JPH0728121A - Camera system - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] To provide a camera system capable of freely selecting a function for controlling the operation of a camera and selecting the function that suits the photographer's intention. [Arrangement] The accessory is an accessory storage unit P1 that stores the function of controlling the operation of the camera body 30.
To P3, the camera body has control means 33, 34 for controlling the operation of the camera body, and when the accessory is attached to the camera body, the control means is stored in the accessory side storage means. It is characterized in that the camera body is controlled according to the contents.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera system including a camera body and an accessory which can be attached to and detached from the camera body.

[0002]

2. Description of the Related Art A conventional camera controls various operations of the camera according to a stored control program.
For example, a program for focus detection for detecting the in-focus state of the taking lens is stored in the storage unit. 2. Description of the Related Art Conventionally, there is known a camera having a program that obtains data information indicating a luminance distribution of a subject image using an image sensor and processes the data information to perform focus detection.
Hereinafter, a camera having a conventional focus detection program will be described.

FIG. 9 shows an example of the structure of a focus detecting device of this type in a camera. In FIG. 9, reference numeral 1 denotes a single-lens reflex camera, and the light flux from the subject is reflected by the sub-mirror 4 after passing through the taking lens 2 and the half mirror 3, and has a detection surface at a position equivalent to the film surface 5. It is guided to the detection optical system module 6. The focus detection optical system module 6 has, for example, a configuration shown inside a broken line in FIG. In FIG. 10, reference numeral 2 is the same photographing optical system as that shown in FIG. Each of the light fluxes that have respectively passed through the first portion 28 and the second portion 29 of the exit pupil of the photographing optical system 2 is near the planned image forming surface 27 (the surface equivalent to the film surface 5) of the photographing optical system 2. First and second object images are formed, respectively.

Each of the first and second subject images is passed through the field lens 22 and the first and second re-imaging lenses 23 and 24, respectively.
It is re-imaged on 5, 26. Image sensor 25, 26
Is composed of, for example, a CCD or the like, and accumulates charges according to the brightness of the object and outputs a signal relating to the light intensity distribution of the object image on the image sensors 25 and 26.

As described above, the signal relating to the light intensity distribution of the subject image output from the focus detection optical system module 6 in FIG. 9 is A / D converted by the A / D conversion means 8.
The central processing means 9 fetches the subject image data.
The central processing means 9 performs a predetermined focus detection calculation on the captured subject image, and adjusts the focus between the image plane of the photographing optical system 2 and the film surface 5 (undetectable, front focus, rear focus, Information regarding focusing, defocus amount, etc.) is obtained, and in accordance with the information, the display unit 11, the photographing lens driving unit 10, and the auxiliary light unit 12 incorporated in the electronic flash device that can be attached to and detached from the camera (specified when the subject is dark) (For projecting the pattern (1) on the subject) is driven and controlled. The central processing means 9 also controls the charge accumulation of the image sensors 25 and 26.

In the system as described above, the central processing means 9 is composed of a microcomputer or the like, and its operation sequence is a flow chart as shown in FIG. When the power source is turned on and the like, the process starts in step 1, and then in step 2, charge accumulation control of the sensors 25 and 26 is performed. In this case, the central processing means 9 commands the sensors 25 and 26 to start the charge accumulation, terminates the charge accumulation after a time corresponding to the subject brightness, and sweeps out a signal relating to the subject image. Next, in step 3, this signal is A / D converted to 1
It is stored in the memory as the next data. A / D conversion may be performed with any number of bits, but normally about 8 bits is sufficient, and if performed with more bits, it is meaningless considering noise, and memory is wasted wastefully when storing data. Will be done. When the primary data is represented by a pair of (L + 1) pieces of data a (o) to a (L) and a ′ (0) to a ′ (L), for example, FIG. It looks like. However, a '(0) to a' (L) are not shown.

In step 4, these primary data are subjected to an operation as in the following equation, and a pair of (m + 1) secondary data b (0) to b (0) to b as shown in FIG.
(M), b '(0) to b' (m) are created. b (n) =-a (2n) + 2 * a (2n + 2) -a (2n + 4) (1) b '(n) =-a' (2n) + 2 * a '(2n + 2) -a' (2n + 4). ． ． ． ． ． ． ． (1) The purpose of performing calculations such as equation (1) is to remove high-frequency components and low-frequency components contained in the primary data that adversely affect the focus detection calculation, and to perform the focus detection calculation performed in the subsequent steps. This is to reduce the number of data used for and reduce the calculation time.

In step 5, a focus detection calculation is performed using the obtained secondary data to obtain information on the focus adjustment state (focus detection failure, front focus, rear focus, focus, defocus amount, etc.). In step 6, the display unit and the lens driving unit are controlled according to the obtained focus adjustment state (undetectable, front focus, rear focus, focus, etc.).

In step 7, if it cannot be detected, the process proceeds to step 8. If it is not detected, the process returns to step 2 to start the next focus detection operation. In step 8, if there is auxiliary light means, and it is ready, the process proceeds to step 9, and if not, the process returns to step 2. In step 9, the auxiliary light unit is operated to project the auxiliary illumination light or the auxiliary illumination pattern on the undetectable subject prior to the next focus detection operation, and the process returns to step 2 to newly start the next focus detection sequence.

The focus detection calculation in step 5 is performed, for example, by the method described below. First, a pair of (m +
1) Single secondary data b (o) -b (m), b '(o)-
The correlation calculation as follows is performed on b ′ (m), and the correlation amount H (L) is obtained by sequentially changing the shift amount L. Q and r in the equation (2) are constants that define the upper and lower limits of the parameters of the summation operation (Σ).

In FIG. 13 (a), L is given by the equation (2).
6 is a graph when the correlation amount H (L) is obtained while moving from 6 to +6. In the figure, L is a pair of 2 which gives the minimum value of the correlation amount H (L) when L is assumed to be a continuous amount.
It is the relative shift amount of the next data. The relative shift amount L corresponds to the lateral shift amount of the pair of subject images formed on the image sensors 25 and 26 in the direction perpendicular to the optical axis.

Since the correlation value H (L) is discretely obtained for the value of L being an integer, the minimum value of the correlation value H (L) is given by the interpolation method as shown in FIG. 13 (b), for example. The true shift amount Lex is obtained. For example, the slope of the correlation function H (L) on both sides of the shift amount Lex (shown by straight lines L1 and L2)
Are equal, the three points R−1, R, R + 1 near Lex are
Correlation values H (R-1), H at integer shift amounts of
The minimum values Hex and Lex of the correlation function H (L) are obtained from (R) and H (R + 1).

Hex and Lex are calculated by the following equations. In the equation (3), the parameters DL and E represent the quantities shown in FIG. 13 (b) and are calculated by the following equation. When the shift amount Lex is obtained in this way, the defocus amount d (the amount of deviation in the optical axis direction between the image plane of the subject image and the planned image plane) is given by: d = β × Lex (5) Desired. Where β is the image sensor 25,
It is a value determined by the array pitch P of the photoelectric conversion units of 26 and the parameters of the focus detection optical system.

The front focus state and the rear focus state can be detected by the sign of the defocus amount d, and it is determined that the absolute value of the defocus amount d is within a predetermined value, and the in-focus state is detected. The detection that the focus cannot be detected is performed as follows, for example. When the subject has a low contrast, the primary data obtained from the image sensor is also unchanged as shown in FIG.
The secondary data obtained by calculating the next data is also shown in FIG.
As shown in, the overall value becomes small. The correlation amount H (L) obtained by performing the focus detection calculation shown in the equation (2) on such secondary data is as shown in FIG. 13C, and the correlation amount of FIG. Compared with H (L), the level becomes lower, and the minimum value H
Since there is no (R), the shift amount Lex may not be obtained, and in this case, it is determined that detection is impossible.

Further, even when the shift amount Lex is obtained,
It is determined to be undetectable because it contains many errors and lacks reliability. As an example of the determination criteria, in FIG. 13D, it is detected that the value of the parameter E is less than or equal to a predetermined value, or the value Hex / E obtained by normalizing the minimum value Hex with the parameter E is less than or equal to a predetermined value, and detection is impossible. judge.

[0016]

The control by the conventional focus detection program as described above has the following drawbacks. That is, since the focus detection calculation is performed once for the data relating to the subject image obtained by the charge accumulation of the image sensor each time, a subject having a large bias component and a small contrast change component, such as a low contrast subject. Was undetectable.

As described above, a camera having only one focus detection program is very unsatisfactory for a photographer who often shoots a scene in which many unfavorable subjects are present. Also, with conventional cameras, the focus detection program stored in the camera cannot be freely changed, so it is difficult to obtain a photograph that matches the photographer's intention, and it is difficult to take the photograph that the photographer desires. . Further, it is difficult to change the control program when a bug is discovered from the stored control program after the camera is released or when the version is upgraded.

An object of the present invention is to provide a camera system in which the function (control program) for controlling the operation of the camera can be freely selected and the function that suits the photographer's intention can be selected.

[0019]

According to a first aspect of the present invention, in a camera system comprising a camera body and an accessory detachable from the camera body, the accessory stores a function of controlling the operation of the camera body. Equipped with an accessory side storage means, and the camera body,
When the accessory is attached to the camera body, it has a control means for controlling the operation of the camera body,
It is characterized in that the control means controls the camera body according to the contents stored in the accessory storage means.

A second aspect of the present invention is a camera system comprising a camera body and an accessory detachable from the camera body, wherein the accessory is accessory-side storage means for storing a function of controlling the operation of the camera body. The camera body further includes a rewritable camera-side storage unit that stores the function of controlling the operation of the camera body, and a control that controls the operation of the camera body according to the stored contents of the camera-side storage unit. Means, and when the accessory is attached to the camera body, the stored content of the camera side storage means can be rewritten to the stored content of the accessory side storage means.

[0021]

According to the present invention, when an accessory having storage means for storing the function of controlling the operation of the camera body is attached to the camera body, the camera body is controlled by the function stored in the accessory. A function (control program) for controlling the operation of the camera can be freely selected, and the function that suits the photographer's intention can be selected.

[0022]

Embodiments of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram of the camera system of the present embodiment, and FIGS. 2 to 8 are explanatory diagrams of a control program used in the camera system of FIG. This embodiment is realized by a program (software) written in a storage means (ROM) inside or outside the microcomputer.

In FIG. 1, P1, P2 and P3 represent different programs or storage means for storing them. In the camera system shown in FIG. 1A, a plurality of programs P1, P2, P3 are written in the ROM 32 inside the device 30 including the focus detection device, and a plurality of programs P1, P2, P3 are selected by switching the external operation means 31. The program P1, P2, P3 is switched to the program selected by the user.

However, if the structure is such that a plurality of programs P1, P2 and P3 built in the device 30 are switched as described above, the degree of freedom of selection by the photographer is reduced, and a control program suitable for the photographer's intention of photographing is reduced. There is a problem that it is not always possible to select, and when a plurality of programs are built in, the capacity of the storage unit of the device 30 increases, and there is a problem such as an increase in cost.

Therefore, a configuration in which a control program suitable for the photographer's photographing intention can be freely selected will be described below. In the camera system shown in FIG. 1B, the ROM 30 in which the single programs P1 and P2 are written, or the microcomputers 33 and 34 including the ROM, and the device 30 including the focus detection device.
ROM or ROM that has a structure that can be removed and attached so that the user writes a favorite program
Device 3 including a focus detection device including microcomputers 33 and 34 including
By attaching it to 0, the program can be switched.

Instead of the ROM in this embodiment, a rewritable storage means (for example, EPROM) is used, and a program in which a desired program is written externally is attached to the device 30 including the focus detection device to store the program. The selection may be switched. In the embodiment shown in FIG. 1 (c), the storage means shown in FIG. 1 (a) is constituted by a rewritable storage means 35, and the user writes a desired program P1 by an external writing device 36.
By writing P2, it is possible to selectively switch programs.

With the configuration of the embodiment shown in FIGS. 1 (b) and 1 (c), after the device including the focus detecting device is put on the market, the focus detecting device can be disassembled even if a bug is found in the program. It can be modified without modification, and it is easy to upgrade the program and modify it at any time. In the case where peripheral devices controlled by the focus detection device, for example, lens driving means, display means, auxiliary light means, etc. are also configured by a program on the microcomputer, and their operations are controlled by data communication with the microcomputer of the focus detection device. If the program storage means on the peripheral device side is also rewritable or replaceable as in the embodiment of FIGS. 1B and 1C, the focus detection device and the peripheral device are formed. It is easy to deal with the case where a part of the whole system is changed and some programs have to be changed each other.

The structure of the focus detection apparatus having the control program of this embodiment, that is, the focus detection program, which will be described below, is the same as that of FIG. (First Control Program) FIG. 2 shows a first control program of the present embodiment, which starts at step 11,
In step 12, the undetectable flag is initialized to 0. Next, in step 13, the loop counter K is set to 0 and the tertiary data described later is cleared. The undetectable flag is a flag for identifying that the focus detection device is in an undetectable state, and the loop counter K is for counting how many times the central processing means receives the output of the image sensor. It is a counter.

In step 14, the undetectable flag is tested. If the undetectable flag is 1, that is, if it is undetectable, the process proceeds to step 15. If the undetectable flag is 0, that is, if it is detectable, the process proceeds to step 15. Proceed to 17. In step 15, as shown in FIG. 9, since the auxiliary light means is built in the electronic flash device, if the electronic flash device is powered on and the auxiliary light means is ready, step 1
6. If not, proceed to step 17 otherwise.

In step 16, the auxiliary light means is activated,
The auxiliary light is emitted to the undetectable subject. In step 17, charge accumulation control of the sensor is performed. Step 1
In 8, the primary data obtained by A / D converting the signal output from the sensor regarding the light intensity of the subject is stored in the memory.
For example, the primary data is a pair of (L + 1) pieces of data (a
(O) to a (L), a '(o) to a' (L)), and as shown in FIG. 12 (a), the data includes a large amount of change components for a general subject. However, for a low-contrast subject, as shown in FIG. 12C, the data has less contrast change component than the bias component.

In step 19, the primary data (a
From (0) to a (L), a ′ (0) to a ′ (L)), the pair of (m + 1) secondary data (b (o) to b ( m), b '(o) to b' (m)) are created. The secondary data corresponding to the primary data in FIGS. 12 (a) and 12 (c) are as shown in FIGS. 12 (b) and 12 (d), respectively. Is included, and the contrast change component is small for a low-contrast subject.

In step 20, the loop counter K = 0
In the case of, the third-order data and the second-order data are equal, and the pair of (m + 1) third-order data {c (o)
The secondary data {b (o) to b (m), b '(o) to b' (m)} are added to each of ~ c (m), c '(o) to c' (m)}. In step 21, the loop counter K is incremented.

In step 22, the tertiary data {c (o)-
For c (m), c '(o) to c' (m)}, the focus detection calculation as shown in the equations (2) to (5) is performed, and the focus adjustment state (undetectable, front focus, Rear focus, focus, etc.) is detected. If the focus cannot be detected in step 23, the process proceeds to step 25, the undetectable flag is set to 1, and the process proceeds to step 26. If the focus can be detected, the undetectable flag is reset to 0 and the process proceeds to step 27.

In step 26, it is tested whether the loop counter K reaches the maximum count Kmax, and if not, the process returns to step 14 to repeat the next focus detection loop and add the secondary data to the tertiary data ( Called the addition mode). Also, the loop counter K has the maximum count Kma.
If it has reached x, go to step 27. Step 27 is executed when the focus can be detected before the loop counter K reaches Kmax and when the focus cannot be detected even when it reaches Kmax, and the display means, depending on the focus adjustment state,
Controls the lens driving means. Then, returning to step 13, the loop counter K is reset to 0, the tertiary data is cleared, the addition mode is initialized, and the next focus detection sequence is newly repeated.

With the above-described structure, since the third-order data also includes a large amount of contrast change components for a general subject, the loop counter K can be detected at the time of 1 (that is, the first time), and the addition mode can be performed. However, for a low-contrast subject, when the loop counter K is 1, the third-order data has few contrast change components as shown in FIG. Steps 14 through 25 and 26
It will be in addition mode through the route back to. The third-order data is widened every time the addition mode is repeated. For example, at the S-th time, as shown in FIG. 12 (f), the first-order third-order data is increased by about S times to the third-order data. Become. In this way, when the tertiary data is increased in the addition mode, the level becomes the focus detectable level at some number of times, and as a result of the focus detection calculation, it is determined to be detectable, and steps 23 to 24, 27 are performed.
Proceed to and enter the route that returns to step 13 to exit the addition mode.

Therefore, even for a low-contrast object that has been determined to be incapable of focus detection by the conventional focus detection apparatus, the focus detection apparatus of the present embodiment is in the addition mode and the variation component of the tertiary data is increased. Therefore, focus detection becomes possible. Further, even when pattern illumination is performed as auxiliary light, the conventional focus detection device cannot detect because the pattern is buried in the surrounding brightness distribution when the subject has brightness to some extent. The focus can be detected. (Second Control Program) Next, the second control program of this embodiment will be described.

In the first control program, the focus detection calculations (2) to (5) were always performed on the tertiary data, whereas the second control program first performed on the secondary data. The difference is that the focus detection calculation is performed on the tertiary data only when the focus detection cannot be performed as a result. With such a configuration, it is possible to stably and swiftly cope with a sudden shift from the focus undetectable state to the focus detectable state due to the motion of the subject, camera shake, or the like.

The flow of operation of the second control program is shown in FIG. In FIG. 3, steps 61 to 69 are the same as steps 11 to 19 of the first control program in FIG. When the secondary data is obtained in step 69, (2) to the secondary data obtained in step 70
The focus detection calculation of equation (5) is performed to detect the focus adjustment state. That is, the focus adjustment state (undetectable, front focus, rear focus, in-focus) is detected from the information obtained by one-time sensor charge accumulation up to step 70.

In step 71, as a result of step 70,
If the focus cannot be detected, the process proceeds to step 74. Otherwise, in step 72, the undetectable flag is set to 0.
Then, in step 73, the display means and the lens driving means are controlled according to the focus adjustment state, and the process returns to step 63 to start the next focus detection sequence. On the other hand, if the focus cannot be detected, the addition mode is set, and the undetectable flag is set to 1 in step 74.

In step 75, the loop counter K is incremented. In step 76, 2 is added to the tertiary data.
Add the next data. The detailed description of this step is first
Since it is the same as the control program of, the description is omitted. Step 77
Then, if the loop counter K is 1, the process proceeds to step 80, and if it is other than 1, step 78 is executed. That is, at the first time, the secondary data and the tertiary data are the same, and the result of the focus detection calculation is the same as the result executed in step 70.
For the second time, the focus detection calculation for the tertiary data is omitted.

In step 78, the focus detection state shown in equations (2) to (5) is performed on the obtained tertiary data (added secondary data) to detect the focus adjustment state. In step 79, if focus detection is possible with respect to the tertiary data in step 78, the addition mode is exited and step 73 is entered to control the display means and lens drive means in accordance with the focus adjustment state at that time. Return to step 63,
Start the next focus detection sequence. If the focus cannot be detected in step 79, the process proceeds to step 80. In step 80, it is tested whether or not the loop counter K has reached Kmax, and if it has, the exit from the addition mode and the process returns to step 73. If not reached, the process returns to step 64 to repeat the addition mode.

As described above, in the second control program, the focus detection calculation is first performed on the secondary data obtained from the sensor charge accumulation every time, so that it is possible to follow the subject even when the subject suddenly changes, and the response is obtained. The performance is improved and no malfunction occurs. Further, the present invention has the same advantage that the focus detection can be performed by the addition mode even for a low-contrast subject whose focus detection is difficult, as in the first to fourth embodiments. <Third control program> In the first and second control programs, secondary data (or 1
Next data, 1.5th data) was added to the 3rd data. When focus detection became possible, the addition mode was exited and the 3rd data was cleared. With such a configuration, in order to be detected next time, it was necessary to perform addition several times in the addition mode again. In the third control program, in the addition mode, the information (secondary data, primary data, or 1.5th order data) obtained from the image sensor data for the predetermined number of times in the past is stored, and the number of times from the present to the past is stored. Data is added to form third-order data, and focus detection calculation is performed on the obtained third-order data to obtain information regarding the focus adjustment state, so that the responsiveness in the addition mode is enhanced.

FIG. 4 is an operation flow when it is applied to the second control program, and a sequence (step 121 to step 1 in FIG. 4) in the case where detection cannot be made by the focus detection calculation.
34) is the second control program (steps 61 to 7 in FIG. 3).
The description is omitted because it is the same as 3). However, since it is not necessary to clear the tertiary data in the third control program, the loop counter K is reset to 0 in step 123, and if it is determined in step 134 that it can be detected, it is newly updated in step 133. The loop counter K is reset to 0.

Next, the addition mode, which is a feature of the third control program, will be described. When the result of the focus detection calculation for the secondary data obtained in step 131 is determined to be undetectable, the addition mode is entered, and the process proceeds to step 135 to set the undetectable flag to 1. Step 136
Then, it is determined whether or not the loop counter K has reached the predetermined value Kmax, and if not, step 138.
Then, the loop counter K is incremented, the secondary data obtained in step 139 is stored, and step 1
Proceed to 40. The memory for storing the secondary data is shown in FIG.
A memory area M having a predetermined value Kmax as shown in (a) and (b).
(1) to M (Kmax), and the secondary data passes through the routine of step 136 → step 138 → step 139 until the loop counter K reaches Kmax, and the secondary data corresponds to the memory area M ( K).

On the other hand, in step 136, the loop counter K
Has reached Kmax, the routine proceeds to step 137, where there is one (Kmax -1) set of secondary data stored in the memory areas M (2) to M (Kmax) shown in FIG. The memory areas are sequentially shifted one by one and stored again in the memory areas M (1) to M (Kmax -1) shown in FIG. Then, the process proceeds to step 139, and the latest secondary data is stored in the memory area M.
It is stored in (Kmax).

Next, at step 140, the memory area M
The memory area M corresponding to the loop counter K from (1)
The secondary data stored up to (K) are added as in equation (13) to create tertiary data. In the equation (13), c (n) and c '(n) are stored in the tertiary data (where n is 0 to L), and b (n, s) and b' (n, s) are stored in the memory area S. The secondary data is shown.

In step 141, focus detection calculation is performed on the obtained tertiary data to detect the focus adjustment state (non-detectable, front focus, rear focus, focus). Step 14
In step 2, it is judged whether the loop counter K has reached Kmax, and if it has reached Kmax, the process proceeds to step 134, the display / driving means is controlled according to the obtained focus adjustment state, and then the process proceeds to step 124. After that, the sequence is the same as that of the second control program.

If the loop counter K has not reached Kmax in step 142, the process proceeds to step 143 and the display driving is not performed and the process returns to step 124 only when it is determined that detection is impossible. After proceeding to step 134 and controlling the display / driving means, the procedure returns to step 124. In the addition mode of the third control program, since the operation sequence is as described above, even if the loop counter K once reaches the predetermined value Kmax, it is not cleared and returns to 0. Since the tertiary data is created from the secondary data of the past Kmax sets stored in the memory and the focus detection calculation is performed on the tertiary data, the information on the focus adjustment state can be obtained. Can be expected to improve the responsiveness of.

Although the third control program is applied to the second control program in the above description, it goes without saying that the third control program can also be applied to the first and second control programs. In the first to third control programs described above, the maximum value Kmax of the loop counter may be a fixed value or may be changed according to the subject brightness. For example, if the formula (6) is set, the responsiveness does not deteriorate even in the addition mode for a low-luminance subject. Kmax = INTT / Tx (6) In equation (6), INTT is the time corresponding to the subject brightness,
For example, it is the charge storage time of the image sensor, and Tx represents a predetermined time. By doing this, Kmax at low brightness
Is smaller, and you can quickly exit the addition mode.

Further, as a judgment for exiting the addition mode, it is not tested whether the loop counter K has reached Kmax, but information concerning the magnitude of the change component is obtained from the tertiary data in which the change component is increased by the addition. It may be detected and the addition mode may be exited, or may be combined with the determination by the loop counter K. As a method of detecting and determining information from the tertiary data, for example, the following method 1 is available.

If the tertiary data is a pair of (m + 1) pieces of data b (o) to b (m) and b (o) to b (m), (7)
Whether the value of (maximum value-minimum value) of each pair of data exceeds the specified value as shown in the formula, or the absolute value or maximum value of the difference between adjacent data as shown in formula (8) exceeds the specified value. Whether to exit the addition mode depends on whether or not M1 = Max {(b _max −b _min ), (b ′ _max −b ′ _min )} ≧ T1 (7) M2 = Max {| b (n) −b (n + 1) |, | b ′ (n) −b ′ (n + 1) |} ≧ T2 (8) In equations (7) and (8), b _max and b _min are tertiary data b
Maximum and minimum values of (o) to b (m). _b'max , _b'min
Is the maximum and minimum values of the tertiary data b '(o) to b' (m). M
Reference numerals 1 and M2 are information amounts relating to the contrast change component of the tertiary data, and T1 and T2 are reference values thereof. Further, the maximum value Kmax of the loop counter K is calculated by the information amounts M1 and M2 when the loop counter K = 1 and the parameters E obtained by the equation (4) and the reference value T3 for E (9), (10), (1
It may be set as in equation (1). As described above, the decision whether to exit the addition mode is 3
Corresponding to the information parameter E regarding the magnitude of the contrast change component of the next data, the reference value T of the equations (7) to (11)
By appropriately setting 1, T2 and T3, the responsiveness is improved without wastefully repeating the addition mode.

In the first to third control programs, the operation relating to the control of the auxiliary light means, for example, steps 14 to 16 in the first control program are not always necessary and may be omitted. Further, the operation control of the auxiliary light means is not performed every time immediately before the start of image sensor charge accumulation, but 1
Once activated, during some charge storage of the image sensor,
You may comprise so that the same operation may be hold | maintained. Further, the operation of the auxiliary light unit may be related only to the subject brightness when the auxiliary light unit is not operated. <Fourth Control Program> Next, the fourth control program is a case where focus detection is performed using a means for projecting a specific pattern on the subject as auxiliary light means.

When a specific pattern is projected on a low-contrast subject, if the subject brightness is relatively high, the specific pattern is buried in the subject brightness, and focus detection cannot be performed by the conventional focus detection device. . In the fourth control program, the auxiliary light unit is used to convert the primary data obtained from the image sensor when the specific pattern is projected onto the subject, to the primary data obtained from the image sensor when the auxiliary light unit is not used. By subtracting again the primary data, a weak change component due to a specific pattern is detected, and the focus detection is performed after widening it by the addition mode, so even for low contrast patterns of relatively high brightness. The focus can be detected.

The fourth control program can be applied to the above-mentioned first to third control programs. For example, the case of application to the first control program will be described with reference to FIG.
In steps 11 to 13 and steps 19 to 27 are the same as the first control program,
5 are different from each other, only the different portions are shown in FIG. At step 111, the undetectable flag is set to 1 when the addition mode is set, and is set to 0 when the addition mode is not set. Step 1
When the undetectable flag is 0 in 11 and the auxiliary light means is not operated, the process proceeds to step 117. If the undetectable flag is 1, the process proceeds to step 112.

When the auxiliary light means is attached in step 112 and the preparation for operation is completed, step 113
Otherwise, to step 117 otherwise. Step 1
In 13, it is tested whether the loop counter K is 1, and if it is 1, the process proceeds to step 114, and if it is 0, the process proceeds to step 116. In step 114, image sensor charge accumulation control is performed, and in step 115, the image sensor output is A / D converted and the data is converted into a pair of (L + 1) correction data g (o) to g (L), g '(. o) to g ′ (L). Correction data g (o) to g in FIG.
(L) is shown.

Therefore, steps 113, 114 and 115
As correction data when the auxiliary light means is not activated,
The data of the subject image when the loop counter K is 1 will be adopted. In step 116, the auxiliary light means is activated to project the specific pattern on the subject.

In step 117, the image sensor charge accumulation control is performed, and in step 118, the image sensor output is A / D converted and a pair of (L + 1) primary data a.
(O) to a (L) and a '(o) to a' (L) are stored. The primary data a (o) to a (L) is shown in FIG. 7 (b).
Show as. In step 119, if the auxiliary light unit is activated, the process proceeds to step 120, and if it is not activated, the process proceeds to step 19.

In step 120, the correction data of FIG. 7 (a) obtained without operating the auxiliary light means is obtained from the primary data of FIG. 7 (b) obtained by operating the auxiliary light means as shown in equation (12). To another pair of (L + 1) primary data a
(O) to a (L) and a '(o) to a' (L) are obtained. The primary data a (o) thus obtained is shown in FIG. 7 (c).
~ A (L) is shown.

When the primary data is obtained in step 120,
After proceeding to step 19, the sequence is similar to that of the first control program. Therefore, in the case of the addition mode shown in FIG.
When the secondary data is obtained from the primary data shown in (c),
As shown in FIG. 7D, the addition mode is repeated S times 2
The third-order data obtained by adding the next data S times is as shown in FIG. 7E, and the contrast change component of the specific pattern projected on the subject is widened to enable focus detection.

The case where the fourth control program is set to the addition mode and applied to the third control program for adding the primary or (1.5th) data to the tertiary data will be described.
The correction data when the auxiliary light is not activated is shown in FIG.
As shown in FIG. 8A, the primary data when the auxiliary light is activated is as shown in FIG. 8B. The primary data obtained by subtracting the correction data obtained when the auxiliary light is not activated from the primary data obtained when the auxiliary light is activated becomes the primary data again as shown in FIG. 8C.

A pair of (L + 1) third-order data c (o)
.About.c (L) and c '(o) to c' (L) are obtained by adding the primary data, and when S times are added, as shown in FIG.
The variation component corresponds to the specific pattern projected on the object with the increased width. The third-order data obtained in this way is subjected to a calculation such as equation (1) and a pair of (m + 1)
Quaternary data d (o) to d (m), d '(o) to d'
When (m) is obtained, it is at a level at which focus detection can be sufficiently performed. FIG. 8E shows the appearance of the fourth order data.

In the above description of the fourth control program, the correction data g (o) to g (L) and g '(o) to g'.
In (L), the loop data is collected only when the loop counter K is 1, but the correction data may be collected every time when the loop counter K is not 1 and subtracted from the primary data when the auxiliary light is activated. In that case, step 113 is deleted in FIG.

Further, the accumulation times of the image sensors when collecting the correction data are made equal and fixed, or the latter is set a little longer. According to the focus detection device having the control program as described above, only the contrast change component necessary for focus detection is extracted from the subject information obtained from the image sensor, and the information increased by adding it a plurality of times is obtained. I am using it to detect focus, so
There is an advantage that focus detection can be easily performed even for a low-contrast subject, which has conventionally been difficult to detect focus.

In the conventional focus detection device, the focus detection calculation is performed once for each image sensor output, so it is easy to be affected by the random noise in the image sensor output. In the addition mode of the program, since the information obtained from the image sensor is added over a plurality of times, random noise is averaged, so that there is an advantage that it is less likely to be affected by random noise.

[0065]

As described above, according to the first aspect of the present invention, when the accessory having the storage means for storing the function of controlling the operation of the camera body is attached to the camera body, the accessory is stored. Since the camera body is controlled by the function, the function (control program) for controlling the operation of the camera can be freely selected, and the function that suits the photographer's intention can be selected.

Further, according to the second invention, in addition to the effect of the first invention, the function (program) of the operation control built in the camera body is changed to the function (program of the operation control stored in the accessory). ), You can freely select the function that suits the photographer's intention.
Further, there is an advantage that the function can be easily modified and improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a camera system that is an embodiment of the present invention.

FIG. 2 is a flow chart of a first control program of this embodiment.

FIG. 3 is a flowchart of a second control program of this embodiment.

FIG. 4 is a flowchart of a third control program of this embodiment.

FIG. 5 is a flow chart of a fourth control program of this embodiment.

FIG. 6 is a memory map diagram showing a memory area of a storage device of the focus detection device.

FIG. 7 is a diagram showing data information of a subject image detected by an image sensor.

FIG. 8 is a diagram showing data information of a subject image detected by an image sensor.

FIG. 9 is a block diagram of a camera system having a focus detection device.

FIG. 10 is a schematic diagram showing the principle of a focus detection device.

FIG. 11 is a flowchart showing an operation sequence of a conventional focus detection device.

FIG. 12 is a diagram showing data information of a subject image detected by an image sensor.

FIG. 13 is an explanatory diagram illustrating a correlation calculation of the focus detection device.

[Explanation of symbols for main parts]

DESCRIPTION OF SYMBOLS 1 ... Camera 2 ... Shooting lens 3 ... Half mirror 4 ... Sub mirror 5 ... Film surface 6 ... Focus detection optical system module 8 ... A / D conversion means 9 ... Central processing means 10 ... Lens drive means 11 ... Display means 12 ... Auxiliary light means

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03B 17/14 7513-2K

Claims (4)

[Claims] 1. A camera system comprising a camera body and an accessory that is attachable to and detachable from the camera body, wherein the accessory includes accessory-side storage means that stores a function of controlling the operation of the camera body, The camera body has control means for controlling the operation of the camera body, and when the accessory is attached to the camera body, the camera body follows the contents stored in the accessory storage means. A camera system characterized by controlling. 2. The first accessory comprises a first storage means for storing a first function for controlling the operation of the camera body, and a second storage means for storing a second function different from the first function. The camera body is configured to store the first or second accessory in the first or second storage means when the first or second accessory is attached to the camera body. 2. The camera system according to claim 1, wherein the camera body is controlled according to the contents described. 3. A camera system comprising a camera body and an accessory that is attachable to and detachable from the camera body, wherein the accessory includes accessory-side storage means that stores a function of controlling the operation of the camera body, The camera body has a rewritable camera side storage unit that stores a function for controlling the operation of the camera body, and a control unit that controls the operation of the camera body according to the stored contents of the camera side storage unit. A camera system characterized in that, when the accessory is attached to the camera body, the storage content of the camera side storage means can be rewritten to the storage content of the accessory side storage means. 4. The accessory-side storage means stores a first storage unit storing a first function for controlling the operation of the camera body, and a second storage unit storing a second function different from the first function of the first storage unit. Two storage units are provided, and the camera body is configured such that, when the accessory is attached to the camera body, the control unit controls the camera body according to the contents stored in the selected first or second storage unit. 4. The camera system according to claim 3, wherein the camera system is controlled.