JP2551853B2 - Flash tuning device - Google Patents

Description

The present invention relates to a flash tuning device for a camera shutter,
In particular, the present invention relates to a flash tuning device for controlling an appropriate aperture value for a predetermined time.

[Problems to be Solved by Conventional Techniques and Inventions] Conventionally, a flash tuning device has a program strobe AE corresponding to a program AE, aperture priority mode, etc. as an automatic exposure operation (hereinafter referred to as AE) for obtaining proper exposure. There is a priority strobe AE. Program AE automatically performs proper exposure using photometric values such as spot metering, average metering, and automatic backlight compensation.Program strobe AE enables a variety of flash photography for these proper exposures. ing.

Generally, for subject brightness, in aperture priority mode,
In a shutter mechanism having a shutter blade that also serves as a diaphragm for controlling a predetermined diaphragm by restricting the diaphragm in the middle of the opening movement, an abnormal diaphragm aperture due to an excessive phenomenon occurs. In Japanese Patent Application No. 61-81512, an exposure device for an autofocus camera is provided with various means so as to cover the farthest subject and the latest subject, which are related to the effective use of the aperture priority mode. As described above, the exposure control for the subject luminance plane is almost programmed in order to obtain the required photographing effect. However, by setting the aperture value in aperture priority mode,
A kind of limitation is added to the programmed exposure control, which has a great influence not only on the exposure control but also on the flash tuning, and there is a drawback that effective flash tuning cannot be obtained if transient phenomena are ignored.

[Object of the Invention] The present invention has been made in view of the above-mentioned point, and in the aperture priority mode, the generation time of the flash signal synchronized with the flash tuning means is set to a predetermined time after the shutter that also serves as the aperture reaches the set aperture value. An object of the present invention is to provide a flash tuning device that can obtain dimming suitable for shooting conditions by setting a time point different from the program AE that generates a flash signal in the lens shutter opening.

Also, suitable for subjects at different distances by providing aperture setting means for setting aperture values capable of capturing images of subjects at different distances, and setting the time point of generation of the flash signal to a predetermined time after the shutter reaches the set aperture value. It is an object of the present invention to provide a flash tuning device that can obtain the dimming.

[Means for Solving the Problems] A flash tuning device according to the present invention is a flash tuning device provided with a lens shutter that also operates as an aperture in a program AE mode and an aperture priority mode. In the aperture priority mode, the shutter has a set aperture. A flash synchronizing signal generating means for generating a flash signal when the diaphragm operation is stable after a predetermined time after reaching the value, and a flash signal for shutter opening during the lens shutter opening in the program AE mode, the program AE mode and the diaphragm. It is composed of a mode selecting means for selecting one of the priority modes, and a flash tuning means for flashing in synchronization with the flash signal when the diaphragm operation is stable or the flash signal when the shutter is open according to the mode selected by the mode selecting means. .

Further, the aperture priority mode is composed of aperture setting means for setting aperture values capable of imaging subjects at different distances.

[Embodiment] An embodiment of the flash tuning apparatus according to the present invention will be described in detail below with reference to FIG.

In FIG. 1, reference numeral 1 is a distance measuring circuit. The distance measuring circuit 1
The modulated irradiation spot f ₁ under the control of the CPU 14 is the subject S.
It irradiates UB and synchronously detects the reflection spot f ₂ reflected from the subject SUB. Distance data LD generated by synchronous detection
Is sent to the CPU 14 and the depth of focus calculation circuit 2. The focal depth calculation circuit 2 calculates the depth of focus from the distance data LD input from the distance measurement circuit 1 and the lens F number set by the lens F number setting device 3, and the switching data device Dn (n = 1 is a backlight data device, n = 2 the brightness data unit, n = 3 is darkness data unit, n = 4 is shallow depth of focus unit, n = 5 among deep focal depth instrument), the outlet side of the D ₄ or D ₅ to H level To do. Switching data device
Dn operates when the signal input by the comparator composed of the differential amplifier or the window comparator is within a certain standard or range. The comparator criteria or window range is specified by the CPU 14.

The photometric circuit 4 receives the image signal f ₃ of the subject SUB and sends the brightness data BV to the exposure condition calculation circuit 5. This brightness data BV is obtained by measuring the photometric values of the center, left and right, and the periphery separately, and the exposure condition calculation circuit 5 inputs the brightness data BV.
And the brightness data BV according to ISO set by the film speed setting device 6 are divided into backlight, brightness, and darkness, and switching data devices D ₁ , D
₂ , send to D ₃ . The switching data units D ₁ , D ₂ and D ₃ set the outputs of the switching data units D ₁ , D ₂ and D ₃ to H level when there is backlight, brightness and darkness in the range designated by the CPU 14. The exposure condition calculation circuit 5 sends the calculated analog signal to the A / D conversion circuit 12.

The CPU 14 indexes the step motor control data MD of the ROM 16 according to the exposure data output from the A / D conversion circuit 12 and the aperture value input from the aperture value bus BUS, and sends the indexed control data to the motor control IC 17 To do. Since the CPU 14 receives the distance data LD from the distance measuring circuit 1 as described above, it sends the focus signal FOU to the motor control IC by the first step operation of the release button (not shown). Since the motor control IC 17 sends a pulse to the motor 19 via the motor drive circuit 18, the lens 21 is extended to the in-focus position by the rotation of the rotor 19a.

When the release button is pushed to the second stage operation, the shutter blades 20a, 20b which also serve as apertures operate according to a predetermined program.
At this time, the number of forward / reverse rotation pulses of the motor 19, the pulse width, and the brake pulse are determined by the indexed step motor control data MD.

Since the CPU 14 receives the setting of the program AE mode MOD1 or the aperture priority mode MOD2 via the mode setting circuit 15, either the normal flash data ND or the delay flash data DD provided in the ROM 16 via the aperture expansion unit 13 is used. The pulse generation time of the normal flash pulse generation circuit 8 or the delay flash pulse generation circuit 9 is determined.

The switching unit 7 is a circuit for performing a logical calculation according to the switching data from the switching data unit Dn and activates the normal flash pulse generating circuit 8 or the delay flash pulse generating circuit 9 by the logical calculation.

The logical operation of the switching unit 7 is shown below. If the symbols D ₁ , D ₂ ... Are H level, the switching to the normal flash pulse generation circuit 8 is NF, and the conversion to the delay flash pulse generation circuit 9 is DF, the backlight D ₁ is NF, the brightness D ₂ + shallow. Focus D ₄ is NF,
Lightness D ₂ + deep focus D ₅ is DF, darkness D ₃ + shallow focus D ₄ is NF,
DF logical calculation is performed on the darkness D ₃ + deep focus D ₅ .

Next, when the distance measuring circuit 1 measures distances to subjects at different distances, the depth calculation circuit 2 is the farthest from the aperture expansion unit 13 regardless of the setting of the mode setting circuit 15, and the depth of focus at which the subject can be recently captured is set. Output. In the aperture expansion unit 13, the delay flash data DD of the ROM 16 corresponding to the input depth of focus
Be prepared to index the aperture value of.

As shown in FIG. 2, the normal flash data ND and the delay flash data DD are delay data DTn (n is 0) from the time when the shutter blades 20a and 20b start operating the diaphragm to the time when a predetermined time has elapsed after reaching the set diaphragm value. To 256) and the return data RTn at which the shutter blades 20a and 20b start closing, the aperture value bus memory BUS (uses the same name as the aperture value bus BUS) and the exposure data memory EVD.
To prepare.

Bits 0 to 10 of the aperture value bus memory BUS have idle flags IDF ₀ to ₁₀ and are usually all set to "1" according to the aperture priority mode MOD2 or the depth of focus calculated by the depth of focus calculation circuit 2. The flag becomes "0". The address table ADT at the position where the flag is "0" is to be indexed. The address table ADT is composed of 11 words of 0 to 10, and the address adr of DDn is written in 0 to 19 bits of each. 0 word is DD1, 1 word is DD1.4 ... 10 words is DD32 (numerical value corresponds to aperture value), and the delay flash data table DDΔΔ of the same name is indexed. DDΔΔ has a structure of 0 to 256 words, 0 to 11 are filled with delay data DTn, and 12 to 23 bits are written with return data DRn.

For normal flash data DD, DDΔΔ
Is NDΔΔ, the delay data DTn is normal data NTn, and the return data DRn is NRn.

Exposure data memory EVD has index data TLR (0 to 256)
Is input via the exposure condition calculation circuit 5 and the A / D conversion circuit 12, and the corresponding DTn, DRn or NTn, NRn is indexed.

[Operation of the Invention] In the flash tuning device having the above-described structure, as shown in FIG. 3, the normal data NTn and the return data NRn are the index data TLR.
(0 to 256) in the are indexed shutter blade 20a from P ₁ point to P ₃ points, 20b are flashing signal when the shutter opening over P ₂ point in the opening is sent to the flash tuning circuit 10. Will set the aperture value at P ₃ points, the shutter blade 20 in a path to P ₄ points from P ₃ points
a and 20b are closed.

As shown in FIG. 4, when the delay data DTn and the return data DRn are indexed by the index data TLR (0 to 256), P
Shutter from _five points in time to reach the P ₆ points reaches the set aperture value, operation stability during the flash signal stop the delay data DTn have elapsed P ₇ points from P ₅ points are sent to the flash tuning circuit 10, P ₅ points shutter blades 20a in route to P ₉ points from P ₈ points defined by the return data DRn of P ₈ points, 20b is closed from.

That is, _six points P, the shutter blades 20a to set the aperture value, the 20b is regulated, the shutter opening diameter by transients as FIG. 4 continues unstable state. If a flash signal is sent during this period, flash photography with many errors will occur, which is not preferable.

Therefore, taking the elapsed time until P ₇ points, opening diameter so as to deliver the flash signal after stable.

When the aperture 11 is set in the aperture priority mode MOD2, the idle flag IDF of the aperture value bus memory BUS shown in FIG.
It becomes 111011 ". Therefore, in the delay flash data table DDΔΔ, DD11 is an index target table, and the index data TLR (0 to 256), for example, between EV values 9 and 10 is stored in the exposure data memory EVD from the photometry circuit 4 via the A / D conversion circuit 12. /Four
Since about 12 pieces of delay data DTn and return data DRn are entered between the second and the 1/8 second, the flash tuning circuit 10 can operate with an accuracy of the unit of about 10 μS.

When the distance measuring circuit 1 approaches the subject, the idle flag IDF of the aperture value bus memory BUS becomes, for example, "1100111111". In this case, delay flash data table DD
For ΔΔ, DD2 and DD2.8 are indexed to determine the delay data DTn and the return data DRn.

[Effects of the Invention] As is apparent from the above embodiments, the flash tuning device according to the present invention is a flash tuning device provided with a lens shutter that also operates as an aperture in the program AE mode and aperture priority mode. A flash synchronization signal generating means for generating a flash signal at the time of stable operation of the diaphragm after a predetermined time after the shutter reaches the set aperture value, and for generating a flash signal at the shutter opening in the lens shutter opening in the program AE mode; A mode selecting means for selecting one of the program AE mode and the aperture priority mode, and a flash for flashing in synchronization with the aperture operation stable flash signal or the shutter opening flash signal according to the mode selected by the mode selecting means. Since it is composed of the tuning means, there is an effect that the tuning suitable for the photographing condition can be obtained.

Further, since the aperture priority mode is composed of aperture setting means for setting aperture values at which subjects at different distances can be imaged, proper synchronization is achieved even when a depth effect is obtained for subjects at different distances. There is an effect to be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a flash tuning device according to the present invention, FIG. 2 is a data configuration diagram relating to FIG. 1, and FIG.
FIG. 4 and FIG. 4 are characteristic diagrams of dimming according to FIG. 7 ... Switching unit (mode selection means) 8 ... Normal flash pulse generation circuit (flash synchronization signal generation means) 9 ... Delay flash pulse generation circuit (flash synchronization signal generation means) 2 ... Depth of focus calculation circuit (aperture setting) Means) 13 …… Aperture expansion unit (Aperture setting means) MD …… Motor drive data

Claims (2)

(57) [Claims] 1. A flash tuning apparatus having a lens shutter that also functions as an aperture, which operates in a program AE mode and an aperture priority mode, and when the aperture operation is stable after a predetermined time after the shutter reaches a set aperture value in the aperture priority mode. Flash light synchronization signal generation means for generating a flash light signal and for generating a flash light signal during shutter opening in the lens shutter opening in the program AE mode; and mode selection means for selecting one of the program AE mode and aperture priority mode. And a flash tuning means for flashing in synchronization with the flash signal when the diaphragm operation is stable or the flash signal when the shutter is open, according to the mode selected by the mode selecting means. 2. The flash tuning device according to claim 1, wherein the aperture priority mode is a mode which is operated by aperture setting means for setting aperture values capable of photographing subjects at different distances.