JPS631568B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flash camera device that is a combination of a photographic camera and a strobe device, and in particular, to a flash camera device that is a combination of a photographic camera and a strobe device. , when the brightness is appropriate or when the main discharge capacitor of the strobe device is fully charged, the second display device is operated, and when the power supply capacity drops to a predetermined level, the above-mentioned first display device is operated.
and a display device in which the second display device is inoperable.

Japanese Unexamined Patent Publication No. 53-83736 discloses a system in which the charging voltage of the main discharge capacitor of a strobe device and the brightness of the subject can be displayed using a single display element by switching the power switch. Japanese Utility Model Application Publication No. 15237/1987 is a method for displaying the brightness of the subject and the brightness of the subject, and by combining the two, it is proposed that a considerably wide display can be obtained.

Among these displays, the power supply voltage confirmation display is the most important because without the power supply voltage, the brightness cannot be checked and the strobe device cannot be operated.

However, even if the two are combined, although it is possible to display the power supply voltage when checking the subject brightness, it is not possible to display the power supply voltage when the strobe device is operating.

Therefore, in this case, it is necessary to return to the brightness checking operation and check the power supply voltage, or to install a changeover switch to check the power supply voltage and check the switching power supply, which results in a lack of operability. become.

Furthermore, since the charging display of the main discharge capacitor is displayed only when the charging process is complete, the charging process is completely unknown, and the user cannot be sure whether the device is operating normally or not, which can cause a sense of anxiety to the user. Become.

Therefore, the present invention has been made to solve these problems, and will be described below with reference to the drawings.

FIG. 1 is a block diagram of an electrical circuit portion of a flash camera device including a display device A according to the present invention.

In the figure, 1 is a strobe device including a main discharge capacitor, a flash discharge tube, etc., 2 is a power source, and 3 is a supply of the power source 2 to the strobe device, and a display device A according to the present invention.
4 is a voltage detection circuit that detects the power supply voltage; 5 is a normally open switch that is closed by pressing the shutter release button (not shown) halfway; 6 is a switch that detects light from the subject. 7 is a charging voltage detection circuit for detecting the charging voltage of the main discharge capacitor of the strobe device 1; 8 is operated by signals from the light receiving circuit 6 and the charging voltage detection circuit 7; a first display circuit 9; This is a control circuit that controls the operation of the second display circuit 10 which has a notification mode different from the notification mode of the first display circuit 9.

The operation will be described below.

First, in the case of natural light photography, the power switch 3 is in the state shown in the figure, that is, the power supply 2 is in the strobe device 1
Since the display device A according to the invention is located in a position where no power is supplied to the display device A, the power supply 2 is not supplied to the display device A according to the invention unless the switch S is closed. Close 5.

When the normally open switch 5 is closed, the power supply 2 is supplied to the voltage detection circuit 4, its voltage value is detected, and if the voltage value is higher than a predetermined level, the voltage value is sent to the control circuit 8 and the power switch. 3 to the light receiving circuit 6.

When the power supply 2 is supplied, the light receiving circuit 6 detects the brightness of the subject, outputs an output signal corresponding to the detected brightness of the subject, and supplies the output signal to the control circuit 8 .

The control circuit 8 starts operating in response to an output signal from the light receiving circuit 6, and controls the operations of the first display circuit 9 and the second display circuit 10.

That is, if the subject brightness detected by the light receiving circuit 6 is, for example, a proper brightness, the control circuit 8 controls the light receiving circuit 6.
The operation is controlled by an output signal corresponding to the appropriate brightness from the display circuit 10, and is operated to operate, for example, the second display circuit 10. Of course, the first
It goes without saying that the operation of the display circuit 9 is controlled by the control circuit 8 so that it operates when the light receiving circuit 6 detects low brightness.

Next, the case where the power switch 3 is switched from the state shown in the figure to the state shown by the broken line, that is, the case where the power supply 2 is supplied to the strobe device 1 will be described.

In this case, the strobe device 1 starts operating because the power supply 2 is supplied, that is, charging of the main discharge capacitor starts, and at the same time, the charging voltage detection circuit 7 that detects the charging voltage also starts operating.

The charging voltage detection circuit 7 starts controlling the control circuit 8 at the same time that power is supplied to the strobe device 1, that is, at the same time as charging of the main discharge capacitor starts, and this control state is set to the charging voltage of the main discharge capacitor. It is designed so that it changes when it is completed.

That is, when the power switch 3 is switched as shown by the broken line, the control circuit 8 is supplied with the power 2 only through the voltage detection circuit 4 without going through the normally open switch 5, and the charging voltage as described above is applied to the control circuit 8. The operation of the first display circuit 9 and the second display circuit 10 is controlled by the operation of the detection circuit 7.

Therefore, when charging of the main discharge capacitor is not completed, for example, the first display circuit 9 is operated, and when charging is completed, for example, the second display circuit 10 is operated, and the state of charge of the main discharge capacitor is displayed. is also displayed for two states.

Note that a first display circuit 9 and a second display circuit 10 are used to check the brightness during natural light photography and to display the charging voltage of the main discharge capacitor when using a strobe device.
As mentioned above, the power supply 2 is supplied to the control circuit 8 that controls the operation of the power supply 2 through the voltage detection circuit 4 in both cases. This voltage detection circuit 4
stops the supply of power 2 to the control circuit 8. Therefore, neither the first display circuit 9 nor the second display circuit 10 operates, that is, when the normally open switch 5 is closed or the power switch 3 is switched, neither display circuit is activated. If it doesn't work,
This will notify that the capacity of the power source 2 has decreased.

FIG. 2 is an electric circuit diagram showing a specific example of a flash camera device having a display device A according to the present invention, and parts having the same numbers as those in FIG. 1 have the same functions.

First, let us consider the case of natural light photography in the circuit configuration as shown.

In the illustrated circuit configuration, when the normally open switch 5 is closed, for example, by pressing the shutter button (not shown), the power supply 2 is supplied to the resistor 1 of the voltage detection circuit 4 via the normally open switch 5.
1 and 12.

At this time, the voltage of the power supply 2 is divided by the resistors 11 and 12, and if the voltage value obtained across the resistor 12 is equal to or higher than a predetermined level, the transistor 13 becomes conductive, and the transistor 14 becomes conductive. ,
Power supply 2 is supplied to control circuit 8, first display circuit 9, and second display circuit 10.

That is, this voltage detection circuit 4 determines the capability of the power supply 2 by dividing the voltage of the power supply 2 by the resistors 11 and 12, and depending on whether or not this divided voltage can make the transistor 13 conductive. Of course, if the transistor 13 does not become conductive, the transistor 14 also remains non-conductive, and the power supply 2 is not supplied to each circuit as described above, and the first display circuit 9 and the second display circuit 1
0 does not operate, and it is possible to notify that the capacity of the power source 2 has decreased.

Further, when the normally open switch 5 is closed as described above, the light receiving circuit 6 is supplied with the power 2 via the power switch 3, so the light receiving element 15 begins to detect the brightness of the subject.

At this time, if the subject brightness is above a predetermined level, that is, if the brightness is appropriate, a photocurrent flows through the light receiving element 15, which is a phototransistor, for example, and this photocurrent is supplied as the base current of the transistor 16, so that the transistor 16 is in a conductive state. becomes. When the transistor 16 becomes conductive, the voltage detection circuit 4
Due to this operation, the base and emitter of the transistor 18 of the control circuit 8 to which the base current was to be supplied from the power supply 2 through the resistor 17 are short-circuited, so the transistor 18 does not become conductive, and the first display The lamp 19, which is the circuit 9, is never lit. That is, in this case, the base current of the transistor 21 of the control circuit 8 is supplied from the power supply 2 via the normally open switch 5, the voltage detection circuit 4, and the resistor 20, and the lamp, which is the second display circuit 10, is supplied with the base current of the transistor 21 of the control circuit 8. 22 will be lit.

Conversely, if the brightness of the subject is below a predetermined level, that is, if the brightness is low, the base resistor 23 is set so that the transistor 16 will not become conductive due to the photocurrent flowing through the light receiving element 15, so that the transistor 18 will not become conductive. A base current is supplied from the power supply 2 via the normally open switch 5, the voltage detection circuit 4, and the resistor 17, and the transistor 18 becomes conductive.

Therefore, the lamp 19, which is the first display circuit 9, lights up, and when the brightness is appropriate as described above, the transistor 21, which was in a conductive state, becomes non-conductive, so that the lamp 22, which is the second display circuit 10, turns on. never lights up.

In the case of natural light photography, the display device A according to the present invention performs the above-mentioned operation by closing the normally open switch 5, and therefore the lamp 19
For example, if a lamp that lights up in red and a lamp that lights up in green are used as the lamp 22, low brightness can be reported when the red light is on, and appropriate brightness can be reported when the green light is on.

Next, a case will be described in which the power switch 3 is switched from the state shown in the figure to the position shown by the broken line and the power supply 2 is supplied to the strobe device 1.

In this case, a DC-DC converter circuit 2 that includes an oscillation transistor and an oscillation transformer and converts the power supply 2 into boosted direct current when the power supply 2 is supplied.
4 starts operating, and the main discharge capacitor 26 is charged.

At this time, the charging voltage detection circuit 7 described above divides the voltage across the base capacitor 25, where a voltage proportional to the charging voltage value of the main discharge capacitor 26 appears, by the resistors 27 and 28 and detects it by the transistor 29. The transistor 29 maintains a non-conducting state until the charging voltage value of the main discharge capacitor 26 reaches a voltage value that allows the flash discharge tube 30 to emit light, that is, when it is not charged. That is, it is provided so as to maintain a conductive state when charging is completed.

Therefore, when the transistor 29 maintains a non-conducting state, the light receiving circuit 6 is disconnected from the power source 2 by switching the power switch 3, and the transistor 1 is disconnected from the power source 2.
Since the base current of 6 is not supplied and the transistor 16 is also maintained in a non-conducting state, the transistor 18 is made into a conducting state and the transistor 21 is made into a non-conducting state as in the case described above, and the first display circuit 9 The lamp 19 will be lit.

Furthermore, when the charging of the main discharge capacitor 26 is completed and the transistor 29 maintains the conductive state, the base current is supplied to the transistor 16 via the transistor 29 and the base resistor 23, so the transistor 16 becomes conductive. , as described above, the transistor 18 is made non-conductive and the transistor 21 is made conductive, so that the second display circuit 1
0 lamp 22 lights up.

Therefore, as in the case described above, by using the lamp 19 that lights up in red and the lamp 22 that lights up in green, it is possible to notify the charging state of the main discharge capacitor 26 in two states. The element is the same as the notification element at the time of brightness check.

Note that even when notifying the charging state of the main discharge capacitor 26, the power supply 2 is supplied to the control circuit 8, the first display circuit 9, and the second display circuit 10 as follows.
It is passed through a power switch 3 and a voltage detection circuit 4,
If the power supply capacity decreases, the first display circuit 9 and the second display circuit 10 will not operate together, as in the case of the brightness check described above.

3A and 3B show other embodiments of a part of the control circuit 8 of the display device A according to the present invention, the first display circuit 9, and the second display circuit 10, which are used as notification elements. , Figure A shows two lights emitting light of different colors.
An embodiment in which LEDs 31 and 32 are used and a two-color LED 33 with a common cathode is used is shown in FIG.

As shown, in both A and B of FIG. 3, due to the operation of the transistor 18 which has different operating states at low brightness and proper brightness, and when uncharged and when charging is completed,
Controls the operation of transistors 34 and 35, and
Two types of light emitters 33: 31, 32 and LED 33
It controls the current supply to a and 33b, that is, the light emission operation.

As is well known, LEDs are smaller than ordinary lamps and are effective as notification elements for flash camera devices. In particular, three-terminal LEDs with a common cathode, as shown in Figure 3 (b), emit light with different colors. The two bodies are compactly installed in one mold, making it a very effective notification element.

In addition, the resistor 37 in FIG.
When the LED 33a is lit, the transistor 35 is reverse biased to maintain a non-conducting state,
This is a resistor that prevents LED 32 or LED 33b from lighting up, and is a resistor that prevents LED 32 or LED 33b from lighting up.
It goes without saying that 8 is designed to prevent the current flowing through the resistor 37 when the transistor 35 is turned on from being supplied to the LED 33a.

Furthermore, although the charging voltage detection circuit 7 of the main discharge capacitor 26 in the above-described embodiment detects the voltage across the base capacitor 25, the voltage value of the main discharge capacitor 26 may be directly or proportionally expressed. Of course, it is possible to detect voltage, and furthermore, although transistors are used as switching elements in all cases, it is of course possible to use SCRs in places where they can be replaced with SCRs.

As explained above, the present invention operates the first display circuit when the brightness is low or when the main discharge capacitor is not charged, and operates the second display circuit when the brightness is appropriate or when the main discharge capacitor is fully charged. If the capacity of the power supply decreases, neither of the first and second display circuits described above will operate, indicating that the power supply is exhausted. Therefore, when checking either the brightness or the charging voltage of the main discharge capacitor, This is an excellent display device for the flash camera device, which does not require any operation to check the power supply voltage, and can also display the charging process of the main discharge capacitor, so it does not make the user feel anxious. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an electric circuit of a display device of a flash camera device according to an embodiment of the present invention, and FIG. 2 is a block diagram of a flash camera device equipped with a specific embodiment of a display device according to the present invention. The electrical circuit diagrams in FIGS. 3A and 3B are diagrams of other embodiments of the circuits indicated by numbers 8, 9, and 10 in FIG. DESCRIPTION OF SYMBOLS 1... Strobe device, 2... Power supply, 3... Power switch, 4... Voltage detection circuit, 5... Switch, 6... Light receiving circuit, 7... Charging voltage detection circuit,
8...control circuit, 9, 10...display circuit.

Claims (1)

[Claims] 1. It has a DC-DC converter circuit that includes an oscillation transistor, an oscillation transformer, etc. and converts the power supply voltage into boosted direct current to charge a main discharge capacitor, and a flash discharge tube that emits light using the charging energy of the main discharge capacitor. A display device for a flash camera device that combines a strobe device and a photographic camera, the display device comprising a power supply voltage detection circuit having a first switch element that turns on when the power supply voltage is equal to or higher than a predetermined level, and detecting subject brightness. a first light-receiving circuit having a first light-emitting element; a display circuit;
a second display circuit having a second light emitting element; and the output signal when the charging voltage of the main discharge capacitor reaches or exceeds the predetermined level or the light receiving circuit when the subject brightness is at or above the predetermined level. A second switch element is connected to the first display circuit and is turned on when an output is applied thereto, and is turned on when the power supply voltage is applied through the first switch element, causing the first light emitting element to emit light. , a third switch element that is turned off by the second switch element that is turned on and turns off the first light emitting element; and a third switch element that is connected to the second display circuit and is in the on state. a control circuit having a fourth switch element that is turned off by the switch element and turns on when the third switch element turns off to control the light emitting operation of the second light emitting element; the power source and the power source voltage; a normally open switch provided between the power supply and the strobe device, the light receiving circuit, and the power supply voltage detection circuit; the normally open switch provided between the power supply and the strobe device; By closing the switch, the power source is connected to the light receiving circuit and the power supply voltage detection circuit, and when the power source is connected to the strobe device, the connection between the power source and the light receiving circuit is disconnected and the normally open switch is closed. and a power switch that connects the power supply to the power supply voltage detection circuit without going through the normally open switch, and connects the control circuit and the first and second display circuits through the first switch element. A display device for a flash camera device that supplies the power to the flash camera device.