JPH03123326A - Photometry device for camera - Google Patents

Abstract

PURPOSE:To prevent a photograph from being underexposed even in the case that there is some time up to the releasing time from the measuring time by executing the photometry of an object again when a releasing switch is operated after a switch for range-finding is turned on or before the exposure of photographing by a self-timer is executed. CONSTITUTION:Information concerned with the brightness of the object is inputted to a controller 2 including a CPU from a photometry circuit 22. Based on the information, a shutter in a shutter circuit 24 is controlled at the time of releasing. Then, at the time of photographing, it is executed based on a range-finding action by an autofocusing device (AF) 28 and a photometric action by the photometry circuit 22. At this time, when the switch for range-finding 10 is operated, the range-finding and the photometry of the brightness of the object are executed. When the releasing switch 8 is operated next, the photometry of the brightness of the object is executed again. The exposure is executed based on the photometry data by the re-photometry and the photographing is finished. In the case of the photographing by the self-timer, as well, it is executed based on the photometry data by the re-photometry just before the release.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a camera photometry device that measures subject brightness for an automatic exposure device as close as possible to the time of release.

[Conventional technology]

In order to simplify photography, cameras with automatic exposure devices have become popular, allowing the camera itself to determine the exposure and automatically emitting a strobe when the brightness of the subject is insufficient. This camera with an automatic exposure device measures the brightness of a subject, determines the shutter speed and aperture according to the brightness, and performs exposure. Furthermore, in addition to automatic exposure devices, cameras have become widespread that are equipped with so-called autofocus devices that automatically measure the distance to a subject, thereby eliminating the need for focusing, making photography even easier.

Photometry of subject brightness by a conventional photometer of this type is performed when the distance to a subject is measured by the autofocus device. For example, the release button that is pressed to release the camera is a two-stage switch, and when pressed halfway, distance measurement and photometry are performed, and when the button is pressed all the way, the release is performed.

[Problem that the invention seeks to solve]

However, at the time of release, exposure is performed based on distance measurement data and photometry data obtained when the release button is pressed halfway, resulting in the following problem.

Unless the subject is a moving object, the distance to the subject does not change between distance measurement and shutter release. However, the distance measurement data will not be inconvenient. Therefore, the photo will not be out of focus.

However, even if the subject is stationary, the photometric data may change. That is, in cases where the wind is strong and the clouds are moving quickly, the sun may be hidden behind the clouds when the camera is released even if the sun is out at the time of photometry. Therefore, there is a risk that the photograph will be underexposed.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a photometry device for a camera that prevents photographs from being underexposed as much as possible even when there is a time interval between photometry and release.

[Means for solving problems]

In order to achieve the above object, the camera photometry device according to the present invention includes an automatic exposure device that measures the brightness of the subject and uniquely determines the shutter speed and aperture, and an automatic exposure device that measures the subject distance and adjusts the shooting lens. In the photometering device of a camera, which is equipped with an autofocus device for focusing and performs a distance measurement operation and a photometering operation by operating a distance measurement switch for causing the autofocus device to perform a distance measurement operation at the time of shooting, the above-mentioned If the release switch is operated after the distance measurement switch is operated, or if the self-timer shooting switch is operated to take a self-shot, light metering is performed again before exposure and the new metering data is updated. It is characterized in that exposure is performed based on.

[For production]

When the distance measurement switch is operated, the distance to the subject is measured and the subject brightness is measured6.Then, when the release switch is operated, the subject brightness is measured again and then the shutter is released, and the above distance measurement is performed. Exposure is performed based on the data and the photometry data obtained by re-metering, and the photographing ends.

Also, when the self-timer switch is operated, the self-timer is activated and distance measurement and photometry are not performed, and when the timer ends, photometry is performed again.

Photographing is performed based on the distance measurement data and the photometry data obtained by re-photometry.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The photometric device according to the present invention will be specifically described below based on the illustrated preferred embodiments.

FIG. 1 is a block diagram of this photometric device, which is mainly composed of a controller 2 including a CPU. This controller 2 includes a main switch 6, a release switch 8, a focus lock switch 10 as a distance measurement switch, and a switch unit 4 for external input. A selfie switch 12 for performing self-photography using a self-timer, a long-distance switch 14 for performing distant view photography, and a mode switch 1 for switching shooting modes.
6.Other ON-OFF switches such as a switch for switching the photographing lens between standard photography and telephoto photography and a switch for rewinding the film are input. Information regarding film sensitivity is input from the DX section 18 to the controller 2 as a DX code. When the film is wound and fed by one frame, a signal to that effect is input to the controller 2 from the 80 copy 20.

Information regarding the subject brightness measured by the photometry circuit 22 is input to the controller 2, and information regarding shutter control at the time of release is exchanged between the controller 2 and the shutter circuit 24 based on the brightness information.

Further, depending on the brightness information, flash photography may be performed, and therefore information regarding the charging state of the strobe and light emission is exchanged between the controller 2 and the strobe circuit 26.

Furthermore, information regarding subject distance and information regarding focusing are exchanged between the autofocus device (AF) 28 and the controller 2, and when the focusing state is appropriate, the AP
If the LED 3G lights up or is inappropriate, the AP
LED 30 blinks. Further, if the focus state is inappropriate, a signal to that effect is sent from the controller 2 to the buzzer 32, and the buzzer 32 sounds.

A motor drive signal from the controller 2 is sent to the zoom feed motor driver 34, and based on the signal, the photographic lens drive motor 34a or the film feed motor 3 is
4b is driven to move the photographic lens forward and backward in the optical axis direction to change the focal length, or to wind or rewind the film.

The controller 2 also includes a liquid crystal display device (LCD).
36 is connected, and the LCD 36 displays information regarding the number of remaining films, strobe photography, self-photography, remaining battery power, and the like.

Furthermore, when performing self-photography, the self-LEDa8 is turned on in response to a signal sent from the controller 2 to that effect.

Figures 2 to 4 show a camera 4 equipped with this photometric device.
0. This shows the general appearance of 0. The second @ is a front view, in which a photographic lens 42 is arranged in the center of the dome, a finder 44 is provided above the photographic lens 42, and a side of this finder 44 and a side of the photographic lens 42 are respectively arranged. Light emitting section 28a and light receiving section 28b of autofocus device 28
and are provided. Further, a light emitting window 26a of the strobe circuit 26 is provided on the side of the light emitting portion 28a.

The third @ is a plan view of the camera 40, in which a release switch 8 is disposed at the upper left side when facing the photographing lens 42, and the camera is released by pushing the release switch 8.

Further, FIG. 4 is a rear view of the camera 4o, and a main switch 6 which also serves as an opening/closing switch for a barrier for protecting the photographic lens 42 is arranged on the side of the viewfinder 44.
Furthermore, a focus lock switch 1G is provided on the side of the main switch 6.

Note that the back cover 46 for loading and unloading the film is opened by operating the back cover opening/closing lever 48.

Next, the photometry procedure of this photometry device will be explained together with the exposure operation of the camera 40 based on the flowcharts related to shutter control shown in FIGS. 5 to 8.

When the main switch 6 is turned on and the barrier is opened, the camera 40 can be used for photographing, and the controller 2 cancels unnecessary information and enters a standby state. In this state, the focus lock switch 10
When is turned on, shutter control is performed (step SOO).

First, it is determined whether or not the first self flag (described later) is set (step 501). If not, it is determined whether the release switch 8 is turned on by determining whether or not the SP flag is set. to judge. (Step 502), if this judgment is No, the distant view switch 14 is operated and the 5INF
Step 5: Determine whether the flag is set or not.
03), if the SP flag is set, determine whether the SP flag is set (step 504); if the SP flag is not set, return to step 503 and repeat the determinations in step 503 and step 504. Become.

If the 5INF flag is not set in step 503, the 5INF change flag is reset in step 505, and it is determined whether the focus lock flag (SPFL flag) is set (step 506).
If the FL flag is not set, the process proceeds to strobe control to be described later (step aOa).

If the SP flag is set in step 504 above, after resetting the SP change flag (step 5
07) Set the shutter BC flag (step 5)
08), and if the 5PFL flag is set in step 506, the 5PFL change flag is reset (step 508), and then the shutter BG flag is set (step 509), and the SP is set in step 502. If the flag is set, the process advances to step 507.

Next, in the BC (battery check) subroutine, a shutter control system battery check regarding release is executed (step 510).

Reset the shutter BG flag (step 511
). In step 512 following step 511, DX processing is performed based on the film sensitivity obtained from the DX code, and then lens determination processing is performed (step 513). Furthermore, if the first self flag is set in step 501 above, approximately 10 m5
The process waits until the time period elapses (step 514), and then proceeds to step 512.

After executing the lens determination process (step 513), it is determined whether one or both of the 5ELFI flag and the 5ELF2 flag, which will be described later, are set (steps 515 and 516), and if neither is set, , photometry is performed by the photometry circuit 22 (step 517), and AE calculation for determining exposure is performed based on the obtained photometry data (step 518).
In addition, if either the 5ELFI flag or the 5ELF2 flag is set as determined in step 515 or step 516, step 5
Proceeding to step 19, it is determined whether the first self flag is set, and if it is not set, the process proceeds to step 517.
If it has been set, the process advances to step 716, which will be described later.

After performing the AE calculation (step 518), step 6
The process advances to step 01 to determine whether the INF flag for distant view photography is set. If the INF flag is not set, it is determined whether to set the AAE flag for re-photometry (step 602), and if the A or AE flag is not set, AF sub-control for autofocus is performed (step 602). Step 603), that is, by turning on the focus lock switch 1°, subject brightness is measured (step 517), AE calculation (step 518) is performed, AF sub-control is performed (step 6o3), and the subject distance is is measured.

Next, strobe processing is performed (step 604).
), it is determined whether or not the strobe uncharged flag is set by the strobe processing (step 605); if it is not set, the strobe light emission flag for determining whether or not to perform strobe photography is determined based on the result of the AE calculation (step 518). It is determined whether the strobe light emission flag is set (step 606). If the strobe light emission flag is set, the process proceeds to step 607 to perform FM (flashmatic) processing, and it is again determined whether the AAE flag is set (step 608).

If the INF flag is set in step 601, an INF process is performed to focus the photographing lens to infinity and stop the strobe light emission for distant scenery photography (step 609), and then the process proceeds to step 608. Also,
If the strobe light emission flag is not set in step 606, there is no need to perform FM processing, so proceed to step 608. Also, if the AAE flag is set in step 602, AF sub-control step 6o3 ) without performing strobe processing (step 604
).

Furthermore, if the strobe uncharged flag is set in step 605, it means that it is not possible to take a picture with proper exposure, so the process proceeds to step 803, which will be described later.

If the AAE flag is not set in step 608, the process proceeds to step 610 to determine whether the SP flag is set. If the AAE flag is set, the process advances to step 704, which will be described later.

If the SP flag is not set in step 610, the process proceeds to step 611, where AFLED & BZ processing is performed to determine whether to light up or blink the APLED 30, or to sound the buzzer 32 if necessary. Determine the set (step 6)
12), 5 if the SP flag is not set.
It is determined whether or not the setting of PFL is continued (step 613), and if it is set, step 61
1 and repeats the determination at step 612. That is, the CPU waits for the SP flag to be set, that is, for the release switch 8 to be turned on. Then, the release switch 8 is turned on and in step 612
If the P flag is set, after resetting the sP change flag (step 614), a PL flag (to be described later) is set (step 615), and the process proceeds to step 616, where it is determined whether the 5HEND flag is set.

If the SP flag is set in step 610, the process advances to step 616. Furthermore, if the 5PFL flag is not set in step 613, this means that the focus lock switch has been turned off, that is, photography is stopped.
Step 617) to reset the 5PFL change flag;
After setting the 5HEND flag (step 618), the process proceeds to step 616, and from step 616 the process proceeds to step 803, which will be described later.
If the END flag has not been set, the process proceeds to step 701 because photographing will continue.

In step 701 and step 702, 5
It is determined whether the ELFI flag and the 5ELF2 flag are set, and if neither flag is set, it is determined whether the FL flag is set (step 70
3) This FL flag is set in step 615 when the release switch 8 is turned on and the SP flag is set (step 612) in the state of waiting for the SP flag, so the FL flag is set in step 703. is set. For this reason, step 7
After proceeding to step 20 and setting the AAE flag for re-photometry, the process returns to step 517 to perform re-photometry and AE calculation (step 518) based on the new photometry data. That is, when the focus lock switch 10 is turned on and the camera waits for the SP flag to be set (step 612), photometry is performed again after the release switch 8 is turned on. And step 51
From step 8, the process proceeds to step 601 and step 602. Since the AAE flag is set to 1 in step 602, the process proceeds to step 6G14. That is, AF control (step 603) is not performed when photometry is re-measured. This is because the subject distance does not change even if the subject brightness changes. And step 60
Proceed from step 8 to step 704 and turn on the step motor.
Then, the photographing lens 42 is moved to the in-focus position based on the distance measurement data. After that, wait for 10 meters to elapse (step 705), and then check the shutter (SHTCHK).
) (step 706), exposure (EXP) is performed (step 707), and step 707
Now, output the trigger to make the strobe 26 fire if necessary (FT), output the exposure time (0), then:
Turn on the self LED 38 (step 708),
The PLE D3G is turned on (step 709), and the photographing lens 42 is returned to the reference position (step 71).
0), then turn off the self-LED 38 in step 7.
11), Turn off the APLED3G step 712),
The number of AF stages is output based on the output of the encoder for detecting the position of the photographic lens 42 (step 713), a shutter check is performed (step 714), and an OE flag indicating the end of photographing is set (step 715).
).

After setting the OE flag (step 715), 5
Step 801: Determine whether one or both of the ELFI flag or the 5ELF2 flag is set.
．． Step 802), if neither flag is set, reset the FL flag (step 802).
03), and then determines whether the oE flag is set (step 804). If it is set, that is, if shooting has ended (step 715), the process advances to step 805 and the MR is used to advance one frame or manually rewind. ) is performed, and the unshot film is wound or rewound for the next shooting, and if the OE flag is not set in step 804,
Since photographing has not yet been completed, the process proceeds to step 808, where strobe control is performed and then standby is made in preparation for the first photographing (step 809).

Next, the procedure when the 5ELFI flag and the 5ELF2 flag are set will be explained.

These 5ELFI flag and 5ELF2 flag are set when performing self-photography using the self-timer, and are changed as shown in FIG. 9 by operating the self-timer switch 12 and mode switch 16.

In other words, this camera can perform so-called multi-self photography, and as shown in column 1 91, column 2 92, column 3 93, and column 441194 in FIG. In this case, you can take a selfie up to three times in a row. And in the case of 3 shots (4a94): C, 5ELF17-F
If both the flag and the 5ELF2 flag are set, and there are two shots (3rd ([93)), the 5ELF27 flag is set, and if there is one shot (2aI92)
, only the 5ELFI flag is set, and in the case of normal shooting (11i91), which is not self shooting
Neither the 1 flag nor the 5ELF2 flag is set. Note that, as shown in FIG. 9, the liquid crystal display device 36 displays a display corresponding to each shot number.

The case where 3 shots is selected will be explained.

If 3 shots are selected, the fourth column 94 in FIG.
As shown in FIG. 2, since both the 5ELFI flag and the 5ELF2 flag are set, and the 5ELF1 flag is set, a YES determination is made in step 515, and the process proceeds to step 519, where it is determined whether the first flag is set.

At this time, the first flag is not set, so
Proceeding to step 517, the above-described procedure is executed to reach step 701. Since the 5ELFI flag is set here, the process proceeds to step 716, and an interrupt (TI ME I
NT), waits for the elapse of a predetermined time, and executes self-processing in preparation for self-photography such as releasing the camera (step 717). Next, the interrupt for counting of the self-timer is stopped (step 718), and it is determined whether the self-cancellation flag is set (step 719). If the self-cancellation flag is set, shooting is stopped. Therefore, the process proceeds to step 803, resets the FL flag, and then performs strobe control (step 808). If the self-cancellation flag is not set, then the process proceeds to step 720, where the AAE flag is set, since photography is to be continued, and the process proceeds to step 517, where re-metering is performed and AE calculation is performed based on the photometry data. (step 518), and step 6
08, proceed to step 704, and then proceed to step 715.
Filming will take place up to. Then, the process proceeds from step 801 to step 810, where the first flag is set. Since the OE flag is set (step 715), steps 804 to 805
After proceeding to 1 frame advance or MR processing, 5
The ELF1 flag and 5ELF2 flag are reset (step 806).

In step 806, the 5ELFI flag, 5EL
The state of the F2 flag is determined, and if it is at No. 4 [94 in FIG.
will return to. In addition, S E L F1 flag, 5
If the ELF2 flag is in the third column 93 of FIG.
It will be shifted to 91 sequentially.

In this case, since the first self flag is set in step 501 (step 810), the process advances to step 514, waits for 10 絽 to pass, and then steps 5
Go forward 12. Then, in step 516, 5ELF2
Since the flag is set, proceed to step 519,
Since the first selfie flag is set, proceed to step 716 and set TIME INT for selfie photography.
Start. In step 717, self-processing is performed, and the length of the self-timer is changed depending on the states of the 5ELFI flag and 5ELF2 flag. For example, in the case of the first shot, the timer is set to 10 seconds, and from the next shot onwards, the timer is set to 3 seconds. Then stop TIME INT (step 718).
, after setting the AAE flag (step 720), photometry is performed again (step 517), and the process proceeds from step 608 to step 704, and the following step 7
The photographing of the second shot is completed by the steps up to step 15. When the process proceeds to step 802, the 5ELF2 flag is set, so the first self flag is set in step 810, and then from step 804 to step 8.
In this step 806, which proceeds to step 06, the states of the 5ELFI flag and the 5ELF2 flag are shifted from 3a93 to 2a192 in FIG. 9 as described above. Then, after performing strobe control (step 807), the process returns to step 501 and the above-mentioned procedure is repeated to finish photographing the third shot. In step 806, the 5ELFI flag and 5ELF2 flag are reset, and the strobe control (step 807) is performed.
Step 807) is performed to standby. 1. Although not shown in the figure, once the shooting during normal shooting or the final shot during multi-self shooting is completed, adjustment flag reset processing is executed to reset the first self flag and OE flag, and the next shooting is started. You will be prepared.

In this embodiment, the focus lock switch 10 as a distance measurement switch is provided separately from the release switch 8, but the release switch 8 can be made into a two-stage switch and also serve as the focus lock switch, as in the conventional case. Alternatively, a two-stage release switch that also serves as a focus lock switch may be further provided with a dedicated focus lock switch 10.

〔Effect of the invention〕

As explained above, according to the camera photometry device according to the present invention, when the release switch is operated after the distance measurement switch is turned on and the focus is locked, the light is measured again before the release. . Therefore, exposure can be performed based on the brightness of the subject immediately before the release, and even when photographing in a situation where the weather changes drastically, underexposure or overexposure can be prevented as much as possible. In particular, when taking pictures using the self-timer, a certain amount of time is required from the time the self-timer starts counting until the release is released, so it is important to measure the exposure just before the release to ensure the correct exposure. can.

[Brief explanation of drawings]

The drawings show a preferred embodiment of the photometric device according to the present invention, and FIG. 1 is a block diagram of this photometric device. FIG. 2 is a front view of the camera, FIG. 3 is a plan view, and FIG. 4 is a rear view. FIGS. 5 to 8 are flowcharts relating to shutter control for explaining the procedure of this photometric device. FIG. 9 is for explaining the state of change of the flag when performing multi-self-photography in which self-photography can be taken multiple times in succession. 2... Controller 6... Main switch 8
...Release switch 10...Focus lock switch (distance measurement switch) 12...Self switch 14...Landscape switch 16...Mode switch 22...Photometering circuit 24...Shutter circuit 26 ... Strobe circuit 28 ... Auto focus device (AF) 30 ... A
F L E D 38...Self-LED patent issuer Fuji Photo Light Co., Ltd.

Claims (1)

[Claims] It is equipped with an automatic exposure device that meters the subject brightness and uniquely determines the shutter speed and aperture, and an autofocus device that measures the subject distance and focuses the photographic lens. In a camera photometer that performs distance measurement and photometry by operating a distance measurement switch, when the release switch is operated after the distance measurement switch is operated, or A photometering device for a camera, characterized in that when a self-timer photography switch is operated to take a selfie, photometry is performed again before exposure, and exposure is performed based on the new photometry data. .