JPH09304678A - Image pickup device and video equipment system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an appropriate focus correction by detecting temperature to obtain accurate information on the change of the back focus of an image pickup lens. SOLUTION: In a video camera, a temperature detecting element 25 is arranged on a flexible wiring board 24 to which image pickup elements 21 to 23 such as a CCD, etc., are electrically connected and the information on the change of the back focus of a movable lens group consisting of three lenses 10a, 10b and 10c is obtained by using a detection output signal from the detecting element 25. Based on the information on the change of the back focus, the focus position of the movable lens group is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus and a video equipment system capable of performing stable image pickup without being affected by environmental temperature or internal temperature rise.

[0002]

2. Description of the Related Art In recent years, in the field of image pickup devices such as integrated video cameras (hereinafter simply referred to as video cameras), miniaturization and high functionality have been rapidly advanced, and the influence of temperature on images has become serious. Is coming.

One of them is movement of focus due to temperature. This is because not only the internal temperature rises due to the increase in power consumption due to the miniaturization and higher functionality, but also the focus position accuracy that is allowed as the imaging size becomes smaller, that is, the so-called depth of focus becomes smaller. It has become a more important issue because it greatly affects images.

To solve such a problem, Japanese Patent Laid-Open No. Hei 6 (1994) has heretofore been known.
As disclosed in JP-A-289275, there has been proposed a method of providing a temperature detecting means and sequentially changing and controlling a zoom tracking curve according to an environmental temperature.

[0005]

However, in the conventional device and system as described above, for example, it is important to determine which part in the image pickup device the temperature detecting element is arranged and which part the temperature is detected. The specific contents of the part are not considered, and it is effective when the image sensor is directly attached to the lens barrel, but other than that, for example, a video camera with a color separation prism or an interchangeable lens type video camera. Therefore, accurate temperature compensation was not possible.

The present invention has been made in order to solve such a problem, and is capable of detecting the temperature for obtaining accurate back focus change information and capable of an efficient electrical connection. An object is to provide an apparatus and a video equipment system.

[0007]

An image pickup apparatus according to the present invention is configured as follows.

(1) An image pickup lens and an image pickup device are provided,
A temperature detecting element is arranged on a wiring board on which the image pickup element is mounted, and the focal position of the lens is corrected based on change information of the back focus of the lens obtained using a detection signal of the temperature detecting element. A focus correction means was provided.

(2) In the above apparatus (1), a color separation prism is provided between the lens and the image pickup device.

(3) A lens for image pickup, a prism for color separation, and an image pickup element are provided, a temperature detection element is arranged on the prism, and the back of the lens obtained by using a detection signal of the temperature detection element. A focus correction unit for correcting the focus position of the lens based on the focus change information is provided.

(4) In the apparatus according to any one of (1) to (3) above, the image pickup lens is a variable magnification lens that performs a variable magnification operation, and a correction lens that corrects the displacement of the focal position during the variable magnification. The focus correction means includes a storage means for storing the positional relationship between the variable power lens and the correction lens, and a control means for controlling the movement of the correction lens required by the movement of the variable power lens based on the stored contents. With respect to the zoom tracking control means having the above, the movement control based on the stored contents of the storage means is corrected using the change information of the back focus of the imaging lens as the correction information.

The video equipment system according to the present invention is
It is configured as follows.

(5) An image pickup lens and an image pickup device are provided,
A temperature detecting element is arranged on a wiring board on which the image pickup element is mounted, and the focal position of the lens is corrected based on change information of the back focus of the lens obtained using a detection signal of the temperature detecting element. The image pickup lens further includes a focus correction unit, and the image pickup lens includes a variable power lens that performs a variable power operation and a correction lens that corrects a displacement of a focal position at the time of the variable power. The zoom tracking control means having a storage means for storing the positional relationship between the lens and the correction lens and a control means for controlling the movement of the correction lens required by the movement of the zoom lens based on the stored contents The back focus change information of the camera lens is used as the correction information to correct the movement control based on the stored contents of the storage means, and the image pickup lens is also used. And interchangeable interchangeable lens, the zoom tracking control means provided in the interchangeable lens,
The change information of the back focus is supplied to the interchangeable lens as the change information of the flange back of the image pickup unit, and the interchangeable lens is moved based on the stored change information of the flange back based on the stored content of the storage means. I tried to add a correction to.

(6) In the system of the above (5), a prism for color separation is provided in front of the image pickup device of the image pickup section.

(7) A lens for image pickup, a prism for color separation, and an image pickup element are provided, a temperature detection element is arranged on the prism, and the back of the lens obtained by using a detection signal of the temperature detection element. The image pickup lens is provided with a focus correction unit that corrects the focus position of the lens based on the focus change information, and the imaging lens is a zoom lens that performs a zoom operation and a displacement of the focus position during zooming. The focus correction means has a correction lens for correction, and the focus correction means stores the movement of the correction lens required by the movement of the magnification change lens based on the storage means for storing the positional relationship between the magnification change lens and the correction lens. To the zoom tracking control means having a control means for controlling, the shift information based on the stored contents of the storage means is used as correction information based on the back focus change information of the imaging lens. A correction is added to the control, and the imaging lens is an interchangeable interchangeable lens, the zoom tracking control means is provided on the interchangeable lens side, and the change information of the back focus is the change information of the flange back of the imaging unit. As the above, the interchangeable lens is supplied to the interchangeable lens, and the interchangeable lens corrects the movement control based on the stored contents of the storage means by the supplied change information of the flange back.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. Note that, here, a case of a video camera having an inner focus type lens configuration with an interchangeable lens system having a color separation prism will be described.

(First Embodiment) FIG. 1 is a side sectional view showing the structure of a video camera according to the first embodiment of the present invention.
In the figure, 1 is a video camera body, 2 is a rotatable and detachable bayonet type camera mount fixed to the video camera body 1, and has a flange surface 2a serving as a reference in the optical axis (O-O ') direction. Three mount claws 2b are formed.

Reference numeral 3 is a leaf spring which comes into contact with a mounting claw of a lens mount, which will be described later, and is brought into close contact with the mounting flange surfaces of both the camera mount 2 and the lens mount.
Is a prism holder to which a color separation prism unit to be described later is screwed, 5 is a camera side contact stand, and 6 is an electric movably supported in an optical axis direction OO ′ which is a contact direction with the camera side contact stand 5. This is the contact on the camera side as a static connection terminal.

Reference numeral 7 is a conductive spring for elastically urging the camera side contact 6 in the contact direction, and 8 is a printed circuit board which is electrically connected to the camera side contact 6 via the spring 7, and is located at a position corresponding to the camera side contact 6. The pattern is formed on.

Reference numeral 9 designates a replaceable lens appearance lens barrel, and 10 designates a movable lens group which comprises three lenses 10a, 10b and 10c and is movable in the optical axis direction, for example a focus lens group. Reference numeral 11 denotes a movable lens barrel that holds the movable lens group 10, and 12 denotes a bayonet-type lens mount that is fixed to the external lens barrel 9 of the lens and that is rotatable and detachable. The flange surface 12 a and three reference surfaces in the optical axis direction are provided. Mount claw 12b
Are formed.

Reference numeral 13 denotes a lens side contact block, 14 denotes a lens side contact as an electrical connection terminal fixed to the lens side contact block 13 by insert molding, for example, both mounts 2, 1
It is arranged so as to come into contact with the camera side contact 6 when the rotary mounting of 2 is carried out.

Reference numeral 15 is a protective glass for protecting the movable lens group 10, which is a movable portion, from being directly touched when the interchangeable lens is detached from the video camera body 1, and 16 is a protective glass holder for holding the protective glass 15. .

Reference numeral 17 is an optical low-pass filter for limiting the high frequency component of the light entering the prism, 18, 19, 20
Is a first prism, a second prism, a third prism, 21,
Reference numerals 22 and 23 denote image pickup elements, and 24 denotes image pickup elements 21, 22, 2
3 is a flexible wiring board for electrically connecting 3 and hard board portions 24a, 24b, 24c which are easily soldered to the leads of the image pickup devices 21, 22, 23 and a connecting portion connected to a camera electric board (not shown). It has 24d.

Reference numeral 25 denotes a temperature detecting element mounted on the flexible wiring board 24, and 26 denotes image pickup elements 21 and 2.
It is a shield plate that shields the entire prism unit including 2, 23.

In the configuration of FIG. 1, the movable lens group 10,
The light flux that has passed through the protective glass 15 and the optical low-pass filter 17 is incident on the incident surface 18a of the first prism 18 that is arranged so as to be orthogonal to the optical axis thereof, and is formed on the reflecting surface that forms an inclined surface with the optical axis of the incident light flux. The blue light is reflected by the dichroic layer 18b for reflecting the blue light,
Light of other wavelengths is transmitted.

In the second prism 19, the first prism 18
The light of the wavelength transmitted through is incident on the incident surface 19a, and the red light is reflected by the red light reflection dichroic layer 19b formed on the reflection surface, while the green light is transmitted.

In the third prism 20, the second prism 19
The light in the green range that has passed through is incident on the incident surface 20a and is guided to the image sensor 22 as it is.

The blue region light reflected by the blue region light reflecting dichroic layer 18b of the first prism 18 as described above is totally reflected by the incident surface 18a of the first prism 18,
The light enters the image sensor 23 and forms an image.

Further, the first prism 18 and the second prism 1
An air layer having a uniform thickness of 10 to 30 μm is formed between the first prism 18 and the second prism 18.
The transmission of the transmitted light to the prism 19 is not disturbed at all, and moreover, the dichroic layer 19 of the second prism 19 is provided.
The red light reflected by b can be reliably totally reflected from the incident surface 19a of the second prism 19. Then, the red-colored light that is totally reflected here enters the image pickup device 21 and forms an image.

In this way, the blue region light reflecting dichroic layer 18b of the first prism 18 and the second prism 1 are formed.
Only the green range light that has passed through the red range light reflecting dichroic layer 19b of 9 enters the image sensor 22 and forms an image.

Here, each interchangeable lens is made so that a light beam from a subject is imaged at a predetermined position, and the video camera main body side has a camera mount 2 which is a coupling surface with the interchangeable lens. Based on the flange surface 2a,
The image pickup devices 21 and 2 are always set at a fixed focus position.
It is necessary to arrange 2, 23 imaging planes.

However, when the temperature of the first prism 21, the second prism 22 and the third prism 23 rises due to the rise of the outside air temperature and the temperature rise due to the heat generation inside the video camera body, the first prism 21 and the second prism 21 The prism 22 and the third prism 23 extend in the optical axis direction, and as a result, the image pickup surfaces of the image pickup devices 21, 22, and 23 are placed at positions apart from the focus position.

Therefore, in this embodiment, the first prism 21,
The temperature detection element 25 detects the temperature rise of the second prism 22 and the third prism 23, converts the detection result into the extension amount of the optical path length and transmits it to the interchangeable lens side, and the image forming position on the interchangeable lens side is the video camera. By moving the main body side optical path length (flange back) by the amount of extension, movement of the focus position due to temperature change is corrected.

Therefore, the temperature detecting element 25 needs to detect the temperature change of the first prism 21, the second prism 22 and the third prism 23 which occupy most of the optical path length on the video camera main body side.

In many cases, it is necessary to surround the entire prism unit with a shield plate 26 in order to prevent noise emission from the image pickup devices 21, 22, and 23, which requires high-speed drive pulses. Since the calorific value of a certain component is small, the temperature inside the shield plate 26 is almost uniform everywhere.

Therefore, by the temperature detecting element 25 mounted on the flexible wiring board 24, the first prism 21, the second prism 22 and the third prism 2 can be sufficiently accurately.
It is possible to detect the temperature change of No. 3.

As the temperature detecting element 25, a chip or a lead-shaped diode or the like is usually used, but by arranging it on the flexible wiring board 24, no new member is used for holding and electrical connection, It is quite easy to install and is cost effective.

Next, the electrical circuit configuration of the video camera of this embodiment will be described. FIG. 2 is a block diagram showing the electric circuit configuration of the video camera.

The light flux from the subject is fixed to the first
Lens group 101, a variator lens group 102 that is a second lens group that performs zooming, a diaphragm 103, a fixed third lens group 104, and a focus adjustment function and a movement of a focus surface due to zooming is corrected. Passing through the focus lens group 10, which is the fourth lens group having a competition function,
Of the three primary colors, the red component is the image pickup device 21 such as CCD, the green component is the image pickup device 22 such as CCD, and the blue component is CC.
An image is formed on the image pickup device 23 such as D.

The variator lens group 102 and the focus lens group 10 are an absolute position detecting device 10 such as an encoder.
The absolute positions are detected by 2A and 10A, respectively, and the detection information is supplied to the lens microcomputer 110.

Each image on each image pickup device is photoelectrically converted and amplified by the amplifiers 105, 106 and 107 to the optimum level, and then the camera signal processing circuit 10 is operated.
At the same time it is input to 8 and converted to standard TV signal,
The AF information is read as data by the data reading program 121 of the main body microcomputer 109 as an AF evaluation value.

AF read by the main unit microcomputer 109
Although the evaluation value is not shown, ON / OFF of the AF switch,
It is transferred to the lens microcomputer 110 through the camera side contact 6 and the lens side contact 14 together with the information of the camera side switch such as the zoom lens state.

In the lens microcomputer 110, information from the main body microcomputer 109 is used to drive the variator lens group 102 in the tele or wide pressing direction when the zoom switch is pressed.
2 to drive the variator lens group 102 via the zoom motor 111, and at the same time, the lens cam data 125 previously stored in the lens microcomputer 110.
Based on the above, a signal is sent to the focus motor driver 114 using the program of the control unit 124, and the focus lens group 10 is moved via the focus motor 113, so that the zooming operation without focus movement is performed.

As in the present embodiment, in the type in which the correction lens (focus lens) is located behind the variable power lens (variator lens) on the optical axis, the correction lens in the state in which the focus is maintained at the time of variable power is maintained. The control position changes depending on the subject distance, and the lens cam data 125 is, as shown in FIG. 3A, for each of a plurality of absolute positions of the variator lens group 102 and for each absolute position of the subject distance ( For example, the position of the focus lens group 10 is stored every 1 m and 2 m in FIG. 3A, and the program of the control unit 124 is a program of the control unit 124. The variator lens group 102 and the focus lens group 10 detected by the position detection devices 102A and 10A. The rotation direction and rotation speed of the focus motor 113 are determined by using the lens cam data selected based on the absolute position information.

When the AF switch on the camera body side is ON, the AF control section 123 in the lens microcomputer 110 is controlled via the control section 124 and the motor control section 126 so that the AF evaluation value from the body microcomputer 109 becomes maximum. By sending a signal to the focus motor driver 114 and moving only the focus lens group 10, the automatic focus adjustment operation is performed.

Here, with respect to the driving of the correction lens based on the lens cam data as described above, the origin for securing an accurate back focus (hereinafter referred to as BF) must be determined. The origin is determined by correcting the set reference position with a predetermined correction value.

The predetermined correction value referred to here is the correction value that the lens unit (interchangeable lens) itself has,
The total correction value transmitted from the camera body.The correction value that the lens unit itself has is a fixed value due to variations that occur during the manufacturing of the lens unit, and the temperature change on the lens side. It is the total value of variables that are caused by the above.

The correction value transmitted from the camera body is a variable value due to a temperature change on the camera body side, and is obtained using the detection output signal of the temperature detecting element on the camera body side. It is a value given as change information of the side flange back (hereinafter referred to as FB).

Next, the operation from the temperature detection on the camera body side to the transmission of the correction value to the interchangeable lens side will be described.

The environmental temperature change around the camera body and the temperature rise in the camera body are measured by the temperature detecting element 25 and converted into FB change data by the operation program of the temperature compensation control unit 122 in the body microcomputer 109. This information is transmitted from the main body microcomputer 109 to the lens microcomputer 110, and the control unit 124 in the lens microcomputer 110 performs a predetermined process as a correction value.

Next, how the above-mentioned correction data is used in the lens movement control process will be described.

The lens microcomputer 110 stores lens cam data 125 as an ideal value (design value) as shown in FIG. Then, the following calculation for correction is applied to this. That is, if the correction value transmitted from the camera body side is positive, the BF is longer than the ideal value, so as shown in FIG. 3B, the lens shown by the dotted line with this portion subtracted. Perform parallel shift (downward) to read the cam data. By performing lens movement control using the new data that has been read, accurate zooming that does not cause blurring can be performed.

At this time, if the correction value is negative, it means that BF has shrunk from the ideal value, and the lens cam data is shifted upward and read again.

The processing of the correction value on the interchangeable lens side will be omitted here, but the same processing as described above will be applied to the value caused by the temperature change.

(Second Embodiment) FIG. 4 is a side sectional view showing the structure of a video camera according to the second embodiment of the present invention.
In the figure, 1 to 25 are the same as those in FIG. 1, and thus the detailed description will not be repeated.

The lens group 10 to the prism 1 in FIG.
8, 19, 20 and the configuration of the image pickup elements 21, 22, 23, the mounts of both the interchangeable lens side camera and the camera, which are the attachment / detachment mechanisms of the interchangeable lens side and the camera body side, and the contact structure are exactly the same as those in FIG. . Further, since the electric circuit configuration and the operating principle are the same, the description is omitted here.

In FIG. 4, the temperature of the first prism 21, the second prism 22 and the third prism 23, which fluctuates due to the rise of the outside air temperature and the temperature rise due to the heat generation inside the video camera body, is detected by the temperature detecting element 25. , Is transmitted to a camera electric board (not shown).

In this embodiment, it is assumed that there is no shield plate that surrounds the entire prism unit. In this case, however, the temperature surrounding the prism unit has a certain temperature difference depending on the location. Mounting on the flexible wiring board 24 is not appropriate.

In such a case, the first prism 21,
It is necessary to directly attach the temperature detecting element 25 to either the second prism 22 or the third prism 23.

In the present embodiment, the temperature detecting element 25 is attached to the third prism 23, which makes it possible to detect an accurate temperature change of the prism, and an accurate change of the optical path length (FB) on the video camera body side. The amount can be transmitted to the lens side microcomputer, and the movement of the focus position due to the temperature change can be accurately corrected.

[0061]

As described above, according to the present invention,
In each form of a device such as a video camera, it is possible to provide an imaging device and a video equipment system capable of detecting a temperature for obtaining accurate back focus change information and enabling efficient electrical connection. There is an effect.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a configuration of a video camera according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an electric circuit configuration of a video camera.

FIG. 3 is an explanatory diagram showing a relationship between a zoom lens position and a correction lens position.

FIG. 4 is a side sectional view showing a configuration of a video camera according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Video camera main body 2 Camera mount 3 Leaf spring 4 Prism holder 5 Camera side contact block 6 Camera side contact 7 Spring 8 Printed circuit board 9 External lens barrel 10 Movable lens group 11 Moving lens barrel 12 Lens mount 13 Lens side contact block 14 Lens-side contact 15 Protective glass 16 Protective glass holder 17 Optical low-pass filter 18, 19, 20 Prism 21, 22, 23 Image sensor 24 Flexible wiring board 25 Temperature detection element 26 Shield plate 102 Variator lens group 105, 106, 107 Amplifier 108 Camera signal processing circuit 109 Main body microcomputer 110 Lens microcomputer 111,113 Motor 112,114 Motor driver

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location G03B 3/00 A

Claims (7)

[Claims] 1. A back focus of the lens, which comprises an image pickup lens and an image pickup element, arranges a temperature detection element on a wiring board on which the image pickup element is mounted, and uses a detection signal of the temperature detection element. An image pickup apparatus comprising: a focus correction unit that corrects the focal position of the lens based on the change information. 2. The image pickup apparatus according to claim 1, further comprising a prism for color separation between the lens and the image pickup element. 3. A back focus of the lens, which comprises an image pickup lens, a color separation prism, and an image pickup element, a temperature detection element is arranged on the prism, and a detection signal of the temperature detection element is used to obtain the backfocus. An image pickup apparatus comprising: a focus correction unit that corrects the focal position of the lens based on the change information. 4. An image pickup lens has a variable power lens for performing a variable power operation and a correction lens for correcting displacement of a focal position at the time of variable power, and the focus correction means corrects the variable power lens and the correction lens. The zoom tracking control means having a storage means for storing the positional relationship of the lenses and a control means for controlling the movement of the correction lens required by the movement of the variable power lens based on the stored contents 4. The image pickup apparatus according to claim 1, wherein the back focus change information is used as correction information to correct the movement control based on the storage content of the storage unit. 5. A back focus of the lens, which comprises an image pickup lens and an image pickup element, arranges a temperature detection element on a wiring board on which the image pickup element is mounted, and obtains a detection signal of the temperature detection element. Focus correction means for correcting the focal position of the lens based on change information of
Further, the image pickup lens has a variable power lens that performs a variable power operation and a correction lens that corrects the displacement of the focal position at the time of variable power, and the focus correction means positions the variable power lens and the correction lens. The back focus of the lens for imaging is provided to the zoom tracking control means having a storage means for storing the relationship and a control means for controlling the movement of the correction lens required by the movement of the zoom lens based on the stored content. Change information is used as correction information to correct the movement control based on the stored contents of the storage means, and the imaging lens is an interchangeable lens, and the zoom tracking control means is provided on the interchangeable lens side. And providing the change information of the back focus to the interchangeable lens as change information of the flange back of the imaging unit, and the interchangeable lens. Video device system characterized by adding the correction to the movement control based on the stored contents of said memory means by the change information of the supplied flange back. 6. The video equipment system according to claim 5, wherein a prism for color separation is provided in front of the image pickup device of the image pickup unit. 7. A back focus of the lens, which comprises an image pickup lens, a color separation prism, and an image pickup element, a temperature detection element is arranged on the prism, and a detection signal of the temperature detection element is used. A focus correction unit that corrects the focus position of the lens based on the change information of the lens, and the imaging lens corrects the displacement of the focus position at the time of zooming and the zooming lens that performs the zooming operation. The focus correction means controls the movement of the correction lens required by the movement of the zoom lens based on the storage means for storing the positional relationship between the zoom lens and the correction lens and the stored contents. To the zoom tracking control means having a control means for controlling movement of the back focus of the imaging lens as correction information based on the stored contents of the storage means. In addition, the lens for image pickup is an interchangeable interchangeable lens, and the zoom tracking control means is provided on the interchangeable lens side,
The change information of the back focus is supplied to the interchangeable lens as the change information of the flange back of the image pickup unit, and the interchangeable lens is moved based on the stored change information of the flange back based on the stored content of the storage means. A video equipment system characterized by the addition of corrections.