JP2525349B2 - Flash device for camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a camera having a sector shutter, and causes the flash light emitter to emit light with a guide number of the flash light emitter and an appropriate exposure aperture value determined according to a shooting distance. Regarding flashmatic devices.

(Prior Art) As a flashmatic device in a camera having a sector shutter whose opening amount gradually increases from a closed position, there is a device as disclosed in Japanese Utility Model Publication No. Sho 57-22167. This device has a sub diaphragm that is mechanically connected to the shutter to operate, and a photodetector that detects the aperture value of the sub diaphragm by a change in the amount of light obtained through the sub diaphragm.
The distance information signal obtained from the focus adjustment ring is compared with the aperture value so that the flash light emitter emits light at an appropriate aperture value.

(Problems to be Solved by the Invention) However, the above-mentioned device requires a new sub-diaphragm device, which causes a problem that the device becomes large.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a flashmatic device for a camera that does not use a sub-aperture device that increases the size of the device.

(Means for Solving Problems) A configuration of the present invention for achieving the above object will be described with reference to FIG. The camera body is provided with a sector shutter 1 whose opening value gradually increases from the closed position in conjunction with the release operation. In order to detect the opening amount of the sector shutter, the moving position of each part of the sector shutter or a member mechanically interlocked with the sector shutter at each moment during movement is detected and output as a sector opening corresponding value. An opening amount detecting means 2 is provided. In order to control the exposure by the sector shutter 1, when a proper exposure amount is obtained based on the output of the aperture amount detection means 2, the subject luminance information and the film sensitivity information, a closing signal for closing the sector shutter is output. The exposure control calculation means 3 is provided.

Further, there is provided a flashmatic calculating means 4 for calculating an aperture value at which the flash photographing is performed with an appropriate exposure based on the film sensitivity information, the photographing distance information and the guide number information of the flash light emitting device. There is provided flashmatic discriminating means 5 for comparing the calculated value of 4 with the opening amount corresponding value obtained from the opening amount detecting means 2 and outputting a trigger signal when the two coincide. The output of the flashmatic discriminating means 5 is connected to the flash light emission trigger means for receiving the trigger signal and causing the flash light emitter to emit light.

(Operation) The operation of the present invention configured as described above will be described.

When the sector shutter 1 starts opening in conjunction with the release operation, the opening amount detecting means 2 detects the opening amount. Based on the detected opening amount, the film sensitivity information, and the subject brightness information, the exposure control calculation means 3 outputs a closing signal to the sector shutter 1 so that proper exposure can be obtained. Further, the aperture calculation value calculated by the flashmatic calculation means 4 for obtaining the proper exposure at the time of flash photography and the aperture value of the sector shutter 1 detected by the aperture amount detection means 2 are compared, and both are coincident. At this time, a trigger signal is output to the flash light emission trigger means to cause the flash light emitter to emit light.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS.

First, the drive unit of the sector shutter 1 is, as shown in FIG. 2, an output gear fixed to the output shaft of the reversible drive motor 11.
12 drives the drive gear 14 via the intermediate gear 13 and the motor 11
It is designed to rotate in the same direction as. This drive gear
A conductive pattern 15 to be described later is provided on the front surface of 14, and a cam groove 14a into which a cam engaging pin 17b is fitted is provided on the back surface. Cam groove 14 provided on the back surface of this drive gear 14
The radius of a is changed from the center point O. That is, the cam groove 14a has a groove width slightly larger than the diameter of the cam engaging pin 17b, and the end portion 1
4d has the smallest radius and the largest radius of the end 14c. Between the end portions 14c and 14d, the cam groove 14a is formed so that the radius from the center point O gradually increases.
Are formed.

On the other hand, the conductive pattern 15 has a pattern formed by repeating a plurality of strip-shaped conductive portions and insulating portions from the substantially central portion in the radial direction of the driving gear 14 to the outer peripheral direction, and the end portion 14
It is provided on the corresponding outer peripheral side between c and the end portion 14d. The pattern 15a on the leftmost side corresponds to the opening start position, and the pattern 15b on the right of this pattern 15a corresponds to the minimum diaphragm, and the pattern width is sequentially expanded to the right by the width corresponding to each diaphragm value. The conductive pattern 15c having a width corresponding to the maximum aperture (for example, F2.8) is formed at the rightmost end. The conductive pattern 15 is in contact with the pattern switch 16 as the opening amount detecting means having the contact pieces 16a and 16b, and the drive gear 14 is rotated as the conductive or non-conductive state between the contact pieces 16a and 16b. The position is detected.

Next, the sectors 1a and 1b, which are shutter blades that also serve as diaphragms
The open / close drive shutter drive unit is disposed behind the drive gear 14, and the sector open / close pin 17a and the cam engagement pin 17b set up on the sector opening lever 17 are provided in the sectors 1a and 1b, respectively. The opening / closing inclined long holes 1c and 1d are fitted in the cam groove 14a provided in the drive gear 14.

The cam opening lever 17 is an inverted V-shaped lever, and the fulcrum at the center thereof is rotatably pivotally attached to a support shaft 19 fixed near the tip of the sector closing lever 18. The sector opening / closing pin 17a is extended to one arm end extending upward, and the cam engaging pin 17b is extended to the other arm end extending obliquely downward leftward.
Are planted individually.

The sector closing lever 18 is formed of a substantially linear arm member having substantially the same length as that of the sector opening / closing lever 17, and its upper base end portion is pivoted on a support shaft 20 fixed to a stationary member. It is freely fitted, and a receiving shaft 18a that supports the armature 21 is planted at the tip of the free end portion that extends downward, and the support shaft 19 is provided at the upper left of this receiving shaft 18a. ing. A small hole 18b is provided at the free end of the sector closing lever 18, and a tight coil spring 22 is applied to the small hole 18b to urge the sector closing lever 18 to the left. However, the rotation of the lever 18 due to this biasing force is
The flatness is prevented by fitting the cam engagement pin 17b of the lever 17 into the cam groove of the smallest diameter portion of the cam groove 14a. Also, the armature 21 is a small piece with a convex shape,
It is attached to the lever 18 by rotatably fitting the substantially central portion thereof to the receiving shaft 18a. A magnet 23 having a horizontal U-shaped core 23a is arranged on the right side of the armature 21.

The sector shutter 1 is composed of two sickle-shaped sectors 1a and 1b forming shutter blades that also serve as diaphragms. The sectors 1a and 1b are arranged so as to face each other and overlap each other. The base is rotatably supported by support pins 24a and 24b that are erected on a shutter support plate (not shown), and inclined long holes 1c and 1d that are provided near the base and that overlap with each other are provided.
The sector opening / closing pin 17a is inserted through the common opening. The exposure opening 1e is opened and closed by the movement of the sector opening / closing pin 17a.

Next, the control circuit for controlling the flashmatic device will be described with reference to FIG. The output of the pattern switch 16 that measures the conductive pattern 15 indicating the opening amount of the sectors 1a and 1b is input to the microcomputer 31.
The output of the AE metering unit 32, which converts the brightness of the subject light into an analog output corresponding thereto, is input to the microcomputer 31 after the analog value is converted into a digital value by the A / D converter 33. . The distance signal input unit 34 outputs the distance measurement signal based on the distance measurement signal from the automatic distance detection device or the distance setting signal from the distance ring manually set.
Is input to The output of the distance signal input section 34 is input to the microcomputer 31 via the A / D converter 33. The output of the film sensitivity input degree 35 that generates an electrical output according to the film sensitivity value is also input to the microcomputer 31. A guide number of a flash light emitting device (not shown) provided separately or integrally with the camera body is input to the microcomputer 31 via the guide number input unit 36.

The microcomputer 31 controls the motor 11, the magnet 23, and the trigger circuit 39 according to the flowchart described later based on the input aperture value information, subject brightness information, distance measurement information, guide number information, and film sensitivity information. A motor control signal output from the microcomputer 31 is input to a motor drive circuit 37, and the motor 11 is drive-controlled based on this motor control signal. The magnet control signal output from the microcomputer 31 is input to the magnet drive circuit 38 to control the magnet 23. Further, the trigger signal output from the microcomputer 31 is input to the trigger circuit 39, which causes the flash light emitter to start emitting light.

Next, the operation of the flashmatic device of the present embodiment configured as described above will be described using the flowcharts shown in FIGS. 4 (A) to 4 (C).

First, the user of the camera turns the camera toward the subject with the main switch (not shown) closed, for example, by turning on the power switch of the camera or pressing the release button halfway. Then, the distance measuring signal from the automatic distance detecting device or the distance setting signal from the distance ring manually set is input to the microcomputer 31 from the distance signal input unit 34 as the photographing distance signal (d). Furthermore, AE metering unit 32
The subject light brightness B is input from the film sensitivity input section 35 to the film sensitivity S, and the guide number input section is input from the guide number G of the flashlight emitter to the microcomputer 31. Based on these values, the proper exposure amount E is input. E = K / BS ...... (1), the aperture value F _'FM for flash-Matic Is calculated and converted into a value (F _FM ) corresponding to the pattern of the conductive pattern 15 and stored. (Here, it is assumed that the film sensitivity S is input as ISO sensitivity.) Next, when the shutter release button is pressed, the magnet 23 and the motor 11 are energized. In this state, the gap between the magnet 23 and the armature 21 is relatively large, so the armature 21 is not attracted to the magnet 23, and the magnet 23 is only in the excited state. When the motor 11 is energized, the output gear 12 of this motor 11
As shown by the arrow (a) in FIG. 2, a counterclockwise direction (hereinafter,
It is called forward rotation). By this normal rotation, the intermediate ga 23
The drive gear 14 also rotates in the forward direction via. Due to the normal rotation of the drive gear 14, the cam engagement pin 17b fitted in the cam groove 14d is
Since the radius from the center O gradually increases, the pin 17b moves counterclockwise, and the lever 17 also rotates counterclockwise about the sector opening / closing pin 17a. Accordingly, the sector closing lever 18 rotates counterclockwise against the coil spring 22 about the support shaft 20 as a fulcrum via the support shaft 19, and eventually the armature 21 is pressed and attracted to the magnet 23 which is excited. To be done. The microcomputer 31
From the start of the normal rotation of the motor 11, the internal oscillator and counter measure a fixed time, and when this fixed time elapses, a reverse rotation signal is output to the motor drive circuit 37 to reverse the rotation of the motor 11. At this time, since the armature 21 of the sector closing lever 18 is attracted to and held by the magnet 23 which is energized, the sector closing lever 17 rotates clockwise about its supporting shaft 19 as a fulcrum. This rotation also moves the sector opening / closing pin 17a in the clockwise direction.
a and 1b start the opening operation. At the same time, exposure control, which will be described later, is performed, and when the proper exposure amount according to the brightness of the subject is obtained, the power supply to the magnet 23 is cut off. Then, the armature 21 is released from the magnet 23, so that the sector closing lever 18 is a coil spring.
It is pulled to the left by 22 and rotates clockwise about shaft 20 as a fulcrum. Therefore, since the sector opening lever 17 rotates counterclockwise with the cam engagement pin 17b as a fulcrum, the sector opening / closing pin 17a also rotates counterclockwise, and as a result, the sectors 1a and 1b are close. That is, proper exposure can be obtained during this period.

Here, the principle of exposure control used in this embodiment will be described. Assuming that the aperture value is F, the exposure time is T, the subject brightness is B, and the film sensitivity is S, the relationship K / BS = T / F ² (3) must be established to obtain the proper exposure. is there. Here, K is a constant.

FIG. 5 shows changes in the aperture value of the sector shutter with the shutter release operation. Aperture is F2.8 ~
Considering a camera with up to F16, when the shutter release is performed at time t0, the shutter sector starts to open and
F16 at t1, F11 at time t2, F8 at time t3, F at time t4
5.6 …… At time t6, the aperture value changes to F2.8. However, since the opening degree of the sector shutter is not always constant, the time interval changes depending on these conditions. Here, a minute constant time is ΔT, and an intermediate value between the aperture value Fn before the aperture is changed by one step from Fn to Fm and the aperture value Fm after that is the aperture value F′n, and (n = 0 , 16,11,8,5.6,4,
m = 16,11,8,5.6,4,2.8) During the time when the aperture changes from Fn to Fm, the approximate value is calculated by assuming that the aperture value does not change at F'n, and it is obtained during this ΔT. Exposure value is 5th
The shaded portion shown in the figure, that is, ΔT / (F′n) ² . Therefore, for example, the total exposure amount after time t2 from the time of shutter release is expressed as follows: F (t) is the aperture value at time t Becomes Here, as described above, F'o is the aperture value at approximately the middle of the shutter sector opening until it reaches F16,
F'16 is an aperture value that is approximately in the middle from F16 to F11. That is, the total exposure amount after the time T is Becomes

From these equations (3) and (5), the value obtained by integrating the exposure amount ΔT / (F′n) ² at ΔT time and K calculated in advance
It can be seen that proper exposure can be obtained by closing the shutter when / BS becomes equal.

Now, returning to the flowchart shown in FIG. 4A, the exposure control and the flashmatic will be described.

When the motor 11 starts reverse rotation in the arrow (B) direction in FIG. 2, the drive gear 14 also starts reverse rotation. After the start of this reverse rotation, the pattern switch 16 turns the minimum aperture of the conductive pattern 15 "F1
When the shutter operation start position pattern 15a provided immediately before the 6 '' pattern is detected, its output is set to the register RO provided in the microcomputer 31 with the proper exposure value K / BS, and ΔT / (F'O) ²
The first value of is set in register R1. Also (2)
The flashmatic aperture value F _FM obtained by the equation is set in the register R2.

In this state, as the drive gear 14 reversely rotates and the sector shutter 1 opens, the pattern switch 16 detects from the pattern corresponding to “F16” of the print pattern 15 to the pattern corresponding to “F2.8”. Whenever a detection signal is generated, the value of "ΔT / (F ') ² " is transferred from the ROM to the register R1. That is, ΔT / (F′16) ² , ΔT / (F′11) ² , ...
The value of is stored in ROM in advance, and the conductive pattern 1
The pattern of F16, F11, ...
Each time it recognizes, the corresponding value is transferred to the register R1. On the other hand, when there is no detection signal, the value of the register R1 is not updated and the process proceeds to the next step.

The pattern switch 16 detects a new pattern, transfers the value of "ΔT / (F ') ² " from the ROM to the register R1, and then the value of the register R2 in which the flashmatic aperture value F _FM is stored. Subtract one from. It is determined whether or not the content of the register R2 is O, that is, whether the flashmatic aperture value calculated in advance has reached R2 =
If it is O, the microcomputer 31 outputs a trigger signal to the trigger circuit 39 to cause the flash light emitter to emit light. If R2 ≠ O, the process proceeds to the next step.

Then, ΔT / (F′O) ² input to the register R1 is subtracted from the exposure determination value K / BS input to the register RO. At first, ΔT / (F′O) ² is stored in the register R1, so ΔT / (F ′ from the exposure determination value K / B · S.
O) ² is subtracted. The result of this subtraction is transferred to the register RO and the value of the register RO is updated. If the result of this subtraction is not zero or negative, it means that the exposure is not proper. At this time, it is next checked whether or not the maximum aperture value has been reached, and if it has not reached the maximum aperture value, wait for ΔT and then return to point l. The calculation time of the microcomputer 31 is not taken into consideration here. Then, as described above, ΔT / (F ′ is sequentially stored in the register R1 according to the rotation of the drive gear 24.
n) The value of ² is transferred, and each time the value is subtracted, the value of the register RO is updated to a smaller value.

When the pattern of the open aperture value is input, the microcomputer 31 outputs a signal to stop the motor 11 and returns to the point l repeatedly in this state until RO = 0. The calculation that repeats returning to the l point through the l point as described above repeats the subtraction, and ΔT / (F ′) ²
Is equivalent to performing the integration of. When the content of the register RO becomes zero as a result of this repetition, the integrated value T of ΔT / (F ′) ²
This means that / F ² has become equal to the exposure determination value K / BS, and the proper exposure has been obtained, so move to the next step.

In this step, first R2
When ≠ O, that is, when the aperture value for flashmatic is not reached before the proper exposure, the trigger signal is output to cause the flashlight emitter to emit light. Next, the microcomputer 31 sends an OFF signal to the magnet drive circuit 38 to bring the magnet 23 into a non-excited state. As a result, the sector shutter 1 is closed as described above. At this point, the motor 11 is still rotating in the reverse direction, so the time is kept for a certain period of time, and the cam engagement pin 17b moves to the end of the cam groove 14a.
After sufficiently applying to 14c, the microcomputer 31 outputs a stop signal to the motor drive circuit 37 and the motor 11 stops.

(Effects of the Invention) As described above, according to the flashmatic device for a camera of the present invention, a part of the sector shutter that gradually opens or a member mechanically interlocked with this moves at each moment during the movement. Is used to detect the opening amount of the sector shutter, and the flash light emitter is caused to emit light when the value calculated by the flash calculation means becomes equal to that of the flash shutter. The device can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the present invention, FIG. 2 is a front view of a sector shutter drive mechanism of a flashmatic device of a camera showing an embodiment of the present invention, and FIG. 3 is shown in FIG. A control electric circuit diagram of the flashmatic device of the camera, FIGS. 4 (A) to 4 (C) are flow charts of the flashmatic device of the camera shown in FIG. 2, and FIG. 5 is shown in FIG. The diagram which shows the opening characteristic of the sector shutter in the flashmatic apparatus of the camera shown, FIG. 6 is a diagram for explaining the principle of exposure control in the flashmatic apparatus of the camera shown in FIG. 1 ... Sector shutter 2 ... Aperture amount detection means (16 ... pattern switch) 3 ... Exposure control calculation means (31 ... microcomputer) 4 ... Flashmatic calculation means (31 ... microcomputer) 5 ... Flashmatic discrimination means (31 …… microcomputer) 6 …… Flash emission trigger means (39 …… trigger circuit)

Claims (1)

(57) [Claims] 1. An exposure amount determining means for determining a necessary exposure amount based on photographing information such as subject brightness and film sensitivity, a sector shutter in which an opening amount gradually increases from a closed position in association with a release operation, and the sector. An initial position detecting means for detecting an initial position of the shutter operation and outputting an initial position signal, and a pulse for generating a pulse signal with the movement of a part of the sector shutter or an interlocking member mechanically interlocked therewith. A generation unit, an aperture amount detection unit that detects the current aperture amount of the sector shutter based on the initial position signal and the pulse signal, and film sensitivity information, shooting distance information, and guide number information of the flash light emitter. Flashmatic calculation means for calculating the aperture value based on which the flash photography is performed with proper exposure, and the calculated value of the flashmatic calculation means A flashmatic determination means for comparing the corresponding values of the opening amount obtained from the opening amount detecting means and outputting a trigger signal when the two values match, and a flash light emission trigger for emitting a flash light emitting device upon receiving the trigger signal. Means, an exposure amount output means for outputting a product of the present opening amount and the minute time, in order to obtain an exposure amount for each minute time during the opening operation of the sector shutter, and an output by the exposure amount output means. Discriminating means for outputting an output when the total sum of the exposure amounts for each minute time that has been determined matches the exposure amount determined by the exposure amount determining means, and the closing operation of the sector shutter upon receiving the output of the determining means. A flashmatic device for a camera, comprising: a shutter closing means for performing the following.