JPH03261929A - Camera - Google Patents

Abstract

PURPOSE:To accomplish rapid photographing in accordance with the intension of a photographer by prioritizing an action in response to a switch when the switch for starting a photographing action is operated in a specified time after the charged voltage of a main capacitor attains a specified value. CONSTITUTION:A timer Ti for setting a stroboscope charging time which is different in accordance with a charged state is incorporated in a microcomputer MPS, and the main capacitor C1 is charged by controlling a booster circuit DD1 preceding photographing by the use of the stroboscope. Charging is continued for the specified time after a charging level attains the specified value, but when a releasing operation is performed in the specified time after the charging level attains the specified value, the action charging the main capacitor 1 further is stopped so as to directly shift the photographing action. Thus, the rapid photographing in accordance with the intension of the photographer is accomplished.

Description

[Detailed Description of the Invention] (Field of Application of the Invention) According to the present invention, when it is detected that the charging voltage of the strobe main capacitor has not reached a predetermined value, the booster circuit is activated to start the charging operation. The present invention relates to a strobe charging control device having means for continuing the charging operation for a first predetermined time even after the charging voltage reaches a predetermined value.

(Background of the Invention) Conventionally, prior to photography, the main capacitor of a flash device is charged to a voltage sufficient for flash photography in response to the operation of switch means such as an aperture set switch, a shutter speed set switch, and a release inhibit switch. There is a camera that continues charging for a predetermined period of time in order to obtain a sufficient amount of light. There was a problem that it could not be done.

(Object of the Invention) An object of the present invention is to solve the above-mentioned problems and provide a camera that can quickly take pictures according to the photographer's intention.

(Features of the Invention) In order to achieve the above object, the present invention detects that the switch means for starting the photographing operation is operated within a predetermined time after the charging voltage of the main capacitor reaches a predetermined value. When the charge voltage of the main capacitor reaches a predetermined value for performing strobe photography, a control means is provided that prohibits further charging operation by the charging control means and shifts to the photographing operation. The present invention is characterized in that even during a charging operation that is performed thereafter in order to obtain a sufficient amount of light emission, priority is given to the operation in response to the switch means for starting the photographing operation.

(Embodiments of the Invention) Hereinafter, the present invention will be described in detail based on illustrated embodiments.

FIG. 1 is a block diagram of a camera including an embodiment of the present invention. In the diagram, MPS is a microcomputer (hereinafter referred to as microcomputer) that controls various functions of the camera, and internally the MPS is a microcomputer that controls various functions of the camera. It has a timer Ti (Ts to T6) that sets different strobe charging times. COD
is a distance measuring photometer circuit including a plurality of line sensors composed of COD, and the start and stop of accumulation is controlled by signals from the microcomputer MPS via the distance measuring circuit AFU, which will be described later.
The accumulated image data is transmitted to the ranging circuit AFU. AFU
is a distance measuring circuit that transmits image data from the distance measuring photometer COD to the microcomputer MPS, and LES is a lens driving circuit that controls an actuator that drives the lens back and forth based on a signal from the microcomputer MPS. The LSU has a sensor for photometry at the periphery of the subject and a sensor for photometry at the center of the subject, and a photometry circuit that transmits the photometry values from each sensor to the microcomputer MPS.The TAD controls the shutter, aperture, and film feed based on signals from the microcomputer MPS. This is a shutter/aperture/feed control circuit that controls the

Each of the aforementioned circuits CCD, AFU, LES, LSU, TAD
In each case, signals are exchanged with the microcomputer MPS through multiple signal lines, which is indicated by a ← mark on the circuit.

AUX is a strobe circuit that is connected to the microcomputer MPS through three communication lines and serves as an auxiliary light source during shooting.
The detailed circuit is shown in FIG.

LM is a photometering circuit for a strobe installed in the camera, switch SW3 is a switch that opens in synchronization with the closing of a synchro switch shown in FIG. This is a photodiode that measures the reflected light. COMP is a comparator with one input connected to the connection point between the integrating capacitor Ci and the photodiode FD, the other connected to the voltage source VI that changes depending on the film speed, and the output connected to the terminal EST of the strobe circuit AUX. be.

SWl is O at the first stroke of the camera release button.
SW2 is a switch that turns on when the camera's release button is pressed, and LSW is a so-called release switch that turns on and prohibits detection of the status of all switches except for switch LSW, that is, prohibits photographing operations. It is a prohibition switch.

FIG. 2 is a detailed circuit diagram of the strobe circuit AUX.

In FIG. 2, BATI is a power source battery. DDl is a known boosting circuit driven by the power supply battery BATI, which prohibits boosting operation when the terminal FCG is at low level, and performs boosting operation when it is at high level.

Dl is a diode connected to rectify the output of the booster circuit DDI and charge the main capacitor C1. R
1, R2・ is a resistor, COMP 1 is a comparator, these form a voltage detection circuit, and the main capacitor C
1 is charged to a predetermined value, the comparator COMP
1 output, that is, the terminal CCC changes from low level to high level.

Hereinafter, the state in which the output of the comparator COMP1 is at a high level will be referred to as a charging completion state. X is a synchro switch synchronized with the camera shutter, and is closed when the shutter is fully open.

NAND l is a Nandt gate, one input is connected to the terminal FIN, and the other terminal is connected to the synchro switch X and the resistor R5. R3 is a resistor connected to the output of the NAND gate NAND1, and one end is connected to the gate of the thyristor 5CRI. R4 is a resistor connected between the gate and cathode of the thyristor 5CRI, R6 and C2 are resistors and capacitors, respectively, and T1 is a trigger transformer.

The thyristor 5CRI, resistors R4 and R6, capacitor C2, and trigger transformer T1 form a known trigger circuit for a xenon discharge tube.

FLI is a xenon discharge tube, and the light energy from it is used as an auxiliary light source during photography. Ll is a current limiting inductance, and 5CR2 is a thyristor connected in parallel with the xenon discharge tube FLI.

R7 and R8 are resistors, and resistor R8 is connected to terminal FST. When the terminal FST becomes high level, the thyristor 5CR2 is turned on.

TRI is a transistor whose emitter is grounded, whose collector is connected to the terminal FST via a resistor R8, and whose base is connected to the terminal FIN via a resistor R9 and an inverter 1NTl.
When the terminal FST is at high level, the thyristor 5
Prevent CR2 from turning ON.

Next, the operation will be explained using the flowchart shown in FIG.

When a power switch (not shown) is turned on, power is supplied to the microcomputer MPS by the power supply battery BATI, and the microcomputer MPS is set to an initial state.

[Step 1: The initial state.

[Step 2] Release prohibition switch LSW is OFF
If so, proceed to step 3; if ON, return to step 2.

[Step 3] If the terminal CCC is at a high level, that is, the main capacitor C1 is sufficiently charged, the process proceeds to step 11, and if it is at a low level, the process proceeds to step 4.

[Step 4] The terminal FCG is set to high level, and the operation of the booster circuit DD1 is started. This starts charging the main capacitor C1.

[Step 5] Start timer T1's timing operation. Usually, the time it takes for the timer T1 to time up is set to be slightly longer than the time required for the main capacitor C1 to reach a fully charged state, and it times out in about 5 to 10 seconds.

[Step 6] Determine whether or not the timer T1 has timed up. If the timer T1 has timed up, proceed to step 15; if not, proceed to step 7.

[Step 7] The level of the terminal CCC is detected, and if it is at a high level, that is, in a charging completed state, the process proceeds to step 8, and if it is not at a low level, that is, in a charging completed state, the process returns to step 6.

[Step 8] Start timer T2's timing operation. Normally, the time until timer T2 times out is several tens of milliseconds to about 2 seconds, which is shorter than the timer T1, and the main capacitor is charged to a higher voltage after reaching the charging completion state.

[Step 9] If the switch SW1 is ON, the process proceeds to step 24; if it is OFF, the process proceeds to step 10.

[Step 10] Determine whether or not timer T2 has timed up. If timed up, proceed to step 1.
Proceed to step 5, and if not, return to step 9.

In step 3, if the terminal Ccc is at a high level, that is, if the main capacitor C1 is sufficiently charged, the process proceeds to step 11 as described above.

[Step 11] Operates in the same manner as Step 4, and starts charging the main capacitor C1.

[Step 12] Start the timing operation of timer T5.

This timer T5 time may be shorter than the time until the timer T2 times out, or may be approximately "0".

[Step 13] Determine the state of switch SW1,
If it is ON, the process proceeds to step 24, and if it is OFF, the process proceeds to step 4.

[Step 14] Determine whether or not timer T5 has timed up. If timed up, proceed to step 15.
If not, return to step 13.

[Step 15] The terminal FCG is set to low level, and the boosting operation of the boosting circuit DDI is prohibited.

[Step 16] Determine the state of switch SW1 and turn O
If N, the process advances to step 17; if OFF, the process returns to step 16.

[Step 17] Detect the level of the terminal CCC, and if it is high level, proceed to step 28, and if it is low level, proceed to step 18.

[Step 18] Operates in the same manner as Step 4, and starts charging the main capacitor C1.

[Step 19] Start the operation of timer T3. This timer time is approximately the same as the time-up time of the timer T□.

[Step 20] Determine whether or not the time T3 is up. If the time is up, proceed to step 2.
Go to step 5, and if not, go to step 21.

[Step 21] Detect the level of the terminal CCC, and if it is high level, go to step 22, and if it is low level, go back to step 2o.

[Step 22] Start the operation of timer T4. This timer time is approximately the same as the time-up time of the timer T2.

[Step 23] Determine whether or not the timer T4 has timed up. If the timer T4 has timed up, proceed to step 24.
If not, return to step 23.

[Step 24] The terminal FCG is set to low level, and the boosting operation of the boosting circuit DD1 is prohibited.

[Step 28] Here, the distance measuring photometer circuit CCD, distance measuring circuit AFU, and lens drive circuit LES shown in FIG.
performs an automatic focusing operation, and also performs a photometry operation using a photometry circuit LSU.

[Step 29] Based on the result of the photometry operation, it is determined whether the surroundings are in a dark state or in a backlit state, for example, and if a strobe is required in a dark state or in a backlit state, the process proceeds to step 30; In the opposite case, proceed to step 31.

[Step 30] Terminal FI to strobe circuit ALJX
When N is set to high level and the X contact is turned on, the xenon discharge tube FLI is set in a state where it can emit light, and when the terminal FST is set to high level, Cyrisk 5CR2 is set.
is turned on. Further, based on the photometric value in step 28, aperture and shutter speed information suitable for strobe photography is determined.

[Step 31] Based on the photometry result in step 28, aperture and shutter speed information suitable for natural light photography is set. In addition, even if the terminal FIN is set to low level, the xenon discharge tube FLI is prohibited from emitting light even if the
2 is prohibited from turning ON.

In step 20, if time T3 is up, the process proceeds to step 25 as described above.

[Step 25] Here, the terminal FCC is set to low level, and the boosting operation of the boosting circuit DDI is prohibited.

[Step 26] Similar to step 28, a focusing operation and a photometry operation are performed.

[Step 27] Based on the photometry result in step 26, aperture and shutter speed information suitable for natural light photography is set. In addition, the terminal FIN is set to low level, and even if the
is prohibited from turning on.

When the operations in steps 27, 30 or 31 described above are completed, the process proceeds to step 32.

[Step 32] Here, the state of the switch SW2, which is turned ON at the second stroke of the release switch shown in FIG.
If F, the process returns to step 32.

[Step 33] Step 27.30 or Step 3
Execute the photographing operation in the state set in 1.

When the photographing operation is performed based on the state of step 30, the shutter/aperture/feeding circuit TAD shown in FIG.
When the shutter (not shown) starts operating and becomes fully open, the synchro switch X turns on and the xenon discharge tube FLI
starts emitting light. At the same time, the switch SW3 is turned off, the reflected light from the subject is integrated by the capacitor Ci, and when it reaches a predetermined value, the comparator COMP
The output of the xenon tube L1 becomes high level, and the thyristor 5CR2 is turned on via the terminal FST to stop the xenon tube L1 from emitting light. Thereafter, the shutter starts closing, and when this is completed, one frame of film is wound.

When the operation is performed based on the state of step 27 or 31, the shutter/aperture/feed circuit TAD of FIG. 1 narrows down the aperture to an aperture value suitable for natural light, and performs shutter control. At this time, the synchro switch X is turned on, but since the terminal FIN is at a low level, no light is emitted. There is also a possibility that the switch SW3 is turned off and a high level signal is given to the terminal FST of the strobe circuit AUX, but the terminal FIN is at a low level and the transistor TRI
is turned on, so Cyrisk5CR2 will never turn on. Thereafter, when the shutter operation is completed, winding for one frame of film is performed.

[Step 34] The series of operations ends.

After the above step 33 is completed, a sequence for charging the main capacitor C1 again may be added. An example of this is shown in FIG. The operation will be explained below.

After step 33 in FIG. 3 is completed, the process proceeds to step 35.

[Step 35] If the terminal CCC is at high level, that is, the main capacitor C1 is sufficiently charged, step 4 is performed.
The process proceeds to step 3, and if the level is low, the process proceeds to step 36.

[Step 36] The terminal FCC is set to high level, and the operation of the booster circuit DDI is started. This starts charging the main capacitor C1.

[Step 37] Start timer T6's timing operation.

The time taken until the timer T6 times out is approximately the same as that of the timer T1.

[Step 38] Determine whether or not the timer T6 has timed up. If the timer T6 has timed up, proceed to step 42.
If not, proceed to step 39.

[Step 39] Determine the level of the terminal CCC. If the level is high, proceed to step 4o, and if it is low, return to step 38.

[Step 40] Timer T7 starts.

The time until timer T7 times out is timer T2.
It is slightly longer than 2 to 3 seconds.

[Step 41] Determine whether or not the timer T7 has timed up. If the timer T7 has timed up, proceed to step 42.
If not, return to step 41.

[Step 42] The terminal FCG is set to low level, and the boosting operation of the boosting circuit DDI is prohibited.

In step 35, the terminal CCC is at a high level;
That is, if the main capacitor C1 is sufficiently charged, the process proceeds to step 43 as described above.

[Step 43] The terminal FCC is set to high level, and the operation of the booster circuit DDI is started. This starts charging the main capacitor c1.

[Step 44] Start timer T day clocking operation.

The time taken until timer T8 times out is approximately the same as that of timer T4.

[Step 45] It is determined whether or not the timer T8 has timed up. If the timer T8 has timed up, the process proceeds to step 42 described above; if not, the process returns to step 45.

[Step 46] The series of operations ends.

According to this embodiment, the main capacitor C1 is charged prior to flash photography, and after the charge level reaches a predetermined value, charging is continued for a predetermined time, but when the charge level reaches the predetermined value. If the release operation is performed within a predetermined time after that, the further charging operation to the main capacitor c1 is stopped and the shooting operation is immediately started (steps 9 to 24, step 1).
3-Step 24), rapid photography can be performed according to the photographer's intention.

(Correspondence between the invention and the embodiments) In this embodiment, the portion of the microcomputer MPS that performs the operation of step 3 shown in FIG. 3 or step 35 of FIG. The part that performs the operations from steps 11 to 14 is the charging time control means, and the part that performs the operations from step 9. The parts that perform the operation of step 13 correspond to control means. Further, the switch SW1 corresponds to a switch means for starting photographing.

(Modified Example) In this embodiment, an example has been described in which the boost operation is performed by canceling a switch not directly related to the release operation, here the release prohibition switch LSW, but the switch LSW
The same effect can be obtained by replacing or additionally using other shooting information set switches such as an aperture set switch or a shutter speed set switch, or a switch SW1 driven by the first stroke of the release button. It will be done.

Also, Fig. 2 shows a so-called parallel control strobe circuit AUX.
However, similar effects can be obtained by using a so-called series control circuit.

(Effects of the Invention) As explained above, according to the present invention, it is detected that the switch means for starting the photographing operation is operated within a predetermined time after the charging voltage of the main capacitor reaches a predetermined value. When the charge voltage of the main capacitor reaches a predetermined value for performing strobe photography, a control means is provided that prohibits further charging operation by the charging control means and shifts to the photographing operation. In order to obtain a sufficient amount of light, even during the charging operation that continues after that, priority is given to the operation that responds to the switch means for starting the shooting operation, so that the operation that corresponds to the photographer's intention is given priority. It becomes possible to perform quick photographing.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a circuit diagram showing details of the strobe circuit shown in FIG. 1, and FIG. 3 is a flowchart showing the operation of an embodiment of the present invention.
FIG. 4 is a flowchart showing the operation of a partially modified portion of FIG. MPS...Microcomputer, AUX...Strobe circuit, LM-...Strobe metering circuit, LS
W...Release prohibition switch, SW 1.
SW2”...Switch. Step 33 Fig. 4

Claims (1)

[Claims] (1) Discrimination means that determines the state of charge from the output of a detection means that operates after a change in the state of the switch means operated prior to photographing and detects the charging voltage of the main capacitor, and the determination means determines the charging voltage at a predetermined level. When it is determined that the predetermined value has not been reached, the booster circuit is activated to start the charging operation, and even after it is determined that the predetermined value has been reached, the charging control means continues the charging operation for a predetermined time. In the camera equipped with the above-mentioned camera, when it is detected that the switch means for starting the photographing operation is operated within the predetermined time after the charging voltage of the main capacitor reaches the predetermined value, the charging control means performs an update. A camera characterized in that it is provided with a control means for prohibiting a charging operation and shifting to a photographing operation.