JPH07325332A - Camera provided with light control device - Google Patents

Abstract

PURPOSE:To photograph a main object by an appropriate exposure in an always focused, or nearly focused state by controlling the stop of flashing a flash device based on the photometry result obtained by a photometry means when the flash device is flashed. CONSTITUTION:A defocus quantity for the object in five focusing zones 33a to 33e set respectively at different positions in a photographic picture frame 29 is detected by five focusing sensors in an AF multipoint focusing unit. On the other hand, a TTL direct multipoint photometry sensor is provided with photometry elements for receiving the light reflected on the object in five photometry zones 43a to 43e set at positions corresponding to respective focusing zones 33a to 33e, that is, photometry sensors 41a to 41e. Also the position of the main object in the photographic picture frame is detected by using the focusing results obtained by plural focusing means, and the photometry is executed by the photometry means corresponding to the main object position, and then, flash device is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when a flash device such as a strobe is caused to emit light, measures the amount of light reflected from a subject in a region corresponding to a predetermined distance measuring region among a plurality of distance measuring regions. The present invention relates to a camera equipped with a light control device for controlling light.

[0002]

2. Description of the Related Art A multi-point distance measuring device capable of performing distance measurement or focus detection for a plurality of regions of a field and a camera provided with a multi-point photometric device for measuring a region corresponding to a distance measuring region are known. Has been. The strobe light metering element of the camera includes a metering element having a metering area corresponding to the entire shooting screen, or a plurality of metering elements corresponding to a plurality of shooting areas.

However, since a camera equipped with this kind of multi-point distance measuring device divides the entire photographic screen according to the light measuring area, the light measuring area is much wider than the distance measuring area. Therefore, if an object with high reflectance such as a white wall or window glass is present in the background of the main subject, and the strobe is fired, the light metering element for dimming receives the strobe light reflected by these high-reflectance objects. There is a case. In this case, there is a problem that a backlit state occurs and the main subject is underexposed and proper exposure cannot be performed. Further, when the background of the main subject is very far, only the reflected light from the main subject, which occupies only a part of the photometric area, is received, and there is a possibility that the main subject is overexposed.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems and is provided with a light control device capable of controlling flash emission of a main subject by multi-point distance measurement and multi-point light metering. The purpose is to provide a camera.

[0005]

SUMMARY OF THE INVENTION The present invention which achieves this object is provided with a distance measuring means for measuring a plurality of distance measuring areas and a light measuring means for measuring an area corresponding to these distance measuring areas. Using a distance measurement result that has been measured, the position of the main subject in the shooting screen is detected, and a dimming device for dimming the flash device by photometry by the photometric means corresponding to the position of the main subject is provided. It has characteristics.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments. FIG. 1 is a diagram showing an outline of a single-lens reflex camera to which the present invention is applied.

Normally, the subject light that has passed through the taking lens 10 and has entered the camera body 20 has a portion near the optical axis of the taking lens 10 that passes through the main mirror 21 and is reflected by the sub-mirror 22 for AF multipoint. It enters the distance measuring unit 31. On the other hand, most of the subject light that has entered the main mirror 21 is reflected here, forms an image on the focusing screen 23, and is transmitted. This focusing screen 2
The subject image formed on the image 3 is observed by the photographer as an erect real image through the eyepiece lens 25 and the pentaprism 24. Further, part of the subject light that has passed through the focusing screen 23 enters a split photometric sensor 26 arranged near the eyepiece lens 25. In the description of the present embodiment, the term "distance measurement" means not the measurement of the subject distance but the measurement of the defocus amount of the image plane formed by the photographing lens 10 with respect to the film surface of the camera body 20. means.

During exposure, the main mirror 21 rises to open the photographing optical path and the shutter 27 opens. Therefore, the subject light that has passed through the taking lens 10 forms an image on the film 28, is reflected by the film 28, and enters the TTL direct multipoint photometric sensor 41 for light control. TT
The L direct multi-point photometric sensor 41 includes a plurality of photometric sensors 41a to 41e as the light control photometric means.

A built-in strobe 51 is arranged in the upper front part of the penta prism 24. This built-in flash 51
As is well known, the light emitting unit 52 moves to the illustrated light emitting position and the storage position to be housed in the camera body 20.

FIG. 2 is a block diagram showing the main part of the control circuit of this single-lens reflex camera. This camera has a control circuit 61 for controlling various operations of the camera, a focus detection circuit 63 for converting a subject image signal detected by each distance measuring sensor of the AF multipoint distance measuring unit 31 into a defocus signal,
A plurality of photometric sensors 41a to 41e of the TTL direct multipoint photometric sensor 41, a photometric circuit 65 for converting the subject brightness signal detected by the split photometric sensor 26 into a predetermined photometric brightness signal.
One of the selected photometric sensors 41a-41
A dimming circuit 67 that detects the amount of received light of e and adjusts the amount of strobe light, and a strobe circuit 6 that causes the built-in strobe 51 to emit light.
9, and an exposure control circuit 71 for driving a shutter, a mirror, a diaphragm, and the like.

FIG. 3 shows the dimming circuit 67 more specifically. Each of the photometric sensors (photodiodes) 41a to 41f constituting the TTL direct multipoint photometric sensor 41
Each base of is connected to the multiplexer 42, and the collector is connected to the non-inverting terminal of the operational amplifier 43. The multiplexer 42 receives the light receiving sensor selection signal from the control circuit (CPU) 61 and receives the corresponding one photometric sensor 4
A bias voltage is applied to the bases 1a to 41f for selection.

An integrating capacitor 44 is connected between the output terminal and the inverting terminal of the operational amplifier 43. The selected photometric sensors 41a to 41f output a current according to the intensity of the received light, the operational amplifier 43 amplifies the current, and the integration capacitor 44 integrates the amplified current. An integration switch 45 for turning on / off the integration is connected in parallel with the integration capacitor 44. When the integration switch 45 is turned on, the integration capacitor 44 is discharged and the integration operation is stopped, and when it is turned off, the integration capacitor 44 starts integration. The integration switch 45 is normally turned on, and is turned off in synchronization with the traveling of the shutter front curtain (not shown).

The integrated value of the integrating capacitor 44 is input to the inverting terminal of the comparator 47. The TTL_DA level output from the D / A converter 46 is input to the non-inverting terminal of the comparator 47. The D / A converter 46 converts the flash stop level (TTL_DA level) set by the control circuit 61 based on the ISO sensitivity Sv and the exposure correction value Xv into an analog TTL_DA level and outputs it. Therefore, when the integrated value reaches the TTL_DA level, the comparator 47 outputs a high level signal. The output of the comparator 47 is a quench signal, and the control circuit 61 which has received the quench signal stops the flash of the built-in strobe 51 in the strobe circuit 69, and when the external strobe is attached, the external strobe also emits light. Stop. The strobe circuit 69 may be configured to stop the light emission by directly inputting the quench signal from the dimming circuit 67.

As described above, the dimming circuit 67 integrates the received light amount of the selected photometric sensors 41a to 41f into the integrating circuit 43,
44, the comparator 47 compares the integrated value with a predetermined value (flash stop level TTL_DA), and when the integrated value reaches the predetermined value, the comparator 47 outputs a quench signal to output the built-in flash 51 and the external flash. Stop the flashing of.

The structure which is a feature of the present invention will be described in detail with reference to FIG. 4A and 4B are views showing the distance measuring area and the light measuring area on the photographing screen of each sensor of the AF multipoint distance measuring unit 31 and the TTL direct multipoint light measuring sensor 41, and FIG. It is a figure which shows the mode that the area | region was piled up.

The five distance measuring sensors (not shown) of the AF multi-point distance measuring unit 31 have five distance measuring areas 33a to 33 set at different positions in the photographing screen 29, respectively.
The defocus amount for the subject within e is detected. In the following description, when the term “defocus amount” is used,
The absolute value is meant. On the other hand, the TTL direct multi-point photometric sensor 41 also includes the distance measurement areas 33a to 33e.
5 photometric regions 43a to 4 set at positions corresponding to
A photometric element capable of receiving reflected light from a subject within 3e, that is, photometric sensors 41a to 41e. These distance measuring areas 33a to 33e and photometric areas 43a to 43e
Are set at overlapping positions on the photographing screen 29 (see FIG. 4C). Moreover, each of the photometric areas 43a to 43
Since e may cause overexposure if its size is large, e is set to a region slightly larger than the distance measuring regions 33a to 33e. Each of the photometric areas 43a to 43e preferably has the same size as the corresponding distance measuring areas 33a to 33e, but the photometric areas 43a to 43e may be smaller.

Further, the multipoint photometric sensor 41 of this embodiment is
A photometric sensor 41f for photometrically measuring a photometric area 43f for receiving subject light in almost the entire area of the photographing screen 29 is provided. This photometric sensor 41f is for coping when the position of the main subject cannot be selected or when the sensor with the minimum defocus amount is larger than the specified value.

Incidentally, these regions 33a to 33e, 43
The numbers and positions of a to 43f are not limited to the illustrated embodiment. The positional relationship is that the distance measuring areas 33a to 33e and the light measuring area 43 are
It is only necessary that a to 43e correspond to each other, and it is desirable that the areas of the respective regions are equal to each other or the difference between them is small. Further, the light receiving areas corresponding to all the distance measuring areas may not be present.

Next, strobe light control processing, which is a feature of the photographing operation of the single-lens reflex camera, will be described with reference to the flowcharts shown in FIGS. The processing of the illustrated embodiment is executed under the overall control of the CPU 61 based on the program written in the internal ROM of the CPU 61.

This single-lens reflex camera is provided with each distance measuring area 33a.
To 33e, the defocus amount is detected, and the light receiving sensor for light adjustment corresponding to the distance measuring sensor having a small defocus amount is selected, the strobe is caused to emit light at the time of exposure, and the received light amount is determined by the selected photometric element. It is characterized in that the light emission of the strobe is stopped when it is detected and reaches a predetermined light receiving amount. As a result, the optimal light emission amount can be obtained for the in-focus subject.

For the START processing, the photometric switch SWS
Enter when is turned on. When this processing is entered, first, the distance measuring processing is performed on each of the distance measuring areas 33a to 33e, and the defocus amount is calculated for each of the distance measuring areas 33a to 33e (S101). Then, the predetermined distance measurement areas 33a to 33
The AF motor is activated based on the defocus amount for e, and the focusing processing is performed on the subject within the distance measurement areas 33a to 33e (S103).

Here, the predetermined distance measurement areas 33a to 33e are areas manually set by the photographer or areas automatically selected by the control means. Although the selecting means is not shown, in the manual setting, the photographer operates the setting means to select the distance measurement areas 33a to 33e. In the automatic setting,
There is known a configuration in which the control unit selects an area corresponding to the closest subject or a configuration in which the line of sight of the photographer is detected and set.

When the AF process is completed, the AE calculation process is executed (S105). FIG. 7 shows a subroutine of AE calculation processing. In this AE calculation process, subject brightness data is input from the divided photometric sensor 26, and photometric calculation is executed based on the brightness data to calculate the subject brightness (S201). Based on this subject brightness, ISO sensitivity Sv and exposure correction value Xv, strobe emission is assumed based on the exposure mode preset by the photographer, such as program, shutter priority, aperture priority, strobe program exposure mode, etc. The aperture value Av and the shutter speed Tv (exposure time) are calculated (S203). Furthermore, based on ISO sensitivity Sv and exposure correction value Xv, TT
The L_DA level is calculated and set (S205).

Then, the distance measuring areas 33a to 33e and the photometric sensors 41a to 41f are selected and the operation is returned (S207, S209). In this selection operation, if the distance measuring area has already been arbitrarily set, the set distance measuring area and the corresponding photometric sensor are selected, but in the case of automatic setting, the calculated distance measuring is performed again. Area 3
The defocus amounts of the respective 3a to 33e are compared, and the distance measuring area having the smallest defocus amount and the photometric sensor corresponding to the distance measuring area are selected and the process returns (S20).
7, S209). Since this processing is executed after the driving of the photographing lens in the AF processing of S103 described above, the focus state or the focus detection area closest to the focus state is selected at the current position of the photographing lens. Become.

Here, there occurs a case where one distance measuring area 33a to 33e cannot be selected. For example, when the defocus amount of all the distance measuring areas 33a to 33e or the plurality of distance measuring areas 33a to 33e is within a predetermined value, or when the defocus amount of all the distance measuring areas 33a to 33e is equal to or more than the predetermined value. There is. In this case, a selection signal for selecting the photometric sensor 41f for average photometry is output. The multiplexer 42 receiving the selection signal causes the distance measuring areas 33a to 33e to
The photometric sensors 41a to 41f corresponding to are selected.

When the above AE exposure calculation processing is completed, the above-mentioned processing is repeated until the release switch SWR is turned on (S109, S101 to S109). When the release switch SWR is turned on, the same distance measuring process as in S101 and the same AE process as in step S105 are executed to select the photometric sensors 41a to 41f to be used (S1).
11, S113). Here, the reason why the lens drive processing (AF processing) is not executed even if the distance measurement processing is executed is that the composition may be changed after the so-called focus lock is executed. Even in such a case, by performing the distance measuring process after the release switch SWR is turned on, it is possible to know in which distance measuring region 33a to 33e the main subject is located, and by executing the AE process, the main subject is located. Photometric sensor 4 corresponding to the distance measuring areas 33a to 33e
1a to 41e and 41f can be selected. S113 A
When the E calculation process is completed, the release process is executed, and when the release process is completed, the process returns to S101 (S115).

The details of the multipoint AF sensor defocus amount comparison processing in S207 will be described in more detail with reference to the subroutine shown in FIG. In the following description of the subroutine, CODE1 to 5 are photometric sensors 41a to 4a.
1e, and CODE 0 corresponds to the photometric sensor 41f.

This comparison process is performed by the photometric sensors 41a-41.
e, the defocus amounts of the distance measurement areas 33a to 33e corresponding to e are sequentially compared, and the smallest defocus amount is selected.
When the minimum defocus amount is less than a predetermined value, the photometric sensors 41a to 41e corresponding to the minimum defocus amount are selected, and when the minimum defocus amount is larger than the predetermined value, the photometric sensor 41f is selected.

When this subroutine is entered, it is first determined whether or not an effective defocus amount is obtained in all the distance measuring areas 33a to 33e (S301). If all are invalid, skip to S319, and if all are valid, S30.
7 (S301, S303). If there is an invalid defocus amount in part, the dummy defocus amount S is set to the invalid defocus amount, and the process proceeds to S307 (S301, S303, S305). The dummy defocus amount S has a larger value than a defocus amount D ′ described later.

In S307, CODE1 is set. Then, the defocus amount of the distance measuring area 33a corresponding to CODE1 is substituted into the variable D, and the variable n is set to 1 (S30).
9, S311). The variable n is a photometric sensor 41a-4.
1e, an integer from 1 to 5 corresponding to the distance measurement areas 33a to 33e.

1 is added to the variable n, and it is compared whether or not the defocus amount D is smaller than the defocus amount of the distance measuring area 33b (S313, S315). If it is not smaller, substitute the defocus amount into the variable D, set CODE2 and set S
Return to 307 (S317, S319, S321, S31
3). If it is smaller, it jumps S317 and S319 and returns to S313 (S315, S321, S307). The above comparison setting process is repeated for the defocus amounts of the five distance measuring areas 33a to 33e, and the smallest defocus amount and distance measuring area are selected.

When the processing for all the defocus amounts is completed, the defocus amount D is compared with a preset defocus amount D ', and if the defocus amount D is smaller, the process returns as it is, and if it is larger, CODE Is set to 0 and the process returns (S323, S325). The defocus amount D ′ is a predetermined allowable defocus amount, and when the defocus amount D exceeds the defocus amount D ′ within the allowable range, the desired subject is focused by the AF operation. This is the case when the composition is changed later and the subject is not in any of the distance measurement areas, and the subject other than the background or the main subject in front of the subject is in the distance measurement area. CODE0, that is, the photometric sensor 41f is selected.

TTL dimming is executed by using the photometric sensors 41a to 41f corresponding to CODEn corresponding to the shortest shooting distance selected by the above-described processing of S301 to S325.

Details of the release process are shown in FIG. When the release process is started, the mirror 21 is raised and the mirror 21
The diaphragm 11 that is narrowed down by a narrowing mechanism (not shown) that works in conjunction with the increase of the value is held at the set diaphragm value. Mirror 2
When 1 is completed, the front curtain of the shutter 27 is made to travel to start exposure and integration by the integration capacitor 44, and when the travel of the front curtain is completed, the strobe circuit 69 is provided with a strobe 5.
The light emission of No. 1 is started and waits until the integrated value of the reflected light of the subject by the photometric sensors 41a to 41f selected in S209 reaches the set value, that is, the output of the quench signal from the comparator 47 (S405, S40.
7, S409).

When the integrated value reaches the set value, the comparator 47
When a quench signal is output from, the flash circuit 69 is caused to stop emitting light and waits for the set exposure time to elapse (S407, S411, S413). When the set exposure time has elapsed, post-release processing, that is, the trailing curtain travels, the mirror 21 goes down, the film 28 winds up,
Processing such as mirror charging and shutter charging is executed and the process returns (S415). If the exposure time has elapsed before the quench signal is output, the strobe light emission is stopped, the strobe light emission is stopped, and post-release processing is executed (S407, S409, S411 to S415).

By the above processing, the TTL direct multi-point photometric sensor 41 corresponding to the in-focus subject is used for T
Since TL strobe light control is performed, stroboscopic photography with an appropriate exposure value is performed on the focused main subject. For example, as shown in FIG. 5A, the main subject 80 is located in the center of the photographing screen 29 and the areas 33c and 43 are formed.
When it overlaps with c, the focusing processing is executed on the distance measuring area 33c in which the main subject 80 enters, and the photometric area 43c
The photometric sensor 41c corresponding to c is selected, and the light amount of the strobe 51 is adjusted based on the reflected light from the main subject 80. Therefore, in this shooting, the main subject 80
Is focused, and the proper exposure value for the main subject 80 is obtained.

Moreover, in this embodiment, the photometric area 33c is sufficiently small with respect to the main subject 80, so that the photometric sensor 31c
Most of the subject light incident on is from the main subject 80. Therefore, the strobe light control is hardly affected by the background of the main subject 80.

Further, when the composition is changed as shown in FIG. 5B and the main subject 80 is arranged at the right end of the photographing screen 29, the focusing process is performed on the distance measuring area 33e in which the main subject 80 enters. Further, the TTL direct photometric sensor 41e corresponding to the photometric area 43e is selected. Therefore,
In this case as well, the main subject 80 can be focused and can be photographed with an appropriate exposure value.

Even when the focus is locked at the position shown in FIG. 5A and the composition is changed as shown in FIG. 5B, the main subject 80 is detected by the distance measurement process immediately before exposure.
A distance measuring area 33e in which is entered is detected, and this distance measuring area 33e is detected.
The photometric area 43e corresponding to, that is, the TTL direct photometric sensor 41e is selected. Therefore, also in this case, the main subject 80 can be photographed with an appropriate exposure value.

Although the above is the shooting in the automatic focus adjustment mode, the present invention can be applied to the shooting in the manual focus adjustment mode. In this case, the light metering sensors 41a to 41f corresponding to the distance measuring areas 33a to 33e having the smallest absolute value of the defocus amount are selected based on the distance measuring to the distance measuring areas 33a to 33e and the distance measuring result, and the strobe light control is performed. Do. Therefore, even in manual focusing, proper strobe light control is performed on the main subject in focus.

[0041]

As is apparent from the above description, the present invention is
A flash device, a multi-point distance measuring device, and a multi-point photometric device for independently measuring an area corresponding to the distance measuring area during exposure are provided, and each of the distance measuring areas is brought into a focused state or a focused state. Selects the photometric unit that measures the area corresponding to the closest distance measuring area, and when the flash unit emits light, it controls the stop of the flash unit's light emission based on the photometric result of that flash unit, so it is always in focus or in focus. It is possible to shoot with a proper exposure value for a main subject close to.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an embodiment of a single-lens reflex camera to which the present invention has been applied.

FIG. 2 is a block diagram showing an outline of a main circuit of the same-eye reflex camera.

FIG. 3 is a circuit diagram more specifically showing a dimming circuit of the same-eye reflex camera.

FIG. 4 is a multi-point ranging area and TTL of the same-eye reflex camera.
It is a figure explaining the relationship with a multipoint photometric area.

FIG. 5 is a diagram illustrating a relationship between a subject and a multi-point distance measuring area and a TTL multi-point photometric area in the same-eye reflex camera.

FIG. 6 is a diagram showing a main flowchart relating to a flash process of the present invention.

FIG. 7 is a diagram showing a subroutine regarding AE processing in the main flowchart.

FIG. 8 is a diagram showing a subroutine relating to a multipoint AF sensor defocus amount comparison process in the main flowchart.

FIG. 9 is a diagram showing a subroutine relating to release processing in the main flowchart.

[Explanation of symbols]

 10 Shooting Lens 20 Camera Body 21 Main Mirror 22 Sub Mirror 28 Film 39 Shooting Screen 31 AF Multipoint Distance Measuring Unit 33a to 33e Distance Measuring Area 41 TTL Direct Multipoint Photometric Sensors 41a to 41f Photometric Sensor 43a to 43f Photometric Area 51 Built-in Flash 61 CPU

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G03B 7/099 15/05

Claims (10)

[Claims] 1. A camera comprising a light emitting device for emitting a flashing means and a multipoint distance measuring device capable of measuring a plurality of distance measuring regions, each of which corresponds to each distance measuring region of the multipoint distance measuring device. Dimming metering means for metering an area; selecting means for selecting a dimming metering means corresponding to a focusing area or a ranging area closest to the focusing area, out of the ranging areas measured by the multipoint distance measuring device And a light control device for controlling the flash of the flash control means based on the light control metering means selected by the light control means selecting means. 2. The camera according to claim 1, further comprising a focus adjustment device, wherein the selection means makes the selection based on a distance measurement result obtained by the multi-point distance measurement device after focus adjustment by the focus adjustment device. A camera equipped with a light control device characterized by performing processing. 3. The camera according to claim 1, wherein the distance measuring process is performed by the multi-point distance measuring device after the release process is started and before the exposure is started, and the selecting means performs the light control based on the distance measuring result. A camera provided with a light control device characterized by selecting a photometric means. 4. The dimming light metering device according to claim 1, further comprising a light metering device for metering an entire area including all of the plurality of distance measuring areas. A camera equipped with a device. 5. The light control device according to claim 4, wherein when the distance measuring operation cannot be performed for all the distance measuring areas, a light measuring means for measuring the entire area is selected. camera. 6. The dimming control according to claim 1, wherein each photometry area of each of the photometry means has an area close to that of the corresponding distance measurement area. A camera equipped with a device. 7. Each of the light metering units according to claim 1 is a TTL multipoint light metering sensor that receives subject light reflected by a film and transmitted through a photographing lens of a camera. A camera equipped with a light control device characterized by. 8. The camera according to claim 1, further comprising a strobe built-in as a flash device, the camera having a dimming device. 9. A camera provided with a light control device according to claim 1, wherein the light control device adjusts the light intensity of a strobe device which is separate from the camera. 10. A camera comprising a light emitting device for emitting flashing light and a multi-point focus detection device capable of detecting the in-focus state of a plurality of focus detection regions, wherein each focus detection region of said multi-point focus detection device. A photometric metering unit for photometrically measuring an area corresponding to the selected area; a photometric metering unit corresponding to a focus detection area or a focus detection area closest to the focus status is selected from the focus detection areas detected by the multipoint focus detection device. A camera provided with a dimming device, comprising: a selecting device; and a dimming device for controlling the flash of the flash device based on the dimming photometric device selected by the photometric device selecting device.