JP2000292682A - Automatic focus adjustment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive automatic focus adjustment device with high focusing precision even under an artificial light source. SOLUTION: Subject images are imaged by a pair of imaging optical systems arranged with photometric circuits 66 and remote-control receiving parts 65 in respective imaging faces. Focus adjustment information for a photographing lens is output based on a positional relation between the subject images imaged on the circuits 66 and the receiving parts 65 respectively. The photographing lens is driven by a motor driving circuit 69 and a motor 68 based on the focusing information. The focus adjustment information is corrected by a CPU 50, in response to respective photometric values in a visible-light photometric circuit inside the photometric circuit 66 and an infra-red photometric circuit inside the receiving part 65 having main sensitivities respectively in a visible light region and an infra-red region of a subject beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic focus adjusting device for detecting a focus state or a distance of an object to be measured from a positional relationship between a pair of images formed on a pair of light receiving element arrays and adjusting the focus of a photographing lens. Things.

[0002]

2. Description of the Related Art Conventionally, there has been developed a technique for detecting the luminance and background light of a subject at the time of photographing and performing correction at the time of distance measurement. For example, Japanese Patent Application Laid-Open No. 9- 211306 discloses that a focus state of a measurement target is detected from a positional relationship between a pair of images formed on a pair of light receiving element arrays, and the focus of a photographing lens is adjusted according to the detection result. There is disclosed a so-called phase difference AF (autofocus) type automatic focus adjustment device.

Further, Japanese Patent Publication No. 1-45883 discloses that
There is disclosed a technique for detecting a ratio of visible light to infrared light of a subject light beam incident on a photographing lens and correcting a focus position of the photographing lens according to the ratio.

[0004]

However, in the apparatus described in Japanese Patent Application Laid-Open No. 9-211306, when an object is illuminated with an artificial light source such as a fluorescent light or an incandescent light, the focus is reduced. Due to the aberration of the detection optical system, a difference occurs in the image position on the light receiving element from that in the case of being illuminated with natural light. This difference has a problem that it causes an error in focus position (out of focus).

In the technique described in Japanese Patent Publication No. 1-48833, a device for detecting infrared light is provided separately from a device for detecting visible light, so that the number of parts is increased and the cost is increased. Met.

The present invention has been made in view of the above problems, and has as its object to provide an inexpensive automatic focusing apparatus which has good focusing accuracy even under an artificial light source other than natural light.

[0007]

That is, the present invention provides a pair of image forming optical systems for forming an image of a subject, light receiving means arranged on each image forming surface of the image forming optical system, and the pair of image forming optical systems. Output means for outputting focus adjustment information of the taking lens from the positional relationship of the subject image formed on each of the light receiving means,
A drive unit for driving the photographing lens based on the focus adjustment information, wherein the automatic focus adjustment device is provided separately from the light receiving unit, and the visible light region and the infrared light region of the subject light flux are provided. The first having the main sensitivity in the light region
And a second light metering means, and a correcting means for correcting the focus adjustment information according to respective light metering values of the first and second light metering means.

In the automatic focusing apparatus according to the present invention, a subject image is formed by a pair of image forming optical systems in which light receiving means are arranged on each image forming surface. Then, based on the positional relationship between the subject images formed on each of the pair of light receiving units, focus adjustment information of the photographing lens is output by the output unit. The photographing lens is driven by a driving unit based on the focus adjustment information. Further, first and second photometric means having main sensitivities in the visible light region and the infrared light region of the subject light beam are provided separately from the light receiving means, and the first and second photometric devices are provided. The focus adjustment information is corrected by the correction means according to the respective photometric values of the means.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2A to FIG. 2C and FIG.
(C) shows the appearance of the camera according to the first embodiment of the present invention in three views. This camera has a single-lens reflex method and a system capable of arbitrarily setting various photographing modes.

As shown in FIG. 2A, a power switch 1, a strobe 2, a release button 3, and the like are provided on an upper surface of the camera.

The power switch 1 is a power switch, and the switch is turned on by a slide operation to a predetermined position to enable the camera to take a picture. Strobe 2 is
Normally, a strobe unit is stored and provided in the head of the main body, and is used by releasing the locking of the spring bias as necessary and starting up. The release button 3 allows the shirt release,
This is a switch for performing a shooting operation.

The front part 2 of the camera is provided with a self / remote control window 4 and a photographing lens 5, as shown in FIG.

The self / remote control window 4 is a window provided for turning on and blinking an internal LED during a self-timer operation to indicate the self-timer operation to a photographer. The self / remote control window 4 is also a window for receiving a remote control signal by an infrared light receiving element stored inside.

As shown in FIG. 2C, the lower surface of the camera is provided with a tripod screw 6, a film rewind button 7,
Battery cover opening / closing lever 8, battery cover 9, cartridge cover 10,
A lock lever 11 and the like are provided.

The tripod screw 6 is a screw hole which is screwed with a screw provided on the tripod when fixing the camera to the tripod. The midway rewind button 7 is a switch operated to rewind the film when taking out the film in the middle of shooting.

The battery cover opening / closing lever 8 is a lever for opening and closing the battery cover 9 when replacing the battery. The cartridge lid 10 opens and closes when a film cartridge (not shown) is loaded into the camera. Further, the lock lever 11 is a lever for mechanically detecting that the film cartridge is loaded in the camera.

As shown in the side views of FIGS. 3A and 3B, strap mounting portions 12 and 15 are provided on the side of the camera. These strap attachment parts 1
Holes for passing straps (not shown) are formed in 2 and 15.

FIG. 3C is a rear view of the camera. As shown in FIG. 3C, on the back of the camera, a finder window 16, a print type switching knob 17, a zoom lever 18, a liquid crystal display panel 19, and a diopter adjustment knob 2 are provided.
0, strobe mode button 21, self / remote control button 2
2. A backlight correction button 23, a full auto button 24, an image select button 25, a date set / write button 26, a date mode button 27, and the like are provided.

The finder window 16 is capable of observing an image from the photographing lens 5 by a single-lens reflex method and also partially confirming information of a predetermined photographing mode within the field of view of the finder. .

The print type switching knob 17 is a lever for switching the photographing screen to several types, and is linked with the display inside the finder window 16. The zoom lever 18 is a button for changing the focal length of the camera,
It is composed of two switches, a zoom-up switch and a zoom-down switch, and is a seesaw switch.

The liquid crystal display panel 19 is for displaying and outputting various information of the camera. Diopter adjustment knob 20
Is a knob for adjusting the viewfinder screen so as to be appropriately viewed in accordance with the eyesight of the photographer.

The strobe mode button 21 is used for the strobe 2
Is a mode button for setting the light emission mode. The self / remote control button 22 is a mode button for setting a self-timer mode and a remote control shooting mode. Also, the backlight correction button 23
Is a button for correcting overexposure in backlight.

Full auto button 24, image select button 2
Reference numeral 5 denotes a button for selecting and setting five photographing modes, and includes a mode setting button composed of a switch group. 1
One switch is assigned to one shooting mode, and one touch allows, for example, five kinds of shooting modes, for example, “landscape mode”, “portrait mode”, “stop action mode”, “night scene mode”, and “full auto mode”. One can be selected from "mode". These select button groups are buttons for switching a plurality of predetermined photographing modes, and select a desired mode for photographing in accordance with photographing conditions.

The date set / write button 26 is used for operating the data to be advanced by "1" at the time of date correction, and for illuminating the display panel with the backlight provided on the liquid crystal display panel 19. This is a switch that also functions as a button.

Further, the date mode button 27 is a switch that serves both as a button for switching a recording mode of date information and a button for switching to a mode for correcting date information. Each time the date mode button 27 is pressed, the recording mode is switched. When the user wants to set the mode for correction, the date information blinks by pressing and holding the date mode button 27 for more than 2 seconds, for example.
The correction can be performed by the light button 26, and the next information can be corrected by pressing the date mode button 27. By continuing these operations, the date information is corrected.

FIG. 4 is an enlarged view for explaining the display on the liquid crystal display panel 19 described above.

In FIG. 4, a mark 31 indicates the number of photographed frames,
This is an area for displaying the number of frames that can be photographed and the file sensitivity, and the mark 32 indicates the remaining amount of the battery.
The marks 33 and 35 indicate a shooting mode, the mark 33 indicates that the shooting mode is a full auto mode, and the mark 35 indicates which of the image select modes is selected. It is. The mode to be selected is the full auto button 24,
The image is displayed corresponding to each of the image select buttons 25.

The mark 36 is a notation for indicating that the mode is the backlight correction mode. Furthermore, mark 37
Is a notation for indicating that the mode is the self-timer shooting mode or the remote control shooting mode.

The mark 38 is a date data display area. Then, the mark 39 is turned on when the information shared and displayed in the number-of-shots area of the mark 31 is the number of frames that can be shot. The mark 40 is turned on when the information shared and displayed in the number-of-shots area of the mark 31 is the film sensitivity. Furthermore, mark 41
Is turned on when the film cartridge is loaded in the camera.

FIG. 1 is a block diagram showing a schematic configuration of a camera according to a first embodiment of the present invention.

Referring to FIG. 1, this camera has an arithmetic and control circuit (CPU) 50 composed of a one-chip microcomputer or the like for controlling the sequence of the entire camera, and a configuration which will be described later based on a control signal from the CPU 50. Controlling the parts, etc., and generating a voltage VLCD with little temperature dependence,
And an interface IC (IFIC) 51 for generating a VT that depends on the absolute temperature. These CP
The U50 and the IFIC 51 exchange data with each other by 4-bit parallel communication.

The CPU 50 includes a clock section 52 for providing a clock signal serving as a reference for timing when the CPU 50 performs a control operation, and a rewritable nonvolatile memory for storing data and the like described later, for example, an EEPROM 53.
And an external connection terminal 54, which will be described later, and a liquid crystal which notifies the photographer of the operation status of the camera and is arranged on the back cover side of the camera (not shown) to display the number of frames of the film, the strobe mode, the remaining battery level, and the like. A display panel (LCD) 19, an AF circuit 61, an aperture driving circuit 83, and various switches described later are provided.

The EEPROM 53 stores various correction values and adjustment values necessary for the CPU 50 to perform various controls, data such as the number of film frames, and correction values for artificial light discrimination, and communicates with the CPU 50. The external connection terminal 54
The communication line between the CPU 50 and the EEPROM 53 can be connected to the outside. An external adjuster, a checker, or the like is connected to the external connection terminal 54 to control the camera from the outside.
3 can be read or written.

The AF circuit 61 is a circuit for obtaining the amount of movement of the focusing lens from the phase shift of the image passing through the photographing lens, and is a so-called TTL passive system of the TTL phase difference system.

The aperture driving circuit 83 is a circuit for driving a stepping motor (not shown) to open and close an aperture (not shown).

The various switches described above are as follows. That is, the main switch (PWSW) 1
Is a switch for bringing the camera into an operating state, and a back cover switch (BKSW) 55 is linked with opening and closing of the back cover of the camera,
A switch for turning on / off. This back cover switch 55
Starts automatic film loading when it detects that the back cover of the camera is closed, that is, it is turned on from off.

Further, a first release switch (1RSW)
Reference numeral 56 denotes a switch that is turned on when the release button 3 is half-pressed. When the switch is turned on, the camera performs various calculations such as distance measurement and photometry in a preset shooting mode. Also, the second release switch (2RSW) 57
This switch is turned on when the release button 3 is fully pressed. When the switch is turned on, exposure to the film, winding of the film, and the like are performed based on the calculation result.

Self-timer switch (SELFSW) 5
8 is the shooting mode, which is about 10 seconds after the release button 3 is pressed.
This is a switch for switching to so-called self-timer shooting in which an exposure operation is performed after a predetermined time of about seconds. By turning on the second release switch 57 while turning on the self-timer switch 58, shooting in the self-timer mode can be performed.

A flash switch (FLSW) 59
Is a switch for switching the flash mode at the time of shooting. In the camera according to the present embodiment, the strobe mode is set to “OFF (strobe emission prohibited)”, “FILL-I”.
N (flash forced emission) "," AUTO (camera determines the shooting conditions and controls on / off of flash emission) "," AUTO-S (auto mode with red-eye reduction function added) ", And the mode is switched each time the strobe switch 59 is turned on.

Then, a film rewind switch (RWS)
W) 60 is a switch for forcibly rewinding the film. By turning on the film rewind switch 60, the film can be rewound even if the film has not been shot to the last frame.

The 1FIC 51 has a film information reading section 6 for reading information recorded on the magnetic recording section of the film.
3, a remote control receiving unit 65 for receiving a signal of infrared light projected from a remote control 64 of the photographer, etc., a photometric circuit 66 that divides a photographing screen and can measure each of them, and a shutter that opens and closes a shutter. By driving the drive circuit 67 and the motor 68 and its associated power transmission mechanism (not shown) in forward and reverse directions, control of film winding, rewinding, mirror up and down, shutter charging, focusing operation, lens driving, and the like is performed. A motor driving circuit 69 and a self-timer LED (SELFL) for displaying a signal to notify the subject by lighting that the camera is performing self-timer shooting.
ED) 70 and a photoreflector (WPR) 7 described later.
1 is connected.

The remote control receiving section 65 includes a remote control 64
Receiving the infrared light signal projected from the
Send to The IFIC 51 receives it, performs waveform shaping, and transmits it to the CPU 50. The remote control receiver 65 also performs artificial light discrimination, as will be described later in detail.

The photometric circuit 66 is a circuit for converting the brightness of a subject into an electric signal by using a sensor capable of separately measuring the light intensity at a central portion and a peripheral portion of the photographing screen. This electric signal is processed in IFIC 51 and
Sent to U50. The sensor in the photometric circuit 66 can separately measure the light in the central portion and the peripheral portion of the shooting screen.
It is also possible to perform backlight determination based on the photometry of only the central portion or the difference between the outputs of the two in accordance with the purpose of photographing. Furthermore, it is also used for artificial light detection described later.

The shutter drive circuit 67 includes an IFIC5
The shutter is opened and closed in response to a control signal from the control unit 1. Although not shown, the shutter in the present embodiment uses, for example, a focal plane shutter.

The photo reflector 71 emits light to a perforated portion of a film loaded in a camera, and detects reflected light to detect the presence or absence of perforation, and to detect a film feed amount. It is. The signal indicating the presence or absence of the perforation is
The waveform is shaped by the IFIC 51 and sent to the CPU 50. The photoreflector 71 uses a voltage source VLCD with low temperature dependence to improve the accuracy of detecting the presence or absence of perforation.

Further, the CPU 50 and the IFIC 51 are provided with the following parts, respectively.

As a power supply for driving this camera, for example, a power supply line Vcc1 directly supplied from a 6V battery
5V which is insufficient for operating the entire circuit
A boosting circuit 74 that generates a secondary voltage that is boosted to supply the secondary voltage to the secondary voltage line Vcc2, a light emitting tube that irradiates the subject to be photographed with auxiliary light, and a strobe circuit 75 that controls the light emitting tube.

Also, under the control of the CPU 50, when the relays button 3 is half-pressed, an AF display LED 76 which lights up when focusing is possible and blinks when focusing is not possible to call attention to the photographer is provided. , Is controlled by the IFIC 51, lights when the flash 2 is in a light emitting state when the relays button 3 is half-pressed, and the flash 2 can emit light even though the camera determines that the strobe 2 is necessary. If not, a flash warning LED 77 that flashes to alert the photographer and an AF display LED beside the finder window 16 are provided.
A finder display device 78 in which an ED 76 and a strobe warning display LED 77 are arranged is provided.

Further, between the CPU 50 and the IFIC 51,
A photo interrupter (AVPI) 79, a photo reflector (CLPR) 80, and an MTP for generating a pulse output
I81.

Of these, the photo interrupter 7
Numeral 9 is for detecting the narrowing of the aperture. When the narrowing down is started, the member that shields the light between the slits of the photo interrupter 79 retreats, the output of the photo interrupter 79 becomes “L level”, and is sent to the IFIC 51. Based on this signal, the CPU 50 controls the aperture of the stop.

The photo reflector 80 is for detecting the position of a clutch mechanism (not shown) for switching where the power of the motor 68 is transmitted. still,
The photo interrupter 79 and the photo reflector 80
Since they are not driven simultaneously in sequence control, some signal lines are shared.

The MTPI 81 generates a pulse output when the light-shielding blade 82 linked to the motor 68 rotates, and sends the pulse output to the CPU 50. This pulse is used for controlling the lens extension amount.

Next, detection of artificial light by the camera configured as described above will be described.

The artificial light detection according to the present embodiment is performed using the remote control receiving unit 65 and the photometric circuit 66.

FIG. 5 is a diagram showing spectral sensitivity characteristics of a photometric sensor for detecting light in a natural light region and a remote control sensor for detecting light in an infrared light region, which are used in the camera of the present embodiment. is there.

As shown in FIG. 5, the photometric sensor
The remote control sensor has a spectral sensitivity characteristic closer to a short wavelength with a peak near 0 nm, and the remote control sensor has a spectral sensitivity characteristic closer to a long wavelength with a peak near 1000 nm.

FIG. 6 is a schematic diagram of spectral characteristics depending on the difference between various light sources. As shown in FIG. 6, the light of the fluorescent lamp is
With the peak around 600 nm as the peak,
It can be seen that it is in the range around 00 nm.

This spectral characteristic causes a bluish color when a film is printed. The incandescent lamp has a peak near 1000 nm and a longer wavelength than around 300 nm. This is what causes the film to have a reddish color when printed.

In general, it can be seen that natural light is in a relatively entire range closer to longer wavelengths than around 300 nm.

As can be seen from FIGS. 5 and 6,
Since each sensor is originally used for a different purpose, it is designed to detect signals of different wavelengths to prevent malfunction.

Therefore, since each sensor can only sense light within the range of the spectral characteristics, if the light source included in the ambient light is, for example, a fluorescent light, the photometric sensor can detect that light. The remote control sensor can hardly detect the light of the fluorescent lamp.

Similarly, in the case of an incandescent light bulb, the remote control sensor senses light more than the photometric sensor, and the sensitivity of the photometric sensor is slightly higher for natural light.
In any case, it is possible to sense light.

Next, the actual processing of artificial light detection will be described.

FIG. 7A is a diagram showing the configuration of the remote control receiving unit 65 and the photometric circuit 66 used for artificial light discrimination.

The remote control receiving section 65 includes a light receiving lens 84 for condensing light for illuminating the subject, and a remote control sensor (light receiving element) 8 for detecting the condensed light and converting it into a photocurrent.
5 and an infrared photometric circuit 86. The infrared photometric circuit 86 includes a capacitor 87 provided in a feedback loop for integrating the photocurrent, a comparator 88 for comparing the output of the remote control sensor 85 with a first predetermined reference level and outputting the same. , This comparator 88
, And a comparator 90 for comparing and outputting a second predetermined level as a reference, and a switch 8 for controlling a SW signal from the CPU 50 to initialize a capacitor 87.
9.

With this configuration, the light condensed by the light receiving lens 84 is applied to the remote control sensor 85 to be converted into a photocurrent, and is integrated by the capacitor 87 provided in the feedback loop of the comparator 88. When the switch 89 is turned off, the output V
When int falls from the first predetermined level Vref1 and falls below the second predetermined level Vref2 as shown in FIG. 7B, the output COMP of the comparator 90 changes the inverted signal to C
Output to PU50.

Here, the time Tint from when the switch 89 is turned off to when the comparator 90 is inverted is proportional to the reciprocal of the intensity of the light incident on the remote control sensor 85. As shown in FIG. 5, the spectral sensitivity characteristic of the remote control sensor 85 senses light in the infrared region, and the intensity of incident light here is mainly infrared light, that is, incandescent lamps. Light quantity. Therefore, the CPU 50 can measure the amount of infrared light by counting the time Tint by the built-in counter.

The configuration of the photometric circuit 66 for processing visible light is different in that a photometric sensor 92 is used instead of the remote control sensor 85 of the remote control receiving section 65 described above, and the other configurations are the same. That is, the photometric circuit 6
6 includes a light receiving lens 91, a photometric sensor 92, and a visible light photometric circuit 93. Since the light in the visible light range shown in FIG. 5 is sensed, the intensity of the incident light here is the amount of visible light, that is, the amount of light mainly from a fluorescent lamp.

Next, referring to the flowchart of FIG.
The operation of the camera according to the present embodiment will be described.

The operation until the first release switch 56 is pressed is a well-known technique, and the description is omitted here.

When the first release switch is detected, the photometry circuit 66 performs photometry of visible light in step S1. Next, in step S2, the remote control receiving unit 65 performs infrared photometry.

In step S3, a photometric calculation is performed from the photometric values of the visible light and the infrared light obtained by the photometric circuit 66 and the remote control receiving unit 65. Then, step S
At 4, a subroutine "artificial light source detection" is performed.

FIG. 9 is a flow chart for explaining the operation of the subroutine "artificial light source detection".

When the "artificial light source detection" subroutine is entered, the photometric values detected by the remote control receiver 65 and the photometric circuit 66 are compared in step S21.
That is, a photometric value of the visible light measured by the photometric circuit 66, a value predetermined value C ₁ is added to the measured infrared photometric value by the remote control reception section 65 are compared. As a result of this comparison, when the photometric value (for visible light) is larger (Y
ES), it is determined that the influence of the illumination by the fluorescent lamp is large, and the process returns to step S25 after setting the light source to the fluorescent lamp.

On the other hand, if it is determined in step S21 that the visible light photometric value is smaller, the process proceeds to step S22, where the value obtained by adding the predetermined value C ₂ to the visible light photometric value and the infrared photometric value is used. Are compared. Here, if the visible light photometric value is larger (YES), it is determined that the influence of the illumination by the incandescent lamp is large, the process proceeds to step S24, the incandescent lamp is used, and the process returns.

[0077] In step S22, if the predetermined value C ₂ to the infrared photometric value than the visible light photometric value was greater added value (NO), the influence of in artificial light illuminating an object Is determined to be small, and the process returns to step S23 after the light source is set to natural light.

The above-mentioned predetermined values C ₁ and C ₂ are correction values for making the above-mentioned judgment correct.
Since the information is stored in advance in the EPROM 53 or the like, correction, adjustment, and the like can be easily performed.

Furthermore, in this sequence, natural light, incandescent light and fluorescent light are determined as a result. However, as can be seen from the flowchart, two types of detection, only artificial light or natural light, are also possible.

Returning to the flowchart of FIG. 8, when the detection of the artificial light source is completed in step S4, the process proceeds to step S4.
At 5, the phase signal is detected from the AF circuit 61, and the distance measurement is performed. Next, in step S6, a phase difference is obtained from the phase signal, and the amount of displacement of the focusing lens (photographing lens) is calculated.

Then, in steps S7 and S8,
According to the determination of the "artificial light source detection" subroutine in step S4 described above, the light sources are classified by light source. That is, when it is determined that the light is natural light, the process proceeds to step S9, and the drive amount correction value of the focusing lens is set to “0”. Similarly, when it is determined that the lamp is incandescent, the process proceeds to step S10, and the drive amount correction value of the focusing lens is set to “α”. When it is determined that the lamp is a fluorescent lamp, the process proceeds to step S11 to perform focusing. The lens drive amount correction value is set to “β”. These correction values are stored in the EEPROM 53 in advance.

Thereafter, in step S12, the driving amount of the focusing lens is calculated. Here, when the light source is an artificial light source, the drive utilization calculation is performed using the correction value α or β obtained in step S10 or S11.

Next, in step S13, the drive amount calculated in step S12 is compared with a predetermined value. As a result, if the drive amount has not reached the predetermined value, the process shifts to step S14 to drive the focusing lens. Then, the process proceeds to step S5, and step S1
Steps S5 to S14 are repeated until the drive amount reaches a predetermined value in 3, that is, until the drive amount is within a focusable range.

If the drive amount has reached the predetermined value in step S13, it is determined that the depth of field is in which focus can be achieved, and the flow advances to step S15 to determine the state of the first release switch 56. . Here, if the first release switch 56 is off, the present sequence ends. On the other hand, if the first release switch 56 is on, the process proceeds to step S16.
Then, the state of the second release switch 57 is determined.

In step S16, if the second release switch 57 is off, the process proceeds to step S15. If the second release switch 57 is on, the process proceeds to step S17 to perform an exposure operation. Thereafter, the present sequence ends.

As described above, according to the first embodiment,
A correction value corresponding to the artificial light source is obtained by using the remote control receiving unit 65 and the photometric circuit 66, and the distance measurement calculation is performed with the driving amount using the correction value. Can be better.

Next, a second embodiment of the present invention will be described.

The second embodiment is different from the above-described first embodiment only in the operation after the first release is detected, and the other configurations and operations are the same as those in the first embodiment. Therefore, the description is omitted.

FIG. 10 is a flowchart for explaining the main operation of the camera according to the second embodiment.

In the flowchart of FIG. 10, steps S31 to S35 and steps S42 to S47 are the same as steps S1 to S5 in the flowchart of FIG.
Since the processing is the same as that of steps S12 to S17, the description is omitted.

When the distance measurement is performed in step S35, in subsequent steps S36 and S37, step S34 is performed.
According to the judgment of the "artificial light source detection" subroutine, each light source is classified. That is, when it is determined that the light is natural light, the process proceeds to step S38, and the correction value of the reference two image interval is set to “0”. Similarly, if it is determined that the lamp is incandescent, the process proceeds to step S39, where the correction value for the reference two image interval is set to “α”.
The flow shifts to 40, where the correction value for the reference two image interval is set to “β”. These correction values are stored in the EEPROM 53 in advance.

Then, a distance measurement calculation is performed in step S41. Here, the shift amount of the focusing lens (photographing lens) is calculated from the phase difference obtained from the phase signal and the reference two image interval using the correction value. Thereafter, in step S42, the driving amount of the focusing lens is calculated.

Even if such an operation is performed, the first
The same effect as that of the embodiment can be obtained.

According to the above embodiment of the present invention,
The following configuration can be obtained.

(1) A pair of image forming optical systems for forming an image of a subject, a pair of light receiving means arranged on each image forming surface of the image forming optical system, and a pair of light receiving means, respectively. An automatic focus adjustment device comprising: an output unit that outputs focus adjustment information of a photographing lens from a positional relationship of a formed subject image; and a driving unit that drives the photographing lens based on the focus adjustment information. A first and a second photometric means provided separately from the light receiving means and having main sensitivities in a visible light region and an infrared light region of the subject light flux, respectively;
An automatic focus adjustment device comprising: a correction unit that corrects the focus adjustment information in accordance with respective photometric values of the first and second photometric units.

(2) The correction means determines the type of light source illuminating the subject by comparing the outputs of the first and second photometric means, and outputs the focus adjustment information according to the result of the determination. The automatic focusing device according to the above (1), wherein the automatic focusing device performs the correction.

(3) The automatic focusing device according to (1) or (2), wherein the second photometric means is a remote control sensor for receiving a remote control signal.

(4) The automatic focus adjustment apparatus according to (1), wherein the focus adjustment information is a drive amount of the photographing lens.

(5) The automatic focus adjustment apparatus according to (1), wherein the focus adjustment information is reference phase difference information of the photographing lens.

(6) A pair of image forming optical systems for forming an image of a subject, a pair of light receiving means arranged on each image forming surface of the image forming optical system, and each of the pair of light receiving means. In a camera comprising: output means for outputting focus adjustment information of a photographing lens based on a positional relationship of an imaged subject image; and drive means for driving the photographing lens based on the focus adjustment information. First and second photometric means, which are provided separately from the means and have main sensitivities in the visible light region and the infrared light region of the subject light flux, respectively;
And a correcting means for correcting the focus adjustment information according to respective photometric values of the second photometric means.

(7) The correction means determines the type of light source illuminating the subject by comparing the outputs of the first and second photometric means, and outputs the focus adjustment information in accordance with the result of the determination. The camera according to the above (6), wherein the correction is performed.

(8) The camera according to (6) or (7), wherein the second photometric means is a remote control sensor for receiving a remote control signal.

(9) The camera according to (6), wherein the focus adjustment information is a driving amount of the photographing lens.

(10) The camera according to (6), wherein the focus adjustment information is reference phase difference information of the photographing lens.

[0105]

As described above, according to the present invention, it is possible to provide an inexpensive automatic focusing apparatus which has good focusing accuracy even under an artificial light source.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a camera according to a first embodiment of the present invention.

FIGS. 2A and 2B show the appearance of a camera according to a first embodiment of the present invention, wherein FIG. 2A is a top view, FIG.
(C) is a bottom view.

3A and 3B show the appearance of the camera according to the first embodiment of the present invention, wherein FIG. 3A is a side view showing the right side of the camera;
(B) is a side view showing the left side of the camera, and (c) is a rear view.

FIG. 4 is an enlarged view for explaining display on the liquid crystal display panel 19.

FIG. 5 is a diagram illustrating spectral sensitivity characteristics of a photometric sensor that detects light in a natural light region and a remote control sensor that detects light in an infrared light region, used in the camera of the first embodiment. .

FIG. 6 is a schematic diagram of spectral characteristics according to differences in various light sources.

7A is a diagram showing a configuration of a remote control receiving unit 65 and a photometric circuit 66 used for artificial light discrimination, and FIG. 7B is a characteristic diagram of a switch 89, an output Vint of a comparator 88, and an output COMP of a comparator 90. It is.

FIG. 8 is a flowchart illustrating a main operation of the camera according to the first embodiment.

FIG. 9 is a flowchart illustrating an operation of a subroutine “artificial light source detection”.

FIG. 10 is a flowchart illustrating a main operation of the camera according to the second embodiment.

[Explanation of symbols]

 1 power switch (PWSW), 2 strobe, 3 release button, 16 finder window, 19 liquid crystal display panel, 21 strobe mode button, 50 arithmetic control circuit (CPU), 51 interface IC (1FIC), 52 clock section, 53 nonvolatile Memory (EEPROM), 54 External connection terminal, 55 Back cover switch (BKSW) 56 First release switch (1RSW), 57 Second release switch (2RSW), 58 Self-timer switch (SELFSW), 59 Strobe switch (FLSW) , 60 film rewind switch (RWSW), 61 AF circuit, 63 film information reading section, 64 remote control, 65 remote control receiving section, 66 photometry circuit, 67 shutter drive circuit, 68 motor, 69 motor drive circuit, 70 self-timer L D (SELFLED), 71 Photoreflector (WPR), 74 Boost circuit, 75 Strobe circuit, 76 AF display LED, 77 Strobe warning display LED, 78 Viewfinder display device, 79 Photointerrupter (AVPI), 80 Photoreflector ( CLPR), 81 MTPI, 83 aperture drive circuit.

Claims (3)

[Claims] 1. A pair of image forming optical systems for forming an image of a subject, light receiving means arranged on each image forming surface of the image forming optical system, and a subject formed on each of the pair of light receiving means. An output means for outputting focus adjustment information of the photographing lens from the positional relationship of the image; and a driving means for driving the photographing lens based on the focus adjustment information. First and second photometering means provided separately from the means and having main sensitivities in the visible light region and the infrared light region of the subject light beam, respectively; A correction means for correcting the focus adjustment information according to a value. 2. The method according to claim 1, wherein the correcting unit compares the outputs of the first and second photometric units to determine a type of a light source illuminating the subject, and corrects the focus adjustment information according to a result of the determination. The automatic focusing apparatus according to claim 1, wherein the automatic focusing is performed. 3. The automatic focusing apparatus according to claim 1, wherein said second photometric means is a remote control sensor for receiving a remote control signal.