JPH0243522A - camera - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Use] The present invention relates to a camera that uses a flash device (strobe) and is capable of macro photography and general photography.

[Prior Art] In recent years, camera technology has progressed and the functional system of cameras has been enriched, making it possible to take a variety of pictures with just one camera. In particular, with an eye-reflex camera, by attaching various lenses and strobes to the body, it is possible to take a wide variety of shots, including close-up and telephoto shots.

In addition, a strobe is built into the body of a single-lens reflex camera,
Systems that include strobes are becoming more compact, and strobe lighting is becoming more automated, such as using a split metering sensor to measure the +i shadow per screen, and automatically firing the strobe when the subject is dark or backlit.

[Problem that the invention is trying to solve] However, even if a camera has many functions, if you use it incorrectly, the photos you take may end up being a failure.

For example, to take close-up shots, you must use a macro lens or attach a bellows to use a macro strobe, but you may accidentally fire a general photography strobe or built-in strobe. If you do so, the lens will cast a shadow on the screen because you are close to the subject, resulting in a failed photo.

Additionally, with cameras equipped with an automatic flash function, when taking close-up shots, the flash will fire automatically if the subject is dark or dim, even if the photographer does not intend to fire the flash. If the strobe was used for general photography, the photo would be a failure with a shadow from the lens.

[Means and effects for solving the problem] According to the present invention, in order to avoid the above-mentioned failure, when performing close-up shadowing, strobe light is automatically inhibited or strobe light is not emitted. In other words, when the lens is in the macro lens or macro area, or when a bellows is attached, the camera detects this and prevents the strobe from firing by mistake. This is to warn you not to do so.

[Embodiment] FIG. 1 is a circuit connection diagram showing an embodiment of an electric circuit of a camera with a built-in strobe according to the present invention.

In Figure 1, 1 is the power supply battery VBA in the strobe circuit.
A DC/DC converter boosts T, 2 is a microcomputer for controlling operation, and 3 is an A/D conversion circuit. Reference numeral 4 denotes a photometric element made of a silicon photodiode or the like, which is composed of a plurality of photometric elements and is of a split type so that photometry can be performed by dividing the screen. The output of this photometric element 4 is A/D converted by an A/D conversion circuit 3, and then
According to the signal R7 from the microcomputer 2, it is transmitted to the microcomputer 2 via the pass line BUS.

Reference numeral 5 indicates a lens mount, and the microcomputer 2 inputs a signal P8 from the lens mount 5 to determine whether the lens is a macro lens, is in the macro region, or has a bellows attached. That is,
Signal P when a macro lens, macro area, or bellows is attached.
8 is a high level.

Further, SW is a switch that is turned on in conjunction with pressing down of the camera's release button, and R1 is a pull-up resistor. The microcomputer 2 determines whether the SW is on or off based on the input signal of R3.

MGI is a mechanical member that stops the movement of the shutter front curtain (
Electromagnet MC2 that is energized when releasing the lock (not shown)
is an electromagnet that is energized when a mechanical member (not shown) that locks the shutter rear curtain from running is released. TRI
is a switching transistor for switching the energization of the electromagnet MCI, and TR2 is a switching transistor for switching the energization of the electromagnet MG2. The bases of the transistors TR1 and TR2 are connected to the output port P4 of the microcomputer 2 via base resistors R5 and R6, respectively. Connected to P5.

The input of the converter 1 is connected to a strobe light emitting circuit. Further, TC is a trigger capacitor for starting light emission, one end of this trigger capacitor TC is grounded, the other end is connected to the output of converter 1 via resistor R2, and is connected to thyristor Sl via coil C1.
It is connected to the. The gate of this thyristor SI is connected to the output port P1 of the microcomputer 2, and the microcomputer 2 controls whether the strobe emits light or not.

Also, MC is a main condenser, and XE is a cannon tube. - R3 and R4 are voltage dividing resistors for detecting the charged voltage of the main capacitor Me, and the divided voltage is input to the input port P2 of the microcomputer 2, and the main capacitor MC is sufficiently charged. It communicates whether or not it is in the correct state. TR3 is a switching transistor for supplying power to the strobe light emitting circuit including the converter 1. Its base is connected to the output port PO of the microcomputer 2 via a base resistor R7, and the microcomputer 2 determines whether or not to supply power. controlled.

The operation of the electric circuit configured as shown in FIG. 1 will be explained based on an operation flowchart of the microcomputer 2.

FIG. 2 is a flowchart of one operation of the microcomputer 2. As shown in FIG.

Step S1: When the power supply battery VBAT is installed and the circuit is activated, it is first determined whether the release switch SW is on. If the release switch SW is off, repeat step S1 until the release switch SW is turned on.
When the release switch SW is turned on, the process advances to step S2.

Step S2: Output a high level signal from the output port PO, turn off the switching transistor TR3, and cut off the power supply to the strobe light emitting section.

Step S3: The output of the photometric element 4 is A/D converted by the A/D conversion circuit 3 to obtain photometric data. Based on this photometric data, it is determined whether the scene is dark or backlit.

Step S4 Based on the judgment result in step S3, if the scene is neither dark nor backlit, the platform determines that there is no need to emit the strobe and proceeds to step S12; if the scene is dark or backlit, the process proceeds to step S5. .

Step S5 If the macro lens is not attached, the lens is in macro mode, or the bellows is attached, a high level is input from P8, so the process branches to step 312. , prevent the strobe from firing. If a low level is input from P8, which is not the case in any of the above cases, it is determined that it is necessary to emit light from the strobe, and the process proceeds to step S6.

Step S6: A low level signal is output from the output capo-1-PO, the switching transistor TR3 is turned on, and power supply to the strobe light emitting section is started.

Step S7: The microcomputer 2 determines whether or not the strobe has completed charging by reading the input capo P2.
Since it is set to exceed the input threshold value, when it is input as a high level signal, it is assumed that charging is completed and the process branches to step S8. If charging is not completed, the process returns to step S7 and waits until charging is completed.

Step S8: By outputting a high level signal from the output port P4, the switching transistor TRL is turned on, the electromagnet MCI is energized, the front shutter curtain (not shown) is driven, and exposure is started.

Step S9: By outputting a high level signal from the output port P1, the thyristor SI is turned on, and the charge accumulated in the trigger capacitor TC is discharged through the coil C1. The coil C1 applies a high-voltage induced electromotive force to the outer circumference of the xenon tube XE, thereby causing the xenon tube XE to emit light.

Step S10: Wait until the exposure time ends in order to obtain proper exposure according to the photometric value.

Step Sit By outputting a high level signal from the output port P5, the switching transistor TR2 is turned on, the electromagnet MG2 is energized, the shutter rear curtain (not shown) is run, and the exposure is completed.

Note that in step S4 or step S5, when there is no need for strobe light emission, the process branches to step 312; however, step S12 performs the same operation as step S8, step S13 performs the same operation as step S10, and step S14 performs the same operation as step sti. conduct.

A series of operations related to exposure are performed in steps 312 to S14, but since the thyristor Sl is not turned on, the strobe light is not emitted regardless of whether charging is completed or not.

After exposure, the process proceeds to step 315 regardless of whether the strobe is emitted or not.

Step S15: A motor (not shown) for feeding the film and charging the shutter spring is energized to carry out feeding and charging. after that,
Return to step S1.

In this way, in the camera according to the present invention that has a built-in strobe and has an automatic flash function, the lens may be a macro lens, or
It recognizes when a lens with a macro function is in the macro area or a bellows is attached, and prohibits the built-in flash from firing when taking close-up shots, preventing the built-in flash from creating a shadow on the shooting screen or causing waste. I made it so that it doesn't emit light.

[Other Embodiments] Next, an embodiment of the present invention will be described in a camera that is equipped with a strobe and does not have an automatic flash function.

FIG. 3 is a circuit connection diagram showing this embodiment. Furthermore, the first
Items common to the figures are indicated by the same symbols.

Reference numeral 7 indicates a strobe circuit that is connected to the camera by an actuator, and has a strobe battery that is powered separately from the camera, and a manual strobe SW (switch) that starts charging the strobe.

When the strobe SW is ON, a low (L) level is output to the input port P10 of the CPU 2.

Input port P11 of CPt12 determines whether the strobe is for macro photography or general photography.
It is designed to be distinguished by the signal given to it.

The operation of the electric circuit configured as shown in FIG. 3 will be explained based on the operation flowchart of the microcomputer 2.

FIG. 4 shows the microcomputer 2 in this embodiment.
1 is an operation flowchart of one of the following.

Step S1: When the power supply battery is installed and the circuit is activated, it is first determined whether the release switch SW is on. If release switch SW is off, release switch S
Step S1 is repeated until W is turned on, and when the release switch SW is turned on, the process proceeds to step S2.

Step S2: The output of the photometric element 4 is A/D converted by the A/D conversion circuit 3 to obtain photometric data. Based on this photometric data, the exposure time, aperture (not shown), etc. are determined.

Step S3 If the macro lens is attached, the lens is in macro mode, or the bellows is attached, a high level is input from P8, so the process branches to step S5. When a low level is input from P8, the process branches to step S4.

Step 54: Based on the PTT input, it is determined whether the strobe is for macro photography or general photography. If it is a strobe for general photography, the lens is also for general photography, so the process advances to step S6 and strobe light emission is not prohibited.

If it is a strobe for macro photography, the lens is for general photography, so the process advances to step S12 and the strobe does not emit light.

Step S5 Determine the strobe in the same way as in step S4. If it is a strobe for general photography, the lens is for macro photography, so proceed to step S12 and do not fire the strobe. If it is a strobe for macro photography, the lens Since this is also for macro photography, the process advances to step S6 and strobe light emission is not prohibited.

Step S6: When the strobe SW is not turned on or when the strobe is not attached, the PIO input becomes high level and the strobe cannot fire, so step 1
Proceed to step 2. If the strobe SW is ON1 and the Plo input is at L level, the process advances to step S7 to fire the strobe and take a picture.

Step 37 - Step S15 Exactly the same as the previous example.

The present invention can be easily implemented even in the case of a camera that has a built-in strobe and does not have an automatic flash function, or a camera that is equipped with a strobe and has an automatic flash function. Furthermore, the camera may be equipped with a serial communication function that can also exchange various other information to enable the camera to determine whether the lens or strobe is for macro photography or for general photography.

In addition, if the system does not have a function to prohibit strobe firing when the external strobe is powered on, it may cause noise or
It is also possible to use a structure that warns the photographer with ED flash, etc., and notifies the photographer to turn off the power of the external strobe. [Effects of the Invention] As explained above, if the lens is a macro lens and the camera is in the macro range, When preparing for close-up photography, such as when a bellows is installed or a bellows is attached, the camera should be configured so that it detects this and does not fire the strobe, or
By warning not to fire the strobe, you can eliminate the trouble of taking close-up shots where the lens casts a shadow on the screen due to the strobe firing, making the camera easy to use despite its multi-functions. realizable.

[Brief explanation of the drawing]

FIG. 1 is an electric circuit diagram of a camera according to an embodiment of the present invention, FIG. 2 is a flowchart showing an example of the operation of the circuit shown in FIG. 1, FIG. 3 is an electric circuit diagram of a camera according to another embodiment, and FIG. FIG. 3 is a flowchart showing an example of the operation of the circuit. 1...Converter 2...Microcomputer 3...A/D conversion circuit 4...Photometric element VBAT・
...Power supply battery TR3...Switching transistor MC...Main capacitor XE...Xenon tube SI...Thyristor and 4 others

Claims (1)

[Claims] 1. A close-up photography discrimination means is provided to determine when a macro lens is attached, when the lens is in the macro area with a lens with a macro area, or when a bellows for close-up photography is attached, and the output of the discrimination means determines whether the flashlight is emitted. A camera characterized by activating a means for prohibiting the use of a flash or for warning against emitting a flash.