JP5020565B2 - Photography lens drive control device and imaging device - Google Patents

Description

  The present invention relates to a photographic lens drive control device and an image pickup apparatus including the photographic lens drive control device, and more particularly to improvement of drive control of a plurality of lens groups constituting a zoom lens.

  2. Description of the Related Art Cameras that take a photograph are widely equipped with a photographic lens (so-called zoom lens) that has a zooming function that changes the magnification of photographing as necessary. This zoom lens operates between a telephoto state where a far field can be taken by operating an operation switch provided on the camera and a wide angle state where a wider field angle range can be taken. Thus, the shooting magnification can be changed. The zoom lens is configured by combining a plurality of lens groups including one or more lenses, and the imaging magnification is changed by driving (moving) each lens group in the optical axis direction.

Here, in order to drive the lens group, a mechanical mechanism (for example, a cam mechanism or the like) that interlocks the plurality of lens groups and can change the positions of the plurality of lens groups simultaneously is provided. A lens drive control device that drives the mechanism manually or by a motor is known (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 06-160699

  However, the drive control device for the taking lens described in Patent Document 1 has a problem that the structure is complicated by including the mechanical drive mechanism described above.

  On the other hand, instead of interlocking a plurality of lens groups, a motor is provided for each lens group, and each lens group is independently driven by a corresponding motor, thereby realizing a lens drive control device having a simple structure. be able to.

  However, since the plurality of lens groups constituting the zoom lens are arranged on the same optical axis, and part of the displaceable ranges of adjacent lens groups along the optical axis overlap each other, When driven in parallel, the lens groups may interfere with each other depending on the arrangement position and driving speed of each lens group along the optical axis.

  On the other hand, if the driving method is to sequentially drive and stop the plurality of lens groups from the object side (object side) or the image surface side, there is no possibility that the lens groups interfere with each other. Compared with the case where the groups are driven in parallel, the time required from the start of driving to the end of driving becomes longer. In addition, since the zoom lens generally includes a focus lens group that performs an image focusing function on the image plane, a focused image is projected onto the image plane until the drive of the focus lens group is completed. Not.

  Therefore, if this sequential drive type lens drive control device is applied to a still camera or a video camera configured to display an image projected on a built-in CCD, CMOS, or the like on a liquid crystal monitor, the image is out of focus. Is displayed for a long time, and there is a problem that the usability and the appearance of the image are poor.

  In addition, when the ambient temperature is low, the mechanical member contracts, the mechanical mechanism part, and the viscosity characteristics of the lubricant in the motor deteriorate, and the driving load increases. As a result, since the drive torque increases, the drive speed adjustment control similar to the normal temperature may not be driven.

  An object of the present invention is to drive a photographic lens capable of preventing interference between the lens groups while simultaneously driving a plurality of lens groups constituting the photographic lens by different driving means even when the ambient temperature is low. It is to provide a control device and an imaging device.

  The photographic lens drive control device and the imaging device according to the present invention simultaneously drive each lens group by a plurality of lens drive devices provided for each lens group, from the start of driving of the lens group to the end of driving. While preventing the required time from becoming longer, switching between lens groups that are subject to adjustment of drive speed according to the positional relationship between multiple lens groups prevents interference between lens groups and more than necessary deviations. Is. In addition, even when the temperature is low, a drive failure is prevented by providing a limit to each drive speed adjustment.

That is, the photographic lens drive control device according to the present invention, a plurality of lens groups responsible for zooming function, a plurality of lens driving means for respectively driving the plurality of lens groups, and the plurality of lens driving means, Control means for controlling to adjust the driving speed of at least one lens group, lens position detection means for detecting the positions of the plurality of lens groups, and temperature measurement means for measuring the ambient temperature, When the lens driving unit drives the plurality of lens groups at the same time, the control unit is configured such that, among the plurality of lens groups, the objective-side lens group and another lens group for the objective-side lens are within a predetermined range. If the speed of the other lens group is adjusted so that the objective lens group and the other lens group do not fall within the predetermined range, the objective side If the measurement result by the temperature measuring means is equal to or lower than the low temperature determination threshold value, the drive speed adjustment limit value is varied or the adjustment of the drive speed of at least one lens group is prohibited. It is characterized in that or.

  In addition, an imaging apparatus according to the present invention is characterized in that a housing is provided with imaging means and a photographing lens drive control apparatus according to the present invention.

  Here, `` driving a plurality of lens groups simultaneously '' does not mean that all the periods from the start to the end of driving coincide with each other, but in a period in which each of the plurality of lens groups is driven, It means that at least a part of the period (may be the entire period) overlaps.

  According to the photographic lens drive control device and the imaging apparatus according to the present invention configured as described above, the control unit simultaneously converts the plurality of lens drive units provided corresponding to each of the plurality of lens groups in parallel. By controlling the drive, a plurality of lens groups are driven simultaneously and in parallel, and therefore, from the start of lens group driving to the end of driving compared to a photographing lens drive control device in which the plurality of lens groups are driven sequentially. It is possible to prevent the time required for the process from becoming long.

  In addition, the control means controls the lens driving means so as to adjust the driving speed of the lens group so that the lens groups do not interfere with each other, and the lens groups interfere with each other and more than necessary. Can be prevented.

  Further, the control means switches the lens group to be adjusted for the driving speed according to the positional relationship between the plurality of lens groups detected by the lens position detecting means, so that the proximity degree or the remoteness degree between the lens groups is increased. Correspondingly, it is possible to quickly eliminate the possibility of interference and deviation more than necessary.

  Further, even when the ambient temperature is low, it is possible to prevent drive failure due to low temperature by providing a drive speed adjustment limit in each lens group.

  According to the present invention, even when the ambient temperature is low, the plurality of lens groups constituting the photographing lens are simultaneously driven by the respective driving means, thereby preventing interference between the lens groups.

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

  Embodiments of a photographing lens drive control device according to the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram illustrating a configuration of a photographic lens drive control device 100 according to the first embodiment of the present invention. The photographing lens 1 includes four lens groups each having a plurality of lenses, and is arranged in the order of the first lens group, the second lens group, the third lens group, and the fourth lens group from the objective side. Here, the first lens group and the second lens group are integrated to constitute a 1-2 lens group.

  In the following description, it is assumed that the first-second lens group is the first-second group 1A (objective-side lens group), the third lens group is the third group 1B (other lens group), and the fourth lens group is the fourth group 1C.

  The first-second lens group 1A, the third lens group 1B, and the fourth lens group 1C are arranged in the lens barrel 1D with the same optical axis. Here, between the first-second lens group 1A and the third lens group 1B, the first diaphragm 2A and the second diaphragm 2B for controlling the amount of light passing from the subject into the photographing lens 1, and the exposure time at the time of photographing are controlled. A shutter 3 is installed.

  The first-second lens group 1A and the third lens group 1B are zoom lens groups for changing the photographing magnification. The fourth lens group 1C has an image of a subject on an exposure surface (not shown) located behind the fourth lens group 1C. This is a focusing lens group for focusing. The objective side lens group 1-2 group 1A and the other lens groups 3 group 1B, 4 group 1C are each driven by a motor and move parallel to the optical axis to establish a target optical system.

  Here, the first-second group motor 4A that drives the first-second group 1A is a direct current (DC) motor, and the third-group motor 4B that drives the third-group 1B and the fourth-group motor 4C that drives the fourth-group 1C. Is a pulse motor (drive mechanism not shown).

  The DC motor is a lens driving device (lens driving means) whose driving speed changes according to the applied driving voltage, and the driving speed of the first-second lens group 1A can be increased by simply changing the applied voltage. Can be adjusted.

  In general, a DC motor can be rotated at a higher speed than a pulse motor if the supplied power is the same, and the drive current changes according to a change in load. Since the drive current increases and, as a result, the drive torque increases, a smooth operation that is resistant to load fluctuations can be obtained.

  Therefore, it is suitable for driving a cam cylinder, for example, in which the cam inclination changes (load torque changes) according to the zoom position.

  The DC motor is also a lens driving device in which the driving speed changes according to the duty ratio (ratio of the on-state time in the cycle), and can be simply changed by changing the ratio of the drive energization time input to the lens driving device. With a simple operation, the driving speed of the first-second lens group 1A can be adjusted.

  On the other hand, when the DC motor is stopped, due to inertia, a shift from the stop control to the actual stop, so-called overrun occurs, and it is difficult to stop at the desired position. In this respect, since the pulse motor is driven by giving a pulse, it is easy to stop at an arbitrary target position, but it is not strong against torque fluctuation, and is suitable for control when torque fluctuation is small. Yes.

  The first diaphragm 2A, the second diaphragm 2B, and the shutter 3 are provided with a first diaphragm motor 4D, a second diaphragm motor 4E, and a shutter motor 4F for driving the first diaphragm 2A, the second diaphragm 2B, and the shutter 3, respectively. The corresponding first diaphragm 2A, second diaphragm 2B, and shutter 3 are driven by the operations of 4E and 4F (the drive mechanism is not shown). Each of the motors 4A to 4F is electrically connected to the motor driver 5A and subjected to intensive control.

  The motor driver 5A obtains information necessary for driving and controlling each of the motors 4A to 4F, for example, driving voltage, driving timing, driving amount, driving direction, and the like from the electrically connected CPU 5B, and based on these information Then, drive control of each of the motors 4A to 4F is performed.

  Here, the motor 4 </ b> A is provided with a first-second group movement amount detection device 7 that generates a number of pulses corresponding to the number of rotations as the motor 4 </ b> A rotates. The first-second group movement amount detection device 7 is driven by an electrically connected first-second group movement amount detection device drive circuit 8. The pulse output from the first-second group movement amount detection device 7 is taken into the CPU 5B.

  The first-second group movement amount detection device 7 outputs a predetermined number of pulses such as 1280 between when the photographing lens 1 is in the most telephoto state and when it is in the most wide-angle state. Is set. Then, the entire interval between the most telephoto state and the widest angle state is divided into a predetermined number (for example, 16 equal intervals) (1 equal interval every 80 pulses), Position indicators, so-called zoom positions Zp1, Zp2,..., Zp17, are set in 17 segments of the 16 sections.

  Here, Table 1 shows the relationship between the output pulse of the first-second group movement amount detection device 7 and the zoom positions Zp1, Zp2,..., Zp17. FIG. 12 shows the positional relationship among the reference position, the zoom position, and the storage position.

  The number of pulses shown in Table 1 is counted with the reference position set to zero. When going from the reference position to the storage position, it is counted as a negative value.

  On the other hand, the third group motor 4B and the fourth group motor 4C are driven at a driving speed corresponding to the number of pulses input from the motor driver 5A in accordance with an instruction from the CPU 5B.

  Here, the number of input pulses to the third group motor 4B required to arrange the third group 1B at each zoom position Zp1 to ZP17 is set as shown in Table 1. Since the fourth group 1C is a focusing lens group, description of the position is omitted.

  Further, the first-second lens group 1A, the third lens group 1B, and the fourth lens group 1C include a first-second lens group reference position detector 9A and a third lens group reference position detector 9B that detect the respective reference positions as lens position detection means. A group reference position detection device 9C is provided to detect whether each lens group 1A, 1B, 1C is at the reference position.

  The first-second group reference position detection device 9A, the third-group reference position detection device 9B, and the fourth-group reference position detection device 9C are respectively a first-second group reference position detection device driving circuit 10A and a third group reference position detection device driving circuit 10B. It is driven by the fourth group reference position detector drive circuit 10C. Further, the positions detected by the respective group reference position detection device drive circuits 10A, 10B, 10C are taken into the CPU 5B.

  The CPU 5B includes a telephoto switch (indicated as telephoto SW in FIG. 1) 6A operated to increase the magnification of the photographing lens 1 when performing telephoto shooting, and the magnification of the photographing lens 1 when performing wide-angle photographing. A wide angle switch (indicated as wide angle SW in FIG. 1) 6B that is operated to reduce the magnification is electrically connected, and the CPU 5B controls the motors 4A, 4A for each group according to the operation of the telephoto switch 6A and the wide angle switch 6B. 4B and 4C are controlled.

  Here, the motor driver 5 </ b> A and the CPU 5 constitute a control device (control means) 5.

  The first group and the second group constituting the first-second group 1A are attached to a cam cylinder (not shown) in which the interval between the two lens groups is mechanically adjusted by a cam mechanism. When the first-second lens group 1A is driven by the motor 4A, it is mechanically driven so that the distance between the first group and the second group becomes a predetermined distance.

  Further, a temperature sensor (temperature measuring means) 6C is connected to the CPU 5A. The temperature sensor 6C outputs a different voltage value for each temperature, and the CPU 5B acquires the voltage value by performing A / D conversion. Since the temperature sensor 6C in this embodiment has a characteristic of changing 10 mV per 1 ° C., the current temperature can be grasped by storing the voltage value at an arbitrary temperature.

  Next, the basic operation of the present embodiment will be described with reference to the flowchart of FIG. 2, the timing charts of FIGS. 4 to 7, and the operation explanatory diagram of FIG.

  In the present embodiment, the driving speed of the first-second lens group motor 4A is changed by increasing or decreasing the applied voltage of the first-second lens group motor 4A according to the position of the third lens group 1B relative to the position of the first-second lens group 1A. This is an example of a drive control method for simultaneously driving the first-second group 1A and the third group 1B so that the first-second group 1A and the third group 1B do not interfere with each other.

  Here, the drive control method differs depending on whether the driving direction of the photographic lens 1 is driven from telephoto to wide angle or driven from wide angle to telephoto. The driving direction of the lens 1 will be described separately for the case of driving from the telephoto to the wide angle and the case of driving from the wide angle to the telephoto.

(Drive control from wide angle to telephoto)
First, the drive control method when the driving direction of the photographing lens 1 is driven from wide angle to telephoto will be described. 2 and 3 show a zoom operation during the drive control.

  In step S101, whether or not the driving direction of the photographing lens 1 is driven from the telephoto to the wide angle or is driven from the wide angle to the telephoto in order to determine the necessity of the retract drive control of the fourth group 1C. , Is determined.

  When the user pushes the telephoto switch 6A that drives the photographic lens 1 from the wide angle to the telephoto and the photographic lens 1 is driven from the wide angle to the telephoto (denoted as W → T in FIGS. 2 and 3), Since each lens group is driven in a direction in which the distance between the lens groups is away from each other, the retract drive control of the fourth group 1C is unnecessary, and the flow proceeds to step S103.

  In step S103, in order to determine the necessity of the retract drive control of the third group 1B, whether the driving direction of the photographing lens 1 is driven from the telephoto to the wide angle or is driven from the wide angle to the telephoto. , Is determined.

  When the user presses the telephoto switch 6A that drives the photographic lens 1 from the wide angle to the telephoto and the photographic lens 1 is driven from the wide angle to the telephoto, as described above, the direction in which the distance between the lens groups increases. Since each lens group is driven, the retract drive control of the third group 1B is unnecessary, and the flow proceeds to step S105. In step S105, the driving of the first-second lens group 1A is started by the first-second lens group driving motor 4A when the telephoto switch 6A is pressed.

  Here, since the first-second lens group driving motor 4A is a DC motor, an inrush current is generated immediately after the start of driving, and the power supply voltage drops, which affects the battery life. To avoid this, immediately after the first-second lens group 1A is started to drive, the driving voltage of the first-second lens group driving motor 4A is set to a value lower than the normal driving voltage. (See the timing chart of the telephoto switch 6A and the first-second lens group driving motor 4A in FIGS. 4 and 5).

  Note that the drive voltage between the telephoto and wide-angle positions is set relatively lower than the drive voltage between the wide-angle position and the taking lens storage position.

  This is because a high drive speed is required between the wide-angle and the taking lens storage, so that the voltage is set high, and between the telephoto and wide-angle positions, the target position is set by operating the telephoto switch 6A or the wide-angle switch 6B. This is because an appropriate voltage setting is made so that the drive is quickly stopped.

  After starting the driving of the first-second lens group 1A in step S105, the flow proceeds to step S106. In step S106, it is determined whether or not the first-second lens group 1A needs to be stopped.

  Here, when it is necessary to stop the first-second lens group 1A, that is, when the telephoto switch 6A is not pressed (when the telephoto switch 6A is turned off in FIG. 5), or when the first-second lens group 1A is When it is driven to a position closer than the predetermined distance with respect to the position on the most telephoto side (in FIG. 4, when the stop control of the first-second lens group driving motor 4A is started), the flow proceeds to step S114. On the other hand, if it is not necessary to stop the first-second lens group 1A, the flow moves to step S107.

  In step S107, it is determined whether the third group 1B is stopped or being driven. If the third group 1B is stopped here, the flow moves to step S108. On the other hand, if the third group 1B is being driven, the flow proceeds to step S110.

  In step S108, in order to give a time difference between the driving start timing of the first-second lens group 1A and the driving start timing of the third lens group 1B, it is determined whether or not a predetermined time has elapsed after the start of driving the first-second lens group 1A. The

  By giving a time difference between the drive start timing of the first-second lens group 1A and the drive start timing of the third lens group 1B, the inrush current timing generated at the start of driving of the first-second lens group motor 4A is adjusted. Since the drive currents do not overlap, it is not necessary for the power supply to supply a large current consumption in a short time. By doing in this way, it becomes possible to lengthen the lifetime of the battery which is a power supply. Determination of the elapse of the predetermined time is performed by counting the number of output pulses output from the first-second group movement amount detection device 7 until the predetermined number is reached.

  If it is determined in step S108 that a predetermined time has elapsed after the first-second lens group 1A is driven, the flow moves to step S109. On the other hand, if the predetermined time has not elapsed after the first-second lens group 1A is driven, the flow returns to step S106 to repeat the above flow.

  In step S109, the driving of the third group 1B is started by the third group motor 4B. At this time, the driving speed of the third group 1B is set to a predetermined speed, for example, the input pulse rate of the third group motor 4B is 600 pps (number of pulses per second). Thereafter, the flow returns to step S106.

  If the third group 1B is being driven in step S107, the flow moves to step S110. In step S110, the position of the third group 1B with respect to the first-second group 1A is examined, and in order to avoid interference between the first-second group 1A and the third group 1B and an unnecessary deviation, the driving speed of the third group 1B is changed. It is determined whether it is necessary.

  In addition, when the temperature is determined and it is determined that the temperature is low (0 ° C. or lower), the driving speed limit value of the third group 1B is used for the low temperature. In this embodiment, the drive speed is adjusted by adjusting the drive pulse rate, and the drive speed limit value of the third group 1B is the maximum drive pulse rate value. The maximum drive pulse rate at room temperature is 1200 pps, and the maximum drive pulse rate at low temperatures is 1000 pps.

  Here, as shown in FIG. 8, whether the position of the third group 1B is approaching the first group 1-2A beyond the first predetermined position P1 with respect to the position of the first group 1-2A (see FIG. 8). 8 (dotted line portion A1) is in a state in which the third predetermined position P2 is passed away from the first-second group 1A (dotted line portion B1 in FIG. 8), and the driving speed of the third group 1B needs to be changed. The flow moves to step S111.

  On the other hand, when the position of the third group 1B is between P1 and P2 with respect to the position of the first-second group 1A, it is unnecessary to change the driving speed of the third group 1B, and the flow returns to step S106. . Hereinafter, the interval between P1 and P2 is referred to as an inter-group holding section.

  In step S111, when the position of the third group 1B is approaching the first group 1-2A beyond P1 with respect to the position of the first group 1-2A (dotted line portion A1 in FIG. 8), the first group 1-2A Therefore, the speed of the third group 1B is reduced by a predetermined amount to avoid the interference between the first group 1-2 and the third group 1B.

  In addition, if the position of the third group 1B is farther than the first group 1-2A beyond the position of the first group 1-2 with respect to the position of the first group 1-2A (dotted line portion B1 in FIG. 8), Since there is a possibility that the distance from the third group 1B may be more than necessary, the speed of the third group 1B is accelerated by a predetermined amount, and an unnecessary difference between the first group 1-2 and the third group 1B is avoided.

  The acceleration / deceleration amount is the driving speed of the first-second lens group 1A, the position of first-second lens group 1A detected by the first-second lens group movement amount detection device 7, and the third lens group 1B calculated by the input pulse of the third-group motor 4B. An appropriate value is calculated by the CPU 5B based on the position of.

  As shown in FIG. 8, the zoom position Zp3 (N) of the third lens group 1B that establishes a predetermined magnification is set in advance with respect to the zoom position Zp12 (N) of the first-second lens group 1A (see Table 1). .

Here, the position P1 of the third group 1B that starts the deceleration of the third group 1B is 1/3 minutes between the zoom position Zp3 (N) of the third group 1B and the next zoom position Zp3 (N + 1) of the third group 1B. Only the zoom position Zp3 (N) of the third lens group 1B approaches the next zoom position Zp3 (N + 1) of the third lens group 1B. That is,
P1 = Zp3 (N) + (Zp3 (N + 1) -Zp3 (N)) / 3
It is said.

Further, the position P2 of the third group 1B where the acceleration of the third group 1B is started is a position approaching the zoom position Zp3 (N-1), which is one before the third group 1B. That is,
P2 = Zp3 (N-1)
It is said.

When the positions P1 and P2 are represented by output pulses to the third group motor 4B shown in Table 1, when the zoom position of the third group 1B is Zp3 (4) (N = 4),
P1 = 360 + (380-360) / 3 = 366
P2 = 340
It becomes.

  That is, when the zoom position of the first-second lens group 1A is Zp (4) (N = 4), when the output pulse to the third-group motor 4B becomes 366 or more, the driving speed of the third lens group 1B is reduced. When the output pulse to the third group motor 4B becomes 334 or less, the driving speed of the third group 1B is accelerated.

  Here, a method of changing the driving speed of the third group 1B according to the driving pulse rate to the third group motor 4B will be described with reference to FIG.

  The third group motor 4B is driven at a normal drive pulse rate = 800 pps, and confirms the position of the third group 1B in units of Zp (zoom position). When the position of the third group 1B is equal to or less than P2 and the distance between the groups is increased, the drive pulse rate to the third group motor 4B is increased to 1200 pps to accelerate the drive speed. (1000pps at low temperature)

  Thereafter, when the position of the third group 1B is positioned within the inter-group holding section, the drive pulse rate of the third group motor 4B is returned to the normal pulse rate of 800 pps. Further, when the position of the third group 1B becomes P1 or more and the distance between the groups with the first and second groups is narrowed, the drive pulse rate to the third group motor 4B is reduced to 500 pps and the drive speed is reduced.

  As described above, when the position of the third group 1B deviates from the inter-group holding section, by controlling the speed of the third group 1B, the interference between the first group 1-2A and the third group 1B and an excessive divergence are necessary. While avoiding, it is possible to drive the first-second lens group 1A and the third lens group 1B simultaneously.

  In step S112, the position of the third group 1B with respect to the first-second group 1A is checked, and the drive speed of the first-second group 1A is changed to avoid interference between the first-second group 1A and the third group 1B and more than necessary. Is required.

  Further, when it is determined that it is necessary to reduce the driving speed of the first-second lens group 1A in order to prevent an excessive deviation, the temperature is determined. If it is determined that the temperature is low (0 ° C. or lower), 1− The drive speed adjustment by the second group 1A is prohibited. Therefore, it is determined that no change is necessary. This is because priority is given to prevention of drive failure in the first-second lens group 1A by lowering the drive voltage rather than deviation.

  Here, as shown in FIG. 8, the position of the third group 1B exceeds the second predetermined position L1 closer to the first-second group 1A than the first predetermined position P1 with respect to the position of the first-second group 1A. It is in a state of approaching the first-second group 1A (dotted line portion A2 in FIG. 8), or exceeds the fourth predetermined position L2 farther from the first-second group 1A than the third predetermined position P2, and the first-second group If it is in a state of being away from 1A (dotted line portion B2 in FIG. 8), it is necessary to change the driving speed of the first-second lens group 1A, and the flow proceeds to step S113.

  On the other hand, when the position of the third group 1B is between L1 and L2 with respect to the position of the first group 1-2, it is unnecessary to change the driving speed of the first group 1-2A, and the flow proceeds to step S106. Return to. Hereinafter, the interval between L1 and L2 is referred to as an intergroup retention limit section.

  In step S113, when the position of the third group 1B is closer to the first group 1-2A than the position of the first group 1-2A beyond the L1 (dotted line portion A2 in FIG. 8), the first group 1-2A And the third group 1B may be interfered, the speed of the first-second group 1A is accelerated by a predetermined amount to avoid the interference between the first-second group 1A and the third group 1B.

  Further, if the position of the third group 1B is farther than the first group 1-2A from the position of the first group 1-2 with respect to the position of the first group 1-2A (dotted line B2 in FIG. 8), Since there is a possibility that the third group 1B is separated more than necessary, the speed of the first-second group 1A is reduced by a predetermined amount to avoid an unnecessary difference between the first-second group 1A and the third group 1B.

  The acceleration / deceleration amount is the driving speed of the first-second lens group 1A, the position of first-second lens group 1A detected by the first-second lens group movement amount detection device 7, and the third lens group 1B calculated by the input pulse of the third-group motor 4B. An appropriate value is calculated by the CPU 5B based on the position of.

  As shown in FIG. 8, the zoom position Zp3 (N) of the third lens group 1B that establishes a predetermined magnification is set in advance with respect to the zoom position Zp12 (N) of the first-second lens group 1A (see Table 1). .

Here, the position L1 of the third group 1B that starts the deceleration of the first-second group 1A is 1 / between the zoom position Zp3 (N) of the third group 1B and the next zoom position Zp3 (N + 1) of the third group 1B. The position is close to the next zoom position Zp3 (N + 1) of the third group 1B from the zoom position Zp3 (N) of the third group 1B by 2 minutes. That is,
L1 = Zp3 (N) + (Zp3 (N + 1) −Zp3 (N)) / 2
It is said.

Further, the position L2 of the third group 1B where acceleration of the first-second group 1A is started is a zoom position Zp3 (N-1) immediately before the third group 1B and a zoom position Zp3 (N-2) one more front. The zoom position Zp3 (N-1), which is one before the third lens group 1B, is closer to the zoom position Zp3 (N-2), which is one lens before the third lens group 1B, by 1/3 of the distance between the first lens group and the third lens group. That is,
L2 = Zp3 (N-1)-(Zp3 (N-1) -Zp3 (N-2)) / 3
It is said.

When L1 and L2 are expressed by output pulses to the third group motor 4B shown in Table 1, when the zoom position of the third group 1B is Zp3 (4) (N = 4),
L1 = 360 + (380-360) / 2 = 370
L2 = 340− (340−320) / 3 = 334
It becomes.

  That is, when the zoom position of the first-second lens group 1A is Zp (4) (N = 4), when the output pulse to the third-group motor 4B is 370 or more, the driving speed of the first-second lens group 1A is increased. When the output pulse to the third group motor 4B becomes 334 or less, the driving speed of the first-second group 1A is reduced.

  Here, a method of changing the driving speed of the first-second lens group 1A by the driving voltage of the first-second lens group 1A will be described with reference to FIG.

  As shown in FIG. 10, the first-second lens group driving motor 4A is driven at a normal driving voltage of 2.0 V, and confirms the position of the third lens group 1B in units of Zp. When the position of the third group 1B becomes L1 or more and the distance between the groups with the third group 1B is narrowed, the drive voltage to the first-second group motor 4A is increased to 2.2V to accelerate the drive speed.

  Thereafter, when the position of the third group 1B reaches the normal position, the drive voltage of the first-second group motor 4A is returned to the normal voltage of 2.0V. Further, when the position of the third group 1B becomes L2 or less and the distance between the groups increases, the drive voltage of the first-second group motor 4A is lowered to 1.8V, and the drive speed is reduced.

  As described above, when the position of the third group 1B is out of the inter-group holding limit section, by controlling the speed of the first group 1-2, the interference between the first group 1-2A and the third group 1B and more than necessary. It is possible to drive the first-second lens group 1A and the third lens group 1B at the same time while avoiding the deviation.

  After it is determined in step S106 that the first-second lens group 1A needs to be stopped, the flow proceeds to step S114. In step S114, the driving state of the third group 1B is determined. If the third group 1B is stopped here, the flow proceeds to step S116. On the other hand, if the third group 1B is being driven, the flow proceeds to step S115 and stops driving the third group 1B, and then the flow proceeds to step S116.

  In step S116, stop control of the first-second lens group 1A is performed. The first-second group 1A is driven by the first-second group motor 4A, which is a DC motor. Even if the application of the drive voltage is stopped, the rotation of the first-second group motor 4A does not stop instantaneously, A run occurs.

  In order to reduce this overrun amount, stop control is performed to lower the drive voltage of the first-second lens group driving motor 4A at the time when the first-second lens group 1A stopping operation starts (1-2 in FIGS. 4 and 5). (Refer to the timing chart of the group motor 4A). After the stop control, the flow moves to step S117.

  In step S117, the first-second lens group 1A is stopped when the number of pulses output by the first-second lens group movement amount detection device 7 reaches a predetermined number from the time when the stop control of the first-second lens group 1A is started. Therefore, the brake control (general electromagnetic brake or the like) of the first-second group motor 4A is performed, and the first-second group 1A is stopped (see the timing chart of the first-second group motor 4A in FIGS. 4 and 5). ).

  The stop position of the first-second lens group 1A includes an overrun during the brake control. After this, the flow moves to step S118. In step S118, the driving direction of the photographic lens 1 is determined in order to perform backlash control (described later) for the purpose of preventing the lens group from being displaced due to play of gears (not shown) provided in the driving mechanism. When the driving direction of the photographing lens 1 is wide-angle to telephoto (indicated as W → T in FIGS. 2 and 3), in this embodiment, it is determined that the backlash control is unnecessary, and the flow proceeds to step S120. To do.

  When the driving direction of the photographic lens 1 is from telephoto to wide angle (indicated as T → W in FIGS. 2 and 3), it is determined in this embodiment that backlash control is necessary, and the flow proceeds to step S119. The backlash control is executed.

  In step S120, position correction drive control for the third group 1B is performed (see the timing chart of the third group motor 4B in FIGS. 4 and 5). In this case, the CPU 5B calculates an appropriate stop position of the third group 1B corresponding to the final position of the first-second group 1A, and drives the third group 1B to that position. This position calculation is performed based on the position information of the first-second group 1A and the third group 1B shown in Table 1. After this, the flow moves to step S121.

  In step S121, aperture drive control is performed to set the first aperture 2A and the second aperture 2B to the aperture value corresponding to the position of the stopped lens group (the first aperture motor in FIGS. 4 and 5). 4D and the timing chart of the second diaphragm motor 4E). After this, the flow moves to step S122, and the drive control of the photographing lens 1 is finished.

(Drive control from telephoto to wide angle)
Next, the case where the driving direction of the photographing lens 1 is driven from the telephoto to the wide angle will be described. 2 and 3 show a zoom operation during the drive control.

  When the user presses the wide-angle switch 6B that drives the photographing lens 1 from the telephoto to the wide angle, and the photographing lens 1 is driven from the telephoto to the wide angle (indicated as T → W in FIGS. 2 and 3), The flow proceeds from step S101 to step S102.

  In step S102, retract drive control of the fourth group 1C is performed to move the fourth group 1C away from the third group 1B (see timing charts of the fourth group motor 4C in FIGS. 6 and 7). When the photographing lens 1 is driven from the telephoto to a wide angle, the distance between the lens groups becomes close, and there is a possibility that the third group 1B and the fourth group 1C cause interference.

  Therefore, when the position of the fourth group 1C is closer to the third group 1B than the predetermined position that does not interfere with the third group 1B, the predetermined position that does not cause interference when the third group 1B is driven. The retract drive control of the fourth group 1C is performed to move the fourth group 1C away from the third group 1B to the position. After this, the flow moves to step S103.

  In step S103, in order to determine the necessity of the retract drive control of the third group 1B, whether the driving direction of the photographing lens 1 is driven from the telephoto to the wide angle or is driven from the wide angle to the telephoto. , Is determined.

  When the user pushes the wide-angle switch 6B that drives the photographing lens 1 from the telephoto to the wide angle, and the photographing lens 1 is driven from the telephoto to the wide angle (indicated as T → W in FIGS. 2 and 3). The flow proceeds to step S104.

  In step S104, the retract drive control of the third group 1B is performed to move the third group 1B away from the first-second group 1A (see the timing chart of the third-group motor 4B in FIGS. 6 and 7). When the photographic lens 1 is driven from the telephoto to a wide angle, the distance between the lens groups becomes close, and there is a possibility that the third group 1B and the first and second groups 1A interfere with each other.

  For this reason, before driving the first-second lens group 1A, a predetermined distance, for example, half of the zoom position Zp3 (N) where the third lens group 1B is positioned and the zoom position Zp3 (N-1) one before the first lens group The third group 1B is moved away from the first-second group 1A by the distance, and the retreat drive control of the third group 1B is performed. After this, the flow moves to step S105.

  In step S105, when the wide-angle switch 6B is pressed, the driving of the first-second lens group 1A is started by the first-second lens group driving motor 4A. Here, since the first-second lens group driving motor 4A is a DC motor, an inrush current is generated immediately after the start of driving, and the power supply voltage drops, which affects the battery life. To avoid this, immediately after the first-second lens group 1A is driven, the driving voltage of the first-second lens group driving motor 4A is set to a value lower than the normal driving voltage. The start-up control is performed (see the timing chart of the first-second lens group driving motor 4A in FIGS. 6 and 7).

  After starting driving the first-second lens group 1A in step S105, the flow proceeds to step S106. In step S106, it is determined whether it is necessary to stop the first-second lens group 1A. Here, when it is necessary to stop the first-second lens group 1A, that is, when the wide-angle switch 6B is not pressed (when the wide-angle switch 6B is turned off in FIG. 7), or when the first-second lens group 1A is When it is driven to a position a predetermined distance before the position on the widest angle side (in FIG. 6, when the stop control of the first-second lens group driving motor 4A is started), the flow moves to step S114.

  On the other hand, if it is not necessary to stop the first-second lens group 1A, the flow moves to step S107. In step S107, it is determined whether the third group 1B is stopped or being driven. If the third group 1B is stopped here, the flow moves to step S108. On the other hand, if the third group 1B is being driven, the flow proceeds to step S110.

  In step S108, in order to give a time difference between the driving start timing of the first-second lens group 1A and the driving start timing of the third lens group 1B, it is determined whether or not a predetermined time has elapsed after the start of driving the first-second lens group 1A. Is done.

  By providing a time difference between the driving start timing of the first-second group 1A and the driving start timing of the third group 1B, it is not necessary to drive the first-second group motor 4A and the third group motor 4B simultaneously, and the power supply is short. There is no need to supply a large current consumption in time. By doing in this way, it becomes possible to lengthen the lifetime of a battery.

  Determination of the elapse of the predetermined time is performed by counting the number of output pulses output from the first-second group movement amount detection device 7 until the predetermined number is reached.

  If it is determined in step S108 that a predetermined time has elapsed after the first-second lens group 1A is driven, the flow moves to step S109. On the other hand, if the predetermined time has not elapsed after the first-second lens group 1A is driven, the flow returns to step S106 to repeat the above flow.

  In step S109, the driving of the third group 1B is started by the third group motor 4B. At this time, the driving speed of the third group 1B is set to a predetermined speed, for example, the input pulse rate of the third group motor 4B is 600 pps. Thereafter, the flow returns to step S106.

  If the third group 1B is being driven in step S107, the flow moves to step S110. In this step S110, the position of the third group 1B with respect to the first-second group 1A is examined, and in order to avoid interference between the first-second group 1A and the third group 1B and an unnecessary deviation, the driving speed of the first-second group 1A is adjusted. It is determined whether a change is necessary.

  In addition, when the temperature is determined and it is determined that the temperature is low (0 ° C. or lower), the driving speed limit value of the third group 1B is used for the low temperature. In this embodiment, the drive speed is adjusted by adjusting the drive pulse rate, and the drive speed limit value of the third group 1B is the maximum drive pulse rate value. The maximum drive pulse rate at room temperature is 1200 pps, and the maximum drive pulse rate at low temperatures is 1000 pps.

  Here, as shown in FIG. 8, whether the position of the third group 1B is approaching the first group 1-2A beyond the first predetermined position P1 with respect to the position of the first group 1-2A (FIG. 8). If the dotted line portion A1) is in a state of moving away from the first-second group 1A beyond the third predetermined position P2 (dotted line portion B1 in FIG. 8), the flow proceeds to step S111. On the other hand, if the position of the third group 1B is between P1 and P2, that is, within the inter-group holding section with respect to the position of the first-second group 1A, the flow returns to step S106.

  In step S111, when the position of the third group 1B is approaching the first group 1-2A beyond P1 with respect to the position of the first group 1-2A (dotted line portion A1 in FIG. 8), the first group 1-2A Therefore, the speed of the third group 1B is accelerated by a predetermined amount to avoid the interference between the first group 1-2 and the third group 1B.

  If the position of the third group 1B is away from the first group 1-2A beyond the position P2 with respect to the position of the first group 1-2A (dotted line portion B1 in FIG. 8), the first group 1-2 and the first group 3A Since there is a possibility that the distance from the group 1B is more than necessary, the speed of the third group 1B is reduced by a predetermined amount to avoid an unnecessary difference between the first group 1-2A and the third group 1B.

  The acceleration / deceleration amount is the driving speed of the first-second lens group 1A, the position of first-second lens group 1A detected by the first-second lens group movement amount detection device 7, and the third lens group 1B calculated by the input pulse of the third-group motor 4B. An appropriate value is calculated by the CPU 5B based on the position of.

  As shown in FIG. 8, the zoom position Zp3 (N) of the third group 1B that establishes a predetermined magnification is set in advance with respect to the zoom position Zp12 (N) of the first-second group 1A (see Table 1). .

Here, the position P1 of the third group 1B where the acceleration of the third group 1B starts is 1/3 minutes between the zoom position Zp3 (N) of the third group 1B and the next zoom position Zp3 (N + 1) of the third group 1B. Only the zoom position Zp3 (N) of the third lens group 1B approaches the next zoom position Zp3 (N + 1) of the third lens group 1B. That is,
P1 = Zp3 (N) + (Zp3 (N + 1) -Zp3 (N)) / 3
It is said.

Further, the position P2 of the third group 1B where the deceleration of the third group 1B is started is a position approaching the zoom position Zp3 (N-1), which is one before the third group 1B. That is,
P2 = Zp3 (N-1)
It is said.

When P1 and P2 are expressed by output pulses to the third group motor 4B shown in Table 1, when the zoom position of the third group 1B is Zp3 (4) (N = 4),
P1 = 360 + (380-360) / 3 = 366
P2 = 340
It becomes.

  That is, when the zoom position of the first-second lens group 1A is Zp (4) (N = 4), when the output pulse to the third-group motor 4B becomes 366 or more, the driving speed of the third lens group 1B is accelerated. When the output pulse to the third group motor 4B becomes 340 or less, the driving speed of the third group 1B is reduced.

  Here, a method of changing the driving speed of the third group 1B according to the driving pulse rate of the third group 1B will be described with reference to FIG.

  The third group 1B is driven at a normal driving pulse rate of 800pps, and the position of the third group 1B is confirmed in units of Zp. When the position of the third group 1B is equal to or greater than the position P1 and the distance between the groups is reduced, the driving speed of the third group 1B is increased to 1200 pps to accelerate the driving speed. (1000pps at low temperature)

  Thereafter, when the position of the third group 1B reaches within the inter-group holding section, the driving pulse rate of the third group 1B is returned to the normal pulse rate of 800 pps. Further, when the position of the third group 1B becomes P2 or less and the distance between the groups increases, the driving pulse rate of the third group 1B is lowered to 500 pps to reduce the driving speed.

  As described above, when the position of the third group 1B is out of the inter-group holding section, the speed of the third group 1B is controlled to avoid the interference between the first group 1-2A and the third group 1B. It becomes possible to drive the second group 1A and the third group 1B simultaneously.

  In step S112, the position of the third group 1B with respect to the first-second group 1A is checked, and the drive speed of the first-second group 1A is changed to avoid interference between the first-second group 1A and the third group 1B and more than necessary. It is determined whether or not is required.

  Further, when it is determined that it is necessary to reduce the driving speed of the first-second lens group 1A in order to prevent unnecessarily approaching, the temperature is determined. If it is determined that the temperature is low (0 ° C. or lower), 1− The drive speed limit value by Group 2 1A is for low temperature. In this embodiment, the driving speed is adjusted by the driving voltage, and the driving speed limit value of the first-second lens group 1A is the minimum driving voltage value. The lowest drive voltage for normal temperature is 1.8V, and the lowest drive voltage for bass is 1.9V.

  Here, as shown in FIG. 8, the position of the third group 1B exceeds the second predetermined position L1 closer to the first-second group 1A than the first predetermined position P1 with respect to the position of the first-second group 1A. It is in a state of approaching the first-second group 1A (dotted line portion A2 in FIG. 8), or exceeds the fourth predetermined position L2 farther from the first-second group 1A than the third predetermined position P2, and the first-second group If the state is away from 1A (dotted line portion B2 in FIG. 8), the flow proceeds to step S113. On the other hand, when the position of the third group 1B is between L1 and L2, that is, within the inter-group holding limit section with respect to the position of the first-second group 1A, the flow returns to step S106.

  In step S113, when the position of the third group 1B is closer to the first group 1-2A than the position of the first group 1-2A beyond the L1 (dotted line portion A2 in FIG. 8), the first group 1-2A Since there is a possibility that interference between the second group 1B and the third group 1B occurs, the speed of the first group 1-2A is reduced by a predetermined amount to avoid interference between the first group 1-2 1A and the third group 1B.

  Further, if the position of the third group 1B is away from the first group 1-2A beyond the position L2 with respect to the position of the first group 1-2A (dotted line portion B2 in FIG. 8), Since there is a possibility that the distance from the group 1B is more than necessary, the speed of the first-second group 1A is accelerated by a predetermined amount, and an unnecessary difference between the first-second group 1A and the third group 1B is avoided.

  The acceleration / deceleration amount is the driving speed of the first-second lens group 1A, the position of first-second lens group 1A detected by the first-second lens group movement amount detection device 7, and the third lens group 1B calculated by the input pulse of the third-group motor 4B. An appropriate value is calculated by the CPU 5B based on the position of.

  As shown in FIG. 8, the zoom position Zp3 (N) of the third lens group 1B that establishes a predetermined magnification is set in advance with respect to the zoom position Zp12 (N) of the first-second lens group 1A (see Table 1). .

Here, the position L1 of the third group 1B where acceleration of the first-second group 1A starts is 1 / between the zoom position Zp3 (N) of the third group 1B and the next zoom position Zp3 (N + 1) of the third group 1B. The position is close to the next zoom position Zp3 (N + 1) of the third group 1B from the zoom position Zp3 (N) of the third group 1B by 2 minutes. That is,
L1 = Zp3 (N) + (Zp3 (N + 1) −Zp3 (N)) / 2
It is said.

In addition, the position L2 of the third group 1B that starts the deceleration of the first-second group 1A is the zoom position Zp3 (N-1) that is one before the third group 1B and the zoom position Zp3 (N-2) that is one more before. The zoom position Zp3 (N-1), which is one before the third lens group 1B, is closer to the zoom position Zp3 (N-2), which is one lens before the third lens group 1B, by 1/3 of the distance between the first lens group and the third lens group. That is,
L2 = Zp3 (N-1)
It is said.

When L1 and L2 are expressed by output pulses to the third group motor 4B shown in Table 1, when the zoom position of the third group 1B is Zp3 (4) (N = 4),
L1 = 360 + (380-360) / 2 = 370
L2 = 340− (340−320) / 3 = 334
It becomes.

  That is, when the zoom position of the first-second lens group 1A is Zp (4) (N = 4), when the output pulse to the third-group motor 4B is 370 or more, the driving speed of the first-second lens group 1A is increased. When the speed is reduced and the output pulse to the third group motor 4B becomes 334 or less, the driving speed of the first-second group 1A is accelerated.

  Here, a method of changing the driving speed of the first-second lens group 1A according to the driving voltage to the first-second lens group motor will be described with reference to FIG.

  As shown in FIG. 10, the first-second lens group driving motor 4A is driven with a normal driving voltage of 2.0 V, and confirms the third lens group 1B position in units of Zp. When the third group 1B position becomes L2 or less and the inter-group distance increases, the drive voltage to the first-second group motor 4A is increased to 2.2V to accelerate the drive speed.

  Thereafter, when the third group 1B position reaches the normal position, the drive voltage to the first-second group motor 4A is returned to the normal voltage of 2.0V. In addition, when the position of the third group 1B is L1 or more and the distance between the groups is narrowed, the driving voltage to the first-second group motor 4A is lowered to 1.8V and the driving speed is reduced (at low temperatures, 1.9V).

  As described above, when the position of the third group 1B is out of the inter-group holding limit section, the speed of the third group 1B is controlled to avoid interference between the first group 1-2 and the third group 1B. -Group 1A and Group 3B can be driven simultaneously.

  After it is determined in step S106 that the first-second lens group 1A needs to be stopped, the flow proceeds to step S114. In step S114, the driving state of the third group 1B is determined. If the third group 1B is stopped here, the flow proceeds to step S116. On the other hand, when the third group 1B is being driven, the flow proceeds to step S115 and stops driving the third group 1B, and then the flow proceeds to step S116.

  In step S116, stop control of the first-second lens group 1A is performed. The first-second group 1A is driven by the first-second group motor 4A, which is a DC motor. Even if the application of the drive voltage to the first-second group motor 4A is stopped, the first-second group motor 4A The rotation does not stop instantaneously and an overrun occurs.

  In order to reduce this overrun amount, stop control is performed to reduce the drive voltage of the first-second lens group driving motor 4A at the time when the first-second lens group 1A stopping operation starts (1-2 in FIGS. 6 and 7). (Refer to the timing chart of the group motor 4A). After the stop control, the flow moves to step S117.

  In step S117, in order to stop the first-second lens group 1A when the number of pulses output by the first-second lens group movement amount detection device 7 reaches a predetermined number from the time when the stop control of the first-second lens group 1A is started. The first-second group motor 4A is brake controlled (general electromagnetic brake, etc.) to stop the first-second group 1A (see the timing chart of the first-second group motor 4A in FIGS. 6 and 7). . The stop position of the first-second lens group 1A includes an overrun during the brake control. After this, the flow moves to step S118.

  In step S118, the driving direction of the photographing lens 1 is determined in order to perform backlash control (described later) for the purpose of preventing the positional deviation of the lens group due to play of gears (not shown) provided in the driving mechanism. When the driving direction of the photographing lens 1 is from telephoto to wide angle (indicated as T → W in FIGS. 2 and 3), in this embodiment, the backlash control is performed, and therefore the flow proceeds to step S119.

  In step S119, the backlash control of the first-second lens group 1A is performed (see the timing chart of the first-second lens group driving motor 4A in FIGS. 6 and 7). In the backlash control, the first-second lens group 1A is driven until the predetermined stop position is exceeded, and then the first-second lens group 1A is driven again in the reverse direction, that is, from the wide angle to the telephoto direction. This is done by returning to the position.

  The gears of the normal drive mechanism have a play, and the exact position cannot be determined as it is. Therefore, the play is avoided so that the drive direction of the drive portion is always in one direction. After the backlash control is executed, the flow moves to step S120.

  In step S120, position correction drive control for the third group 1B is performed (see the timing chart of the third group motor 4B in FIGS. 6 and 7). In this case, the CPU 5B calculates an appropriate stop position of the third group 1B corresponding to the final position of the first-second group 1A, and drives the third group 1B to that position. This position calculation is performed based on the position information of the first-second group 1A and the third group 1B shown in Table 1. After this, the flow moves to step S121.

  In step S121, aperture drive control for setting the first aperture 2A and the second aperture 2B to the aperture value corresponding to the position of the stopped lens group is performed (the first aperture motor 4D in FIGS. 6 and 7). (Refer to the timing chart of the second diaphragm motor 4E). After this, the flow moves to step S122, and the drive control of the photographing lens 1 is finished.

  The inter-group holding section and the inter-group holding limit section may be different in the case of driving from wide angle to telephoto and in the case of driving from telephoto to wide angle. Moreover, you may change for every zoom position.

  In the present embodiment, the backlash control is performed in the case of driving from the telephoto to the wide angle, but may be performed in the case of driving from the wide angle to the telephoto.

  As described above in detail, according to the photographic lens drive control device 100 of the present embodiment, the 1-2 group 1A and the 3 group 1B, which are a plurality of lens groups having a zooming function, and these 1-2 groups. 1A, 3rd group 1B, the 1st-2 group motor 4A, 3rd group motor 4B, 1st 2nd group motor 4A, 3rd group motor 4B which drive the drive speed adjustable, respectively. A CPU 5B that controls the drive speed to be adjusted, and a first-second lens group reference position detection device 9A that functions as a lens position detection unit that detects the positions of the first-second lens group 1A and the third lens group 1B, respectively. When the first-second group motor 4A and the third-group motor 4B drive the first-second group 1A and the third group 1B simultaneously, the CPU 5B selects the first-second group reference position detection device 9A and the third group reference position. 1-2 detected by the detection device 9B In accordance with the positional relationship between 1A and 3 groups 1B, the 1-2 group motor 4A and 3 group motors are switched so that the lens group to be adjusted in driving speed is switched between the 1-2 group 1A and the 3 group 1B. 4B is controlled.

  As a result, the CPU 5B drives and controls the first-second group motor 4A and the third-group motor 4B simultaneously in parallel, so that the first-second group 1A and the third group 1B are driven simultaneously in parallel. Compared to the conventional photographing lens drive control device in which the first-second lens group 1A and the third lens group 1B are sequentially driven, the time required from the start of driving of the first-second lens group 1A and the third lens group 1B to the end of driving becomes longer. Can be prevented.

  Moreover, the CPU 5B sets the 1-2 group motor 4A and the 3 group motor 4B so as to adjust the driving speed of the 1-2 group 1A and the 3 group 1B so that the 1-2 group 1A and the 3 group 1B do not interfere with each other. By controlling, it is possible to prevent the first-second lens group 1A and the third lens group 1B from interfering with each other.

  Furthermore, the CPU 5B adjusts the drive speed according to the positional relationship between the first-second group 1A and the third group 1B detected by the first-second group reference position detection device 9A and the third-group reference position detection device 9B. By switching the first lens group between the first-second lens group 1A and the third lens group 1B, depending on the degree of proximity and the degree of divergence between the first-second lens group 1A and the third lens group 1B, The risk of overdoing can be quickly resolved.

  Further, according to the photographing lens drive control device 100 of the present embodiment, the switching of the lens group (1-2 group 1A, 3 group 1B) whose drive speed is to be adjusted by the CPU 5B is changed to 1-2 group 1A and 3 When the third group 1B approaches the first-second group 1A on the objective side beyond the first predetermined position P1 with respect to the first-second group 1A on the objective side among the first group and the first group, The driving speed of the third group 1B is adjusted so that the third group 1B is not further approached, and the second group 1B is closer to the second group 1A than the first predetermined position P1. This is a switch for adjusting the driving speed of the first-second lens group 1A so that the first-second lens group 1A and the third lens group 1B do not further approach when the first-second lens group 1A approaches the first-second lens group 1A.

  Accordingly, when the third group 1B approaches the first group 1-2A beyond the first predetermined position P1 with respect to the first group 1-2 (1A approach), the driving speed of the third group 1B is increased. By adjusting, it is possible to prevent the first-second lens group 1A and the third lens group 1B from approaching each other, and the third lens group 1B is more than the first predetermined position P1. When approaching the first-second group 1A beyond the second predetermined position L1 close to the second group 1A (second-stage approach), the adjustment of the driving speed is switched to the first-second group 1A, and the first-second group By adjusting the driving speed of 1A, the driving speeds of the first-second group 1A and the third group 1B were adjusted (the driving speed of the third group 1B was adjusted in the approach of the first stage, and 3 in the approach of the second stage. The driving speed of the group 1B remains the adjusted speed, and the driving speed of the 1-2 group 1A is adjusted.) The degree depending on increases, it is possible to increase the degree to relieve approach.

  In the photographing lens drive control device 100 of the present embodiment, the switching of the lens group (1-2 group 1A, 3 group 1B) to be adjusted by the CPU 5B with respect to the driving speed is switched with respect to the 1-2 group 1A. When the third group 1B deviates from the first-second group 1A beyond the third predetermined position P2, the driving speed of the third group 1B is adjusted so that the first-second group 1A and the third group 1B do not deviate further. When the third group 1B deviates from the first-second group 1A over the fourth predetermined position L2, which is farther from the first-second group 1A than the third predetermined position P2, This is switching for adjusting the driving speed of the first-second lens group 1A so that the second lens group 1A and the third lens group 1B do not further deviate from each other.

  As a result, when the third group 1B deviates from the first group 1-2A over the third predetermined position P2 with respect to the first 1-2 group 1A (first stage deviation), the driving speed of the third group 1B is increased. By adjusting, it is possible to prevent the first-second group 1A and the third group 1B from further deviating from each other. When the vehicle deviates from the first-second group 1A beyond the fourth predetermined position L2 close to the second-group 1A (second-stage deviation), the drive speed adjustment is switched to the first-second group 1A, and the first-second group By adjusting the driving speed of 1A, the driving speeds of the first-second group 1A and the third group 1B were adjusted (the driving speed of the third group 1B was adjusted at the first stage deviation, and three at the second stage deviation. (The driving speed of the first group 1B is adjusted while the driving speed of the first group 1B remains the adjusted speed.) Depending on the degree of release becomes higher, it is possible to increase the degree to relieve divergence.

  Further, according to the photographic lens drive control device 100 of the present embodiment, the driving speed of the third group motor 4B changes according to the input pulse rate, and therefore the driving input to the third group motor 4B. The driving speed of the third group 1B can be adjusted by a simple operation that only changes the pulse rate.

  Since the pulse motor as the third group motor 4B that changes the driving speed in accordance with the pulse rate is driven by applying a pulse, the third group 1B that is the drive target can be stopped at an arbitrary position. Although it is easy, it is not strong against torque fluctuation, and is suitable for control when torque fluctuation is small.

  Further, according to the photographic lens drive control device 100 of the present embodiment, the first-second lens group driving motor 4A has a driving speed that changes in accordance with the applied driving voltage. The driving speed of the first-second lens group 1A can be adjusted with a simple operation by simply changing the driving voltage applied to the first lens group.

  The DC motor as the first-second lens group driving motor 4A that changes the driving speed according to the applied driving voltage can be rotated at a higher speed than the pulse motor if the supplied power is the same. Since there is a characteristic that the drive current changes in accordance with the change in the load, the drive current increases as the load increases, and as a result, the drive torque increases. Therefore, a smooth operation that is resistant to load fluctuations can be obtained.

  Therefore, it is suitable, for example, for driving a cam cylinder in which the cam inclination changes (load torque changes) according to the zoom position.

  Further, according to the photographic lens drive control device 100 of the present embodiment, the first-second lens group driving motor 4A whose driving target is the first-second lens group 1A is a direct current motor, and the third lens group whose driving target is the third lens group 1B. Since the motor 4B is a pulse motor, the third group 1B can be accurately driven in accordance with the movement of the first-second group 1A.

  Next, the photographic lens drive control device 100 according to the second embodiment of the present invention will be described.

(Drive speed control by duty drive control)
In this embodiment, the driving speed is changed by increasing or decreasing the driving ratio (duty ratio) of the first-second lens group 1A according to the position of the third lens group 1B relative to the position of the first-second lens group 1A. This is an example of a drive control method for simultaneously driving the first-second group 1A and the third group 1B so that the third group 1B does not interfere with the first group.

  The drive ratio in this embodiment is a drive output ratio within a fixed interval, where 100% is full output, 50% is half output and half off, and 0% is full off.

  Here, since the difference between the present embodiment and the first embodiment described above is only the content of step S113 in the flowchart of FIG. 2, the content of step S113 in the present embodiment will be described below with reference to FIG. Do.

(Control from wide angle to telephoto)
First, a case where the driving direction of the photographing lens 1 is driven from wide angle to telephoto will be described.

  The 1-2 group 1A is driven at a normal drive ratio of 80% (10 [msec] interval, 8 [msec] ON, 2 [msec] OFF), and confirms the position of the 3 group 1B in units of Zp. .

  In step S113, when the position of the third group 1B is approaching the first group 1-2A beyond the second predetermined position L1 with respect to the position of the first group 1-2A (dotted line portion A2 in FIG. 8), Since the distance between the groups becomes narrow and interference between the first-second group 1A and the third group 1B may occur, the speed of the first-second group 1A is accelerated by a predetermined amount, and the first-second group 1A and the third group 1B To avoid interference.

  That is, the drive ratio of the first-second lens group driving motor 4A is increased to 100% (10 [msec] ON, 0 [msec] OFF at 10 [msec] intervals) to accelerate the drive speed. Thereafter, when the position of the third group 1B reaches the normal position, the drive ratio of the first-second group motor 4A is returned to the normal ratio of 80%.

  Further, if the position of the third group 1B is farther than the first group 1-2A beyond the fourth predetermined position L2 with respect to the position of the first group 1-2A (dotted line portion B2 in FIG. 8), the group Since the distance between the first and second groups 1A and 3B may increase more than necessary, the speed of the first and second groups 1A is reduced by a predetermined amount, and the first and second groups 1A and 1A Avoid unnecessary deviation from Group 3 1B.

  That is, the driving speed of the first-second lens group driving motor 4A is reduced to 60% (10 [msec] ON, 6 [msec] ON, 4 [msec] OFF) to reduce the driving speed.

  However, when it is determined that it is necessary to reduce the driving speed of the first-second lens group 1A in order to prevent an excessive deviation, the temperature is determined. If it is determined that the temperature is low (0 ° C. or lower), 1− The drive speed adjustment by the drive ratio by the second group 1A is prohibited. This is because priority is given to prevention of drive failure of the first-second lens group 1A by lowering the drive ratio rather than deviation.

  Note that the conditions of the positional relationship between L1 and L2 and other processing contents are the same as those in the first embodiment and are not described because they are duplicated.

(Control from telephoto to wide angle)
Next, the case where the driving direction of the photographing lens 1 is driven from the telephoto to the wide angle will be described.

  The first-second group motor 4A is driven at a normal driving ratio of 80% (10 [msec] intervals, 8 [msec] ON, 2 [msec] OFF), and the position of the third group 1B is set in units of Zp. Check.

  In step S113, when the position of the third group 1B is close to the first group 1-2A beyond the second predetermined position L1 with respect to the position of the first group 1-2A (dotted line portion A2 in FIG. 8), Since the distance may decrease and interference between the first-second group 1A and the third group 1B may occur, the speed of the first-second group 1A is reduced by a predetermined amount, and the first-second group 1A and the third group 1B Avoid interference.

  That is, the driving speed of the first-second lens group driving motor 4A is reduced to 60% (10 [msec] ON, 6 [msec] ON, 4 [msec] OFF) to reduce the driving speed. Thereafter, when the position of the third group 1B reaches the normal position, the drive ratio of the first-second group motor 4A is returned to the normal ratio of 80%.

  Further, if the position of the third group 1B is farther than the first group 1-2A beyond the fourth predetermined position L2 with respect to the position of the first group 1-2A (dotted line portion B2 in FIG. 8), the group Since the distance between the first and second groups 1A and 3B may increase more than necessary, the speed of the first and second groups 1A is accelerated by a predetermined amount, and the first and second groups 1A and 1A Avoid unnecessary deviation from Group 3 1B.

  That is, the drive ratio of the first-second lens group driving motor 4A is increased to 100% (10 [msec] ON, 0 [msec] OFF at 10 [msec] intervals) to accelerate the drive speed.

  However, when it is determined that it is necessary to reduce the driving speed of the first-second lens group 1A in order to prevent unnecessarily approaching, if the temperature is determined and it is determined that the temperature is low (0 ° C. or lower), 1− The driving speed adjustment by the driving ratio by the second group 1A is for low temperature. That is, the driving speed of the first-second lens group driving motor 4A is reduced to 70% (10 [msec] intervals, 7 [msec] ON, 3 [msec] OFF) to reduce the driving speed.

  Note that the conditions of the positional relationship between L1 and L2 and other processing contents are the same as those in the first embodiment and are not described because they are duplicated.

  As described above, when the position of the third group 1B deviates from the inter-group holding section, the speed of the first-second group 1A is controlled to avoid the interference between the first-second group 1A and the third group 1B. -Group 1A and Group 3 1B can be driven simultaneously.

  As described above, according to the photographic lens drive control device 100 of the present embodiment, the first-second lens group 1A and the third lens group 1B, which are a plurality of lens groups responsible for the zooming function, and the first-second lens group 1A, The driving speeds for the first-second group motor 4A, third-group motor 4B, first-second group motor 4A, and third-group motor 4B that drive the third group 1B so that the driving speed can be adjusted. A CPU 5B that controls to adjust the position, and a 1-2 group reference position detection device 9A and a 3 group reference position detection device 9B as lens position detection means for detecting the positions of the 1-2 group 1A and the 3 group 1B, respectively. When the first-second group motor 4A and the third-group motor 4B drive the first-second group 1A and the third group 1B simultaneously, the CPU 5B selects the first-second group reference position detection device 9A and the third group reference position detection device. 1-2 group 1A detected by 9B The 1-2 group motor 4A and the 3 group motor 4B are switched so that the lens group whose drive speed is to be adjusted is switched between the 1-2 group 1A and the 3 group 1B according to the positional relationship between the 3 groups 1B. Control.

  As a result, the CPU 5B drives and controls the first-second group motor 4A and the third-group motor 4B simultaneously in parallel, so that the first-second group 1A and the third group 1B are driven simultaneously in parallel. Compared to the conventional photographing lens drive control device in which the first-second lens group 1A and the third lens group 1B are sequentially driven, the time required from the start of driving of the first-second lens group 1A and the third lens group 1B to the end of driving becomes longer. Can be prevented.

  Moreover, the CPU 5B sets the 1-2 group motor 4A and the 3 group motor 4B so as to adjust the driving speed of the 1-2 group 1A and the 3 group 1B so that the 1-2 group 1A and the 3 group 1B do not interfere with each other. By controlling, it is possible to prevent the first-second lens group 1A and the third lens group 1B from interfering with each other.

  Furthermore, the CPU 5B adjusts the drive speed according to the positional relationship between the first-second group 1A and the third group 1B detected by the first-second group reference position detection device 9A and the third-group reference position detection device 9B. By switching the first lens group between the first-second lens group 1A and the third lens group 1B, depending on the degree of proximity and the degree of divergence between the first-second lens group 1A and the third lens group 1B, The risk of overdoing can be quickly resolved.

  In the photographic lens drive control device 100 of the present embodiment, the switching of the lens group (1-2 group 1A, 3 group 1B) whose drive speed is to be adjusted by the CPU 5B is 1-2 group 1A and 3 group. When the third group 1B approaches the first group 1-2A on the objective side beyond the first predetermined position P1 with respect to the first group 1-2A on the objective side among the first group 1B, The driving speed of the third group 1B is adjusted so that the group 1B does not further approach, and the second group 1A is closer to the second group 1A than the first predetermined position P1 to the second group 1A. When the second group 1A is approached beyond the predetermined position L1, the driving speed of the first-second group 1A is adjusted so that the first-second group 1A and the third group 1B do not further approach.

  Accordingly, when the third group 1B approaches the first group 1-2A beyond the first predetermined position P1 with respect to the first group 1-2 (1A approach), the driving speed of the third group 1B is increased. By adjusting, it is possible to prevent the first-second lens group 1A and the third lens group 1B from approaching each other, and the third lens group 1B is more than the first predetermined position P1. When approaching the first-second group 1A beyond the second predetermined position L1 close to the second group 1A (second-stage approach), the adjustment of the driving speed is switched to the first-second group 1A, and the first-second group By adjusting the driving speed of 1A, the driving speeds of the first-second group 1A and the third group 1B were adjusted (the driving speed of the third group 1B was adjusted in the approach of the first stage, and 3 in the approach of the second stage. The driving speed of the group 1B remains the adjusted speed, and the driving speed of the 1-2 group 1A is adjusted.) The degree depending on increases, it is possible to increase the degree to relieve approach.

  In the photographing lens drive control device 100 of the present embodiment, the switching of the lens group (1-2 group 1A, 3 group 1B) to be adjusted by the CPU 5B with respect to the driving speed is switched with respect to the 1-2 group 1A. When the third group 1B deviates from the first-second group 1A beyond the third predetermined position P2, the driving speed of the third group 1B is adjusted so that the first-second group 1A and the third group 1B do not deviate further. When the third group 1B deviates from the first-second group 1A over the fourth predetermined position L2, which is farther from the first-second group 1A than the third predetermined position P2, This is switching for adjusting the driving speed of the first-second lens group 1A so that the second lens group 1A and the third lens group 1B do not further deviate from each other.

  As a result, when the third group 1B deviates from the first group 1-2A over the third predetermined position P2 with respect to the first 1-2 group 1A (first stage deviation), the driving speed of the third group 1B is increased. By adjusting, it is possible to prevent the first-second group 1A and the third group 1B from further deviating from each other. When the vehicle deviates from the first-second group 1A beyond the fourth predetermined position L2 close to the second-group 1A (second-stage deviation), the drive speed adjustment is switched to the first-second group 1A, and the first-second group By adjusting the driving speed of 1A, the driving speeds of the first-second group 1A and the third group 1B were adjusted (the driving speed of the third group 1B was adjusted at the first stage deviation, and three at the second stage deviation. (The driving speed of the first group 1B is adjusted while the driving speed of the first group 1B remains the adjusted speed.) Depending on the degree of release becomes higher, it is possible to increase the degree to relieve divergence.

  Further, according to the photographic lens drive control device 100 of the present embodiment, the driving speed of the third group motor 4B changes according to the input pulse rate, and therefore the driving input to the third group motor 4B. The driving speed of the third group 1B can be adjusted by a simple operation that only changes the pulse rate.

  Since the pulse motor as the third group motor 4B that changes the driving speed in accordance with the pulse rate is driven by applying a pulse, the third group 1B that is the drive target can be stopped at an arbitrary position. Although it is easy, it is not strong against torque fluctuation, and is suitable for control when torque fluctuation is small.

  Further, according to the photographic lens drive control device 100 of the present embodiment, the first-second lens group driving motor 4A changes its driving speed according to the duty ratio, and therefore inputs to the first-second lens group driving motor 4A. The driving speed of the first-second lens group 1A can be adjusted with a simple operation by simply changing the ratio of the drive energization time.

  The DC motor as the first-second lens group driving motor 4A that changes the ratio of the drive energization time to be input can be rotated at a higher speed than the pulse motor if the supplied power is the same. Therefore, the drive current increases with an increase in load, resulting in an increase in drive torque. As a result, a smooth operation that is resistant to load fluctuations can be obtained.

  Therefore, it is suitable, for example, for driving a cam cylinder in which the cam inclination changes (load torque changes) according to the zoom position.

  Further, according to the photographic lens drive control device 100 of the present embodiment, the first-second lens group driving motor 4A whose driving target is the first-second lens group 1A is a direct current motor, and the third lens group whose driving target is the third lens group 1B. Since the motor 4B is a pulse motor, the third group 1B can be accurately driven in accordance with the movement of the first-second group 1A.

  FIG. 13 is a schematic diagram showing a digital still camera 200 (imaging device) according to Embodiment 3 of the present invention.

  The illustrated digital still camera 200 includes a two-dimensional CCD (or a two-dimensional CMOS) 120 serving as an imaging unit that converts a projected optical image into an electric signal and outputs the electric signal in a housing 110, and a two-dimensional CCD 120. This is a configuration including the above-described photographing lens drive control device 100 according to the first embodiment or the second embodiment that projects a light image thereon.

  The illustrated digital still camera 200 is an imaging device that records an image of a subject projected on the two-dimensional CCD 120 through the photographing lens 1 of the photographing lens drive control device 100. The digital still camera 200 is the above-described embodiment. Since the photographing lens drive control device 100 of Example 1 or Example 2 is provided, the CPU 5B (control device; see FIG. 1) of the photographing lens drive control device 100 corresponds to each of the lens groups 1A, 1B, and 1C. The plurality of lens groups 1A, 1B, and 1C are driven simultaneously and in parallel by driving and controlling the plurality of lens group motors 4A, 4B, and 4C provided in parallel. Compared to a conventional digital still camera having a photographing lens drive control device in which 1A, 1B, and 1C are sequentially driven, lens groups 1A and 1B The time required from 1C driving start until the drive-end can be prevented from becoming long.

  In addition, the CPU 5B controls the lens group motors 4A, 4B, and 4C so as to adjust the driving speed of the lens groups 1A, 1B, and 1C so that the lens groups 1A, 1B, and 1C do not interfere with each other. It is possible to prevent the groups 1A, 1B, and 1C from interfering with each other.

  Further, the CPU 5B switches the lens group to be adjusted in driving speed to the 1-2 group 1A or the 3 group 1B according to the position of the 1-2 group 1A and the positional relationship of the 3 group 1B. Depending on the degree of proximity and the degree of remoteness between the groups 1A and 1B, it is possible to quickly eliminate the possibility of interference and the possibility of excessive divergence.

  Moreover, each effect by the imaging lens drive control apparatus 100 of Example 1 or Example 2 mentioned above can be exhibited.

1 is a block diagram illustrating a configuration of a photographic lens drive control device according to a first embodiment of the present invention. FIG. It is a flowchart which shows the zoom operation | movement at the time of drive control. 3 is a flowchart showing a continuation of FIG. It is a timing chart of the lens drive device from wide angle to telephoto. It is a timing chart of the lens drive device from wide angle to telephoto. It is a timing chart of the lens drive device from telephoto to wide angle. It is a timing chart of the lens drive device from telephoto to wide angle. It is operation | movement explanatory drawing of a photographic lens drive control apparatus. It is a figure explaining the method of changing the drive speed of 3 groups with the drive pulse rate to the motor for 3 groups. It is a figure explaining the method to vary the drive speed of 1-2 group by the drive voltage of 1-2 group. It is a figure explaining the content of 1-2 group drive speed switching. It is a figure which shows the positional relationship of a reference position, a zoom position, and a storage position. It is a general | schematic external view which shows the digital still camera (imaging device) which concerns on Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shooting lens 1A 1-2 group lens 1B 3 group lens 1C 4 group lens 4A 1-2 group motor 4B 3 group motor 4C 4 group motor 5 Control device 5A Motor driver 5B CPU
6A telephoto SW
6B Wide-angle SW
6C Temperature sensor 9A 1-2 group reference position detection device 9B 3 group reference position detection device 9C 4 group reference position detection device

Claims (9)

A plurality of lens groups that perform a zooming function, a plurality of lens driving units that respectively drive the plurality of lens groups, and the plurality of lens driving units that adjust the driving speed of at least one lens group Control means for controlling, lens position detecting means for detecting the positions of the plurality of lens groups, respectively, and temperature measuring means for measuring the ambient temperature,
When the lens driving unit simultaneously drives the plurality of lens groups , the control unit includes a predetermined range of the lens group on the objective side and the other lens groups for the lens on the objective side among the plurality of lens groups. If the speed of the other lens group is adjusted so that it falls within the range, and the objective side lens group and the other lens group do not fall within the predetermined range, the objective side lens group In addition to performing speed adjustment, if the measurement result by the temperature measuring means is equal to or lower than the low temperature determination threshold value, the drive speed adjustment limit value is varied, or adjustment of the drive speed of at least one lens group is prohibited. A photographic lens drive control device. A plurality of lens groups that perform a zooming function, a plurality of lens driving units that respectively drive the plurality of lens groups, and the plurality of lens driving units that adjust the driving speed of at least one lens group and a control means for controlling the lens position detecting means for detecting respective positions of the plurality of lens groups, and a temperature measuring means for measuring the ambient temperature,
When the lens driving unit simultaneously drives the plurality of lens groups , the control unit is configured such that, among the plurality of lens groups, the other lens group exceeds the first predetermined position with respect to the objective lens group. When the objective lens group approaches the objective lens group, the driving speed of the other lens group is adjusted so that the objective lens group and the other lens group do not further approach, When the other lens group approaches the objective lens group beyond a second predetermined position closer to the objective lens group than the first predetermined position, the objective lens group and The drive speed of the objective lens group is adjusted so that the other lens group is not further approached, and the drive speed adjustment limit value is varied when the measurement result by the temperature measurement means is equal to or lower than the low temperature determination threshold value. Or at least one Photographing lens driving control apparatus characterized by or prohibits adjustment of the lens group driving speed. 2. The photographing lens drive control according to claim 1 , wherein the drive speed adjustment limit value is a maximum pulse rate when the drive speed of the lens driving unit changes according to an input pulse rate. apparatus. 2. The photographing lens drive according to claim 1 , wherein, when the driving speed of the lens driving unit changes according to an applied driving voltage, the driving speed adjustment limit value is a minimum driving voltage. Control device. 2. The photographing lens drive control device according to claim 1 , wherein when the drive speed changes according to a duty ratio, the drive speed adjustment limit value is a minimum duty ratio . Among the plurality of lens driving means, the lens driving means for driving the objective lens group is a DC motor, and the lens driving means for driving other lens groups is a pulse motor. The photographing lens drive control device according to claim 1 or 2 . Wherein in response to the drive voltage applied to the DC motor by changing the drive speed of the DC motor, in claim 6, wherein changing the driving speed of the pulse motor according to the pulse rate to be input to the pulse motor The photographic lens drive control device described. According to claim 6, wherein in accordance with the duty ratio of the DC motor by changing the drive speed of the DC motor, to change the driving speed of the pulse motor according to the pulse rate to be input to the pulse motor Photographic lens drive control device. An imaging apparatus comprising an imaging unit and the imaging lens drive control device according to claim 1 in a housing.

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