JP2007033657A - Light quantity adjusting device and imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light quantity adjusting device which accurately performs reset operation even if phases are shifted when attaching a stepping motor for driving a light quantity adjusting member, and also to provide an imaging apparatus. <P>SOLUTION: After performing excitation to a predetermined phase different from a reset position first, the excitation is performed to the phase of the reset position further. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging apparatus including a light amount adjusting device such as a diaphragm device.

  Conventionally, a light amount adjusting device used in a camera or the like has a galvano actuator that opens and closes two diaphragm blades according to the amount of current supplied to a drive coil, a hall element for detecting the position of the diaphragm, and a control signal for the diaphragm position. What is provided with the circuit to output is known. However, this system has a disadvantage that the number of components such as a position detection sensor (Hall element), its detection circuit, and adjustment circuit is large and complicated. In order to improve this, a diaphragm device using a stepping motor has been proposed in recent years.

  For example, in a light amount adjusting device configured such that the mechanical operating angle is less than 270 degrees in electrical angle, the excitation force of the stepping motor that drives the light amount adjusting member becomes a strong phase position near the middle position of the driving range. Install the motor. A method of determining the initial position by exciting the phase is well known.

  Furthermore, in Patent Document 1, the aperture blade is driven using a stepping motor, and the initial position reference is determined by mechanical (mechanical) abutment. Further, by configuring the rotor rotating mechanical angle to be within one electrical angle, the reset sensor is eliminated and the position of the blade can be reliably detected.

In Patent Document 2, an aperture device that takes a large mechanical operating angle within a range that is not limited by an electrical angle, but abuts against a mechanical end (mechanical end) provided outside a driving range that functions as a light quantity adjustment. An initial position reference is configured to be determined. At the end of the aperture operation, the stop is stopped at a position away from the middle position of the light amount adjustment range with respect to the mechanical end (mechanical end) to be abutted.
JP 2002-107772 (1st, 2nd page, FIG. 3) Japanese Patent Laying-Open No. 2005-092065 (first and second pages, FIG. 3)

  However, in the case of the light amount adjustment device that performs reset by exciting the excitation force to a strong phase, it is necessary to attach the motor to the light amount adjustment device with the phase of the motor accurately adjusted, resulting in a problem that the cost is increased.

  Furthermore, in all of the above-mentioned patent documents, since the reset is performed by abutting the mechanical end (mechanical end), it is necessary to drive the aperture more than the stroke between the close and the open. In this case, it must be driven meaninglessly while it is in contact with the machine end, and there are problems such as generation of unpleasant noise when it hits and deterioration in durability due to impact.

  In order to solve the above-described problems, the present invention includes a light amount adjusting member and a stepping motor that opens and closes the light amount adjusting member to adjust the amount of light passing through the optical system, and the operation range of the light amount adjusting member However, in the light amount adjusting device configured to have an electrical angle of less than 360 degrees of the stepping motor, the first phase position is excited and then the second phase position which is the reset phase position is excited. Thus, an initial reset operation of the stepping motor is performed.

  According to the present invention, it is possible to provide a light amount adjusting device and an imaging device that can perform a reset operation correctly even when a phase is shifted when a stepping motor that drives a light amount adjusting member is attached.

  Hereinafter, the present invention will be described in detail based on illustrated embodiments.

  FIG. 1 is a block diagram showing a schematic configuration of an image processing apparatus according to each embodiment of the present invention.

  In FIG. 1, reference numeral 100 denotes an image processing apparatus. Reference numeral 10 denotes an imaging lens, 11 denotes a light amount adjusting device such as a diaphragm, 12 denotes a shutter, and 14 denotes an imaging element that converts an optical image into an electrical signal. A gain amplifier 120 amplifies the analog signal output of the image sensor 14 to set the sensitivity of the camera, and 16 is an A / D converter that converts the analog signal output of the image sensor 14 into a digital signal. A timing generation circuit 18 supplies a clock signal and a control signal to the image sensor 14, the A / D converter 16, and the D / A converter 26, and is controlled by the memory control circuit 22 and the system control circuit 50.

  An image processing circuit 20 performs a predetermined pixel interpolation process on the data from the A / D converter 16 or the data from the memory control circuit 22. Predetermined arithmetic processing is performed using the captured image data, and a system control circuit 50 described later controls the exposure control circuit 40 and the distance measurement control circuit 42 based on the obtained arithmetic result. Specifically, these controls are AF (auto focus) processing, AE (automatic exposure) processing, and EF (flash pre-emission) processing of a TTL (through-the-lens) method. Further, the image processing circuit 20 performs predetermined arithmetic processing using captured image data, and also performs TTL AWB (auto white balance) processing based on the obtained arithmetic result.

  A memory control circuit 22 controls the A / D converter 16, the timing generation circuit 18, the image processing circuit 20, the image display memory 24, the D / A converter 26, the memory 30, and the compression / decompression circuit 32. The data of the A / D converter 16 is written into the image display memory 24 or the memory 30 via the image processing circuit 20 and the memory control circuit 22 or the data of the A / D converter 16 is directly passed through the memory control circuit 22. It is.

  A system control circuit 50 controls the entire image processing apparatus 100. The exposure control circuit 40 is controlled by calculating an appropriate exposure value based on the luminance level measured by the TTL via the memory control circuit 22.

  Reference numeral 24 is an image display memory, and 26 is a D / A converter. Reference numeral 28 denotes an image display unit including a TFT, an LCD, and the like. Display image data written in the image display memory 24 is displayed by the image display unit 28 via a D / A converter 26. If the image data captured using the image display unit 28 is sequentially displayed, the electronic viewfinder function can be realized. The image display unit 28 can arbitrarily turn on / off the display according to an instruction from the system control circuit 50. When the display is turned off, the power consumption of the image processing apparatus 100 can be greatly reduced. Can do.

  Reference numeral 30 denotes a memory for storing captured still images and moving images, and has a sufficient storage capacity for storing a predetermined number of still images and moving images for a predetermined time. Thus, even in the case of continuous shooting or panoramic imaging in which a plurality of still images are continuously captured, high-speed and large-scale image writing can be performed on the memory 30. The memory 30 can also be used as a work area for the system control circuit 50.

  A compression / decompression circuit 32 compresses / decompresses image data by adaptive discrete cosine transform (ADCT) or the like, reads an image stored in the memory 30, performs compression processing or decompression processing, and stores the processed data in the memory 30. Write.

  Reference numeral 40 denotes an exposure control circuit for controlling the light amount adjusting device 11 and the shutter 12. Reference numeral 42 denotes a distance measurement control circuit that controls the focusing of the imaging lens 10, reference numeral 44 denotes a zoom control circuit that controls zooming of the imaging lens 10, and reference numeral 46 denotes a barrier control circuit that controls the operation of the protective member 102 serving as a barrier. The exposure control circuit 40 and the distance measurement control circuit 42 are controlled using the TTL method. Based on the calculation result obtained by calculating the captured image data by the image processing circuit 20, the system control circuit 50 includes the exposure control circuit 40, The distance measurement control circuit 42 is controlled.

  Reference numeral 52 denotes a memory that stores constants, variables, programs, and the like for operation of the system control circuit 50. Reference numeral 54 denotes a display unit such as a liquid crystal display device or a speaker that displays an operation state, a message, or the like using characters, images, sounds, or the like according to execution of a program in the system control circuit 50. The display unit 54 is installed in a single or a plurality of positions near the operation unit of the image processing apparatus 100 so as to be easily visible, and is configured by a combination of, for example, an LCD, an LED, and a sounding element. In addition, the display unit 54 is partially installed in the optical viewfinder 104.

  Among the display contents of the display unit 54, what is displayed on the LCD or the like includes single shot / continuous shooting imaging display, self-timer display, compression rate display, recording pixel number display, recording number display, remaining image pickup possible number display, There are shutter speed display and aperture value display. In addition, exposure correction display, red-eye reduction display, macro imaging display, buzzer setting display, clock battery level display, battery level display, error display, information display with multiple digits, and attachment / detachment of recording media 200 and 210 There are status display, communication I / F operation display, date / time display, and the like. Among the display contents of the display unit 54, what is displayed in the optical viewfinder 104 includes in-focus display, camera shake warning display, strobe charge display, shutter speed display, aperture value display, exposure correction display, and the like. .

  Reference numeral 56 denotes an electrically erasable / recordable nonvolatile memory such as an EEPROM.

  62, 64, 66, 68, and 70 are operation members for inputting various operation instructions of the system control circuit 50, and include one or a plurality of switches, dials, touch panels, pointing by line-of-sight detection, voice recognition devices, and the like. Composed of a combination. Here, a specific description of these operation members will be given.

  Reference numeral 62 denotes a shutter switch SW1, which is turned on during the operation of a shutter switch member (not shown). When the shutter switch SW1 is turned on, an instruction to start an imaging preparation operation such as AF (autofocus) processing, AE (automatic exposure) processing, AWB (auto white balance) processing, EF (strobe preflash) processing, etc. is issued. Reference numeral 64 denotes a shutter switch SW2. The shutter switch SW2 is turned on when the operation of a shutter switch member (not shown) is completed, and instructs to start an imaging operation of a series of processes. Specifically, the signal read from the image pickup device 12 is subjected to exposure processing for writing image data into the memory 30 via the A / D converter 16 and the memory control circuit 22, and the calculation in the image processing circuit 20 and the memory control circuit 22. There is a development process used. In addition to this, a recording process is also performed in which image data is read from the memory 30, compressed by the compression / decompression circuit 32, and written to the recording medium 200 or 210. Reference numeral 66 denotes an image display ON / OFF switch, which can set ON / OFF of the image display unit 28. With this function, when imaging is performed using the optical finder 104, it is possible to save power by cutting off the current supply to the image display unit 28 including a TFT LCD or the like. Reference numeral 68 denotes a quick review ON / OFF switch, which sets a quick review function for automatically reproducing image data captured immediately after imaging. It should be noted that each embodiment particularly has a function for setting a quick review function when the image display unit 28 is turned off.

  Reference numeral 60 denotes a mode dial. In addition to auto mode, program mode, aperture priority mode, shutter speed priority mode, you can select settings according to various shooting scenes such as color conversion mode, night view mode, children shooting mode, fireworks shooting mode, underwater shooting mode, etc. It has become.

  An operation unit 70 includes various buttons and a touch panel. There are a menu button, a set button, a macro button, a multi-screen playback page break button, a strobe setting button, a single shooting / continuous shooting / self-timer switching button, a menu movement + (plus) button, and a menu movement-(minus) button. In addition, there are a playback image movement + (plus) button, a playback image-(minus) button, an image quality selection button, an exposure correction button, a date / time setting button, and the like.

  Reference numeral 80 denotes a power control circuit, which includes a battery detection circuit, a DC-DC converter, a switch circuit that switches blocks to be energized, and the like. The presence / absence of the battery, the type of battery, the remaining battery level, and the power supply voltage are detected, the DC-DC converter is controlled based on the detection result and the instruction of the system control circuit 50, and the necessary voltage is recorded for a necessary period. Supply to each part including the medium.

  Reference numeral 82 denotes a connector, 84 denotes a connector, and 86 denotes a primary battery such as an alkaline battery or a lithium battery, a secondary battery such as a NiCd battery, NiMH battery, or Li battery, an AC adapter, or the like.

  Reference numerals 90 and 94 denote interfaces with recording media such as memory cards and hard disks, and reference numerals 92 and 96 denote connectors for connecting to recording media such as memory cards and hard disks. A recording medium attachment / detachment detection device 98 detects whether or not the recording medium 200 or 210 is attached to the connectors 92 and 96.

  In each embodiment, the description is given assuming that there are two systems of interfaces and connectors for attaching the recording medium. Of course, the interface and the connector for attaching the recording medium may have a single or a plurality of systems, any number of systems. Moreover, it is good also as a structure provided with combining the interface and connector of a different standard. The interface and the connector may be configured using a PCMCIA card or a CF (compact storage device (compact flash (registered trademark)) card or the like conforming to a standard.

  Further, when the interfaces 90 and 94 and the connectors 92 and 96 are configured using a PCMCIA card, CF card, or other standard, the following operation is possible. Various communication cards such as a LAN card, a modem card, a USB card, an IEEE 1394 card, a P1284 card, a SCSI card, and a communication card such as a PHS are connected. As a result, image data and management information attached to the image data can be transferred to and from peripheral devices such as other computers and printers.

  Reference numeral 102 denotes a protective member that is a barrier that prevents the imaging unit from being soiled or damaged by covering the imaging unit including the lens 10 of the image processing apparatus 100. Reference numeral 104 denotes an optical viewfinder, which can take an image using only the optical viewfinder without using the electronic viewfinder function of the image display unit 28. In the optical viewfinder 104, some functions of the display unit 54, for example, a focus display, a camera shake warning display, a strobe charge display, a shutter speed display, an aperture value display, an exposure correction display, and the like are installed.

  A communication apparatus 110 has various communication functions such as RS232C, USB, IEEE1394, P1284, SCSI, modem, LAN, and wireless communication. Reference numeral 112 denotes a connector for connecting the image processing apparatus 100 to another device by the communication apparatus 110 or an antenna in the case of wireless communication.

  Reference numeral 200 denotes a recording medium such as a memory card or a hard disk, which includes a recording unit 202 composed of a semiconductor memory, a magnetic disk, or the like, an interface 204 with the image processing apparatus 100, and a connector 206 for connecting to the image processing apparatus 100. . Reference numeral 210 denotes a recording medium such as a memory card or a hard disk, which includes a recording unit 212 composed of a semiconductor memory, a magnetic disk, or the like, an interface 214 with the image processing apparatus 100, and a connector 216 for connecting to the image processing apparatus 100. .

  FIG. 2 is a schematic diagram showing a stepping motor for driving a light amount adjusting member of a light amount adjusting apparatus according to an embodiment of the present invention, its control circuit, and the operation of the stepping motor.

  In the following description, it is assumed that the light amount adjusting device is a diaphragm, the light amount adjusting member is a diaphragm blade, and the initial position reset of the light amount adjusting device is reset.

  In the figure, reference numeral 1 denotes a rotor magnet magnetized with two poles, 2 a stator which is one magnetic pole of an electromagnet, and 3 an A exciting coil which excites the stator 2 to generate a magnetic force. Reference numeral 4 denotes a stator that serves as a magnetic pole of the other electromagnet, and reference numeral 5 denotes a B excitation coil that excites the stator 4 to generate a magnetic force. A control circuit 6 performs energization control of the A excitation coil 3 and the B excitation coil 5.

  The two sets of electromagnets are arranged with a phase difference of 90 ° in electrical angle. That is, a stepping motor is configured in which the rotor magnet 1 rotates in synchronization with a rotating magnetic field generated by flowing an alternating current having a phase difference of 90 ° to the A excitation coil 3 and the B excitation coil 5.

  In FIG. 2A, when a current is passed through the A excitation coil 3 and the B excitation coil 5 in the direction of the arrow, the stator 2 and the stator 4 are excited as shown in the figure, and the rotor magnet 1 is magnetically balanced. Rotate. Next, when the current to the A exciting coil 3 is stopped, the rotor magnet 1 rotates to a magnetically balanced position as shown in FIG.

  Subsequently, when a current is passed through the A excitation coil 3 in the direction indicated by the arrow in FIG. 2C, the stator 2 and the stator 4 are excited as shown in the figure, and the rotor magnet 1 rotates to a magnetically balanced position. To do. When the current to the B excitation coil 5 is further stopped, the rotor magnet 1 rotates to a magnetically balanced position as shown in FIG.

  Subsequently, when a current is passed through the B excitation coil 5 in the direction indicated by the arrow in FIG. 2E, the stator 2 and the stator 4 are excited as shown in the figure, and the rotor magnet 1 rotates to a magnetically balanced position. To do. When the current to the A exciting coil 3 is further stopped, the rotor magnet 1 rotates to a magnetically balanced position as shown in FIG.

  Subsequently, when a current is passed through the A excitation coil 3 in the direction indicated by the arrow in FIG. 2G, the stator 2 and the stator 4 are excited as shown in the figure, and the rotor magnet 1 rotates to a magnetically balanced position. To do. When the current to the B exciting coil 5 is further stopped, the rotor magnet 1 rotates to a magnetically balanced position as shown in FIG.

  FIG. 2A, FIG. 2B, FIG. 2C, FIG. 2D, FIG. 2E, and FIG. 2 show current control sequences for the series A excitation coil 3 and B excitation coil 5. By repeating (f), FIG. 2 (g), and FIG. 2 (h), the rotor magnet 1 continues to rotate.

  The energization control of the exciting coil shown in FIG. 2 is described as a driving method by 1-2 phase excitation. However, as shown in FIG. 3, it is possible to drive and control the light quantity adjusting member with finer resolution by inputting a sine wave having a phase difference of 90 ° to the exciting coils 3 and 5 and performing microstep driving. It is.

  Although not shown in the drawings, the diaphragm blades are controlled to be opened and closed by transmitting the rotational motion of the rotor magnet 1 through gears, belts, connecting members, and the like.

  FIG. 4 is an example of a driving range of the diaphragm.

  The range from the machine end of the open aperture to the machine end of the minimum aperture is the aperture drive range. At this time, the motor is configured to control the driving range of the diaphragm within one rotation (360 °).

  Even with this configuration, it is possible to perform a reset by hitting the diaphragm blades on the machine end. The problem of reduced durability is a problem.

  For this reason, as a countermeasure against the above problem, a configuration has been proposed in which the phase having the strongest excitation force is set as the reset position in the vicinity of the middle of the aperture driving range as shown in FIG. As a result, the diaphragm can be accurately reset by exciting the reset position e regardless of the position of the diaphragm. However, when assembling the diaphragm, it is necessary to attach the motor so that the phase of the motor does not shift.

  When the phase of the motor attached to the diaphragm is shifted, the diaphragm cannot be accurately operated to the initial position depending on the position of the diaphragm immediately before the reset.

  FIG. 4B is an example when the phase of the motor attached to the diaphragm is shifted.

  In this configuration, when excited in the phase a or the phase h, when excited in the phase e, there is a case where it tries to rotate in the counterclockwise direction and hits the open aperture machine end.

  Here, a description will be given below of a method that can correctly perform resetting even when the motor mounting phase is shifted as described above, taking the case of FIGS. 4A and 4B as an example.

  Immediately before resetting, excitation is performed once to a phase c (hereinafter referred to as a pre-reset phase) that is 90 ° apart from the reset phase e by an electrical angle, and subsequently reset to the reset phase e. At this time, in the case of FIG. 4A in which the motor phase of the diaphragm is normally attached, the following operation is performed.

(When in phase b to c)
After being drawn into phase c, it resets normally.

(When in phase d to g)
Once pulled into phase c, it returns to phase e and resets.

(When in phase h)
It operates in the clockwise direction and hits the machine end of the minimum aperture, but resets normally when excited to phase e.

  In the case of FIG. 4B in which the phase of the motor attached to the diaphragm is shifted, the following operation is performed.

(When in phase ac, h)
After being drawn into phase c, it resets normally.

(When in phase d to g)
Once pulled into phase c, it returns to phase e and resets.

  By the above method, the reset can be surely performed regardless of the shift of the diaphragm motor mounting phase or the excitation position immediately before the reset.

  In the first embodiment described above, it has been described that the excitation is once performed in the pre-reset phase c and then the reset is performed by exciting in the reset phase e. However, the phase c or g that is 90 ° away from the reset phase e by an electrical angle may be the first phase before excitation, with the phase closer to the middle position of the aperture driving range being used as the pre-reset phase, and then resetting.

  In the first to second embodiments, the excitation is performed in the pre-reset phase, and the reset is performed by exciting the reset phase e. However, the reset phase e and the pre-reset phase are phases that exist within the aperture driving range.

  In the first to third embodiments described above, it has been described that the reset is performed with the phase having the strongest excitation force in the vicinity of the middle of the driving range of the diaphragm as the reset position. However, it goes without saying that the reset may be performed with the closest one-phase or two-phase excitation position as the reset position in the vicinity of the middle of the aperture driving range.

  In the first to fourth embodiments, the pre-reset phase has been described as the phase c that is 90 degrees away from the reset phase e by an electrical angle. However, it goes without saying that the reset may be performed with the one-phase or two-phase excitation position adjacent to the reset phase as the pre-reset phase position.

  Needless to say, in the driving method at the time of reset explained in the above embodiment, excitation to either the pre-reset phase or the reset phase is one-phase or two-phase excitation.

  FIG. 5 shows a flowchart at the start of exposure control according to an embodiment of the present invention. In S100, it is determined whether or not to start exposure control. If it is the playback mode at the start or the mode in which shooting is performed without displaying the live view, the process proceeds to N in S100 and waits for the start of exposure control. When it becomes Y in S100, as described in the above embodiment, the diaphragm phase is excited to the pre-reset phase (S101), and then the reset phase is excited (S102) to reset.

  Thereafter, the aperture blades may be moved in advance so that the aperture diameter at the start of photometry is obtained (S103).

  Next, when the shutter is opened in S104, photometry is immediately started (S105), and exposure control is performed so as to obtain an appropriate exposure (S106).

  In the present embodiment, an example of the control flow at the start of exposure control of the image pickup apparatus has been described. Needless to say, however, the order of operations in S104 is not particularly required if it is at a stage faster than photometry.

  Further, there is no problem even if the recording media 200 and 210 are composite media in which a memory card and a hard disk are integrated. Further, there is no problem even if a part of the composite medium is detachable.

  Furthermore, in the description of each of the above embodiments, the recording media 200 and 210 are described as being separated from the image processing apparatus 100 and arbitrarily connectable. However, any or all of the recording media can be connected to the image processing apparatus 100. Of course, there is no problem even if it remains fixed. Further, the recording medium 200 or 210 may be connected to the image processing apparatus 100 in any number of single or plural. In the above description, the recording media 200 and 210 are mounted on the image processing apparatus 100. However, the recording medium may have any combination of a single or a plurality of recording media.

  In addition, a storage medium in which a program code of software that realizes the functions of the above-described embodiments is recorded is supplied to the system or apparatus. It goes without saying that the same effect can be obtained when the computer (or CPU or MPU) of the system or apparatus reads and executes the program code stored in the storage medium.

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

  As the storage medium for supplying the program code, for example, a flexible disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like can be used. .

  In addition, the functions of the above-described embodiments are not only realized by executing the program code read by the computer. This includes the case where the OS (operating system) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Needless to say.

  Further, the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. After that, based on the instruction of the program code, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing, and the function of the above-described embodiment is realized by the processing. Needless to say.

It is the block diagram which showed schematic structure of the image processing apparatus which concerns on each embodiment of this invention. It is an example of the drive sequence of the stepping motor which concerns on the 1st Embodiment of this invention. It is an example of the drive waveform of the stepping motor which similarly concerns on the 1st Embodiment of this invention. It is an example of the figure which similarly shows the drive range of the light quantity adjustment apparatus which concerns on the 1st-6th embodiment of this invention, and the phase of the motor. FIG. 6 is a diagram illustrating an example of the size of a color capture frame corresponding to an enlargement magnification of a digital zoom display, showing an operation in the color conversion mode of the image processing apparatus according to the first embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image pickup lens 11 Light quantity adjustment device 12 Shutter 14 Image pick-up element 16 A / D converter 18 Timing generation circuit 20 Image processing circuit 22 Memory control circuit 24 Image display memory 26 D / A converter 28 Image display part 30 Memory 32 Image compression / compression Expansion circuit 40 Exposure control circuit 42 Distance control circuit 44 Zoom control circuit 46 Barrier control circuit 50 System control circuit 52 Memory 54 Display unit 56 Non-volatile memory 60 Mode dial switch 62 Shutter switch SW1
64 Shutter switch SW2
66 Image display ON / OFF switch 68 Quick review ON / OFF switch 70 Operation unit 80 Power control circuit 82 Connector 84 Connector 86 Power supply device 90 Interface 92 Connector 94 Interface 96 Connector 98 Recording medium attachment / detachment detection device 100 Image processing device 102 Protection member 104 Optical finder 110 Communication device 112 Connector (or antenna)
DESCRIPTION OF SYMBOLS 120 Gain amplifier 200 Recording medium 202 Recording part 204 Interface 206 Connector 210 Recording medium 212 Recording part 214 Interface 216 Connector

Claims (5)

A light amount adjusting member and a stepping motor that opens and closes the light amount adjusting member to adjust the amount of light that passes through the optical system, and the operation range of the light amount adjusting member is less than 360 electrical degrees of the stepping motor. In the light amount adjustment device configured to be,
An apparatus for adjusting light quantity, wherein an initial reset operation of the stepping motor is performed by exciting the first phase position and then exciting the second phase position.   2. The light amount adjusting device according to claim 1, wherein the first phase position and the second phase position are located within a driving range of the light amount adjusting member.   3. The light amount adjusting device according to claim 1, wherein the second phase position is one of the phase positions having the strongest excitation force of the stepping motor.   4. The light amount adjusting device according to claim 1, wherein the first phase position is a phase position adjacent to the second phase position and having the strongest excitation force. 5. 5. An image pickup apparatus according to claim 1, wherein an initial reset operation of the light quantity adjusting device is performed before exposure control is started.

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