Lens device, imaging device, control method and program

Abstract

To provide, for example, a lens device advantageous for continuously executing an operation of a relay lens group and an operation of a focus lens group.SOLUTION: A lens device has: a focus lens group; a relay lens group; a focus driving unit 107 that drives the focus lens group; a relay driving unit 102 that drives the relay lens group; and a control unit that controls the focus driving unit. When driving the focus lens group continuously from the drive of the relay lens group, the control unit controls the focus driving unit based on the speed of movement of a focal point during the drive of the relay lens group.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a lens apparatus, an imaging apparatus, a control method, and a program. [Background technology]

[0002] There is known a television camera lens device that electrically operates (adjusts) the position of a relay lens group on the optical axis. Patent Document 1 discloses adjusting the position of the relay lens group for each of a plurality of shooting modes that use different wavelength ranges. Patent Document 2 discloses returning the position of the relay lens group to an initial position. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3997471 [Patent Document 2] Japanese Patent Application Publication No. 11-281866 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Documents 1 and 2 do not take into consideration the interlocking of the operation of the relay lens group and the operation of the focus lens group. As a special image effect, a subject may be blurred by operating the relay lens group, and then the subject may be brought into focus by operating the relay lens group again, and then another subject may be brought into focus by operating the focus lens group. In this case, the speed of focus movement may suddenly change when switching between the operation of the relay lens group and the operation of the focus lens group.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a lens apparatus that is advantageous for successively operating a relay lens group and a focus lens group, for example. [Means for solving the problem]

[0006] In order to achieve the above object, a lens device of the present invention includes a focus lens group, a relay lens group, a focus driver that drives the focus lens group, a relay driver that drives the relay lens group, and a control unit that controls the focus driver, and the control unit controls the drive of the relay lens group. After When the focus lens group is driven continuously, the relay lens group Applicable Drive When Based on the speed of the focus movement hand The focus drive unit is controlled. Effect of the Invention

[0007] According to the present invention, for example, it is possible to provide a lens apparatus that is advantageous for successively operating a relay lens group and a focus lens group. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a configuration diagram of a first embodiment. [Diagram 2] FIG. 4 is a diagram showing the focus movement speed in the first embodiment. [Diagram 3] FIG. 4 is a diagram relating to focus speed determination in the first embodiment. [Figure 4] 1 is a flowchart of the first embodiment. [Diagram 5] 11 is a flowchart of a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which: Fig. 1 is a diagram showing the configuration of a lens device according to an embodiment of the present invention. EXAMPLES

[0010] A lens configuration diagram according to a first embodiment of the present invention will be described below with reference to FIG. 1. The lens device 100 allows focus adjustment by a focus lens (focus lens group) 105 and a relay lens 101. The relay lens 101 can move in the optical axis direction for flange back adjustment and focus adjustment during macro photography, and is used for focus adjustment in special effect photography. Both the focus lens 105 and the relay lens 101 can be electrically operated. The position of the focus lens 105 is detected by a focus encoder 106, and the focus lens 105 is driven by a focus driver 107. The position of the relay lens 101 is detected by a relay encoder 103, and the relay lens 101 is driven by a relay driver 102. The focus encoder 106 and the relay encoder 103 each include an encoder and a counter for counting its pulses.

[0011] Further, a focus drive signal generating unit 110 and a relay drive signal generating unit 104 are configured to generate control signals for the focus drive unit 107 and the relay drive unit 102, respectively. Next, a relay controller 300 is connected to the relay drive unit 102 via a communication unit 116, and a focus controller 200 is connected to the focus drive signal generating unit 110 via the communication unit 116, and the respective controls are input.

[0012] By constructing an imaging device having a lens device 100 and a camera device 400 having an image sensor 401 that captures an image formed by the lens device 100, it is possible to construct an imaging device that can enjoy the effects of the present invention.

[0013] A zoom lens (zoom lens group), an iris (aperture diaphragm), and an extender lens (extender lens group) that can be inserted into or removed from the optical path are also configured. In the configuration of this embodiment, only the zoom encoder 115, iris encoder 114, and extender encoder 113, which are position detection units, are described. Like the focus encoder 106 and relay encoder 103, these encoders also include an encoder and a counter that counts its pulses.

[0014] Focus sensitivity acquisition unit 111 calculates the moving speed of the focus (focal point) on the image. Focus speed determination unit (control unit) 109 determines a focus speed (drive speed of the focus lens) that matches the focus moving speed (changing speed of the focal distance) calculated by focus sensitivity acquisition unit 111, based on the state of the lens device (including at least one of the position of the focus lens and the position of the relay lens). The focus operation at the focus speed determined by focus speed determination unit 109 is an operation of focus lens 105 in a mode different from the operation of focus controller 200 or the autofocus operation (automatic control to the focus target position) using AF sensor 108.

[0015] The ROM 112 stores focus sensitivity data based on the optical state, such as the focus position, zoom position, iris position (aperture diameter), extender position (magnification based on), and relay position. The focus sensitivity acquisition unit 111 calculates the focus movement speed of the relay lens 101 based on these data.

[0016] The focus speed determination unit 109 also calculates and determines the focus speed from the focus sensitivity data stored in the ROM 112. The sensitivity data may be read out from a table or the like, or may be derived according to a predetermined calculation method.

[0017] 2 shows the change in the focal position on an image when shooting with the aim of using relay lens 101 to focus on subject 1 from a blurred state (focusing distance A) and then immediately after that, autofocus to focus on subject 2 (focusing distance B). The horizontal axis is time and the vertical axis is the focus distance.

[0018] By operating a switch in the relay controller 300, the position of the relay lens 101 can be moved to the flange back position adjusted by the camera device 400 and to a position shifted from the flange back position adjusted by the camera device 400.

[0019] 2(a) is a diagram showing a case where focus lens 105 operates in normal autofocus without the focus speed being determined by focus sensitivity acquisition unit 111 and focus speed determination unit 109. As shown in FIG. 2(a), the rate of change in the focal distance differs at time T1 between when relay lens 101 is operating (times T0 to T1) and when focus lens 105 is in autofocus operation (times T1 to T2).

[0020] 2(b) is a diagram showing a case where focus lens 105 is driven at a focus speed determined by focus sensitivity acquisition unit 111 and focus speed determination unit 109. The focus speed is set and controlled so that at time T1, the focus change speed (the speed at which the focal distance changes) caused by driving relay lens 101 is equal to the focus change speed caused by the autofocus operation that drives focus lens 105.

[0021] The AF drive at the focus speed determined by the focus speed determination unit 109 returns to the normal focus speed at a preset time (t1) after the relay lens 101 stops (time T1). Therefore, in FIG. 2(b), in the AF drive after time T4, the focus lens is driven at the normal drive speed.

[0022] Fig. 3 is a diagram showing the amount of change in focus on the horizontal axis and the positions of relay lens 101 and focus lens 105 on the vertical axis around the time when relay lens drive transitions to AF drive, which sandwiches time T1 in Fig. 2(b). Since Fig. 3 is a diagram showing the state of Fig. 2(b) in which the focal distance is proportional to time, the focal distance on the horizontal axis of Fig. 3 corresponds to a scale proportional to time. The value a on the horizontal axis is the depth of field when relay lens 101 is at the flange back position and focus lens 105 is at a position (A) where it focuses on subject 1.

[0023] Setting of the focus speed during autofocus operation of focus lens 105 (times T1 to T3 in FIG. 2(b)) will be described with reference to FIG. 3. Based on the drive speed of relay lens 101 from time T0 to T1 in FIG. 2(b) and the focus sensitivity data of relay lens 101 stored in ROM 112, the focus change speed (change in focal distance per unit time) X from the horizontal axis -4a to -a in FIG. 3 is calculated. After that, from the focus sensitivity data of focus lens 105 stored in ROM 112, the drive speed Y of focus lens 105 for moving from object distance (A) of subject 1 to object distance (B) of subject 2 is calculated so that the focus change speed becomes X.

[0024] FIG. 4 is a flow chart of this embodiment. In S101, it is confirmed whether the relay lens 101 is in operation, and if it is not in operation, the process proceeds to S112, where normal autofocus operation is performed. If the relay lens 101 is in operation, the process proceeds to S102, where autofocus is prohibited, and the process proceeds to S103.

[0025] In S103, the focus movement speed X caused by driving the relay lens is calculated, and the process proceeds to S104. In S104, it is confirmed whether the operation of the relay lens 101 is completed, and if it is not completed, the process returns to S102, and if it is completed, the process proceeds to S105.

[0026] In S105, the focus position of the subject 2 is identified by the AF sensor 108, and in S106, the drive speed Y of the focus lens during autofocus, which corresponds to the focus movement speed X of the relay lens, is calculated, and the process proceeds to S107.

[0027] In S107, the driving speed of the focus lens during autofocus is changed to Y, and the process proceeds to S108, where the timer is started.

[0028] In S109, autofocus is started. After autofocus is started in S109, in S110, it is checked whether the timer started in S108 has elapsed a specified time. If the specified time has not been reached, autofocus is continued at the drive speed of the focus lens set in S107. If the specified time has elapsed, the process proceeds to S111, where the autofocus speed is restored to the normal autofocus speed, and in S112, the process returns to the normal autofocus.

[0029] In this embodiment, the focus speed is set according to the speed at which the relay lens 101 moves from a blurred state to the in-focus direction. However, the focus speed may be set to the speed at which the relay lens 101 moves from a focused state to a blurred state in the opposite direction.

[0030] In addition, in this embodiment, the relay lens 101 and the focus lens 105 are operated individually and successively, but a preset drive in which the relay lens 101 and the focus lens 105 are driven successively may be registered, and the lenses may be driven by reproducing the preset operation.

[0031] Further, in this embodiment, the focus controller 200 and the relay controller 300 are configured separately, but since focus operation is prohibited while the relay lens 101 is in operation, they may be configured as a single controller with the same operating members for focus and relay. EXAMPLES

[0032] In the first embodiment, the relay lens 101 is used to focus on the subject 1 from a blurred state, and then the operation of focusing on the subject 2 immediately thereafter is performed by autofocus that can determine the position of the subject 2. In the second embodiment, the target subject position for the operation of focusing on the subject 2 is not determined within the lens device 100, and the focus is achieved using the focus controller 200 (manual focus operation). A detailed description will be given with reference to the flow chart of the second embodiment shown in FIG.

[0033] In S201, it is confirmed whether the relay lens 101 is being driven, and if it is not being driven, the process proceeds to S213, where a normal focusing operation is performed in response to a focus demand. If the relay lens 101 is being driven, the process proceeds to S202.

[0034] In S202, the focus controller operation is invalidated, and in S203, the focus movement speed X caused by driving the relay lens is calculated, and the process proceeds to S204.

[0035] In S204, it is confirmed whether the driving of the relay lens 101 is completed, and if it is not completed, the operations of S202 and S203 are repeated. If the driving of the relay lens 101 is completed, the process proceeds to S205.

[0036] In S205, a focus position error limit value Z is calculated to limit the position error, which is the difference between the focus lens position and the focus control, so that the focus lens drive speed Y, which corresponds to the focus movement speed X due to the drive of the relay lens, is not exceeded (so that the focus lens drive speed is equal to or lower than the movement speed of the focal point during the drive of the relay lens).

[0037] In S206, the focus position error limit value is changed to Z. In this embodiment, the drive speed of the focus lens is not set to a drive speed of the focus lens that is equal to the focus movement speed of the first embodiment. In this embodiment, an upper limit is set to the drive speed of the focus lens to limit the focus movement speed caused by driving the focus lens so that the focus movement speed caused by driving the relay lens does not exceed the focus movement speed X caused by driving the relay lens. In other words, when the focus lens is driven continuously after the operation of the relay lens, the drive speed of the focus lens is set and limited based on the focus sensitivity so that the change speed of the focus distance caused by driving the focus lens is equal to or lower than the change speed of the focus distance when the relay lens is operating.

[0038] In S207, a timer is started, and in S208, the operation of the focus controller 200 is enabled. The focus controller 200 is a controller having an operation unit with no ends, that is, a so-called endless operation unit.

[0039] In S209, it is confirmed whether the focus controller 200 is stopped. S209 is repeated until the focus controller 200 is stopped, and if the focus controller 200 is stopped, the process proceeds to S210, where communication data for setting the focus position at the time of stopping in the focus controller is transmitted from the communication unit 116 to the focus controller 200. In S211, it is confirmed whether the timer started in S207 has elapsed a specified time. If the specified time has not been reached, the process returns to S209, and if the specified time has elapsed, the focus position error limit is returned to the normal value in S212, and normal focus controller operation is resumed.

[0040] In this embodiment, when the focus lens 105 is driven continuously after the operation of the relay lens 101, the drive speed of the focus lens 105 is determined based on the change speed of the object distance with the depth of field as a reference (scale). This makes it possible to avoid giving an uncomfortable feeling regarding the focus state of the image during and after the transition from the operation of the relay lens 101 to the driving of the focus lens 105.

[0041] (Other Examples) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions. By controlling the switching from relay lens operation to focus lens operation in this manner, it is possible to prevent a sudden change in focus movement speed at the time of switching, which may cause an uncomfortable feeling to a person viewing the captured image.

[0042] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0043] 101 Relay Lens 102 Relay driver 105 Focus Lens 107 Focus drive unit 109 Focus speed determination unit (control unit)

Claims

1. A focus lens group, A relay lens group; a focus driving unit that drives the focus lens group; a relay driver that drives the relay lens group; A control unit that controls the focus drive unit, The control unit controls the focus drive unit based on the focal point movement speed during the driving of the relay lens group when the focus lens group is driven consecutively after the driving of the relay lens group.

2. The lens device according to claim 1 , wherein the control unit obtains the movement speed based on a state of the lens device.

3. 3. The lens device according to claim 2, wherein the state of the lens device relates to at least one of the position of the focus lens group and the position of the relay lens group.

4. 4. The lens apparatus according to claim 2, further comprising a zoom lens group, and the state of the lens apparatus relates to a position of the zoom lens group.

5. 5. The lens device according to claim 2, further comprising an aperture diaphragm, and the state of the lens device relates to an aperture diameter of the aperture diaphragm.

6. 6. The lens device according to claim 2, further comprising an extender lens group that can be inserted into or removed from an optical path, and the state of the lens device relates to the insertion or removal of the extender lens group.

7. 7. The lens device according to claim 2, wherein the control unit controls the focus driving unit based on a focus state.

8. The lens device according to any one of claims 2 to 6, characterized in that the control unit controls the focus drive unit so that the focal point movement speed during the driving of the focus lens group is equal to or less than the focal point movement speed during the driving of the relay lens group.

9. 9. The lens apparatus according to claim 8, wherein the control unit controls the focus driving unit based on a speed of change of an object distance and a depth of field.

10. 10. The lens apparatus according to claim 1, wherein the control unit controls the focus driving unit based on a target position of the focus lens group that is stored in advance.

11. 11. The lens device according to claim 1, wherein the control unit controls the focus drive unit so as not to drive the focus lens group when driving the relay lens group.

12. A lens device as described in any one of claims 1 to 11, characterized in that the driving of the relay lens group focuses on a subject at a first focusing distance, and the driving of the focus lens group focuses on a subject at a second focusing distance different from the first focusing distance.

13. A lens device described in any one of claims 1 to 12, characterized in that the relay lens group is movable in the optical axis direction for flange back adjustment.

14. 14. An imaging device comprising: a lens device according to claim 1; and an imaging element for capturing an image formed by the lens device.

15. A method for controlling a lens apparatus having a focus lens group and a relay lens group, comprising the steps of: a control method for controlling the driving of the focus lens group based on a focal point movement speed during the driving of the relay lens group when the focus lens group is driven consecutively after the driving of the relay lens group, the control method comprising:

16. A program causing a computer to execute the control method according to claim 15.

Images