JP2004069915A - Lens-fitted photographic film unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly flash a strobe by changing over a diaphragm. <P>SOLUTION: A first main capacitor 61 and a second main capacitor 62 are connected to each other in parallel, and a light amount switch 52 is connected to one end of the second main capacitor 62. The light amount switch 52 is turned on during small diaphragming to allow discharge of the second main capacitor 62, and turned off during large diaphragming to prohibit discharge of the second main capacitor 62. A diode 63 is connected in parallel to the light amount switch 52, and charge of the second main capacitor 62 is allowed regardless of turning on/off of the light amount switch 52. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lens-fitted photo film unit incorporating a strobe device.
[0002]
[Prior art]
Various types of lens-equipped film units pre-loaded with unexposed photographic film are available. Such a lens-fitted photo film unit is widely used because it has a simple and inexpensive photographing mechanism such as a shutter mechanism and a film winding mechanism and is easy to use. ing.
[0003]
Some of these lens-equipped film units have a built-in strobe device so that they can take pictures even in dark places such as indoors and at night. In addition, there are switches that change the aperture value so that good shooting is possible from shooting in dark places to shooting in bright places, and others that change the amount of strobe light in conjunction with this change in aperture value are also known. (Japanese Patent Laid-Open No. 2001-337364).
[0004]
In the strobe device described in Japanese Patent Application Laid-Open No. 2001-337364, the light visor is inserted into and removed from the front surface of the strobe light emitting unit and the capacity of the main capacitor is increased or decreased in conjunction with the switching of the aperture value. The flash output is adjusted. This circuit for increasing or decreasing the capacity of the main capacitor has a configuration in which a switch that is turned on / off according to the aperture value is connected to one end of one of the two main capacitors.
[0005]
[Problems to be solved by the invention]
By the way, in the method of inserting / removing the light visor, there is a drawback that the strobe light irradiation pattern is changed because the strobe light is reduced by hiding a part of the strobe light emitting portion with the light visor.
[0006]
In addition, in the strobe device that increases or decreases the capacity of the main capacitor as described above, after confirming that the preparation for strobe emission is complete, that is, the main capacitor is charged to a voltage higher than the strobe light, the aperture can be switched to shoot. If you perform flash, the flash may not fire normally. This is because when the switch connected to one main capacitor is off, only the other main capacitor is charged, but one main capacitor is not charged and is charged when the switch is turned on by changing the aperture. This is because charge flows from the main capacitor to the uncharged main capacitor, the charging voltage is greatly reduced, and the voltage of the main capacitor becomes equal to or lower than the light emission possible voltage.
[0007]
In order to prevent the inconvenience as described above, it is only necessary to first select a diaphragm so that both main capacitors are charged and confirm the completion of charging. However, there is a problem that the operation and confirmation work become complicated. In addition, when the subject brightness is measured in response to the pressing operation of the release button and the aperture is automatically switched based on the measurement result, shooting is performed immediately after the aperture is switched. This circuit configuration cannot be adopted.
[0008]
The present invention has been made in consideration of the above circumstances, and provides a lens-fitted film unit that can perform normal strobe light emission even when the aperture is switched, and can simplify the operation and confirmation work. With the goal.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, in the film unit with a lens according to claim 1, a plurality of main capacitors connected in parallel to each other so as to be charged by a charging circuit and discharged by a strobe discharge tube, A light amount switch that is connected to one end of at least one of the main capacitors and that is turned on / off in conjunction with the switching of the aperture, and that the main capacitor is allowed to be charged when the light amount switch is turned off. The strobe device is provided with a diode connected in parallel to the light amount switch.
[0010]
In the film unit with a lens according to claim 2, the film sensitivity of the photographic film loaded in advance is ISO 1600 or more.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the appearance of a lens-fitted photo film unit embodying the present invention. The film unit with a lens is composed of a unit main body 2 and an exterior body 3 that partially covers the unit main body 2. The unit main body 2 includes a shutter mechanism, an aperture switching mechanism, a film feeding mechanism, a strobe device, and the like. Various shooting mechanisms are built-in.
[0012]
The unit main body 2 is loaded with a film cartridge comprising a cartridge for storing an unexposed photographic film and a photographed photographic film. Photographic films having various film sensitivities can be used, but ISO 1600 or higher is preferable in order to reduce the electrostatic capacity of a main capacitor of a strobe device to be described later and to reduce the size.
[0013]
On the front surface of the unit main body 2, a photographing lens 4, an object-side window 5 a of the finder 5, a mode selection member 8, a strobe operating member 9, and a strobe light emitting unit 10 are provided. Further, on the upper surface of the unit main body 2, a release button 11, a counter window 12 for displaying the number of remaining frames that can be photographed, and a charging completion display window 13 for displaying the completion of strobe light emission are provided.
[0014]
Further, on the back surface, a winding knob 14 that is rotated every time one frame is shot is exposed, and an eyepiece side window (not shown) of the finder 5 is provided at a position facing the objective side window 5a. The exterior body 3 is affixed to the central portion of the unit main body 2 and exposes the taking lens 4, the viewfinder 5, the counter window 12, and the like from the openings provided in the respective portions.
[0015]
The mode selection member 8 is for selecting one of a normal mode and a night view mode, which will be described later, as a photographing mode, and is slid upward from the normal mode position shown in FIG. 1 and the normal mode position. It is slidable between the night view mode position. The strobe operating member 9 is used to select whether to turn on or off strobe light emission during shooting. Between the off position shown in FIG. 1 and the on position slid upward from the off position. It can be slid freely.
[0016]
The strobe operating member 9 is slid to the on position in conjunction with the mode selection member 8 being slid to the night view mode position, and the mode selecting member 8 is slid to the off position. In conjunction with, it is slid to the normal mode position. When the normal mode is selected, the strobe operating member 9 can be set to either the on position or the off position.
[0017]
The normal mode is a mode corresponding to photographing in a bright place such as outdoors during the day. Also, in the normal mode, if the strobe operation member 9 is turned on and the strobe light is turned on, a main subject with a shooting distance of about 2.5 m, for example, is photographed with a strobe light at an almost appropriate exposure amount in a relatively bright room. In addition, the background can be photographed with moderate brightness. In this normal mode, a relatively small first aperture and a small aperture with a small aperture diameter are used regardless of whether or not strobe light is emitted.
[0018]
The night view mode is suitable for dark indoors and night outdoors, such as wedding reception halls. For example, a main subject with a shooting distance of about 3m can be taken with a strobe light at an appropriate exposure, and a dark background can be used. It is a mode that can shoot with high brightness. In the night view mode, the second shutter time slower than the first shutter time and the large aperture having a larger aperture diameter than the small aperture are used for photographing. In this night view mode, the flash is forcibly emitted. As described above, the strobe operation member 9 is set to the ON position in conjunction with the mode selection member 8, so that strobe light emission is always performed.
[0019]
As shown in FIG. 2, a shutter opening 20a is formed in front of a dark box 20 that shields light between the photographing lens 4 and the photographic film, and a shutter blade 22 that constitutes a shutter mechanism 21 in front thereof, and a lens unit. 23 are arranged. The photographing lens 4 has a two-lens configuration including a front group lens 4a and a rear group lens 4b.
[0020]
The shutter blade 22 is rotatable between a closed position in which the shutter opening 20a is covered by the blade portion 22a and a terminal position further rotated through a fully opened position retracted from the front surface of the shutter opening 20a. It is assembled to. The shutter blade 22 is urged toward the closed position by the return spring 24, and is normally in the closed position and closes the shutter opening 20a.
[0021]
A rotation restricting lever 25 as a shutter second time switching means is rotatably mounted on the front surface of the dark box 21. The rotation restricting lever 25 has a restricting piece 25a at one end and a pin 25b at the other end. The rotation restricting lever 25 is rotatable between a retracted position where the restricting piece 25a is retracted from the rotation trajectory of the shutter blade 22 and a restricting position entering the rotation trajectory between the fully open position and the end position. It has become.
[0022]
The slide plate 27 in which the mode selection member 8 is integrally formed is slidable in the vertical direction, and an engaging portion 27a is formed on a side portion thereof. The pin 25b is engaged with the engaging portion 27a. As a result, the rotation restricting lever 25 is in the restricting position when the mode selection member 8 is in the normal mode position, and is in the retracted position when in the night view mode position.
[0023]
The shutter mechanism 21 operates in response to a pressing operation of the release button 11. When the shutter mechanism 21 is operated, a shutter drive lever (not shown) which is a part of the shutter mechanism 21 moves at high speed from the charge position toward the release position. During this movement, the contact portion 22 b of the shutter blade 22 is kicked by the shutter drive lever, and the shutter blade 22 rotates toward the end position against the urging force of the return spring 24. The shutter driving lever is set at the charging position in conjunction with the feeding of one frame of the photographic film.
[0024]
When the mode selection member 8 is in the night view mode position, the rotation restricting lever 25 is in the retracted position, so that the shutter blade 22 returns to the closed position by the urging force of the return spring 24 after rotating to the end position. When the mode selection member 8 is in the normal mode position, the rotation restricting lever 25 is in the restricting position. Therefore, the shutter blade 22 abuts against the restricting piece 25 a before reaching the end position and is closed by the urging force of the return spring 24. Return to position. In this way, when the normal mode is selected, the shutter blade 22 operating angle (rotation angle) is reduced to a relatively fast first shutter time, and when the night view mode is selected, the shutter blade 22 is operated. By increasing the angle, a relatively slow second shutter speed is obtained.
[0025]
The lens unit 23 is disposed on the front surface of the dark box 20 so as to sandwich the shutter blade 22 between the lens unit 23 and the dark box 20. The lens unit 23 includes a photographic lens 4, a base 30, a fixed diaphragm plate 31, a spacer 32, a movable diaphragm plate 34 as a diaphragm switching means, and a lens holder 35. Each of these members is inserted into a lens holder 30a formed on the base 30 in this order of the rear group lens 4b, the fixed diaphragm plate 31, the spacer 32, and the front group lens 4a, and is fixed by the lens holder 35.
[0026]
The fixed aperture plate 31 has a large aperture 31a as a large aperture. The spacer 32 secures a space for inserting and removing the tip of the movable diaphragm plate 34 between the fixed diaphragm plate 31 and the front group lens 4a. The movable diaphragm plate 34 is formed with a small diaphragm opening 34a having a smaller diameter than the large diaphragm opening 31a as a small diaphragm at the tip thereof.
[0027]
A movable diaphragm plate 34 having a small aperture 34 a is attached to a shaft 30 c formed on the front surface of the base 30, an insertion position where the small aperture 34 a is arranged on the optical axis of the photographing lens 4, and photographing. The lens 4 is rotatable between a retracted position retracted from the optical axis of the lens 4. In the movable diaphragm plate 34, a pin 27 b provided on the front surface of the slide plate 27 is engaged with a long hole 34 b provided in the rear end portion. Accordingly, the movable diaphragm plate 34 is rotated in conjunction with the sliding movement of the slide plate 27, and is rotated to the insertion position when the mode selection member 8 is set to the normal mode position, and is set to the night view mode position. And rotated to the retracted position.
[0028]
With this configuration, when the night scene mode is selected, the movable diaphragm plate 34 is in the retracted position, and the small aperture opening 34a is retracted from the optical axis of the photographic lens 4, so that the large fixed on the optical axis. The image is taken with a large aperture using the aperture 31a. Further, when the normal mode is selected, the movable diaphragm plate 34 is in the insertion position, and the small aperture 34a is inserted on the optical axis of the photographing lens 4. Therefore, photographing with the small aperture using the small aperture 34a is performed. Become.
[0029]
A strobe operating member 9 is integrally formed on the strobe slide plate 44. The strobe slide plate 44 is slid up and down by a slide operation of the strobe operation member 9. The strobe operating member 9 protrudes from the front surface of the strobe slide plate 44 and is disposed on the movement locus of the interlocking portion 27 c that protrudes to the side of the slide plate 27. Thus, when the mode selection member 8 is slid to the night view mode position, the strobe operation member 9 is pushed up to the on position by the interlocking portion 27c. When the strobe operating member 9 is slid from the on position to the off position, the mode selection member 8 is pushed down to the normal mode position.
[0030]
The strobe switch 50 is turned on / off in conjunction with the slide of the strobe slide plate 44. The strobe switch 50 serves both as a charge switch and a light emission selection switch for selecting whether or not to emit strobe light. When the strobe operating member 9 is set to the on position, the strobe switch 50 is turned on, charging for strobe light emission is performed, and strobe light emission is permitted. When the strobe operating member 9 is set to the off position, the strobe switch 50 is turned off, and strobe light emission is prohibited regardless of whether or not charging is performed.
[0031]
The sync switch 51 is turned on when the shutter blade 22 reaches the fully open position. Strobe light is emitted when the sync switch 51 is turned on.
[0032]
The light amount switch 52 is for switching the amount of strobe light emission according to the aperture at the time of shooting, and is turned on / off in conjunction with the slide of the slide plate 27. The light amount switch 52 is turned on when the mode selection member 8 is in the normal mode position, and is turned off when the mode selection member 8 is in the night view mode position. When the light amount switch 52 is turned off, the amount of flash emission is smaller than when it is turned on, and the main subject is prevented from being overexposed by the strobe light when shooting with a large aperture.
[0033]
FIG. 3 shows a circuit of a strobe device mounted on the lens-fitted photo film unit. The voltage output from the battery 55 is boosted to a high voltage, for example, 300 V by the charging circuit 56, and is output between the output terminals 56a and 56b. The output voltage is output in a direction in which the potential on the output end 56a side increases.
[0034]
The charging circuit 56 includes an oscillation transistor 57, an oscillation transformer 58, a rectifier diode 59, and the like. The battery 55 is used as a power source to generate high voltage alternating current by the oscillation transistor 57 and the oscillation transformer 58, and the alternating current is used for rectification. Rectified by the diode 59 and output. The charging circuit 56 operates when the strobe switch 50 is on and stops when it is off. The configuration of the charging circuit 56 shown in FIG. 3 is an example, and other circuit configurations may be used.
[0035]
As the strobe switch 50, a three-contact type is used, and also serves as a charge switch and a light emission selection switch as described above. When the strobe switch 50 is turned on, the charging circuit 56 is activated due to the base current flowing through the oscillation transistor 57, and the trigger capacitor 60 is charged by the charging circuit 56 and the trigger capacitor 60 is turned on in response to the synchronization switch 51 being turned on. Discharge is allowed. When the strobe switch 50 is turned off, the base current does not flow to the oscillation transistor 57, so that the charging circuit 56 is stopped and the discharge circuit of the trigger capacitor 60 is opened, so that strobe light emission is prohibited.
[0036]
A first main capacitor 61 is connected between the output terminals 56a and 56b, and the first main capacitor 61 is charged with a current flowing in a direction from the output terminal 56a toward the output terminal 56b when the charging circuit 56 is operated. . A light amount switch 52 and a second capacitor 62 connected in series are connected between the output terminals 56 a and 56 b, and a diode 63 is connected in parallel to the light amount switch 52. That is, the first main capacitor 61 and the second capacitor 62 are connected in parallel, the light amount switch 52 is connected to one end of the second capacitor 62, and the diode 63 is connected to the light amount switch 52 in parallel.
[0037]
The diode 63 is connected in such a direction that the current from the charging circuit 56 flows through the second main capacitor 62. In this example, the diode 63 is connected in such a direction that its anode is connected to the output terminal 56a.
[0038]
By connecting the diode 63 in parallel to the light quantity switch 52 as described above, the second main capacitor 62 is charged together with the first main capacitor 61 regardless of whether the light quantity switch 52 is on or off during charging, and the light quantity switch 52 is turned on. Selection of whether both the first and second main capacitors 61 and 62 are discharged by turning off or only the first main capacitor 61 is discharged is enabled.
[0039]
The strobe discharge tube 64 is connected in parallel to each of the first main capacitor 61 and the series circuit of the diode 63 and the second capacitor 62. When a trigger voltage is applied through the trigger electrode 64a, the strobe discharge tube 64 discharges the charges of the first and second main capacitors 61 and 62 and emits strobe light. When the light amount switch 52 is on during the strobe light emission, both the first main capacitor 61 and the second main capacitor 62 are discharged. When the light amount switch 52 is off, only the first main capacitor 61 is discharged. Discharges and strobe light is emitted. Thereby, when the light amount switch 52 is off (night scene mode), the flash emission amount is made smaller than when the light amount switch 52 is on (normal mode).
[0040]
The trigger capacitor 60 is charged by the charging circuit 56 when the strobe switch 50 is on, and is discharged when the synchro switch 51 is on while the strobe switch 50 is on, and the discharge current flows to the primary side of the trigger coil 65. . When a discharge current flows on the primary side, the trigger coil 65 generates a trigger voltage on the secondary side and applies it to the strobe discharge tube 64 via the trigger electrode 64a. When the strobe switch 50 is off, the trigger capacitor 60 is not discharged even when the synchro switch 51 is turned on. Therefore, the trigger voltage is not applied to the strobe discharge tube 64, so that no strobe light is emitted.
[0041]
The aperture value for each of the small and large apertures, the first and second shutter speeds, and the flash output in the normal mote and night scene modes depend on the assumed shooting distance to the main subject and the intensity of available light. Based on the film sensitivity of the photographic film to be used. In this example, the film sensitivity of the photographic film is ISO 1600, the aperture value of the small aperture is F14, the aperture value of the large aperture is F5.6, the first shutter time is 1/140 (sec), and the second shutter time is 1. / 45 (sec), the flash emission amount (GNo.) Is 8.8 (ISO 100 · m) in the normal mode and 4.5 (ISO 100 · m) in the night view mode. The focal length of the photographic lens 4 is 32 mm.
[0042]
The capacitances of the first and second main capacitors 61 and 62 are determined according to the guide numbers in the normal mode and the night view mode, and the charging voltage. In this example, the first main capacitor 61 is 25 μF, and the second main capacitor 62 is 70 μF. Note that at least one of the main capacitors may be a leadless type and may be surface-mounted on the circuit board of the strobe device. Use of the leadless type main capacitor in this way is advantageous in reducing the size of the strobe device and the lens-fitted photo film unit.
[0043]
The light emitting diode 67 is connected to the oscillation transformer 58. The light emitting diode 67 is lit using the fact that the voltage between the terminals of the coil to which the light emitting diode 67 is connected changes according to the charging voltage of the first main capacitor 61 connected to the secondary side of the oscillation transformer 58. Is controlled, and lights up when the first main capacitor 61 reaches a predetermined specified charging voltage during the operation of the charging circuit 56. In this example, the specified charging voltage is set to 250 V at which strobe light emission is possible. Light from the light emitting diode 67 is guided to the charging completion display window 13. As a result, it can be confirmed that strobe light emission is enabled through the charging completion display window 13. At the time of full charge, the first and second main capacitors 61 and 62 are charged to about 360V.
[0044]
In this circuit configuration, the charging voltage V1 of the first main capacitor 61 is equal to or lower than the charging voltage V2 of the second main capacitor 62 (V1 ≦ V2). Therefore, when the first main capacitor 61 is 250 V or higher and the light emitting diode 67 is lit, the second main capacitor 62 is also charged to 250 V or higher.
[0045]
Next, the operation of the above configuration will be described. When photographing, the photographer rotates the winding knob 14 to wind up the photographic film by one frame. Shutter charging is performed in conjunction with the film winding. Further, the mode operation member 8 is operated according to the shooting scene to select the normal mode or the night view mode.
[0046]
For example, when the normal mode is selected, the mode operation member 8 is slid downward to be set to the normal mode position, and then the strobe operation member 9 is operated to select on / off of the strobe light emission. When the mode operation member 8 is set to the night view mode position and the flash is not emitted at the time of shooting, the strobe operation member 9 set to the on position is slid to the off position. The mode operation member 8 may be set at the normal mode position.
[0047]
As described above, when the mode operation member 8 is set at the normal mode position, the rotation restricting lever 25 is rotated and held at the restricting position in conjunction with the sliding movement of the slide plate 27, and the restricting piece 25a is held by the shutter blades 22. It will be in the state which entered on the rotation locus of. Further, the movable diaphragm plate 34 is rotated and held at the insertion position. Further, the light amount switch 52 is turned on.
[0048]
If the strobe operating member 9 is set to the on position, the strobe switch 50 is turned on. When the strobe switch 50 is turned on, the charging circuit 56 starts operating and the first main capacitor 61 is charged, and the current from the charging circuit 56 is supplied to the second main capacitor via the light amount switch 52 that is turned on. Since the current flows to 62, the second main capacitor 62 is also charged.
[0049]
Thus, when the normal mode is selected, the light amount switch 52 is on, so that the charging voltages of the first main capacitor 61 and the second main capacitor 62 are kept at the same voltage. Even when the charging voltages of the first main capacitor 61 and the second main capacitor 62 are different, the respective charging voltages become the same when the light amount switch 52 is turned on.
[0050]
When the first and second main capacitors 61 and 62 reach the specified charging voltage and the strobe light can be emitted, the light emitting diode 67 is turned on. Thus, the photographer can confirm through the charging completion display window 13 that preparation for flash photography has been completed.
[0051]
The framing is determined by looking through the finder 5 and the release button 11 is pressed to take a picture. When the release button 11 is pressed, the shutter mechanism 21 is activated. Thereby, the shutter blade 22 is kicked by the shutter drive lever and starts to rotate from the closed position to the end position. Since the restricting piece 25a of the rotation restricting lever 25 has entered the rotation locus of the shutter blade 22, the shutter blade 22 that has started to rotate toward the end position has not yet reached the end position after fully opening the shutter opening 20a. In contact with the regulating piece 25a, the urging force of the return spring 24 starts to rotate toward the closed position. Thereby, the opening / closing operation | movement of the shutter blade | wing 22 is performed in the 1st shutter time.
[0052]
Further, at the moment when the shutter blade 22 reaches the fully open position where the shutter opening 20a is fully opened, the synchro switch 51 is turned on. Therefore, when the strobe operating member 9 is in the on position, when the sync switch 51 is turned on, a trigger voltage is applied to the strobe discharge tube 55 and strobe light emission is performed. The strobe light emitted from the strobe discharge tube 55 is emitted from the strobe light emitting unit 10 toward the subject. When the strobe operating member 9 is in the off position, the trigger capacitor 60 is not discharged, so that strobe light emission is not performed.
[0053]
The strobe light emission in the normal mode is performed by discharging the first main capacitor 61 through the strobe discharge tube 64 and simultaneously discharging the second main capacitor 62 because the light amount switch 52 is turned on. Thereby, GNo. Strobe light emission is performed at a strobe light emission amount equivalent to 8.8 (ISO 100 · m).
[0054]
While the shutter blade 22 is being opened and closed during the first shutter time, light from the subject incident on the photographic lens 4 exposes the photographic film through the small aperture opening 34a and the large aperture opening 31a. In this case, the amount of light is limited by the small aperture 34a. Therefore, shooting using a small aperture and a relatively fast first shutter speed is performed. Since the aperture value of the small aperture is F14 and the film sensitivity is ISO 1600, GNo. An appropriate exposure amount can be obtained for a subject of about 2.5 m with a strobe emission amount equivalent to 8.8 (ISO 100 · m).
[0055]
When strobe light emission is performed as described above, the light-emitting diode 67 is turned off because the charging voltage V1 of the first main capacitor 61 decreases to several tens of volts. At this time, the charging voltage V2 of the second main capacitor 62 is also the same as that of the first main capacitor 61.
[0056]
If the strobe operating member 9 is set to the on position and the mode operating member 8 is set to the normal mode position, the first main capacitor 61 and the second main capacitor 62 are charged while maintaining the same charging voltage immediately after the strobe light emission, and the specified charging voltage. The light emitting diode 67 is turned on when the value reaches.
[0057]
On the other hand, when shooting a dark subject such as a night view, or when shooting a main subject such as a person against a night view, the main subject such as a person is reproduced while reproducing the background at an appropriate density in a dark room. When shooting, the mode selection member 8 is moved from the normal mode position to the night view mode position to select the night view mode.
[0058]
When the mode selection member 8 is set to the night view mode position, the interlocking unit 27c pushes up the strobe operation member 9 to the ON position. When the night scene mode is selected by operating the mode selection member 8 in this manner, the flash is automatically activated so that shooting can be performed easily and shooting failures can be reduced.
[0059]
When the mode selection member 8 is set to the night view mode position, the rotation restricting lever 25 is rotated and held at the retracted position, and the movable diaphragm plate 34 is rotated and held at the retracted position. Further, when the mode selection member 8 is set to the night view mode position, the light amount switch 52 is turned off. Further, in conjunction with the strobe operation member 9 being turned on, the strobe switch 56 is turned on, and charging of the first main capacitor 61 and the second main capacitor 62 by the charging circuit 56 is started. At this time, the second main capacitor 62 is charged with a current flowing through the diode 63.
[0060]
When the normal mode is switched to the night view mode, the light amount switch 52 is turned from on to off. When the light amount switch 52 is on, the first main capacitor 61 and the second main capacitor 62 are at the same charging voltage, so the first main capacitor 61 and the second main capacitor are also immediately after the light amount switch 52 is turned off. 62 is kept at the same charging voltage.
[0061]
When charging progresses and the first main capacitor 61 reaches a specified charging voltage, the light emitting diode 67 is turned on. The charging voltages V1 and V2 of the first and second main capacitors 61 and 62 immediately after the light amount switch 52 is turned off are the same, and when the light emitting diode 67 is lit, the second main capacitor 62 is the first main capacitor 62. The same specified charging voltage as that of the capacitor 61 or higher is reached. If the charging voltages V1 and V2 of the first and second main capacitors 61 and 62 are the same, strictly speaking, when a current flows through the diode 63, the second main capacitor is equivalent to the voltage drop at the diode 63. The charging voltage V2 of the capacitor 62 is lower than the charging voltage V1 of the first main capacitor 61, but its magnitude is negligible.
[0062]
After each main capacitor 61, 62 reaches the specified charging voltage, the charging voltages V1, V2 rise and finally become fully charged.
[0063]
When the release button 11 is pressed, the shutter mechanism 21 is operated and the shutter blade 22 is opened and closed. In this night view mode, since the rotation restricting lever 25 is rotated to the retracted position, the shutter blade 22 is rotated from the closed position to the end position and then returned to the closed position by the urging force of the return spring 24. At the moment when the shutter blade 22 reaches the fully open position, the sync switch 51 is turned on and strobe light emission is performed. At this time, since the light amount switch 52 is turned off, only the first main capacitor 61 is discharged and strobe light emission is performed. In this way, the flash photography is performed under the large aperture and the second shutter speed slower than that in the normal mode.
[0064]
As described above, since shooting is performed in the night view mode, the main subject of about 3 m is appropriately exposed by the strobe light. For a long-distance subject in which the strobe light is not effective, the second shutter speed is slow and the opening is large. Shooting with no problem in practice can be performed with a large aperture opening.
[0065]
In strobe light emission in the night view mode, only the first main capacitor 61 is discharged as described above, and the charge voltage V1 is reduced to several tens of volts, so that the light emitting diode 67 is turned off. Further, since the second main capacitor 62 is not discharged, the charging voltage V2 is equal to or higher than the specified charging voltage. Therefore, if the night scene mode is selected even after the flashing, the first main capacitor 61 and the second main capacitor 62 are charged and finally fully charged, but the charging voltage V1 of the first main capacitor 61 is charged. Charging is started from a state in which the charging voltage V2 of the second main capacitor 62 is higher than that. When the first main capacitor 61 reaches the specified charging voltage, the light emitting diode 67 is turned on. Of course, the second main capacitor 62 is at or above the specified charging voltage.
[0066]
FIG. 4 shows the relationship between the switches 50, 51, 52, the charging voltages of the main capacitors 61, 62, and the lighting state of the light emitting diode 67. Regardless of whether the strobe switch 50 is on or off, that is, whether or not the charging operation is being performed, when the normal mode is selected and the light amount switch 52 is on, the charging voltages of the first main capacitor 61 and the second main capacitor 62 V1 and V2 are kept the same.
[0067]
For example, as described above, when there is a difference between the charging voltages V1 and V2 of the first main capacitor 61 and the second main capacitor 62 after strobe lighting in the night scene mode, the normal mode is selected and the light amount switch 52 is turned on. Then, a part of the electric charge of the second main capacitor 62 having a high charging voltage moves to the first main capacitor 61 via the light amount switch 52, whereby the charging voltages of the first and second main capacitors 61, 62 are obtained. V1 and V2 are the same.
[0068]
As described above, when the strobe switch 50 is on when the light amount switch 52 is on, the charging voltages V1, V2 of the first and second main capacitors 61, 62 rise while maintaining the same voltage, When each charging voltage V1, V2 reaches the specified charging voltage, the light emitting diode 67 is turned on.
[0069]
When the light amount switch 52 is off, the light amount switch 52 is switched from on to off and the charging voltages V1 and V2 of the first and second main capacitors 61 and 62 are the same, and the strobe light is emitted in the night scene mode. As described later, the charging voltages V1 and V2 of the first and second main capacitors 61 and 62 may be different.
[0070]
In the former case, as in the case where the light amount switch 50 is on, the light emitting diode 67 is activated when the charging voltages V1, V2 of the first and second main capacitors 61, 62, which are the same voltage, are equal to or higher than the specified charging voltage. Light. In the latter case, the charging voltages V1 and V2 rise while the charging voltage V2 of the second main capacitor 62 is higher than the charging voltage V1 of the first main capacitor 61, and the charging voltage V1 reaches the specified charging voltage. When this occurs, the light emitting diode 67 is turned on. Of course, at this time, the charging voltage V2 is higher than the charging voltage V1, and thus is equal to or higher than the specified charging voltage.
[0071]
Therefore, regardless of whether the light quantity switch 52 is on or off, the charging voltage V2 of the second main capacitor 62 is equal to or higher than the charging voltage V1 of the first main capacitor 61, and the charging voltage V1 is equal to or higher than the specified charging voltage. If 67 is lit, the second main capacitor 62 is also charged to a specified charge voltage or higher.
[0072]
Then, even after the light emitting diode 67 is turned on and strobe light emission is possible, the light amount switch 52 is switched from on to off and from off to on, that is, the normal mode and the night scene mode are switched. However, the charging voltages V1 and V2 of the first and second main capacitors 61 and 62 are maintained at a specified voltage or higher, and a state where strobe light emission is possible is maintained. Of course, the light emitting diode 67 is also kept on.
[0073]
Thus, even if the photographer confirms the lighting of the light-emitting diode 67 and then performs photographing by switching the photographing mode with the mode operation member 8, if the strobe operation member 9 is set to the on position, Shooting does not fail because the flash is always emitted.
[0074]
FIG. 5 shows an example in which three main capacitors are provided. Light amount switches 74 to 76 are connected to one ends of the first to third main capacitors 71 to 73, respectively. In addition, diodes 77 to 79 are connected in parallel to the light quantity switches 74 to 76, respectively. The main capacitors 71 to 73 are operated when the booster circuit 56 is operated regardless of whether the light quantity switches 74 to 76 are turned on or off. Charging is possible with a current flowing through one of the corresponding diodes 77-79. .
[0075]
For example, the lens-equipped film unit is configured so that the diaphragm can be switched in three stages. When a small diaphragm having the smallest diaphragm aperture diameter is selected, all the light quantity switches 74 to 76 are turned on to open the diaphragm. Only the light quantity switch 74 is turned on when the large aperture having the largest aperture is selected, and the light quantity switch 74 and the light quantity switch 75 are turned on when the middle diaphragm between the small diaphragm and the large diaphragm is selected. Is done. As a result, the flash emission amount is changed in three steps according to the aperture. In this case, since the light quantity switch 74 is always on, the light quantity switch 74 may not be provided.
[0076]
In the above example, the strobe light emission amount is changed in three steps. However, the strobe light emission amount can be changed in three steps or more by changing the combination of the main capacitors used during the strobe light emission. For example, assuming that the capacitances of the first to third main capacitors 71 to 73 are different from each other, the amount of strobe light emission can be changed in seven steps by the combination of turning on and off the light amount switches 74 to 76.
[0077]
In each of the above embodiments, the lens-fitted film unit that manually switches the aperture has been described as an example. However, the present invention can also be used when the subject brightness is measured by a sensor and the aperture is switched based on the measurement result.
[0078]
【The invention's effect】
As described above, according to the lens-fitted photo film unit of the present invention, one or more main capacitors out of a plurality of main capacitors connected in parallel to each other are turned on / off in conjunction with aperture switching. In addition, each main capacitor is charged at the same time, regardless of whether the light switch is on or off. Even when the switch is switched from off to on, the flash can always be emitted normally.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the appearance of a lens-fitted photo film unit embodying the present invention.
FIG. 2 is a block diagram illustrating a mechanism for switching between an aperture and a shutter speed.
FIG. 3 is a circuit diagram showing a circuit configuration of a strobe device.
FIG. 4 is an explanatory diagram showing a relationship between a charging voltage of a switch and a main capacitor and a lighting state of a light emitting diode.
FIG. 5 is a circuit diagram showing an example in which three main capacitors are provided.
[Explanation of symbols]
4 Shooting lens
8 Mode selection member
9 Strobe operation member
10 Strobe flash unit
52,74-76 Light switch
56 Charging circuit
61, 62, 71-73 Main capacitor
63, 77-79 Diode

Claims (2)

In a lens-equipped film unit having an aperture switching mechanism for switching the aperture of a taking lens and a strobe device that adjusts the amount of flash emission according to the aperture,
The strobe device includes a plurality of main capacitors connected in parallel so as to be charged by a charging circuit and discharged by a strobe discharge tube, and at least one of the plurality of main capacitors. A light amount switch connected to each end and turned on / off in conjunction with aperture switching, and a diode connected in parallel to each light amount switch to allow charging of the main capacitor when the light amount switch is turned off This is a film unit with a lens. 2. The lens-fitted photo film unit according to claim 1, wherein the film sensitivity of the pre-loaded photographic film is ISO 1600 or more.

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