is determined, the focus adjustment lens is driven to a position within the depth without returning to the drive reference position, and the position of the focus adjustment lens (distance to the subject) is set from a specific position set in advance. Also, when it is determined that the focus adjustment lens is at a short distance, the focus adjustment lens is driven from a drive reference position of the focus adjustment lens to a position within the depth. 5. The photographing apparatus according to claim 3 or 4, wherein when the control means determines that the position of the focus adjustment lens is closer than the specific position, the specific position is closer to the specific position. The photographing apparatus is characterized in that, when it is determined to be on the far side, the specific position is shifted to the far side and used for the next final depth of field determination. 6. The photographing apparatus according to claim 4, wherein the control means reduces the amount of shift to the long distance side relative to the amount of shift to the short distance side when shifting the specific position. Imaging device.