JPH09230418A - Power feeding device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply sufficient power to a photographic lens side while maintaining compatibility with conventional cameras without adding new components, etc., by judging voltages of power supply parts and feeding power from the selected power source part of one side to an actuator, based on the judgement. SOLUTION: In the case of feeding power from a battery 7 to a photographic lens 54, a body CPU 1 starts up a DC-DC converter 4 by controlling CTL terminals performing the starting up and the stopping of the converter 4 and then power is fed into the photographic lens 54 via an electrical contact 11. Next, in the case of feeding power from the battery 15 in a data bag 60 to the photographic lens 54 via a camera body 52, the CPU 1 starts up the DC-DC converter 4 and power is fed to the lens 54 via an electrical contact 14. The changing over of power feeding routes is controlled by the judging of the batteries. Consequently, power can be fed to the actuator from the suitable battery of batteries 7.15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power feeding device for a camera, which feeds power to a control unit, a driving unit and the like of the camera.

[0002]

2. Description of the Related Art FIG. 6 is a block diagram showing an example of a conventional power supply device for a camera. In this camera, a taking lens 102 and a data back 103 are attached to a camera body 101. The camera body 101 and the taking lens 102 are electrically connected by electrical contacts 11, 12, 13, and 14. Further, the camera body 101 and the data bag 103 are electrically connected by the electrical contact 18. The data bag 103 is usually stored in the back cover of the camera or the camera body 101.

Inside the camera body 101, a body CPU 1 for controlling the camera body 101 side, a battery 7 for supplying electric power to the camera, and the like are provided. On the other hand, in the photographing lens 102, the master CPU 2 and the slave CP
U3 and the drive circuit 10 and the like are provided. The master CPU 2 is a control unit that controls the power supply of the taking lens 102 and other main controls. The slave CPU 3 is a control unit that performs predetermined control according to the control of the master CPU 2, and in this example, drives and controls the drive circuit 10. Battery checks (BC) 8 and 9 are provided in the camera body 101 and the taking lens 102, respectively. The battery checks 8 and 9 are circuits for checking the voltage value, and monitor the state of the battery voltage.

FIG. 7 is a flowchart showing an example of power supply control of the power supply device of the camera of FIG. First, when the battery 7 is loaded into the camera body 101 in step A1,
The voltage of the battery 7 is constantly applied to the DC / DC converter 4 in the camera body 101 and the body CPU 1. In next step A2, the battery check 8 determines whether or not the voltage of the battery 7 is higher than the voltage at which the reset is released (whether or not the voltage is an operable voltage). When the voltage is high,
In step A3, the body CPU1 is activated, and the body CPU
1 is always in the operable state. On the other hand, when the voltage is not large, the body CPU 1 is reset in step A4. Then, returning to step A2, the voltage of the battery 7 is checked again.

When the body CPU 1 is activated in step B1, it is determined in the next step B2 whether or not the power source activation switch is turned on. For example, when the power supply start switch of the first stroke of the release button is turned on, it is determined that the power supply start switch is on, the process proceeds to step B3, and the battery value is checked by the battery check 8. This battery value is sent to the body CPU 1. When the battery value is not larger than the predetermined value, the process proceeds to step B14, and the body CPU 1 gives a warning and notifies that the battery should be replaced. When the battery value is larger than the predetermined value, the process proceeds to step B4, the DC / DC converter 4 is activated,
Output a stable voltage. Then, in step B5, the timer count is started.

In the next step B6, the camera body 10
Communication is started between the first side and the taking lens 102 side. The voltage is supplied to the master CPU 2 via the electrical contacts 12 and 14. Then, in the next step B7, the master C
PU2 becomes active and communicates with body CPU1,
A power supply request is issued so that power is supplied from the electric contact 11 via the electric contact 13.

In step B8, the battery value is checked again by the battery check 8. When the battery value is not larger than the predetermined value, the process proceeds to step B14 and the same processing as described above is performed. If the battery value is larger than the predetermined value, the process proceeds to step B9. Step B9
Then, the body CPU 1 receives the power supply request signal, controls the transistor 6 to be in the energized state, and supplies power to the inside of the taking lens 102 via the electrical contact 11. After that, master CP
The U2 monitors the voltage of the electrical contact 11 by the battery check 9, and when it determines that the voltage is equal to or higher than a predetermined value, controls the power supply control 2 signal and activates the DC / DC converter 5.

The stable output voltage of the DC / DC converter 5 is supplied to the slave CPU 3 and the slave CPU 3
Is activated by a power-on reset. Then, when the start signal of the drive circuit 10 is input to the slave CPU 3, the drive circuit 10 that is supplied with power via the electrical contact 11 is drive-controlled. In addition, the data back 103
Is powered by a battery 15, and an electric charge is always stored by a backup capacitor 17. The circuit 16 in the data bag 103 exchanges signals with the camera body 101 by the electrical contact group 18. In FIG. 6,
Only the electrical contacts 18 related to power supply are shown.

By the way, in step B9, the transistor 6
After the power is turned on, it is determined in step B10 whether or not the power start switch is on. If it is on, the process returns to step B5. If not, whether the timer count has passed 8 seconds in the next step B11. It is determined whether or not.
When 8 seconds have not elapsed, the process returns to step B10, and when 8 seconds has elapsed, the process proceeds to step B12. And
The energization of the transistor 6 is stopped, and the next step B13
The DC / DC converter 5 is turned off.

[0010]

However, the above-mentioned conventional power supply device for a camera has the following problems. First,
When the power consumption in the taking lens 102 increases, there is a possibility that sufficient power cannot be supplied from the battery 7 into the taking lens 102. Especially,
A plurality of actuators are provided in the taking lens 102, and when they are simultaneously driven, a large current may instantaneously flow, which may affect the operation of other electric circuits. was there.

Secondly, if the photographic lens 102 which consumes a large amount of power is provided with a battery dedicated to power supply or a dedicated electrical contact for external power supply, compatibility with other photographic lenses is maintained. However, there is a problem that the common parts cannot be used and the cost increases. In addition, there is a problem that the user is confused. Thirdly, the battery 1 of the data back 103
It is conceivable that power is supplied from 5 to the inside of the taking lens 102, but if the power is simply drawn, the SINK current is large, and if the SINK current is for a longer time, the data holding voltage of the data back 103 itself should be secured. There is a problem that it may not be possible.

An object of the present invention is to supply sufficient power to the taking lens side while maintaining compatibility with conventional products without adding new parts.

[0013]

In order to solve the above-mentioned problems, the invention of claim 1 is a power supply device for a camera having a camera body and a photographing lens mounted on the camera body. A main control unit provided in the taking lens for performing main control of the taking lens, an actuator provided in the taking lens for driving an optical system of the taking lens, the taking lens and the camera body. An electric contact portion for electrically connecting the electric power source, a first power source portion provided in the camera body for supplying power to the main control portion via the electric contact portion, and a first power source portion mounted outside the camera body. Second power supply unit, the first power supply unit and the second power supply unit
And a voltage determination unit that determines the output voltage value of the power supply unit of
Either one of the first power supply unit or the second power supply unit selected based on the determination of the voltage determination unit,
Power is supplied to the actuator.

According to a second aspect of the present invention, there is provided a power supply device for a camera having a camera body and a photographing lens mounted on the camera body, the power feeding device being provided in the photographing lens and performing main control of the photographing lens. A main control unit, a sub-control unit that is provided in the photographing lens and controls a predetermined process under the control of the main control unit, and an electrical contact that electrically connects the photographing lens and the camera body. Section, a first power source section provided in the camera body for supplying power to the main control section via the electrical contact section, a second power source section mounted outside the camera body, and the first power source section. A first power source unit or a second power source unit selected based on the determination of the voltage determination unit, the first power source unit and the voltage determination unit determining the output voltage value of the second power source unit. One of Characterized by feeding to the slave controller.

According to a third aspect of the present invention, there is provided a power supply device for a camera having a camera body and a photographing lens mounted on the camera body, the power feeding device being provided in the photographing lens and performing main control of the photographing lens. A main controller, an actuator for driving an optical system of the photographing lens, which is provided in the photographing lens, and provided in the photographing lens,
According to control from the main control unit, a sub-control unit that controls driving of the actuator, an electrical contact unit that electrically connects the photographing lens and the camera body, and an electric contact unit provided in the camera body, A first power supply unit that supplies power to the main control unit via an electrical contact unit, a second power supply unit mounted outside the camera body, and a first power supply unit and a second power supply unit. A voltage determining unit that determines an output voltage value, and one of the first power source unit and the second power source unit selected based on the determination of the voltage determining unit is the actuator and the second power source unit. A feature is that power is supplied to the slave control unit.

According to a fourth aspect of the present invention, in the power feeding device for a camera according to any one of the first to third aspects, an auxiliary device mounted outside the camera body for performing an auxiliary operation at the time of photographing. And the second power supply unit is provided in the auxiliary device and supplies power to the auxiliary device. The invention of claim 5 is the invention of claims 1 to 4
In the power supply device for a camera described in any one of 1, the one of the first power supply unit and the second power supply unit having a higher power supply capacity supplies power to the power supply target.

According to a sixth aspect of the present invention, there is provided a power supply device for a camera having a camera body and a photographing lens, the main control section performing main control of the photographing lens, and a predetermined control according to control from the main control section. Sub-control unit that controls the processing of step 1, a first power supply unit that supplies power to the main control unit, a second power supply unit mounted outside the camera body, the first power supply unit, and the second power supply unit. A voltage determination unit that determines the output voltage value of the power source unit, and one of the first power source unit and the second power source unit selected based on the determination of the voltage determination unit is the A feature is that power is supplied to the slave control unit. According to a seventh aspect of the present invention, in the power supply device for a camera according to the sixth aspect, the voltage determination section outputs the first power source section and the second power source section each time the sub-control section starts operating. It is characterized by judging the voltage value.

[0018]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an external perspective view showing a first embodiment of a camera to which the present invention is applied.
The main switch 47 is a switch that turns on the main power of the camera. The release button 46 is a button that has a two-step push structure and that supplies power to the camera in the first stroke and executes the release sequence in the second stroke.
The external display window 48 is a window for displaying information such as the setting status of the camera. The hot shoe 49 is a connection portion for mounting and controlling a flash device or the like on the outside.

The mode button 50 is used to set the feeding mode, the exposure mode, etc. of the camera, and also serves as a start signal for supplying power to the inside of the camera. The operation button 51 is a button for setting the exposure mode and the like. The camera body 52 and the taking lens 54 are electrically connected by a plurality of electric contacts, and can be separated by the lens attachment / detachment button 53. A device such as a data bag is built in the back cover 55. The in-body battery chamber 56 is a portion for accommodating a battery which is a power source in the camera body 52.

FIG. 2 shows a data back 60 of the camera of FIG.
It is a figure which shows the electrical contact of. When the case back 55 is closed,
The data back 60 and the camera body 52 have an electrical contact 1
It is electrically connected by 8 and 19.

FIG. 3 is a block diagram showing an embodiment of the power supply device for the camera of FIG. 1 and corresponds to the block diagram of FIG. 6 shown in the conventional example. Below, mainly in FIG.
Differences from the conventional power supply device for a camera will be described. The circuit 16 in the data bag 60 transmits / receives a signal to / from the camera body 52 by an electric contact group, but in FIG. 3, only the electric contact groups 18 and 19 related to power feeding are shown. For the battery 15 of the data bag 60, it is preferable to use a sheet-like one so that the storage portion of the battery 15 is not enlarged. Alternatively, when a general battery having a large thickness is used, it is preferable to position the portion projecting by the storage of the battery 15 on the grip of the camera or the like. A battery (not shown) for timing is installed in the circuit 16 of the data bag 60, and its power consumption is extremely small compared with the battery 15. Power is supplied from the battery 15 to the electric circuits other than those for timekeeping.

The switch 22 is a switch which is turned on / off in conjunction with the opening / closing operation of the back cover 55, and is turned on only when the back cover 55 is completely closed. Here, as shown in FIG. 2, in the electrical contacts of the back lid 55, when the back lid 55 is closed, the negative terminal of the battery 15 (the electrical contacts 1
8) is connected first, and the battery 15
The negative terminal (electrical contact 18) is preferably disconnected later. Capacitor 17
Like the conventional example (FIG. 6), functions as a backup capacitor for holding data. The diode 21 is for preventing the battery 15 in the data bag 60 and the battery 7 in the camera body 52 from interfering with each other. Here, the capacitor 17 has a large capacity,
The diode 21 preferably has a small reverse leakage current. By doing this, the data back 6
Even when the power is drawn from 0 (described later), it is possible to prevent the SINK current from becoming large and preventing the data holding voltage of the data back 60 itself from being secured.

The battery check 20 is for monitoring the voltage of the electrical contact 19. Further, in the camera body 52, the electrical contact 19 and the electrical contact 11 are electrically connected via the transistor 23. In this embodiment, the transistors 6 and 23 are N-ch MOS transistors.

Next, the operation of the present invention will be described. FIG. 4 is a flowchart showing an embodiment of power supply control of a power supply device for a camera according to the present invention, and corresponds to FIG. 7 in a conventional example. The processing from the first step C1 to C4 is the same as the processing from step A1 to A4 in FIG.

When the body CPU 1 is activated in step D1, it is determined in next step D2 whether or not the power source activation switch is turned on. When it is on, the process proceeds to step D3, and when it is off, it waits until it is turned on. In step D3,
Battery check is performed. Battery check 8
The voltage state of the battery 7 is constantly monitored, and the battery value obtained by the battery check 8 is sent to the body CPU 1. When the battery value (BC1) is not larger than the predetermined value (BC), the process proceeds to step D16 and the body CPU
No. 1 issues a warning to notify that the battery should be replaced. If the battery value is larger than the predetermined value, step D
4, the DC / DC converter 4 is activated, and a stable voltage is output. Then, the timer count is started in step D5.

In the next step D6, the camera body 52
Side and the taking lens 54 side start communication. The voltage is
Power is supplied to the master CPU 2 via the electrical contacts 12 and 14. Then, in the next step D7, the master CPU
2 enters the operating state, communicates with the body CPU 1, and issues a power supply request so that power is supplied from the electric contact 11 via the electric contact 13.

In the next steps D8 and D9, the battery values BC1 and BC2 of the batteries 7 and 15 are checked, respectively. The body CPU 1 monitors the outputs of the battery check 8 and the battery check 20, and compares the voltage of the battery 7 with the voltage of the battery 15 in the data bag 60. When the battery value BC1 is not larger than the predetermined value BC in step D8, the process proceeds to step D16 to prompt the warning as described above. Further, in step D8, the battery value BC1 is the predetermined value B
When it is larger than C, the routine proceeds to step D9, where the battery value BC2 obtained by the battery check 20 and the battery value BC1 obtained by the battery check 8 are compared. Battery value B
When the battery value BC2 is larger than C1, the process proceeds to step D10, the power supply control transistor 23 is turned on, and power is supplied into the photographing lens 54 via the electrical contact 11.

On the other hand, in step D9, the battery value B
When C2 is not larger than BC1, the process proceeds to step D15, the power supply control transistor 6 is turned on, and the electrical contact 1
Power is supplied to the inside of the taking lens 54 via 1. Here, when the back cover 55 is open, the steps D9 to D
Since the process proceeds to 15, the power feeding control transistor 6 is turned on. After that, the master CPU 2 checks the battery 9
Monitor the voltage of the electrical contact 11 and when the voltage is determined to be above a predetermined value, the power supply control 2 signal is controlled to
/ DC converter 5 is started. The stable output voltage of the DC / DC converter 5 is supplied to the slave CPU 3 to enter the power-on reset state. When a drive circuit start signal (not shown) is input to the slave CPU 3, the drive circuit 10 that is supplied with power via the electrical contact 11 is drive-controlled.

In step D11, it is determined whether or not the power start-up switch is on. If it is on, the process returns to step D5, and if it is not on, the process proceeds to step D12 to determine whether or not the timer count has reached 8 seconds. To be done. When 8 seconds have not elapsed, the process returns to step D11, and when 8 seconds has elapsed, the process proceeds to step D13. Then, the energization of the transistor 6 or 23 is stopped, and the next step D
At 14, the DC / DC converter 5 is turned off.

FIG. 5 is a circuit diagram specifically showing a power supply switching circuit in the power supply device for a camera of the present invention. Batteries 7 and 15 are of 6V voltage. The voltage of the battery 7 is input to the DC / DC converter 4, and the body CPU
Start up by the control of 1 and the boosted 12V voltage is PNP
It is applied to the emitters of the transistors 24 and 27. The DC / DC converter 4 supplies a voltage different from 12 V to other electric circuits, but the description thereof is omitted here.

When power is supplied from the battery 7 to the taking lens 54, the body CPU 1 controls the CTL terminal for controlling the start / stop of the DC / DC converter 4 to control the DC / DC.
The converter 4 is activated and the emitter of the PNP transistor 24 is biased at 12V. Body CPU1 is P4
Is biased to the H level to render the NPN transistor 26 conductive, and the drain and source of the transistor 6 are biased. In this state, when P2 of the body CPU1 is set to H level, the NPN transistor 25 becomes conductive,
Further, the PNP transistor 24 becomes conductive. At this time,
The gate of the transistor 6 is biased to about a little less than 12V, so that the transistor 6 becomes conductive. As a result, power is supplied to the inside of the taking lens 54 via the electrical contact 11.

Next, a case where power is supplied from the battery 15 in the data bag 60 to the taking lens 54 via the camera body 52 will be described. The body CPU 1 controls the CTL terminal to activate the DC / DC converter 4, and biases the emitter of the PNP transistor 27 at 12V. Body C
PU1 biases P3 to the H level, makes the NPN transistor 29 conductive, and brings the drain and source of the transistor 23 into a biased state. When P1 of the body CPU1 is set to the H level in this state, the NPN transistor 28 becomes conductive and the PNP transistor 27 becomes conductive. At this time, the gate of the transistor 23 is almost 1
Biased to less than 2V, resulting in transistor 2
3 conducts. As a result, power is supplied to the inside of the taking lens 54 via the electrical contact 14. The switching of the power feeding route is controlled by the determination of the battery check described above.

In this circuit diagram, NPN transistors 26 and 29 provide a bias between the drain and source of the transistors. Further, the bias between the collector and the emitter of the NPN transistors 26 and 29 is given through the resistors 30 and 31 having a relatively high resistance.
The resistors 32, 34, 37, 39, 41, and 43 are resistors for preventing halfway conduction of the transistor due to a cutoff current. Resistors 33, 35, 36, 38, 44,
And 45 are resistors for limiting the base current of the transistor. The resistors 40 and 42 are resistors for limiting current when the transistor is turned on.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications such as the following are possible within an equivalent range. For example, in the embodiment, the power supply control transistor 6,
Although N-chMOS is used for 23, a P-chMOS can also be used. In this case, the bias polarities are reversed. Even when the battery voltage drops, P-chMO
It suffices to apply a gate voltage such that S can be sufficiently turned on.

[0035]

According to the first aspect of the present invention, the voltage values of the first power source section and the second power source section are determined, and the power is supplied to the actuator from one power source section selected based on the determination. Therefore, it is possible to supply power to the actuator from an appropriate power source. According to the invention of claim 2, the voltage values of the first power supply unit and the second power supply unit are determined, and one of the power supply units selected based on the determination supplies power to the slave control unit. It is possible to supply power to the slave control unit from an appropriate power supply unit. According to the invention of claim 3, the first
Since the voltage values of the power supply unit and the second power supply unit are determined and one of the power supply units selected based on the determination supplies power to the actuator and the sub-control unit, the appropriate power supply unit drives the actuator. Also, power can be supplied to the slave control unit.

According to the fourth aspect of the invention, since the power source of the auxiliary device is the second power source section, the actuator and the slave control section can be used by using the conventional one without adding new parts. Can be powered. According to the invention of claim 5, the power supply unit having the higher power supply capability supplies power to the actuator and the sub-control unit. Therefore, the power supply unit capable of supplying sufficient electric power to the actuator and the sub-control unit. Can be powered. According to the invention of claim 7, the voltage determination unit determines the output voltage values of the first power supply unit and the second power supply unit each time the sub-control unit starts to operate. It can be operated by receiving power from a power supply unit capable of supplying electric power.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a first embodiment of a camera to which the present invention has been applied.

2 is a diagram showing electrical contacts of a data back 60 of the camera of FIG.

3 is a block diagram showing an embodiment of a power supply device of the camera of FIG.

FIG. 4 is a flowchart showing an embodiment of power supply control of a power supply device for a camera according to the present invention.

FIG. 5 is a circuit diagram specifically showing a power supply switching circuit in the power supply device for a camera of the present invention.

FIG. 6 is a block diagram showing an example of a conventional power supply device for a camera.

7 is a flowchart showing an example of power supply control of the power supply device of the camera of FIG.

[Explanation of symbols]

 1 Body CPU 2 Master CPU 3 Slave CPU 4,5 DC / DC converter 6 Transistor 7 Battery 8,9 Battery check 10 Driving circuit 11, 12, 13, 14, 18, 19 Electrical contact 20 Battery check 23 Transistor 52 Camera body 54 Photography lens 60 data back

Claims (7)

[Claims] 1. A power supply device for a camera having a camera body and a taking lens mounted on the camera body, the main controller being provided in the taking lens and performing main control of the taking lens. An actuator for driving an optical system of the taking lens, an electric contact part for electrically connecting the taking lens and the camera body, and an electric contact part provided in the camera body, A first power supply unit that supplies power to the main control unit via an electrical contact unit; a second power supply unit mounted outside the camera body; a first power supply unit and a second power supply unit. A voltage determining unit that determines an output voltage value, and one of the first power source unit and the second power source unit selected based on the determination of the voltage determining unit,
A power supply device for a camera, which supplies power to the actuator. 2. A power supply device for a camera having a camera body and a taking lens mounted on the camera body, the main controller being provided in the taking lens and performing main control of the taking lens. A slave controller provided in the photographing lens, which controls a predetermined process under the control of the main controller; an electrical contact portion which electrically connects the photographing lens and the camera body; A first power supply unit provided inside the body for supplying power to the main control unit via the electrical contact unit; a second power supply unit mounted outside the camera body; A voltage determining unit that determines an output voltage value of the second power source unit, and either the first power source unit or the second power source unit selected based on the determination of the voltage determining unit. One is
A power supply device for a camera, which supplies power to the slave control unit. 3. A power supply device for a camera having a camera body and a photographing lens mounted on the camera body, the main control unit being provided in the photographing lens and performing main control of the photographing lens, An actuator provided in the taking lens for driving an optical system of the taking lens, and a slave control unit provided in the taking lens for controlling the drive of the actuator according to the control from the main control unit. An electric contact part for electrically connecting the taking lens and the camera body, a first power supply part provided in the camera body for supplying power to the main control part via the electric contact part, A voltage determining unit configured to determine an output voltage value of the first power source unit and the second power source unit; and a voltage determining unit configured to determine an output voltage value of the first power source unit and the second power source unit. Either one of the first power source unit is selected based on the determination or the second power supply unit,
A power supply device for a camera, which supplies power to the actuator and the sub-control unit. 4. The power supply device for a camera according to claim 1, further comprising an auxiliary device mounted outside the camera body for performing an auxiliary operation at the time of photographing, The power supply device for a camera is characterized in that the second power supply unit is provided in the auxiliary device and supplies power to the auxiliary device. 5. The power supply device for a camera according to claim 1, wherein one of the first power supply unit and the second power supply unit having a higher power supply capability is a power supply target. A power supply device for a camera, which supplies power to an object. 6. A power supply device for a camera having a camera body and a photographing lens, wherein a main control unit that performs main control of the photographing lens, and predetermined processing is controlled according to control from the main control unit. Sub-control unit, first power supply unit for supplying power to the main control unit, second power supply unit mounted outside the camera body, outputs of the first power supply unit and the second power supply unit A voltage determining unit that determines a voltage value, and one of the first power source unit and the second power source unit selected based on the determination of the voltage determining unit supplies power to the slave control unit. A power supply device for a camera. 7. The power supply device for a camera according to claim 6, wherein the voltage determination unit outputs output voltage values of the first power supply unit and the second power supply unit each time the sub-control unit starts operating. A power supply device for a camera, which is characterized by: