JP4663246B2 - Camera, camera system and lens apparatus - Google Patents

Description

The present invention relates to a camera to which a plurality of photographing lenses are selectively attached and a lens device to be attached to the plurality of cameras .

  For example, Patent Document 1 discloses a technique for preliminarily storing adjustment values for causing each apparatus to perform a predetermined operation in an automatic focus adjustment apparatus, an automatic exposure apparatus, or the like of a camera. That is, in Patent Document 1, an adjustment program for an automatic exposure device is built in a camera, and when a calibration signal indicating that the camera is in a calibration process is added, the camera detects individual differences between products, A method for executing an adjustment operation by writing an adjustment value corresponding to the operation characteristic in a nonvolatile memory is disclosed.

  This is because individual differences of each product caused by tolerances of parts used during production are detected in the calibration process, and adjustment values according to individual operation characteristics are stored in advance at the time of shipment from the factory. It is intended to perform an appropriate operation.

Patent Document 2 discloses a first storage unit that stores the adjustment value set in the calibration step, and a second storage unit that stores a correction value for correcting the adjustment value stored in the first storage unit. The adjustment value set in the calibration process at the time of factory shipment can be freely corrected by the user by the changing means that changes the correction value stored in the second storage means in accordance with the user's intention, and is free Discloses an automatic focus adjustment device, an automatic exposure device, and the like that can be reset to factory settings.
Japanese Patent Publication No.7-117677 (paragraph numbers 0030 and 0031) JP 2001-174690 A (paragraph number 0039)

  However, when considering an automatic focusing device for an interchangeable lens type camera that is selectively mounted on a plurality of lenses having different types of functions, the same correction is applied to all the mounted interchangeable lenses. . For example, when a plurality of photographing lenses made of the same model are attached to a camera, the same correction is applied to all the photographing lenses.

Indeed, the interchangeable lens tolerances of all mounted is sufficiently small, if there fair need a camera, it is possible to solve the problem in this way. On the other hand, if there is a fair need for the interchangeable lens to be mounted, conventionally, the interchangeable lens has been calibrated.

If is sufficiently small tolerances of the interchangeable lens both the camera, also in the prior art described above, there is no need for calibration in a general practice. It wants only die in a very large need some special shooting stretch as commercial photographic, more accurate focusing accuracy is required. The thus if you want is a tuning tolerances occurring only when combined with certain of the interchangeable lens and a specific camera yet to be taken into account.

In other words, for example, even with interchangeable lenses of the same model, the mounting angle with respect to the mount provided on the front surface of the camera body varies depending on each interchangeable lens. small tolerances caused by the mounting angle difference we must also take the.

In order to solve the above-described problem, the camera of the present invention is a plurality of photographing lenses capable of focus control, and individual information assigned to each photographing lens to identify each photographing lens as one individual Focus detection for obtaining first information used for focus control of a photographic lens using a light beam from the photographic lens attached to the camera. Means and information for correcting the first information, the second information corresponding to the camera and the photographic lens attached to the camera is associated with the individual information assigned to the photographic lens. Information for correcting the first information, the memory storing the third information obtained by attaching the reference lens to the camera, and the first information is corrected. And each photographic lens is information for correcting the first information, and stores fourth information obtained by mounting each photographic lens on a reference camera. The correcting means acquires the individual information and the fourth information from the photographic lens attached to the camera, and if the individual information acquired from the photographic lens is not stored in the camera, the correcting means stores the first information stored in the memory. When the first information is corrected using the information 3 and the fourth information acquired from the photographing lens and the individual information acquired from the photographing lens is stored in the camera, the first information is stored in the memory. The first information is corrected using the third information and the fourth information acquired from the photographing lens, and the corrected result is stored in the memory in association with the individual information. It is characterized by correcting using.

According to the present invention, when the individual information assigned to the mounted photographing lens is stored in the camera, the first information used for focus control of the photographing lens is obtained using the reference lens or the reference camera. corrected using the third information and the fourth information which is further the result of the correction, (stored in the memory in association with the individual information) corresponding to the camera and the photographing lens second it is possible to provide a compensation camera capable using information. Thus, even when a plurality of photographing lenses having different individual information are selectively attached to the camera, the first information for each photographing lens attached to the camera can be corrected, so that focus control can be performed. It is possible to improve the accuracy of the. In addition, even when individual information is not stored in the camera, focus control can be performed by correcting the first information using the third information and the fourth information.

Embodiment 1 of the present invention will be described below.

FIG. 1 is a functional block diagram of a camera system that is an embodiment of the present invention. In the figure, 1 denotes a camera, the center front of the camera 1 via the mount 1a shown by a dotted line, zooming capable lens barrel 3 is mounted.

  First, the configuration of the lens barrel 3 will be described. 11 is a lens MPU (microprocessing unit), 12 is a lens driving unit for driving the photographing lens in the optical axis direction, and 13 is an aperture driving unit for driving the aperture blades to open and close in the plane orthogonal to the optical axis. In FIG. 1, a solid line connecting the blocks indicates an electrical connection, and a dashed line indicates a mechanical connection.

  Reference numeral 14 denotes a first storage unit, which is configured by an EEPROM (Electronically Erasable and Programmable Read Only Memory) as an electrically rewritable nonvolatile memory. The first storage unit 14 stores a correction amount (fourth information) obtained by attaching the lens barrel 3 to a reference camera (to be described later). Details will be described later.

  Reference numeral 15 denotes individual information assigned to each photographing lens as an individual. In this embodiment, individual information is obtained by using a model number for identifying the model of the photographing lens and a manufacturing number for each photographing lens. However, as long as it is individual information that can identify the photographing lens as one individual, for example, a series of serial manufacturing numbers exceeding the model without using the model number, or a non-overlapping number such as a channel may be used.

  Next, the configuration of the camera 1 will be described. A camera MPU 21 can communicate with the lens MPU 11. The camera MPU 21 can acquire the correction amount stored in the first storage unit 14 and the individual information 15 of the photographic lens attached to the camera 1 from the lens MPU 11.

Reference numeral 22 denotes a defocus amount detection unit that detects a defocus amount (first information) used for focus control of the photographic lens using a light beam from the photographic lens, and reference numeral 23 denotes a shutter drive unit.

Reference numeral 24 denotes an image sensor (for example, a CCD or CMOS image sensor) that photoelectrically converts a light beam from the photographing lens to generate an image signal. Reference numeral 25 denotes a dial unit for setting various settings of the camera (shutter speed, aperture value, photographing mode, etc.).

Reference numeral 26 denotes a second storage unit (memory), which is configured by an EEPROM (electrically erasable and programmable read-only memory) as an electrically rewritable nonvolatile memory. In the second storage unit 26, a correction amount (third information) obtained by mounting a later-described reference lens (specific lens) on the camera 1 and a plurality of photographings that are selectively mounted on the camera 1. The lens individual information and the correction amount (second information) associated with each individual information are stored.

That is, in the second storage unit 26, the individual information A and the correction amount associated with the individual information A, the individual information B, the correction amount associated with the individual information B,..., The individual information N Like the correction amount associated with the individual information N, there are correction amounts corresponding to a plurality of photographing lenses that can be attached to the camera 1 (in other words , corresponding to the camera 1 and the photographing lens attached thereto). It is remembered.

  SW1 is a switch that is turned on when a release button (not shown) is operated by a first stroke (half press), and SW2 is a switch that is turned on when a release button (not shown) is operated by a second stroke (full press). is there.

  When SW1 is turned on, the defocus amount detection unit 22 is driven, and a focus detection operation is started. When SW2 is turned on, exposure to the image sensor 24 and recording of an image signal photoelectrically converted by the image sensor 24 onto a recording medium (not shown) are started.

The amount of defocus required for automatic focus adjustment (the difference between the imaging lens imaging position and the imaging lens image plane position on which the imaging operation should be performed) is a subject that passes through two different areas across the optical axis of the imaging lens. calculated image shift amount or these two images formed respectively by the light beam.

  Specifically, the light fluxes of these two images pass through a main mirror that is obliquely disposed in a photographing optical path that is a half mirror, and are reflected below the camera 1 by a sub mirror disposed on the image plane side of the main mirror. Then, it is guided to the defocus amount detection unit 22 by a focus detection optical system (not shown).

  The defocus amount detection unit 22 is a photoelectric conversion element, and the camera MPU 21 reads the signals of these two images, calculates the image shift amount by performing a correlation operation, and obtains the defocus amount.

Although automatic focusing is performed in this way, first, the photographic lens has a different photographic optical system, so even if there is a subject at the position of the just focus, depending on the lens model, defocusing may occur. The amount is not zero. Further, even if the defocus amount of the design is 0, the tolerances of the photographing optical system, not necessarily the defocus amounts of all the individual lenses is zero.

Therefore, in the lens calibration process at the factory, the defocus amount is measured with a reference camera (specific camera) adjusted in advance in a state where the light receiving surface of the image sensor 24 is in focus. The defocus amount is stored in the first storage unit 14 of the lens barrel 3 as the correction amount as described above.

In actual operation, at the time of automatic focus adjustment , the camera MPU 21 as the correction unit communicates with the lens MPU 11 to acquire the correction amount stored in the first storage unit 14 by communication and is detected by the defocus amount detection unit 22. This correction amount is subtracted from the defocus amount.

  In addition, the defocus amount is not always 0 for all cameras even if the subject is in the just focus position due to the tolerance of the focus detection optical system. Therefore, in the camera calibration process at the factory, the defocus amount is measured with a reference lens that has been adjusted in advance in a state where the light receiving surface of the image sensor 24 is in focus. The defocus amount is stored in the second storage unit 26 of the camera 1 as the correction amount as described above.

  Specifically, first, the flange back of the camera (the distance from the photographing lens to the light receiving surface of the image sensor 24) is measured to determine the amount of deviation from the design value. Next, the reference lens that has been previously focused on the reference chart at a known distance is corrected by the amount of deviation of the flange back. Subsequently, the reference chart is placed at the center of the sensor, the defocus amount is measured, and the defocus amount is written in the second storage unit 26 as a correction amount.

  In actual operation, during automatic focus adjustment, the camera MPU 21 reads the correction amount stored in the second storage unit 26 and subtracts this correction value from the defocus amount detected by the defocus amount detection unit 22. .

  Next, a method for correcting the defocus amount of the camera system of the present embodiment will be described with reference to the flowchart of FIG.

First, in step S101, the camera MPU 6 reads the subject image from the defocus amount detection unit 22 and calculates the defocus amount. As method of detecting a defocus amount, in the present embodiment, using the phase difference detection method, it may be used TV-AF scheme.

Next, in step S102, the camera MPU 21 reads the correction amount (third information) obtained using the reference lens from the second storage unit 26, and corrects the defocus amount obtained in step S101. To do.

Subsequently, in step S103, the camera MPU 21 reads the correction amount (fourth information) obtained by using the reference camera stored in the first storage unit 14 by communicating with the lens MPU 11, and step S103 is performed. The corrected defocus amount obtained in S102 is corrected.

In step S <b> 104, the camera MPU 22 communicates with the lens MPU 11 to read the individual information 15 and determines whether the individual information 15 is stored in the second storage unit 26 of the camera 1.
If stored, the process proceeds to step S105, and the correction amount (second information) stored in association with (corresponding to) the individual information is read from the second storage unit 26 and obtained in step S103. Correct the defocus amount.

Thus, the defocus amount obtained by the defocus amount detection unit 22 is stored in the second storage unit 26 and the correction amount obtained using the reference camera stored in the first storage unit 14. After correcting with the correction amount obtained using the reference lens, this correction result is further corrected with the correction amount according to the individual information assigned to each individual photographing lens, so the model is the same. Even when a plurality of photographing lenses are selectively attached to the camera, correction according to the attached photographing lens ( according to the camera and the photographing lens attached thereto) can be performed. Thereby, the focus accuracy of the lens can be improved.
On the other hand, if not stored, the process proceeds to step S106 without correction depending on the correction amount stored in association with the individual information, and the defocus amount correction processing is terminated.

FIG. 3 is a functional block diagram of the camera system according to the second embodiment as a reference technical example of the present invention . The same components as those of the first embodiment are denoted by the same reference numerals and the description thereof is omitted.

Unlike the first embodiment, the camera system according to the present embodiment corrects the defocus amount by the lens MPU 11 as the correction unit using the individual information of the camera.

  Reference numeral 27 denotes individual information assigned to each individual camera. In this embodiment, individual information is obtained using a camera model number that identifies the camera model and a camera manufacturing number that identifies each camera belonging to the camera model number. It is said. As in the first embodiment, any information may be used as long as it can identify a camera as an individual.

In the first storage unit 14 of the lens barrel 3, the correction amount (fourth information) obtained by attaching the lens barrel 3 to the reference camera and the individual camera to which the lens barrel 3 can be attached. Information and a correction amount (second information) associated with the individual information are stored. The second storage unit 26 of the camera 1 stores a correction amount (third information) obtained by attaching the reference lens to the camera 1.

  Next, a method for correcting the defocus amount of the camera system of this embodiment will be described.

First, the lens MPU 11 reads a subject image from the defocus amount detection unit 22 and calculates a defocus amount (first information) . As method of detecting a defocus amount, in the present embodiment, using the phase difference detection method, it may be used TV-AF scheme.

Then, the correction amount obtained using the reference lens is read from the second storage unit 26, and the above-described defocus amount detected by the defocus amount detection unit 22 is corrected. Compensation method so far are the same as in Example 1.

  Next, the corrected defocus amount is further corrected according to the flow shown in FIG. That is, in step S201, the lens MPU 11 reads out the correction amount obtained using the reference camera stored in the first storage unit 14, and in step S202, the read correction amount is transmitted by communication. get. At this time, the process of correcting the defocus amount after correction using the correction amount acquired by this communication is not performed, and the process proceeds to step S203.

  In step S <b> 203, the lens MPU 11 reads the individual information 27 by communicating with the camera MPU 21, and determines whether the individual information 27 is stored in the first storage unit 14. If the individual information 27 is stored in the first storage unit 14, the process proceeds to step S 204, and the correction amount stored in association with the individual information 27 is read from the first storage unit 14, and is read in step S 202. Is added to the correction amount obtained in (1). Thereby, the same effect as Example 1 can be acquired.

On the other hand, if not stored , the process proceeds to step S205 without adding any correction amount stored in association with the individual information 27, and the defocus amount is corrected by the correction amount acquired in step S202. To do.

FIG. 2 is a functional block diagram of the camera system according to the first embodiment. 6 is a flowchart illustrating a procedure for correcting a defocus amount of the camera system according to the first exemplary embodiment. 6 is a functional block diagram of a camera system according to Embodiment 2. FIG. 10 is a flowchart illustrating a procedure for correcting a defocus amount of the camera system according to the second embodiment.

Explanation of symbols

11 Lens MPU
12 Lens drive unit 13 Aperture drive unit 14 First storage unit 15 27 Individual information 21 Camera MPU
22 Defocus amount detection unit 23 Shutter drive unit 24 Image sensor 25 Dial unit 26 Second storage unit

Claims (4)

A plurality of photographic lenses capable of focus control, wherein a plurality of photographic lenses having individual information assigned to each photographic lens in order to identify each photographic lens as one individual is selectively mounted There,
Focus detection means for obtaining first information used for the focus control of the photographic lens using a light beam from the photographic lens mounted on the camera;
Information for correcting the first information, wherein the second information corresponding to the camera and the photographing lens attached to the camera is associated with the individual information assigned to the photographing lens. A memory for storing the third information, which is information for correcting the first information and obtained by attaching a reference lens to the camera;
Correction means for correcting the first information,
Each photographing lens is information for correcting the first information, and stores fourth information obtained by mounting each photographing lens on a reference camera.
The correction means includes
Obtaining the individual information and the fourth information from the photographic lens mounted on the camera;
When the individual information acquired from the photographing lens is not stored in the camera, the third information stored in the memory and the fourth information acquired from the photographing lens are used. 1 information is corrected,
When the individual information acquired from the photographic lens is stored in the camera, the first information is obtained using the third information stored in the memory and the fourth information acquired from the photographic lens. camera corrects the information, further the result of the correction, characterized in that in association with the individual information is corrected by using the second information stored in the memory.   The camera according to claim 1, wherein the individual information is different from each other even when the plurality of photographing lenses are of the same model.   The camera according to claim 2, wherein the individual information includes at least a serial number. A taking lens,
A camera system comprising: the camera according to claim 1 to which the photographing lens is attached.

Images