JPH05150301A - Flash communicating method of camera - Google Patents

Abstract

PURPOSE:To shorten the time of shutter releasing operation. CONSTITUTION:A release magnet is turned on a delay time Td after a release switch SWR is turned on, and then mirror-up operation is started. Then EE pulses are outputted and stopping-down operation is started. A flash communication is carried on from the time when release magnet is turned on to the time when a stop control magnet (EE) is turned on. The flash communication is performed even after the release magnet is turned on, so flash light is emitted according to the latest information. Further, the flash communication exerts no influence upon the ON operation of the release magnet, so the ON operation is quickened and the shutter release operation time is shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera flash communication method.

[0002]

2. Description of the Related Art In the conventional photographing operation using a flash,
Flash communication, in which information necessary for flash emission is transmitted between the flash and the camera body, is executed in the initial stage of the shutter release operation. That is, from the flash to the camera body side, a charging completion signal or the like indicating that charging of the power supply of the flash is completed is transmitted, and from the camera body to the flash side, a flash emission permission signal
Signal indicating the shooting mode of the camera and ISO of film
A signal or the like indicating the sensitivity is transmitted. This flash communication is executed after the release switch is turned on,
After the flash communication, the release magnet is turned on, that is, the locked state of the mirror is released and the mirror starts to move up. As the mirror rises, the aperture is stopped down to the set state, and then the shutter curtain runs.

[0003]

As described above, conventionally, after the release switch is turned on, flash communication,
The raising of the mirror, the focusing operation, and the movement of the shutter curtain are sequentially performed. However, when the mirror is raised and the aperture is narrowed down after the flash communication in this way, the time from when the release switch is turned on until the shutter curtain starts running, that is, the shutter release operation is performed. There is a problem that the time (release time lag) becomes long. The present invention has been made for the purpose of providing a flash communication method capable of shortening the shutter release operation time and more appropriately controlling the flash emission amount.

[0004]

A flash communication method according to the present invention is carried out after flash communication starts a mirror-up operation for displacing a mirror to a raised position and a diaphragm operation for changing an aperture to a set state. It is characterized by being done.

[0005]

The present invention will be described below with reference to the illustrated embodiments.
FIG. 1 shows a circuit configuration of a control system of a camera for implementing a flash communication method according to an embodiment of the present invention.

The CPU 31 and the DPU 32 both include a microcomputer and are connected to each other. CP
U31 performs various calculations such as exposure control and shutter release control and sequence control, and DPU32 performs reading of signals from various switches, various displays and flash communication.

The photometric circuit 41 is connected to the CPU 31 via an AD converter 42. In the AD converter 42,
A diaphragm volume 43 is connected. The diaphragm volume 43 works in conjunction with a diaphragm ring (not shown) of the taking lens 16,
An aperture value corresponding to the rotational position of the aperture ring is output as an aperture voltage. This aperture voltage is converted into a digital value corresponding to the aperture value Av by the AD converter 42, and the CPU
31 is input. The CPU 31 operates the AD converter 42 at a predetermined time to read the subject brightness signal and the aperture value signal set in the taking lens 16, and convert the signal into a corresponding apex value.

The wind motor 44 winds and rewinds the film, and the mirror motor 45 moves the mirror up and down. The operations of the motors 44 and 45 are controlled by the CPU 31 via the motor drive circuit 46. The shutter aperture control circuit 47 controls the release operation and the aperture stop operation of the taking lens 16 when the shutter button (not shown) is fully pressed. The shutter aperture control circuit 47 includes a shutter magnet ES1. , ES2, aperture control magnet EE, and release magnet RL are connected. The shutter magnets ES1 and ES2 hold the front curtain and the rear curtain of the shutter at the charge position, the diaphragm control magnet EE holds the diaphragm at the set position, and the release magnet RL holds the mirror at the down position.
The EE pulse counter 48 counts the EE pulse from an EE pulse generating circuit (not shown) in response to the narrowing operation and outputs it to the CPU 31.

Further, the CPU 31 is provided with terminals P10 to P14 for reading DX codes (DX2 to DX6) provided on the film cartridge.
The ISO speed of the film is detected from the X code.

The taking lens 16 is connected to the DPU 32. The DPU 32 performs lens communication with the taking lens 16 and reads lens data such as the open F number Fmin, the maximum F number Fmax, and the focal length f.

The DPU 32 has a main switch SW.
MAIN, photometric switch SWS, release switch SW
Other than R, various switches SWMODE, SWDRIV
E, SWEF, switches SWISO, SWCL, SWU
P and SWDOWN are respectively connected. The main switch SWMAIN works in conjunction with the main switch. The photometric switch SWS and the release switch SWR are normally open switches that interlock with the shutter button. The photometric switch SWS is turned on by half-pressing the shutter button, and the release switch SWR is turned on by fully pressing the shutter button. The other switches are not directly related to the present embodiment, and the description thereof will be omitted.

An LCD display panel 52 is connected to the DPU 32. The LCD display panel 52 displays the exposure mode, the shutter speed Tv, the aperture value Av, the number of shots, etc. under the control of the DPU 32.

The flash 53 is connected to the CP via the X contact 54.
It is connected to U31 and performs flash communication with DPU32. This flash communication is transmission and reception of various data necessary for driving the flash 53 between the flash 53 and the camera body. That is, in flash communication, from the flash 53 to the camera body side, a charge completion signal indicating that charging of the power source of the flash is completed, a signal indicating whether the flash 53 is attached to the camera body, or the like is transmitted. .. Further, from the camera body to the flash 53 side, a flash light emission permission signal, a signal indicating the photographing mode of the camera, a signal indicating the ISO sensitivity of the film, and the like are transmitted.

The TTL light control circuit 55 detects the amount of light emitted from the flash 53 by detecting the reflected light of the subject,
A signal according to this light emission amount is output to the DPU 32. DP
U32 stops the light emission of the flash 53 based on this signal.

Next, the shutter release operation will be described with reference to FIG. The shutter button is pressed halfway to turn on the metering switch SWS, and then press the shutter button fully to release switch S
The WR is turned on. Then, after a certain delay time Td, the release magnet is turned on, and the mirror is held in the down position only by this magnet. Then the release magnet is turned off and the mirror begins to move up. Further, almost simultaneously with this, an EE pulse is output, and the diaphragm is narrowed according to this pulse.
When the number of pulses reaches a value corresponding to the set aperture value, the aperture control magnet EE is turned on and the aperture is held in a predetermined state.

Conventionally, flash communication has been performed from the time when the release switch SWR is turned on (reference A) to the time when the release magnet is turned on (reference B), but in the present embodiment. , Release switch SWR
Is performed from the time when is turned on (reference A) to the time when the aperture control magnet EE is turned on (reference C). In other words, in this embodiment, the flash communication is performed even after the mirror-up operation for displacing the mirror to the raised position and the aperture operation for changing the aperture to the set state are started. That is, in the present embodiment, the end time of the flash communication is later than that of the related art and the time of the flash communication is longer than that of the related art.

When the release magnet is turned on (reference B), at the same time, the shutter magnet ES
(Reference symbols ES1 and ES2 in FIG. 1) are turned on, and the front curtain and the rear curtain of the shutter are held at predetermined positions. After that, when a certain amount of time has passed since the release magnet was turned off and the mirror is considered to be stable in the raised position, the shutter magnet ES1 holding the front curtain is turned off (reference D). As a result, the front curtain runs (reference E). After a lapse of a predetermined time from the running of the front curtain, the shutter magnet ES2 holding the rear curtain is turned off (reference F), whereby the rear curtain runs (reference G).

When the running of the front curtain is completed, a light emission trigger signal is output from the CPU 31 (reference numeral H), whereby the flash starts emitting light (reference numeral I). When the amount of light emission reaches a predetermined value, the DPU 32 sends a quench signal (reference code Q).
Is output, which causes the flash 53 to stop emitting light.

FIG. 3 is a flowchart of a release operation program executed by the CPU 31. In step 101, communication is performed between the CPU 31 and the DPU 32, and the CPU 31 outputs to the DPU 32 a command signal to perform flash communication. This makes D
The PU 32 starts flash communication, and in parallel with this, the CPU 31 performs various calculations and sequence control. That is, in step 102, the release magnet and the shutter magnet are turned on. Next, at step 103, the release magnet is turned off, the mirror starts to move up, and the EE pulse is output to start narrowing down.

In this way, while the CPU 31 controls the release magnet and the like, flash communication is performed in the DPU 32, and in step 104, D
The result of the flash communication is input from the PU 32 to the CPU 31.

In step 105, the shutter magnet of the front curtain is turned off and the front curtain runs. Next, at step 106, it is determined whether the flash power supply has been fully charged. When the charging is completed, step 107 is executed, the light emission trigger signal is output, and the flash 53 starts light emission. Next, at step 108, the quench control is performed, a high signal is output from the quench (Q) terminal, and the flash 53 stops emitting light. When the flash emission is stopped, it is determined in step 111 whether or not a predetermined time has elapsed from the running of the front curtain, and when the predetermined time has elapsed, step 1
In 12, the shutter magnet of the front curtain is turned off, and the rear curtain runs. That is, this predetermined time is the shutter speed. When the set shutter speed is shorter than the flash synchronization speed, the shutter speed is set to the flash synchronization speed in step 111.

On the other hand, if it is determined in step 106 that charging has not been completed, step 111 is immediately executed, and after a predetermined time has elapsed, the rear curtain runs in step 112. That is, the predetermined time at this time is a preset shutter speed.

At step 113, it is judged if the traveling of the rear curtain is completed. When the running is completed, the program ends, and the wind control is continuously performed to wind the film.

As described above, in the present embodiment, the flash communication is performed after the release magnet is turned on, that is, during the narrowing operation. Therefore, the photometry result during this period, that is, the latest information, is controlled by the flash 53. It is possible to make the light emission amount of the flash 53 a more appropriate value. Further, in this embodiment, since the flash communication does not affect the ON operation of the release magnet, this ON operation can be accelerated and the delay time Td can be shortened. As a result, the shutter release operation time (release time lag) can be shortened. Also, since the time that can be allocated to flash communication can be increased, the amount of information exchanged between the camera and the flash can be increased. Further, in this embodiment, unlike the conventional case, the flash communication is not stopped due to the release magnet being turned on, so the flash 53 outputs a completion signal after the release magnet is turned on. Even in this case, the flash 53 can be made to emit light.

In the above embodiment, the flash communication is configured to be ended by the ON operation of the aperture control magnet EE. However, the communication time is further extended to the start of the shutter curtain (reference D). You can

[0026]

As described above, according to the present invention, it is possible to reduce the time required for the shutter curtain to start traveling.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a control system of a camera that implements a flash communication method according to an embodiment of the present invention.

FIG. 2 is a diagram showing a timing chart of a shutter release operation.

FIG. 3 is a flowchart showing a release operation.

[Explanation of symbols]

 31 CPU 32 DPU 53 Flash

Claims (1)

[Claims] 1. A flash that transmits at least a charge completion signal indicating that charging of the power supply of the flash has been completed from the flash to the camera body side and at least a flash emission permission signal from the camera body to the flash side. A flash communication method for a camera, characterized in that the flash communication is performed after starting a mirror-up operation for displacing a mirror to a raised position and a narrowing-down operation for changing an aperture to a set state. ..