JPH0625814B2 - Camera system - Google Patents

Description

Description: TECHNICAL FIELD The present invention receives light from a subject that has passed through a taking lens, detects a focus adjustment state of the taking lens, and performs drive control of the taking lens according to the detection result. Regarding the camera system to do.

2. Description of the Related Art Conventionally, various camera systems as described above have been proposed, but most of them perform drive control of a photographing lens based on focus detection by visible light, so that focus detection becomes difficult when a subject is dark, Therefore, the drive control of the taking lens is distorted.

However, a photoelectric conversion unit such as a CCD or a photodiode used in the light receiving unit for focus detection generally has better photoelectric conversion efficiency for infrared light than for visible light. It is also known that even a black object reflects infrared light relatively well, and that an organic object has a high reflectance for infrared light.

Therefore, if focus detection is performed using infrared light, the probability that focus detection will be possible will increase even when the subject is dark, and focus detection capability will improve.

However, when focus detection is performed using infrared light, a shift occurs compared with the case where visible light is used at the focus position of the photographing lens. This shift is caused by the chromatic aberration of the taking lens. Therefore, in the case of an interchangeable lens camera in which various interchangeable lenses are prepared for the camera, it varies depending on the type of interchangeable lens, and focus detection with infrared light is performed. If the focus of the photographic lens is adjusted based on the above, and the image is taken with visible light as it is, only a photograph with a poor focus on the subject can be obtained.

In order to eliminate this drawback, Japanese Patent Laid-Open No. 154224/1982 discloses that each interchangeable lens is provided with a signal pin having a length corresponding to the above-mentioned deviation amount, and the relationship between the signal pin and the signal pin is provided on the camera side. There is proposed a focus detection device provided with a correction mechanism that changes the position of the focus detection photoelectric conversion means depending on the combination. That is, in this proposal, when infrared light is used, the optical path length from the photographing lens to the focus detecting photoelectric conversion means is corrected by a mechanical signal or an electric signal by a signal pin of the interchangeable lens. However, since the signal pin is projected from the lens, there is a concern about its strength, and there is also a problem in the positional accuracy of the tip position of the signal pin when the interchangeable lens is attached to the camera. Further, the structure of the correction mechanism on the camera side is complicated, the manufacturing cost becomes high, and there is a drawback that the desired correction cannot be sufficiently achieved due to processing and assembling errors of the components in the correction mechanism.

Further, the method of correcting using an electric signal does not cause the above-mentioned mechanical or mechanical problems, but Japanese Patent Laid-Open No. 154224/1982 does not provide any countermeasure when the photographing lens is a zoom lens. It was not considered or suggested.

Aim This invention solves the drawbacks of the prior art proposed in Japanese Patent Laid-Open No. 154224/1982 and provides a camera system that can be sufficiently used with a zoom lens.

Summary This invention provides a detection result when focus detection is performed based on visible light mainly used for photographing, and a detection result when focus detection is performed based on auxiliary light having a wavelength different from visible light. The deviation amount of each of the focal length regions divided into a plurality is stored in the photographing lens, and the deviation amount corresponding to the focal length is output to the camera body based on the focal length set by the photographing lens. What is done is the main feature.

Examples Hereinafter, an example in which the present invention is applied to a lens interchangeable single-lens reflex camera will be described with reference to the accompanying drawings, but the focus adjustment method of the present invention is applicable to lens interchangeable cameras other than single-lens reflex cameras. Is also applicable.

First, FIGS. 1 to 7 show a first embodiment in which the focus adjusting method according to the first embodiment of the present invention is implemented. The optical and electrical arrangement of the single-lens reflex camera of this embodiment is shown. Fig. 1 schematically shows a main mirror (1) consisting of a semi-transparent mirror without wavelength selectivity, a taking lens (2) in an interchangeable lens, a pentarhythm (3), a focusing screen (4), an eyepiece The lens (5) constitutes a known finder optical system, and includes a sub (sub) mirror (6) attached to the main mirror (1), first and second reflecting surfaces (7a) and (7b) parallel to each other. The beam splitter (7) and the relay lenses (8a) and (8b) have a focus detection optical system. Here, the first reflecting surface (7a) of the beam splitter (7) has a relative reflectance (incident light
Of the light reflected by the sub-mirror (5) and incident on the beam splitter (7), most of the infrared light is reflected toward the second reflecting surface (7b). The visible light is wavelength-selective so that almost all of the visible light is transmitted, while the second reflecting surface (7b) almost completely absorbs the infrared light reflected by the first reflecting surface (7a). It is configured as a reflecting surface that reflects light. The photoelectric conversion means (9a) (9b) provided on the same substrate are a focus detection unit and a beam splitter dedicated to visible light for receiving infrared light transmitted through the first reflection surface (7a) of the beam splitter (7). Second reflective surface of (7) (7b)
Each of them has a dedicated focus detection unit for receiving infrared light reflected by the infrared light, and as shown by the broken line in Fig. 2, a common relative spectral sensitivity (maximum sensitivity) Has 1).

The outputs of the photoelectric conversion means (9a) (9b) are input to the discrimination circuit (11) and the selection circuit (12), respectively. Here, the discrimination circuit (11) discriminates the magnitude of the output of both photoelectric conversion means, and outputs a signal indicating the result to the selection circuit (12). The sorting circuit (12) is a photoelectric conversion means for visible light (9a) according to the signal from the discrimination circuit (11).
Or the output of the infrared photoelectric conversion means (9b) is output to the focus detection calculation circuit (13). And this circuit (13)
Is the amount of defocus (defocus amount) from the film surface (planned image forming surface) (10) of the focal position of the taking lens (2) at the time of focus detection and the direction of the deviation ( It outputs a signal that indicates the defocus direction, that is, whether it is in the front pinning state or the rear pinning state.
4) drives the lens drive motor (MO) based on the signal, and thereby moves the taking lens to the in-focus position.
Note that it is a so-called phase difference method that can detect both the defocus amount and the defocus direction, but this is only the defocus direction as in the fourth embodiment described later. A focus detection method, which is a so-called contrast method capable of detection, may be used, in which case the output of the photoelectric conversion means (9a) or (9b) is constantly monitored to indicate the defocus direction even while the taking lens (2) is moving. It is better to stop the driving of the photographic lens drive motor at the time when the signal cannot be obtained by the focus detection calculation circuit. The discrimination circuit (11) also discriminates whether or not the output of the visible light photoelectric conversion means (9a) and the output of the infrared photoelectric conversion means (9b) exceed a predetermined level, and any output If the predetermined level is not reached, a signal for activating the auxiliary light generation circuit (15) is output, and the infrared light LED (IR
L) is emitted.

In the above configuration, the optical distance from the taking lens (2) to the infrared relay lens (8b) or the infrared photoelectric converting means (9b) is determined by the taking lens (2) to the visible light relay lens.
(8a) or the first and second reflecting surfaces of the beam splitter (7) rather than the optical distance to the visible light photoelectric conversion means (9a)
The distance d between (7a) and (7b) is divided by the refractive index n of the optical member forming the beam splitter to be longer by d / n. Shooting lens
Of the light from the subject that has passed through (2), infrared light forms an image at a distance farther than visible light.
Even if the relay lenses (8a) and (8b) are arranged equidistant from the beam splitter (7), visible light and infrared light are converted into visible light photoelectric conversion means (9a) and infrared photoelectric conversion means (9b), respectively. Images can be imaged simultaneously on top. That is, according to this, when the visible light relay lens (8a) is arranged at a position conjugate with the film surface (10) with respect to the taking lens (2), among the light from the subject on the infrared relay lens (8b) If the infrared light of the image is formed, it means that the visible light is formed on the fill surface (10), and the focus detection of the infrared light enables the focus of the visible light on the film surface (10). It will be possible to detect. However, when various interchangeable lenses are used in a camera, since the image formation position of infrared light varies depending on the type of interchangeable lens, the above-mentioned interval d must be set to a standard value, and red It is necessary to correct the electric signal of the external photoelectric conversion means (9b).

That is, the amount of shift between the focal position of visible light and the focal position of infrared light of the taking lens (2) is due to the chromatic aberration of the taking lens (2) as described above, which is due to the optical design and focal length of the lens. It changes according to various requirements. Now, if the amount of deviation is ΔIR ₀ , then ΔIR ₀ −d / n = ΔIR, and since ΔIR in this case is a value specific to the taking lens (2), that is, the interchangeable lens having it, this Must be introduced.

In this embodiment, the interchangeable lens is provided with a data output circuit (16) for outputting a signal corresponding to the ΔIR data,
The output is input to the focus detection calculation circuit (13) on the camera side through a contact or a connection cord that conducts when the interchangeable lens is attached to the camera. The infrared light used as the basis for calculating ΔIR may be of a desired wavelength, but in this embodiment, the relative reflectance of the reflecting surface (7a) and the photoelectric conversion means (9
The wavelength of about 830 nm that maximizes the product of relative spectral sensitivity in b) is used.

FIG. 3 shows the discrimination circuit (11), the selection circuit (12), the focus detection calculation circuit (13), the motor drive circuit (14), and the auxiliary light emission circuit.
A specific circuit example of the first embodiment including (15) and the data output circuit (16) will be shown.

(IRD) is a photoelectric conversion element for monitoring infrared light provided in the photoelectric conversion means (9b) in FIG. 1, and (VSD) is a visible light monitor provided in the photoelectric conversion means (9a) in FIG. It is a photoelectric conversion element for use. These photoelectric conversion elements are operational amplifiers (OA ₁ ), (O
A ₂ ) and the logarithmic compression diode (D ₁ ) (D ₂ ) form a photometric circuit for monitoring. The outputs of the operational amplifiers (OA ₁ ) and (OA ₂ ) are compared by the comparator (AC ₁ ). If the infrared light monitor output is larger than the visible light monitor output, the comparator (AC ₁ ) output is “High”. If the visible light monitor output is larger than the infrared light monitor output, the output of the comparator (AC ₁ ) becomes “Low”. Also, operational amplifier
The output of the (OA ₁₎ a comparator (AC _3), a constant voltage source (C
Compared with the output of E ₂ ), if the monitor output of infrared light is smaller than the output of the constant voltage source (CE ₂ ), the output of the comparator (AC ₃ ) becomes “High”. Furthermore, the output of the operational amplifier (OA ₂ ) is compared with the output of the constant voltage source (CE ₁ ) by the comparator (AC ₂ ), and if the monitor output for visible light is smaller than the output of the constant voltage source (CE ₁ ). , The output of the comparator (AC ₂ ) is “Hig
h ”.

Inverter (IN ₁ ), AND circuit (AN ₁ ), (AN ₂ ), OR circuit
(OR ₁ ), (OR ₂ ) are the above-mentioned comparators (AC ₁ ), (AC ₂ ), (AC ₃ ).
Based on the output of, which one of the photoelectric conversion means for infrared light (9b) and the photoelectric conversion means for visible light (9a) is used, and a signal indicating whether or not to emit the auxiliary infrared LED (IRL) Is output. Table 1 shows the relationship between the outputs of the comparators (AC ₁ ), (AC ₂ ) and (AC ₃ ) and the output of this logic circuit.

As is clear from Table 1, if the infrared light monitor output is larger than the visible light monitor output, the infrared light receiver is inevitably used. If there is, the infrared light source is turned on. On the other hand, when the monitor output of infrared light is smaller than the monitor output of visible light, if the monitor output of visible light is a certain value or more, the visible light receiving unit is used and the light source for illumination is not turned on. If the monitor output of light is smaller than a certain value, the infrared illumination light source is turned on and the infrared light receiving section is used.

The output of the OR circuit (OR ₁ ) is the D of the D flip-flop (DF ₁ ).
To the input, the output of the OR circuit (OR ₂ ) is a D flip-flop
D flip-flops connected to the D inputs of (DF ₂ ) respectively
The (DF ₁ ), (DF ₂ ) clock terminals receive the photometry operation start signal for focus detection from the microcomputer (MCO), which will be described later. circuit (OR _1), determination signal D flip-flop from the _{(OR 2) (DF 1)} , is latched into (DF _2).

(COT) is a controller that controls the timing of the photometry operation for focus detection, (IRC) is a photoelectric conversion means for infrared rays (9b)
The focus detection CCD, (VSC) provided in the above is a focus detection CCD provided in the visible light photoelectric conversion means (9a). (S
(H) is a circuit that samples and holds the analog signal from CCD (IRC) or (VSC), (AD) is the sample and hold circuit (S
It is a circuit for AD converting the output of H).

When a pulse is sent from the output terminal (O ₃ ) of the microcomputer (MCO) to the terminal (ST) of the controller (COT) to start the photometric operation for focus detection, the controller (COT) sends an analog switch (AS). ₅ ) Output a reset pulse to turn on (AS ₆ ) from the terminal (φ _R ).
Due to the conduction of (AS ₅ ) (AS ₆ ), CCD (IRC) (VSC) is a constant voltage source (CE
It is charged to the output potential of ₅ ) via the terminal (IAD) (VAD).
The reset pulse from this terminal (φ _R ) is also input to the set terminal of the flip-flop (FF ₁ ).
The flip-flop (FF ₁ ) is set by the pulse from (φ _R ), and the Q output of the D flip-flop (DF ₁ ) becomes “H”.
If it is “igh”, the output of the AND circuit (AN ₃ ) becomes “High”, the transistor (BT ₁ ) becomes conductive, and the infrared light emitting diode (IRL) for lighting turns on. CCD (IRC), ( VSC) accumulates the electric charge output from those light receiving parts (individual photoelectric conversion elements), and outputs the potential corresponding to the accumulated electric charge from terminals (IAD) and (VAD). (DF ₂ )
If the Q output of is high (when CCD (IRC) for infrared is used), the analog switch (AS ₄ ) becomes conductive and CCD (I
The potential from the output terminal (IAD) of RC) is input to the comparator (AC ₄ ). On the other hand, if the output of the D flip-flop (DF ₂ ) is “High” (when the CCD (VSC) for visible light is used), the analog switch (AS ₃ ) becomes conductive and the CCD (V
The potential from the output terminal (VAD) of SC) is input to the comparator (AC ₄ ).

The comparator (AC ₄ ) compares the potential corresponding to the accumulated charge from the terminal (IAD) or (VAD) with the output potential of the constant voltage source (CE ₃ ), and controls the “High” signal if they match.
Send to (COT). Then, the controller (COT) outputs a transfer pulse from the terminal (φ _T ) and transfers the electric charges accumulated in the CCD (IRC) and (VSC) to the transfer gate. The transfer pulse is also sent to the reset terminal of the flip-flop (FF _1), the flip-flop (FF ₁₎ is a light emitting diode for illumination is reset
(IRL) goes off. Then, after that, from the output terminals (IRS) and (VSS) of CCD (IRC) and (VSC), transfer clocks (φ ₁ ), (φ ₂ ),
The charges accumulated based on (φ ₃ ) are sequentially output,
At this time, the Q output of the D flip-flop (DF ₂ ) is "Hig
If h ”, the analog switch (AS ₁ ) is conducting and the terminal
Infrared light reception output from (IRS) sample and hold circuit
(SH) while the output of D flip-flop (DF ₂ ) is “High”, analog switch (AS ₂ ) conducts and the visible light output from terminal (VSS) is sampled.・ Input to the hold circuit (SH). Controller (COT)
Outputs a pulse for sampling and holding from the terminal (φ _S ) and then outputs a pulse for starting A / D conversion from the terminal (φ _C ). Then, the AD converter (AD) AD converts the output of the sample hold circuit (SH). Then the controller (C
OT) outputs a pulse from the terminal (TR) to the input terminal (i ₄ ) of the microcomputer (MCO), and A-to the input port (IP ₁ ) of the microcomputer (MCO). The A / D converted data is output by the D converter (AD). After that, the operations of outputting the accumulated charge, sampling and holding, A / D conversion, and data transfer described above are repeated, and when the transfer of data equal to the number of light receiving parts of the CCD (IRC) and (VSC) is completed, the controller The (COT) sends a data transfer completion pulse from the terminal (EN) to the input terminal (i ₆ ) of the microcomputer (MCO) to stop the operation.

In this embodiment, a photoelectric conversion device for monitoring (IRD), (VSD)
However, even if such a monitor photoelectric conversion element is provided, it is possible to switch which CCD output is used and to determine whether to turn on the lighting light emitting diode. . That is, before the photometry operation for focus detection, charges are accumulated in CCD (IRC), (VSC) for a certain period of time, and the outputs of terminals (IAD), (VAD) based on the accumulated charges are discriminated in FIG. It is determined in the same manner as the circuit for the focus detection, and the determination result is determined by the D flip-flop (D
Latch to F ₁ ), (DF ₂ ).

Next, the remaining circuit portion in FIG. 3 will be described. (BA) is a power supply battery, (MS) is a switch that is closed in the first step of pressing the release button (not shown), and when this switch (MS) is closed, the inverter (IN ₂ ) The output becomes "High", and the microcomputer (MCO) starts focus detection and focus adjustment operations, while the measurement, calculation, and display circuit for exposure.
(LM) also starts operation. Also, a microcomputer
(MCO) turns the terminal (O ₁ ) to “H” when the switch (MS) is closed.
Set it to "igh" and set the output of the inverter (IN ₃ ) to "Low" to make the transistor (BT ₂ ) conductive and supply power from the power supply line (Vcc). The switch (RS) is the first button when the release button is pressed. This is a switch that is closed in two stages, and when this switch is closed, the output of the inverter (IN ₄ ) becomes “High.” At this time, the exposure control circuit (EC) is in the ready state and the inverter (I
If the output of N ₀ ) is “High”, the output of the AND circuit (AN ₀ ) becomes “High”, the microcomputer (MCO) stops the focus detection and focus adjustment operations, and the exposure control operation stops. Wait to do. When the switch (RS) is closed, the exposure control circuit (EC) performs the exposure control operation based on the exposure control value from the metering / calculation / display / circuit (LM).・ Computer (MCO) input terminal
Send a “High” operation completion signal to (i ₄ ). This signal becomes "Low" when the charge of the exposure control mechanism is completed and the reference of the exposure control operation is completed.

The display unit (DP) displays front pin, rear pin, and focus based on the data from the output port (OP ₁ ) of the microcomputer (MCO). Motor drive circuit (MDR) is an output port
The motor (MO) is rotated normally or reversely based on the data from (OP ₂ ), and the lens is moved to the in-focus position via the lens drive mechanism (LDR). Also, (EN) is the lens drive mechanism (LDR)
Is an encoder for monitoring the amount of rotation of the lens drive mechanism, and outputs one pulse each time the lens drive mechanism (LDR) rotates by a predetermined amount. (IF) is a microcomputer (MCO) terminal
This is an interface circuit that takes in the data necessary for lens driving from the lens data output circuit (LDO) with a pulse from (O ₂ ). From the data output circuit (LDO) of the interchangeable lens attached to the camera, data ΔIR showing the amount of deviation between the infrared focus position and the visible light focus position, and the predetermined value of the lens drive mechanism (LDR). Data K of the ratio of the movement amount of the lens to the rotation amount (a predetermined number of pulses from the encoder (EN)) is sent.

Although the circuit of FIG. 3 has been schematically described above, in FIG. 3, the portions corresponding to the circuits (11) (12) (14) (15) (16) of FIG. 1 are indicated by alternate long and short dash lines or (). , (LM) (EC) (LDR) (E
The rest except N) corresponds to circuit (13).

Next, a specific example of the interface circuit (IF) and a specific example of the data output circuit (LDO) of FIG. 3 will be described.

In Fig. 4, the terminals of the microcomputer (MCO)
When the “High” pulse is input from (O ₂ ), the flip-flop (FF ₅ ) is set and the D flip-flop (DF ₅ ) is generated at the next rising of the clock pulse from the oscillator (OSC).
Q output becomes high. This allows AND circuit
Since (AN ₁₀ ) is opened, the clock pulse from the oscillator (OSC) is input to the ring counter (CO ₁ ), and the ring counter (CO ₁ ) sequentially outputs from the rising edge of the clock pulse to the next rising edge ( b ₀ ), (b ₁ ) …… (b ₉ ), (b ₀ ), (b ₁ ) ……
Set (b ₉ ) to “High”. On the other hand, the Q output of the D flip-flop (DF ₅ ) is the lens side data output circuit (LD
It is also transmitted to O) via terminals (J ₁ ) and (J ₁ ′). The 5-bit shooting distance input from the shooting distance output section (DD) via the analog switches (AS ₁₅ ) to (AS ₁₉ ) is input to the latch circuit (LA ₃ ) for rising the Q output to “High”. Data is latched. After a delay time of the delay circuit (DL), the output of the delay circuit (DL) becomes “High”, the output of the inverter (IN ₁₀ ) becomes “Low”, and the analog switch (AS)
₁₀ ) to (AS ₁₄ ) are turned on and the 5-bit focal length data from the focal length data output unit (FD) is input to the latch circuit (LA ₃ ).

Focal length data output unit (FD) and shooting distance data output unit
Each of the (DD) is composed of a code plate, and the total 10-bit data is an IC circuit with 6 terminals (circuit part surrounded by the one-dot chain line in FIG. 4) with the above structure. Can be entered. Further, the example of FIG. 4 shows an example of the interchangeable lens in which the above-mentioned data ΔIR, K changes depending on the focal length and the photographing distance, and therefore the above-mentioned two data are required.

The shooting distance data from the latch circuit (LA ₃ ) and the focal length data from the analog switches (AS ₁₀ ) to (AS ₁₄ ) are input to the decoder (DE ₃ ) and converted into 6-bit data. . Then, this data is input to the lower 6-bit address terminal of the ROM (RO).

In addition, the Q output of the D flip-flop (DF ₅ )
When (J ₁ ′) becomes “High”, the clock pulse from the oscillator (OSC) input via the pin (J ₂ ′) passes through the AND circuit (AN ₁₄ ) and the ring counter (CO ₁ ) Input to a ring counter (CO ₂ ) with the same configuration as.

The terminal (b ₁ ) of the ring counter (CO ₁ ) in Fig. 4 is "High".
To become the terminal (J _3), the (J ₃ ') via the output Q _1, Q ₂ of the signal "High" is input to the counter (CO ₃₎ counter (CO ₃₎ is "01". The output of this counter (CO ₃ ) is input to the upper 2 bits of the address pin of ROM (RO),
Is “01 ××××××” (× ... × is the output of the decoder (DE))
Address is specified, and ΔIR data corresponding to the focal length and the shooting distance is output. Then, the ring counter (C
When the (O ₂ ) terminal (L ₂ ) rises, this ΔIR data is fetched in parallel by the shift register (SR ₂ ) .After that, the ΔIR data is sequentially output terminal (OUT ), And is taken into the shift register (SR ₁ ) in the camera side interface circuit (IF) via the terminals (J ₄ ′) and (J ₄ ). This shift register (SR
₁ ) is designed to fetch data at the falling edge of the clock, so for 8-bit data, pin (b ₂ ) is "High".
It is taken into the shift register (SR ₁ ) from the falling edge of the clock pulse at the time of to the falling edge of the clock pulse when the pin (b ₉ ) is “High”.

Then, when the terminal (b ₁ ) rises to “High” for the second time, the Q output of the D flip-flop (DR ₇ ) becomes “High”, and at this time, the output of the D flip-flop (DF ₈ ) becomes “High”. High "since the aND circuit (AN ₁₁₎ from the terminal (b _0)" are output pulses of the High ", at the rising, the data from the latch circuit (LA ₁₎ to the shift register (SR ₁₎ ΔIR
Is latched. Then, next, when the terminal (b ₁ ) of the ring counter (CO ₁ ) becomes “High” for the second time, the counter (CO ₃ ) is transferred from the terminals (J ₃ ), (J ₃ ′) to this “High”. In response to the signal of "", the outputs Q ₁ and Q ₀ become "10", and the ROM (RO) is specified with the address "10xxxxxxx" and the K data corresponding to the focal length and the shooting distance. Is output. This data is taken into the shift register (SR ₂ ) at the rising edge of the terminal (L ₂ ) of the ring counter (CO ₂ ), and thereafter, one bit at a time (J ₄ ′), in synchronization with the rising edge of the clock pulse. (J ₄₎ in synchronism is input to the fall of the clock pulse to the shift register (SR ₁₎ in the fourth diagram of a camera-side interface circuit (IF) via the incorporated into the shift register (SR _1),
Between the falling edge of the clock pulse when the terminal (b ₂ ) is “High” and the falling edge of the clock pulse when the terminal (b ₉ ) is “High”, 8-bit data K is stored in the shift register (SR ₁ ).

Next, when the terminal (b ₀ ) of the ring counter (CO ₁ ) rises to “High”, the Q output of the D flip-flop (DF ₈ ) becomes “Hig.
The output of the AND circuit (AN ₁₂ ) outputs the “High” pulse from the terminal (b ₀ ) and the shift register (S
The data K fetched by R ₁ ) is latched by the latch circuit (LA ₂ ). The output of the AND circuit (AN ₁₂ ) is the OR circuit (OR
₁₀ ) via a flip flop (FF ₅ ), a D flip
Flop (DF ₅ ), (DF ₆ ) (DF ₇ ), (DF ₈ ), ring counter (C
It is sent to the reset terminal of O ₁ ) and these circuits are reset at the fall of the output of the AND circuit (AN ₁₂ ). Also,
Due to this reset, the signal that the Q output of the D flip-flop (DF ₅ ) falls to “Low” is sent to the counter (CO ₂ ) via the terminals (J ₁ ), (J ₁ ′) and the OR circuit (OR ₁₁ ), is sent to the reset terminal of the (CO _3), these counters _{(CO 2), (CO 3} ) is also reset.

By repeating the above operation, the data of ΔIR, K corresponding to the state of the shooting lens is sequentially captured by the interface circuit (IF) on the camera side, and the input port (IP ₂ ), ( IP ₃ ) to Micro Computer (MCO)
Be taken into. In addition, (PO ₁ ) and (PO ₂ )
In the reset circuit, when the transistor (BT ₂ ) shown in FIG. 3 is turned on and power is supplied from the power supply line (Vcc), each reset signal is output. These reset signals are output via OR circuits (OR ₁₀ ) and (OR ₁₁ ), respectively, and are flip-flops (FF ₅ ), D flip-flops (DF ₅ ), (DF
₆ ), (DF ₇ ), (DF ₈ ), and counters (CO ₁ ), (CO ₂ ), (CO ₃ ) are reset at the falling edge.

FIG. 5 is a data output circuit of an interchangeable lens in which ΔIR and K change according to only one of the focal length and the shooting distance.
(LDO) Examples are shown. The same members or circuit elements as those in FIG. 4 are designated by the same reference numerals. In the case of this interchangeable lens, the upper 2 bits of the ROM (RO) are addressed by the output of the counter (CO ₃ ), the least significant bit is connected to ground, and the remaining 5 bits are the focal length data output (FD). Alternatively, it is addressed by data from the shooting distance data output unit (DD). The rest of the circuit is the same as in FIG.

FIG. 6 shows an embodiment of a data output circuit (LDO) of an interchangeable lens having a fixed ΔIR, K. In this embodiment, the diode array (DIA) is used instead of the ROM, and when the terminal (Q ₀ ) of the counter (CO ₃ ) becomes “High”, the diode array (Q ₀ ) connected to this terminal (Q ₀ ). DIA) ΔIR data is output, and when the terminal (Q ₁ ) becomes “High”, the K array diode (DIA) data connected to this terminal (Q ₁ ) is output. Other parts are the same as in FIG.

Next, the operation of the circuit shown in FIG. 3 will be described based on the flow chart of the microcomputer (MCO) shown in FIG. The microcomputer (MCO) is in a low power consumption and inactive "HALT" state while the switch (MS) is opened. When the switch (MS) is closed, the “High” output of the inverter (IN ₂ ) is input to the interrupt terminal (it), and the microcomputer (MCO) starts operation from step # 0. In step # 0, the terminal (O ₁ ) is set to “High” and the output of the inverter (IN ₃ ) is set to “Low” to make the transistor (BT ₂ ) conductive. Therefore, power supply by the power supply line (Vcc) is started. Then, in step # 1, the switch (RS) is closed and the inverter (IN ₄ )
The output becomes "High", to determine whether the input terminal (i ₃₎ is set to "High", the input terminal (i ₃₎ will be described later since the exposure control operation if "High"# Go to step 41. If the terminal (i ₃ ) is “Low”, a “High” pulse is output to the output terminal (O ₃ ) to start the photometry operation for focus detection described above. A "High" pulse is output to O ₂ ) to start the operation of reading the data ΔIR, K from the interchangeable lens described above.

Next, in step # 4, wait until the input terminal (i ₄ ) becomes “High”, and when (i ₄ ) becomes “High”, the input port (IP ₁ )
Controller (COT) data from (CCD (VS
(C) or (IRC) value obtained by A / D conversion of accumulated charge by one light receiving portion) It is determined whether the terminal (i ₆ ) is “High”. If it is "Low", the process returns to the step # 4 to fetch the next data. On the other hand, if it is determined that the input terminal (i ₆ ) is “High” in step # 6, the CCD
A− of accumulated charge by all light receiving parts of (VSC) or (IRC)
Since the acquisition of the D conversion value is completed, the process proceeds to step # 7. In step # 7, it is determined again whether the switch (RS) is closed and the input terminal (i ₃ ) is "High". If (i ₃ ) is “High”, the process proceeds to step # 41.

If the input terminal (i ₃ ) is not "High" in step # 7,
Move to step # 8, and input port (IP ₂ ) to ΔIR
Data, and then K data from the input port (IP ₃ ). Then, in step # 10, the input port (I
The focus shift amount and direction are calculated based on the data acquired from P ₁ ). This calculation is performed, for example, in Japanese Patent Laid-Open No. 57-4
The calculation shown in No. 5510 may be performed. Then, in step # 11, it is determined whether the input terminal (i ₅ ) is “High”, and if it is “High”, the infrared CCD (IRC) is used.
Since Δl (the shift amount and direction of the focus) is calculated using the output of, the data ΔIR of the shift amount of the in-focus position between the infrared light and the visible light, the rotation amount of the lens driving mechanism and the movement of the lens. Based on the quantity ratio data K, K · (Δl-ΔIR)
= N is calculated, and the number of pulses N to be input from the encoder (EN) is calculated. On the other hand, if it is determined in step # 11 that the input terminal (i ₅ ) is not “High”, it means that the CCD (VSC) for visible light has been used. Therefore, ΔIR data is not used and K · The encoder calculates Δl = N
Calculate the number of pulses N to be input from (EN).

In the step of # 14, the focus matching state is displayed, and the same input terminal (i ₃ ) is discriminated as described above.
In the step, it is determined whether the pulse number N is 0 or not. If N is 0, the process proceeds to step # 38 described later, while if N ≠ 0, the process proceeds to step # 17, where
N is set in the register M in the computer (MCO). Then, the motor (MO) is caused to start normal rotation or reverse rotation in accordance with the focus shift direction, and data P ₀ is set in the register P in the microcomputer (MCO). And encoder
A pulse is input from (EN) to determine whether the input terminal (i ₂ ) has become “High”. If “Low”, go to step # 27. If “High”, go to step # 21. Move to.

In step # 27, the switch (RS) is closed to determine whether the input force terminal (i ₃ ) is “High”. If it is “High”, the exposure control operation is started. After stopping the rotation of (MO) and resetting a flag JF in the microcomputer described later, the process proceeds to step # 41.
On the other hand, if the input terminal (i ₃ ) is "Low", the step # 28 subtracts 1 from the content of the register P to determine whether the content of P is 0 or not. If (P) ≠ 0, it is determined in step # 30 whether the flag JF is 0, and if 0, # 20
Return to and determine whether the input terminal (i ₂ ) is “High”. If it is "Low", the process proceeds to step # 27 again. Therefore, the input terminal (i ₂₎ is repeated the above operations until the "High", unless become terminal (i ₂₎ is "High" until the (P) = 0 (a predetermined time), a motor ( M
For some reason (for example, the lens is moved to the closest position) even if (O) is driven, the lens drive mechanism cannot move anymore, so rotate the motor (MO) in step # 33. It is stopped, a warning is displayed, the flag JF is reset, and the process proceeds to step # 38.

When it is determined in step # 20 that the input terminal (i ₂ ) is "High", in step # 21 the register M
The content N of 1 is subtracted from 1 to determine whether or not the content of M becomes 0. If (M) ≠ 0, the flag JF is set to 1, the data of P ₀ is set to the register P, and the input terminal (i ₂ )
Discriminates whether or not is “Low”. And “H
If it is still "igh", the process moves to the above-mentioned step of # 27 and moves to the flow for counting the fixed time. In this case, since the flag JF is 1, the process returns to the step of # 25. Also in this case, (P) If = 0, it means that the lens has been driven to the closest position, so the flow starts from # 33, the motor is stopped and a warning is displayed, and then the flag JF is reset and the step of # 38. Move to.
Then, when it is determined in step # 25 that the input terminal (i ₂ ) has become “Low”, the flag JF is reset and
Return to step 9.

It should be noted that although the value of the register M is decremented by 1 only when it is determined that the input terminal (i ₂ ) has become “High”, when the input terminal (i ₂ ) has become “Low” Also, 1 is subtracted from the content of the register M to determine whether the content of M has become 0. When (M) = 0, the process proceeds to step # 36, and the value of N is twice the value of this embodiment. If the value is calculated, the rising and falling edges of the pulse from the encoder (EN) will be counted, and the focus adjustment accuracy of the lens will be improved.

If (M) = 0 is determined in step # 22, the lens has been moved to the in-focus position, the motor (MO) is stopped in step # 36, and the focus is displayed in step # 37. Do.

In step # 38, it is determined whether the switch (MS) is closed and the input terminal (i ₇ ) is "High". And the force terminal
If (i ₇ ) is "High", the operation returns to step # 1 and the same operation as described above is repeated. If (i ₇ ) is "Low", the display is turned off and the terminal (O ₁ ) is set to “Low” to stop the power supply from the power supply line (Vcc) by the transistor (BT ₂ ) and the microcomputer (MCO) becomes “HALT” state. If it is determined that the switch (RS) is closed, the process waits for the input terminal (i ₁ ) to become “High” in step # 41. When the exposure control operation is completed and a "High" pulse is input from the exposure control circuit (EC) to the input terminal (i ₁ ), the process proceeds to step # 38.

Next, a modification of the first embodiment will be described. First,
The photoelectric conversion means for focus detection may be one that outputs a signal corresponding to the instantaneous light intensity, such as a photodiode array, instead of an integral type such as CCD. Also, Δ
For the calculation of l, an example in which digital operation is performed based on the digital value obtained by A / D converting the photoelectric conversion output has been shown. However, analog operation is performed based on the analog output, and the operation result is A / D converted to Motor control and display may be performed based on digital values.

Fig. 8 shows that auxiliary light emission control is performed based on the outputs from the CCD (IRC) and (VSC) output terminals without special provision of monitor photoelectric conversion elements (IRD) and (VSD). A second embodiment of the present invention for determining which of the CCD outputs is used is shown.

The counter (CO ₁₀ ) is reset by the reset pulse (φ _R ), counts time based on the clock pulse (φ ₁ ), and outputs the pulse from the carry terminal after 40 msec, for example. When this pulse is output, the terminal (IA
The output of D), the output of (VAD) and the output of the constant voltage source (CE ₁₀ ) are the comparator (AC ₁₀ ) (AC ₁₁ ), (AC ₁₂ ), AND circuit (AN
₂₁ ), (AN ₂₂ ), and the result of the judgment with the inverter (IN ₂₀ ) is D
Latched in flip-flops (DF ₂₀ ) and (DF ₂₁ ).

Where IAD <VAD, IAD <CE ₁₀ or IADVAD, VAD <CE ₁₀
Output of AND circuit (AN ₂₁ ), (AN ₂₂ ), both
When ow ”, the Q outputs of D flip-flops (DF ₂₀ ) and (DF ₂₁ ) both become“ Low ”, the output of the OR circuit (OR ₂₁ ) remains“ Low ”and the infrared light emitting diode (IRL) No light emission, in this case CCD (IRC) or (VSC) at the time of 40msec
The output of (CE ₁₀ ) has reached the output of (CE ₁₀ ), so even if the infrared light emitting diode (IRL) does not emit light within a certain time (for example, 80 m
The charge to the CCD will be completed in sec).

On the other hand, in the case of VADCE ₁₀ in IAD <VAD in IADCE ₁₀ or IADVAD, the output of the AND circuit (AN ₂₁₎ or (AN ₂₂₎ is "Hi
When the counter (CO ₁₀ ) outputs a pulse, the output of the D flip-flop (DF ₂₀ ) or (DF ₂₁ ) becomes “High” and the output of the OR circuit (OR ₂₁ ) It goes to “High.” This turns on the light-emitting diode (IRL) to illuminate the infrared.The reason for this infrared illumination is that if the CCD is continuously accumulated without illumination, the accumulation is performed. This is because it takes a certain time (80 msec) or more and the measurement takes too long.

When the output of the terminal (IAD) or (VAD) reaches the level of the constant voltage source (CE ₁₁ ), the output of the comparator (AC ₁₃ ) or (AC ₁₄ ) becomes “Hig.
It is inverted to "h" and a "High" pulse is output from the one-shot circuit (OS ₁₀ ) or (OS ₁₁ ). When this pulse is output, both flip-flops (FF ₁₀ ) and (FF ₁₁ ) are reset. In this state, the gates of the AND circuits (AN ₂₃ ) and (AN ₂₄ ) are both open, so the above-mentioned pulse passes through the AND circuit (AN ₂₃ ) or (AN ₂₄ ). ₁₀ )
Or it is given to the set terminal of (FF ₁₁ ) and one of the flip
The flop is set. Flip Flop (FF
_{When (10} ) is in the set state, the gate of the AND circuit (AN ₂₄ ) is closed, and when the flip-flop (FF ₁₁ ) is in the set state, the gate of the AND circuit (AN ₂₃ ) is closed. This state is maintained until the reset pulse from O ₃ ) is input. Flip-flop (FF ₁₀ ), (FF
_{When one of 11} ) is set, the output of the OR circuit (OR ₂₃ ) becomes “High”, this signal is sent to the controller (COT) and the transfer pulse (φ _T ) is output.

The Q output of the flip-flop (FF ₁₀ ) is the analog switch (AS ₁ ), and the Q output of (FF ₁₁ ) is the analog switch (AS ₂ ).
Since it is connected to the control terminal of, the signal of which the accumulated charge of the CCD reaches the output of the predetermined value (CE ₁₁ ) is adopted as the signal for focus detection. That is, the one in which the accumulated charge of the CCD reaches the predetermined value first is adopted as the signal for focus detection.

The output of the OR circuit (OR ₂₃ ) is also input to the one sailboat circuit (OS ₁₂ ), and when the output of the OR circuit (OR ₂₃ ) becomes “High”, the “High” pulse is output from the one shot circuit (OS ₁₂ ). D flip-flop output via OR circuit (OR ₂₄ )
Reset (DF ₂₀ ), (DF ₂₁ ) and turn off the light emitting diode (IRL) if it is on.

The counter (CO ₁₁ ) is reset by a reset pulse (φ _R ), counts the clock pulse (φ ₁ ) and outputs the pulse after a fixed time (for example, 80 msec). If the outputs of the comparators (AC ₁₃ ) and (AC ₁₄ ) are both “Low” at the time when the pulse is output from this counter (CO ₁₁ ), it will go through the OR circuit (OR ₂₂ ) and AND circuit (AN ₂₃ ). pulse from the counter (CO ₁₁₎ Te is input to the set terminal of the flip-flop (FF _10), flip-flop (FF ₁₀₎ is in the set state. As a result, the transfer pulse (φ _T ) is output, and the output of the infrared CCD (IRC) is adopted as the signal for focus detection. In this case, the accumulated charge does not reach the predetermined value within 80 msec, but focus detection is possible, so integration is forcibly stopped in 80 msec in order to shorten the time. Furthermore, in this case, the light emitting diode (IR
Since the output of CCD for infrared light (IRC) is higher than the output of CCD for visible light (VSC) because L) is emitting light, the output of CCD for infrared light is used. Is configured to.

FIG. 9 shows a third embodiment of the present invention. FIG. 10 is a flowchart showing the operation of the microcomputer (MCO) adapted to this embodiment.

In addition, in this flowchart, a part of FIG.
Some are shown in more detail.

In FIG. 9, a photoelectric conversion element for monitoring is not provided, and furthermore, as the photoelectric conversion means, only a CCD (IRC) that receives infrared light is provided. Further, the infrared light emitting diode (IRL) for illumination once calculates Δl based on the output of the CCD (IRC), and based on the calculation result, there is no reliability in the calculated Δl due to insufficient contrast. The light is emitted when it is determined.

The operation of the third embodiment will be described below with reference to FIG.

Step # 10 is the same as the flow chart in Fig. 7, and the microcomputer C (MCO) has an infrared C
The output of CD (IRC) is taken in and Δl is calculated. Therefore, this Δl is data of the amount of deviation from the focus position of infrared light. Then, in step # 51, it is determined whether or not the contrast data obtained in the calculation process in step # 10 is a certain value or more. When the contrast is smaller than the fixed value, the process proceeds to step # 52, and since the value of Δl is unreliable, a warning is displayed. Then, in step # 53, the microcomputer
(MCO) output terminal (O ₄ ) Determine whether it is “High”. If the terminal (O ₄ ) is “High”, it means that the light emitting diode (IRL) is once made to emit light and Δl is calculated. Therefore, even if the light emitting diode is made to emit light again and Δl is recalculated, Δl is still Since there is a high probability that unreliable data will be calculated, there is no choice but to move to step # 12.

On the other hand, if the output terminal (O ₄ ) is not “High”, the output terminal (O ₄ )
To "High" and return to step # 1 again to CCD (IRC)
Is measured and Δl is recalculated.
Here, if the output terminal (O ₄ ) is “High”, the reset pulse (φ _R ) is applied to the set terminal of the flip-flop (FF ₂₀ ) via the AND circuit (AN ₃₀ ) in FIG. Sent, the flip-flop (FF ₂₀ ) is set, the light emitting diode (IRL) starts to emit light, and the transfer pulse (φ _T ) is flipped through the AND circuit (AN ₃₁ ) and the OR circuit (OR ₃₀ ). The flop
(FF ₂₀ ) to the reset terminal and flip-flop (F
F ₂₀ ) is reset and the light emitting diode (IRL) goes out.

Next, in step # 12, the data of the motor rotation speed and the rotation direction (N is positive and negative) are calculated based on the data of Δl, ΔIR, and K, and the same steps as # 14 to # 16 in FIG. 7 are performed. After passing #
Move to step 55. Steps # 55 to # 58 are the 7th
The steps # 17 and # 18 in the figure are shown in more detail. In step # 55, the rotation speed data | N | is set in the register M, and in step # 56 it is determined whether N> 0. N> 0
In the case of, the forward rotation of the motor is started, and in the case of N <0, the reverse rotation is started, and the process proceeds to step # 19 in FIG.

When the focus adjustment operation is completed in steps # 16, # 35, and # 37, the process moves to step # 59 to determine whether the switch (RS) is closed. Determine if switch (MS) is open and terminal (i ₇ ) is “Low”. If (i ₇ ) does not become “Low”, the above operation is repeated. When (i ₇ ) becomes “Low”, the display disappears and the output terminals (O ₁ ) and (O ₄ ) become “Low”. "" And the microcomputer (MCO) enters the "HALT" state. Therefore, in this flowchart, once the focus adjustment operation is completed, the switch (MS) is not opened and closed again until new focus adjustment is performed.

When it is determined that the switch (RS) is closed and the terminal (i ₃ ) is “High”, the terminal (O 3
₄ ) to “Low” and the exposure control operation is completed
Wait for (i ₁ ) to become “High”. When it becomes “High”, the switch (MS) is closed and it is judged whether the terminal (i ₇ ) is “High” or not. If the focus adjustment operation is performed again by moving to step 1 and it is "Low", then the operation proceeds to step # 61 and the operation is ended. It should be noted that in FIG. 9, when the switch (RS) is closed, the output of the AND circuit (AN ₀ ) changes to "Hig".
Since it becomes "h", a "High" pulse is output from the one-shot circuit (OS ₂₀ ) and flip-flops are sent via the OR circuit (OR ₃₀ ).
Flop (FF ₂₀ ) is reset and light emitting diode (IRL)
Is turned off.

FIG. 11 is a modification of the flowchart of FIG. # 51
It is determined that the contrast is insufficient in the step of
If it is determined in step # 53 that Δl is calculated by causing the light emitting diode (IRL) to emit light once, the light from the light emitting diode (IRL) is reflected from the subject and returned to the CCD (IRC). probability not been high, this case, the subject has a high probability of existing in infinite position of the ability of the imaging lens, in this case, as the rotation speed data of the motor, this ensures that the infinity position data N _m And set to step # 14.

In the case of the third embodiment of FIG. 9, the focus detection optical system is
As long as the CCD (IRC) receives only infrared light,
For example, in FIG. 1, the photoelectric conversion means (9a) may be simply removed, or an infrared filter may be used instead of the beam splitter (7), and the infrared light passing through it may be converted into a CCD (IRC) by a relay lens. You may make it relay.

What has been described above is an embodiment of the above-described one embodiment of the focus adjusting method of the present invention. Next, referring to FIG. 12, an embodiment of the other embodiment of the focus adjusting method of the present invention will be described. explain.

The focus detection method of the embodiment shown in FIG. 12 is a so-called contrast detection method, and is disclosed in, for example, Japanese Patent Laid-Open Nos. 57-72110 and 57-8.
As disclosed in Japanese Patent No. 8418, the focus detection calculation circuit (13 ') in this case outputs only a signal indicating the direction of deviation of the focal position of the photographing lens from the film surface. That is, in the so-called front pin state, the signal of “High” is output to the terminal (a),
In the so-called rear-pin state, a “High” signal is output to the terminal (c), and in the focused state, a “High” signal is output to the terminal (b).
3 '), and these "High" signals cause the display device (DP) in the viewfinder of the camera to display each state. The terminals (a) and (c) of the circuit (13 ') are AND circuits, respectively.
Connected to one input of (AN ₁₀ ) (AN ₁₁ ), pin (b)
Is connected to the inverting input of the AND circuit (AN ₁₀ ) (AN ₁₁ ). The motor drive circuit (MDR) is connected to the output of the AND circuit (AN ₁₀ ), and is connected to the AND circuit (A ₁₀ ) via the OR circuit (OR ₁₀ ).
The output of the OR circuit (OR ₁₀ ) is connected to the output of N ₁₁ ), and when the output of the AND circuit (AN ₁₀ ) is “High”, for example, the motor (MO) is rotated in the forward direction to retract the shooting lens. When is "High", the motor (MO) is rotated in reverse to extend the taking lens. When the output of the AND circuit (AN ₁₀ ) or the OR circuit (OR ₁₀ ) does not become “10,000” high, the drive of the motor (MO) by the motor drive circuit (MDR) stops.

The one-shot circuit (OS ₁₀ ) has "Hig
When the "h" signal is output, the flip-flop (FF ₁₀ )
Generates a pulse that sets
(AN ₁₂ ) Flip-flop (F
The Q output of F ₁₀ ) becomes "High". Also, one-shot circuit
The pulse from (OS ₁₀ ) resets the counter (CO ₁₀ ) that counts the pulse from the encoder (EN). The digital comparison circuit (DC) compares the output of this counter with the data output ΔIR of the data output circuit (LDO) of the interchangeable lens that is output from the data reading circuit (DR). Inverts the output connected to the other input of the circuit (AN ₁₂ ) from “High” to “Low”. In addition,
The output of the AND circuit (AN ₁₂ ) is connected to the other input of the OR circuit (OR ₁₀ ) whose one input is connected to the input of the AND circuit (AN ₁₁ ). Also, the output of the comparison circuit (DC) is "Hig
When “h” changes to “Low”, the one-shot circuit (OS ₁₁ ) resets the flip-flop (FF ₁₀ ).

According to this embodiment, is started focus detection by infrared, Assuming that the signal circuit (13 ') of the terminal (a) to "High" is outputted, the output of the AND circuit (AN ₁₀₎ is "High ", The motor (MO) rotates in the normal direction, and the taking lens is retracted. As a result, when the focus position of the shooting lens due to infrared light matches the film surface, which is the planned image formation surface, the terminal
The output of (a) becomes “Low” and the output of terminal (b) becomes “High”.
become. Then, the one-shot circuit (OS ₁₀ )
Receives the output of (b), outputs a pulse, the flip-flop (FF ₁₀ ) is set, and the Q output becomes “High”.
The outputs of the AND circuit (AN ₁₂ ) and OR circuit (OR ₁₀ ) also become “High”, and the motor drive circuit (MDR) reverses the motor (MO),
The taking lens is extended from the position in focus with the infrared light. At this time, the number of pulses output from the encoders (EN) corresponding to the amount of reverse rotation of the motor (MO) is the counter (CO ₁₀ )
The output of the counter (CO ₁₀ ) is compared with the signal of ΔIR read by the reading circuit (DR) by the comparison circuit (DC). Then, when the output of the counter (CO ₁₀ ) matches this ΔIR signal, the output of the comparison circuit (DC) changes to “Hig
Since it is inverted from “h” to “Low”, the outputs of the AND circuit (AN ₁₂ ) and OR circuit (OR ₁₀ ) are both “Low”. At this time, the output of the AND circuit (AN ₁₀ ) is also “Low”. The driving of the motor (MO) by the motor drive circuit (MDR) stops, that is, the photographing lens reaches the in-focus position for visible light and stops, and the photographing lens by focus detection with infrared light. The focus adjustment to the in-focus position with respect to visible light of is completed by flipping the pulse output from the one-shot circuit (OS ₁₁ ) by inverting the output of the comparison circuit (DC) from “High” to “Low”. Since the flop (FF ₁₀ ) is reset and its Q output is inverted to "Low", the AND circuit
(AN ₁₂ ) is completely closed.

Contrary to the above, the circuit (1
3 ') outputs a "High" signal to the circuit (c), the AND circuit (AN ₁₁ ) and OR circuit (OR ₁₀ ) both output "High", and the motor drive circuit (MDR) (MO) is reversed and the shooting lens is extended. Then, when the photographing lens reaches the focus position for infrared light, the output of the terminal (c) becomes "Low" and the output of the terminal (b) becomes "High". As a result, the output of the AND circuit (AN ₁₁ ) becomes “Low”, but the flip-flop (FF ₁₀ ) turns into the one-shot circuit (OS
It is set by the pulse from ₁₀ ) and its Q output is "High".
Therefore, the output of the AND circuit (AN ₁₂ ) also becomes “High”, and thus the output of the OR circuit (OR ₁₀ ) is maintained at “High”. As a result, the motor drive circuit (MDR) is
Therefore, the taking lens is further extended beyond the in-focus position for infrared light. Then, pulses outputted from the number of encoder (EN) in accordance with the amount of the reverse rotation of the motor (MO) of this time is counted by a counter (CO _10), the output reading circuit of the counter (CO ₁₀₎
If the signal of ΔIR read by (DR) matches, the comparison circuit
The output of (DC) is inverted from “High” to “Low”, and the driving of the motor (MO) is stopped as in the above case. That is, this completes the focus adjustment to the focus position of the taking lens with respect to the visible light.

Thus, in the case of the embodiment shown in FIG. 12, drive control for focus adjustment of the taking lens is first performed based on focus detection by infrared light, and then the data output circuit (LDO) of the interchangeable lens. The photographic lens is driven for correction on the basis of the ΔIR signal from, and the focus of the photographic lens is adjusted to the in-focus position for visible light. This is the above-described other form of focus adjustment method of the present invention, but this is applicable even if the focus detection method is the so-called phase difference detection method described above. That is, in the phase difference detection method, the focus detection calculation circuit (13) outputs the above-mentioned signal Δl, but first the drive control of the photographing lens is performed based on this signal Δl, and the infrared light of the photographing lens is detected. After reaching the in-focus position, the correction drive of the taking lens may be performed based on the next signal of ΔIR. This will be explained more concretely by adding the above K information. Focus detection is performed on infrared light to drive the photographing lens, and the number of pulses from the encoder (EN) is N ₁ = K ·
When Δl is reached, the number of encoder (EN) pulses is N ₂ =
Drive the taking lens until it reaches K · ΔIR. That is, N = N ₁ -N ₂ = K (Δl−ΔIR), and as a result, this is equivalent to the focus adjusting method of the first embodiment of the present invention.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments. For example, when focus detection is performed only with infrared light, the beam splitter (7) shown in FIG. 1 is not necessary, and the light reflected by the sub-mirror (6) is passed through an infrared filter before focus detection. It suffices to relay on the photoelectric conversion means for use. In that case, it is necessary to consider the extension d / n of the optical path length of infrared light between the first and second reflecting surfaces (7a) and (7b) of the beam splitter (7). Therefore, the data output circuit (16) (LDO) may output the signal corresponding to the above-mentioned ΔIRo data.

Effect According to the present invention, the detection result when focus detection is performed based on visible light that is mainly used for shooting, and the detection result when focus detection is performed based on auxiliary light having a wavelength different from visible light The amount of deviation between and is stored in the shooting lens for each of the divided focal length areas, and the amount of deviation corresponding to that focal length is output to the camera body based on the focal length set by the shooting lens. Therefore, the focus can be detected with extremely high precision in the zoom lens.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an optical and electrical arrangement of a lens-interchangeable single-lens reflex camera of a first embodiment in which the focus adjusting method according to the first embodiment of the present invention is carried out, and FIG. FIG. 3 is a diagram showing the relative reflectance of the first reflecting surface of the beam splitter and the spectral sensitivity of the focus detecting photoelectric conversion means, FIG. 3 is a concrete circuit diagram of the focus adjusting device in the first embodiment, and FIG. Circuit diagrams showing the circuit configurations of the interface circuit and the data output circuit in the figure, FIGS. 5 and 6 are diagrams showing another circuit configuration of the data output circuit of the interchangeable lens, and FIG. 7 is a diagram showing the first embodiment. FIG. 8 is a flow chart showing the operation of the focus adjusting device, FIG. 8 is a circuit diagram of a main part of the focus adjusting device of the camera of the second embodiment of the present invention, and FIG. 9 is a schematic diagram of the focus adjusting device of the camera of the third embodiment of the present invention. Circuit diagram of the part, Figure 10 is the third FIG. 11 is a flowchart showing the main part of the operation of the focus adjusting apparatus in the embodiment, FIG. 11 is a modification of the flowchart of FIG. 10, and FIG. 12 is a fourth embodiment implementing the focus adjusting method of the second embodiment of the present invention. It is a circuit diagram of the focus adjustment device of. (IL) …… Interchangeable lens, (2) …… Shooting lens, (6) (7a) (7b)
(8b) …… Infrared focus detection optical system, (9a) (IRC) ……
Focus detection photoelectric conversion means for receiving infrared light, (13) (13 ′)
...... Focus detection calculation circuit, (14) (MDR) ...... Motor drive circuit, (MO) …… Lens drive motor, (16) (LDO) …… Data output circuit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location 7316-2K G03B 3/00 A (72) Inventor Norio Ishikawa 2-30 Azuchi-cho, Higashi-ku, Osaka-shi, Osaka Address Osaka Minami Building Co., Ltd. Minolta Camera Co., Ltd. (72) Inventor Akiyoshi Nakamura 2-30 Azuchi-cho, Higashi-ku, Osaka City, Osaka Prefecture Osaka Building Minolta Camera Co., Ltd. (72) Inventor Shuzo Matsushita Azuchi, Higashi-ku, Osaka City, Osaka Prefecture 2-30, Machi, Osaka International Building Minorta Camera Co., Ltd. Examiner Kazuhide Ozawa (56) References JP-A-57-154224 (JP, A) JP-A-58-88728 (JP, A) JP-A-59- 64816 (JP, A)

Claims (1)

[Claims] 1. A camera system having an interchangeable taking lens and a camera body, wherein the taking lens has a focal length setting means capable of arbitrarily setting a focal length within a predetermined range, and the taking distance is set by the focal length setting means. A focal length region detecting unit that detects which region of the focal length region the divided focal length belongs to is divided into a plurality of regions in advance, and the camera body detects the focus by the incident light incident through the photographing lens. And a fill light control unit that controls so that fill light having a wavelength different from the visible light mainly used for shooting is emitted toward the subject. The amount of deviation between the detection result of the focus detection means based on light and the detection result of the focus detection means based on auxiliary light is used for the focus detection. Storage means for storing each area, and an output means for designating a shift amount for a specific focus detection area according to the detection result of the focal length detection means and outputting the designated shift amount to the camera body, Further, the camera body is provided with a correction unit that corrects the detection result of the focus detection unit based on the shift amount input from the output unit when the focus detection unit uses the auxiliary light to detect the focus. A camera system characterized by being provided.