JPH01287509A - Interchangeable lens camera - Google Patents

Abstract

PURPOSE:To drive a manual focus adjusting member smoothly by starting driving a lens toward an infinite-distance position by its manual focus adjusting member a specific time after the lens or a battery is mounted. CONSTITUTION:When an interchangeable lens 1 is mounted on a camera body 2, a lens mounting detecting means 22 detects the mounting of the interchangeable lens 1. A timer means 23 starts clocking operation in response to the detection output of this lens mounting. The timer means 23 finishes the clocking operation the specific time later. A lens driving means 21 operates under the control of a control means 24 after the clocking means 23 finishes the clocking operation to drive the manual focus adjusting member 11 for the interchangeable lens 1, thereby stopping down a lens for focus adjustment toward the infinite- distance position. Namely, the probability that a photographer puts his hand away from the manual focus adjusting member 11 for the interchangeable lens 1 is high the specific time after the interchangeable lens 1 is mounted, so the manual focus adjusting member 11 for the interchangeable lens 1 is about to be driven. Consequently, the manual focus adjusting member 11 is driven without hindrance.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an interchangeable lens camera.
It is particularly suitable for single-lens reflex cameras with automatic focus adjustment.

[Prior Art] Conventionally, an interchangeable lens single-lens reflex camera having an automatic focus adjustment function is generally provided with a lens position counter within the camera body to detect the amount of lens extension. This lens position counter is reset when the lens is retracted to the infinity position, when the lens is extended to the edge, it counts up according to the amount of extension, and when the lens is retracted, it counts up according to the amount of extension. When switching from manual front point adjustment mode to automatic focus adjustment mode, or when a lens or battery is attached to the camera body, the lens is moved to the infinity position to reset the lens position counter. need to be included.

[Problem to be solved by the invention] However, when a lens is attached to a camera body or a battery is attached, the lens is often held in the hand, and when the focusing ring of the lens is driven in this state, However, there were problems such as overloading the focusing ring drive, causing the lens to stop halfway through, damaging the drive system, and causing photographers to accidentally drop the camera.

The present invention has been made in view of the above points, and its purpose is to provide an interchangeable lens type that allows lens retraction to be started after a predetermined period of time has elapsed when a lens or battery is attached. The purpose is to provide cameras.

[Means for Solving the Problems] In order to solve the above problems, the focus detection device according to the present invention includes a photographing device equipped with a manual focus adjustment member (11), as shown in FIG. A camera with an automatic focus adjustment function consisting of an interchangeable lens (1) and a camera body (2) to which the interchangeable lens (1) is attached, the camera body (2) being able to manually focus the interchangeable lens (1). Adjustment member (11
) and a lens driving means (21) for driving the interchangeable lens (
1) lens attachment detection means (22) for detecting attachment;
A timer (23) that starts a timekeeping operation when the lens attachment detection means (22) detects that the interchangeable lens (1) is attached, and ends the timekeeping operation after a predetermined period of time has elapsed; A control means (24) for controlling the lens driving means (21) so as to retract the manual focus adjustment member (11) of the interchangeable lens (1) toward the infinity position after the timing operation is completed.
).

However, FIG. 1 is an explanatory diagram showing the configuration of the present invention in functional blocks, and in the embodiments described later, the main part of the above configuration is realized by a microcomputer program.

Note that instead of the lens attachment detection means (22), a battery attachment means for detecting that a battery is attached to the camera body may be provided.

[Effect] Hereinafter, the operation of the present invention will be explained with reference to FIG.

When you attach the interchangeable lens (1) to the camera body (2),
Lens attachment detection means (22) detects attachment of the interchangeable lens (1). In response to this lens attachment detection output, the timer (23) starts a timer operation. After the predetermined time has elapsed, the timer (23) ends the timer operation. After the timer (23) completes the timekeeping operation, the lens drive means (21) operates under the control of the control means (24) and drives the manual focus adjustment member of the interchangeable lens (1) to adjust the focus. Retract the lens toward infinity.

Here, the manual focus adjustment member (11) of the interchangeable lens (1)
), a focusing ring provided on the outer periphery of the lens barrel of the interchangeable lens (1) is usually used. When attaching the interchangeable lens (1) to the camera body (2),
The photographer often holds such a manual focus adjustment member (11) in hand, but after a predetermined time (for example, 500 pans 5ec) has elapsed after attaching the interchangeable lens (1), the photographer is the manual focus adjustment member (1) of the interchangeable lens (1).
According to the present invention, at this time, the manual focusing member (1) of the interchangeable lens (1) is removed.
1) is configured to start driving, there is less possibility that the driving of the manual focus adjustment member (11) will be disturbed.

Although the photographer may hold the manual focus adjustment member (11) in his/her hand even when the battery is attached, a battery attachment detection means may be used instead of the lens attachment detection means 22) shown in FIG. If provided, there is a high probability that the photographer will have taken his hand off the manual focus adjustment member (11) when the manual focus adjustment member (11) starts to be driven, and the driving of the focusing member will be delayed. This reduces the possibility of interference.

[Embodiment] FIG. 2 is a block circuit diagram showing the circuit configuration of a camera as an embodiment of the present invention. However, illustrations of parts not directly related to the focus detection operation are omitted. (
μC) is a microcomputer that performs calculations and sequence control for focus adjustment. (LEC) is a lens circuit provided in the interchangeable lens, which transmits information specific to the interchangeable lens to the microcomputer (μC). (A.F.C.
) is a focus detection circuit that photoelectrically converts the subject light that has passed through the lens and outputs focus detection data.
μC). (DSP) is a display circuit that displays the focus of the lens and that the focus cannot be detected. (ILM) is an auxiliary light emitting device that irradiates the subject with auxiliary light for focus detection. (M) is a motor for driving the focusing lens of the interchangeable lens, and the lens drive circuit (
The lens drive circuit (LDC), which performs lens edge extension and retraction under the control of the LDC, receives motor drive speed signals, motor drive direction signals, and motor stop control from a microcomputer (μC). A signal is input, and the motor (M) is driven based on the signal. (ENC) is an encoder that detects the rotation amount of the motor (M), and the microcomputer (
output a pulse to μC).

Here, the microcomputer (μC) uses a lens position counter N to know the amount of lens extension from the infinity position, which is the most retracted state, as an absolute amount.
It has a built-in L. This lens position counter NL is reset to NL=O by an internal command when the lens is retracted to the infinite position, and when the lens is extended, the pulse from the encoder (ENC) is reset by an internal command. When the lens is renormalized, the encoder (
It is counted down according to the pulse from ENC).

When the lens is extended to the closest position, the value of the lens position counter NL becomes N1=Nmax. This maximum extension JINmax differs depending on the lens, and is read into the microcomputer (μC) from the lens circuit (LEC) as lens-specific information.

(BAT) is a power supply battery, and a microcomputer (
μC) and other circuits. Power battery (BA
A time constant circuit consisting of a series circuit of a resistor (R1) and a capacitor (C1) is connected to both ends of the resistor (T).
The connection point between R1) and the capacitor (C1) is connected to the power-on reset terminal (RES) of the microcomputer (μC). When the power battery (BAT) is connected, a power supply voltage is applied between the power terminal (Vcc) and the ground terminal (GND) of the microcomputer (μC), and the microcomputer (μC) becomes an active layer. ,
The microcomputer (μC) does not operate until the charging voltage of the capacitor (C1), that is, the voltage applied to the reset terminal (RES) of the microcomputer (μC) reaches a predetermined voltage. When the voltage exceeds a predetermined voltage, the microcomputer (μC) is reset and starts operation from step #1 (see FIG. 3), which will be described later.

(SR) is a reset switch, and this switch is OFF.
When N is pressed, the lens is reset to the initial position. (S
(2) is an infinity position detection switch, which is turned on when the lens is retracted to the infinity position. (Ss) is a main switch, which is turned on when the camera is used. (S
L) is the shooting preparation switch, and normally the release button (
(not shown) is turned on at the first stroke. (SAF)
is the AF mode switch, and this switch (SAF)
When the switch (SAF) is ON, the autofocus mode is selected to drive the lens to the in-focus position based on the focus detection result, and when the switch (SAF) is OFF, the autofocus mode is selected based on the focus detection result. Display only,
A manual focus mode in which lens drive is not performed is selected. (SMZ) is a macro zone switch,
In a zoom lens with a macro mechanism, the macro 8 used in this embodiment is released when the zoom ring is set to the macro zone. When using a zoom lens with a fence, when the zoom ring is set to the macro zone,
Since the autofocus monitor becomes unusable, in order to notify the microcomputer (μC) of this, the lens circuit (LEC) outputs a signal SMZ indicating the macro zone to the microcomputer (μC).

Next, the focus adjustment operation of the camera will be explained with reference to a flowchart. First, when the battery is installed and a power-on reset is performed, the microcomputer (μC) executes the programs starting from #1 shown in FIG. first,
#1 resets all flags. However, only the lens not installed flag LENOF (described later) should be set to 1, #
In step 2, lens data is input from the lens circuit (L E C). From the lens circuit (LE, C), a lens attachment signal ICP, a macro zone signal SMZ, a macro lens attachment signal LCPR1 larger than the same magnification, a maximum extension amount N wax , open aperture value AVo, focal length information ZFZ, conversion coefficient,
An AF enable signal AFE, an AP coupler signal AFCP, etc. are input to a microcomputer (μC). Here, the focal length information ZFZ is the focal length of the photographing lens [mm]
This is information obtained by logarithmically transforming , and in this embodiment, it is assumed that it is expressed by the following equation.

ZFZ=8X(21ogz(f/6.25)+11+
++■ Also, the conversion coefficient is a coefficient for converting the defocus IDF into the lens drive amount ΔN. The AF enable signal AF'E is a signal indicating that the interchangeable lens is a focus detectable lens. The AP coupler signal AFCP is used to transmit power to the interchangeable lens for automatic focusing (AF
This is a signal indicating that a coupler) is attached.

In #3, the presence or absence of the lens attachment signal ICP is determined. If the lens is attached, the lens circuit (LEC) supplies the lens attachment signal ICP to the microcomputer (μC), but if the lens is not attached, the lens attachment signal ICP is not supplied, so the microcomputer (μC) determines whether the lens is attached by checking the presence or absence of this lens attachment signal ICP.If there is no lens attachment signal at #3, it is determined that the lens is not attached, and at #8, the lens is not attached flag. Set LENOF to 1 and proceed to #10 (Fig. 4). Also, if there is a lens attachment signal in #3, it is determined that the lens is attached, and #
4, it is determined whether the flag LENOF is 1. If LENOF=1 in #4, it is determined that the lens is attached from the state where the lens is not attached, and the lens not attached flag L is set in #5.
Set ENOF to 0 and proceed to #6, 500 m5 in #6
After waiting for the time ec to elapse, the ω renormalization subroutine (FIG. 10) is executed in #7. Then, in #10, it is determined whether the main switch (SM) is ON. #
If the main switch (SM) is not ON at 10, #2
Returning to step 1, the presence or absence of the lens attachment signal is determined. Therefore, when the battery is attached and processing starts from #1, and when the lens is attached during the loop from #2 to #10, the subroutine for renormalization is executed after waiting for 500 m5ec. It turns out.

Here, to explain the reason for waiting for 500 m5ec, the photographer often holds the lens in his hand when attaching the battery or lens. If you start retracting the lens immediately after the
Lens retraction may stop midway, damage the lens or camera drive system, or the photographer may become surprised and drop the camera. To prevent this, 5
After waiting for a time of 00 e+see, lens retraction is started when the photographer takes his hand off the lens.

Next, if the main switch (S) is ON in #lO, the lens initial position calculation subroutine (9th
(Fig.), executes the renormalization subroutine (Fig. 10) in #20, executes the lens initial position setting subroutine (Fig. 11) in #25, and then turns on the main switch (SM) in #30. Determine whether it is OFF. If the main switch (SM) is OFF, the ω renormalization subroutine is executed in #35, and the process returns to #2 (FIG. 3). If the main switch (SM) is not OFF in #30, proceed to #45.

FIG. 9 is a flowchart showing the contents of a subroutine for calculating the lens initial position. When this subroutine is called, first, in #1000, lens data is input from the lens circuit (LEC).

In #1005, the macro lens attachment signal LCP
Determine the presence or absence of R. If the macro lens of equal or larger magnification is attached in #1005, the defocus amount DFs for setting the lens initial position is set to DF+s/2 in #1040, and the process returns to the step where the subroutine was called. Here, DFm is the maximum defocus amount that covers the range from the closest position to the infinity position of the lens. #10
If a macro lens of 100% magnification or higher is not installed in 05,
Defocus amount DFs is determined in #1010 to #1030. In #1010, it is determined whether the focal length information ZFZ is 40 or less, and if ZFZ≦40, in #1020
Then, return with DFs=O. ZFZ with #1010
If >40, the defocus amount DFs corresponding to the lens initial position Ns is calculated based on the focal length information ZFZ in #1030, and the process returns.

Here, the meaning of the algorithm for determining the initial lens position shown in #1010 to #1030 will be explained.

In this algorithm, the lens initial position rI1. The defocus amount DFs (μ餉) up to Ns is calculated. Using the above calculation formula (■), the focal length f is 24an to 80(1
Figure 14 shows the results of calculating the defocus amount DFs at the initial lens position Ns and calculating the imaging magnification β=DFs/f for the case of +m.As can be seen from Figure 14, the above formula 0 is The focal length used f(35
The defocus amount DFs at the lens initial position Ns is determined so that a commonly used imaging magnification β (1/80 to 1/40) can be obtained for a lens with a diameter of +us to 300 mm. If the focal length is handled in millimeters within the camera body, then simply DFs-β×r×
It would be sufficient to set it to 1000 [μ], but in reality, the focal length f is treated as information ZFZ logarithmically compressed using the above equation 0 within the camera body. in this case,
Although it is not easy to obtain the defocus amount DFs (μugliness) as a linear function of the focal length information ZFZ so that the condition of 1/80≦β≦1/40 is satisfied, the above 0
The formula is the realization of this. When calculating the photographing magnification β(f) using the above formula 0, β(f)” (in(f)
-1n(6,25X4)1/r. dβ/c
If the maximum value is determined from the condition of lf=0, it will be (1/β)-46 when f=681.

Also, when f=331I11, (1/β)=80.5
, when f=30011I11, (1/β)=81.7
becomes.

Moreover, in the above formula 0, the multiplication coefficient is 64=2'', so after subtracting the constant 40 from the focal length information ZFZ, the defocus amount DFs at the initial lens position Ns can be calculated by simply shifting to the left six times. Therefore, the defocus amount DFs at the initial lens position Ns can be calculated from the focal length information ZFZ read from the lens circuit (LEC).
can be easily calculated, the calculation time can be shortened, and the storage capacity of the calculation program can be reduced. Furthermore, compared to a method in which the defocus amount DFs of the lens initial position Ns is stored in advance according to various focal pressures 1wf, the storage capacity of the ROM can be reduced.

(Margins below) Table 1 However, in the above table, * means 28-135II+s when the zoom lens is on 1351, ↑ means 70-210III+11 when the zoom lens is on 210as, the customer is on 75-300III1
This is data when the No. 1 zoom lens is at 300mm.

Table 1 shows commonly used photographic magnification β and maximum defocus amount DF for lenses with various focal lengths.
− is shown. In a wide-angle lens with a focal length f of less than 35 wheels, the maximum defocus amount DFm is small, and it is considered that focus can be detected no matter where the lens position is. Therefore, it is considered that the lens should be stopped at an infinity position so as to obtain the commonly used photographic magnification of 1/co. Therefore, in this embodiment, f≦24 IIm(Z F Z
≦40), DFs=O. On the other hand, for lenses with commonly used focal lengths (35 to 300-11), commonly used imaging magnifications are distributed in the range of 1/40 to 1/60. The range of imaging magnifications that enable focus detection is thought to be slightly wider than this, 1/40 to 1/80.
It is thought that if the initial stopping position of the lens is determined so that a photographing magnification within the range of can be obtained, the probability that focus can be detected will be increased. Therefore, in this embodiment, f>24 mm (Z
In the case of FZ>40>, using the above formula 0, 1/80
The defocus amount DFs of the lens initial position Ns such that ≦β≦1/40 is calculated.

FIG. 10 is a flowchart showing the contents of the subroutine of (1) renormalization. When this subroutine is called, a lens condition determination subroutine is executed for $1100. Here, the lens condition determination subroutine is
An example will be explained with reference to FIGS. (a) and (b).

In FIG. 12(a), first, in #2000, the presence or absence of the lens attachment signal ICP is determined. If there is a lens attachment signal in #2000, it is determined in #2010 whether the open aperture value AVo of the lens is smaller than a predetermined value AFAV. Here, the predetermined value AFAV is the size of AF [[i through which the focus detection light flux passes, expressed as an aperture value. Open aperture value AVo
is smaller than the predetermined value AFAV, the focus detection light beam passing through the AF pupil will not be eclipsed by the lens.

If A Vo< A F A V in #2010, #
In 2020, the presence or absence of the AF enable signal AFE is determined. #2
If the AF enable signal AFE is present in step 020, it is determined that a focus detectable lens is attached, and the process returns with the lens condition flag LOKF set to 1 in step #2030. #20
If there is no lens attachment signal at 00, lens renormalization is not possible, so set the lens condition flag LOK at #2040.
Return with F set to 0. A V o≧ in #2010
In the case of AFAV, the focus detection light flux passing through the AF pupil is vignetted by the lens, so it is determined that accurate focus detection cannot be performed, and the lens condition flag L is set in #2040.
Return with OKF set to 0. If there is no AF enable signal AFE in #2020, it is determined that a lens whose focus cannot be detected, such as a reflective telephoto lens or a shift lens, is attached, and the process returns with the lens condition flag LOKF set to 0 in #2040.

FIG. 12(b) is another example of lens condition determination, #2
After determining the presence or absence of the ICP installation signal in step 000, if there is a CP installation signal, the presence or absence of the AF coupler signal AFCP is determined in #2025.

If AF coupler signal AFCP is present in #2025, AF
It is determined that a lens equipped with a coupler, that is, a lens that can be driven for focusing by the motor of the camera body, is attached, and the lens condition flag is set at 82030.
Return with F set to 1.

If there is no AF coupler signal AFCP in #2025, A
It is determined that a lens without an F coupler is attached, and the process returns with the lens condition flag LOKF set to O in #2040.

If the lens conditions shown in FIG. 12(a) or (b) are satisfied, the lens condition flag LOKF becomes 1, and if the lens conditions are not satisfied, the lens condition flag LOKF becomes 0. Returning to the flow in Figure 10, #
In step 1102, the lens condition flag LOKF is determined. #
If LOKF=0 in 1102, #1104~$11
Skip step 15 and return. #110
If LOKF=1 in 2, lens renormalization is started in #1104. After starting lens drive in #1104,
In #1105, it is determined whether the infinite position detection switch (S, :x)) is ON. #1105 is the switch (Sω
) is not ON, the judgment operation in #1105 is repeated until the switch (S■) is ON, and in #1105 the lens is retracted to the infinity position and the switch (Sω) is turned ON.
If N, lens renormalization is stopped at #1110, and #
At step 1115, the lens position counter NL is reset, and the subroutine returns to the called step.

FIG. 11 is a flowchart showing the contents of the subroutine for setting the lens initial position. When this subroutine is called, the lens condition determination subroutine is executed in #1200, and the lens condition flag LOKF is determined in #1202. If LOKF=O in #1202, #12
Skip steps 04 to #1215 and return. If LOKF=1 in #1202, the defocus amount DFs for setting the lens initial position is multiplied by the conversion coefficient K in #1204 to obtain the lens drive amount ΔN from the infinity position.
=DFsXK is calculated, and lens extension is started in #1205. In #1210, it is determined whether the lens drive amount has reached ΔN. If the lens driving amount has not reached ΔN in #1210, #1 until the lens driving amount reaches ΔN
The determination operation of step 210 is repeated, and when the lens drive amount reaches ΔN in #1210, the lens drive is stopped at $1215, and the process returns to the step where the subroutine was called.

Returning to the flow of FIG. 4, in #45, it is determined whether the AF mode switch (SAF) is ON.

If the AF-T switch (SAF) is not ON in #45, set the flag MF indicating manual focus mode to 1 in #50, and proceed to #80, #45
If the AP mode switch (SAF) is ON, #5
5, it is determined whether the flag MF is 1 or not. MF with #55
If = 1, it means that the switch (SAF) has just been turned on, and the flag MF is set to 0 in #60 and the flag MF is set to 0 in #65.
In #65 to #75, the above-mentioned lens initial position calculation, renormalization, and lens initial position setting subroutines are executed to set the lens initial position, and then,
Proceed to #145. If MP=1 is not found in #55, it means that the switch ('5AF) has been ON before, and the process proceeds to #80.

In #80, the presence or absence of the lens attachment signal ICP is determined.

If the lens is not attached at #80, the flag LENOF indicating that the lens is not attached is set to 1 at #100, and the process proceeds to #105.If the photographic lens is attached at #80, the flag is set at #90. Determine whether LENOF is 1. If LENOF=l in #90, it means that the lens has just been attached, and the flag LENOF is set in #95.
Set F to 0, wait until 500 m5ec has passed in #96, set the initial lens position in #65 to #75, and then proceed to #145.If LENOF is not 1 in #90, the previous This means that the lens was attached, so proceed to #105.

At #105, the macro zone switch (SMZ) is turned on.
In other words, it is determined whether the zoom lens is in the macro zone. Macro zone switch (SM) with #105
Z) is not ON, that is, if it is in the macro zone,
In #110, the flag SMZOFF indicating that the macro zone switch (SMZ) is OFF is set to 1, and in #12
Advance 5 Gm, macro zone switch (SM) at #105.
Z) is ON, it is determined in #115 whether the flag SMZOFF is 1. If SMZOFF=1 in #115, it means that the macro zone switch (SMZ) has just been turned on, and the flag SMZOFF is set in #120.
After setting the initial position of the lens in #65 to #75, proceed to #145 and turn SMZOFF in #115.
If not = 1, the macro zone switch (Ss
z) was turned on, and the process advances to #125.

In #125, it is determined whether the reset switch (SR) is ON. If the reset switch (SR) is not ON in #125, the reset switch (SR) is turned on in #130.
The flag 5ROFF indicating that is OFF is set to 1,
Proceed to #145, reset switch (SR) at #125
If it is ON, it is determined in #135 whether the flag 5ROFF is 1.

If 5ROFF=1 in #135, it means that the reset switch (SR) has just been turned on, and #140
After setting flag 5ROFF to O and setting the lens initial position in #65 to #75, proceed to #145, #135
If 5ROFF = 1, it means that the reset switch (SR) has been turned on before, and the lens has already been set to the initial position, so #65 to #7
The process proceeds to #145 without performing the lens initial position setting in step 5.

Therefore, after setting the lens initial position (#15 to #25) immediately after turning on the main switch (SM),
Immediately after the F mode switch (SAF) is turned on, immediately after the lens is attached, or the macro zone switch (SMZ)
) is turned on, or the reset switch (SR
) is turned ON, or when the focus cannot be detected even after performing the low contrast scan described below (#25).
The lens initial position is set only in cases (see 2); in other cases, the lens initial position is not set. Therefore, when shooting similar scenes or when shooting multiple pictures in succession When the probability of focusing near the previous lens position is high, as in the case of the previous lens position, the initial lens position is not set, and power consumption is lower than when the lens initial position is set every time the focus is detected. , and the time required for focus adjustment is shortened.

In #145, it is determined whether the photographing preparation switch (Sl) is ON. If the photographing preparation switch (Sl) is not turned on, the entire display is turned off in #40 and the process returns to #30. Below, #30, #45, #80, #105, #125
, and #145, check the status of the main switch (SM), AP mode switch (SAF), lens attachment signal TCP, macro zone switch (SMZ), reset switch (SR), and shooting preparation switch (Sl). Monitor.

In the middle of this loop, the main switch (SM) is turned off.
When it is, as mentioned above, ω renormalization (#35)
The lens is attached while going through the loop #2 to #10 again, or the main switch (SM) is turned off.
Wait until N. Also, in the middle of the loop from #30 to #145, switches (SAF), (SMZ), (SR
) is turned on, or when a lens is attached, the lens initial position set (#65~
#75) In this way, the camera is waiting for the shooting preparation switch (Sl) to be turned on, but #14
If the photographing preparation switch (Sl) is turned ON in step 5, the process proceeds to #175 (FIG. 5) to start focus detection.

Focus detection is performed in #175, and it is determined in #180 whether focus detection is impossible. If focus cannot be detected in #180, proceed to #290 (Figure 7) to perform focus determination.
If the focus cannot be detected in #180, it is determined in #185 whether the brightness is low. If the brightness is low in #185, proceed to #330 (Fig. 8) to emit the auxiliary light. If the brightness is not low in #185, proceed to #190 (Fig. 8) to find a lens position where contrast can be obtained. Proceeding to Fig. 6), a low-contrast scan is performed, but by limiting the range of the low-contrast scan to the narrowest possible range, an effort is made to shorten the time required for the low-contrast scan. In other words, in the focus detection device, the range in which focus detection is possible is determined, and from the current lens position to the rear bin side +DFa,
Assuming that focus detection is possible within the defocus amount range of -DFa on the front focus side, focus detection is possible within the range of ±DFa from the current lens position without changing the lens position. It is within. Therefore, #190
(Fig. 6), the scanning amount in the feeding direction is ΔN=N
Calculate as a+ax-NL-DFaXK. this is,
Even if you do not extend it to the maximum extension level 7flNmax,
If you extend it to the front position by DFaXK, the maximum extension position N + * ax will also be within the focus detectable range 2DFa.
In #200, it is determined whether the flag FOWF is 1. This flag FOWF is a flag indicating that scanning is to be performed in the direction (FOWard). When performing a low contrast scan for the first time, the flag FOWF is reset, so FOWF is not 1. Therefore,
First, proceed to #205, set F0WF-1 in #205, and proceed to #220. In #220, a signal is output to the lens drive circuit (LDC) to drive the lens (in the feeding direction), and in #225, After performing focus detection, #230
Determine whether focus detection is impossible. If the focus cannot be detected in #230, the flag FOWF is reset in #233, and the process proceeds to #290 (Fig. 7) to determine focus. If the focus cannot be detected in #230, the lens is adjusted in #235. It is determined whether the drive amount has reached ΔN. If the lens drive amount has not reached ΔN in #235, return to #225,
While continuing to drive the lens in the extending direction, it is determined whether the focus cannot be detected. If the lens drive amount has reached ΔN in #235, the lens drive is stopped in #240, and in #24
5, it is determined whether the flag FOWF is 1 or not. #245
If FOWF=1, this means that a lens position where the focus can be detected was not found even though scanning was performed in the extending direction, so the process returns to #200 to perform scanning in the retracting direction. FOWF with #200
If =1, it means that the scan in the feed-out direction has already been completed, so in #210, the scan amount in the renormalization direction is set to ΔN = N wax. This is to reset the counter by carrying it out to the end. #2
In step 15, the flag FOWF is set to 0 to indicate that the scan is in the renormalization direction, and the process proceeds to #220. #22
At #0, a signal is output to the lens drive circuit (LDC) to drive the lens (in the renormalization direction), and #225 to #240
After that, the process returns to #245. This time, since FOWF = 1, it does not return to #200 and proceeds to #250. In other words, when FOWF = 1 in #245, both the scanning in the feeding direction and the scanning in the renormalizing direction are performed. , Since no lens position where focus detection was possible was found, in preparation for the next focus detection, a subroutine for calculating the initial lens position was executed in #250, and a subroutine for setting the initial lens position was executed in #252. After that, in step #255 (FIG. 7), a focus detection failure display is performed. Note that while scanning in the renormalization direction, #
If the focus becomes detectable in step 230, the flag FOWF is reset in step #233, and the flag FOWF is reset in step #29 to perform focus determination.
Proceed to 0 (Figure 7).

When displaying focus detection failure in #255 (Fig. 7), #2
At 60, set the low contrast scan end flag LSENDF to 1
shall be. This flag is a flag to indicate that a low contrast scan was performed but no lens position where the focus could be detected was found.Next, after returning the flag FOWF indicating the scan direction to 0 in #265. , it is determined in #270 whether the photographing preparation switch (Sl) is ON. #27
If the shooting preparation switch (Sl) is not ON at 0, #4
Press o to erase all display and return to #30. If the photographing preparation switch (Sl) is ON in #270, focus detection is performed in #275, and it is determined in #280 whether focus cannot be detected. If the focus cannot be detected in #280, the process returns to #270.

If the focus is not detectable in #280, the low contrast scan end flag LSENDF is set to 0 in #290, and #29
5 to determine whether the image is in focus. If it is determined that the focus is not in focus in #295, the process proceeds to #300 to erase the in-focus and focus detection failure display, calculate the lens drive amount ΔN=DFxK based on the defocus amount DF in #305, and calculate the lens drive amount ΔN=DFxK in #310. Start driving the lens. In #311, it is determined whether the lens drive amount has reached ΔN. If the lens drive amount has not reached ΔN in #311, the determination operation in #311 is repeated until the lens drive amount reaches ΔN. If the lens drive amount reaches ΔN in #311, the lens drive is stopped in #312. , return to #270. Press #270 to turn on the shooting preparation switch (S
If l) remains ON, focus is detected in #275, followed by steps #280 to #290, and again in #295 to determine focus.The lens is focused in steps #305 and #310 described above. Since the lens is being driven toward the desired position, there is a high possibility that it will be in focus at this point.

If it is in focus at #295, the focus is displayed at #315,
In #320, it is determined whether the photographing preparation switch (Sl) is ON. At #320, the shooting preparation switch (Sl) is turned on.
If so, the determination operation of #320 is repeated until the photographing preparation switch (Sl) is no longer ON, and a so-called focus lock state is established. Although unrelated to the present invention, in a camera in focus priority mode, release is permitted in this focus lock state, and when the release button (not shown) is pushed to the second stroke, the camera releases. It is something that performs an action. If the photographing preparation switch (Sl) is no longer ON in #320, the display is turned off in #40 and the process returns to #30. That is, by turning off the photographing preparation switch (Sl), the above-mentioned focus lock state is released.

Next, when passing through #330 in Figure 8, it is determined that the brightness is low and focus cannot be detected in #185 and #180 (Figure 5), so auxiliary light emission is necessary. However, there are cases where it is useless to emit the auxiliary light, so #3
30 and #335, the auxiliary light emitting device (ILM) shown in FIG. On the other hand, the focus detection circuit (AFC) includes a focus detection optical system using a TTL phase difference detection method, and its optical axis is aligned with the light of the photographing lens. Therefore, the luminous flux area of the optical system for auxiliary light projection and the luminous flux area for focus detection have variax, and the luminous flux area of the optical system for auxiliary light projection and the luminous flux area for focus detection have a variation, and the distance (
(changes depending on the angle of view), the light flux range for focus detection is completely included in the light flux range of the optical system for flashing the filler light. This is the lower limit of the range that can be illuminated, and it is useless to emit filler light for objects closer than this. Furthermore, when camera C is equipped with a long focal length lens, the auxiliary light is vignetted by the lens barrel, so the auxiliary light does not hit the subject, and even if the auxiliary light is emitted, it may be wasted. Note that the lower limit of the range in which the subject can be illuminated to enable focus detection with fill light can be reduced by adopting a TTL fill light system, but the upper limit of the range in which focus detection is possible with fill light irradiation can be made smaller. The thing is,
Since the reach distance of the auxiliary light is about 10 rings at most, we cannot expect much.Therefore, in #330, it is determined whether the focal length of the lens is 2501 or more, and in #330, r≧
If it is 250, it is determined that the auxiliary light may be vignetted due to the long lens length or large lens diameter, so proceed to #190 (Figure 6) without emitting the auxiliary light, and set the low contrast. Perform a scan.

In addition, when shooting with a long focal length lens, there are many long-distance shots where the auxiliary light does not reach, so there is not much problem with disabling the auxiliary light.If it is #330 and f≧250, then #3
At step 35, it is determined whether there is a macro lens attachment signal LCPH of equal or greater magnification. If a macro lens of equal or larger magnification is attached in #335, it is determined that the shooting is at close range, which is closer than the lower limit of the range where focus detection is possible with auxiliary light irradiation, and the auxiliary light is not emitted. Proceed to #190 (Fig. 6) and perform a low-contrast scan.If a macro lens of 100% magnification or higher is not attached in #335, emit an auxiliary light in #340, perform focus detection in #345, and # At 350, it is determined whether focus detection is impossible. The auxiliary light is emitted only for a predetermined period of time for each focus detection.

If the focus is not detected in #350, proceed to #395.
If focus cannot be detected in #350, perform ■ renormalization in #355 to reset the counter, and #
At 370, auxiliary light is emitted, at #375 focus detection is performed, and at #380 it is determined whether focus detection is impossible. #38
If the focus is not detected at 0, proceed to #395, #38
If the focus cannot be detected with 0, it is determined whether the lens is at the initial position in #381, and if the lens is not in the initial position, the lens initial position is set in #382, and #3
In step 83, a flag indicating that the lens is at the initial position is set, and if focus detection is not possible even in the 0th focus detection, the process proceeds to #390, and the process proceeds from #381 to #385 to display a focus detection failure display. Press #390 to turn on the shooting preparation switch (Sl)
) is ON. If the photographing preparation switch (Sl) is ON in #390, the process returns to #375. #39
If the shooting preparation switch (Sl) is not ON at 0, #4
Clear the display with 0 and return to #30.

In #395, the focus detection failure display is erased, and in #400, it is determined whether focus is achieved. If the focus is #400, #4
20 indicates the focus, and #425 sets the shooting preparation switch (
SL) is ON. If the shooting preparation switch (Sl) is ON in #425, the shooting preparation switch (Sl) is turned on.
The determination in #425 is repeated until the photographing preparation switch (Sl) is no longer ON in #425, the display is turned off in #40, and the process returns to #30. #40
If the value is 0 and the focus is not in focus, the lens drive amount ΔN=DFXK is calculated from the defocus amount DF in #405, and lens drive is started in #410. In #412, the lens drive amount is Δ
Determine whether N has been reached. With #412, the lens drive amount is Δ
If N has not been reached, the determination operation in #412 is repeated until the lens drive amount reaches ΔN. If the lens drive amount reaches ΔN in #412, the lens drive is stopped in #413, and the shooting preparation switch is switched in #415. It is determined whether (Sl) is ON. At #415, the shooting preparation switch (Sl) is set to O.
If it is N, the process returns to #370, and if it is not ON, the display is turned off in #40 and the process returns to #30.

Determining the defocus amount DFs in the lens position calculation subroutine (Fig. 9) described above (#1010 to #10)
In the algorithm 30), focal length information ZF
Depending on Z, the defocus amount DF of the lens initial position Ns
s is being calculated.

FIG. 13 is a flowchart showing a modification of this algorithm, which can be used in place of steps #1010 to #1030. In #1500,
It is determined whether the focal length f is 28III11 or less (ZFZ≦a). If #1500 and f≦28 plow copper, #
Set 0 as the photographing magnification β in 1510 and proceed to #1570. If f>28mm in #1500, proceed to #1520
It is determined whether the focal length f is 210 mm or less (Z F Z≦b). If it is 15210mm in #1520, set the photographing magnification β to (1/40) in #1530 and proceed to #1570.If f>210 in #1520, the focal length f is 600-600mm in #1520. Below the ring (Z
Determine whether FZ≦C). #1540 and f≦6
If it is 001, use #1550 to set the imaging magnification β to (1/
60) and proceed to #1570, #1540tef
> If you have 600 au, use #1560 to increase the magnification β.
Set (1/100) as (1/100) and proceed to #1570, #
At 1570, the lens edge l D F s from the infinity position to the lens position Nb is calculated by multiplying the imaging magnification β by the focal length information ZFZ. In the algorithm shown in FIG. 13, the focal length f is, for example, from 35 to 10
In the case of 5 mm, the focal length f and the imaging magnification β = (1/4
0) is selected. In other words, the lens is always initially set at a position where an imaging magnification of (1/40) can be obtained.

[Effects of the Invention] As described above, the present invention provides the following features: After attaching the lens or battery,
After a predetermined period of time has elapsed, the manual focus adjustment member of the lens starts to move toward the infinity position of the lens, so even if the photographer holds the manual focus adjustment member of the lens in his hand when the lens is attached or the battery is attached, the manual There is a high probability that the photographer will take his hand off the manual focus adjustment member of the lens when the focus adjustment member starts to be driven, and therefore there is an effect that the possibility that the manual focus adjustment member will be disturbed can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a block circuit diagram of an embodiment of the present invention, and FIGS.
The figure is a flowchart showing the same operation as above, and FIG. 14 is an explanatory diagram of the same operation. (1) is a lens, (2) is a camera body, (11) is a manual focus adjustment member, (21) is a lens driving means, (22)
is a lens attachment detection means, (23) is a timing means, (24)
is a control means.

Claims (2)

[Claims] (1) A camera with an automatic focus adjustment function consisting of an interchangeable lens for photography equipped with a manual focus adjustment member and a camera body to which the interchangeable lens is attached, the camera body driving the manual focus adjustment member of the interchangeable lens. a lens driving means for detecting attachment of the interchangeable lens; a lens attachment detection means for detecting attachment of the interchangeable lens; and a timekeeping operation is started when attachment of the interchangeable lens is detected by the lens attachment detection means, and the timing operation is ended after a predetermined time has elapsed. What is claimed is: 1. An interchangeable lens camera comprising: a timer; and a control means for controlling a lens drive means to retract a manual focusing member of an interchangeable lens toward an infinity position after the timer completes a timekeeping operation. (2) A camera with an automatic focus adjustment function consisting of an interchangeable lens for photography equipped with a manual focus adjustment member and a camera body to which the interchangeable lens is attached, the camera body driving the manual focus adjustment member of the interchangeable lens. a lens drive means for detecting battery attachment to the camera body; a battery attachment detection means for detecting attachment of a battery to the camera body; and a timekeeping operation that starts when the attachment of the battery is detected by the battery attachment detection means and ends the timekeeping operation after a predetermined time has elapsed. and a control means that controls a lens drive means to retract a manual focus adjustment member of an interchangeable lens toward an infinity position after the timekeeping operation of the timer ends. .