JP2001228513A - Film unit equipped with lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film unit equipped with a lens capable of always photographing with appropriate exposure in a photographing scene where strobe light is required. SOLUTION: In the film unit equipped with a lens which is provided with a strobe device including a xenon tube Xe, and where an unexposed photographic film is stored, and for photographing by using a photographing mechanism which is operated at a prescribed diaphragm value and a prescribed shutter speed, when the stop value in the photographing mechanism is expressed by F, the shutter speed is expressed by T, the film sensitivity (ISO) of the photographic film is expressed by S, and when the following expressions are defined as for respective apex values; Av=logF2/log2, Tv=log(1/T)/log2, Sv=log(S/100)/ log2, and a reference exposure value = Av+Tv-Sv, the light emission reference value for starting emitting the light from the xenon tube Xe of the strobe device in accordance with the object luminance or ambient luminance is set within the extent of <=(reference exposure value +1) EV and >=(reference exposure value -2.3) EV.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film unit with a lens, and more particularly, to a film unit with a lens which is equipped with a strobe device and which automatically makes the strobe device automatically emit light according to the brightness of a subject or surroundings.

[0002]

2. Description of the Related Art A film unit with a lens, in which a film is pre-loaded in an assembling process, is provided at a low price with a simple operation such that a user does not need to load the film. Also, as shown in FIG. 6, models with a built-in strobe device are widely used, and when it is determined that strobe light emission is necessary, a strobe-type operation member 101 is operated to start strobe charging.

With this operation, as shown in the conventional strobe circuit of FIG. 7, a slide type double switch comprising a main switch SW11 and a light emission stop switch SW12 is turned on, and for example, an AA battery is formed. The DC voltage from the power supply BT is applied to the oscillation transistor Q101 via the resistor R101.
The oscillation transistor Q101 is turned on to start oscillating, and a high AC voltage is induced in the secondary winding of the oscillation transformer TR101.

[0004] The AC voltage output from the oscillation transformer TR101 is rectified by the diode D101 and becomes a DC voltage to charge the main capacitor CM. The resistance R1
The trigger capacitor Ct is also charged via 02.

When the main capacitor Cm and the trigger capacitor Ct are charged and the voltage reaches a predetermined value, it is confirmed that the pilot lamp 102 is energized through the resistor R103 and the shutter release button 103 is pressed. When the shutter blades open, the trigger switch SW13 is turned on when the shutter blades are fully opened.

When the trigger switch SW13 is turned on, the electric charge charged in the trigger capacitor Ct is supplied to the primary winding of the trigger coil TR102, and a high voltage is induced in the secondary winding, and the high voltage causes the arc tube Xe. Is triggered.

As a result, the arc tube Xe housed in the flash unit 104 emits light. When the main capacitor Cm is being charged, the main switch SW11
Is turned off, the oscillation operation of the oscillation transistor Q101 stops.

Since the light emission stop switch SW12 is also turned off at the same time, the discharge path of the trigger capacitor Ct is cut off even if the shutter release button 103 is pressed to turn on the trigger switch SW13, so that the light emission tube Xe does not emit light.

[0009]

However, in the above-mentioned film unit with a lens, the operating member 101 is required.
Is determined by the user based on the luminance of the subject and the like. The flash emission amount of the arc tube Xe is about 2 to 2 for the main subject.
A constant light amount is set in advance so that an appropriate light amount is obtained at 3 m.

For this reason, in practice, underexposed photographs have been taken in the shade during the day when strobe light is required, or when photographing in a bright room or the like.

Accordingly, the present invention provides a film unit with a lens that can reliably operate a strobe device in a photographing scene where strobe light is required and cause a light emitting tube to emit light.

[0012]

According to the first aspect of the present invention,
A film unit equipped with a strobe device including an arc tube and containing an unexposed photographic film, and taking a photograph using a photographing mechanism that operates at a predetermined aperture value and a predetermined shutter speed. the aperture value F, the shutter speed T, the film sensitivity of photographic film (ISO) and S, with Av = logF apex value respectively ² / log2, Tv = lo
g (1 / T) / log2, Sv = log (S / 100)
/ Log2, reference exposure value = Av + Tv−Sv, the emission reference value at which the light emitting tube of the strobe device starts emitting light in accordance with the subject brightness or the peripheral brightness is (reference exposure value + 1) EV or less, Reference exposure value-2.3) EV
It is characterized in that it is set within the above range.

According to a second aspect of the present invention, in the film unit with the lens according to the first aspect, the light emission reference value is set to:
(Reference exposure value +1) EV or less, (reference exposure value -1.
5) It is characterized in that it is set to a range equal to or larger than EV.

According to a third aspect of the present invention, a strobe device including an arc tube is mounted, an unexposed photographic film is stored, and a photograph is taken using a photographing mechanism that operates at a predetermined aperture value and a predetermined shutter speed. In the film unit with a lens to be performed, the upper limit of a light emission reference value at which the light emitting tube of the strobe device starts emitting light is set to (reference exposure value + 1) EV or less according to the subject brightness or the peripheral brightness. It is.

According to a fourth aspect of the present invention, a strobe device including an arc tube is mounted, an unexposed photographic film is stored, and photographing is performed using a photographing mechanism that operates at a predetermined aperture value and a predetermined shutter speed. In the film unit with a lens to be performed, an upper limit of a light emission reference value at which the light emitting tube of the strobe device starts emitting light is set to be equal to or less than a reference exposure value in accordance with subject brightness or peripheral brightness.

According to a fifth aspect of the present invention, a strobe device including an arc tube is mounted, an unexposed photographic film is stored, and a photograph is taken using a photographing mechanism that operates at a predetermined aperture value and a predetermined shutter speed. In the film unit with a lens to be performed, the upper limit of the light emission reference value at which the light emitting tube of the strobe device starts emitting light in accordance with the subject brightness or the peripheral brightness is set to (reference exposure value -1) EV. is there.

According to a sixth aspect of the present invention, a strobe device including an arc tube is mounted, an unexposed photographic film is stored, and a photograph is taken using a photographing mechanism which operates at a predetermined aperture value and a predetermined shutter speed. In the film unit with a lens to be performed, the upper limit of the light emission reference value at which the light emission tube of the strobe device starts emitting light according to the subject brightness or the peripheral brightness is set to (reference exposure value-1.5) EV or less. It is assumed that.

According to a seventh aspect of the present invention, a strobe device including an arc tube is mounted, an unexposed photographic film is stored, and a photograph is taken using a photographing mechanism that operates at a predetermined aperture value and a predetermined shutter speed. In the film unit with a lens to be performed, the lower limit of the emission reference value at which the light emitting tube of the strobe device starts emitting light according to the subject brightness or the peripheral brightness is set to be equal to or more than (reference exposure value-2.3) EV. It is assumed that.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing an appearance of a film unit with a lens according to Embodiment 1 of the present invention when a lens cover is fully closed. FIG. 2 is a view of the film unit with a lens when the lens cover is fully opened. Perspective view showing the appearance of
FIG. 3 is a circuit diagram of a strobe device, and FIG. 4 is a diagram showing numerical examples of an aperture value, a shutter speed, a film sensitivity, and a reference exposure value.

As shown in FIGS. 1 and 2, the lens-equipped film unit according to the first embodiment comprises a front cover 2 and a rear cover 3 made of a synthetic resin. The camera body 4 is covered with a fixed strobe light emitting section 5 constituting a strobe device at the right end of the upper surface of the camera body 4. An unexposed roll film is loaded in the camera body 4 in advance. Have been
The rear cover 3 has no back cover for attaching and detaching the film, and the front cover 2 and the rear cover 3 can be used without using a disassembling tool.
It has a sealed structure that cannot be disassembled.

The camera body 4 is provided with the above-described strobe light emitting section 5, photographing lens 6, and finder window 7 on the front, and a lens cover 8 for covering and protecting the photographing lens 6 outside the photographing lens 6. Are mounted so as to be openable and closable by sliding operations in the left and right directions along the guide rails 9 and 9. A lighting window 10 for taking in external light is provided below the finder window 7.
In FIG. 2, a phototransistor Ph1 as a detecting element 41 and a phototransistor Ph2 as a light receiving element, which will be described later, have an integrated structure.

A shutter release button 11 and a film counter window 12 are provided on the upper surface of the camera body 4.

Further, a dial-type film winding knob 13 and a finder eyepiece window (not shown) are provided on the back of the camera body 4, and a battery chamber (not shown) provided on the inner bottom of the camera body 4. A DC power source B using, for example, an AA dry battery is accommodated therein.

Further, a strobe operation member interlocking with the opening / closing operation of the lens cover 8 is disposed inside the lens cover 8 of the camera body 4.
Main switch SW1 and trigger circuit switch S
W2 is turned on and off. Although the circuit example shown in FIG. 3 has a configuration in which the main switch SW1 and the trigger circuit switch SW2 are separated, a circuit configured with a single contact switch may be used.

The strobe light emitting section 5 contains a xenon tube Xe, which is a light emitting tube constituting a strobe device.

Here, the circuit configuration of the strobe device will be described with reference to FIG.

The strobe device includes a strobe light emitting circuit 30 including an oscillation driving circuit 32 including a DC power supply B, and an arc tube driving circuit 33 for driving the xenon tube Xe based on a driving voltage from the oscillation driving circuit 32. are doing.

The oscillation drive circuit 32 includes a DC power supply B, a main switch SW1 for starting oscillation, and a primary winding W.
1, an oscillation transformer T having a secondary winding W2 and a tertiary winding W3, a collector connected to the primary winding W1 of the oscillation transformer T, and an emitter connected to the negative side of the DC power source B via a main switch SW1. The oscillation transistor TR connected to
A resistor R1 is connected to the base of the oscillating transistor TR and the anode of the DC power source B, and a tertiary winding W3 of the oscillating transformer T is connected.
And a series circuit of a resistor R2 connected to the oscillating transformer T and a light emitting diode DL functioning as a charging indicator lamp.
And a rectifying diode D connected to the secondary winding W2.

Incidentally, a configuration in which a series circuit of the tertiary winding W3, the resistor R2 and the light emitting diode DL is omitted may be adopted.

The arc tube driving circuit 33 has a main capacitor CM for supplying a high voltage for light emission to the xenon tube Xe, and charges the main capacitor CM with an output voltage from the diode D.

The trigger circuit 34 includes a xenon tube Xe
A trigger coil Tc for applying a high voltage to a trigger electrode G provided on the xenon tube Xe to emit light, a trigger capacitor CT for applying a charge to the trigger coil Tc via a Zener diode DT and a resistor R3, and a shutter release. A trigger switch ST for connecting the trigger coil Tc and the trigger capacitor CT when the shutter blade is opened by the release operation of the button 11 is provided. By the trigger circuit 34, the charging voltage of the main capacitor CM is applied between the anode and the cathode.
e is triggered to emit light.

The film unit with a lens according to the first embodiment further includes a phototransistor Ph1 which is a detecting element for detecting a steady light luminance level of a subject, and the oscillation in accordance with the detection result of the luminance level of the phototransistor Ph1. A transistor T as a switching element for controlling ON / OFF of the oscillation transistor TR of the drive circuit 33
R1 and a phototransistor P which is a light receiving element for receiving light reflected from the subject by the light emission of the xenon tube Xe.
h2 and a light emission amount control circuit 50 for controlling the light emission amount of the xenon tube Xe so that the subject is appropriately exposed according to the light amount received by the phototransistor Ph2.

The light emission control circuit 50 includes a resistor R4 connected to a connection end of a phototransistor Ph2, which is a light receiving element connected in parallel with the Zener diode DT, and a capacitor CP.
A transistor TRP having an emitter connected to the anode of the diode D via a resistor R5, and a collector connected to a connection end of the Zener diode DT and the resistor R3; and a main capacitor CM.
And a series circuit of a thyristor S1 connected in parallel and a choke coil Cc for a damper, and the gate of the thyristor S1 is triggered by the transistor TRP.

In FIG. 3, S2 is a connection end between the Zener diode DT and the resistor R3 and the choke coil C.
c, a thyristor for preventing chattering of the trigger circuit switch SW2 having a gate connected to a connection terminal between the trigger capacitor CT and the resistor R3.

In the first embodiment, the aperture value in the photographing mechanism of the camera body 4 is F, the shutter speed is T (sec), and the film sensitivity (IS
O) is defined as S, and each is expressed as an apex value, and Av = log
^{F 2 / log2, Tv = log} (1 / T) / log2,
Sv = log (S / 100) / log2, reference exposure value =
When defined as Av + Tv-Sv, the emission reference value at which the xenon tube Xe of the strobe device starts emitting light according to the subject brightness or the peripheral brightness is (reference exposure value + 1) EV
In the following, the range is set to be equal to or more than (reference exposure value-2.3) EV.

Aperture value F, shutter speed T (se
c), A and B in FIG. 4 show specific numerical examples of the photographic film film sensitivity (ISO) S and the reference exposure value.

An example of setting a specific reference exposure value for the camera body 4 is as follows.

That is, generally, the over side of the film latitude is about +3 EV.

In addition, the maximum brightness of the daytime stationary light, which is generally well taken, is about +12 to +15 EV.
By taking these factors into account and setting the reference exposure value to about +9 to +12 EV, it becomes possible to shoot in the range of film latitude.

Next, various examples of setting the light emission reference value will be described.

In the first embodiment, the light emission reference value at which the xenon tube Xe of the strobe device starts light emission is:
(Reference exposure value +1) EV or less, (reference exposure value -2.
3) The range is equal to or higher than the EV, and the range is set as follows in this range.

(1) The upper limit of the light emission reference value is set to (reference exposure value + 1) EV or less.

Since the variation in the sensitivity and operating characteristics of the phototransistor Ph1 as a detecting element for detecting the steady light luminance level of the object is about +1 EV, the xenon tube Xe uses the phototransistor Ph1 with small variation and the reference exposure. The upper limit of the light emission reference value is set to (reference exposure value + 1) or less so that the light emission operation is performed below the value. The operating characteristics of the phototransistor Ph1 are adjusted by the resistors R6 and R7. In this case, even if the xenon tube Xe is caused to emit light at the reference exposure value or more and (reference exposure value + 1) or less, it is possible to obtain a photographing condition without a problem as a photograph.

(2) The upper limit of the light emission reference value is set to be equal to or less than the reference exposure value.

When the luminance of the object falls below the reference exposure value, the photograph tends to be underexposed. Therefore, the upper limit of the emission reference value is set to be equal to or less than the reference exposure value in order to surely emit light from the xenon tube Xe.

(3) The upper limit of the light emission reference value is set to (reference exposure value-1) EV or less.

As a result of actually taking and investigating a photograph, it was found that a photograph was taken without deteriorating the atmosphere of the photograph (reference exposure value -1) E
It has been found that it is desirable to start the light emission of the xenon tube Xe at about V, so the upper limit of the light emission reference value is set to (reference exposure value-
1) The following are set.

(4) The upper limit of the light emission reference value is set to (reference exposure value-1.5) EV or less.

Since the latitude on the under side of the photographic film which can be corrected without any problem at the time of photographic printing is about -1.5 EV, the upper limit of the luminescence reference value is set to (reference exposure value-
1.5) The following is set.

(5) The lower limit of the light emission reference value is set to be equal to or more than (reference exposure value-2.3) EV.

Since the lower limit of the latitude on the under side of the photographic film is -2.3 EV, the lower limit of the light emission reference value is set so that light emission can be started at a higher value (reference exposure value -2.3).
It is set to EV or more.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to FIG.

The circuit configuration of the strobe device of the film unit with a lens according to the second embodiment shown in FIG.
Are substantially the same as those in the first embodiment shown in FIG. 1, those having the same functions are denoted by the same reference numerals, and detailed description thereof will be omitted.

The strobe device according to the second embodiment includes the phototransistor Ph1 and the transistor TR1 according to the first embodiment.
Instead, as shown in FIG. 5, a CdS element 61, which is a detection element for detecting the steady light luminance level of the subject, and the trigger circuit 34 is turned on in accordance with the detection result of the luminance level.
Thyristor S3, a switching element that performs off control
It is a feature that is used. Other configurations are the same as those shown in FIG.

That is, a series circuit of the CdS element 61 and the resistor R8 is connected in parallel with the trigger capacitor CT.
The gate of the thyristor S3 is connected to the connection end of the CdS element 61 and the resistor R8, the anode of the thyristor S3 is connected to the trigger switch ST, and the cathode of the thyristor S3 is connected to the connection end of the trigger capacitor CT and the resistor R3. are doing.

In the second embodiment having such a configuration, when the luminance of the stationary light detected by the CdS element 61 as the detecting element is higher than a predetermined luminance, the voltage applied to the CdS element 61 is Low, and therefore thyristor S3
Gate is not triggered, thyristor S3 remains off, and as a result, shutter release button 1
Even if 1 is pressed to activate the shutter and turn on the trigger switch ST, the trigger circuit 34 does not operate and the xenon tube Xe does not emit light. That is, in this case, photographing is performed without flash emission.

On the other hand, when the luminance of the stationary light detected by the CdS element 61, which is the detecting element, is lower than a predetermined luminance, the voltage applied to the resistor R8 connected to the CdS element 61 becomes high. When the trigger is applied to the gate of the thyristor S3, the thyristor S3 is turned on. As a result, when the shutter release button 11 is pressed to operate the shutter and the trigger switch ST is turned on, the trigger circuit 34 operates and the xenon tube Xe is turned on. Emits light. That is, in this case, photographing by flash emission is performed.

As described above, also in the second embodiment, the automatic light emission control of the xenon tube Xe is executed in accordance with the degree of the luminance of the stationary light detected by the CdS element 61 as the detecting element.

Also in the second embodiment, the emission reference value at which the xenon tube Xe of the strobe device starts emitting light is set to (reference exposure value + 1) EV or less and (reference exposure value−
2.3) Various modes are set within the range of EV or more as described in (1) to (5) in the first embodiment.

In particular, as in the case of the first embodiment, C is a detecting element for detecting the steady light luminance level of the subject.
Since the variation in the sensitivity and the operation characteristics of dS61 is about +1 EV, the upper limit of the emission reference value is set to (reference exposure value + reference value) so that the xenon tube Xe performs the emission operation at the reference exposure value or less.
1) The following are set. The operating characteristics of the CdS 61 are adjusted by the value of the element resistance and the selection of the resistor R8.

[0062]

According to the present invention, as described above, the emission reference value at which the xenon tube Xe of the strobe device starts emitting light is set to (reference exposure value + 1) EV or less and (reference exposure value-
2.3) By setting various values within the range of EV or more,
It is possible to provide a lens-equipped film unit that can always perform photographing with appropriate exposure according to the subject luminance and the peripheral luminance.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an appearance of a film unit with a lens according to a first embodiment of the present invention when a lens cover is fully closed.

FIG. 2 is a perspective view illustrating an appearance of the film unit with a lens according to the first embodiment when a lens cover is fully opened.

FIG. 3 is a circuit diagram of the strobe device according to the first embodiment.

FIG. 4 is a diagram showing a numerical example of a reference exposure value according to the first embodiment.

FIG. 5 is a circuit diagram of a strobe device according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing the appearance of a conventional film unit with a lens.

FIG. 7 is a circuit diagram of a conventional flash device of a film unit with a lens.

[Explanation of symbols]

 4 Camera body 11 Shutter release button 30 Strobe light emission circuit 32 Oscillation drive circuit 33 Arc tube drive circuit 34 Trigger circuit 50 Light emission amount control circuit 61 CdS element B DC power supply TR Oscillation transistor T Oscillation transformer Xe Xenon tube SW1 Main switch SW2 Trigger circuit switch CM Main capacitor Ph1 Phototransistor

Claims (7)

[Claims] 1. A strobe device including an arc tube is mounted, and an unexposed photographic film is stored therein.
In a film unit with a lens for taking a photograph using a photographing mechanism that operates at a predetermined shutter speed, an aperture value of the photographing mechanism is F, a shutter speed is T, and a film sensitivity (ISO) of the photographic film is S. Av = logF ² / lo in Apex value
g2, Tv = log (1 / T) / log2, Sv = lo
g (S / 100) / log2, reference exposure value = Av + Tv
When defined as -Sv, the emission reference value at which the light emitting tube of the strobe device starts emitting light in accordance with the subject brightness or the peripheral brightness is equal to or less than (reference exposure value + 1) EV and (reference exposure value-2.3). A film unit with a lens, wherein the film unit is set to a range equal to or higher than EV. 2. An emission reference value is defined as (reference exposure value + 1) EV.
2. The film unit with a lens according to claim 1, wherein the value is set to be equal to or more than (reference exposure value-1.5) EV. 3. A strobe device including an arc tube is mounted, and an unexposed photographic film is stored therein.
In a film unit with a lens for photographing using a photographing mechanism that operates at a predetermined shutter speed, the upper limit of a light emission reference value at which the light emitting tube of the strobe device starts emitting light according to the subject brightness or the peripheral brightness is set to a reference exposure value. A film unit with a lens, characterized in that the value is set to a value +1 EV or less. 4. A strobe device including an arc tube is mounted, and an unexposed photographic film is stored therein.
In a film unit with a lens for photographing using a photographing mechanism that operates at a predetermined shutter speed, the upper limit of a light emission reference value at which the light emitting tube of the strobe device starts emitting light according to the subject brightness or the peripheral brightness is set to a reference exposure value. A film unit with a lens, characterized in that it is set below the value. 5. A strobe device including an arc tube is mounted, and an unexposed photographic film is stored therein.
In a film unit with a lens for photographing using a photographing mechanism that operates at a predetermined shutter speed, the upper limit of the light emission reference value at which the flash tube of the strobe device starts emitting light according to the subject brightness or the peripheral brightness is set to (reference exposure). Value-1) A film unit with a lens, which is set to EV. 6. A strobe device including an arc tube is mounted, and an unexposed photographic film is stored therein.
In a film unit with a lens that performs photographing using a photographing mechanism that operates at a predetermined shutter speed, the upper limit of the light emission reference value at which the light emitting tube of the strobe device starts emitting light according to the subject brightness or the peripheral brightness is set to (standard Exposure value-1.5) A film unit with a lens, which is set to an EV or less. 7. A strobe device including an arc tube is mounted, and an unexposed photographic film is stored therein.
In a film unit with a lens for taking a photograph using a photographing mechanism that operates at a predetermined shutter speed, the lower limit of the light emission reference value at which the light emitting tube of the strobe device starts emitting light in accordance with the subject luminance or the peripheral luminance is defined as (reference Exposure value-2.3) A film unit with a lens, which is set to an EV or more.