JPS59129839A - Focus detecting device of camera - Google Patents

Abstract

PURPOSE:To derect a focus in a wide range by photodetecting a visible light and an infrared-ray in a light of an object to be photographed by the first and the second photoelectric converting means, respectively, and detecting the focus adjusting state of a photographic lens basing on an output of the first or the second photoelectric converting element in accordance with whether its photoelectric converting output is large or small. CONSTITUTION:The outputs of a visible light photoelectric converting means 9a and an infrared-ray photoelectric converting means 9b are inputted to a discriminating circuit 11 and a selecting circuit 12, whether the outputs of both the photoelectric converting means 9a, 9b are large or small is discrimianted by the discriminating circuit 11, and a discriminating signal for indicating its result is outputted to the selecting output 12 and a gate circuit 13-1. A data outputting circuit 16 of an interchangeable lens side outputs a signal of a shifted amount DELTAIR of a focal position of a photographic lens 2 by a visible light and an infrared-ray, the gate circuit 13-1 controls passing of the signal of the shifted amount DELTAIR by a reading circuit 17, and when the output of the photoelectric converting means 9 is larger than the output of the photoelectric converting means 9a, the signal DELTAIR is made to pass through, and in case of the contrary, its passing through is inhibited, and a signal of the shifted amount DELTAIR=0 is outputted.

Description

Detailed Description of the Invention Technical Field This invention relates to a camera focus detection device that detects the focus of a photographic lens based on photoelectric conversion of subject light that has passed through the photographic lens, and in particular to focus detection in visible light and infrared light. The present invention relates to a focus detection device for a camera that is capable of detecting focus at both a camera and a camera.

BACKGROUND ART Various types of camera focus detection devices have been proposed in the past, which detect the focus of a photographic lens based on photoelectric conversion of subject light that has passed through the photographic lens, but most of them detect focus using visible light. However, when the visible light is weak, such as when the subject is dark, focus detection becomes difficult. Further, when a charge accumulation type photoelectric conversion element such as a COD is used as a photoelectric conversion means for focus detection, there is a drawback that as visible light becomes weaker, charging time becomes longer, and focus detection takes time.

However, photoelectric conversion means such as COD and photodiodes used for focus detection generally have better photoelectric conversion efficiency (sensitivity) for infrared light than for visible light.Also, even for black objects, infrared light It is also known that organic objects have a relatively good reflectivity for infrared light.Furthermore, if the subject is dark, it is also possible to perform focus detection by projecting an auxiliary light onto the subject. If visible light is used as the auxiliary light, it will have an adverse effect such as dazzling the subject when the subject is a person, so it is desirable to use light other than visible light such as infrared light as the auxiliary light. Therefore, there is no reason why focus detection during visible light photography must always be performed using visible light, and it is desirable to be able to perform focus detection using both visible light and non-visible light such as infrared light. .

JP-A-57-15080'8 proposes a camera focus detection device that is capable of both visible light focus detection and infrared light focus detection. This focus detection device is equipped with photoelectric conversion means for visible light and infrared light,
A beam splitter is installed in the focus detection optical system to split the subject light into light that is incident on the photoelectric conversion means for visible light and light that is incident on the photoelectric conversion means for infrared light. An infrared cut filter that blocks the passage of infrared light is provided between the splitter and the visible light photoelectric conversion means. Each photoelectric conversion means is connected to a selection circuit and a focus detection circuit via a discrimination circuit that discriminates the ratio of their outputs.

In other words, when photographing with visible light without using an infrared filter, this focus detection device makes a determination based on the assumption that the ratio of the outputs of the two photoelectric conversion means is constant regardless of the brightness of the subject. The circuit makes a determination, and the selection circuit outputs the output of the photoelectric conversion means for visible light to the focus detection circuit. On the other hand, in the case of infrared light photography using an infrared filter, the output of the photoelectric conversion means for visible light is smaller than the output of the photoelectric conversion means for infrared light, so the discrimination circuit is , and causes the selection circuit to output the output of the infrared photoelectric conversion means.

In this way, the focus detection device proposed in JP-A-57-150808 uses an infrared filter to determine the focus based on the output of the photoelectric conversion means for infrared light. When photographing visible light without using an infrared filter, focus detection is performed based on the output of the photoelectric conversion means for visible light. Since the ratio of the output of the photoelectric conversion means for light and the output of the photoelectric conversion means for visible light is not generally constant, the output of the photoelectric conversion means for visible light should always be selected when photographing with visible light. Setting a suitable switching level is difficult in practice. For this reason, even when shooting with visible light, focus detection is sometimes performed using infrared light, and because there is a difference in the focal position of the shooting lens for infrared light and visible light, only photos with poor focus are taken. I can't get it. That is, when the intensity of infrared light is greater than the intensity of visible light even under natural light illumination, or when the subject is illuminated with a light source that is stronger than infrared light or visible light, such as light source A (tungsten type), Even though visible light photography is performed, focus detection is performed using infrared light, and there is a risk that only a poorly focused photograph will be obtained.

Purpose This invention enables switching between focus detection using visible light and focus detection using infrared light in a simple manner, and even when focus detection is performed using infrared light, the photographing lens for visible light can be switched. It is an object of the present invention to provide a focus detection device for a camera that can accurately detect the focus adjustment state of a camera and perform focus detection over a wider range with high precision during visible light photography.

Summary 2 In the turtle focus detection device of this invention, the subject light that has passed through the photographic lens and is guided through the focus detection optical system is divided into first and second infrared light. The photoelectric conversion means each receive light separately, and the determination means determines the magnitude of the photoelectric conversion output. When the g discrimination means determines that the output of the first photoelectric conversion means that receives visible light is larger than the output of the second photoelectric conversion means that receives infrared light,
When it is determined that the output of the focus detection calculation means or the output conversion means of the first photoelectric conversion means is larger than the output of the first photoelectric conversion means that receives visible light, the focus detection means converts the output of the second photoelectric conversion means. The focus adjustment state of the photographic lens is determined based on the output of the photoelectric conversion means and the signal from the data output means indicating data on the amount of deviation of the focal position of the photographic lens in visible light and infrared light.
Detect state.

Embodiment First, the outline of the focus detection device of the present invention will be explained with reference to FIG. 1A).

In FIG. 1+Al, (2) is a photographing lens of a camera included in the interchangeable lens, (7) is a beam splitter constituting a focus detection optical system, and (9a) and (9b) are photoelectric conversion means. The beam splitter (7) is used to separate the subject light that has passed through the photographic lens (2) into visible light and infrared light, and has a relative reflectance (
A wavelength selective first reflecting surface (7a ) and a second reflective surface (7b) that reflects the light reflected by the first reflective surface (7a). This beam splitter (
In the case of 7), the first reflective surface (7a) transmits visible light,
Since infrared light is reflected, the photoelectric conversion means (9a) receives visible light, and the photoelectric conversion means (9b) receives infrared light. However, it is not essential in this invention to use such a Heems Brisoter in the focus detection optical system.
A beam splitter that simply splits the incident light in terms of quantity is used, an infrared cut filter is placed on one of the split optical paths, and the transmitted light is converted into visible light photoelectric conversion means (9a).
A visible light cut filter is arranged on the other optical path, and the transmitted light is converted into an infrared light photoelectric conversion means (91).
) may be configured to receive light.

Figure t (n) shows a specific example of a focus detection optical system for an eye reflex camera with interchangeable lenses using a beam splitter (7). 6) is a submirror held by this main mirror, (
8a) and (81)) are relay lenses, and the main mirror (1) and submirror (6) do not have wavelength selectivity and reflect light of different wavelengths. In addition, in FIG. 1 [B], (3
) is a pentaprism, (4) is an eyepiece, and (5) is a focusing plate. Further, the broken lines in FIG. 2+A][B+ indicate the relative spectral sensitivities (the highest sensitivity is taken as 1) of the photoelectric conversion means (9a) and (9b).

Of the object light that has passed through the photographic lens (2), the infrared light forms an image farther than the visible light, and the focal positions of the photographic lens (2) are shifted between the infrared light and the visible light. This shift is probably caused by the chromatic aberration of the photographic lens, and the amount of shift varies depending on various requirements such as the optical design and focal length of the lens, so in the case of an interchangeable lens, the amount of shift is unique to that interchangeable lens. Due to this discrepancy.

Generally, focus detection is performed using infrared light, and visible light photography is performed by setting the distance of the photographing lens to the in-focus position for the infrared light.
With interchangeable lens cameras, it is necessary to correct the focus detection result in infrared light by introducing the amount of shift inherent to the camera, but in visible light photography, the result is a poor focus. It is impossible to obtain a well-focused photograph based on focus detection using external light.

In the case of the configuration shown in Figure 81 fAl FBl, the optical distance from the taking lens (2) to the relay lens for infrared light (8b) or the photoelectric conversion means for infrared light (9b) is the same as that for visible light from the taking lens (2). The first and second reflecting surfaces (7a) (7) of the beam splitter (7) are longer than the optical distance to the relay lens (8a) or the visible light lunar photoelectric conversion means (9a).
The distance d in b) is divided by the refractive index n of the optical member constituting the beam splitter. (7)) If you do not change the lens, set 'l/n appropriately to convert visible light and infrared light into photoelectric conversion means (9a) (9).
(b) can be imaged at the same time. However, in the case of an interchangeable lens camera, d/n must be set to a standard predetermined value, and the above correction is required. In other words, If the amount of shift in focal position between infrared light and visible light specific to an interchangeable lens is ΔIRo, then Fig. 1 fAHBl
ζ In the configuration shown above, ΔIR data expressed as ΔI technique=Δ■艮o −d/n must be introduced into the camera.

In this case, is it sufficient to use infrared light of a desired wavelength as the basis for calculating ΔIR? If the aforementioned beam splitter (7) is used, the relative reflectance of reflection 1 (7a) and the photoelectric conversion means It is desirable to use infrared light having a wavelength of about 830 nm, which is the largest product of the relative spectral sensitivities in (9b).

Again, FIG. 1 (in Al, photoelectric conversion means for visible light (
9a), the output of the infrared photoelectric conversion means (9b) is input to the discrimination circuit (11) and the selection circuit (12).

Here, the discrimination circuit (11) discriminates the magnitude of the outputs of both photoelectric conversion means, and a discrimination signal indicating the result is sent to the screening circuit (12).
and a gate circuit (13-) in the focus detection calculation circuit (13).
Add 8 to 1). (16) is a data output circuit installed on the interchangeable lens side, and is a data output circuit for the visible light and infrared light shooting lens (2
) is output, and this signal is read by a reading circuit (17) and output. The gate circuit (13-1) is for controlling the passage of the ΔIR signal from the reading circuit (17), and the way the photoelectric conversion means (9b) comes out from the discrimination circuit (11) ) is output, the ΔIR signal is passed,
When the discrimination circuit (11) outputs a discrimination signal indicating that the output of the photoelectric conversion means (9a) is larger than the output of the photoelectric conversion means (9b), the passage of the ΔIR signal is prohibited; A signal indicating the amount of deviation ΔIR−〇 is output.

The selection circuit (12) selects the photoelectric conversion means when the discrimination circuit (11) outputs a discrimination signal indicating that the output of the photoelectric conversion means (9a) is larger than the output of the photoelectric conversion means (9b). (9a), and when the discrimination circuit (11) outputs a discrimination signal indicating that the output of the photoelectric conversion means (9b) is larger than the output of the photoelectric conversion means (9a), the photoelectric conversion is performed. The outputs of the means (9b) are each sorted and outputted to an arithmetic circuit (13-2) in a focus detection arithmetic circuit (13).The arithmetic circuit (13-2) also receives the output from the selection circuit (12). outputs a signal Δl indicating the amount of focus shift and its direction, and this signal Δl is sent to the gate circuit (13
-1) is sent to the addition/subtraction circuit (13-3). Then, the addition/subtraction circuit (13-3) outputs the signal from the gate circuit (13-1) or the signal IΔ11 in the case of cello, and the signal 1++ or (-) indicating the direction of the focus shift. - Signal from the circuit (13-1) or ΔI
1Δ when R! -ΔI Rl signal and a signal (+) or (-) indicating the direction of the focus line are output, and the display device (
DP) performs display based on these signals.

In this way, in order to detect both the amount of focus shift and its direction, the arithmetic circuit (13-2)
What is necessary is to perform the calculation shown in the No. 510 publication. Here, the display on the display device (Dr) is a photoelectric conversion means for visible light (
When the output of 9a) is selected and focus detection using visible light is performed, it is performed based on a signal of 1Δdl, and the output of the infrared photoelectric conversion means (9b) is selected and focus detection using infrared light is performed. When focus detection is performed, it is performed based on a signal of 1 in 1Δl-Δ■, so in any case, visible light (visible light) accurately indicates the focus adjustment state of the photographing lens.

Next, an embodiment in which the focus detection device of the present invention is implemented using a microcomputer in an interchangeable lens type eye reflex camera will be explained. The lens is configured so that focus adjustment of the photographic lens can be performed automatically based on the number of turns.

3 to 7 show that a monitoring photoelectric conversion element is provided to select whether to use the output of the photoelectric conversion means for visible light or the output of the photoelectric conversion means for infrared light for focus detection. 1 shows a first embodiment.

(IR, D) HA'iS 1 [IAl) Photoelectric conversion means (9b) I installed photoelectric conversion elements for monitoring infrared light, (VSI) ) is the photoelectric conversion means (9a) in the first section. ) is a photoelectric conversion element for monitoring visible light.

These photoelectric conversion elements are operational amplifiers (OAl), (
OA2) and logarithmic compression diode (Dz, ) (D2
) constitutes a photometry circuit for monitors. Operational amplifier (OAl).

The outputs of (L)A2) are compared by a comparator (Ac1), and if the monitor output of infrared light is thicker than the monitor output of visible light, the output of the comparator (ACI) is
'i] i gb ” i If the visible light monitor output is larger than the infrared light monitor output, the comparator (AC
The output of I) becomes “Low” (see the blank below). In addition, the output of the operational term 1 notification device (OAI) is compared with the output of the constant voltage source (CF2) by the comparator (AC3), and the monitor output of infrared light is compared with the output of the constant voltage source (CF2).
If the output of the comparator (AC3) is smaller than the output of the operational amplifier (OA
The output of 2) is compared with the output of the constant voltage source (CE◇) by the comparator (AC2), and if the monitor output for visible light is smaller than the output of the constant voltage source (CEI), the output of the comparator (AC2) is “ H; Becomes gh I+.

Inverter (IN,), AND circuit (Ha), (Ha2)
, OR circuit (ORI), (OR2) is the above-mentioned no comparator (Act.

Based on the outputs of (AC2) and (AC3), infrared light photoelectric conversion means (9b) and visible light photoelectric conversion means (9a)
) to use, and the auxiliary infrared LED (
IRL) outputs one word indicating whether to emit light. Table 1 shows comparators CAC, ), (AC2), (
The relationship between the output of AC3) and the output of this cooking circuit is shown r0 (φ may be L or H). Instead, a light receiving section for infrared light is used, and if the monitor output of infrared light is below a certain value, the infrared illumination light source is turned on. on the other hand,
If the monitor output of infrared light is smaller than the monitor output of oJ inkstone light, if the monitor output of visible light is above a certain value, the light receiver for visible light is turned on, and the light source for illumination is not turned on. If the visible light monitor output is smaller than a certain value, the infrared fish light source is turned on and the infrared light receiver is used.

The output of the OR circuit (OR, ) is a D flip-flop (D
Fl) (7; To D input, OR circuit (DF2) output; From 7 flip-flops (DF, connected to D inputs of j respectively, D flip-flops (DFl),
Since a light metering operation start signal for focus detection from a microcomputer (MCO) to be described later is input to the clock terminal of (DF2), an OR circuit (ORI), ( Discrimination signal from OR2) or D flip frog (DF+),
(DF2) +This is latched (CO'r) is a controller that controls the timing of photometry operation for focus detection, (■Rc) is provided in the infrared photoelectric conversion means (9b) A CCD for focus detection, (VSC) is a CCD for focus detection provided with photoelectric conversion means (9a)f for visible light.
It's a CD. (SH) is CCU (IRC) or (vs
(AI)) is a circuit that samples and holds the analog signal from C), and (AI)) is a circuit that performs AD conversion on the output of the sample and hold circuit (SH).

Microcomputer (84CO) output terminal (0;
+) sends a pulse to the terminal (s”r) of the controller (COT) to instruct the start of the photometry operation for focus detection, and the controller (CO'r) sends the analog switch I'AS, ;) (Ash ) is outputted from the terminal (φ1 shoe), and due to the conduction of this analog switch (AS,) (ASa), the CCD (J
RC) (VSC) is charged through the terminal IAD) (VAD) up to the output potential of the constant voltage source (CE, ).

It will be done. The reset pulse from this terminal (φR) is also input to the set terminal of the flip-flop (FFI), and the pulse from this terminal (φR) causes the flip-flop
If the flop (FFI) is set and the Q output of the D flip-flop (DFl) is lj Hlgh ++, the output of the AND circuit (AN3J becomes "high ++" and the transistor (BTi) becomes conductive, and the lighting The infrared light emitting diode (IRL) of the CCD (JRC
), (VSC) accumulates the charges output by those light receiving parts (individual charge conversion elements), and terminals CIAD),
(VAL)) outputs a potential corresponding to the accumulated charge. At this time, if the Q output of the D flip-flop (DF2) is 'High' (infrared CCD (IRC
), the analog switch (AS4) becomes conductive and the potential from the output terminal (IAD) of the CCI) (IRC) is input to the comparator (AC4). -force,
The output of the D flip-flop (DF2) is 'f(ig
If h"' (when using CCI for visible light) (VSC) 1, the analog switch (ASI) conducts,
The potential from the output terminal (VAf) of the CCD (VsC) is input to the comparator (ACa).

Comparator (AC4) is connected to terminal (IAD) or (vAD)
) and a constant voltage source (CE3
) and if they match, IIHl
Sends the gh IT signal to the controller (CO'l).

Then, the controller (C (JT)) outputs a transfer pulse from the terminal (φT), and CC1) (IRC), (VSC)
Transfers the accumulated charge to the transfer gate. This transfer pulse is also sent to the sector terminal of the flip-flop (FFI), and the flip-flop (FF, ) is sent to turn off the light emitting diode for illumination (H<L,). From then on, the transfer clock (φ
1), (φ2), and (φ3) are sequentially output, but at this time, the D flip-flop (
If the Q output of DF2) is "High", the analog switch (Ash) conducts and inputs the infrared light reception output from the terminal (IKS) to the sample/hold circuit (SR) #C, while the D flip・If the flop (DF2) output is “l Hr gh ++”, the analog switch (AS2) becomes conductive and inputs the visible light reception output from the terminal (VSS) to the sample/hold circuit 4 (SH). I.

:] The terminal o-'5 (COT) outputs a sample-and-hold period pulse from the terminal (φS), and then outputs a pulse from the A-D
A pulse for starting conversion is output from the terminal (φC). Then, the A-D converter (AD) is connected to the sample hold circuit (SH
) converts the output from A to D (this controller (CO
T) is connected from the terminal (TR) to the microcomputer (''■
The microcomputer (MCO) outputs 3 pulses to the input terminal (14) of the microcomputer (MCO) to indicate data transfer.
) outputs the 8-0 converted data by the AD converter (AD) to the input port (IPI) of the converter (AD). After this, the above-mentioned operations of outputting the accumulated charge, sample and hold, A-D conversion, and data transfer are repeated, and the ccD (JRC)
When the transfer of data equal to the number of light receiving sections of (VSC) is completed, the controller (COT) transfers data from the terminal (EN) to the input terminal (16) of the microcomputer (MCO).
In this embodiment, a photoelectric conversion element (IRD) for a monitor and a monitor is used to send a data transfer completion pulse to initiate the operation.
.

(VSD), but even if such a monitor photoelectric conversion element is not provided, either CCD
It is possible to switch whether or not to use the output of the light emitting diode and to determine whether or not to light the light emitting diode for illumination. That is, before the photometry operation for focus detection, the CCD (IRC
), (VSC), and the outputs of the terminals (IAD) and (VAD) based on this accumulated charge ζ are made the same as the discrimination circuit shown in Figure 3. Before starting the photometry operation for focusing (this D flip-flop (
i) F+), (DFj + This latch is good.

Next, the remaining circuit portions in FIG. 3 will be explained. (E) is a battery for power supply, (MS) is a switch that is closed when the release button (not shown) is pressed in the first step, and this switch (M
When S) is closed, the output of the inverter (IN2) becomes II
Became Hr gh II and microcomputer
.

(MCO) starts focus detection and focus adjustment operations, while the light metering/arithmetic/display circuit (LM) for exposure also starts its operation. In addition, micro computers (tVlc)
Jl becomes the terminal (01) when the switch (MS) is closed.
) is set to "High", the output of the inverter (IN3) is set to "Low", and the transistor (B
r3) is made conductive to supply power from the power supply line (Vcc). The switch (RS) is a switch that closes when the release button is pressed @2 steps, and when this switch is closed, the output of the inverter (■N4) becomes "High"'
1. At this time, if the exposure side cooling circuit (EC) is in the preparation state and the output of the inverter (iNo* is "High", the output of the AND circuit (ANo) becomes "High", and the microcomputer [ ]Q starts focus detection and focus #I u'!th operation and waits for exposure control operation to stop.Exposure control circuit (EC month, switch (R
5) is closed, the exposure control operation is performed based on the exposure control value from the photometry/arithmetic/display circuit (LM), and when the exposure control circuit is completed, the microcomputer (Mco
) (7) Send an operation completion signal to the input terminal (it) "'High". This signal goes "'L" when the exposure cooking mechanism is fully charged and ready for exposure control operation.
It becomes “ow”.

The display unit (DP) is a microcomputer CMC0)
(Displays front focus, rear focus, and focus based on data from the D output port (OPl). Motor drive circuit (
MDR) rotates the motor (MO') forward or reverse based on data from the output port (OF2), and moves the lens to the in-focus position via the lens driver m (LDR). Further, (EN') is an encoder for monitoring the amount of rotation of the lens drive mechanism (, 1-pR), and outputs one pulse every time the lens drive mechanism (LDR) rotates by a predetermined amount. (IF) is a microcomputer (MCO)
) The data output circuit (LDO) of the interchangeable lens is rotated by the pulse from the terminal (02) of the lens.
Data ΔIR indicating the amount of deviation between the infrared focus position and the visible light focus position and the lens rotation amount for a predetermined rotation amount (predetermined number of pulses from the encoder (EN)) of the lens drive mechanism (LDR). and is sent to the data on the ratio of the amount of movement.

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

In Fig. 4, when a pulse of l Hr gh 11 is input from the terminal (02) of the microcomputer (Mω), the flip-flop (F) is set and the next clock pulse from the oscillator (OSC) is input. At the rising edge, the Q output of the D flip-flop (pFs) goes “High.”
h”.This results in an AND circuit (AN to)
is opened, the clock pulse from the oscillator (OSC) is input to the ring counter (COt), and the ring counter (COt) sequentially outputs terminals (ba) and (bt) from the rising edge of the clock pulse to the next rising edge.・・・・・・
(bO).

(bo), (bt) ・・-(b,) II Hlg
h I will make it II. On the other hand, D flip-flop (D
The Q output of E5) is the sixth factor, the lens side data output circuit (L
DO) is also transmitted through the terminals (Jt) and (Jl).When this Q output rises to "l High 11", the latch circuit (LA3) is connected to the analog switch (AS+5) from the shooting distance output section (DD). The data of the shooting distance of 5 points and 1 point inputted through (AS19) is latched.Then, after a time determined by the delay time of the delay circuit (DL), the output of the delay circuit (DL) becomes "High". ', the output of the inverter (IN+o) becomes "Low", the analog switches (SAID) to (AS14) become conductive, and the 5-bit focal distance data from the focal length data output section (FD) is output. The focal length data output section (FD) and photographing distance data output section (DD) that are input to the latch circuit (LA3) are both composed of code boards, and these total 10 bits of data are generated using the above structure. If,
It is possible to input data to the IC circuit (circuit portion surrounded by a dashed line in FIG. 4) using six terminals. In addition, in the example of FIG. 4, the above-mentioned data ΔI
An example of an interchangeable lens in which R and K change is shown, and therefore the above-mentioned two data are required.

The photographing distance data from the latch circuit (LA3) and the focal length data from the analog switches (ASlo) to (AS14) are input to the decoder (DE3) and converted into 6-bit data. And this data is in ROM
It is input to the address terminal of the lower 6 bits of (RO).

In addition, the Q output of the D flip-flop (DFs) causes the terminal (J,') to become High, so that the terminal 02
A clock pulse from an oscillator (OSC) inputted via the oscillator (OSC) is inputted to a ring counter (CO□) having the same configuration as the ring counter (cod) in FIG. 5 through an AND circuit (AN14).

When the terminal (bl) of the ring counter (CO□ in Fig. 4) becomes "High", a "High" signal is input to the counter (CO3) via the terminals (J3) and (J3'), and the counter (The outputs Q1' and Qo of CO and J are "01"
becomes. The output of this counter is ROM (RO)
is input to the address terminal of the upper 2 bits of RO
M (, RO) is °'0IXXXXXX” (×...
The address of the decoder (DE output) is specified, and ΔIR data corresponding to the focal length and photographing distance is output. Then, the ring counter (CO2) terminal (
When L2) rises, this ΔIR data is taken in parallel to the shift register (SR2). From then on, ΔIR data is sequentially output from the output terminal (OUT) in synchronization with the rising edge of the clock pulse, and the ΔIR data is sequentially output from the output terminal (OUT). ．．勺、(
J4) to the camera side interface circuit (IF)
The data is taken into the shift register (SR'+) at This shift register (SRI) stores data at the falling edge of the clock and becomes 0, so 8-bit data is transferred from the terminal (b2) or from the falling edge of the clock pulse when it is "High" to the terminal (b0). ) is “'High
The shift register (SRI) tL is taken in until the falling edge of the clock pulse 1° when the clock pulse is 1°.

When the terminal (bl) rises to High for the second time, the Q output of the D flip-flop (DE7) goes high.
At this time, the D flip-flop (D
Since the 4 outputs of E8) are "High'", the AND circuit (A
Nn) outputs a high /sO pulse from the terminal (bO), and at this rising edge, the U-nch circuit (L
data ΔIR from the shift register (SRI) to
is latched. And next, the ring counter (Cot
) becomes “l High II” for the second time, the counter (CO3) becomes the terminal (J3), U
3') receives this "l High II signal, and its output Q1. Qo becomes "l 1. OII, and R(I
V(RO) is designated with the address "10XXXXXX" and outputs K data corresponding to the focal length and shooting distance. This data is taken into the shift register (SR2) at the rising edge of the terminal (R2) of the ring counter (CO2), and thereafter, in synchronization with the rising edge of the clock pulse, each bit is sequentially transferred to the terminals (J4'), (J4). is input to the soft register (SRI) in the camera side interface circuit (IF) in Fig. 5 via ” from the rising edge of the clock pulse F to the terminal (b,) is 11 Hr gh
8-bit data K is taken into the shift register (SRI) until the falling edge of the clock pulse at time II.

Next Nilling Counter (COI) (7) Terminal (bo
) rises to llh1ghl+ and the D flip-flop (DF8).

The output becomes L Hlgh T+, and the AND circuit (AN1
From the output of 2), “l High” from the terminal (bo)
11 pulses are output and shift register (SR1)
The data K stored in is latched by the latch circuit (LA2). In addition, the output of the AND circuit (AN, □) is passed through the OR circuit (OR1o) to the -c1 flip-flop (
FF5), D flip-flop (DFr,), (DF
+;'), (1) R7), L, t) F, ノ, link counter (CO+) is sent to the positive terminal, and the rising edge of the output of the negative circuit (AN1□) is One circuit is set. Also, from this reset I) The Q output of the Sirinobu flop (DF, ) is 1, IIW ”
The signal that goes to 1 is the terminal (J1'), CJ
+′) and the counter (
CO2), CCO:+) Noricent g = sent to the child, and their output ('-0, ”E, i
CO3, ) is also rehinted.

Repeat the above operation for 1 degree.
Depending on the state of
'21, ("I I] 1) microcomputer tMC (month; this 1,, furthermore, (, PO
,) and (1'0.,) are power-on reset circuits, and when the transistor (fT,) in Fig. 3 becomes conductive, and power supply starts from Vcc), It'lt
It outputs a reset signal,
) n l are the first circuits (, moe < lu , 'l ,
l, t) Output via Igj1no, Frinois flop lFF, I, D flip 70 knob (1) F
5 ADFs, (Wγ), CDF8), counter (C
o1), (CO2), and '(CO3) are turned off and reset.

FIG. 5 shows an embodiment of a data output circuit (LDO) for an interchangeable lens in which AiR and K change depending on either the focal length or the photographing distance. Components or circuit elements similar to those in FIG. 4 are given the same reference numerals.

In the case of this interchangeable lens, the top 2 of -ROMCRO)
The bits are addressed by the output of the counter (CO3), the least significant bit is connected to ground, and the remaining 5 bits are addressed by data from the focal length data output (FD) or shooting distance data output (Dt). be done.

The remaining circuits are the same as those shown in FIG.

FIG. 6 shows an embodiment of a data output circuit (LDO) for an interchangeable lens in which AiR and K are fixed. In this embodiment.

By using a diode array (DIA) instead of ROM, the terminal (Q, ) of the counter (CO3) is *High.
'1, the AiR data of the diode array (DIA) connected to this terminal (CQo) is output,
When the terminal (Ql) becomes II Hr gh II, this
Diode array (DI) connected to terminal (Q)
A) K data is output.

Other parts are the same as in FIG. 4.

Next, Fig. 7 shows a microcomputer (MCO).
) The operation of the concave path shown in FIG. 3 will be explained based on the flowchart of FIG. When the switch (MS) is open, the microcomputer (MCO) is in the state of "HAL'r", which is inactive with low consumption and mental energy. Switch GvlS
) is closed, the inverter (IN2) is closed.
gh” output is input to the interlaced terminal (it),
The microcomputer (MCo) starts operation from step #0. In step #O, the terminal (ol) is set to High and the output of the inverter (IN3) is
Low" to make the transistor (B'r 2 ) conductive. Therefore, power supply by the power supply line (Vcc) is started.

Then, in step #1, the switch (R5) is closed and the output of the inverter (IN4) becomes "'High", and it is determined whether the input terminal (13) is "°'High" or not. The input terminal (i3) is °“f(ig
h”, the exposure control operation will be performed, so #41 will be described later.
Move to the next step. If the terminal (i3) is "Low", a "High" pulse is output to the output terminal (03) to start the above-mentioned photometry operation for detecting scorched fish, and further, in step #3, the terminal (0□) outputs a “High” pulse to output data ΔIR from the above-mentioned interchangeable lens,
Start the K reading operation.

Next, in step #4, the input terminal (14) is set to “High”.
”, then (i4) becomes “l H]gh I+
Then, from the input port (IP+) to the controller (C
It is determined whether the terminal (16) is l H1gh I+ (the value obtained by A-D conversion of the accumulated charge by the combined light receiving section of CCD (VSC) or (IRC) ≠). If it is L-Low++, the process returns to step #4 and takes in the next data. On the other hand, in step #6, the input terminal (I6) is set to l H1gh
When it is determined that it is I+, CILL) (v] C)
Or A- of the accumulated charge due to all the light receiving parts of (IRC)
This means that the import of the D-converted value is completed, and the process moves to step #7. At step #7, switch (R8)
is closed, and it is determined again whether the input terminal (i3) is output ghl+. t'And (i3) is "' High
h”, the process moves to step #41.

In step #7, input terminal (i3) is 11 FI 1g
If it is not h I+, the process moves to step #8, and the 7-ta of ΔR is stored from the input port (IP2), and then the data of K is stored from the input port (IP3). And #1
In step 0, the focus shift amount and direction are calculated based on the data taken in from the input port (IP, ). This calculation may be performed, for example, as shown in Japanese Patent Laid-Open No. 67-45510. Then, in step #11, it is determined whether the input terminal (15) is "I H1gh I+", and if it is "High", the infrared CCU (
IRC) using the output of Δl! (Focus shift amount and direction) has been calculated, so data ΔIR of the focus position shift amount for infrared light and visible light and data K of the ratio of the rotation amount of the lens drive mechanism and the lens movement amount. Based on K.
∆l - ∆IR)2N calculations are performed, and the encoder (EN
) to calculate the number of pulses N to be input. on the other hand,
Step c terminal (i,) of #ll is °'High''
If it is determined that it is not ``, the CCD for uJ i light
(VSC), the data of "■1<" is not used, and the number N of pulses to be input from the encoder (EN) is calculated by performing the calculation of K, .DELTA.l=H and f.

In step #14, the focus matching state is displayed, the input terminal (13) is determined in the same way as described above, and
In step 16, it is determined whether the number N of pulses is 0 or not.

Then, if N is O, the process moves to step #38, which will be described later, while if N\0, the process moves to step #17, where N is set in the register M in the microcomputer (MCO+).Then, the motor (lν10 ) starts forward or reverse rotation depending on the direction of focus shift, and sets data P in register P in the microcomputer (MCO). Then, pulses are input from the encoder (EN) and input It is determined whether the terminal (1ρ) has become "High", and if it is "Low", the process moves to step #27, and if it is "l n 1g h I+", the process moves to step #21.

In step #27, it is determined whether the switch (R5) is closed and the input terminal (13) is "High", and if it is 11 H; gh I+, the exposure control operation is started. After stopping the rotation of the motor (MO) and resetting the flag JF in the microcomputer, which will be described later, the process moves to step #41.On the other hand, if the input terminal (j,) is "Low" In step #28, subtract 1 from the contents of register P and determine whether d in P is 0. Then, if (P)\0, step #3o determine whether C flag JF is 0 or not. If so, return to #20 and determine whether the input terminal (12) or "l H1gh I+" is present. If it is "Low", the process returns to step #27. Therefore, the input terminal (!2
) repeats the above operation until (P
) == If the terminal (12) does not become "High" within a certain period of time until it becomes 0, even if the motor (MO) is driven, for some reason (for example, the lens has been moved to the closest position) And lens FA motion m? 14 hf Since it is not possible to move more than that, stop the rotation of the motor (MO) in step #33, display a warning, reset flag JF, and move on to step #38. .

When it is determined in step #20 that the input terminal (12) is 'High', 1 is subtracted from gN in register M in step 7 of $21, and the contents of M become O. (M) If the ball is 0, set flag JF to 1 and register P to P.

Set the data to make the input terminal (1°) “Low”
7, and “l n
If i gh +1 remains, the flow moves to step #27 described above to count a certain period of time, and in this case, the flag JF is 1, so step number #25 (.

return. The name of this place is also (P) 20l, since the lens has been driven to the closest position, #33 moves to the first flow, stops the motor, and displays the % notice. Then - reset the C' flag y and #38
Then, when it is determined in step #25 that the input terminal (12) has become "Low", the flag JF is reset and the process returns to step #19.

In addition, here the input terminal (12) is "l H1gh 11
1 is subtracted from the contents of register M, but the input terminal (12) is "f Low".
When it becomes u, subtract 1 from the contents of register M to determine whether the contents of M have become O, and (M) =
If it is O, move to step #36, and for N, calculate twice the value of this example. Count the rise and fall of the pulses of the lf1 encoder (EN) ρ), etc. This improves the accuracy of lens focus adjustment.

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

In step #38, it is determined whether the switch (MS) is closed and the input terminal (17) is "High".

If the input terminal (17) is “High”, #1
Return to step and repeat the same operation as above to obtain (i,
) is Low, turn off the display in step #39, set the terminal (0□) to IL, OW II, stop the power supply from the power line (Vcc) by the transistor ■, and turn off the microcomputer. (MCO) is “HALT
If it is determined that the switch (R8) is closed, wait for the input terminal (i,) to become "High" in step #41. After the exposure control operation is completed, the exposure control circuit (E
When a "High" pulse is input from C) to the input terminal (11), the process moves to step #38.

Next, a modification of the above first embodiment--stumbling blocks to be explained in detail.
The photoelectric conversion means for focus detection is not an integral type like a CCD, but may be one that outputs a signal corresponding to the instantaneous light intensity like a photodiode array. Also, the calculation of Δl is as follows: Although we have shown an example in which digital calculations are performed based on digital values obtained by A-D converting the photoelectric conversion output, analog calculations are performed based on analog outputs, the calculation results are A-D converted, and this digital value is converted based on this. The motor may be controlled and displayed.

Below is Kokihaku Figure 8 shows a photoelectric conversion means (I) for monitoring.

A second embodiment of the present invention is shown in which the control is performed and it is determined which of the outputs of the CODs to be used.

The counter (colo) is reset by the reset pulse (9h), and counts the time based on the ri/k pulse (ri 1), e.g. When the Q pulse is output, the terminal (IAD) output and (VAD
) and the output of the constant voltage trace (CE) are determined by the comparators (AC2o) (ACll), (, AC12), the AND circuit (AN21), (AN22.), and the inverter (lN2o). are D flip-flops (DF20), (DF21)
le,.

Cocote, LAD (VAD TeIAD<CEIO Mataha IA
I): 4VAD teVAD (CEzo (7) case 1c
Huff' 7 Toipl Road (AN21), (,,8N
22) are both “Lovy” and the Q outputs of the D flip-flop (L) k2o) + (DF21) are both “°’ +y%V”, and the OR circuit ((J
Rzl) output is II Low, remains 1 and becomes 7I], and the external spectroscopic diode (11 (L) does not emit light. In this case, at the time of 4QmSeC, LL; D (LRG) or (■
``SC) (7) Since the output has reached the output of (CE 1 o), it will change from C to l) within a certain period of time (for example, 8・+m5ec) without emitting light from the infrared light emitting diode (IRL). charging will be completed.

On the other hand, IAI) (IAI in VAD)\CEI.

Again, IAv’, VAD with 〇”,, CEz.

In the case of , AND circuit (AN21) or (AN22)
The output becomes °'fii gh'' and the counter (
At the moment the pulse is output from CUlo), the output of D flip-flop (DF20) or (DF21) becomes °'
)iiih", and the output of the OR circuit (Ok21) becomes "
)iii"1. This causes the light emitting diode (IKL) to stipple and provide infrared illumination. The reason for this infrared illumination is that if the CCD continues to accumulate during illumination. This is because the accumulation time takes a certain period of time (80 mSe or more), so the measurement does not take long.

The output of terminal (IAI)) or (VAD) is a constant voltage source (
When the level of C1itt) is reached, the comparator (AC1
3) The output of (AC14) is inverted to 'High' and the one-shot circuit (O5to) or (O511)
The pulse of “degh” is emitted from the blade. At the time this pulse is output, the flip-flop (FF1o), (i
``F11) are both in the reset state, and the gates of the AND circuits (AN23) and (AN24) are both open, so the above pulse is generated by the AND circuit (AN2).
3) or (24 to A) to flip-flop (P
It is applied to the set terminal of IF'1o) or (FFII), and one of the flip-flops becomes set. When the flip-flop (FF1o) is in the set state, the gate of the AND circuit Ml (AN24) is closed, and when the flip-flop (1-'Fil) is in the set state, the gate of the AND circuit (AN23) is closed. Since it is closed, this state will be maintained until a reset pulse is input from the terminal (03).When one of the flip-flops (1-'Fto) and (FF'tz) is in the cent state, the OR circuit is activated. (Is it the output of (JR23) °' tr
i gh”, and this signal is sent to the controller, (CL
) 'I') Transfer pulse (96T)
is output.

Also, the quick output of the flip-flop (i''h' 10 ) is the analog switch ('''') + (l'''F 1
Since the Q output of t ) is connected to the control terminal of the analog switch (As 2 ), the signal of which the accumulation of tag It is adopted as a signal. Konchi, CC1-
, I whichever reaches a predetermined value first is used as a signal for focus detection.

The output of OR times m ((JR23) is a one-shot circuit (0
512) is also manually operated, and when the output of the OR circuit (UR23) reaches 11igb, the one-shot circuit (0
512) The "1-ji gh" pulse is output, resets the D flip-flop CD)'20)l (DF21) through the OR circuit (Ok24), and the light emitting diode (ikL) lights up. It disappears.

The counter (01t) is reset by a reset pulse (96Rl), counts the clock pulse (961,), and outputs a pulse after a certain period of time (for example, ?□m5eQ).This counter (C011)
When a pulse is output from the comparator (A(13)
) l (AC14) outputs are both °I LOWll
If so, OR circuit C (JR22), AND circuit (AN
23), the pulse from the counter (C(hl)) is input to the set terminal of the flip-flop (FF10), and the flip-flop (FF1o) enters the cassette state.This causes the transfer pulse (φT) to be output. Then, the output of the infrared CCD (IRC) is adopted as the signal for focus detection.In this case, the accumulated charge will not reach the predetermined value within 3Qmsec, but focus detection is possible, so the time Integration is forcibly stopped at 8QmSeC for shortening.Furthermore, in this case, since the light emitting diode (I RL ) is emitting light, the output of the infrared CCD (IRC) is cco for visible light (vs
There is a high probability that the output is higher than the output of c), so CC for infrared light
It is configured to adopt the output of D.

Finally, a focus adjustment device for an interchangeable lens camera that determines the magnitude of the output of the photoelectric conversion means for visible light and the output of the photoelectric conversion means for infrared light, and adjusts the focus of the photographic lens based on the larger output. Another circuit example is shown in FIG. 9. In this circuit example, when detecting the focus using infrared light, the signal number indicating the focus adjustment state of the photographic lens for the infrared light is the aforementioned ΔI 11.
- The correction is not performed based on the signal ΔIR, but after driving the photographing lens to the in-focus position for infrared light based on the signal indicating its focus adjustment state for infrared light, It performs correction drive according to the
In this sense, this embodiment is different from the embodiment of the present invention. In addition, in the case of this circuit example, the focus detection method is, for example, disclosed in Japanese Patent Application Laid-Open No. 57-8841.
No. 8, JP-A-57-72, . This method is disclosed in Japanese Patent No. 110, and only a signal indicating the direction of focus shift is output as a signal indicating the focus adjustment state of the photographing lens.

That is, in FIG. 9, the focus detection calculation circuit (13'
) is based on the output from the selection circuit (12) of fA+ in Fig. 1. In the so-called front pin state, "
In the so-called rear focus state, a "High" signal is sent to the terminal (C1), and in the focused state, the "High" signal is sent to the terminal (bl).
Outputs the 'i (high) signal to the
The display device (DP) in the viewfinder of the camera displays each status according to the signal h''''. Also, the terminal faltc] of the circuit (13') is connected to the AND circuit (+6J'J4
o) (AN41) (7) It is connected to one input, and the terminal tbl is connected to the same ant circuit (/'1lN40) (
AN41) is connected to the inverting input of the AN41).

The motor drive circuit (MDR) is an AND circuit (8 to 40
) output l is connected to the stop (or circuit (OR40)
The output number of the AND circuit (AIN41) is connected through the
For example, when the output of the OR circuit (OR40) is 'High'', the motor (MO) is rotated in the reverse direction to advance the photographic lens. Let's do it.

Further, when the outputs of the 7 ant circuit (AN40) and the OR circuit (OR40) are no longer "peak gh", the drive of the motor (MO) by the motor drive circuit (MI)R) is stopped.

The terminal (+) of the circuit (13') is an AND circuit (c42)
is also connected to one input of the AND circuit (A
In this case, the discrimination circuit (11) on the other side of the Photoelectric conversion means (9
When the output of the photoelectric conversion means for visible charging (9a) is larger than the output of the photoelectric conversion means for infrared light (9b), it outputs a 'Low' signal.
” signal is output.

The one-shot circuit (O5a o) is a discriminator circuit (11
) When the output of the circuit (13') is "High" and a "High" signal is output to the terminal (bl) of the circuit (13'), a pulse is generated to set the flip-flop (FF40), and as a result, A flip-flop (FF40) connected to one input 5' of the AND circuit (AN43)
)'s Q output becomes "High". Also, the pulse from the one-shot circuit (0540) is sent to the encoder (E
Counter (CO4) that counts the balloons from CO4
0) is reset. The digital comparison circuit (DC) is
The output of this counter is compared with the data output ΔIR of the interchangeable lens data output circuit (LDO) output from the data reading circuit (DJ), and when they match, the other one of the AND circuit (AN 43) is The output connected to the input is inverted from "'High" to "Low".

The output of this AND circuit (AN4a) is connected to the other input of an OR circuit (OR40), one input of which is connected to the input of the AND circuit (AN41).

Also, when the output of the comparator circuit ('D C) changes from "High" to °'Low, the one-shot circuit (O541)
or reset the flip-flop (FF40).

According to this circuit example, focus detection using infrared light has started, and now the terminal fat of the circuit (13') is high.
If the signal “°” is output, the AND circuit (A, N
The output of <O) becomes “High” and the motor (MO
) or the camera lens is reloaded. As a result, when the focal position of the infrared light of the photographing lens coincides with the film plane, which is the intended image formation plane, the output of the terminal fat is "
The output of the terminal (bl becomes gh').

Then, the one-shot circuit (0540) or this terminal tb
It receives the output of l and outputs one pulse, and the flip-flop (FF40) is set and outputs Q or "I-1i g".
h”, the output of the AND circuit (AN43) and the OR circuit (OR40) also becomes °゛ggh', and the motor drive circuit (MD 艮) reverses the motor (MO) and turns the photographing lens into an infrared light. It will be drawn out from the position where it is focused on the light. At this time, the counter (
CO40) and the counter (CLJ4
0) is read by the reading circuit (L)R)
It is compared with the IR signal by a comparison circuit (DC). Then, when the output of the counter (CO10) matches this ΔIR signal, the output of the comparison circuit (DC) becomes “'High”.
In order to invert from “Low” to “Low”, an AND circuit (AN
43), the outputs of the OR circuit (OR40) are both Low'“
At this time, the output of the AND circuit (AN40) is also 11
Since the motor drive circuit (MDR
) The drive of the motor (IVIO) stops. That is, as a result, the photographing lens reaches the in-focus position for visible light and stops, and the focus adjustment of the photographing lens to the in-focus position for visible light by focus detection using infrared light is completed. In addition, °'H of the 8 forces of the comparison circuit (DC)
The flip-flow knob (FF40) is reset by the pulse output from the one-shot throat circuit (O841) due to the inversion of "Low" from ig11'", and the Q output is inverted to "Low", so the AND Circuit (AN4g
) will be completely closed.

Contrary to the above, the circuit (
13') outputs a "High" signal to circuit tc], AND circuit (AN41), 17 circuit (OR40)
Both outputs become Higb°', and the motor drive circuit (M
DR) reverses the motor (MO) to extend the photographing lens. When the photographing lens reaches the focal position for the infrared light 1, the terminal [CI output or 'Low
``'', and the output of the terminal (bl) becomes ``High''.As a result, the output of the AND circuit (AN 41) becomes ``Low'', but the output of the flip-flop (FF40
) is set by the pulse from the one-shot throat circuit (O840) and its Q output becomes "'High"'.
The output of the AND circuit (AN43) is also “”)-1i gh
``'', therefore, the output of the OR circuit (OR40) is kept at ``+ (high''). As a result, the motor drive circuit (MDR) continues the reverse rotation of 7-1 (MO). The photographing lens is further extended beyond the in-focus position for infrared light.

Then, the pulses output from the encoder (EN) of the number corresponding to the amount of reverse rotation of the motor (MO) at this time are counted by the counter (ω40), and the rotation (
When the output of ω40) matches the ΔIR signal read by the reading circuit (DR), the output of the comparison circuit (DC) is reversed from 'High' to 'Low', and the motor (MO) The drive stops. That is, this completes the focus adjustment of the photographic lens to the in-focus position for visible light.

On the other hand, when focus detection is performed using visible light, the circuit (13
Even if a "High" signal is output to the terminal fbl of the terminal fbl, the output of the discrimination circuit (11) is "Low"
The output of the AND circuit (AN42) is “l LOWl1
As it is, the one-shot circuit (O54o) does not generate a pulse and the flip-flop (FF < 0) is not set. Therefore, the output of the terminal (al or fcl) of the circuit (13') changes from "High" to ILOWI+,\
By reversing, the motor (MO) stops driving,
Focus adjustment of the photographic lens to the focal position for visible light is completed.

The outline and embodiments of the focus detection device of the present invention have been described above with reference to FIGS. 1 to 8, but in this invention,
ΔIR is not limited to that expressed by the above formula ΔIR−ΔI Ro −d/n, but can be expressed by the same interchangeable lens depending on the optical path length difference between visible light and infrared light within the focus detection optical system. will also have different values.

Effects As is clear from the above explanation, according to the camera focus detection device of the present invention, even when visible light is weak, the focusing state of the photographing lens for visible light can be determined by detecting the focus using infrared light. This enables focus detection over a wider range than conventional focus detection devices that only detect focus using visible light. Further, when detecting focus using infrared light, the signal indicating the focus adjustment state of the photographing lens for infrared light is corrected using the signal indicating the amount of deviation of the focal position of the photographing lens for visible light and infrared light. The above-mentioned focus adjustment state of the photographing lens for visible light can always be detected with high precision. Further, it is determined whether focus detection is to be performed using the output of the first photoelectric conversion means that receives visible light or the output of the second photoelectric conversion means that receives infrared light. Swords made by simply determining size)
The method of discrimination is simple and suitable for practical use.

[Brief explanation of the drawing]

Fig. 1fA) is a block diagram showing an overview of the focus detection device of the present invention, Fig. 1(B) is a diagram showing a specific example of a focus detection optical system in an interchangeable lens type eye reflex camera, and Fig. 2 Figure fA) is a diagram showing the relative reflectance of the first reflecting surface of the Al beam splitter and the relative spectral sensitivity of the photoelectric conversion means; the direction of the second figure is the direction of the first figure.
Figures 3 to 7 show a first embodiment in which the focus detection device of the present invention can be intersected with a lens. 3 is an overall circuit diagram, FIG. 4 is a circuit diagram showing the configuration of the interface circuit and data output path in FIG. 3, and FIGS. 5 and 6 are data output circuits of the interchangeable lens, respectively. 7 is a flowchart showing the operation of the first embodiment, FIG. 8 is a diagram showing the main part of the circuit structure of the second embodiment of the present invention, and FIG. 9 is a diagram showing the visible light Another circuit example of a focus adjustment device for an interchangeable lens camera that discriminates the output of the photoelectric conversion means for infrared light and the output of the photoelectric conversion means for infrared light, and adjusts the focus of the photographing lens based on the output of the larger one. FIG. +21-Photographing lens, (9a) (9b)-1st, 2nd
photoelectric conversion means, (IRI)) (VSD)...
Photoelectric conversion means for monitors (IRC) (VSC)
・Photoelectric conversion means for focus detection, +61f7+ (sa)
(81)) Focus detection optical system, (11) Discrimination means, (12) Selection circuit, (16) (LDO)
Data output means, (13)... Focus detection calculation means, (13-1)... Gate circuit, (13-2)...
Arithmetic circuit, (13-3) Addition/subtraction circuit, (17
)・Reading circuit. Applicant: Minolta Camera Co., Ltd., Osaka Kokusai Building, Minolta Camera Co., Ltd., 2-30 Azuchi-cho, Higashi-ku, Osaka Inventor: Shuzo Matsushita, Osaka Kokusai Building, Minolta Camera Co., Ltd., 2-30 Azuchi-cho, Higashi-ku, Osaka City

Claims (1)

[Scope of Claims] 1. First and second photoelectric conversion means, which guide the visible light of the subject light that has passed through the photographic lens to the first photoelectric conversion means, and convert the visible light of the subject light that has passed through the photographic lens to the first photoelectric conversion means; a focus detection optical system that guides light to the second photoelectric conversion means, and a discrimination means that compares the outputs of the first and second photoelectric conversion means to determine the magnitude thereof and outputs a discrimination signal; When the discrimination means outputs a first discrimination signal indicating that the output of the first photoelectric conversion means is larger than the output of the second photoelectric conversion means, the output of the first photoelectric conversion means is output. However, when the discrimination means outputs a second discrimination signal indicating that the output of the second photoelectric conversion means is larger than the output of the first photoelectric conversion means, the first photoelectric conversion means the first discrimination signal is output from the discrimination means; Sometimes, based on the output of the first photoelectric conversion means outputted by the selection circuit, when the second discrimination signal is outputted from the discrimination means, the output of the second photoelectric conversion means outputted by the selection circuit is determined. It is characterized by comprising focus detection calculation means for detecting the focus adjustment state of the photographing lens for visible light based on the output and a signal indicating the data on the amount of deviation outputted by the data output means. Camera focus detection device. 2. The data output means is provided on an interchangeable lens having the photographic lens, and the camera to which the interchangeable lens is attached is provided with a reading means for reading the signal from the data output means. A focus detection device for a camera according to claim 1. 3. The focus detection calculation means passes the output of the reading means when the first discrimination signal is output from the discrimination means, and reads the output when the second discrimination signal is output from the discrimination means. a gate circuit for prohibiting the passage of the output from the means; and a gate circuit for prohibiting the passage of the output from the means;
or outputs a signal indicating the amount and direction of focus shift of the photographing lens based on the output of the second photoelectric conversion means, and the output from this arithmetic circuit and the gate circuit. 3. The camera focus detection device according to claim 2, further comprising an addition/subtraction circuit for adding or subtracting the output from the reading circuit. 4. The first and second photoelectric conversion means each include a focus detection photoelectric conversion means and a monitor output photoelectric conversion means,
The discrimination means is configured to receive the output of the monitoring photoelectric conversion means of the first and second photoelectric conversion means, and the selection means is configured to receive the output of the monitoring photoelectric conversion means of the first and second photoelectric conversion means. A focus detection device for a camera according to any one of claims 1 to 3, characterized in that the output of the photoelectric conversion means for focus detection is input. 5. The first and second photoelectric conversion means each consist of a focus detection photoelectric conversion means, and the outputs of the focus detection photoelectric conversion means are input to the discrimination means and the sorting means. A focus detection device for a camera according to any one of claims 1 to 3, characterized in that: