JP2021156948A - Imaging device - Google Patents

Abstract

To provide an imaging device with which, while performing live view display between continuous shooting frames, it is possible to improve a maximum frame speed and reduce power consumption when the frame speed is lowered.SOLUTION: An imaging device (100) comprises: a front blade group (4) and a rear blade group (5) for opening/closing an aperture (1a) for exposure; a front drive member (7) and a rear drive member (8) for driving the front and the rear blade groups, respectively, between the open and the closed positions of the aperture; a front drive source (24) and a rear drive source (25) for driving the front and the rear drive members, respectively; control means (209) for controlling the front and the rear drive sources; and an imaging element (203). The control means switches, on the basis of imaging conditions, between a first mode in which energization to the front drive source and energization to the rear drive source are sequentially performed before reading-out of electric charges from the imaging element is completed and a second mode in which energization to the rear drive source is performed after reading-out of electric charges from the imaging element is completed.SELECTED DRAWING: Figure 6

Description

The present invention relates to an imaging device including a shutter device such as a focal plane shutter.

Conventionally, in a shutter device such as a focal plane shutter, if light is applied while reading an output signal from the image sensor, it causes noise. Therefore, the image sensor is charged by charging the front curtain and the rear curtain of the shutter device in order. It is known to control so that it is not exposed to light. Patent Document 1 describes an imaging device that performs live view display between continuous shooting frames to improve subject tracking and focusing performance, and performs imaging with low vibration and low noise by using electronic front curtain scanning with an image sensor. It is disclosed.

JP-A-2018-84772

However, the image pickup apparatus disclosed in Patent Document 1 charges the rear curtain, starts to open the shutter opening, and starts the live view display after reading the accumulated charge by the image pickup. Therefore, it is difficult to improve the continuous shooting frame speed.

On the other hand, when performing live view display between continuous shooting frames, if the front curtain and rear curtain are uniformly charged so as not to shine light on the image sensor and then shift to live view display, the live view display will eventually be displayed. Run the front curtain when shifting to. Therefore, depending on the shooting conditions, the power consumption for charging the front curtain is wasted.

Therefore, an object of the present invention is to provide an imaging device capable of improving the maximum frame speed while performing live view display between continuous shooting frames and reducing power consumption when the frame speed is slowed down.

The image sensor as one aspect of the present invention has the front blade group and the rear blade group that open and close the opening for exposure, and the front blade group and the rear blade group between the opening position and the closing position of the opening, respectively. A front drive member and a rear drive member to be driven, a front cam gear and a rear cam gear for charging the front drive member and the rear drive member, and a front drive source and a front drive source for rotating the front cam gear and the rear cam gear, respectively. It has a rear drive source, a control means for controlling the front drive source and the rear drive source, and an image sensor that photoelectrically converts a subject image and outputs an image signal, and the control means is based on shooting conditions. The first mode in which the first drive source and the second drive source are sequentially energized before the reading of the electric charge from the image sensor is completed, and the reading of the electric charge from the image sensor are completed. Later, the mode is switched to the second mode in which the rear drive source is energized.

Other objects and features of the present invention will be described in the following embodiments.

According to the present invention, it is possible to provide an imaging device capable of improving the maximum frame speed while performing live view display between continuous shooting frames and reducing power consumption when the frame speed is slowed down.

It is a perspective view of the image pickup apparatus which mounted the shutter apparatus in this embodiment. It is a block diagram of the image pickup apparatus in this embodiment. It is an exploded perspective view of the shutter device in this embodiment. It is an exploded perspective view of the shutter device in this embodiment. It is a top view of the shutter device in the shooting standby state in this embodiment. It is a perspective view of the drive member and a cam gear in this embodiment. It is a timing chart which shows the operation of the shutter device and the image sensor in the first set operation mode in this embodiment. It is a top view of the shutter device in the traveling standby state in this embodiment. It is a top view of the shutter device during the exposure operation in this embodiment. It is a top view of the shutter device just before the set operation in this embodiment. It is a top view of the shutter device during the set operation in the first set operation mode in this embodiment. It is a top view of the shutter device just before the traveling of the leading drive member during a set operation in this embodiment. It is a timing chart which shows the operation of the shutter device and the image sensor in the 2nd set operation mode in this embodiment. It is a top view of the shutter device during the set operation of the rear drive member in the second set operation mode in this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the image pickup apparatus 100 provided with the shutter apparatus (focal plane shutter) 202 according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of the image pickup apparatus 100. On the upper surface of the image pickup apparatus 100, a power button 110, a release button 130, and an accessory shoe 140 for attaching a photographing accessory such as a strobe device are provided. The lens mount 150 is a mounting portion for an imaging lens (not shown). The image pickup device 100 is a mirrorless type image pickup device without a reflex mirror, and the shutter curtain is open in a state of waiting for shooting for live view display. Therefore, as shown in FIG. 1, the image pickup surface of the image pickup device 203 is exposed when the image pickup lens is removed.

FIG. 2 is a block diagram of the image pickup apparatus 100. The shutter device 202 is provided between an image pickup lens 201 that forms an image of light from a subject on a shooting optical path and an image pickup element 203 such as a CMOS image sensor. The shutter device 202 adjusts the time for exposing the image sensor 203 in conjunction with the electronic front curtain operation of the image sensor 203. The image pickup element 203 photoelectrically converts the subject image formed by the image pickup lens 201 and outputs an image signal (analog image signal). The analog image signal output from the image sensor 203 is converted into a digital signal by AFE (Analog Front End) 204. The digital image signal output from the AFE204 is subjected to various image processing and compression / decompression processing by the DSP (Digital Signal Processor) 205. The recording medium 206 records the image data processed by the DSP 205. A liquid crystal display (LCD) or the like is used in the display unit 207 to display captured images, various menu screens, and the like. The TG (Timing Generator) 208 supplies a drive signal to the image sensor 203. The RAM 210 is connected to the DSP 205 and temporarily stores image data and the like. The shutter drive circuit 211 drives the shutter device 202. The CPU 209 controls the AFE204, the DSP205, the TG208, and the shutter drive circuit 211. The lens control means 212 outputs lens information such as the focal length, aperture diameter, and pupil diameter of the image pickup lens 201, and the distance between the pupil and the image pickup element 203 to the CPU 209, and drives the aperture, the lens, and the like according to the control by the CPU 209. do.

Next, the shutter device 202 according to the present embodiment will be described with reference to FIGS. 3 to 5. FIG. 3A is an exploded perspective view of the shutter device 202 viewed from the side where the image sensor 203 is attached (image sensor side), and FIG. 3B is the side where the image sensor 201 is attached (subject side) of the shutter device 202. It is an exploded perspective view seen from. FIG. 4A is a plan view of the shutter device 202 in a shooting standby state as viewed from the image sensor side, and FIG. 4B is a plan view of the shutter device 202 as viewed from the subject side. FIG. 5A is a perspective view of the front drive member 7 and the front cam gear 22, and FIG. 5B is a perspective view of the rear drive member 8 and the rear cam gear 23.

A partition plate 2 and a cover plate 3 are sequentially attached to the subject side of the shutter base plate 1 at predetermined intervals. Apertures (openings) 1a, 2a, and 3a having similar shapes are formed on the three plate members of the shutter base plate 1, the partition plate 2, and the cover plate 3, and a rectangular exposure in which these three apertures are overlapped is formed. The opening defines the luminous flux passing through the shutter. Further, two blade chambers are formed between these three plate members, and shutter blades including a light-shielding blade and a blade arm are individually arranged as a front blade group 4 and a rear blade group 5 in the blade chambers. .. The front blade group 4 and the rear blade group 5 open and close the exposure openings (1a to 3a).

An auxiliary base plate 6 made of metal is fastened to the shutter base plate 1 by screws in order to improve the strength of the shutter base plate 1 and to crimp various metal shafts. A plurality of shafts 6a, 6b, 6c, 6d, 6e, and 6f are erected on the auxiliary base plate 6 on the image sensor side. A front driving member 7, a rear driving member 8, a front locking member 9, and a rear locking member 10 are rotatably attached to the shafts 6a, 6b, 6c, and 6d, respectively. Further, a front drive source 24 such as a DC motor and a rear drive source 25 are respectively fastened to the subject side of the auxiliary base plate 6 with screws.

The front drive member 7 and the rear drive member 8 drive the front blade group 4 and the rear blade group 5 between the open position and the closed position of the opening 1a, respectively. The front cam gear 22 and the rear cam gear 23 charge the front drive member 7 and the rear drive member 8, respectively. The front drive source 24 and the rear drive source 25 are connected to and rotated by the front cam gear 22 and the rear cam gear 23, respectively. The front drive source 24 and the rear drive source 25 are controlled by the control means (CPU 209) using the shutter drive circuit 211.

A gear base plate 26 is fastened to the subject side of the auxiliary base plate 6 with screws. The front cam gear 22 and the rear cam gear 23 are rotatably attached to shafts 26a and 26b erected on the image sensor side of the gear base plate 26, respectively. The front reduction gear 27 is rotatably supported on the shafts 26c and 26e on the image pickup element side of the gear base plate 26, and the rear reduction gear 28 is rotatably supported on the shafts 26d and 26f. The output shaft 24a, the front reduction gear 27, and the front cam gear 22 of the front drive source 24, and the output shaft 25a, the rear reduction gear 28, and the rear cam gear 23 of the rear drive source 25 are engaged with each other. The first reduction gear 27 transmits the driving force from the first drive source 24 to the first cam gear 22. The rear reduction gear 28 transmits the driving force from the rear drive source 25 to the rear cam gear 23. With such a configuration, the torques of the front drive source 24 and the rear drive source 25 can be transmitted to the front cam gear 22 and the rear cam gear 23, respectively. The front drive source 24 and the rear drive source 25 are configured to be usable for both forward rotation and reverse rotation. In the present embodiment, the direction in which the front cam gear 22 and the rear cam gear rotate counterclockwise in FIG. 4A is defined as forward rotation.

Here, the lines AA in FIG. 4A are lines passing through the center of the opening, and are the distance from the rotation axis (axis 6a) of the front drive member 7 and the rotation axis (axis 6b) of the rear drive member 8. ) Is the same as the distance from the opening center line. As the parts for driving the front blade group 4, the shaft 26a, which is the rotation shaft of the front cam gear 22, the shaft 6a, which is the rotation shaft of the front drive member 7, and the rotation shaft of the front reduction gear 27, are arranged in order of proximity to the wire AA. The shaft 26c and the output shaft 24a of the leading drive source 24 are arranged. On the other hand, as the parts for driving the rear blade group 5, the shaft 26b which is the rotation shaft of the rear cam gear 23, the shaft 6b which is the rotation shaft of the rear drive member 8, and the rotation shaft of the rear reduction gear 28 are arranged in the order closer to the lines AA. The shaft 26d and the output shaft 25a of the rear drive source 25 are arranged. That is, in the short side direction of the opening 1a, the rotation shafts (shafts 26a, 26b) of the front cam gear 22 and the rear cam gear 23 are closer to the opening center than the rotation shafts (shafts 26c, 26d) of the front reduction gear 27 and the rear reduction gear 28. It is located near the line (line AA).

In such an arrangement, the shutter device 202 is operated by two drive sources, the front drive source 24 and the rear drive source 25, and the torque required to drive the front blade group 4 and the torque required to drive the rear blade group 5 are combined. This is possible by dispersing the above and reducing the size of the front cam gear 22 and the rear cam gear 23. As a result, the entire shutter device 202 can be miniaturized.

The front drive member 7 and the rear drive member 8 are urged counterclockwise when viewed from the image sensor side by the urging forces of the front drive spring 12 and the rear drive spring 13, respectively. On the other hand, the front drive member 7 and the rear drive member 8 are rotated clockwise by the front cam gear 22 and the rear cam gear 23 against the urging force of the front drive spring 12 and the rear drive spring 13. Then, at the set position, the locking portions 7a and 8a provided on the front driving member 7 and the rear driving member 8 are engaged with the locking portions 9a and 10a of the front locking member 9 and the rear locking member 10. As a result, the front drive member 7 and the rear drive member 8 are locked. Further, the front drive member 7 and the rear drive member 8 are provided with drive pins 7b and 8b, respectively. These penetrate the elongated holes 1b and 1c, the elongated holes 6g and the elongated holes 6h, and the elongated holes 3b and the elongated holes 3c, which are three sets of elongated holes of the shutter base plate 1, the auxiliary base plate 6, and the cover plate 3. , It is engaged with the elongated holes 4c and 5c of the blade arms 4a and 5a. A roller 14 and a roller 15 are rotatably attached to the leading drive member 7. A roller 16 and a roller 17 are rotatably attached to the rear drive member 8. The front cam gear 22 sets the front drive member 7 via the rollers 14 and 15, and the rear cam gear 23 sets the rear drive member 8 via the rollers 16 and 17, respectively.

Here, in the configuration of the present embodiment, the front cam gear 22 is formed with cam surfaces 22a and 22b, and the rear cam gear 23 is formed with cam surfaces 23a and 23b, respectively. Then, the two rollers 14, 15, 16 and 17 attached to the front drive member 7 and the rear drive member 8 are sequentially contacted with the two cam surfaces to perform the set operation. As a result, the amount of rotation of the front drive member 7 and the rear drive member 8 and the front cam gear 22 and the rear cam gear 23 during the set operation is equalized, so that the maximum load during the set operation can be reduced. .. By the way, depending on the permissible tolerances of the related parts, there may be some that cannot bring the front drive member 7 and the rear drive member 8 to the set position within the permissible range. In that case, the set positions of the front drive member 7 and the rear drive member 8 can be adjusted by exchanging the rollers 15 and 17.

The blade phase detecting means 29, 30 and the phase detecting means (cam phase detecting means) 31, 32 are non-contact optical phase detecting means, and are attached to the holding base plate 11 arranged on the image pickup element side of the auxiliary base plate 6. ing. In this embodiment, a photo interrupter is used as the blade phase detecting means 29 and 30 and the phase detecting means 31 and 32. The blade phase is detected by determining the light-shielding state of the blade phase detection means 29, 30 by the detected portions 7f, 8f of the front drive member 7 and the rear drive member 8. The phase of the cam phase is detected by determining the light-shielding state of the phase detecting means 31 and 32 by the detected portions 22c and 23c of the front cam gear 22 and the rear cam gear 23. In this embodiment, the phase detection means 31 and 32 use two photo interrupters, respectively, to determine the phase.

The front blade group 4 and the rear blade group 5 of the present embodiment have two sets of blade arms 4a, 4b, 5a, 5b and four sets of light-shielding blades 4d, 4e, 4f, 4g, 5d, 5e, 5f, respectively. It is composed of 5 g. In the front blade group 4, the two blade arms 4a and 4b are rotatably pivotally attached to the axes 6i and 6j on the subject side of the auxiliary base plate 6. The four blades 4d, 4e, 4f, and 4g are pivotally supported with respect to the blade arms 4a and 4b via a connecting shaft 33. As described above, the blade arm 4a is formed with a long hole 4c, and the drive pin 7b of the leading drive member 7 is engaged with the long hole 4c.

In the rear blade group 5, the two blade arms 5a and 5b are rotatably pivotally attached to the axes 6k and 6l on the subject side of the auxiliary base plate 6. Then, four light-shielding blades 5d, 5e, 5f, and 5g are pivotally supported with respect to the blade arms 5a and 5b via a connecting shaft 33. Further, as described above, the blade arm 5a is formed with a long hole 5c, and the drive pin 8b of the rear drive member 8 is engaged with the long hole 5c.

Next, with reference to FIGS. 4 to 13, the shooting operation during continuous shooting of the present embodiment will be described. The set operation of the present embodiment is divided into two modes according to the shooting conditions (shooting conditions). However, the operation is different only in the set operation during a series of shooting operations. FIG. 6 is a timing chart showing the operations of the shutter device 202 and the image sensor 203 in the first set operation mode (first mode). FIG. 12 is a timing chart showing the operations of the shutter device 202 and the image sensor 203 in the second set operation mode (second mode). (1) to (11) in FIG. 6 and (1) to (10) in FIG. 12 correspond to each operation state described below.

FIG. 4 is a plan view showing a shooting standby state when the shutter device 202 is viewed from the image sensor side (FIG. 4 (a)) and the subject side (FIG. 4 (b)). FIG. 7 is a plan view showing a traveling standby state after the rear curtain set is released when the shutter device 202 is viewed from the image sensor side (FIG. 7 (a)) and the subject side (FIG. 7 (b)). FIG. 8 is a plan view showing a state in which the rear blades are traveling during the exposure operation when the shutter device 202 is viewed from the image sensor side (FIG. 8A) and the subject side (FIG. 8B). FIG. 9 is a plan view showing a state of the shutter device 202 as viewed from the image sensor side (FIG. 9 (a)) and the subject side (FIG. 9 (b)) after the rear blades have completed traveling and immediately before the set operation. FIG. 10 is a plan view showing a state during the set operation in the first set operation mode when the shutter device 202 is viewed from the image sensor side (FIG. 10 (a)) and the subject side (FIG. 10 (b)). FIG. 11 is a plan view showing a state immediately before traveling of the front blades during the set operation when the shutter device 202 is viewed from the image sensor side (FIG. 11 (a)) and the subject side (FIG. 11 (b)). FIG. 13 is a plane showing a state in which the rear drive member is being set in the second set operation mode when the shutter device 202 is viewed from the image sensor side (FIG. 13 (a)) and the subject side (FIG. 13 (b)). It is a figure.

In the shooting standby state of FIG. 6 (1), as shown in FIG. 4 (a), the front drive member 7 is held in the running complete state, the rear drive member 8 is held at the cam top position of the rear cam gear 23, and the rear drive member 8 is held. It is an overcharged state having a gap between the locked portion 8a of the above and the locking portion 10a of the rear locking member 10. Since the front blade group 4 and the rear blade group 5 are retracted from the exposure aperture, the subject luminous flux passes through the exposure aperture. In the image pickup apparatus 100, a live view image pickup operation is performed, and a subject image incident on the image pickup device 203 is displayed on the display unit 207.

When the release button 130 of the image pickup apparatus 100 is pressed, the release operation is started (FIG. 6 (2)), and the rear drive member 8 is released from the set. The rear drive source 25 is energized in the forward rotation direction, and the rear cam gear 23 is rotated counterclockwise in FIG. 4A via the rear reduction gear 28. The roller 17 is separated from the cam surface 23b of the rear cam gear 23, the rear drive member 8 is integrated with the rear blade group 5, and is slightly rotated counterclockwise in FIG. 4A to release the overcharge state. There is no gap between the locked portion 8a of the rear driving member 8 and the locking portion 10a of the rear locking member 10, and the locked portion 8a of the rear driving member 8 becomes the locking portion 10a of the rear locking member 10. By engaging, the rear drive member 8 stops at the traveling start position. After the rear cam gear 23 retracts from the traveling range of the rear driving member 8 (cam bottom), the rear drive source 25 is stopped by detecting the stop phase of the cam phase detecting means 32, and the traveling standby state of FIG. 7 is established (FIG. 6). (3)).

After resetting all the pixels of the image sensor 203 (FIG. 6 (4)), the electronic front curtain scanning is started (FIG. 6 (5)). The electronic front curtain scanning has a scanning pattern that matches the traveling characteristics of the rear blade group 5. After the corresponding time elapses at the set shutter seconds, the unlocking member (not shown) hits the pushing portion 10b of the rear locking member 10 to move the rear locking member 10 around the shaft 6d in FIG. 7. Rotate it counterclockwise in (a) to disengage the locked portion 8a of the rear drive member 8 (FIG. 6 (6)). Then, from the running standby state shown in FIG. 6, the rear drive member 8 is rapidly rotated around the shaft 6b in the counterclockwise direction of FIG. 7 (a) by the urging force of the rear drive spring 13. As a result, the rear drive pin 8b rotates the blade arm 5a in the clockwise direction of FIG. 7B, so that the rear blade group 5 covers the exposure opening while reducing the amount of mutual overlap (FIG. 8). .. When the exposure operation is continued and the slit forming edge 5h of the blade 5d of the rear blade group 5 recedes below the exposure opening, the rear drive pin 8b comes into contact with a stop member (not shown), and the rear drive member 8 is stopped. Be done. FIG. 9 shows the blade traveling completion state performed in this way. When the traveling of the rear blade group 5 is completed and the image sensor 203 is completely shielded from light, the charge read-out scanning is started (FIG. 6 (7)).

A set operation is performed after a predetermined time has elapsed from the completion of traveling of the rear blade group 5 (FIG. 6 (8)). As described above, the set operation of the present embodiment is divided into two modes according to the shooting conditions (shooting conditions). First, the first set operation mode will be described.

After a predetermined time from the completion of traveling of the rear blade group 5, the front drive source 24 is energized in the forward rotation direction (FIG. 6 (8)), and the front cam gear 22 is rotated counterclockwise in FIG. 9 (a) around the shaft 26a. It is rotated. Along with this, the leading drive member 7 comes into contact with the leading cam gear 22 and is rotated clockwise in FIG. 9A around the shaft 6a while resisting the urging force of the leading cam gear 12. After a predetermined time from the start of energization of the front drive source 24, before the front drive member 7 reaches the cam top of the front cam gear 22, the rear drive source 25 is energized in the forward rotation direction (FIG. 6 (9)), and the rear cam gear is energized. 23 is rotated counterclockwise in FIG. 9 (a) around the shaft 26b. Along with this, the rear drive member 8 comes into contact with the rear cam gear 23 and is rotated clockwise in FIG. 9A around the shaft 6b while resisting the urging force of the rear drive spring 13. FIG. 10 shows a state during the set operation performed in this way. When the first drive member 7 passes through the cam top of the first cam gear 22 and continues to rotate, the locked portion 7a of the first drive member 7 engages with the locking portion 9a of the first locking member 9, thereby causing the first. The drive member 7 stops at the traveling start position. After that, the front cam gear 22 retracts from the traveling range of the front drive member 7 (cam bottom), and then the phase detecting means 31 detects the stop phase and stops the front drive source 24. Similarly, the rear drive member 8 also passes through the cam top of the rear cam gear 23 and continues to rotate, and the locked portion 8a of the rear drive member 8 engages with the locking portion 10a of the rear locking member 10. , The rear drive member 8 stops at the traveling start position. After that, the rear cam gear 23 retracts from the traveling range of the rear drive member 8 (cam bottom), and then the cam phase detection means 32 detects the stop phase and stops the rear drive source 25.

On the other hand, the movements of the front blade group 4 and the rear blade group 5 at this time are as follows. The blade arm 4a is rotated counterclockwise in FIG. 9B by the front drive pin 7b of the front drive member 7, and the blade 4d, the blade 4e, the blade 4f, and the blade 4g are moved upward while reducing mutual overlap. Move to. Further, the rear drive pin 8b of the rear drive member 8 causes the blade arm 5a to rotate counterclockwise in FIG. 9B, so that the blades 5d, the blades 5e, the blades 5f, and the blades 5g overlap each other. While moving upward. Then, when the front blade group 4 is expanded to completely cover the exposure opening and the rear blade group 5 is superimposed and stored at a position above the exposure opening, the rotation of the front drive member 7 and the rear drive member 8 is stopped. do. At this time, since the image sensor 203 is in the middle of reading and scanning the electric charge, the exposure aperture must be shielded from light. Therefore, it is necessary to set the time difference between the start of energization of the front drive source 24 and the rear drive source 25 so that a sufficient amount of overlap during the set operation of the front blade group 4 and the rear blade group 5 can be secured. The time difference between the start of energization of the front drive source 24 and the rear drive source 25 may be sufficiently secured. For example, based on the detection result of the blade phase detection means 29, the front blade group 4 has moved to a predetermined position. As a trigger, the rear drive source 25 may be configured to start energization. As a result, the continuous shooting frame speed can be improved while avoiding the risk of re-exposure during the read-out scanning of the charge of the image sensor 203.

Further, in order to improve the continuous shooting frame speed, it is preferable to start the live view image pickup operation of the image pickup device 203 as soon as possible. Therefore, in the present embodiment, in the above-mentioned set operation, at the timing when the three conditions of reaching the cam bottom of the front drive member 7, reaching the cam top of the rear drive member 8, and completing the reading of the electric charge of the image sensor 203 are satisfied. The running of the front blade group 4 is started. FIG. 11 shows a state (FIG. 6 (10)) immediately before the traveling of the front blade group 4 performed in this way.

Here, the details of the traveling of the front blade group 4 are as follows. When the unlocking member (not shown) collides with the pushing portion 9b of the first locking member 9, the first locking member 9 is rotated around the shaft 6c in the counterclockwise direction in FIG. The locking portion 7a of the drive member 7 is disengaged. As a result, the leading drive member 7 rapidly rotates around the shaft 6a in the counterclockwise direction in FIG. 11A due to the urging force of the leading drive spring 12. As a result, the front drive pin 7b rotates the front blade arm 4a in the clockwise direction in FIG. 11B, so that the front blade group 4 opens the exposure opening while increasing the amount of mutual overlap. When the slit forming edge 4h of the light-shielding blade 4d of the front blade group 4 recedes below the exposure opening, the front drive pin 7b comes into contact with a stop member (not shown), the front drive member 7 is stopped, and the front blade group The running of 4 is completed, and the running standby state of FIG. 7 is reached.

When the front blade group 4 travels, waiting for the rear drive member 8 to reach the cam top is because the traveling operation of the front blade group 4 and the setting operation of the rear blade group 5 are performed in opposite directions at the same time. This is to prevent the front blade group 4 and the rear blade group 5 from coming into contact with each other and being damaged. In the timing chart of FIG. 6, the order of completion of reading the electric charge of the image sensor 203, the arrival of the cam bottom of the front drive member 7, and the arrival of the cam top of the rear drive member 8 is not limited to this order. Regardless of the order, the traveling of the front blade group 4 is started at the timing when the three conditions of reaching the cam bottom of the front driving member 7, reaching the cam top of the rear driving member 8, and completing the reading of the electric charge of the image sensor 203 are satisfied. If it is configured, the same effect can be obtained.

When the traveling of the front blade group 4 is completed, the image sensor 203 starts the live view image pickup operation, and preparations for shooting the next frame are made (FIG. 6 (11)). When the preparation for shooting the next frame is completed, the process returns to FIG. 6 (1), and thereafter, a series of shooting operations from FIG. 6 (1) to FIG. 6 (11) are repeated.

Next, the second set operation mode will be described with reference to FIGS. 12 and 13. After the traveling of the rear blade group 5 is completed, when the reading of the electric charge of the image sensor 203 is completed, the rear drive source 25 is energized in the normal rotation direction (FIG. 12 (8)), and the rear cam gear 23 is shown around the shaft 26b. In 9 (a), it is rotated counterclockwise. Along with this, the rear drive member 8 comes into contact with the rear cam gear 23 and is rotated clockwise in FIG. 9A around the shaft 6b while resisting the urging force of the rear drive spring 13 (FIG. 12 (9)). ). FIG. 13 shows a state during the set operation performed in this way. As described above, in the second set operation mode, by waiting for the completion of reading the electric charge of the image sensor 203, the charging operation and the traveling operation of the leading drive member 7 required in the first set operation mode become unnecessary. .. Therefore, the power consumption of the image pickup apparatus 100 can be suppressed. On the other hand, the time required for the set operation is longer in the second set operation mode than in the first set operation mode. Therefore, the continuous shooting frame speed in the second set operation mode is slower than that in the first set operation mode.

As described above, in the present embodiment, the control means (CPU209) switches between the first mode (first set operation mode) and the second mode (second set operation mode) based on the shooting conditions. .. The first mode is a mode in which the front drive source 24 is energized and the rear drive source 25 is energized in sequence before the reading of the electric charge from the image sensor 203 is completed. The second mode is a mode in which the rear drive source 25 is energized after the charge reading from the image sensor 203 is completed (the front drive source 24 is energized after the charge reading from the image sensor is completed). This is a mode in which the rear drive source is energized and the live view is displayed.

Preferably, the shooting condition is a condition relating to the frame speed of continuous shooting. More preferably, the control means switches to the first mode when the frame speed is faster than the predetermined frame speed, and switches to the second mode when the frame speed is slower than the predetermined frame speed.

Preferably, the shooting conditions are conditions relating to continuous shooting or single shooting. More preferably, the control means switches to the first mode when performing continuous shooting, and switches to the second mode when performing single shooting.

Preferably, the shooting condition is a condition relating to a silent mode in which the mechanical operation noise is small. More preferably, the control means switches to the first mode when the imaging device is not set to the silent mode, and switches to the second mode when the imaging device is set to the silent mode.

According to the present embodiment, it is possible to provide an image pickup apparatus capable of improving the maximum frame speed while performing live view display between continuous shooting frames and reducing power consumption when the frame speed is slowed down.

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 modifications can be made within the scope of the gist thereof.

4 Front blade group 5 Rear blade group 7 Front drive member 8 Rear drive member 22 Front cam gear 23 Rear cam gear 24 Front drive source 25 Rear drive source 100 Image sensor 203 Image sensor 209 CPU (control means)

Claims (8)

A group of front blades and a group of rear blades that open and close the opening for exposure,
A front drive member and a rear drive member that drive the front blade group and the rear blade group between the open position and the closed position of the opening, respectively.
The front cam gear and the rear cam gear that charge the front drive member and the rear drive member, respectively.
A front drive source and a rear drive source that are connected to and rotated by the front cam gear and the rear cam gear, respectively.
A control means for controlling the first drive source and the second drive source,
It has an image sensor that photoelectrically converts a subject image and outputs an image signal.
Based on the imaging conditions, the control means has a first mode in which the front drive source is energized and the rear drive source is energized in sequence before the reading of the electric charge from the image sensor is completed, and the image pickup. An image pickup apparatus comprising switching from a second mode in which the rear drive source is energized after the reading of the electric charge from the element is completed. The imaging device according to claim 1, wherein the photographing condition is a condition relating to a frame speed of continuous shooting. The control means
When the frame speed is faster than the predetermined frame speed, the mode is switched to the first mode.
The imaging device according to claim 2, wherein when the frame speed is slower than the predetermined frame speed, the mode is switched to the second mode. The imaging device according to claim 1, wherein the photographing conditions are conditions relating to continuous shooting or single shooting. The control means
When performing the continuous shooting, the mode is switched to the first mode.
The imaging device according to claim 4, wherein when performing the single-shot photography, the mode is switched to the second mode. The imaging device according to claim 1, wherein the photographing condition is a condition relating to a silent mode. The control means
If the imaging device is not set to the silent mode, the mode is switched to the first mode.
The imaging device according to claim 6, wherein when the imaging device is set to the silent mode, the mode is switched to the second mode. In the second mode, the control means energizes the post-drive source without energizing the pre-drive source after the reading of the electric charge from the image sensor is completed, and displays a live view. The image pickup apparatus according to any one of claims 1 to 7, wherein the image pickup apparatus is performed.

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