JP4541722B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus including a photographic lens position control device.

As a photographic lens position control method, a technique is disclosed in which a motor is used as a photographic lens driving means, a pulse output is generated according to the rotation of the motor, a predetermined pulse count is detected after the position of the photographic lens is detected, and the motor is stopped. (For example, refer to Patent Document 1).

In addition, there has been proposed a photographing lens position control device that reverses at a high speed when the motor is stopped, applies a brake, cuts off the power supply, and stops driving the photographing lens.
Japanese Patent Laid-Open No. 02-199416 (pages 4 to 5)

  However, in the above-described conventional example, the configuration of the position control of the taking lens is complicated, and the taking lens cannot be quickly moved to the target position.

An imaging apparatus as one aspect of the present invention includes a photographic lens that is driven in a first area used for photographing and a second area that is a storage area in the photographing apparatus body, a motor that drives the photographic lens, It has a detection means for detecting that the photographing lens is located at a predetermined position, and a control means for controlling the drive of the motor. The predetermined position is the second and second regions when the region where the optical state of the photographic lens does not change is located on the boundary side between the first region and the second region in the first region. It is set within one of the third areas, and the control means detects from the detection means during the first operation of driving the photographic lens in the direction from the second area toward the first area. According to the signal, the motor deceleration control is started in the third area, and the photographing lens is stopped in the third area.

  According to the first configuration of the imaging device of the present invention, when the predetermined position is set in one of the second and third regions, and the photographing lens is located at the predetermined position, the photographing lens is Since the motor can be controlled to decelerate within the third region, the photographic lens can be quickly stopped within the third region.

  Here, when the motor is, for example, a stepping motor, deceleration control can be performed with a simple configuration.

  Further, for example, during the first operation, that is, when the photographic lens is driven in the direction from the second region toward the first region, the stepping motor is operated at a maximum speed by pulse control or a speed on the high speed side lower than the maximum speed. By driving with, the photographing lens can be stopped in the third region in a short time.

  Examples of the present invention will be described below.

A compact camera (hereinafter abbreviated as “camera”) as an imaging apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 and 3.
FIG. 3 shows a schematic configuration of the camera, and FIG. 1 shows a shooting initial position setting mode showing a relationship between a change in the total length of the retractable shooting lens in which the total length of the shooting lens is variable, a photo interrupter output signal, and a stepping motor driving state. Show.

  Among the photographic lenses, the variable power lenses 30, 31, and 32 are held by lens barrels 36, 35, and 34, respectively, and cam followers 36a, 35a, and 34a provided in the lens barrels 36, 35, and 34, respectively. Are engaged with cam groove portions 40c, 40b and 40d formed in the cam barrel 40, respectively. Reflected light from a subject incident through these photographing lenses forms an image on a light receiving surface of an image sensor (for example, CCD, CMOS image sensor) 16 and is converted into an electric signal, and then an A / D conversion circuit. 17 is converted into a digital signal, subjected to predetermined processing by the signal processing circuit 18, and then recorded as image data in the recording unit 26.

  The lens barrels 34 and 35 are guided in the optical axis direction by fixed guide shafts 37 and 38, and the lens barrel 36 is guided in the optical axis direction by a straight guide mechanism (not shown). Further, the lens barrel 34 holds an aperture / shutter device 44.

  A zoom gear 40f is formed in the cam barrel 40, and an output gear 39b of a reduction gear 39a that decelerates the rotation of the zoom motor 39 that is a stepping motor is engaged with the zoom gear 40f.

  Therefore, when the zoom motor 39 is actuated to rotate the cam barrel 40 forward and backward, the cam groove portions 40b, 40c, 40d of the cam barrel 40 and the cam followers 35a, 36a, 34a of the lens barrels 35, 36, 34 Due to the engaging action, the variable power lenses 30, 31, 32 and the diaphragm / shutter device 44 are driven in the optical axis direction.

Further, a focus lens 33 is disposed on the image plane side (image pickup element 16 side) with respect to the variable magnification lenses 30, 31, and 32. The focus lens 33 is held by a lens barrel 41, and the lens barrel 41 is guided in the optical axis direction by a straight guide mechanism (not shown ). A rack 41a is attached to the lens barrel 41, and the rack 41a meshes with a screw shaft 8a that is an output shaft of a focus motor 8 that is a stepping motor. For this reason, when the focus motor 8 operates and the screw shaft 8a rotates forward and backward, the focus lens 33 is driven in the optical axis direction by the meshing action of the rack 41a and the screw shaft 8a.

  Each of the cam barrel 40 and the lens barrel 41 is provided with photointerrupters 10 and 9 in which a light emitting element and a light receiving element are integrated, and the microprocessor 11 includes a cam between the light emitting element and the light receiving element. Since the light-shielding portions 40e and 41b provided in the lens barrel 40 and the lens barrel 41 enter and the light from the light-emitting element is not received by the light-receiving element, the reference of the variable power lenses 30, 31, and 32 and the focus lens 33 Detect position.

  The light-shielding portion 40e is set to have a shape that enables zone detection of whether the variable power lenses 30, 31, and 32 are located on the telephoto side, the wide-angle side, or the storage position. In addition, the light shielding unit 41b is set to have a shape that enables zone detection to determine whether the focus lens 33 is focused on a long-distance object or whether it is focused on a close object.

  In the memory 12 in the microprocessor 11, information (position data) relating to the distance from the reference position of the variable power lenses 30, 31, 32 to the TELE position, WIDE position, and retracted position corresponds to the rotation amount of the zoom motor 39. Stored as a number. For the focus lens 33, position data determined by the object distance and the position of the zoom lens 30, 31, 32 with respect to the reference position is stored as the number of steps corresponding to the rotation amount of the focus motor 8. Yes.

  The motors 39 and 8 which are stepping motors are driven by drive signals output from the stepping motor drive circuits 19 and 20 in response to a control signal from the microprocessor 11, respectively.

  Next, referring to FIG. 1, a zoom motor 39 as a drive source used to vary the overall length of the photographic lens, detection of the reference position of the photographic lens, and photographing that drives the zoom motor 39 a predetermined number of steps and stops it The initial position setting mode will be described.

  Here, as shown in the drawing lens of the present example, the optical state does not change at the WIDE position and its peripheral region (the entire length of the photographing lens does not change), and the wide side non-zoom region (third region); It has a tele-side non-zoom area where the optical state does not change (the total length of the taking lens does not change) at the TELE position and its peripheral area. The area from the retractable side end of the wide side non-zoom area to the TELE end is referred to as an imaging area (first area), and from the retracted side end of the wide side non-zoom area (end on the retracted side of the imaging area). The region up to the retracted end is called a non-photographing region (second region).

A control method for driving the photographic lens from the retracted end (the state in which the overall length is shortened the most) toward the photographic region will be described.
First, when the camera is turned on, the zoom motor 39 is driven and the photographing lens starts to move from the retracted end toward the photographing region. The zoom motor 39 is driven at the highest speed at which pulse control can be performed until deceleration control described later is started. However, the zoom motor 39 may be driven at a speed on the high speed side lower than the maximum speed (for example, an arbitrary speed on the high speed side such as 95% of the maximum speed).

  The photo interrupter 10 is set so that the output of the photo interrupter 10 is at the VL level when light is blocked and at the VH level when transmitted when the light shielding portion 40e provided on the cam barrel 40 passes.

  Further, in order to stop the taking lens from the retracted end to the WIDE position which is the initial photographing position, the switching from the VH level to the VL level determined by the photo interrupter 10 and the light shielding portion 40e provided in the cam barrel 40 is performed. The position, that is, the above-described reference position is arranged in a transition area that is an end area on the wide-side non-zoom area side in the non-photographing area.

  When the microprocessor 11 determines that the output of the photo interrupter 10 has been switched from VH to VL, the microprocessor 11 calculates the number of pulses (position data) corresponding to the distance from the reference position stored in the memory 12 to the WIDE position. This is read to start the deceleration control of the zoom motor 39, the combination of the pulse rate and the number of pulses for determining the optimum driving speed of the zoom motor 39 for the deceleration control is set to the first to third speeds, and the photographing lens is stopped at the WIDE position. .

  The number of stages of deceleration is not limited to the third speed, and may be determined by setting a plurality of speeds even at the first speed according to the target performance.

  A method for controlling the photographic lens of this embodiment will be described with reference to FIG. In addition, since the schematic structure of a camera is the same as that of Example 1, it attaches | subjects the same code | symbol and abbreviate | omits description.

  FIG. 2 shows a shooting initial position setting mode that represents the relationship between the change in the overall length of the shooting lens, the output signal of the photo interrupter, and the driving state of the stepping motor, as in the first embodiment.

  First, the zoom motor 39 is driven to move the photographing lens from the retracted end toward the photographing region. The zoom motor 39 is driven at the highest speed capable of pulse control until deceleration control described later is started in the same manner as in the first embodiment. However, as in the first embodiment, the zoom motor 39 may be driven at a high-speed speed lower than the maximum speed (for example, an arbitrary speed on the high-speed side such as 95% of the maximum speed).

  The photo interrupter 10 is set so that the output of the photo interrupter 10 is at the VL level when light is blocked and at the VH level when transmitted when the light shielding portion 40e provided on the cam barrel 40 passes.

  Further, switching from the VH level to the VL level determined by the photo interrupter 10 and the light shielding portion 40e provided in the cam barrel 40 in order to stop the photographing lens from the retracted state to the WIDE position which is the initial photographing position. The separation position, that is, the reference position is arranged in the wide-side non-zoom area. Here, as described in the first embodiment, the wide-side non-zoom region is a region where the optical state of the photographing lens including the WIDE position and the peripheral portion thereof does not change.

  When the microprocessor 11 determines that the output of the photo interrupter has been switched from VH to VL, the microprocessor 11 reads the number of pulses (position data) corresponding to the distance from the reference position to the wide position stored in the memory 12. Then, the deceleration control of the zoom motor 39 is started, the combination of the pulse rate and the pulse number for determining the optimum driving speed of the zoom motor 39 for the deceleration control is set to the first to third speeds, and the photographing lens is stopped at the WIDE position. .

  The number of stages of deceleration is not limited to the third speed, and may be determined by setting a plurality of speeds even at the first speed according to the target performance.

  As shown in FIGS. 1 and 2, the cameras of Examples 1 and 2 have a tele-side non-zoom area, but have no wide-side non-zoom area without the tele-side non-zoom area. However, the present invention can also be applied.

  The present invention can also be applied to a case where a plurality of non-zoom areas are provided between the TELE position and the WIDE position (for example, step zoom).

  Next, referring to FIG. 4, the control procedure of the taking lens in the first to third embodiments will be described. Here, FIG. 4 is a flowchart showing the control procedure of the taking lens. In addition, since the schematic structure of a camera is the same as that of Example 1, it attaches | subjects the same code | symbol and abbreviate | omits description.

First, the camera is turned on.
(S101)
It is determined whether the output of the photo interrupter 10 is at the VL level. If the VL level has not been reached, the process proceeds to S104, and if it has reached, the process proceeds to S102. Note that the flowchart shown in FIG. 4 is executed by the microprocessor 11.

(S102)
The zoom motor 39 is driven to drive the photographic lens in the retracted direction. Here, driving in the retracted direction means that, for example, when the power is turned off while driving the photographing lens to the retracted position by turning off the power, the photographing lens remains protruding from the camera body. This is because it is necessary to return the photographic lens to the retracted position.

(S103)
It is determined whether or not the output of the photo interrupter 10 has reached the VH level. If it has reached the VH level, the process proceeds to S104. If not, the process returns to S102.

(S104)
The zoom motor 39 is driven to drive the photographing lens at the retracted position toward the photographing region. The zoom motor 39 is driven at the highest speed or the lower speed than the highest speed in the pulse control as described above until the deceleration control is started.

(S105)
It is determined whether the output of the photo interrupter 10 has been switched to VL. If it has not reached the VL level, the process returns to S104, and the zoom motor 39 is continuously driven in the direction of the photographing region.

(S106)
When the VL level is reached, the zoom motor 39 is decelerated in the above-described shooting initial position setting mode, and the zoom motor 39 stops when the deceleration operation is completed. Here, the reference position may be set in the transition area as in the first embodiment, or may be set in the wide-side non-zoom area as in the second embodiment.

(S107)
After the zoom motor 39 is stopped and a predetermined time has elapsed, the photographing initial position setting mode is completed.

  Here, as a method of driving the photographic lens to the WIDE end, the photographic lens is driven from the retracted end to a position exceeding the wide-side non-zoom region, and then temporarily returned to a position on the retracted side from the WIDE position. A control method of driving to the WIDE position in order to take backlash is conceivable, but the time to drive the photographic lens to the WIDE position is better than this control method by using the control methods of the above-described embodiments. Can be shortened.

In each of the embodiments described above, the zoom motor 39 is a stepping motor. However, for example, a vibration motor or a DC motor may be used.
In the above-described embodiment, a compact camera is taken as an example. However, the present invention can be applied to, for example, a single-lens reflex camera and a video camera.

The present invention can also be applied to a camera in which the TELE position is disposed closer to the retracted side than the WIDE position.

  When the reference position and the initial shooting position are set in an area where the optical state of the taking lens does not change (an area where the entire length of the taking lens does not change), even if the photographer deliberately touches the taking lens, there are few malfunctions. Since the total length of the lens is a non-variable region, it is possible to reduce the possibility of substantially affecting the shooting angle of view, thereby improving the reliability.

Timing chart for explaining a control method of the photographing lens of Embodiment 1 Timing chart for explaining a control method of the photographing lens of Example 2 Diagram showing schematic configuration of camera Flowchart showing the control procedure of the taking lens of Examples 1 to 3

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Microprocessor 12 ... Memory 16 ... Image pick-up element 19, 20 ... Stepping motor drive circuit 30, 31, 32 ... Variable magnification lens 33 ... Focus lens 34, 35, 36, 41 ... lens barrels 34a, 35a, 36a ... cam followers 37, 38 ... fixed guide shafts 39, 8 ... motor 39a ... speed reducer 39b ... output gear 40 ... cam Lens barrels 40b, 40c, 40d ... cam groove portions 40e, 41b ... light shielding portion 40f ... zoom gear

Claims (9)

A photographic lens that is driven in a first region used for photographing and a second region that is a storage region in the photographing apparatus body;
A motor for driving the photographing lens;
Detecting means for detecting that the photographing lens is located at a predetermined position;
Control means for controlling the drive of the motor,
Before SL predetermined position, when the area where the optical state does not change in the located boundary side of the first said in the region of the first region and the second region the photographing lens and the third region, Set in one of the second and third regions,
In the first operation of driving the photographic lens in the direction from the second area toward the first area, the control means is arranged in the third area according to a detection signal from the detection means . The imaging apparatus according to claim 1, wherein deceleration control of the motor is started and the photographing lens is stopped in the third region. Wherein the predetermined position is the imaging device according to claim 1, characterized in that it is set to the third region.   A photographic lens that is driven in a first region used for photographing and a second region that is a storage region in the photographing apparatus body;
  A motor for driving the photographing lens;
  Detecting means for detecting that the photographing lens is located at a predetermined position;
  Control means for controlling the drive of the motor,
  The predetermined position is a region where the optical state of the photographing lens is not changed and is located on the boundary side between the first region and the second region in the first region, Is set in one of the second and third regions,
  In the first operation of driving the photographic lens in the direction from the second region toward the first region, the control unit is configured to detect the second region according to a detection signal from the detection unit. An image pickup apparatus, wherein deceleration control of the motor is started in an end region on the third region side, and the photographing lens is stopped in the third region. The imaging apparatus according to claim 3 , wherein the predetermined position is set in the end region.   5. The imaging apparatus according to claim 1, wherein the third region is a wide-side non-zoom region in which an optical state does not change in a wide position and a peripheral region thereof.   The control means acquires position data from the predetermined position to the wide position, starts deceleration control of the motor based on the position data, and stops the photographing lens at the wide position. The imaging device according to claim 5. The motor imaging apparatus according to any one of claims 1 to 6, characterized in that a stepping motor. 8. The imaging according to claim 7 , wherein, during the first operation, the stepping motor is driven at a maximum speed by pulse control or a speed on a high speed side lower than the maximum speed until the deceleration control is performed. apparatus. The first operation, the imaging apparatus according to any one of claims 1 to 8, characterized in that which is performed at power-on of the image pickup device.