JP2621304B2 - Camera system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera system that performs predetermined control based on lens data stored in a lens and lens data stored in a camera body.

(Prior Art) With increasing functionality of cameras, lens data required for control on the camera body side is increasing. Conventionally, only data transmission by functional coupling between a lens and a body, which has been general, limits the type and accuracy of data that can be transmitted from the lens side to the camera body side.
Therefore, it is already known that a ROM (read only memory) storing lens-specific lens data is stored in the lens, and the lens data is electrically transmitted between the lens and the body.

Also, an electric signal unique to the lens is stored in each lens, lens data unique to each lens is stored in the body, and stored in the body based on the electric signal transmitted from the lens. A camera capable of performing exposure control by selecting lens data of the lens is disclosed in West German Patent No. 3518887.

(Problems to be Solved by the Invention) However, when the camera has more functions and the lens data required for control in the camera body further increases, only the lens data necessary for the function of the conventional camera is stored. With a conventional lens equipped with ROM, even if there is consistency of the mount that guarantees data transmission between the lens and the new camera body, if the conventional lens is mounted on the new body, the newly added function The camera body cannot be performed.

When the camera body stores unique lens data for each lens, such a problem does not occur. However, since the unique lens data must be stored for each lens, Will store a huge amount of data, which is not practical.

Therefore, an object of the present invention is to provide a camera system that can execute a new function using a conventional lens even when the camera body acquires a new function.

(Means for Solving the Problems) In order to achieve the above object, a camera system according to the present invention provides a lens group that belongs to a first lens group among first and second predetermined lens groups. A first lens group having identification data, type determination data indicating the type of lens, and first lens data unique to the lens necessary for the camera system to perform a predetermined first function; and Lens group identification data indicating belonging to the lens group;
Lens data and the lens-specific second data required for the camera system to perform a new second function not included in the first function.
A second lens group having the following lens data, and a camera body. The camera body includes a storage unit that stores the second lens data for the first lens group, a determination unit that determines which lens group the attached lens belongs to, and a determination unit based on a result of the determination unit. And control means for performing predetermined control.

(Operation) According to the above configuration, the determination unit determines which lens group the lens belongs to based on the lens group identification data of the attached lens, and based on the result, the control unit determines the first group. When a lens belonging to the lens group is mounted, both the first lens data stored in the lens and the second lens data stored in the camera body specified by the type determination data are stored. Based on the predetermined control, based on the first and second lens data stored in the second lens group, when a lens belonging to the second lens group is mounted, the predetermined control is performed. .

That is, even when a lens belonging to the first lens group, which does not have the second lens data necessary for performing the second function, is attached to the second lens group, the second lens corresponding to the type of the lens is attached. Since the data is stored in the camera body, it does not prevent the system from performing the second function.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the overall circuit configuration of one embodiment of the present invention. In FIG. 1, contact groups (711) to (715) provided on a mount (7) are provided between a circuit ( 1 ) in the camera body and a circuit ( 6 ) in the taking lens.
They are electrically connected by (721) to (725).

(100) is a control circuit for controlling this system (hereinafter referred to as a control CPU).
It operates under the direction of PU (100). (1
0) is the control CPU (100) and the circuit in the taking lens ( 6 )
Power supply for supplying a constant voltage to the

Reference numeral 310 denotes a photometric circuit, which is a photometric photoelectric conversion amount (equivalent to a subject luminance value) by a photometric element (not shown) that performs TTL photometry.
A / D-converts the information about subject brightness BV (to be exact, BV
−AVo: AVo is the control CPU as the release aperture of the taking lens)
Send to (100).

An exposure control circuit (320) controls an aperture mechanism (not shown) of the photographing lens and a shutter mechanism (not shown) of the camera based on a command from the control CPU (100).

A focus detection / control circuit (330) includes a focus detection circuit (not shown) and a lens drive control circuit (not shown).

Reference numeral 340 denotes a display circuit for displaying photographing information such as an exposure mode of the camera, an exposure control value (aperture value and shutter speed value), a frame counter value, and focus / non-focus.

An auxiliary light circuit (350) is turned on when focus detection is not possible under visible light. The auxiliary light circuit built into the camera body has already been filed by the present applicant in Japanese Patent Application No.
As filed in 141538.

(360) is a film sensitivity information circuit, which is read from the film cartridge of the film loaded in the camera.
Controls film sensitivity information based on DX code.
Send to 0).

(112) is a switch (SW1) which is closed by pressing a release button (not shown) to the first stage, and (114) is a switch which is closed by pressing the release button further deeper than the first stage to the second stage. The switch (SW2) to be formed.

The oscillation circuit (370) supplies a pulse to the control CPU (100).

Next, the mounting section (7) will be described. The mount section (7) includes a camera body side mount (71) and a photographing lens side mount (72). In this embodiment, five pairs of electrical contacts (711) to (715) and (721) to (721) are provided. 725) is provided so that serial communication can be performed between the camera body and the lens by the circuit connection described below. The control CPU (100) in the camera body drives the serial output clock output terminal Sck (102), the input terminal Sin (103) that reads input data from the lens serially, and the driving lens internal circuit ( 6 ). , The contact (712) of the body side mount part is connected to the clock output terminal Sck (102), the mount contact (713) is connected to the input terminal Sin (103), and the mount contact ( 7
14) are connected to the output terminals CS (104), respectively.

The contact (711) is connected to the power supply (10) via a short-circuit protection resistor (14), and the mounting contact (715)
Is grounded to the ground line of the circuit ( 1 ) in the camera body.

Now, it is assumed that the photographing lens is a zoom lens. The zoom encoder (61) encodes a signal △ Z corresponding to a zoom operation, that is, a focal length setting operation into three bits and outputs the coded signal.
The decoder (62) is a clock output terminal Sc of the control CPU (100).
The clock pulse from k (102) is counted and decoded. The addressing circuit (63) is
1) and a signal from the decoder (62) is selected, and the address of a read-only memory (64... In the ROM (64), unique information regarding the photographing lens in which the ROM (64) is mounted is stored in advance for each address. When the address of the ROM (64) is designated by the address designating circuit (63), the information stored at that address is output in parallel by the ROM (64). The P / S conversion circuit (65) converts the parallel signal sent from the ROM (64) into a serial signal and inputs the signal to the control CPU (100) via the mount contacts (723) and (713). Output to terminal Sin (103).

Further, the constant voltage Vcc is controlled through the mount contact (721) in the circuit (6) in the taking lens, and is connected to the ground line through the mount contact (725).

FIG. 2 shows three input / output terminals Sck (102), Sin (103), and CS (104) in the control CPU (100) shown in FIG. 1 in detail.

A high enable circuit is connected to the output terminal Sck (102), and the serial port control register (SCKC)
While the signal is high, a clock pulse is output from the body side to the lens side. The serial counter (120) is 1
This is a 3-bit counter for counting clock pulses of 8 bytes. Serial counter (120)
Counts one byte (eight) of clock pulses, the serial counter (120) generates an interrupt signal (INT) to the control CPU (100).

The input terminal Sin (103) is connected to the serial register (121), and one bit at a time according to the clock pulse.
Data sent from a specific address of the ROM (64) is temporarily stored in the serial register (121). The 8-bit data at a specific address of the ROM (64) held in the serial register (121) is transmitted to the random access memory in the body by an interrupt signal generated by the serial counter (120).
Stored in memory (hereinafter referred to as RAM).

Next, FIG. 3 shows an exploded perspective view of a schematic configuration of the optical device for focus detection used in the present invention.

In FIG. 3, TL ₁ and TL ₂ are photographing lenses, and the photographing lenses TL ₁ and TL ₂ each have a distance P from a predetermined image forming plane FP.
z ₁ , Pz ₂ (Pz ₁ <Pz ₂ ) (hereinafter, this distance is referred to as an exit pupil distance). And the planned image plane
A field mask FM is arranged near the FP. A horizontally long rectangular opening Eo is provided at the center of the field mask FM, while vertically long rectangular openings Eo ₁ and Eo ₂ are provided on both sides.
The light beams that have passed through the rectangular openings Eo, Eo ₁ and Eo ₂ of the field mask FM pass through condenser lenses Lo, Lo ₁ and Lo ₂ and are focused.

The re-imaging lens plate L includes a pair of re-imaging lenses L ₁ and L ₂ arranged in the center in the horizontal direction, and a pair of re-imaging lenses L ₃ , L ₄ and L arranged in the vertical direction on both sides. _5, it has a L _6. The re-imaging lens L ₁ ~L ₆ are all made of the same radius of curvature of the plano-convex lens. The aperture mask AM has a re-imaging lens L ₁
The aperture openings A _{1 to} A ₆ are provided at positions corresponding to L ₆ . The aperture mask AM is disposed immediately before the re-imaging lens plate L, and is in close contact with the flat portion of the re-imaging lens plate L.

The CCD line sensors Po are arranged horizontally in the center of the substrate, and the CCD line sensors Po ₁ and Po ₂ are arranged vertically on both sides of the substrate. The arrangement direction of the imaging lens pair is made to be the same as the direction of the CCD line sensor. Each of the CCD line sensors Po, Po ₁ , and Po ₂ has first and second two light receiving element arrays, and two re-imaged on the CCD line sensor by the re-imaging lens pair. The images are separately photoelectrically converted. Block AF surrounded by a dotted line in the figure
4 shows an (autofocus) sensor module.

The focus detection optical device having the above configuration detects the focus position as follows. Off-axis distance measuring luminous flux from a subject in an area off the optical axis of the photographing lens TL including the principal rays l ₃ and l ₄ ,
It passes through the rectangular opening Eo ₁ and incident on the field mask FM away from the optical axis at a predetermined angle with respect to the optical axis and incident on the condenser lens Lo _1. The incident optical axis distance light beam on the condenser lens Lo ₁ is focused with bent toward the optical axis by a condenser lens Lo _1, the diaphragm mask A
Re-imaging of the re-imaging lens plate L through the aperture openings A ₃ and A ₄ of M
Light is incident on L ₃ and L ₄ . Re-imaging lens L _3, off-axis distance measuring light beam incident on the L ₄ are, CCD by the re-imaging lens L _3, L ₄
Focused on line sensor Po ₁ and this CCD line sensor Po ₁
A pair of images is re-imaged on top. Similarly, the beam for off-axis distance measurement including the principal rays l ₅ and l ₆ is incident on the field mask FM so as to be away from the optical axis at the above-mentioned predetermined angle, and has a rectangular opening Eo ₂ , a condenser lens Lo ₂ , through the opening a _5, a ₆ and the re-imaging lens L _5, L ₆ diaphragm is focused onto the CCD line sensor Po _2, a pair of image is re-imaged on the CCD line sensor Po _2.

On the other hand, the luminous flux for distance measurement on the optical axis from the subject in the area including the optical axis of the photographing lens TL including the principal rays l ₁ and l ₂ includes a rectangular opening Eo on the optical axis, a condenser lens Lo, and an aperture opening. A ₁ ,
The light is focused on the CCD line sensor Po via A ₂ and the re-imaging lenses L ₁ and L ₂ , and a pair of images is re-formed on the CCD line sensor Po. Then, the CCD line sensor Po,
Po ₁ and captured by determining the position of the image of the pair of re-imaging of the three pairs tied on Po ₂ lens TL ₁ and TL ₂
Is detected for the subject.

Speaking of correspondence with the viewfinder inside view shown in FIG. 4, the CCD line sensor Po is in the on-axis focus detection area Fa, the CCD line sensor Po ₁ is in the off-axis focus detection area Fa ₁ , and the CCD line sensor Po ₂ respectively correspond to the optical axis outside the focus detection area Fa ₂ is.

A ₁₁ , A ₂₁ , A ₃₁ , indicated by broken lines on the photographing lens TL ₁
A ₄₁ , A ₅₁ and A ₆₁ and A shown by a broken line on the taking lens TL _2
12 , A ₂₂ , A ₃₂ , A ₄₂ , A ₅₂ and A ₆₂ are the aperture openings A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ of the aperture mask AM, respectively.
Shooting lens T by condenser lenses Lo, Lo ₁ and Lo ₂
Shows an image when it is back-projected onto the L ₁ and the photographing lens TL _2.
In other words, it indicates the range in which the light beam for distance measurement passing through the aperture openings A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ passes through the imaging lenses TL ₁ and TL ₂ . Therefore, the back-projected images A ₁₁ , A ₂₁ , A ₃₁ , A ₄₁ ,
A ₅₁ and A ₆₁ or A ₁₂ , A ₂₂ , A ₃₂ , A ₄₂ , A ₅₂ and A
_62, if Osamu' in the opening of the photographing lens TL ₁ or TL _2, CCD line sensors Po, the light beam incident on the Po ₁ and Po ₂ is, eclipsed by the pupil of the photographing lens TL ₁ or TL ₂ And high focusing accuracy can be obtained.

Here, in any case, the CCD line sensor P
The fact that the off-axis distance measuring light beam incident on o ₁ and Po ₂ is not vignetted with respect to the pupil of the photographing lens means that, as described above, the principal rays l ₃ and l of the off-axis distance measuring light beam _4, l _5, the l _6, the distance y is largely from the optical axis on the predetermined imaging plane FP, CCD line sensors Po _1, Po ₂
In a state where the aperture of the taking lens is small with respect to the distance from the optical axis of any
This means that the light beam for off-axis distance measurement that enters the D line sensors Po ₁ and Po ₂ passes through the opening of the photographing lens TL.

In the present invention, as described later, as information specific to various lenses, whether the above-mentioned CCD line sensors Po, Po ₁ and Po ₂ can be used without vignetting or not can be used as AF enable / disable signals in each lens. Is stored in the ROM.

FIG. 5 shows the aperture openings (A ₁ , A ₂ , A ₃ , A ₄ , A _{5) of the} aperture mask AM for predetermined pupil planes of various types of interchangeable lenses.
And A ₆ ) and back-projected images A ₁₂ , A ₂₂ , A ₃₂ , A ₄₂ , A ₅₂ and A ₆₂ of the condenser lenses Lo, Lo ₁ and Lo ₂ are shown.

FIG. 5A shows a case of a lens having a large aperture.
Since the aperture is large, all back-projected images can pass through the aperture for detecting the focus of the photographing lens TL, and all the distance measuring light beams incident on the CCD line sensors Po, Po ₁ and Po ₂ are photographing lenses.
It can be used without vignetting the TL pupil. That is, all the focus detection areas Fa shown in FIG. 4, it is possible to perform focus detection at Fa _1, Fa ₂ (see Table 1).

FIG. 5B shows the case of a lens having a small aperture.
For example, an interchangeable lens equipped with a teleconverter corresponds to this case. Since the aperture is small, the light beam that can enter the CCD line sensor without being vignetted by the pupil of the photographing lens TL is only the light beam for distance measurement on the optical axis. This is only the focus detection area Fa in the figure.

FIG. 5C shows the case of a lens whose opening position changes like a shift lens (shift lens here). When the shift amount is 0, only the focus detection area Fa effective for focus detection is used, but the shift amounts are X ₁ , X ₂ (0 <X ₁ <
X ₂ ), the effective focus detection area also changes (see Table 1).

FIG. 5 (d) shows the case of a lens having an irregular opening such as a reflective telephoto lens. The shaded area is where the luminous flux is vignetted due to the reflecting mirror (secondary mirror).
Focus detection area because it cannot enter the line sensor Po
It is impossible to perform focus detection with Fa.

On the other hand, the reflective telephoto lens shown in FIG. 5E has a small portion where the light beam is vignetted by the reflecting mirror, so that the light beam for distance measurement on the optical axis can enter the CCD line sensor Po.

As described above, which focus detection area is valid at the time of focus detection differs depending on the type of the interchangeable lens, and is stored in the ROM in the lens as lens-specific information (AF enable / disable signal) (see Table 1). 1).

Table 1 kind of differences due to available focus detection area of the lens _{(Fa, Fa 1, Fa 2} ) and the CCD line sensor (Po, Po _1, Po
₂ ) and an AF enable / disable signal. Focus detection area indicated by “○” in the table and CC arranged corresponding to it
The D line sensor can be used for focus detection. Also A
The F enable / disable signal is 8-bit data.

Fig. 6 shows the image plane best position and the CCD line sensor (A
3 shows the relationship with the stop position of the photographing lens under visible light and infrared light under an F sensor. The horizontal axis X is an axis along the optical axis, the left side is the direction of the photographing lens (+ direction), the right side is the direction of the film surface (− direction), and the vertical axis Y
Represents the distance from the optical axis in a plane perpendicular to the optical axis. In the figure, the position indicated as on-axis is the position where the image forming performance of the image formed by the on-axis light (incident light parallel to the optical axis) is the best, but the film surface in the camera is at this position. In this case, the aberration performance with respect to off-axis light (incident light inclined with respect to the optical axis) deteriorates, and a good defocus amount cannot be obtained by focus detection using a light beam for off-axis distance measurement. Therefore, in consideration of on-axis light and off-axis light, the film surface is located at a position slightly shifted from the on-axis position (image plane best position). The aberration curve shown as an image is based on this image plane best position,
The magnitude of the deviation due to the actual transmitted light of the photographing lens (open aperture, for example, F = 2.0) indicates the position where the image contrast is the best.

On the other hand, the AF sensor, as described above,
Alternatively, focus detection is performed using only the beam for off-axis distance measurement, resulting in an effect equivalent to increasing the aperture value of the photographing lens, and the aberration performance on the AF sensor is the aberration of the entire photographing lens. Better than performance. The focus determination position by the AF sensor is shown as an AF sensor stop position under visible light or infrared light. Focus detection under infrared light means that if focus detection with visible light is impossible, infrared light is projected from the auxiliary light circuit built in the camera body,
This is the result of focus detection under infrared light projection. The auxiliary light circuit may be provided in a device outside the camera, for example, in an electronic flash device.

As described above, there is a shift between the AF sensor stop position and the image plane best position, and the shift amount changes depending on the distance (image height) from the optical axis. Therefore, in the present invention, the shift amounts △ SBon, △ SBoff, △ sboff, △ IRon, △ IRoff, and △ iroff shown in the figure are stored in the ROM in the lens, and are corrected to the image plane best position. . The suffix ON is a correction amount for the focus detection area Fa for performing focus detection using the on-optical-axis distance measuring light beam, and the suffix OFF is a focus detection area Fa for performing focus detection using the off-optical-axis distance measuring light beam. _1, illustrating a correction amount related to Fa _2. Area F
Since a ₁ and Fa ₂ look at positions that are symmetrical with respect to the optical axis, correction can be performed using the same correction data.

ΔSB is the deviation amount between the defocus amount between the AF sensor stop position and the image plane best position under visible light, and Δsboff is
This is the difference between the stop position of the AF sensor on the optical axis and the position off the optical axis under visible light. ΔIR is the amount of deviation between the AF sensor stop position under infrared light and the AF sensor stop position on the axis under visible light, and Δiroff is the AF on the optical axis under infrared light and off-axis AF This is the difference between the sensor stop positions.

Since these shift amounts (△ SB, △ IR) change due to zooming or focusing of the taking lens,
The shift amount according to zooming or focusing is stored in the ROM in the lens as a correction amount. But,
Difference between the AF sensor stop positions on the optical axis and off the optical axis (△ sboff, △ ir
Since off) hardly changes due to zooming or focusing, this difference may be stored as a fixed value in the ROM in the lens.

Here, △ SBon, 図 SBoff, △ IRon,
ΔIRoff is a positive correction amount, and Δsboff and Δiroff are negative correction amounts.

When the correction amount (△ SB, △ IR) is made variable by focusing, a distance encoder is provided in the lens similarly to the zoom encoder (61) shown in FIG. 1, and the output of this encoder and the decoder (62) are used. The address of the ROM may be specified from the output of ()).

Hereinafter, the operation of the control CPU (100) in the camera body will be described with reference to the flowcharts of FIGS. 7 to 18.

FIG. 7 is a flowchart showing a main routine of an operation program of the control CPU (100). When the switch SW1, which is closed by pressing the release button in the first stage, is closed, the program is started from step # 700 (steps are omitted below), and various flags as shown in Table 2 are set in # 702. Reset to zero.

Table 2 describes various flags used in the control CPU (100). The details of the various flags will be described later.

In step # 704, since the ROM data is read for the first time since the control CPU is started, the read flag (F1) is set to 1, and the process proceeds to the lens data reading subroutine of step # 706. As will be described later, in the lens data reading subroutine, reading of ROM data, identification of lens attachment / non-attachment, identification of lens generation, and the like are performed, and the process returns to the main routine.

Next, the process proceeds to an automatic focus detection subroutine (hereinafter referred to as an AF subroutine) of # 708. In this AF subroutine, as described later, the focus of the subject is detected, and the lens is driven to bring the camera into a focused state.

In # 710, the film sensitivity data of the film cartridge inserted in the camera is read from the film sensitivity information circuit (360) into the control CPU, and in # 712, the photometric circuit (3
According to 10), photometry of the field luminance and A / D conversion are performed to obtain luminance value data. A known exposure calculation is performed based on the above data (# 714), and the obtained exposure-related value is displayed on a display circuit (340).
And display it (# 716).

Next, in step # 718, it is determined whether or not the switch SW1 is still turned on. If the switch SW1 is turned off, the process proceeds to step # 726, all the display circuits (340) are turned off and read. Reset the flag (F1) to 0 to control the CPU
Goes to sleep.

When the switch SW1 is determined to be on in # 718, it is determined in # 720 whether or not the switch SW2, which is closed by pressing the release button in the second stage, is on. If the switch SW2 is on, # 722 is determined. Performs a known release operation.
After the release operation is completed, the flow waits for the switch SW1 to be turned off at # 724, and proceeds to # 726. If the switch SW2 is off at # 720, the process returns to # 706 and repeats the operation from reading the lens data again.

FIG. 8 is a flowchart showing the lens data reading subroutine of FIG. 7 # 706. First, # 802
The read flag (F1) is 1 or 0, that is, the control CP
U Determine whether it is the first read of ROM data or the second or subsequent read after startup, and if it is the first read, # 804
If it is the second time or later, go to # 822.

Before describing the reading operation, lens information stored in the ROM in the lens will be described with reference to FIG.
The lens-specific information necessary for exposure control, AF control, etc., is stored in the interchangeable lens as 8-bit digital data.
Although the information is stored for each predetermined address in the ROM, when the camera is new and the functions are increased, the camera controls the new functions only with the information (conventional data) stored in the conventional lens (hereinafter referred to as the conventional lens). I can't do it. In this regard, a new lens (hereinafter referred to as a new lens) may be provided with a ROM that stores information (new data) corresponding to a new function in addition to the conventional information. FIG. 19 is a comparison diagram of the ROM area map between the conventional lens and the new lens.

The conventional lens, lens information d ₁ -DI by address 1~i
(Conventional data) is stored, and lens information dn (lens type identification data) is stored at the last address n. Addresses i + 1 to n-1 are empty addresses in which no lens information is stored. ROM mounted on the new lens using what capacity is identical to the ROM of the conventional lens, until the address 1~i conventional data d ₁ -DI have been stored as it. In addition, newly added lens information di + _{1 to} dj (new data) are newly stored at addresses i + 1 to j, which were empty addresses, and lens type identification data dn is stored at the last address n as in the conventional lens. It is remembered.

In the present invention, a lens which is defined as a conventional lens includes an image plane best position and an AF sensor stop position deviation amount (△) only in a focus detection area Fa in which focus detection is performed using a light beam for distance measurement on the optical axis. (SBon, △ IRon) is stored in the ROM in the lens as a correction amount (see Table 3). On the other hand, the new lens has a shift amount due to aberration with respect to the focus detection areas Fa ₁ and Fa ₂ (△ IRoff, △ SBoff or △ iroff, △ sboff).
Is newly memorized.

Returning to FIG. 8, the read flag (F1) is set to 1 at # 802.
, That is, the first ROM data reading operation after the control CPU is started will be described. Since it is the first load,
First, in step # 804, the number n of all addresses of the ROM is set in the serial data counter (N) as the number of data to be read, and in step # 806, the current lens state by zooming or focusing is indicated in accordance with the in-body reading subroutine described later. Read n bytes of ROM data into the RAM stored in the n bodies. This completes the first reading, so the reading flag (F1) is reset to 0
(# 808).

Data called ICP is stored at the head address of the ROM. The first two bits of the eight bits are used to identify whether the lens is a conventional lens or a new lens. It consists of lens generation identification bit data indicating whether the lens is a lens. In # 810, the first two bits of the ICP data are used to determine whether a lens is attached to the body or not, and if no lens is attached, the process proceeds to # 836. Then, the lens flag (F3) is reset to 0 indicating that the lens is not attached, and the AF flag (AFF) is set to 1 indicating that the AF operation is not performed (# 838), and the routine returns.

If it is determined in step # 810 that the lens is mounted, first, in step # 812, the lens flag (F
3) is set to 1, and the process proceeds to the step of # 814 lens generation identification. In step # 814, it is determined whether the attached lens is a conventional lens or a new lens by using the remaining 6-bit data of the ICP. If it is determined that the lens is a new lens, all necessary lens information is stored in the RAM in the body, so that the lens generation flag (F2) is reset to 0 in # 816 and the routine returns. When the lens generation flag (F2) is set to 1, it indicates that the conventional lens is mounted, and when it is 0, the new lens is mounted.

If it is determined in step # 814 that the attached lens is a conventional lens, the lens generation flag (F2) is set, and new data not stored in the conventional lens is stored in the body data table according to the in-body data table reference subroutine described later. From the RAM stored in the body (# 82
0), return.

If the read flag (F1) is determined to be 0 in # 802, the control CPU has already performed one or more read operations of the ROM data. Judge if it is a new lens (# 82
2). In the case of a new lens, the number j of ROM data is set in the serial data counter (N) as the number of read data (# 824), and in the case of a conventional lens, the number i of ROM data is set in the serial data counter (N) ( # 826), # 806
Execute the in-body read subroutine in the same way as
828). However, as described above, j> i, and the reading time of the ROM data is reduced by designating the number of data.

# 830 is a lens mounting identification step based on the read ICP data, similarly to # 810. If a lens is mounted, the process proceeds to # 832, and the lens flag (F3) is identified to determine the last time. At the time of reading the lens data, it is determined whether the lens is attached or not. The fact that the lens flag (F3) is 0 means that the lens has not been attached last time and the lens has been newly attached this time. Therefore, the lens flag (F3) is set to 1 indicating the lens attached state, and the process proceeds to # 804. Migrate and ROM again
Read n data.

FIG. 9 shows a subroutine for reading data into the RAM in the body shown in FIGS. # 806 and # 828, and shows an operation of reading ROM data into the RAM in the camera body. First sets ROM data storage head numbers m ₀ to RAM address pointer (M) at # 902. The RAM has an 8-bit configuration like the ROM. Next, at step # 904, the serial flag (F4) is reset to 0 to indicate that the reading of the serial data from the ROM is not completed, and the serial counter (120) shown in FIG. 2 counts the clock pulse for 8 bits. Is set to 8 (# 906).

When the output terminal CS shown in FIG.
Serial communication between the body and the lens becomes possible. # 91
0 sets the serial port control register (SCKC) to 1
Is set, the clock pulse starts to be output from the clock output terminal Sck shown in FIG. Step # 912 is a step of waiting for the completion of the processing of the serial interrupt. In this step, the serial interrupt is performed and the serial flag (F4) becomes 1 in other words.
This is a state in which one byte of serial data of the ROM is read into the RAM and is waiting.

The serial interrupt processing operation will be described with reference to FIG. When the serial counter (120) finishes counting eight clock pulses, it generates an interrupt signal (INT) to the control CPU. That is, while the control CPU is waiting for the serial flag (F4) to become 1 in # 912 in FIG. 9, the serial counter (120) finishes counting eight clock pulses and outputs an interrupt signal (INT). ), And the flow chart shifts to FIG. First, in # 1002, the serial port control register (SCKC) is reset to 0 in order to stop the output of the clock pulse from the body side to the lens side. Next, in # 1004, the data of the predetermined ROM address of 8 bits read into the serial register (121) is transferred to the address (initially m ₀ ) designated by the address pointer (M) in the RAM. Store. In # 1006, the address pointer (M) for designating the RMA address of the storage destination is advanced by one. In # 1008, as shown in FIG.
The serial flag (F4) is set to 1, the serial counter (120) is set to 8 for reading the next ROM data (# 1010), and the process returns to # 912 in FIG.

In # 912, it is determined that the serial flag (F4) is set to 1, so the flow proceeds to # 914. In # 914, 1 is subtracted from the serial data counter (N), and the serial flag (F4) is set. It is reset to 0 again (# 915).

The determination flow of # 916 determines whether all the ROM data corresponding to the number set in the serial data counter (N) has been stored in the RAM in the body, and if all the data has been read, N = 0. Therefore, at # 918, the output terminal CS is set to high to end the communication between the body and the lens, and the routine returns. If reading of all data has not been completed, the process returns to step # 910 to read the next ROM data.

FIG. 11 is a subroutine for referencing the in-body data table shown in FIG. 8 # 820. When a conventional lens is mounted, lens information (new data) not stored in the conventional lens is referred to the body data table. Then in the body
The operation of storing data in the RAM will be described.

FIG. 20 is an area map of the in-body data table. At the last n addresses of the ROM in the lens, lens type identification data (dn) is stored without distinction between the conventional lens and the new lens. Lens type identification data (dn) has the value of dn ₁ to dne depending on the type of lens. The data (di + 1 to dj) corresponding to the new data newly stored in the new lens according to the lens type of the conventional lens is stored in the in-body data table.

Returning to FIG. 11, first, in # 1102, the control CPU receives lens type identification data (dn) from the RAM. Received dn =
Based on dnk (1 ≦ k ≦ l), the in-body data table area number k is set in the counter (K) (# 1104), and the reference data number j from the in-body data table is set in the serial data counter (N). -Set i (# 1106),
Also, the lens ROM data storage start address m ₀ + i is set in the RAM address pointer (M) (# 1108). RAM m
₀ The ~m ₀ + i-1 address, are stored in a conventional data already stored in the ROM.

In # 1110, the data corresponding to the lens type identification data (dnk) is referenced by one byte from the data table in the body and stored in the RAM address specified by the address pointer (M). Thereafter, as in the case of the lens data reading subroutine, the data from the data table in the body to dj is referenced byte by byte and stored in the RAM.

Table 3 shows what kind of lens information is stored in the RAM stored in the body only for data used in the embodiment, and addresses are given for convenience. As already described in detail, in view of the correspondence with the lens side, the ROM of the conventional lens has at least 1 to 5 in the RAM.
And the lens information of the address n, and the lens information of the addresses 1 to 5, i + 1 to i + 4, and n in the RAM are stored in the ROM of the new lens. In the conventional lens, lens information corresponding to the contents of i + 1 to i + 4 is read from the data table in the body according to the lens type, and the lens information in the body is read out.
Stored in RAM. The indication (variable) indicates that the data is variable data that changes by zooming or focusing. The conversion coefficient K is obtained by dividing the lens drive amount by the defocus amount, and is used to calculate a lens drive amount necessary for focusing from a lens control defocus amount obtained by a focus detection operation described later. When the lens is not a shift lens, the shift amount of the shift lens is fixed to zero.

FIG. 12 is a flowchart showing the AF subroutine of FIG. 7 # 708.

In # 1202, the state of the AF flag (AFF) is determined. A
The F flag (AFF) is a flag which is set to 1 when the lens is not mounted in # 810 or # 830 in FIG. 8, or is set after the lens is in focus as described later. In other words, if the AF flag (AFF) is set to 1, either the camera is in focus or no lens is attached, and the flow returns without performing the focus detection operation (# 1246). If the AF flag (AFF) is 0, the state of the auxiliary light flag (F5) is determined in # 1204. If the auxiliary light flag (F5) is set to 1, the focus detection operation using the auxiliary light (F5) is performed. The process proceeds to # 1218 to # 1232).

If auxiliary light flag (F5) is 0 in # 1204, the AF sensor (CCD line sensor) Po, is integral with Po _1, Po ₂ is carried out in a known manner, integrated data is dumped in # 1206 (#
1208).

# 1210 is a subroutine of a focus detection calculation using the above-described integral data, which will be described with reference to FIG. # 1302 is a focus detection calculation for each focus detection region Fa, in each Fa _1, Fa _2.
Each AF sensor Po, Po ₁ , Po ₂ has a reference part and a reference part, respectively.
Two light receiving element rows are formed, and in the focus detection calculation,
By using the signals of these light receiving element rows, calculations such as a contrast calculation and a correlation calculation of the subject are performed, and data relating to the defocus amount which is data necessary for focus detection, data indicating the reliability of focus detection, and the like are created. Things. still,
For more detailed control, the present applicant has disclosed in
What is necessary is just to use the method filed in US Pat. The result obtained by this focus detection calculation is used for determining whether or not focus detection can be performed in each focus detection area and calculating the defocus amount, as described later.

In # 1304, various low contrast flags (LCF, LCF1, LCF2, LC
Reset F3). The low contrast flag is a flag indicating whether focus detection is possible or impossible based on the result of the focus detection calculation. If the flag is 1, the focus detection is impossible, and if the value is 0, the focus detection is possible. On the other hand, the above-mentioned AF enable / disable signal stored in the ROM in the lens is a signal for specifying an available focus detection area depending on the shape of the lens regardless of the result of the focus detection calculation.

In # 1306, based on the result of focus detection calculation for AF sensor Po ₁ that are arranged corresponding to the focus detection area Fa _1, allows focus detection in the focus detection area Fa _1, it is determined not, focus detection as if possible, Rokonfuragu for the area Fa ₁ in # 1308 if not the focus detection (L
CF1) is set to 1 and the flow shifts to # 1310. # 1310 to # 1316, similarly focus detection area Fa, the focus detectable in Fa _2, it is impossible for determination flow.

Next, in step # 1318, an AF enable / disable signal among lens information stored in the RAM in the body is received, and the data is stored as (00
H) to # 1320 (01H) to # 1330, (02H) to # 1
The process moves to # 336, to # 1344 if (03H), or to # 1350 if (04H) (see Table 1). In each flow,
In the focus detection area specified by the AF enable / disable signal, it is determined whether focus detection was possible or impossible by referring to the low contrast flag for that area. If the focus cannot be detected, the low contrast flag (LCF) is set to 1 and the routine returns. On the other hand, if there is at least one focus detectable area, the process directly returns. For example, if (02H) is received as the AF availability signal,
The process moves from # 1318 to # 1336. AF availability signal (02H)
Since designated Fa and Fa ₂ as a focus detection area, it is determined Rokonfuragu and (LCF2) possible not focus detection by the focus detection calculation based on (LCF3). If it is determined in step # 1338 that the low contrast flag (LCF2) is 0, it means that the focus can be detected in at least the focus detection area Fa, and the process returns. Even if the low-con flag (LCF2) is 1 in # 1338, the low-con flag (LCF2) in # 1340
F3) if is 0, the process returns so that can focus detection at least the focus detection area Fa _2. If both low contrast flags are 1, it means that the focus can be detected over the entire area. Therefore, the low contrast flag (LCF) in # 1342 is set to 1 before returning. The same applies when another AF availability signal is received.

Returning to FIG. 12, # 1212 is a flow for determining whether or not focus detection is possible over the entire area based on the low contrast flag (LCF) determined in the above-described focus detection calculation subroutine.
If the low contrast flag (LCF) is 1, it means that focus detection cannot be performed in all areas, so the focus detection operation using the auxiliary light after # 1218 after setting the auxiliary light flag (F5) to 1 in # 1216. Move to. In many cases, the focus detection is determined to be impossible by the focus detection calculation because the contrast of the subject is extremely low or the brightness of the subject is extremely low. The built-in auxiliary light is emitted to integrate the light received by the AF sensor. The focus detection calculations of # 1226 and # 1228 and the focus detection enable / disable judgment by the low contrast flag (LCF) are the same as in # 1210 and # 1212 described above. If focus detection is not possible even with light-receiving integration that emitted auxiliary light, a warning is displayed on the display circuit (340) in step # 1232 indicating that focus detection is not possible, and the AF flag (AFF) is set to 1. And return (# 1240, # 1246).

The defocus amount calculation subroutine of # 1214 or # 1230 will be described with reference to FIG. 14 to FIG.

FIG. 14 is an embodiment of a subroutine for calculating the defocus amount under visible light (A) # 1214, # 1402 through # 1402.
1406 indicates the defocus amount calculation in the focus detection area Fa _1. # Determines the state of Rokonfuragu (LCF1) corresponding to the focus detection area Fa ₁ in 1402, the flag (LCF1) focus detection in 1 if region Fa _1, i.e. to # 1408 so calculated impossible defocus amount Transition. In # 1404, the defocus amount (# 1) is calculated based on the result of the focus detection calculation. As described with reference to FIG. 6, there is a certain gap between the image plane best position, which is the actual film surface, and the AF sensor stop position by the focus detection by the AF sensor. Therefore, the defocus amount (# 1) obtained as a result of the focus detection calculation based on the output of the AF sensor cannot accurately indicate the image plane best position. So # 1406
Thus, an auxiliary calculation for focusing on the best position on the image plane is performed. That is, assistance is performed by the following operation Δξ1 ′ = △ ξ1 + △ SBon + △ sboff (1). Here, △ SBon is conventional data, data that can be changed by zooming or focusing, and △ sboff is new data, which is fixed data that does not change by zooming or focusing.

Similarly, # 1408 to # 1412 are flow charts for calculating the defocus amount in the focus detection area Fa. The defocus amount (△ ξ2) obtained based on the result of the focus detection calculation is corrected by the following calculation. I have.

Δξ2 ′ = △ ξ2 + △ SBon (2) That is, since the focus detection area Fa is focus detection using the light beam for distance measurement on the optical axis, correction is performed using only the conventional data ΔSBon. Of course, @SBon is variable data.

# 1414 to # 1418 is a calculation flow of the defocus amount in the focus detection areas Fa _2, as the correction calculation is the same as equation (1), as follows.

Δξ3 ′ = △ ξ3 + △ SBon + △ sboff (3) This defocus amount calculation under visible light (A) subroutine is characterized by variable data on the axis stored as conventional data in the ROM of the conventional lens as the conventional data. Using
This is the point that new off-axis variable data is created, and the only data (new data) to be stored for that purpose is the fixed data △ sboff. Also, the focus detection areas Fa ₁ and Fa ₂
Performs focus detection based on a light beam that has passed through a region substantially symmetrical with respect to the optical axis of the lens, so that only one correction amount (△ sboff) used for the correction operation needs to be stored.

FIG. 15 shows an embodiment of a defocus amount calculation (A) subroutine using the auxiliary light of # 1230. As in the defocus amount correction calculation under visible light in FIG. New variable data is created using the variable data of the conventional data. The flow of the flowchart is 14th
Since it is completely the same as the case of the figure, only the auxiliary calculation will be described.

When projecting infrared light as an auxiliary light onto a subject and receiving infrared light reflected from the subject to perform focus detection, the amount of defocus during focus detection under visible light due to lens chromatic aberration (See FIG. 6). Defocusing by the focus detection calculation obtained in the focus detection area Fa using the light beam for distance measurement on the optical axis (△
The correction of ξ2) is performed by the following equation.

Δξ2 '= △ ξ2' + △ SBon + (a × △ IRon + b) (4) Here, △ IRon is conventional data, which is variable by zooming or focusing. a
Is a correction coefficient indicating the ratio between the correction amount △ IRon 'of the auxiliary light used in the present embodiment at the used infrared wavelength and the correction amount △ IRon when using infrared light having a wavelength of 800 nm. For both the conventional lens and the new lens, the correction amount △ IRon stored as lens information is a correction amount at a wavelength of 800 nm.
When an auxiliary light having a wavelength other than 00 nm is projected, a correction corresponding to that wavelength is required. ΔIRo as the correction coefficient a
The reason for having the ratio of n 'to △ IRon is that the chromatic aberration of the photographing lens changes linearly in the infrared wavelength range, and this ratio does not change much by zooming or focusing. b is an autofocus sensor module used in the present embodiment (dotted line in FIG. 3, block AF portion)
Is the infrared light characteristic at the used infrared wavelength, that is, the ΔIR correction value of the autofocus sensor module. this
The correction coefficients or correction values of a and b are stored in the E ² PROM in the body.

On the other hand, focus detection area using off-axis distance measuring light beam
The correction of the defocus amount (△ ξ) obtained by Fa ₁ or Fa ₂ is based on the following equation.

Δξ ′ = △ ξ + △ SBon + (a × △ IRon + b + △ iroff) (5) Δiroff is new data and is fixed data that does not change due to zooming or focusing. The data to be stored as new data may be only the fixed data △ iroff.

FIG. 16 is a defocus amount calculation (B) subroutine under visible light, which is another embodiment of FIG. For correction in the focus detection areas Fa ₁ and Fa ₂ , variable data △ SBoff is stored in advance by zooming or focusing as new data without using variable conventional data (△ SBon). And That is, the correction of the defocus amount obtained by the focus detection area Fa ₁ or Fa ₂ (△ and xi]) is performed as follows.

Δξ ′ = △ ξ + △ SBoff (6) The focus detection area Fa is the same as the equation (2) using the on-axis correction data ΔSBon.

The capacity of the ROM for storing new data naturally increases by the amount that changes due to zooming or focusing, but the difference between the on-axis and off-axis AF sensor stop positions △ sboff
Is effective for a lens that greatly changes due to zooming or focusing.

FIG. 17 shows the defocus amount calculation using the auxiliary light (B)
This is a subroutine, which is another embodiment of FIG. No. 16
As in the figure, variable data ΔIRoff is stored as new data in the ROM in the lens by zooming or focusing. Therefore correction of the defocus amount obtained in the focus detection area Fa ₁ or Fa ₂ (△ and xi]) is performed as follows.

Δξ ′ = △ ξ + △ SBon + (a × △ IRoff + b) (7) For the focus detection area Fa, the on-axis correction data △ SBon,
Same as equation (4) using ΔIRon.

Returning to FIG. 12, # 1234 is the above # 1214 or # 12
This is a lens control defocus amount calculation subroutine for calculating a lens control defocus amount necessary for driving a lens from the defocus amounts of a plurality of focus detection areas obtained in 30. In # 1236, it is determined whether or not the current lens position is in focus based on the calculated control defocus amount. If the current lens position is in focus, the display circuit (34) is determined in # 1238.
At 0), a display indicating the in-focus state is performed, and the flow shifts to # 1240.
If the lens is not in focus, the necessary lens drive amount is calculated from the control defocus amount obtained by the control defocus amount calculation and the conversion coefficient K stored in the ROM (# 124).
2) Then, the lens is driven (# 1244), and the flow shifts to the in-focus display flow of # 1238.

FIG. 18 shows the control defocus amount calculation subroutine of FIG. 12 # 1234 in detail. First, in # 1802, an AF enable / disable signal is received from lens information stored in the RAM in the body, and the flow shifts to each flow according to the data. For example, if the AF enable / disable signal is (00H), △ ξ = f (△ ξ1 ′, △ ξ2 ′, △ ξ) of # 1806
The lens control defocus amount is calculated by 3 '). The function f is the defocus amount of a plurality of focus detection areas △
Only the effective defocus amount is selected from ξ1 ′, △ ξ2 ′, and △ ξ3 ′, and the lens control defocus amount is calculated in accordance with a predetermined evaluation algorithm. do not do. If the AF enable / disable signal is (01H), the defocus amount detected in the focus detection area Fa in # 1810 is directly used as the defocus amount for lens control. When the AF availability signal is (02H), (03H), or (04H), the defocus amount for lens control is calculated according to each flow. The details are described in, for example, JP-A-61-55618 filed by the present applicant.

(Effects of the Invention) As is clear from the above, the first lens (conventional lens) which does not have the second lens data (new data) necessary for performing the second function. In other words, the storage means in the camera body has second lens data for each type, and the type identification data (lens type identification data) specifies the second lens data unique to the lens, and the second function is Controlled.

Further, only the second lens data necessary for the first lens group needs to be stored in the camera body capable of performing the second function, and it is not necessary to store enormous data in the camera body. Absent.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall circuit configuration of an embodiment of the present invention, FIG. 2 is a diagram showing a configuration of an input / output terminal of a control CPU,
FIG. 3 is a schematic view of a focus detecting optical device according to an embodiment of the present invention, FIG. 4 is an inside view of a finder showing a focus detecting area of a field, and FIG. 5 is a pupil plane of various interchangeable lenses. FIG. 6 is a back-projection diagram of the aperture mask, FIG. 6 is a diagram showing a relationship between a focus position by the AF sensor and an image plane best position based on aberration of the photographing lens, FIG. FIG. 9 is a flowchart showing a ROM data reading subroutine, FIG. 9 is a flowchart showing a reading subroutine to the RAM in the body, and FIG. 10 is a control CP.
A flowchart showing a serial interrupt processing routine to U, FIG. 11 is a flowchart showing a data table reference subroutine in the body, FIG. 12 is a flowchart showing an automatic focus detection subroutine, FIG. 13 is a flowchart showing a focus detection calculation subroutine, and FIG. FIG. 14 is a flowchart showing one embodiment of a defocus amount calculation subroutine under visible light, FIG. 15 is a flowchart showing one embodiment of a defocus amount calculation subroutine using auxiliary light,
16 is a flowchart showing another embodiment of a subroutine for calculating a defocus amount under visible light, FIG. 17 is a flowchart showing another embodiment of a subroutine for calculating a defocus amount using auxiliary light, and FIG. 18 is a lens. 19 is a flowchart showing a control defocus amount calculation subroutine, a nineteenth embodiment;
The figure shows an area map of the ROM in the lens, and FIG. 20 shows the area map of the data table in the body.

Continuing from the front page (72) Inventor Hiroshi Otsuka 2-30 Azuchicho, Higashi-ku, Osaka-shi, Osaka Osaka International Building Minolta Camera Co., Ltd. Examiner Kiyonobu Kitagawa

Claims (1)

(57) [Claims] 1. A camera system in which a number of interchangeable lenses can be selectively used, wherein the interchangeable lens belongs to a first lens group among first and second predetermined lens groups. A first lens group storing identification data, type determination data indicating the type of lens, and first lens data unique to the lens necessary for the camera system to perform a predetermined first function; Lens group identification data indicating that the camera system belongs to the second lens group, lens-specific first lens data necessary for the camera system to perform a predetermined first function, and A second lens group storing lens-specific second lens data necessary for performing a new second function not included in the first function. The camera body includes a first lens group. Against camera system Storage means for storing second lens data necessary for the camera to perform the second function in accordance with the type of each lens, and which lens is mounted on the basis of the lens group identification data. Determining means for determining whether the lens belongs to the group; first lens data and lens stored in the lens when it is determined that the lens of the first lens group is mounted based on the determination result of the determining means; When predetermined control is performed based on the second lens data stored in the storage means in the camera body whose type discrimination data is specified according to the type, and it is determined that the lens of the second lens group is mounted. A camera system comprising: control means for performing predetermined control based on first and second lens data stored in a lens.