JP2000098440A - Imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the accurate control of photographing operation corresponding to temperature change without providing a dedicated temperature sensor by arithmetically calculating ambient temperature from the difference of output from a detection means obtained on plural aperture diameters of aperture blades and information stored in a storage means. SOLUTION: Relation between temperature and the difference of Hall voltage when the aperture diameter of the diaphragm is fully opened and is fully closed is previously measured, and the relation table of the temperature and the difference of the Hall voltage is stored in a CPU 9. After power is supplied to a main body, the aperture blades 3 are fully closed without applying the voltage to the driving circuit 6 of the blades 3, and the Hall voltage is measured and stored in the CPU 9. Next, the maximum voltage is applied to the circuit 6 and the difference between the Hall voltage when the blades 3 are fully opened and is fully closed is obtained. Then, the temperature is calculated from the difference of the Hall voltage between when the blades 3 are fully opened and is fully closed and the relation between the temperature and the difference of the Hall voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imaging device.

[0002]

2. Description of the Related Art Conventionally, IG devices have been used as aperture devices for video cameras.
Meter is used. First, the configuration of the IG meter will be described with reference to FIG. In the diaphragm driving member 5 shown in FIG. 9, reference numeral 51 denotes a driving coil, and reference numeral 52 denotes a rotor integrally formed with a permanent magnet.

Reference numeral 52 denotes a shaft 52 supported by a bearing (not shown).
It is rotatable around a. Reference numeral 53 denotes a diaphragm blade driving plate which rotates integrally with the rotor 52, and includes pins 53a and 53b.
The diaphragm blade drive plate 53 is provided with a stopper 5
It is rotatable between 6a and 56b.

A spring 54 biases the diaphragm driving plate 53 in a counterclockwise direction in the figure. The aperture blades 3a and 3b are pins 5
3a and 53b, and are held by a mechanism (not shown) so as to move in parallel with each other in the direction of the arrow in FIG.

When no current flows through the drive coil 51, the diaphragm blade drive plate 53 is urged by a spring 54 in a counterclockwise direction in the figure, and is positioned by a stopper 56a.

At this time, the diaphragm blades 3a and 3b are
As shown in (a), the opening at the intersection of the dotted lines is closed. When a current flows through the drive coil 51, an electromagnetic force is generated by an interaction between the current and the permanent magnet of the rotor 52, and the rotor 52 rotates clockwise in the drawing.

[0007] With the rotation of the rotor 52, the urging force of the spring 54 also increases, and the rotation of the rotor 52 stops at a position where both are balanced. At this time, the aperture blades 3a and 3b are
As shown in (b), the opening is open.

As shown in FIGS. 9A and 9B, the aperture diameter of the aperture blades 3a and 3b changes with the rotation angle of the rotor 52. At this time, the Hall element 55 detects the amount of rotation of the permanent magnet provided integrally with the rotor 52 as a voltage (Hall voltage). Since the electromagnetic force is proportional to the current of the coil, the position of the balance, that is, the rotation angle of the rotor 52, and the aperture diameter of the aperture can be controlled by controlling the current flowing through the coil.

Next, a method of controlling a current flowing through the drive coil 51 will be described with reference to FIG.

In FIG. 10, 1 is a photographing lens, 2 is C
CD, 3 aperture blades, 4 a signal processing circuit, 5 an aperture drive member, 6 an aperture drive circuit, 8 a recording unit, 9 a CPU, 1
1 is a lens barrel drive circuit, and 13 is a lens barrel drive member.

The photographing lens 1 is composed of photographing lenses 1a and 1b, and is driven by a lens barrel drive circuit 11. CC
D2 is located on the image plane of the taking lens 1, and converts the subject image into an electric signal.

The diaphragm blade 3 is provided in the optical path of the taking lens 1, and the diaphragm driving member 5 drives the diaphragm blade 3. The signal processing circuit 4 processes the electric signal from the CCD 2 into an image signal, and records the image signal by the recording unit 8.

The signal processing circuit 4 integrates the image signal to obtain a signal (a) representing the brightness of the photographing screen.
Is making. A signal (a) indicating the brightness of the photographed screen detected by the signal processing circuit 4 is compared with a reference signal (d) indicating the brightness of the screen at the time of proper exposure, and a value obtained by multiplying the difference by a predetermined coefficient is obtained. It is added to the current drive current. Therefore, the brightness of the photographing screen is always fed back so as to approach the proper exposure.

The above is the configuration and control method of the IG meter used in the video camera.

On the other hand, it is known that the Hall voltage changes depending on the ambient temperature as shown in FIG. Therefore, depending on the ambient temperature, the aperture diameter of the diaphragm differs even with the same Hall voltage.

However, as described above, in a video camera, the aperture diameter of the aperture is feedback-controlled so that the brightness of the photographing screen always approaches the proper exposure, and is controlled by directly detecting the aperture diameter from the generated Hall voltage. No problem had arisen.

In recent years, there has been proposed an IG meter which is used as a stop camera of a still camera or a camera for both a still and a movie. In the still mode of such a still camera or a still / movie camera, it is common to determine an optimal aperture and shutter speed for a photometric value and shoot an image.

Therefore, it is required to control the aperture to an accurate aperture diameter.

Here, as described above, the Hall voltage is:
As shown in FIG. 8, it changes depending on the ambient temperature. Therefore, in these cameras, it has been considered that the temperature is separately measured using a temperature sensor or the like, and the relationship between the Hall voltage and the aperture diameter is corrected.

In addition, since the performance of the lens changes with the temperature, the focus accuracy is affected by the temperature, and the mechanical drive characteristics around the lens barrel are affected by the load variation due to the temperature. I had to switch ways. In order to measure the temperature, a temperature sensor or the like is separately used.

A method of controlling the current flowing through the drive coil 51 of the IG meter at that time will be described with reference to FIG. FIG.
Are the same as those described in the video camera shown in FIG. 10 among the configurations shown in FIG.

In FIG. 11, 1 is a photographing lens, 2 is C
CD, 3 aperture blades, 4 a signal processing circuit, 5 an aperture drive member, 6 an aperture drive circuit, 8 a recording unit, 9 a CPU, 1
0 is a switch for switching between still and movie (SW), 1
1 is a lens barrel drive circuit, 12 is a temperature sensor, 13 is a lens barrel drive member, and 14 is an AF device.

When the SW 10 is switched to the movie mode as shown in FIG. 11, the signal processing circuit 4 integrates the image signal as in the above-described video camera,
A signal (a) representing the brightness of the shooting screen is compared with a reference signal (d) representing the brightness of the screen at the time of proper exposure, and a value obtained by multiplying the difference by a predetermined coefficient is added to the current driving current. I have.

When the mode is switched to the still mode by the SW 10, the above-mentioned Hall voltage (b) is read by the CPU 9 and converted into a diaphragm aperture diameter by a voltage-aperture diameter table previously measured and recorded. (C). At that time,
The surrounding temperature is measured using the temperature sensor 12 to correct the above-mentioned voltage-opening diameter relationship. Therefore, the aperture diameter is controlled so as to always become the set aperture diameter.

As described above, the aperture of the still mode of the still camera or the still / movie camera is required to be controlled to an accurate aperture diameter. However, as shown in FIG. Varies with ambient temperature. Further, since the performance of the lens changes with the temperature, the focus accuracy is affected by the temperature, and the mechanical drive characteristics around the lens barrel are affected by the load variation due to the temperature, so that the drive (control) method is switched according to the temperature. There is a need.

As a method of detecting a temperature change, a change in the aperture diameter and the hole voltage of the IG meter due to the temperature is measured in advance, and the relationship between the hole voltage and the aperture diameter at each temperature is stored in a memory. There has been proposed a method of using the IG meter as a kind of temperature sensor in a simple manner by measuring the temperature from the output in the fully closed state using the relationship between the Hall voltage and the aperture diameter of the aperture.

[0027]

However, the change of the Hall voltage with respect to the temperature change of the aperture diameter is very small, and the method using the specific aperture diameter and temperature relationship causes noise in the output of the Hall voltage to be small. It becomes weak on the contrary.

If the rate of change of the Hall voltage of the Hall element with respect to the temperature change, that is, the slope of the characteristic indicating the relationship between the Hall voltage and the temperature is small, the influence of noise is strong.
There was a problem that accuracy was reduced.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and its object is to provide a high-precision photographing operation corresponding to a temperature change without providing a dedicated temperature sensor. An object of the present invention is to provide an imaging device that performs control.

[0030]

According to the first aspect of the present invention, there is provided a photographing lens, an aperture blade for controlling a photographing light amount of the photographing lens, and
An image pickup apparatus comprising: detecting means for detecting an aperture diameter of the aperture blade; and control means for controlling an aperture diameter of the aperture blade, wherein the control means includes a detecting means for a plurality of aperture diameters of the aperture blade. Storage means for storing information on a change in the difference between the detection outputs from the temperature due to temperature, and the difference between the outputs of the detection means obtained at the plurality of aperture diameters and the information stored in the storage means, from the surroundings. An imaging device configured to calculate a temperature is featured.

According to a second aspect of the present invention, there is provided an imaging apparatus as set forth in the first aspect, wherein the control means controls the aperture diameter of the diaphragm blade in accordance with the calculated temperature. Features the device.

According to a third aspect of the present invention, in the second aspect, a photographing lens, an AF unit for automatically adjusting a focus state of the photographing lens to a subject, and a photographing light amount of the photographing lens An imaging unit having an aperture blade and a shutter for controlling the aperture, a detection unit for detecting an aperture diameter of the aperture blade, and information on a change in a difference in detection output from the detection unit with respect to a plurality of aperture diameters of the aperture blade due to temperature. Has a storage means for storing, the difference between the output of the detection means obtained at the plurality of aperture diameters, and information stored in the storage means, to calculate the ambient temperature, based on the calculation result, An imaging apparatus comprising: a control unit configured to control an imaging unit.

According to a fourth aspect of the present invention, in the third aspect, the control means controls the aperture diameter of the diaphragm blade in accordance with the calculated temperature. It is characterized by.

According to a fifth aspect of the present invention, in the third or fourth aspect, the control means controls the operation of the shutter in accordance with the calculated temperature. Features.

According to a sixth aspect of the present invention, there is provided the imaging apparatus according to the third to fifth aspects, wherein the control means controls the AF means according to the calculated temperature. Features.

According to the invention described in claim 7 of the present application, in claim 1 or 3, the image pickup apparatus is characterized in that the plurality of aperture diameters of the aperture blade are fully closed and fully open.

According to an eighth aspect of the present invention, in the first or third aspect, the detecting means is a Hall element for detecting a rotation angle of an IG meter for driving the aperture blade, and the detection output is provided. Is an imaging device that is a Hall voltage of the Hall element.

[0038]

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

(First Embodiment) FIG. 1 is a block diagram showing a first embodiment of the present invention. Of the configuration shown in FIG.
The components having the same numbers as those shown in FIG. 11 and described in the conventional example are the same.

1 is a photographing lens, 2 is an image pickup device such as a CCD, 3 is an aperture blade, 4 is a signal processing circuit, 5 is an aperture driving member, 6 is an aperture driving circuit, 8 is a recording unit, 9 is a CPU, 10
Is a switch for switching between still and movie (SW), 11
Denotes a lens barrel driving circuit, 13 denotes a lens barrel driving member, and 14 denotes an AF device. A shutter for performing exposure control together with the aperture diameter of the aperture blade is realized by controlling the accumulation time of the image sensor.

The photographing lens 1 is composed of photographing lenses 1a and 1b, and 11 is a lens barrel driving circuit for driving the photographing lens. The CCD 2 is located on the image forming surface of the photographing lens 1 and converts a subject image into an electric signal. The diaphragm blade 3 is provided in the optical path of the imaging lens 1, and the diaphragm driving member 5 is a member that drives the diaphragm blade 3. The signal processing circuit 4 is C
The electric signal from the CD 2 is processed into an image signal. The image signal is recorded by the recording unit 8.

In this embodiment, the relationship between the difference between the Hall voltage and the temperature when the aperture diameter of the diaphragm is fully opened and fully closed as shown in FIG. 2 is measured in advance, and the relationship between the difference of the Hall voltage and the temperature is measured. The table is recorded in the CPU 9.

This CPU corresponds to the control means of the present invention, the Hall element corresponds to the detection means, and the detection output is a Hall voltage.

After the main body is turned on, first, the diaphragm blade 3 is fully closed without applying a voltage to the drive circuit 6 for the diaphragm blade 3, and the Hall voltage is measured. In the memory. This memory is CPU
The internal ROM, RAM, external EEPROM, or the like may be used, and corresponds to the storage unit of the present invention.

Next, the maximum voltage is applied to the drive circuit 6, the aperture blade 3 is fully opened, the Hall voltage is measured, and the Hall voltage when the aperture blade 3 is fully open and the Hall voltage when the aperture blade 3 is fully closed. Find the difference. The temperature can be calculated from the difference between the Hall voltage when the diaphragm blade 3 is fully opened and the hole voltage when the diaphragm blade 3 is fully closed and the relationship between the difference between the Hall voltage and the temperature.

Here, the Hall voltage when the throttle is fully opened,
As is apparent from FIG. 8, the reason for using the difference of the Hall voltage when the diaphragm is fully closed is that the slope of a straight line indicating the relationship between the diaphragm opening diameter and the Hall voltage changes depending on the temperature, and the hole diameter varies depending on the diaphragm opening diameter. The temperature change characteristics of the voltage are different.

Therefore, as shown in FIG. 2, the slope of the Hall voltage-temperature characteristic when the aperture is fully opened and the slope of the Hall voltage-temperature characteristic when the aperture is fully closed are different. In particular, in the case of FIG. The relationship is as follows.

Therefore, the Hall voltage change with respect to the temperature can be detected more remarkably and with higher accuracy by using the difference between the two characteristics than by using the characteristic of fully opening or fully closing the diaphragm alone.

If an attempt is made to discriminate the temperature change of the Hall voltage by only one of the characteristics, if the inclination of the characteristic is small,
This is because the Hall voltage detection accuracy with respect to a change in temperature decreases.

As is apparent from FIG. 2, the slope of the characteristic of the difference between when the aperture is fully opened and when the aperture is fully closed is larger than the characteristic when the aperture is fully opened and the characteristic when the aperture is fully closed. It can be seen that both the detection sensitivity and the accuracy have been improved.

Here, the relationship between the difference between the Hall voltage and the temperature when the aperture diameter is fully open and when the aperture diameter is fully closed may be the relationship between the difference between the Hall voltage and the temperature when the aperture diameter is arbitrary at two points. Good, considering the Hall element and aperture structure used,
It is preferable to use an aperture diameter where the slope of the change in the difference between the hole voltage of the two apertures and the Hall voltage with respect to the temperature is large.

The temperature can be calculated even if the temperature change of the Hall voltage is recorded in the CPU 9 in a table of the difference between the Hall voltage and the temperature.

As described above, for example, changes in the aperture diameter of the IG meter and the hole voltage due to temperature are measured in advance, and the relationship between the hole voltage and the aperture diameter at each temperature is stored in the memory. By measuring the temperature from the output of the detector in the closed state using the relationship between the Hall voltage and the aperture diameter of the aperture, the IG meter can be used as a kind of temperature sensor in a simple manner.

(Second Embodiment) This embodiment has the block configuration shown in FIG. 1 and will be described with reference to FIGS.
A method for controlling the aperture diameter of the aperture stop according to the present embodiment when the mode is switched to the still mode by the method 10 will be described.

FIG. 4 is a program diagram. First, when the release switch is half-pressed, the aperture is opened, external AF and photometry are performed by a known method, and then the shutter is released by pressing the release switch.

At this time, for example, if the photometric value is Ev = 13, the diaphragm is set to F5.
6. The shutter speed is determined to be 1/250 second. And
The CPU 9 reads the Hall voltage (b) and converts it into a signal indicating that the aperture diameter is F5.6 based on a voltage-aperture diameter relationship table measured and recorded in advance.

At this time, since the above-mentioned Hall voltage changes depending on the surrounding temperature, the Hall voltage which is measured and recorded in advance from the surrounding temperature obtained by the configuration of the first embodiment.
The relationship between the voltage and the aperture diameter is corrected so as to cancel the influence of the temperature from the relationship between the temperatures.

Accordingly, the aperture diameter is always controlled to the set aperture diameter.

Next, the shutter drive control will be described with reference to FIG. As described above, the photometric value Ev = 1
3. When the shutter is released at an aperture value of F5.6 and a shutter speed of 1/250 second, as shown in FIG. 3, after a predetermined time T1 after the charge of the CCD 9 is cleared as the front curtain, the shutter starts to close as the rear curtain.

The CPU 9 records this fixed time T1, and controls the shutter drive. At this time, the shutter drive characteristics are affected by load fluctuations and the like due to temperature.
That is, the load of the shutter drive becomes light when the temperature is high, and becomes heavy when the temperature is low.

Therefore, the break time T2 is short at high temperatures and long at low temperatures. Therefore, variations occur in the exposure accuracy. Therefore, in accordance with the detection of the ambient temperature obtained by the configuration of the first embodiment, the time T1 measured and recorded in advance is changed to stabilize the exposure accuracy. For example, since the load is lighter at 25 ° C. than at 10 ° C., the time T1 is made longer. Therefore, accurate shutter drive control can be performed.

FIG. 5 is an explanatory diagram of the autofocus (AF) device 14 of the external measurement type. In FIG. 5, 141 is a light emitting unit, 143 is a light emitting lens, 142 is a light receiving unit, 144
Is a light receiving lens, and 17 is a subject. The light emitting unit 141 emits infrared light, and the light passing through the light emitting lens 143 is reflected by the subject 17, passes through the light receiving lens 144, and
No. 2 line sensor. The angle θ reflected by the subject can be known based on where the incident light enters the line sensor, and the distance from the base length d known in advance to the subject can be known.

Here, the base length d between the light-emitting unit 141 and the light-receiving unit 142 shown in FIG. 5 changes with temperature, which affects the measurement of the focal length. The base line length d increases when the temperature is high, and decreases when the temperature is low.

Therefore, a correction is made from the ambient temperature obtained by the configuration of the first embodiment so as to cancel the influence of the temperature on the base line length d measured in advance. For example, the baseline length d at 25 ° C. is larger than that at 10 ° C.
Since the distance is long, focus on a shorter distance than the distance measurement result. Therefore, focus can always be obtained with high accuracy.

FIG. 6 is a perspective view showing the structure of the lens barrel drive unit 13. In the figure, 1c is an AF lens barrel, 19 is a DC motor,
Reference numeral 20 denotes a pulse sheet, and reference numeral 21 denotes a photo interrupter.

Based on the result of the distance measurement, the AF lens barrel 1c is moved to the AF lens barrel stop position measured and recorded in advance.

The AF drive control at this time will be described with reference to FIG. A from the AF lens barrel stop position to N1 pulse before
The motor is moved at a stroke with the F motor applied voltage Vp, and then controlled so as to maintain a constant speed until N2 pulses before the AF barrel stop position, and the AF motor applied voltage is changed when N2 pulses before the AF barrel stop position. At 0 [V], the rest is moved by inertial force to drive the AF lens barrel to the in-focus position.

Here, the mechanical drive characteristics around the lens barrel are affected by load fluctuations and the like due to temperature. That is, the load of the mechanical drive around the lens barrel becomes light when the temperature is high, and becomes heavy when the temperature is low. Therefore, the load of the AF drive becomes light when the temperature is high, and becomes heavy when the temperature is low.

For this reason, the influence of the inertial force of the AF lens barrel 1c changes, and a difference appears at the stop position of the AF lens barrel. Therefore, the value of the N2 pulse measured and recorded in advance is changed according to the ambient temperature obtained by the configuration of the first embodiment. For example, at 25 ° C., the load is lighter than at 10 ° C., so the N2 pulse is reduced. Therefore, accurate AF lens barrel drive control can be performed.

In the above embodiment, if the temperature measurement using the Hall voltage is performed only after the power is turned on, it is not possible to cope with the temperature change after the power is turned on. Also corresponds to.

Although the above embodiment is directed to an electronic still camera or a video camera having an image pickup device such as a CCD, it is apparent that the same configuration can be applied to a silver halide camera.

Further, the relationship between the Hall voltage and the aperture diameter is corrected to accurately control the aperture diameter, the performance of the lens changes with temperature, and the AF focus accuracy is affected by temperature. In addition, because the mechanical drive characteristics around the lens barrel are affected by load fluctuations and the like due to temperature, switching the drive (control) method depending on the temperature is measured by using the IG meter as a temperature sensor to measure the temperature and responding accordingly. Accurate operation can be performed by correcting or switching the control.

The relationship between the Hall voltage and the aperture diameter of the diaphragm,
Since the performance of the lens changes with the temperature and the focus accuracy is affected by the temperature, the temperature can be calculated using the IG meter as a temperature sensor and the control can be changed in accordance with the temperature to perform the control with high accuracy.

Since the IG meter and the lens barrel are close to each other, it can be considered that the temperature of the Hall element and the temperature around the lens barrel are the same, and it is possible to calculate the accurate temperature around the lens barrel drive. It is based on the fact that it can.

[0075]

As described above, according to the present invention,
A change in the difference between the Hall voltage at any two aperture diameters of the IG meter due to temperature is measured in advance, and the relationship between the temperature and the difference between the Hall voltage is recorded, and the Hall voltage at any two aperture diameters is measured. IG meter can be used as a kind of temperature sensor by a simple method by calculating the temperature using the relationship between the difference between the temperature and the temperature.

Also, by using the relationship between the difference between the Hall voltage and the temperature at any two aperture diameters, the amount of change due to the temperature change becomes large, so that the relationship between the Hall voltage and the temperature at a specific aperture diameter is determined. , Temperature detection with high accuracy can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of an entire imaging apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between a difference in Hall voltage and a temperature when the throttle according to the first embodiment is fully opened and fully closed.

FIG. 3 is an explanatory diagram of an operation of the imaging apparatus according to the second embodiment.

FIG. 4 is a program diagram of a second embodiment.

FIG. 5 is an explanatory diagram of an external measurement autofocus device according to a second embodiment.

FIG. 6 is an explanatory diagram of a lens barrel driving device according to a second embodiment.

FIG. 7 is an explanatory diagram of a lens barrel operation according to the second embodiment.

FIG. 8 is an explanatory diagram showing the relationship between the Hall voltage and the aperture diameter at each temperature.

FIG. 9 is a structural explanatory view of a conventional IG meter device.

FIG. 10 is a block diagram of an entire image pickup apparatus in a conventional video camera.

FIG. 11 is a block diagram of an entire conventional imaging apparatus.

[Explanation of symbols]

 Reference Signs List 1 shooting lens 2 CCD 3 aperture blade 4 signal processing circuit 5 aperture drive member 6 aperture drive circuit 8 recording unit 9 CPU 10 changeover switch 11 lens barrel drive circuit 12 temperature sensor 13 lens barrel drive member 14 AF device 17 subject 19 DC motor 20 Pulse sheet 21 Photo interrupter

Claims (8)

[Claims] 1. An image pickup apparatus comprising: a photographing lens; an aperture blade for controlling an amount of photographing light of the imaging lens; a detection unit for detecting an aperture diameter of the aperture blade; and a control unit for controlling an aperture diameter of the aperture blade. An apparatus, wherein the control unit has a storage unit that stores information on a change in a difference in detection output from the detection unit at a plurality of aperture diameters of the aperture blade due to a temperature, and obtains the information at the plurality of aperture diameters. An imaging device configured to calculate an ambient temperature from the difference between the outputs of the detection means and the information stored in the storage means. 2. The imaging apparatus according to claim 1, wherein the control unit controls the aperture diameter of the diaphragm blade in accordance with the calculated temperature. 3. The image pickup unit according to claim 2, further comprising: a photographing lens, an AF unit for automatically adjusting a focus state of the photographing lens to a subject, and an aperture blade and a shutter for controlling a photographing light amount of the photographing lens. Detecting means for detecting the aperture diameter of the aperture blade, and storage means for storing information on a change in the difference between the detection output from the detection means at a plurality of aperture diameters of the aperture blade due to temperature, and Control means for calculating an ambient temperature from a difference between outputs of the detection means obtained in the aperture diameter and information stored in the storage means, and controlling the imaging unit based on the calculation result. An imaging device characterized by the above-mentioned. 4. The imaging apparatus according to claim 3, wherein the control unit controls an aperture diameter of the diaphragm blade according to the calculated temperature. 5. The imaging apparatus according to claim 3, wherein the control unit controls an operation of the shutter according to the calculated temperature. 6. The imaging apparatus according to claim 3, wherein the control unit controls the AF unit according to the calculated temperature. 7. The imaging apparatus according to claim 1, wherein the plurality of aperture diameters of the aperture blade are fully closed and fully open. 8. The device according to claim 1, wherein the detection unit is a Hall element that detects a rotation angle of an IG meter that drives the aperture blade, and the detection output is:
An imaging apparatus, wherein the imaging device is a Hall voltage of the Hall element.