JP2005102199A - Imaging apparatus and its control method, and control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of tracing a subject, viewing a display screen and preventing image flickering on the display screen. <P>SOLUTION: An imaging device 13 receives light from the object through lenses for a lens all-group unit 207 and outputs a signal. A driving ring 204 is rotated by the driving force of an AF motor 114 and can move the unit 207 in the optical-axis direction. A focus is adjusted on the basis of the signal output from the imaging device 13 by moving the unit 207. An LCD 14 displays an image on the basis of the signal output from the imaging device 13. When the unit 207 is moved in the delivery direction, the display of the LCD 14 is formed in a through-display, and the through-display of the LCD 14 is limited until the unit 207 is inverted, moved to a putting-in and stopped. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an imaging apparatus such as a silver salt camera, an electronic camera, a digital camera, and a video camera, a control method thereof, and a control program for executing the control method.

  Conventionally, in a camera in which a lens is retracted, when a lens is extended, zooming and focusing are generally performed by the extension mechanism. In such a camera feeding mechanism, a cam is dug in an annular drive ring to rotate the drive ring, while a member that holds the lens is provided with a straight-ahead mechanism so that the lens does not rotate. A method of moving in the direction of the optical axis is often used. However, in this method of moving the drive ring, high accuracy is required for the position of the focus lens and zoom lens in the optical axis direction as the imaging means such as a CCD is downsized and the number of pixels is increased.

  On the other hand, when the lens is extended from the retracted lens, it is easy for the user to touch the lens barrel from the outside. Therefore, a sturdy lens barrel that does not break even when touched and does not move is required. However, if a lens barrel is made rugged, the load on the actuator when the lens is extended will be large. For this reason, a DC motor or a stepping motor is used as the actuator, and a large number of gears are used to drive the lens by increasing the torque by decelerating at a reduction ratio of several hundred times.

  However, when a force is applied to each member of the camera, a slight deformation or the like occurs in these members due to the backlash of each gear, the drive ring, the back of the cam groove and the cam pin, and as a result, when driving the lens Depending on the driving direction, a reciprocal difference occurs in the lens state. As the reciprocal difference, a relatively simple hysteresis with respect to the position in the optical axis direction, and a shift or a tilt of the lens due to the movement of the lens in the direction perpendicular to the optical axis and the rotation direction occur.

  In order to control the lens position with high accuracy, the lens cannot be controlled to an accurate position without taking the above-mentioned hysteresis into account, so a sensor that can detect the absolute position of the lens is attached or the lens is driven. When stopping, it always moves from one direction and stops. In the case of moving in the opposite direction, a hiss removal operation is performed in which the vehicle is moved slightly past the planned stop position and then reversed to return to the same amount and stopped at the stop position. In addition, when there is a reciprocal difference between the lens shift and the tilt, the image formed by the lens changes, so that the image shake occurs when the driving direction of the lens is reversed.

  As one of the technologies of an imaging device that performs focus adjustment based on the imaging signal, the image before capturing the signal from the image sensor during autofocusing is stored for focus adjustment, and the stored image is displayed as an image during focus adjustment. A technique for displaying on a display screen of means has been proposed (see, for example, Patent Document 1). Displaying the image output from the image sensor on the image display means is referred to as through display. For example, when the subject has a movement, the display image is changed according to the movement. Displaying the limited and stored image on the screen is called freeze display. For example, even when the subject has a movement, the stored image is displayed regardless of the movement.

In addition, as so-called hill-climbing autofocus (AF), when the focus evaluation value, which is the high-frequency component data of the frequency of the imaging signal output from the imaging device, is reduced, the through display is stopped and freeze display is performed. A technique for performing through display when the focus evaluation value is increasing is disclosed (for example, see Patent Document 2). As a result, only an in-focus image with a high focus evaluation value is displayed on the display screen, and an out-of-focus image is not displayed.
Japanese Patent No. 3302132 JP 2003-32521 A

  However, the above prior art has the following problems.

  If the display is always frozen during focus adjustment, it is difficult to follow the subject while viewing the display screen when shooting a moving subject. Also, when the freeze evaluation is displayed when the focus evaluation value is lowered, it is also difficult to follow the subject from the display screen when the subject is moving away from or approaching diagonally. Is desirable.

  In particular, in the case of the hill-climbing AF described above, in order to detect the in-focus direction, it is necessary to move the focus lens back and forth violently in a short time, such as wobbling. However, when displaying through only when the focus evaluation value rises, if there is a reciprocal difference in lens shift or tilt, it is possible to display through regardless of which direction the lens is moving. There is a problem that the display image fluctuates in the vicinity of the apex of the focus evaluation value, which causes discomfort to the user.

  In view of the above-described conventional problems, an object of the present invention is to provide an imaging apparatus, a control method thereof, and a control program capable of following a subject while viewing a display screen and preventing image fluctuations from being displayed on the display screen. There is to do.

  In order to achieve the above object, an imaging apparatus according to claim 1 is an imaging device that receives light from a subject through a lens unit and outputs a signal, and a lens movement that can move the lens unit in an optical axis direction. Means, adjusting means for adjusting the focus based on a signal output from the imaging means as the lens unit moves, display means for displaying an image based on the signal output from the imaging means, and the lens When the unit is moved in the first direction, display is made on the display means, the lens unit is reversed from the first direction to the second direction, and then the lens unit is moved and stopped. And control means for controlling to limit the display of the display means.

  According to a second aspect of the present invention, in the imaging device according to the first aspect, the limitation on the display of the display unit in the control unit is to continue displaying the image at the time of the inversion.

  The imaging apparatus according to claim 3, in the imaging apparatus according to claim 1, wherein the limitation of display of the display unit in the control unit displays an image when the lens unit is moved in the first direction. It is characterized by continuing.

  According to a fourth aspect of the present invention, in the imaging device according to the first aspect, the limitation of display on the display unit in the control unit is to prohibit display of an image on the display unit.

  In order to achieve the above object, an imaging apparatus according to claim 5 is an imaging device that receives light from a subject through a lens unit and outputs a signal, and a lens movement that can move the lens unit in an optical axis direction. Means, adjusting means for adjusting the focus based on a signal output from the imaging means as the lens unit moves, display means for displaying an image based on the signal output from the imaging means, and the lens When the unit is moved in the first direction, the lens moving unit is controlled to move the lens unit at the first speed, and the lens unit is moved from the first direction to the second direction. When the lens unit is moved to a position where the lens unit is stopped after being reversed, the lens unit is moved at a second speed higher than the first speed. And having a control means for controlling's mobile unit.

  In order to achieve the above object, the control method according to claim 6 includes an imaging unit that receives light from a subject through a lens unit and outputs a signal, and a lens movement that can move the lens unit in an optical axis direction. An image pickup device including: a control unit that adjusts a focal point based on a signal output from the image pickup unit as the lens unit moves; and a display unit that displays an image based on the signal output from the image pickup unit. In the apparatus control method, when the lens unit is moved in the first direction, display is performed on the display unit, and the lens unit is reversed from the first direction to the second direction. When the lens unit is later moved and stopped, control is performed so as to limit the display of the display means.

  In order to achieve the above object, the control method according to claim 7 includes an imaging unit that receives light from a subject through a lens unit and outputs a signal, and a lens movement that can move the lens unit in an optical axis direction. An image pickup device including: a control unit that adjusts a focal point based on a signal output from the image pickup unit as the lens unit moves; and a display unit that displays an image based on the signal output from the image pickup unit. When the lens unit is moved in the first direction, the lens unit is controlled to move the lens unit at a first speed, and the lens unit is moved to the first direction. When the lens unit is moved from the first direction to the second direction and then moved to a position where the lens unit is stopped, the lens unit is moved at a second speed higher than the first speed. And controlling the lens moving means to move the's unit.

  In order to achieve the above object, the program according to claim 8 includes: an imaging unit that receives light from a subject via a lens unit and outputs a signal; and a lens moving unit that can move the lens unit in an optical axis direction. And an adjustment unit that adjusts the focus based on a signal output from the imaging unit as the lens unit moves, and a display unit that displays an image based on the signal output from the imaging unit. When the lens unit is moved in the first direction, the control method performs display on the display means, and the lens unit is moved from the first direction. When the lens unit is moved and stopped after being reversed in the second direction, the display of the display means is limited.

  In order to achieve the above object, the program according to claim 9 includes an imaging unit that receives light from a subject via a lens unit and outputs a signal, and a lens moving unit that can move the lens unit in an optical axis direction. And an adjustment unit that adjusts the focus based on a signal output from the imaging unit as the lens unit moves, and a display unit that displays an image based on the signal output from the imaging unit. When the lens unit is moved in the first direction, the control method controls the lens unit to move the lens unit at a first speed. When the lens unit is moved from the first direction to the second direction and then moved to a position where the lens unit is stopped, And controlling the lens moving means to move said lens unit at a faster than the first speed the second speed.

  According to the present invention, since the image fluctuation is not displayed on the display means, the user is not discomforted.

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

  The imaging device according to the present embodiment is applied to a digital camera.

  FIG. 1 is a block diagram showing an electrical configuration of a digital camera which is an imaging apparatus according to an embodiment of the present invention.

  The digital camera 1 has a CPU 11 that controls the operation of the entire camera, and a signal processing circuit 12 is connected to the CPU 11. An image sensor 13 such as a CCD, a microphone 110 for inputting sound, and an image display device 14 such as an LCD (transmissive liquid crystal display) are connected to the signal processing circuit 12. The signal processing circuit 12 is connected to a signal output terminal 15 for outputting images and sounds to an external device, a speaker 16 for outputting sounds, and a memory 18.

  In the image sensor 13, the image formed by the lens unit 17 is photoelectrically converted and output as a video signal, and the signal processing circuit 12 performs an amplifier, A / D conversion, and γ processing on the output video signal. Various processes such as compression, D / A conversion, and the like are performed. Further, the microphone 110 converts the sound into an electric signal and outputs it to the signal processing circuit 12. The signal processed by the signal processing circuit 12 is input to the LCD 14 and the speaker 16 as an image / audio output for image display and sound reproduction, and from the signal output terminal 15 to a monitor or the like outside the digital camera. Output to the device.

  The CPU 11 is connected with an operation unit 118, a communication terminal 111, a power supply control unit 112, and a strobe 117, and various circuits of the lens unit 17 (an AF reset circuit 113, an AF motor 114, an aperture drive circuit 115, And a shutter driving circuit 116) and the like are connected.

  The operation unit 118 includes operation switches for operating the digital camera such as various operation buttons and a release button. The power control unit 112 includes a battery that supplies power to the entire digital camera, a DC / DC converter that generates a voltage to be supplied to each location, a control circuit that controls the voltage and current supplied to each location, and a battery check For example, a battery check circuit that performs voltage measurement.

  When shooting a moving image, the video signal output from the image sensor 13 is signal-processed by the signal processing circuit 12, and the signal processed signal is subjected to automatic exposure (AE) to determine the exposure amount. The driving circuit 115 is moved to determine the aperture value.

  When shooting a still image, a release button (not shown) included in the operation unit 118 is pressed to first activate the AF reset circuit 113 and the AF motor 114 to focus the image through the lens unit 17. Control to fit. Then, automatic exposure is performed from the output of the image sensor 13, the aperture value and shutter speed at which an appropriate exposure amount is obtained are determined, and the aperture is controlled so that the aperture drive circuit 115 is driven to obtain an appropriate exposure amount.

  Next, the image pickup device 13 is reset, charge accumulation is started by photoelectric conversion, and the shutter driving circuit 116 performs an operation of closing the shutter so that the shutter speed determined by the automatic exposure is obtained. If the exposure amount is insufficient, the strobe 117 is caused to emit light within the time when the shutter is open from the start of charge accumulation. The captured video signal is processed by the signal processing circuit 12, and the processed still image data is buffered in the memory 18 and recorded in a recording unit 19 such as an exchangeable memory medium.

  On the other hand, when the screen on the LCD 14 is freeze-displayed, the video signal is similarly processed by the signal processing circuit 12 and the still image data is buffered in the memory 18 and the buffered still image data is continuously reproduced. . When the screen on the LCD 14 is displayed as a through display, the data processed by the signal processing circuit 12 is continuously reproduced as it is. Thereby, the display image on the screen on the LCD 14 becomes a real-time through display image.

  2 and 3 are exploded perspective views of a part of the lens barrel of the digital camera 1.

  In the figure, reference numeral 200 denotes a lens barrel provided in the digital camera 1 of FIG. 1, and 201 denotes a CCD holder unit. The CCD holder unit 201 is a frame that holds an optical and imaging unit such as a CCD or a low-pass filter, and includes a linear key 201a and a barrier cam unit 201b that are integrated. Reference numeral 202 denotes a fixed barrel made of a non-conductive member, and 204 denotes a drive ring made of a conductive member. The fixed barrel 202 restricts other movements while making the drive ring 204 rotatable in the rotation direction. Reference numeral 205 denotes a one-sided spring made of a metal leaf spring.

  The drive ring 204 is sandwiched between the CCD holder unit 201 and the fixed barrel 202, and the drive ring 204 is shifted from the fixed barrel 202 toward the CCD holder unit 201 by the one-sided spring 205, so that the position of the drive ring 204 in the optical axis direction is adjusted. Fix it. The drive ring 204 and the biasing spring 205 are in direct contact and are electrically connected to the same potential.

  A barrier unit 206 is configured to protect the lens when the lens barrel is retracted by opening and closing two barrier blades.

  Reference numeral 207 denotes a lens whole group unit (corresponding to the lens unit 17 in FIG. 1), which holds the whole lens group and incorporates a diaphragm and a shutter inside. Drive the aperture and shutter. In the lens barrel 200, the groove in the lens all-group unit 207 and the straight key 201a are fitted, so that the lens all-group unit 207 can move back and forth in the optical axis direction.

  4 is a front view of the lens barrel 200 of the digital camera 1, and FIG. 5 is a cross-sectional view taken along line A-A 'in FIG.

  The lens all group unit 207 is divided into a lens (1) group frame 207a and a lens (2) group frame 207b, and these two are fixed by direct screwing, both of which are conductive carbon-containing mold members. It consists of For this reason, the lens (1) group frame 207a and the lens (2) group frame 207b are electrically connected at the same potential.

  Between the lens (1) group frame 207a and the lens (2) group frame 207b, two shutter blades 222a and 222b, a fixed opening diaphragm 223, and a small diaphragm blade 224 are incorporated. The small aperture blade 224 moves while rubbing the lens (1) group frame 207a on one side and the fixed aperture stop 223 on the other surface, and the two shutter vanes 222a and 222b are rubbing with each other between the shutter vanes, and One side of the shutter blade 222a is driven while rubbing against the fixed open aperture 223 and one side of the shutter blade 222b is rubbing against the lens (2) group frame 207b.

  As a material of the blades used for the shutter and the diaphragm, a conductive plate material is generally used for preventing static electricity due to friction, and a conductive material is also used in this embodiment. For this reason, static electricity generated by friction during driving of the aperture and the shutter is because the blades used for the aperture and the shutter are in contact with the lens (1) group frame 207a and the lens (2) group frame 207b, respectively, as described above. The entire lens group unit 207 escapes.

  In FIG. 4, reference numeral 225 denotes a barrier cap that is a metal member on the front surface of the lens barrel 200. When static electricity is conducted from the outside to the lens barrel 200, the static electricity is first conducted to the barrier cap 225, and the lens (2 ) Escape to the entire lens group unit 207 through the contact portion with the group frame 207b.

  3, 208 is a reduction gear group, and in FIG. 2, 214 is an AF motor comprising a stepping motor (corresponding to the AF motor 114 in FIG. 1). The rotational speed of the AF motor 214 is reduced by the reduction gear group 208 to increase the driving force (torque) of the AF motor 214, and the driving force is transmitted to a gear provided outside the driving ring 204. Rotate. Inside the drive ring 204, a cam groove and a helicoid concave are provided, and combined with a cam pin and a helicoid convex formed in the entire lens group unit 207. The drive ring 204 is made of a conductive member, and is electrically connected to the same potential as the lens all-group unit 207 through the cam pins of the lens all-group unit 207. The cam groove is rotated by the rotation of the drive ring 204, and the entire lens group unit 207 moves without rotating along the optical axis direction by the action of the cam and the straight key 201a.

  In order to make the movement of the lens all-group unit 207 due to the rotation of the drive ring 204 in the lens barrel 200 a smooth operation, there is a slight play (play) between the members that operate when the lens all-group unit 207 moves. Is provided. For this reason, the lens all-group unit 207 is slightly rotated and shifted by a backlash between the groove of the straight key 201a and the lens all-group unit 207 and the backlash between the drive ring 204 and the fixed lens barrel 202. (Movement in a direction perpendicular to the optical axis direction) occurs, which may cause the lens to fall or change the position of the optical axis, which may affect the image. Further, when the rotation direction of the drive ring 204 is reversed, each member moves in the rotation direction of the backlash drive ring 204 and the direction in which the backlash is displaced is changed, so that the lens is tilted or shifted, and the image is shaken. Will occur.

  A minute gap is provided so as not to mesh with the helicoid irregularities. This gap is set so that the helicoid unevenness is effective only when the drive ring 204 is deformed due to an external force applied such as an impact. This prevents the cam pins and cam grooves from being damaged by deformation such as deformation, breakage and cracking.

  From the above, static electricity generated by the diaphragm and shutter in the entire lens group unit 207 and static electricity conducted from the outside to the tip of the barrel 200 can be transmitted to the biasing spring 205 at the same potential. Further, a contact piece 205a is provided integrally with the biasing spring 205, and when the lens barrel 200 is attached to the digital camera 1, a ground as shown in FIGS. By disposing the substrate 221 and conducting with the contact piece 205a, static electricity can be released from the contact piece 205a onto the ground substrate 221. Therefore, when assembling the lens barrel 200, there is no trouble of wiring the lead wires, and the assembly becomes easy. The conductive portion of the ground substrate 221 with the contact portion 205 a is connected to the ground of the digital camera 1.

  The lens barrel 200 uses a conductive carbon-containing mold member only for the drive ring 204 and the two lens group frames 207a and 207b, and is connected to the ground by one leaf spring (one-sided spring 205). Therefore, it is not necessary to use a carbon material for the CCD holder unit 201 and the fixed lens barrel 202, and the cost can be reduced.

  6 and 7 are diagrams for explaining the operation of the barrier unit 206 of the lens barrel 200. FIG. 6 shows the barrier open state, and FIG. 7 shows the barrier closed state.

  In the figure, 41 is a barrier drive ring which is a member for driving the barrier unit 206, 42 is a barrier blade (1), and 43 is a barrier blade (2). 44 is an opening spring for applying a load to the barrier drive ring 41 in the opening direction, and 45 is a closing spring. The closing spring 45 is a hook-like spring and is locked to a protrusion 41a formed on the barrier drive ring 41. The force of the closing spring 45 urges the barrier blade (1) 42 in the closing direction. It is tidy up. The barrier blade (1) 42 and the barrier blade (2) 43 are engaged with each other by gears formed on the respective rotation shafts. When the barrier blade (1) 42 rotates, the barrier blade (2) 43 rotates in the opposite direction. It is designed to rotate.

  In the open state shown in FIG. 6, when the barrier drive ring 41 is rotated clockwise by the opening spring 44, the barrier blade (1) 42 is pushed by the protrusion 41a and rotates counterclockwise. As a result, the barrier blade (2) 43 is also rotated in the opposite clockwise direction, and the barrier is opened.

  Next, a case where the barrier is closed will be described. When the barrier drive ring 41 in the barrier unit 206 is pressed against the cam surface of the barrier cam portion 201 b, the barrier drive ring 41 rotates counterclockwise against the opening spring 44. At this time, since the protrusion 41a is lowered by the rotation, the barrier blade (1) 42 is simultaneously rotated clockwise by the action of the closing spring 45. The barrier blade (2) 43 also rotates counterclockwise due to the meshing of the gear and stops when the two blades 42, 43 are joined together (FIG. 7). The barrier drive ring 41 can rotate up to the state shown in FIG. 7, and the protrusion 41a further rotates and opens the closing spring 45 even when the barrier blade (1) 42 stops, thereby further increasing the barrier closing force. Charge.

  As described above, when the barrier unit 206 is coupled to the entire lens group unit 207 and integrally moves back and forth in the optical axis direction, the barrier drive ring 41 in the barrier unit 206 hits the cam surface of the barrier cam portion 201b. The barrier driving ring 41 is rotated by the spring force of the opening spring 44, and the two barrier blades 42 and 43 are opened and closed by the rotation and the closing spring 45.

  FIG. 8 is a diagram showing the relationship of the barrier state, the focus lens reset timing, and the extended state with respect to the rotation angle of the drive ring 204 in the lens barrel 200.

  The horizontal axis in the figure is the rotation angle of the drive ring 204, and the focus lens is extended and retracted by the rotation of the drive ring 204. A line 321 in the figure represents the amount of extension of the focus lens corresponding to the rotation angle of the drive ring 204. The line 322 indicates the state of the barrier at this time, and the line 323 indicates the state of the reset signal (PI signal).

  In the figure, reference numerals 300 and 311 denote a sinking end abutment and a close-up abutment, respectively, so that when the stopper of the drive ring 204 abuts mechanically, the rotation of the drive ring 204 is stopped and the focus lens does not move too much. It has become.

  When the AF motor 114 starts to rotate from the retracted position 301, the focus lens stops until the rotation angle of the drive ring 204 reaches a certain angle indicated by the position 302, and starts to extend from the position 302 as a boundary. The reset signal 323 switches from “L” level to “H” level at a position 303 immediately after the start of feeding.

  Here, a mechanism for switching the reset signal 323 will be described with reference to FIGS. 9A, 9B, and 9C. FIGS. 9A, 9 </ b> B, and 9 </ b> C are diagrams illustrating the relationship between the drive ring 204 and the reset member (PI) 61. The state of the drive ring 204 and the reset member 61 corresponding to the sink position 301 in FIG. 8 is shown in FIG. 9A, and the state corresponding to the barrier open position 305 in FIG. 8 is shown in FIG. A state corresponding to the closest end position 310 of FIG. 8 is shown in FIG. In the figure, reference numeral 204 a denotes a partition formed integrally with the drive ring 204, and an LED and its light receiving sensor are arranged in the reset member 61. The reset member 61 is configured to output an “H” level when the partition 204a blocks light emission of the LED, and outputs an “L” level otherwise.

  As described above, when the reset signal 323 switches to the “H” level at the position 303 and then the focus lens is further extended, the barrier unit 206 opens the barrier from the barrier closed position 304 by the action of the barrier cam portion 201b. The barrier is gradually opened to the position 305 at the phase where the drive ring 204 rotates. The barrier is completely opened at the barrier open position 305, and the barrier drive ring 41 is detached from the cam surface of the barrier cam 201b with the position 305 as a boundary.

  Similarly, when the drive ring 204 rotates in the reverse direction, the barrier cam 201b and the barrier drive ring 41 start to come into contact with each other from the barrier opening position 305, the barrier drive ring 41 rotates to start charging the opening spring 44, and the barrier drive ring 41 The barrier unit 206 gradually closes as it moves from the barrier open position 305 toward the barrier close position 304. Since the amount of charge of the opening spring 44 changes in the section from 304 to 305, the torque required for the rotation of the drive ring 204 changes in this section regardless of the direction of movement. The section where the torque change is large is in the section where the reset signal 323 is at the “H” level. Further, on the feeding side from the barrier opening position 305, the spring force of the opening spring 44 does not affect the rotation of the drive ring 204.

  When the driving ring 204 is further rotated in the direction in which the focus lens is extended from the position 305 where the barrier is opened, the partition 204a does not move from the phase of the position 306 and does not block the reset member 61. Therefore, the reset signal 323 is “L”. Switch to level. This position 306 is set as an AF reset position.

  Further, the phase of the position 307 where the drive lens 204 is rotated and the focus lens is extended is set as the AF scan start point. The focus lens is stopped at this position 307 when the power is turned on or after shooting. There is a focus position at infinity at a position 308 where the drive ring 204 is slightly rotated from there and the focus lens is extended. Further, the extended position 309 is set as a fixed point position, and the fixed point position 309 is a position determined by the F number and the minimum circle of confusion so that the focus is adjusted from infinity to a short distance as long as possible at the time of pan focus shooting. When the in-focus position cannot be detected by pan-focus imaging or AF, imaging is performed at the fixed point position 309. When the focus lens is further extended, the focus adjustment gradually becomes closer and reaches the closest end position 310.

  Next, a sequence when moving the lens barrel 200 will be described. FIG. 10 is a drive sequence diagram of the lens barrel 200 when the power is turned on when it is determined that the remaining battery level is sufficient, and FIG. 11 is when the power is turned on when it is determined that the remaining battery level is low. FIG. 6 is a drive sequence diagram of the lens barrel 200 of FIG.

  When the power is turned on, the battery check circuit in the power supply control unit 112 checks the voltage of the battery, and if it is equal to or greater than the predetermined threshold, it is determined that the remaining amount of the battery is sufficient and executes the sequence of FIG. If it is below the threshold value, it is determined that the remaining amount is small, and the sequence of FIG. 11 is executed.

  When the remaining battery level is sufficient (sequence in FIG. 10), the voltage supplied to the AF motor 114 including the stepping motor (AF motor 214) is set to a high value of 3.0V. The frequency of the pulses supplied to the AF motor 114 is determined by the interrupt cycle that can be used, and the interrupt is set to 300 μs.

  Then, as shown in FIG. 10, first, the AF motor 114 is rotated by 8 pulses from the sinking position 301 at the driving frequency 883PPS, and from the next pulse, the driving frequency is changed to 1111PPS and rotated by 8 pulses. Further, the drive frequency is changed to 1667 PPS and the rotation drive is continued. Since a stepping motor is used for the AF motor 114, the rotational speed can be increased to a speed that does not rotate with the pull-in torque by controlling the acceleration stepwise in this way. In this case, since the torque is lowered by increasing the driving frequency of the stepping motor, the torque is increased by increasing the voltage supplied to the stepping motor to 3.0 V in order to compensate for this.

  The driving ring 204 is rotated by the rotation of the AF motor 114 and the focus lens is extended, and the PI determination sequence (position 901 after the position 303 where the reset signal (PI) 323 switches from the “L” level to the “H” level) ( In order to enter the reset signal determination process), the speed is reduced to the frequency 883PPS, which is the initial speed. At this point, the battery check is performed again. If it is determined that the voltage falls below the threshold and the remaining amount is low, the interrupt frequency is switched from here and the sequence shown in FIG. 11 is entered. When the voltage is sufficient, the motor is accelerated again in two steps from 883 PPS to 1111 PPS in the same manner, and then the AF motor 114 is rotated at 1667 PPS. Then, it is driven to the AF reset position 306, and after the reset, it is decelerated by two steps, and is driven every 11 pulses by 1111PPS and 883PPS.

  Thereafter, the interrupt frequency is switched to 800 μs and the drive voltage is switched to 2.7V. After driving the AF motor 114 for 4 pulses at a driving speed of 625 PPS determined by an interrupt frequency of 800 μs, the AF motor 114 is driven to 4 pulses before the scan start point 307 at 1250 PPS, and after decelerating to 625 PPS, the scan start point 307 Stop at.

  The AF reset position 306 is moved by 1667 PPS even if the AF motor 114 steps out (a phenomenon in which the motor does not rotate even if a pulse is sent) and the pulse count and the lens position shift. This is because the pulse count can be corrected in accordance with the lens position in order to reset at the position 306. Further, since a force for releasing the charge of the barrier opening spring 44 is applied up to the barrier opening position 305, a margin is generated in the torque and the driving can be performed at a high speed. The positions 305 and 306 are as close as possible. After the reset, the focus lens position is not allowed to be misaligned. Therefore, the AF motor 114 is driven at a speed lower than the speed up to the AF reset position 306 in order to move at 1250 PPS with sufficient torque.

  Further, when the voltage is equal to or lower than the threshold value in the battery check, the driving sequence as shown in FIG. 11 is performed.

  As can be seen from a comparison with FIG. 10, the drive sequence shown in FIG. 11 is different from the drive sequence shown in FIG. 10 in terms of the voltage applied to the AF motor 114 and the interrupt frequency until the vehicle is decelerated after the AF reset position 306 from the sink position 301. , And the drive frequency and the number of acceleration / deceleration stages are changed. The normal voltage of 2.7 V is applied and the interrupt frequency is set to 375 μs. First, the AF motor 114 is driven by 8 pulses at 889 PPS determined by the interrupt frequency, and then driven by 1333 PPS. Then, PI determination is performed at the same position 901 as in FIG.

  The subsequent operation is the same as when the battery is insufficient at the time of PI determination in FIG. That is, after the AF motor 114 is driven by 889 PPS for 8 pulses, it is driven by 1333 PPS until the AF reset position 306, and after the reset, it is decelerated to 889 PPS for 8 pulses, and then the interrupt frequency is set to 800 μs. 114 is driven by 625 PPS for 4 pulses and then driven by 1250 PPS. In this case as well, the voltage is lowered, but the lens frequency can be corrected up to the AF reset position 306, and the load is reduced by the spring charging force. 1333PPS used up to 306 is set to be faster than 1250PPS used after reset.

  As described above, regarding the driving sequence of the lens barrel 200 when the power is turned on, the AF driving speed is increased faster than the normal driving frequency used after AF reset, regardless of whether the remaining battery level is sufficient or low. Since the motor 114 is moved, the lens can be extended quickly and the activation time can be shortened. The speed can be increased in this way because the load applied to the AF motor 114 is lightened by the spring force of the opening spring 44 up to the barrier open position 305, and there is a margin in torque, and the normal low speed after resetting. This is because even before the resetting, the lens can be out of step and corrected at the time of reset even at a speed that may cause the lens position to go wrong.

  After AF reset, by counting the number of pulses from which AF motor 114 is driven with reference to this AF reset position 306, the focus lens is positioned at the position corresponding to the scan start point and each subject distance. Can be paid out.

  In addition, when the battery check has a sufficient remaining capacity, the AF motor 114 is driven at a high speed by performing multi-stage acceleration control as compared with the case where the remaining amount is low, so that the focus lens can be extended more quickly. The start-up time from when the lens is retracted until the camera is turned on and can be photographed becomes faster.

  Next, a driving sequence of the lens barrel 200 when the power is turned off will be described. FIG. 12 is a drive sequence diagram of the lens barrel 200 when the power is off.

  The position where the focus lens is stopped after the power is turned on or after shooting is always at the scan start point 307. Therefore, as shown in FIG. 12, the power-off sequence starts from a scan start point 307, and the AF motor 114 is moved into the focus lens for 8 pulses at a normal interrupt frequency of 800 μs, a voltage of 2.7 V, and a drive frequency of 625 PPS. After driving in the direction, accelerate to 1250PPS. Then, the AF motor 114 is decelerated to 625 PPS at a position 902 immediately before the barrier opening position 305 at which the barrier starts to close. The deceleration position 902 is between the barrier opening position 305 and the AF reset position 306. On the retraction side from the barrier opening position 305, a strong driving torque is required to charge the opening spring 44, and the AF motor 114 is moved at this driving speed until it stops at the sink position 301 while being decelerated to 625PPS. The stepping motor at low speed has a strong torque and is difficult to step out without changing the voltage.

  After passing the barrier closing position 304, the closing spring 45 is charged, and the load of the AF motor 114 becomes higher as it approaches the sinking position 301. For this reason, since there is a high possibility of step-out near the sinking edge, a reset position 303 is provided near the sinking edge. After the sinking position reset is performed at the position 303, the position where the AF motor 114 is driven for a predetermined pulse from that position is driven as the sinking position 301.

  Since the rotational speed of the AF motor 114 is reduced by using many gears, a back-and-forth difference due to the rotational direction of the motor occurs in the movement amount of the lens due to gear backlash. For this reason, in order to reduce the time for the next start-up without stopping the AF motor 114 as it is at the sink position 301, the number of pulses necessary for removing this round-trip difference is given to the AF motor 114. Reverse to stop.

  At the time of shooting, since many interrupts are used for shooting functions and there is a torque margin as described above, only the interrupt frequency 800 μs is used, the driving speed of the AF motor 114 is 625 PPS and 1250 PPS, and the voltage is 2 Used at 7V. At the time of shooting standby, the focus lens is always stopped at the scan start point 307. AF scan starts from here.

  Here, the movement of each member due to the above-described play (play) will be specifically described. FIG. 15 is a diagram for explaining the movement of the lens due to play between the straight key 1502 for guiding and moving the lens in the optical axis direction and the lens barrel 1501 for holding the lens, and FIG. FIG. 15B is a diagram for explaining movement due to backlash when there are three 1502, and FIG. 15B is a diagram for explaining movement due to backlash when there is one straight-ahead key 1502. Similar to the rectilinear key 201a, the rectilinear key 1502 is fitted into a groove 1503 formed in the lens barrel 1501 to restrict the movement of the lens barrel 1501 in the optical axis direction.

  As shown in FIG. 15A, when a cam (not shown) rotates in the direction of the arrow, there are slight backlashes between the three grooves 1503 of the straight key 1502 and the lens barrel 1501, so that there are three contact points. At 1502a, the straight key 1502 contacts the groove 1503 of the lens barrel 1501. As described above, the lens barrel 1501 and the linear key 1502 come into contact with each other at the three contact points 1502a, so that the direction of the force applied to the lens barrel 1501 is balanced and the lens barrel 1501 is slightly rotated. The position hardly moves. However, when there is only one rectilinear key 1502 as shown in FIG. 15B, the lens barrel 1501 rotates about the rectilinear key 1502 in the rotation direction (the direction of the arrow in FIG. 15B), The amount of movement in the rotational direction of the lens barrel 1501 is larger than that in the case where there are three linear keys 1502 (FIG. 15A), and the degree of freedom of movement of the lens barrel 1501 is increased. As a result, the optical axis shifts. In addition, the cam pin position to which the rotational force of the cam is applied is often located near the base of the lens barrel 1501, and when there is one linear key 1502, the contact point between the linear key 1502 and the groove 1503 is supported by this rotational force. As described above, there are times when the front and rear ends of the lens barrel 1501 move differently.

  Therefore, in order to suppress image shake, it is better to form as many linear keys as possible. If possible, it is necessary to form at least two linear keys so that the lens barrel does not shift. . That is, even if an attempt is made to reduce the size of the camera by reducing the number of straight-ahead keys, image distortion may occur due to a lens barrel shift or the like, which may cause discomfort to the user. Therefore, in the present embodiment, as described later, the user is prevented from feeling uncomfortable.

  FIG. 13 is a conceptual diagram illustrating a driving sequence of the lens barrel 200 during AF scanning, and FIG. 14 is a flowchart of lens barrel driving processing during AF scanning. Note that the following lens barrel driving process can be realized by storing a program according to this sequence in, for example, a storage device in the digital camera 1 and executing it by the CPU 11.

  As shown in FIGS. 13 and 14, AF scan is started at the scan start point 307 (step S1401). During the AF scan, the focus lens is driven at a low speed of 625 PPS, and the display screen of the LCD 14 is displayed as a through display (step S1401). S1402). In this AF scan, the high-frequency component of the image at each position is read while moving the focus lens, the amount of the high-frequency component is sampled as a focus evaluation value, and the peak is obtained. Therefore, since the focus lens moves while sampling an image from the scan start point 307 to the closest end position 310, or in the case of not being in the macro mode, it needs to move at a low speed. . In the present embodiment, scanning is performed from the start point 307 to the closest end position 310. However, the present invention is not limited to this. For example, the range from the start point 307 to the fixed point 309, or the subject distance 0 from the start point 307. It is also possible to scan within a predetermined stroke range, such as a range up to 0.5 m.

  Thereafter, the AF motor 114 is reversed at the closest end position 310, and the display screen is freeze-displayed accordingly, thereby restricting the through display (401 in FIG. 13) (step S1403). Then, the position 903 having the peak is set as a focal point, and the focus lens is moved toward the position. First, after the motor is reversed in step S1403, the AF motor 114 is driven with 4 pulses at 625 PPS and accelerated to 1250 PPS, and is reversed at a point exceeding a predetermined N pulse from the focal point 903 (see 402 in FIG. 13). . The predetermined N pulse is a value determined by the hysteresis amount of the focus lens, and takes the number of pulses with a slight margin in the hysteresis amount of the focus lens in consideration of variations during mass production. At this time, the AF motor 114 is decelerated and stopped at 625 PPS for the 4 pulses before reversing, starts driving again with 4 pulses 625 PPS after reversing (402 in FIG. 13), is accelerated to 1250 PPS, and the 4 pulses just before the stopping are 625 PPS. The motor is decelerated and stopped at the focal point 903 of the Nth pulse after the second inversion (step S1404) (see 403 in FIG. 13).

  At the time of the first inversion (step S1403), the display screen of the LCD 18 is set to the freeze display, and thereafter the freeze display is continued. After the AF motor 114 is stopped in the step S1404, the display is again returned to the through display. It is reproduced on the LCD 14 in real time (step S1405). Thereafter, the shutter is operated to perform a photographing operation (403 in FIG. 13) (step S1406).

  After photographing, freeze display is started again with the photographed image (step S1407). When the release button is released after shooting, the operation of the AF reset position 306 is started (S1408). Again, since the driving direction of the focus lens is reversed, the focus lens is driven with the freeze display. The focus lens drives the same 625 PPS for 4 pulses, then drives it in the retraction direction at 1250 PPS, reverses the AF motor 114 past the AF reset position 306 and before the barrier opening position 305 (404 in FIG. 13), and drives in the retraction direction. After resetting again (step S1409), the process returns to the scan start point 307 (405 in FIG. 13). At this time, the display screen is set to through display (step S1410).

  The display screen when switching from the through display to the freeze display in step S1403 may display an image frozen at the time of switching, or display an image at the scan start point. It may be. In addition, an image at or near the focal point 903 may be displayed. By not displaying an image through a lens that has fallen due to the reversal of the AF motor 114, it is possible to prevent an unexpected change in the frame image for the photographer (user).

  In the above description, it has been described that an image is displayed during freeze display. However, the present invention is not limited to this. For example, the display device may be darkened such as prohibiting display of an image. In addition, by restricting the through display on the LCD 14 at the time of inversion, it is possible to follow the subject to the user (photographer). For example, even at the previous timing, the lens collapses. There is a certain effect that the display of the angle of view variation due to the above is restricted and the user (photographer) is not uncomfortable.

  As described above, in this embodiment, since the image fluctuation is not displayed on the display means, the user is not uncomfortable. In addition, during AF scanning in which the focus lens moves at a low speed by driving the AF motor with 625PPS, the display screen is displayed as a through display, freeze display is made when the moving direction of the lens that is likely to cause image shake changes, and high speed is achieved at 1250PPS. Since the time for freeze display is shortened by moving the lens, the time for through display becomes longer than the freeze display in terms of time ratio. As a result, when shooting a moving subject, it is possible to follow the subject while looking at the screen of the LCD 14, and image fluctuation is not reflected on the screen, so that the user is not uncomfortable.

  Since the digital camera 1 has the straight key 201a reduced to one, image shake due to play (play) is likely to occur as described above. However, even if image shake occurs due to play, the image shake is displayed on the display screen. This will not cause discomfort to the user. Therefore, reducing the number of straight-ahead keys increases space efficiency and is advantageous for reducing the size of the camera.

  In the photographing region, since the focus lens is driven at a low driving frequency at a low speed compared to when the AF motor of 1250 PPS at the maximum is started, there is little possibility that the AF motor 114 will step out. Since the barrier driving area is not passed after the scan start point 307 during the AF operation, the driving torque required for the AF motor 114 is constant and low, and the motor 114 is less likely to step out. Even when a step-out has occurred, since the resetting is performed again, the lens position is corrected correctly in the next shooting, so that it is possible to avoid shooting with the lens shifted.

  The present invention is not limited to the apparatus of the above-described embodiment, and may be applied to a system constituted by a plurality of devices or an apparatus constituted by one device.

  Another object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the above-described embodiments to a system or apparatus, and the computer (or CPU or MPU) of the system or apparatus stores the storage medium. This can also be achieved by reading and executing the program code stored in.

  In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

  Examples of the storage medium for supplying the program code include a floppy (registered trademark) disk, a hard disk, a magneto-optical disk, a CD-ROM, a CD-R, a CD-RW, a DVD-ROM, a DVD-RAM, and a DVD-RW. DVD + RW, magnetic tape, nonvolatile memory card, ROM, etc. can be used. The program code may be downloaded via a network.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on the instruction of the program code Includes a case where part or all of the actual processing is performed and the functions of the above-described embodiments are realized by the processing.

  Furthermore, after the program code read from the storage medium is written to the memory provided in the function expansion board inserted in the computer or the function expansion unit connected to the computer, the program code is expanded based on the instruction of the next program code. This includes a case where a CPU or the like provided in the expansion board or expansion unit performs some or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

It is a block diagram which shows the structure of the digital camera which is an imaging device which concerns on embodiment of this invention. It is a disassembled perspective view of a part of lens barrel of the digital camera. It is a disassembled perspective view of a part of lens barrel of the digital camera. It is a front view of a lens barrel of a digital camera. FIG. 5 is a cross-sectional view taken along line A-A ′ of FIG. 4. It is a figure for demonstrating operation | movement of the barrier unit of a lens-barrel (barrier opening). It is a figure for demonstrating operation | movement of the barrier unit of a lens-barrel (barrier closing). It is a figure which shows the relationship of the state of a barrier, the reset timing of a lens, and the extended state with respect to the rotation angle of the drive ring in a lens barrel. It is a figure which shows the relationship between the drive ring in a lens-barrel, and a reset member (PI). It is a lens barrel drive sequence diagram at the time of power-on when it is determined that the remaining amount of the battery is sufficient. It is a lens barrel drive sequence diagram at the time of power-on when it is determined that the remaining amount of the battery is low. It is a lens barrel drive sequence diagram when the power is off. It is a conceptual diagram which shows the lens-barrel drive sequence at the time of AF scan. It is a flowchart of a lens barrel driving process at the time of AF scanning. FIGS. 15A and 15B are diagrams for explaining the movement of the lens due to the play of the straight key. FIG. 15A is a view for explaining the movement of the lens when there are three straight keys, and FIG. It is a figure for demonstrating the motion by looseness in the case of one key.

Explanation of symbols

1 Digital camera 11 CPU
12 Signal Processing Device 13 Image Sensor 14 LCD
17 Lens part 18 Memory 41 Barrier drive ring 42 Barrier blade (1)
43 barrier blades (2)
44 Opening spring 45 Closing spring 61 Reset member 113 AF reset circuit 114, 214 AF motor 118 Operation unit 200 Lens barrel 201 CCD holder unit 201a Linear key 201b Barrier cam unit 202 Fixed lens barrel 203 Lens barrel flexible 204 Drive ring 204a Screen unit 205 Piece Bending spring 205a Contact piece 206 Barrier unit 207 Lens whole group unit

Claims (9)

Imaging means for receiving light from the subject via the lens unit and outputting a signal;
Lens moving means capable of moving the lens unit in the optical axis direction;
Adjusting means for adjusting the focal point based on a signal output from the imaging means as the lens unit moves;
Display means for displaying an image based on a signal output from the imaging means;
When the lens unit is moved in the first direction, display is performed on the display means, the lens unit is reversed from the first direction to the second direction, and then the lens unit is moved. An image pickup apparatus comprising: control means for controlling to limit display of the display means when stopping.   The imaging apparatus according to claim 1, wherein the display unit has a display limitation in the control unit that the image at the time of the inversion is continuously displayed.   The imaging apparatus according to claim 1, wherein the display unit restricts the display of the control unit to continue displaying an image when the lens unit is moved in the first direction.   2. The imaging apparatus according to claim 1, wherein the display unit restricts display of the control unit to prohibit display of an image on the display unit. Imaging means for receiving light from the subject via the lens unit and outputting a signal;
Lens moving means capable of moving the lens unit in the optical axis direction;
Adjusting means for adjusting the focal point based on a signal output from the imaging means as the lens unit moves;
Display means for displaying an image based on a signal output from the imaging means;
When the lens unit is moved in the first direction, the lens moving unit is controlled to move the lens unit at a first speed, and the lens unit is moved from the first direction to the second direction. Control means for controlling the lens moving means to move the lens unit at a second speed higher than the first speed when the lens unit is moved to a position to be stopped after being reversed in the direction. An imaging apparatus comprising: Imaging means for receiving light from a subject via a lens unit and outputting a signal, lens moving means for moving the lens unit in the optical axis direction, and output from the imaging means as the lens unit moves An imaging apparatus control method comprising: an adjustment unit that adjusts a focal point based on a signal; and a display unit that displays an image based on a signal output from the imaging unit.
When the lens unit is moved in the first direction, display is performed on the display means, the lens unit is reversed from the first direction to the second direction, and then the lens unit is moved. A control method characterized by controlling to limit the display of the display means when stopping. Imaging means for receiving light from a subject via a lens unit and outputting a signal, lens moving means for moving the lens unit in the optical axis direction, and output from the imaging means as the lens unit moves An imaging apparatus control method comprising: an adjustment unit that adjusts a focal point based on a signal; and a display unit that displays an image based on a signal output from the imaging unit.
When the lens unit is moved in the first direction, the lens unit is controlled to move the lens unit at a first speed, and the lens unit is moved from the first direction to the second direction. The lens moving unit is controlled to move the lens unit at a second speed higher than the first speed when the lens unit is moved to a position where the lens unit is stopped after being reversed. Control method. Imaging means for receiving light from a subject via a lens unit and outputting a signal, lens moving means for moving the lens unit in the optical axis direction, and output from the imaging means as the lens unit moves A program for executing a control method for an imaging apparatus, comprising: an adjusting unit that adjusts a focus based on a signal; and a display unit that displays an image based on a signal output from the imaging unit,
In the control method, when the lens unit is moved in the first direction, display is performed on the display means, and the lens unit is reversed from the first direction to the second direction, and then the lens is moved. A program for restricting the display of the display means when the unit is moved and stopped. Imaging means for receiving light from a subject via a lens unit and outputting a signal, lens moving means for moving the lens unit in the optical axis direction, and output from the imaging means as the lens unit moves A program for executing a control method of an image pickup apparatus having an adjustment means for adjusting a focus based on a signal and a display means for displaying an image based on a signal output from the image pickup means,
In the control method, when the lens unit is moved in the first direction, the lens unit is controlled to move the lens unit at a first speed, and the lens unit is moved in the first direction. The lens moving means is controlled to move the lens unit at a second speed higher than the first speed when the lens unit is moved to a position where the lens unit is stopped after being reversed in the second direction. A program characterized by that.

Images