JPS6195425A - Memory backup device - Google Patents

Abstract

PURPOSE:To obtain a stable backup function as compared with the use of a button battery by connecting a charging capacitor and using a long-life solar battery to back up a memory. CONSTITUTION:When a power supply of a camera is applied to a power supply terminal 1a, about 5V voltage is applied to a memory circuit 5 to actuate the circuit 5. At that time, the charging capacitor 9 of large capacity is charged with electric energy. Although about 3V voltage is generated by the solar battery 10 built in a camera body including an electronic view finder at that time, the voltage of the battery 10 is not used because about 5V voltage is applied in the positive direction of a diode 7. When the power supply of the camera is turned off, the capacitor 9 starts to discharge to the circuit 5 and the battery 10 charges the capacitor 9 to supply a backup voltage to the circuit 5 and back up the memory function.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a memory backup device for a video camera.

Conventional configuration and problems thereof A conventional memory backup device for a video camera is shown in FIG. In FIG. 1, 1.2 is a voltage adjustment resistor, 3 is a transistor, 4 is a button battery, 6 is a memory circuit, and 6 is a reverse current discharge transistor. First, the transistor 3 is used for switching, and when the camera power supply (10B) is applied to the power supply terminal 1a, the transistor 3 is turned off and voltage is supplied to the memory circuit 6 from the camera power supply. When the camera power is turned off, the transistor 3 is turned on and voltage is supplied to the memory circuit 5 by the button battery 4. Therefore, the memory circuit 5 continues to function as a memory using the button battery 4 even after the camera power is turned off.

However, since the button battery 4 has a limited lifespan, it has the disadvantage that it needs to be replaced again.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned conventional drawbacks and provides a memory backup device using solar cells with a long life.

Structure of the Invention The present invention includes a charging capacitor that is charged by the camera power supply when the camera power is turned on, and a solar cell built into the camera body that is charged when the camera power is turned off. It is configured to back up the memory function.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In Figure 2, 7 and 8 are diodes for preventing reverse current, and 9 is the memory circuit 5 when the camera power (+B) is off.
This is a charging capacitor that banks up the memory function of , one end of which is connected to the input end of the memory circuit 6, and the other end of which is grounded. Reference numeral 1o denotes a solar cell, which is built into the camera body including the electronic viewfinder, and the voltage of this solar cell 10 is applied to the memory circuit 6 and the charging capacitor 9 via the diode 7.

The operation of this embodiment configured as above will be described below.

First, when camera power is applied to the power terminal 1a, a voltage of about 6 volts is supplied to the memory circuit 6 through the diode 8, and the memory circuit 6 is activated. At this time, the large-capacity charging capacitor 9 is charged and electrical energy is stored. Also, at this time, a voltage of approximately 3 volts is generated by the thick IJM battery 10 built into the camera body including the electronic viewfinder, but a voltage of approximately 6 volts is generated in the positive direction of the diode 7.
The voltage of the solar cell 10 is not used because the voltage of the solar cell 10 is applied.

On the other hand, when the camera power is turned off, the charged charging capacitor 9 starts discharging into the memory circuit 6, and at the same time,
The solar cell 1o charges the charging capacitor 9, supplies backup voltage to the memory circuit 5, and backs up the memory function. As described above, according to this embodiment, the memory function works even after the camera power is turned off.

Effects of the Invention As described above, the present invention is equipped with a charging capacitor and uses a long-life solar cell to perform memory backup, so it is possible to create a memory backup amplifier that is more stable than when conventional button batteries are used. It is something that provides functionality.

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[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventional memory backup device, and FIG. 2 is a circuit diagram of a memory backup device in an embodiment of the present invention. 5...Memory circuit, 9...Charging capacitor, 10...Solar cell. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
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Claims (1)

[Claims] It is equipped with a charging capacitor that is charged by the camera power supply when the camera power is turned on, and when the camera power is turned off, the charged charging capacitor and the solar cell built into the camera body including the electronic viewfinder are used as memory. A memory backup device that backs up functions.