JP2010145887A - Camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that driving of a lens becomes intermittent driving of microdriving because it can not be controlled at a predetermined speed, that a feeling of strangeness is brought especially during shooting while viewing a display or shooting of motion pictures, that a delay is caused in driving itself and that it takes time for focusing because it once stops and then is driven again, when the lens not compatible with AF on the basis of output of imaging elements (hereinafter called TV-AF) is mounted, though a camera system which can perform TV-AF needs to control speed by the image plane moving speed for driving a lens for focusing. <P>SOLUTION: The camera updates driving instruction from driving control information and remaining pulses obtained on the basis of lens information at a timing when driving does not become intermittent so that the lens not compatible with TV-AF can be driven in a pseudo manner at a predetermined image plane moving speed. In this manner, a predetermined driving state can be created in a pseudo manner and the lens becomes compatible with TV-AF. A photographer does not get a feeling of strangeness and the delay in focusing can be prevented. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a camera system that performs autofocus control based on the output of an image sensor in a camera system having an image sensor that can capture still images and moving images.

  Conventionally, in a single-lens reflex camera capable of exchanging lenses, a phase difference detection type automatic focusing device (hereinafter referred to as AF) is used in many models as a focus detection unit. This phase difference detection type AF system generally operates as follows.

  In this phase difference detection method, a light beam incident from a lens is separated into two light beams, and each light beam is incident on two AF sensors forming a pair. Each AF sensor photoelectrically converts an image formed by each separated light beam. The relationship between the outputs from the two AF sensors, that is, the interval between the two images varies depending on the in-focus state, the front pin state, and the rear pin state, and the focus lens is moved so that this image interval becomes the in-focus interval. To focus.

  That is, since the relationship between the shift amount of the two images and the image plane movement amount, so-called defocus amount, is determined by the photographing optical system, the defocus amount is obtained from the shift amount. Then, the drive target position of the focus lens is obtained from the defocus amount, and the lens is moved toward the drive target position to obtain in-focus. Therefore, if the drive target position can be detected, there is an advantage that the time to focus can be shortened as compared with other methods by driving at high speed toward the position and stopping with high accuracy. The drive control method at this time will be described based on the control curve of FIG.

  Specifically, the maximum image plane moving speed is determined by the photometric result at the start of the control, and is selected from the second speed (A, B) in FIG. The focus lens drive amount is provided with position detection means for generating a pulse signal in accordance with the drive amount of the focus lens drive unit, and control based on the remaining pulses with respect to the target drive position is performed.

  When driving without knowing the drive target position when the drive command is issued (for the sake of explanation, the remaining pulse is the 800 pulse position as the initial drive value), the driving speed is accelerated to the driving speed determined by the photometric result (C (Dotted line part), then drive to trace A or B, defocus amount can be detected, and when remaining pulse is determined, drive along deceleration curve (D) according to remaining drive pulse and stop To do. Therefore, since driving is performed along the deceleration curve (D) when the defocus amount can be detected, for example, even when driving at B, the vehicle is switched to D like the E line, so the time until focusing can be shortened. . The reason for driving along the deceleration curve D is to ensure stopping accuracy, and the lens device is determined to an optimum value by the lens device, such as the mass of the focus lens group and the type of the drive unit of the focus lens group. Is stored in the storage means.

  On the other hand, if the pulse to the drive target position is 100 pulses, the vehicle is accelerated to the deceleration curve (D) and then decelerated based on the deceleration curve (D) without depending on the maximum speeds A and B described above, and at the target drive position. Quiesce.

  On the other hand, there are many digital single-lens reflex cameras with interchangeable lenses equipped with an image sensor, and those equipped with a live view mode that always captures the image sensor signal and displays it on the display means. A camera system has also been devised. In addition, a camera system corresponding to a contrast detection method that performs autofocus based on an output of an image sensor signal and a focus detection method called a hill-climbing method (hereinafter referred to as TV-AF) has been devised.

  Since this TV-AF is focused on the basis of a signal obtained from an actual image sensor, the focusing accuracy can be generally increased as compared with a phase difference detection method. However, since the range of the defocus amount that can be detected is narrower than that of the phase difference detection method and is not suitable for control using the same defocus amount as in the phase difference method, actual control is performed as follows.

  The imaging unit captures image light and extracts a high-frequency component of the output video signal. The maximum value of the extracted signal is stored, the focus lens is moved in a certain direction, and image light is taken in the same way to extract high frequency components. When the maximum value is larger than the stored value, it is determined that the moving direction of the focus lens is approaching the in-focus plane, the current value is stored again, and the focus lens is moved in the same direction. Moving. If the current maximum value is smaller than the previous value, it is determined that the moving direction of the focus lens is moving away from the in-focus plane, the current value is memorized again, and the focus lens is moved in the opposite direction. . In this way, extraction of high frequency components and comparison of the maximum values are performed, and the focus lens is moved so that the image plane is finally brought to the in-focus plane.

  At this time, the focus lens itself is driven without stopping, and its moving speed is high in the high frequency component near the in-focus position, so it is necessary to drive the lens slowly. When a lens device without a lens was attached, the high-speed drive and stop were repeated, resulting in an unsightly shooting screen.

  In Patent Document 1, in the case of moving image shooting, the moving target position is set a plurality of times within the vertical synchronization period at the time of moving image shooting so that the photographer does not feel uncomfortable even when moving at a predetermined low speed cannot be performed. By updating the predetermined number of times, the average speed within one vertical synchronization period is set to a substantially predetermined low speed drive.

Patent Document 2 has focusing means for both the phase difference detection method and the TV-AF, drives the focus lens toward the driving target in the phase difference detection method, and stops the TV-AF immediately before the target position. There has also been a proposal to improve accuracy by switching without switching.
JP-A-10-164417 JP 2004-109690 A

  However, in the system capable of focusing operation by the TV-AF as described above, the drive unit of the focus lens group of the mounted lens device is a drive unit corresponding to driving at a required speed (particularly in a low speed region). If there is no problem if the lens device to be mounted is a lens device that does not support TV-AF, low-speed driving cannot be performed, and there is no other way than to cope by performing minute amount driving intermittently. For this reason, the photographer feels uncomfortable with repeated driving and stopping, and in a lens apparatus using a so-called ultrasonic motor as a driving unit, in this driving control, the driving is temporarily stopped and then re-driven. There is a problem that the frequency needs to be swept again and the time until re-drive increases, resulting in an increase in time until focusing. In other driving units, once stopped, the driving starts from static friction, so that a delay occurs.

  In addition, as in Patent Document 1, the average speed is set to a substantially predetermined low speed drive by updating the drive within the vertical synchronization period at the time of moving image shooting a plurality of times. Since the speed is driven at a moving speed due to the feedback loop characteristic of the drive system, the stop state is also included. Accordingly, when re-driving is necessary, the time until re-driving occurs as described above, and it may be difficult to adjust the average speed.

  On the other hand, in Patent Document 2, the focusing means is changed midway from the phase difference detection method to TV-AF, and when driven based on TV-AF, low-speed driving is an indispensable condition. It was necessary to install the lens device.

  In view of this, the present invention sets the drive target position and the output timing of the drive command by the control based on the conventional drive target position even in a lens device that does not support the drive based on this output using the TV-AF as a focusing means. The purpose of this is to make it possible to perform focusing in the TV-AF by simulating driving in the speed range where TV-AF is possible without stopping the focus lens group.

In order to achieve the above object, a focus lens group movable on the optical axis for focus adjustment, a drive unit for driving the focus lens group, and a position detection unit for detecting the position of the focus lens group A lens apparatus having a photographing optical system,
An image sensor and a camera capable of performing a first focus control for detecting a focus state based on an output of the image sensor and controlling a drive speed of the focus lens group in a predetermined speed range toward a focus position. In a camera system composed of
When a lens device that does not support driving based on the first focus control and controls the focus lens group based on the driving target position is mounted on the camera, unique information of the lens device is displayed on the camera side. Based on the determination result, the driving of the focus lens group is stopped by the second focusing control in which the driving target position and the output timing of the driving command are changed instead of the first focusing control. It is possible to drive the camera at a low speed without causing the photographer to focus on the TV-AF without causing the photographer to feel uncomfortable.

  The position detection means detects the pulse signal generated by the movement of the focus lens group, the second focus control outputs a drive command based on the number of remaining pulses up to the drive target position, and outputs the drive command. Is updated before the previous drive target position, and the focus lens group can be driven without stopping by changing the next drive target position in accordance with the remaining drive pulses up to the previous drive target.

  Further, the driving target position and the output timing by the second focusing control are changed according to the specific information of the mounted lens device, the focal length, and the subject distance, so that the lens specific conditions are reflected in the driving conditions. be able to.

  Also, in the unlikely event that the focus lens group is stopped with a remaining drive pulse left due to an external factor or the like, it is re-driven based on the information at the time of stop, thereby preventing an inoperative state. If the focus lens group cannot be driven in the predetermined speed range with the drive command based on the second focus control, a warning display is displayed on the display means and intermittent drive with continuous minute drive is performed. The focusing operation can be continued.

  Further, by using an ultrasonic motor as the drive unit of the focus lens group, it is possible to secure a torque sufficient for driving.

  As described above, according to the present invention, even when a lens device that does not support the contrast detection method (TV-AF) based on the output of the image sensor is attached to the camera, the drive target position and the output timing of the drive command are changed. By doing so, it is possible to drive the focus lens group at a predetermined speed without stopping the driving, and pseudo speed control can be performed.

  Therefore, it is possible to provide a camera system that does not give a sense of incongruity to the photographer while improving focusing accuracy.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  FIG. 1 shows the configuration of a camera system according to the first embodiment of the present invention. In FIG. 1, reference numeral 100 denotes a digital camera, and reference numeral 200 denotes an interchangeable lens (lens device) that is attached to and detached from the camera 100. These digital cameras and interchangeable lenses constitute this camera system.

  The subject 300 passes through the optical systems 201 and 202, the focus lens group 203, and the diaphragm 204 in the interchangeable lens 200 and enters the camera 100. The interchangeable lens 200 in this embodiment is a single focus lens having a focal length of 200 mm and an open F number of 2.8, and a focus drive unit (configured by a motor and its drive circuit) 208 that drives the focus lens group 203. I have.

  Reference numeral 205 denotes an aperture driving circuit that controls the aperture diameter of the aperture 204 based on a signal from the lens CPU 207. Reference numeral 206 denotes an operation means, which enables setting of auto / manual switching of focusing, etc. by a manual operation switch. Reference numeral 207 denotes a lens CPU that exchanges information via the camera CPU 111, the lens communication circuit 211, and the camera communication circuit 102, and controls the entire lens.

  Reference numeral 209 denotes a focus lens position detection means, which is provided with a pulse generator at a portion that rotates as the motor of the focus drive unit 208 rotates, and detects the position by detecting a pulse signal from the pulse generator. Yes. In the present embodiment, this driving unit uses an ultrasonic motor. The lens CPU 207 counts the pulse signal from the focus lens position detection sensor 212 to detect the amount of rotation of the motor of the focus drive unit 208, that is, the amount of movement of the focus lens group 203, and sets the cycle of the pulse signal. By detecting this, the speed of the motor and focus lens group 203 can be detected.

  The focus driving unit 208 drives the focus lens group 203 in the optical axis direction in accordance with a signal from the lens CPU 207 and performs position control based on information from the focus lens position detection sensor 212.

  Reference numeral 210 denotes a storage circuit composed of a ROM or the like, a unique identification number (ID) of the interchangeable lens 200, focal length information, and a focus sensitivity that is a ratio of an image plane movement amount to a movement amount of the focus lens group 203, The deceleration curve etc. which are mentioned later are stored. Information stored in the storage circuit 210 can be read by the lens CPU 207 at any time.

  The light beam incident on the camera 100 from the interchangeable lens 200 passes through the prism 101 having a fixed half mirror and forms an image on the imaging surface of the image sensor 108. The image sensor 108 is composed of a photoelectric conversion element such as a CCD or CMOS sensor. In the prism 101, a part of the light beam (1/3 in this embodiment) is branched in the vertical direction and is incident on the pentaprism 103.

  A first focus detection unit 104 is disposed on the optical path branched in the pentaprism 103. The first focus detection unit 104 detects the focus adjustment state of the photographing optical system by a method called a phase difference detection method. In this embodiment, an F8 light beam is used, and this is divided into two, and an image formed by each is detected by a pair of sensors (not shown). A detection signal from this sensor is input to the camera CPU 111.

The light that has passed through the pentaprism 103 passes through the finder optical system 106 and is visually recognized by the photographer as an optical finder image. Amplified and input to the camera CPU 111 as a digital video signal. In the camera system of this embodiment, a moving image or a still image is formed using this video signal.

  The digitized video signal is also input to the AF processing circuit 109 separately from the transmission to the camera CPU 111 described above. The AF processing circuit 109 receives the input digital video signal, extracts high frequency components of image data for one screen through a high pass filter (HPF), etc., and performs arithmetic processing such as cumulative addition on this. Is done. Thereby, focusing control (AF control) can be performed as a second focus detection unit by a contrast detection method (TV-AF) in which an AF evaluation value corresponding to the contour component amount on the high frequency side is calculated. The AF evaluation value is input to the camera CPU 111 as indicating the focus adjustment state of the photographing optical system. Details of the AF control will be described later.

  A photometric unit 105 transmits photometric information to the camera CPU 111. A release switch 107 includes a two-stage switch. When the first stage is turned on, a SW1 signal for starting photometry, focus detection, and focusing operation is output. When the second stage is turned on, exposure recording by the image sensor 108 is performed. The SW2 signal to be started is output. These SW1 signal and SW2 signal are input to the camera CPU 111.

  The camera CPU 111 and the lens CPU 207 function as control means that controls AF control of the camera system. The camera CPU 111 communicates with the lens CPU 207, controls the display unit 112 such as an LCD, controls the input from the setting circuit 113 for setting various operation modes, checks the remaining capacity of the power source 110, and shares power. It is responsible for all control. The recording device 114 also controls to store the captured video signal in a medium (not shown), and various buffer memories and the like are included in the camera CPU 111 in this embodiment.

  As described above, this camera system is a system having two types of focus detection units, ie, a phase difference detection method and a TV-AF, and is configured to be appropriately selected by a photographer. For example, if you want to reduce the time to focus, use phase difference detection AF control. Conversely, if you want to achieve focus accuracy even if it takes time to focus, Use.

  Next, the AF control of this embodiment will be described with reference to FIGS. 2, 3, and 4. In the AF control by the phase difference detection method of the present embodiment, first, the focus detection unit 104 calculates a defocus amount, and based on the defocus amount and sensitivity information stored in the storage circuit 210. 2 is converted into a target drive amount (target drive pulse) for driving the focus lens group 203 to the in-focus position, and the focus lens group 203 is represented by a deceleration curve D in FIG. 2 based on the number of remaining drive pulses up to the target position. To drive. If the defocus amount cannot be detected, driving is performed at the image plane speed A or B based on the information of the photometry unit 105, and if the defocus amount can be detected, driving is performed along the D line.

  In focus control in TV-AF, the required image plane movement speed at the time of focus detection is the image plane movement speed that allows focus discrimination during the charge accumulation time of the image sensor. Usually, phase difference detection is performed. The speed is slower than that of the AF method.

  In the camera system of the present embodiment, the lowest target speed of the image plane moving speed in TV-AF is Gmm / S, and the focus cannot be determined unless it is within the range of G ± 2 mm / S (F).

  Therefore, in the conventional system, when a lens apparatus that only supports driving of the phase difference detection method is mounted, the driving information at the image plane moving speed is not stored in the storage means in the lens apparatus 200. Since the lens CPU does not support driving in this speed range, the only way to control focusing with the TV-AF is to repeatedly perform micro-driving / focus determination. For this reason, the photographer feels uncomfortable with intermittent driving, and in the example of the present embodiment using an ultrasonic motor, a re-sweep operation of the driving frequency is performed to drive the ultrasonic motor during re-driving. There was a problem that it took a long time.

  In the camera system according to the present embodiment, even when a lens device that can only drive the focus lens group based on the phase difference detection method that supports only the conventional A and B speed control is mounted. TV-AF without any sense of incongruity is possible.

  Specifically, the contents of the control will be described with reference to FIGS. FIG. 3 is a detailed view of a portion C in FIG.

  As described above, the minimum target drive speed in this camera system is Gmm / S, and it is necessary to drive within the range (F) of G ± 2 mm / S in the shaded area F in the figure. Therefore, when a lens device that does not store drive information for speed control in this area is mounted, the camera CPU 111 determines the specific information of the mounted lens, and determines that a non-corresponding lens is mounted. In this case, the driving is performed in a second focus control mode different from the normal TV-AF focus control.

  In FIG. 3, the shaded area F is between 3 and 12 remaining drive pulses when considering the deceleration curve of the phase difference detection method of the lens apparatus 200. That is, if the remaining drive pulses are continuously controlled between these 3 to 12 pulses, TV-AF is possible.

  Specifically, when driving in this drive speed range (F), the focus lens group starts to be driven as 12 pulses to the drive target position regardless of the actual drive target position. Then, control is performed to accelerate along the E line and then gradually decelerate along the deceleration curve D. Before the remaining pulse becomes 3 pulses, the target drive position is within 12 pulses in total in addition to the number of remaining pulses. The drive command is issued as follows. This is because the drive speed range (F) is exceeded when 12 pulses or more are reached. Similarly, by updating the drive command before the remaining pulses become 3 pulses, it becomes possible to drive at a pseudo minimum target drive speed.

  FIG. 4 is a diagram in which the horizontal axis represents the number of drive pulses and the vertical axis represents the image plane moving speed. As can be seen from this figure, the drive target position is updated before the previous drive target position by changing the drive command and its output timing, and the next pulse according to the remaining pulses up to the previous drive target position at that time The drive target position is changed. When updating at the position 3 pulses before, the drive target position is updated as 9 pulses, and when the remaining drive pulse is updated at 4 pulses, it is updated as the drive target position of 8 pulses. The driving speed can be set so as not to exceed the upper limit value of the predetermined speed.

  In this embodiment, the drive target position and the output timing of the drive command are changed in accordance with the focal length and subject distance obtained from the unique information of the lens device, and the lens device ID stored on the camera side is changed. Compared with the information, it is determined whether or not TV-AF and second focusing control are possible, and control is performed based on the result.

  FIG. 5 is a flowchart showing the second focus control in the focus control using the TV-AF of this embodiment, and mainly shows the control operation of the lens CPU 207 and the camera CPU 111. In this flowchart, the programs of the lens CPU 207 and the camera CPU 111 are integrally described for easy understanding of the explanation, but actually, they are configured by different programs.

  First, when the power is turned on by the setting means 103 in the camera-side electric circuit 100, power supply to the lens-side electric circuit 200 is started, and communication between the camera CPU 111 and the lens CPU 207 is started (step <S > 01).

  Next, in step S02, the camera CPU 111 determines whether the focusing mode is the phase difference detection method or the TV-AF using the setting unit 103. If the phase difference detection method is used, the camera CPU 111 proceeds to step S10 and is controlled according to a known flow. . In the present embodiment, description is omitted. When the focus mode in TV-AF is selected, the process proceeds to S03.

  In S03, it is determined whether or not the ON signal of the first stroke switch (SW1) in the release means 107 is generated. When the ON signal is generated, the camera CPU 111 communicates with the lens CPU 207, and the mounted lens device. Is acquired by the camera CPU 111. The acquired information at this time includes whether the lens apparatus is compatible with TV-AF, focal length, current subject distance area (set by a gray code pattern (not shown) in the lens apparatus 200), and the like. (S04) The photometry unit 105 measures the light and transmits it to the camera CPU 111.

  In S05, it is determined whether or not the mounted lens device 200 is a lens compatible with TV-AF. If it is compatible with TV-AF, the process proceeds to S06. If the lens is compatible only with conventional control, the process proceeds to S11.

  In S06, the camera CPU 111 calculates the evaluation value by the TV-AF, and performs driving at a predetermined speed based on the result (S07). If the focus lens group is not abnormally stopped, it is detected in S08, and if it is abnormally stopped without focusing, re-driving is performed based on the evaluation value at that time.

  If driving is in progress, the TV-AF evaluation value is continuously updated to determine in-focus, and if in-focus, the process proceeds to S22. If not in focus, the process returns to S06 and is driven at a speed based on the TV-AF evaluation value. Keep doing.

  In S22, it is determined whether or not an ON signal is input from the second stroke switch (SW2) of the release means 107, and S02 to S09 are repeated until an ON signal is input. When the ON signal from SW2 is input, the process proceeds to S23.

  In S23, the camera CPU 111 starts the exposure operation of the imaging unit 108. The lens CPU 207 controls the aperture driving unit 205 so that the aperture 204 has a predetermined value during the exposure operation. When the exposure ends, the process proceeds to S24, where the camera CPU 111 records the captured image data on a recording medium (not shown) by the recording device 114, and returns to S02.

  In S11, even if the lens is not compatible with TV-AF, it is determined whether the lens device can perform the above-described pseudo speed control (second focusing control), and the camera. Judgment is made by comparing with data stored in the CPU 111. If it corresponds to the second focus control, the process proceeds to S12, and if not, the process proceeds to S18.

  In S12, based on the acquired lens information, driving of the lens is started by the control described in FIG. 3, and an evaluation value of TV-AF is obtained in S13. In this embodiment, 12 pulses ahead are started as the drive target position. In S14, it is determined whether or not the focus lens group is abnormally stopped. If the focus lens group is abnormally stopped, the process returns to S12 and resetting is started to reset the drive target position from that position. If driving is in progress, the process proceeds to S15, where it is determined from the TV-AF evaluation value whether focus is achieved. If not focused, whether a predetermined amount before the drive target position has been reached in S16 (this embodiment). (The remaining pulses are 3 to 6 pulses), and if reached, the drive target position based on the remaining pulses at that time is updated in S17, and the TV-AF evaluation value is obtained in S13. If it is determined in S15 that the focus is achieved, the process proceeds to S22.

  Since the lens device cannot perform drive control as described in FIGS. 3 and 4 in S18, after obtaining the current TV-AF evaluation value, the drive direction is determined, and in S19, minute pulse drive, for example, 4 pulses is performed. Drive minutes. The TV-AF evaluation value is calculated in S20, and minute pulse driving is repeated until it is determined that the focus is achieved in S20. Needless to say, when the TV-AF evaluation value is reversed in all the controls, the driving direction is also reversed. After determining in-focus in S21, the process proceeds to S22.

  The camera CPU 111 and the lens CPU 207 repeat the above series of operations until the power of the setting unit 103 is turned off. When the power is turned off, the communication between the camera CPU 111 and the lens CPU 207 is finished, and the power to the lens-side electric circuit 200 is turned on. Supply is also terminated.

  With the above configuration, even when a lens device that does not support driving of the TV-AF is mounted on the camera system, it is possible to perform focusing control with as little discomfort as possible.

  In this embodiment, the embodiment is a single-focus lens. However, the zoom lens can obtain the same focal length information, set an appropriate drive target position, and set the drive command output timing appropriately. Can be controlled. Further, the region F of the target drive speed region G is G ± 2 mm / S, but this value and region vary depending on the cameras constituting the camera system, and may be set to an appropriate amount based on the camera conditions. .

It is a block diagram which shows the camera system of this embodiment. It is a figure showing the relationship between the image plane moving speed and drive residual pulse showing drive control of the camera system of this embodiment. It is the figure which represented the C section in FIG. 2 in detail. It is a figure showing the pseudo speed control with the lens which does not respond | correspond to TV-AF in the camera system of this embodiment. 6 is a flowchart showing main operations of the camera system of the present embodiment. It is a figure showing the image plane moving speed and drive residual pulse showing the focusing operation | movement by the conventional phase difference detection system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Camera 108 Image pick-up element 109 AF processing circuit 111 Camera CPU
200 Lens device 20
203 Focus lens group 207 Lens CPU
208 Focus drive unit 209 Focus lens position detection means

Claims (6)

A photographic optical system having a focus lens group movable on the optical axis for focus adjustment, a drive unit for driving the focus lens group, and a position detection means for detecting the position of the focus lens group A lens device;
It is possible to perform a first focusing control for detecting a focus state from an imaging element and an output of the imaging element and controlling the driving speed of the focus lens group in a predetermined speed range toward a focusing position. In a camera system composed of a camera,
When a lens device that does not support driving based on the first focus control and controls the focus lens group based on the driving target position is mounted on the camera, unique information of the lens device is displayed on the camera side. Based on the determination result, the driving of the focus lens group is stopped by the second focusing control in which the driving target position and the output timing of the driving command are changed instead of the first focusing control. A camera system that is driven in a predetermined speed range in the first focusing control without focusing.   The position detection means detects a pulse signal generated by movement of a focus lens group, the second focus control outputs a drive command based on the number of remaining pulses up to the drive target position, and the drive command The camera system according to claim 1, wherein the output is updated before the previous drive target position, and the next drive target position is changed in accordance with the remaining drive pulses up to the previous drive target position.   The drive target position and the output timing by the second focus control are changed according to the specific information, focal length, and subject distance of the mounted lens device. Camera system.   4. The camera system according to claim 1, wherein when the focus lens group is stopped in a state in which a remaining drive pulse remains, the camera system is re-driven based on information at the time of the stop. 5. .   The camera system according to claim 1, wherein the driving unit in the lens device is an ultrasonic motor.   When the focus lens group cannot be driven in the predetermined speed range by a drive command based on the second focus control, a warning display is displayed on the display means, and intermittent drive with continuous minute drive is performed. The camera system according to claim 1, wherein the camera system is characterized in that:

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