JPS62297831A - Power supply device for camera - Google Patents

Abstract

PURPOSE:To stably operate respective circuit parts by providing a camera body with a power supply output means for supplying electric power to a circuit including a data inprinting light source and a power supply output means for supplying DC power controlled with a constant voltage. CONSTITUTION:Direct current power not controlled with a constant voltage is supplied from a battery 3 having comparatively large current capacity and arranged on the camera body 1 side to a data inprinting LED 7 fitted to a back cover 2 and consuming a comparatively small current. On the other hand, the DC power obtained by controlling the DC power of the battery 3 with the constant voltage by a DC/DC converter 5 is supplied to an interval control circuit 9 and a calendar circuit 10 fitted to the back cover 2 and consuming a comparatively small current. In addition, a data are power supplying part 23 consisting of plural conductive pins is formed on the back cover 2. A connection part 25 for transmitting signals, inprinting photographing data and DC power from the body 1 side to the back cover 2 side is arranged on a position opposed to a connection part 23 in the body 1. The connection part 25 is electrically connected with the connection part 23 when the back cover 2 is closed to the body 1 side.

Description

[Detailed description of the invention] 3. Detailed description of the invention [Industrial application field] The present invention relates to a power supply device for a camera.

[Prior Art] Fig. 3 is a circuit diagram of a power supply circuit of a camera showing a first conventional example. A camera back cover 2 is attached which includes a light emitting diode for calculation (hereinafter referred to as an LED for photography) 7 and a data photography control circuit 31 for controlling it.

The camera body i is equipped with a battery 3 for supplying power to each circuit within the camera body l, and drives a motor for winding the film and charging the shutter, as well as a magnet provided in the shutter and release device. DC power is directly supplied from the battery 3 to the camera drive circuit 4 for photometry, shutter, etc.
The signal is supplied to a camera control circuit 6 for controlling camera operations such as speed.

On the other hand, in the camera back cover 2, DC power is supplied from a battery 32 having a smaller current capacity than the battery 3 to the calculation LED 7 and the data imprint control circuit 31. A data bus B is connected between the data pack control circuit 31 and the data pack control circuit 31.

Data is exchanged via the . In addition, LE for arithmetic
The display of D7 is controlled by the data imprint control circuit 31.

FIG. 4 is a circuit diagram of a camera power supply circuit showing a second conventional example, and compared to the first conventional example shown in FIG. 3, it requires a larger current capacity than the data imprint control circuit 31. The DC power supply to the calculation LED 7 is provided by the battery 3 on the back of the camera M2.
DC power is not supplied from the battery 3 of the camera body l, but is supplied from the battery 3 of the camera body l, which has a larger current capacity than the battery 33.

[Problems to be Solved by the Invention] In the first conventional example described above, it is necessary to provide batteries 3 and 32 with relatively large current capacities on both the camera body l side and the camera back cover 2 side. Due to its shape, the rear M2 side of the camera cannot accommodate a battery with a large current capacity, and cannot be equipped with a DC-DC converter, so the data imprint control circuit 31 requires a small DC power supply that is not controlled at a constant voltage. There was a problem in that the current was supplied from the battery 32 with a large current capacity and there was a risk of malfunction.

Furthermore, in the second conventional example described above, the calculation LED 7
DC power is supplied from the battery 3 with a relatively large current capacity on the camera body L side, but the data imprint control circuit 31 is supplied with DC power that is not controlled at a constant voltage as in the first conventional example described above. There was a problem that there was a risk of malfunction.

[Object of the Invention] The object of the present invention is to solve the above-mentioned problems, and to provide a constant voltage control system for accessory devices such as the data imprint control circuit 31 provided in areas such as the camera back cover 2 where a large storage space cannot be secured. It is an object of the present invention to provide a power supply device for a camera that can supply a DC power source to other accessory devices such as a calculation LED 7 and other DC power sources from the camera body side.

[Structure of the Invention] The present invention provides a first power supply output means for supplying a first DC power supply to a first circuit including a data imprinting light source of a camera accessory device, and a second power supply output means that is controlled at a constant voltage. The present invention is characterized in that the camera body is also provided with a second power output means for supplying DC power to a second circuit including a control means of the camera accessory device.

[Example 1] Fig. 1 is a circuit diagram of a power supply circuit of a camera incorporating a data imprinting and display device showing one embodiment of the present invention.
The figure is an external view showing a state where the back M2 of the camera equipped with the power supply circuit of FIG. 1 is opened.

In FIGS. 1 and 2, the same parts as in FIGS. 3 and 4 are designated by the same reference numerals.

In this embodiment, DC power that is not subjected to constant voltage control is supplied from a battery 3 with a relatively large current capacity provided on the side of the camera body l to the LED 7 for calculation which consumes a relatively large current, and the battery 3 mentioned above A DC power source obtained by controlling a constant voltage by a DC-DC converter 5 is supplied to an interval control circuit 9 and a calendar circuit 10, which consume relatively small currents, and which correspond to the data imprint control circuit 31 of the conventional example.

As shown in FIG. 2, on the back side of the camera M2, behind the film pressure bonding plate 21, date data, shooting data, etc. are captured from the back side of the film in conjunction with the exposure of the film, and are displayed on the outside of the back side M2. A data imprint and display device 22 is provided below the film pressure bonding plate 21, and data and power supply connection portions 23 each consisting of a large number of conductive pins are provided. In the camera body I, signals for controlling data imprinting and the operation of the display device 22 and photographing data for imprinting are placed below the exposure opening 24 and at a position facing the connection part 23 on the back M2. A connecting portion 25 is provided for transmitting DC power from the camera body 1 side to the device 22 on the back M2 side.

This connecting portion 25 is provided so as to be electrically connected to the connecting portion 23 when the back M2 is closed to the camera body 1 side.

In Fig. 1, an electric current having a relatively large current capacity? T! !
The positive electrode of No. 3 is connected to a power input terminal 4a of a camera drive circuit 4 for driving a motor for winding the film and charging the shutter, and a magnet provided in the shutter and release device, and also for stabilizing the DC voltage. The input terminal 5a of the DC-DC converter 5 is connected to the input terminal 5a of the DC-DC converter 5. Further, the positive electrode of the battery 3 is connected to the anode of the diode D1, and is also connected to the anode of the calculation LED 7 via the connection terminal 25a of the connection part 25 and the connection terminal 23a of the connection part 23 of the back M2. Further, the negative electrode of the battery 3 is connected to the power input terminal 4b of the camera drive circuit 4 and the DC
- It is connected to the ground together with the ground terminal 5C of the DC converter 5, and the ground on the camera body 1 side is the connection terminal 25f of the connection part 25 and the connection terminal 23f of the connection part 23 on the back M2.
is connected to the ground of the data calculation and display device 22 on the back side of the camera M2.

Hereinafter, the voltage of the positive electrode of the battery 3 with respect to the ground will be referred to as Vcc. This voltage Vcc is obtained directly from the battery 3, so the current capacity is relatively large, but since it is not constant voltage controlled, the output voltage Vcc may fluctuate. The signal is supplied to the camera drive circuit 4 and the calculation LED 7 on the camera back cover 2 side.

The output terminal 5b of the DC-DC converter 5 is a diode D.
! The cathode of the diode D is connected to the cathode of the diode D and the power input terminal 6a of the camera control circuit 6, as well as the connection terminal 25b of the connection part 25 and the connection part 23 of the back cover 2. Connection terminal 23
power input terminal 9 of the interval control circuit 9 via b.
a and the anode of diode D. below,
The voltage on the cathode side of the diode D1 is called VDD.

Since this voltage VDD is obtained via the DC-DC converter 5, its current capacity is smaller than that of the voltage Vcc, but it is controlled at a constant voltage to stabilize the voltage, and the camera control circuit 6 and the interval control circuit 9 It is also used as a power supply for control circuits such as a calendar circuit IO.

11 is a main switch for starting the camera control circuit 6; one end of the main switch 11 is connected to the camera control circuit 6, and the other end of the main switch 11 is connected to ground. 12 is a release switch, and one end of the release switch 12 is connected to the camera control circuit 6, and a connection terminal 25d of the connection part 25 and a connection terminal 23d of the connection part 23 of the back M2.
It is connected to the interval control circuit 9 via.

13 is a photometry switch, one end of which is connected to the camera control circuit 6, and the connection part 2.
It is connected to the interval control circuit 9 via the connection terminal 25e of the connection part 23 of the back M2.

Note that the other ends of the release switch 12 and the photometry switch 13 are each connected to ground. Note that the photometry switch 13 is turned on when the release button is pressed down to the first step, and the photometry switch 13 and the release switch 12 are turned on when the release button is pressed down to the second step.

The camera control circuit 6 has a main switch 11. Release/
When the switch 12 and the photometry switch 13 are turned on, operation control data is output to the camera drive circuit 4 via the data bus B in response to the information of those switches, and the control signal is output via the control signal output terminal 6b. An operation control signal is output to the control signal input terminal C8 of the DC-DC converter 5, the DC-DC converter 5 is activated, and a predetermined constant voltage controlled DC voltage is output from the power output terminal 5b of the DC-DC converter 5. Ru. Further, the connection terminal 2 of the connection section 25 is connected between the camera control circuit 6 and the interval control circuit 9.
5c and a data bus B connected to the connection terminal 23c of the connection unit 23, and data on the number of shots and film sensitivity and calculation signals are transmitted from the camera control circuit 6 to the interval control circuit via the data bus B. 9.

In the data calculation and display device 22 on the back side of the camera M2, reference numeral 15 is a backup battery for the calendar circuit 10 that includes a built-in RAM and a clock circuit, and the positive electrode of the battery 15 is connected to the anode of the diode D4. The cathode of the diode D4 is connected to the cathode of the diode D3 and the power input terminal tea of the calendar circuit 10. On the other hand, the negative electrode of the battery 15 is connected to the ground as well as the ground terminal 9b of the interval control circuit 9 and the ground terminal 10b of the calendar circuit IO. Further, the cathodes of seven LEDs for calculation are connected to the calendar circuit 10.

Reference numeral 14 denotes a plurality of setting switches for setting interval shooting conditions such as interval time, number of shooting frames, and start time. One end of each setting switch 14 is connected to the interval control circuit 9, and the other end is connected to ground.

The interval control circuit 9 outputs a predetermined signal to the camera control circuit 6 via the data bus B according to the interval time and number of frames set by the setting switch 14 to control interval shooting of the camera. At the same time, data such as the number of shots and film sensitivity inputted from the camera control circuit 6 via the data bus B are outputted to the calendar circuit IO via the data bus B3.

Further, between the interval control circuit 9 and the calendar circuit 10, data such as interval time, set number of frames, number of shots, film sensitivity, etc. are transmitted from the interval control circuit 9 to the calendar circuit 10 via a data bus B3.

This calendar circuit 1O includes a clock circuit for imprinting the date and time, and a RAM in which the above-mentioned data transmitted from the interval control circuit 9 is stored.

The calendar circuit 10 and the display/imprint LCD 8 are connected via a data bus B4, and from the calendar circuit 10 to the display LCD 8 via the data bus B4,
Display data for D8 is provided. This display and photo LCD 8 is an external display L on the back of the camera back cover 2.
It is equipped with a CD and an LCD for imprinting data on the film by illumination of the above-mentioned imprinting LED 7.

In addition, when the back cover 2 is closed, the LC for display and photography
D is in an on state, and on the other hand, when the back cover 2 is opened, it is in an off state.

The operation of the power supply circuit of this embodiment configured as described above will be described below.

First, when the back cover 2 of the camera is opened as shown in FIG. Voltage V to circuit 9 and calendar circuit IO
The supply of DD has been cut off. When the back cover 2 is open, there is no need to supply DC power to the ED 7 and the interval control circuit 9, while the calendar circuit 1O, which requires constant power, is supplied with DC power from the backup battery 15. Power is supplied.

Next, when the back cover 2 of the camera is closed on the camera body l, the connection terminals of the connection part 23 and the connection part 25 are connected, voltage Vcc is applied from the battery 3 to the photography LED 7, and the DC - The output voltage VDD of the DC converter 5 is applied to the interval control circuit 9 and the calendar circuit [0] on the back cover 2 side of the camera. In addition, the camera control circuit 6 and the interval control circuit 9 are connected to the data bus Bl Lurie's switch 1.
2 and the line S of the photometric switch 13.

First, the main switch 11 is turned on, and when the photometry switch 13 is turned on by pressing the first step of the release button, the camera control circuit 6 is activated and the control signal output terminal 6b is turned on.
An operation control signal is sent to the DC-DC converter 5 via the DC-DC converter 5, and the DC-DC converter 5 is activated in response to the operation control signal.
A constant voltage controlled DC voltage VDD is supplied from the output terminal 5b to the camera control circuit 6 via the diode D2, further to the interval circuit 9 via the connection terminals 25b and 23b, and to the calendar circuit IO via the diode D3. . Note that if the main switch 11 is off, even if the photometry switch 13 is on, the camera control circuit 6
does not start, therefore, the DC-DC converter 5 does not start and voltage VDD is not output.

When the main switch 2 and the metering switch 13 are turned on and metering starts, the camera control circuit 6 sends data such as film sensitivity and number of shots to the camera back cover 2 via the data bus B. It is transmitted to the interval control circuit 9 of. Furthermore, when the second stage of the release button is pressed and the release switch 12 is turned on, the camera starts releasing the film and the film is exposed. At this time, the camera control circuit 6 An imprint signal is output to the interval control circuit 9.

In response to this, the interval control circuit 9 outputs data such as the film sensitivity information, the capture signal, and the number of shots inputted from the camera control circuit 6 to the calendar circuit 10 via the data bus B3.

At the timing of this imprint signal, the calendar circuit 10 turns on the calculation LED 7 for a time corresponding to the film sensitivity information, thereby imprinting the data displayed on the calculation LCD onto the film.

'That is, the light emitted from the photo LED 7 passes through the window 21a formed in the pressure bonding plate 21 and exposes the film.

Note that data such as the number of shots is stored in R in the calendar circuit IO.
Stored in AM.

Furthermore, in the case of interval shooting, the interval control circuit 9 controls the line S of the release switch 12 and the line S of the photometry switch 13 according to the shooting conditions set by the setting switch 14, such as the interval time, the number of shooting frames, and the start time. to the camera control circuit 6 via line S,
After the line S of the photometry switch 13 is grounded, the line S2 of the release switch 12 is grounded to output the control signal, and in response, the camera control circuit 6 controls the camera operation in the same manner as described above.

Note that the interval control circuit 9 consumes almost no DC power except during data communication with the camera control circuit 6 and during interval photography, and the current consumption of the calendar circuit 10 is extremely small, for example, 3 μ8 degrees.

Roughly speaking, when the back cover 2 is closed, the battery 3
The output voltage Vcc is applied to the camera control circuit 6, the interval control circuit 9 and the calendar circuit lO via the diode D1.
is output to . Therefore, since DC power is supplied to the device 22 on the back cover 2 side from the battery 3 of the camera body 1, the battery 15 on the back cover 2 side can be used for a longer period of time compared to the conventional example. At the same time, the current capacity of the battery 15 on the back M2 side can be reduced to reduce the size.

As explained above, DC power that is not constant voltage controlled is supplied from the battery 3 with a relatively large current capacity provided on the camera body l side to the LED 7 for calculation which consumes a relatively large amount of soil, and the above-mentioned electric power m3 A DC power supply with constant voltage control of the battery voltage is supplied to the interval control circuit 9 and calendar circuit 10 corresponding to the data imprint control circuit 31 of the conventional example, so that the DC power supply has characteristics corresponding to the respective circuit operations. This has the advantage that each circuit operates stably and malfunctions are reduced. Furthermore, since the current consumption of the interval control circuit 9 and calendar circuit 10 on the camera back cover 2 side is extremely small, the DC-DC controller 5 will not be overloaded.

[Effects of the Invention] As detailed above, according to the present invention, the first DC power source can be supplied from the camera body side to the first circuit including the data imprinting light source of the camera accessory device. Since the second DC power supply controlled at a constant voltage can be supplied from the camera body side to the second circuit including the control means of the camera accessory device, the accessory device can control the operation of each circuit section. This has the advantage that it is possible to supply a DC power supply with suitable characteristics, and that each circuit section operates stably and malfunctions are reduced.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of a power supply circuit of a camera with a built-in data imprinting and display device, which is an embodiment of the present invention; Fig. 2 is an external view of the camera shown in Fig. 1 with the back cover opened; FIG. 3 is a circuit diagram of a power supply circuit of a camera according to the first conventional example, and FIG. 1 is a circuit diagram of a power supply circuit of a camera according to a second conventional example. l...Camera body, 2...Camera back cover, 3...Battery, 4...Camera drive circuit, 5...DC-DC converter, 6...Camera control circuit, 7...Calculation Description LED. 8... LCD for display and calculation, 9... Interval control circuit, lO... Calendar circuit, 11... Main switch, 12... Release switch, l3... Photometering switch, 14...・Setting switch. Patent applicant Minolta Camera Co., Ltd. Agent
Person Patent attorney Aoyama Ao and two others Figure 3

Claims (1)

[Claims] (1) A first power supply output means for supplying a first DC power supply to a first circuit including a data imprinting light source of a camera accessory device; and a second DC power supply controlled at a constant voltage for supplying a second DC power supply to the camera accessory device. a second circuit supplying a second circuit comprising control means of the device;
A power supply device for a camera, characterized in that the camera body is equipped with a power output means.