JP2003330087A - Interchangeable lens with solar battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interchangeable lens with a solar battery and a secondary battery and to selectively drive a lens-side actuator with large electric power by detecting the voltages of the both. <P>SOLUTION: The interchangeable lens is provided with the solar battery, the secondary battery, and a means of detecting the voltages of the both and further comprises the actuator which drives various functions of the lens, its driving circuit, and a microcomputer which controls it. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interchangeable lens mounted on a single-lens reflex camera, and more particularly to an interchangeable lens including a solar cell.

[0002]

2. Description of the Related Art Conventional interchangeable lenses for single-lens reflex cameras are equipped with actuators such as a motor for driving a focus lens for automatic focusing and a motor for driving an aperture for automatic focusing. The camera was powered by the battery inside the camera.

In a single-lens reflex camera, the above-mentioned actuators and the like are expected to operate at high speed from the viewpoint of a photo opportunity, but this consumes electric power, so that a battery with a limited capacity in the camera is used. The battery capacity is suddenly exhausted, and frequent battery replacement is required, which naturally limits the usability.

Further, in recent years, a vibration proof function (hereinafter abbreviated as IS function) for automatically correcting a camera shake phenomenon at the time of photographing has been installed. In order to realize this IS function, an actuator for driving the correction lens in the yaw and pitch directions is required, and the power consumption on the lens side further increases accordingly.

As described above, power consumption is increased due to high performance and multi-functionality of the interchangeable lens, and the limited battery capacity in the camera body is becoming insufficient.

In view of this point, the above problem is solved by providing the interchangeable lens side with a solar cell and a secondary battery charged by the solar cell, and supplying the load current on the interchangeable lens side from this secondary battery. A method can be considered. If this structure is adopted, even if the remaining capacity of the secondary battery decreases, the remaining capacity will be restored if it is charged by the solar cell, so replacement is not limited to the limited capacity of the battery inside the camera body. It is possible to improve the function and performance of the lens side.

[0007]

However, such a power supply system also has the following problems.

That is, since the solar cell does not generate power unless there is a certain amount of light, when the interchangeable lens is used for a long period of time in a dark place such as a room, the
The remaining capacity of the secondary battery may decrease, and a large load current may not be supplied.

Further, even when the solar cell is used outdoors from this state to generate electricity, if the amount of electricity generated is less than a predetermined value, the required load current of the interchangeable lens cannot be satisfied. It is possible.

As described above, even if the interchangeable lens side is provided with the solar cell and the secondary battery structure charged by the solar cell, there is a problem in that the power required by the interchangeable lens cannot always be supplied.

[0011]

SUMMARY OF THE INVENTION The present invention was devised in view of this point, and the gist of the present invention is an interchangeable lens equipped with a solar cell and a secondary battery charged from the solar cell. A detecting means for detecting the generated voltage of the solar cell and the charging voltage of the secondary battery is provided, and means for determining the driving load power on the interchangeable lens side is provided by the detection output.

More specifically, the interchangeable lens has a microcomputer, and the microcomputer transfers the output result of the detection means to the microcomputer on the camera body side by communication, and the microcomputer on the camera side uses the transferred contents to determine the interchangeable lens. The control method of each actuator is determined.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to Examples.

FIG. 1 is an electric circuit diagram showing a first embodiment of the present invention.

Reference numeral 10 in the figure denotes a plurality of solar cells connected in series, which are arranged on the outer surface of the interchangeable lens. The following 18 are all constituent elements arranged on the interchangeable lens side. 1
2 is a secondary battery, 11 is a diode for preventing backflow connected between the solar cell 10 and the secondary battery 12, and 13 is a secondary battery 1
Secondary battery 1 with Zener diode connected in parallel with 2
Prevent overcharge of 2.

Reference numeral 14 denotes a voltage detection circuit, which is a microcomputer 1 described later.
The voltage from the solar cell 10 and the secondary battery 12 is level-converted by the signal from the circuit 6 and alternately output to the A / D converter 15 in time series. Reference numeral 15 is an A / D converter, and 16 is a microcomputer.

Reference numeral 17 is a DC motor for driving a focus lens (not shown), and 18 is a drive circuit for PWM driving the DC motor under the control of the microcomputer 16. A to D are mount sections on the interchangeable lens side, and section A is a ground terminal,
The segment B is the clock input terminal CLK of the lens microcomputer 16
Are connected to each. Further, the section C and the section D are respectively connected to the data input terminal DCL and the data output terminal DLC terminal of the lens microcomputer 16.

Next, the constituent requirements of the camera body will be described.
Reference numeral 20 is a primary battery in the camera body, 21 is a diode for preventing backflow, and 22 is a power supply capacitor. Reference numeral 23 is a camera microcomputer, 24 is a SW1 switch that is closed by the first stroke of the shutter button of the camera, and 25 is a SW2 switch that is closed by the second stroke, which are respectively connected to the input ports of the camera microcomputer 23. 26 is a battery 20
The switching circuit connected to the camera microcomputer 2
The output port of 3 is on / off controlled.

A to f are mount sections in the camera body,
The intercept a is connected to the ground terminal, and the intercept b is connected to the clock output terminal of the camera microcomputer 23. Further, the intercept c and the intercept d are connected to the data output terminal and the data input terminal of the camera microcomputer 23, respectively.

The intercept e and the intercept f are the VDD power supply of the power supply capacitor 22 and the VBA of the switching circuit 26, respectively.
It is connected to the T power supply.

When the interchangeable lens is mounted on the camera body, the mount sections A to D on the interchangeable lens side are connected to the mount sections a to d of the camera body, respectively, and the lens microcomputer 1
6 and the camera microcomputer 23 are ready to communicate with each other.

The operation of this embodiment configured as described above will be described with reference to the flowchart of FIG.

In FIG. 1, the output voltage of the solar cell 10 is SV, 2
The charging voltage of the secondary battery 12 is named RV. As described above, the voltages SV and RV are detected by the voltage detection circuit 14.
The signals are alternately sent to the A / D conversion circuit 15, A / D converted, and taken into the microcomputer 16. STEP100: Start STEP101: LPS signal (LARG in lens microcomputer
E POWER SUPPY) is initialized to "0".

STEP 102: It is judged whether or not the output voltage SV of the solar cell 10 is 0 V (that is, whether or not the solar cell generates power). If it is 0 V, the process proceeds to STEP 107. If not, the process proceeds to STEP 103.

STEP 103: It is determined whether the output voltage SV of the solar cell 10 is higher than a predetermined voltage V1 (that is, whether the power generated from the solar cell is large). SV is V1
If it is larger, the process proceeds to STEP 104. If not, the process proceeds to STEP 105.

STEP 104: The lens microcomputer 16 sets the LPS signal to "1" and shifts to STEP 107.

STEP 105: It is determined whether the output voltage RV of the secondary battery 12 is higher than a predetermined voltage V2 (that is, whether the charged capacity of the secondary battery is large). R
If V is larger than V2, the process proceeds to STEP 106, and if not, the process proceeds to STEP 107.

STEP 106: The lens microcomputer 16 sets the LPS signal to "1" and shifts to STEP 107.

STEP 107: The lens microcomputer 16 transfers the LPS signal to the camera microcomputer 23 by communication.

The following is the operation of the microcomputer 23 on the camera side.

STEP 108: The camera microcomputer 23 initializes the PWM signal (POWER WIDTH MODULATION signal) in the camera to the S (SMALL) state with a low duty ratio.

STEP 109: The camera microcomputer 23 determines from the detection result of a focus detection circuit (not shown) or the like whether or not the focus detection operation by the high speed drive of the focus lens of the interchangeable lens is possible at present. If it is possible, STEP1
10. If not, move to STEP 112 respectively.

STEP 110: The LPS signal is "1".
Determine whether or not. If it is "1", the process proceeds to STEP111. If not, the process proceeds to STEP112.

STEP 111: The camera microcomputer 23 sets the PWM signal (POWER WIDTH MODULATION signal) in the camera to the L (LARGE) state with a high duty ratio.

STEP 112: The camera microcomputer 23 transfers the PWM signal to the lens microcomputer 16 by communication.

The lens microcomputer 16 is a camera microcomputer 23.
When receiving the drive command signal of the focus lens from the above, the transferred PWM signal is seen, and if it is in the L state, the duty ratio of the PWM drive of the DC motor 17 is set high to drive at high speed, and vice versa. If S is in the S state, the duty ratio of the PWM drive of the DC motor 17 is set low and the DC motor 17 is driven at a low speed.

The above LPS signal (LARGE POWER SUPPY)
The selection table of is shown in FIG. This table shows L for the situation of the output voltage SV of the solar cell 10 and the charging voltage RV of the secondary cell 12.
It shows what the PS signal looks like. "1" represents a state in which LPS (LARGE POWER SUPPY) is possible, and "1" represents a state in which it is impossible.

The LPS signal is set to "1" when the output voltage SV of the solar cell is larger than the predetermined value V1 and when the output voltage SV of the solar cell is not 0 but smaller than the predetermined value V1. The charging voltage RV of the secondary battery is a predetermined value V
If it is greater than 2. That is, when the amount of power generated by the solar cell is sufficiently large, it is determined that the solar cell alone can supply a sufficiently large amount of power to the actuator in the lens regardless of the charge capacity of the secondary battery, and the LPS signal is output. If set to "1" and the amount of power generated by the solar cell is not too large, but the charge capacity of the secondary battery is sufficiently large, supplying power from both will be sufficiently large for the actuator in the lens. The LPS signal is set to "1" when it is determined that power can be supplied.

On the other hand, when the amount of power generated by the solar cell is not so large and the charge capacity of the secondary battery is small, even if power is supplied from both of them, a large amount of power cannot be supplied to the actuator in the lens. Judge and set LPS signal to "0"
Set to. Further, when there is no power generated by the solar cell, it is determined that large power cannot be supplied to the actuator in the lens as necessary regardless of the charge capacity of the secondary battery, and the LPS signal is set to "0".

In the first embodiment, this LPS signal is "1".
In addition, when the camera body determines that the focus lens can be driven at high speed, the DC motor 17 is driven at high speed.

Next, an electric circuit diagram of the second embodiment of the present invention is shown in FIG.

In the figure, the same numerals as those in FIG. 1 indicate the same constituent elements, and the explanation thereof will be omitted.

In this embodiment, an ultrasonic motor (hereinafter referred to as USM) is used as an actuator for driving the focus lens.

In the figure, reference numeral 30 is a DC / DC converter which boosts the voltage of the secondary battery 12 and serves as a USM drive power source. The DC / DC converter 30 can be switched between a high voltage output and a low voltage output under the control of the microcomputer 16. Three
Reference numeral 1 is a USM drive circuit, and 32 is a USM.

In the present embodiment, the voltage detection circuit 14, A /
As a power source for the D converter 15 and the lens microcomputer 16, 2
The secondary battery 12 is not used, but the VDD power source of the camera body is used. Therefore, the section E is provided on the mount on the lens side,
When the interchangeable lens is attached to the camera body, it is connected to the section e of the camera mount.

The operation of the second embodiment configured as described above will be described with reference to the flowchart of FIG. 5, but since the flowchart of FIG. 5 is almost the same as the flowchart of FIG. 4, only different points will be described.

The camera microcomputer 23 is D in STEP208.
The C / DC signal (output voltage of the lens DC / DC 30) is set to S (low output state).

The camera microcomputer 23 determines from the detection result of a focus detection circuit (not shown) or the like whether or not the focus detection operation can be currently performed at a high speed drive of the focus lens of the interchangeable lens. If it is determined to be possible, the process proceeds to STEP 210, and if not, the process proceeds to STEP 212.

Further, in STEP 210, the LPS signal is "1".
Determine whether or not. In the case of "1", the process proceeds to STEP 211 and the DC / DC signal is set to L (high output state). In step 212, the DC / DC signal is transferred to the lens side.

The lens microcomputer 16 is the camera microcomputer 23.
When the focus lens drive command signal is received from the device, the transferred DC / DC signal is viewed, and if it is in the L state, the output voltage of the DC / DC converter 30 is set high to drive the USM at high speed. . Conversely, the DC / DC signal is S
In the state, the output voltage of the DC / DC converter 30 is set low and the USM is driven at a low speed.

In the second embodiment, the LPS signal is "1",
In addition, when the camera body determines that the focus lens can be driven at high speed, the USM 32 is driven at high speed. In the above embodiments, the DC motor for driving the focus lens and the USM are exemplified as the actuators in the lens, but the present invention is not limited to these, and various kinds for driving the IS correction optical system and the zoom drive. Needless to say, it can be applied to the actuator of.

Further, in the above embodiment, the LPS signal is set according to the output voltage of the solar cell and the charging voltage of the secondary cell according to the selection table of FIG. 3, but the present invention is not limited to this. Instead, it can be flexibly set according to the characteristics of the solar cell and the performance of the secondary battery.

[0053]

As described in detail based on the above embodiments, the present invention is an interchangeable lens equipped with a solar cell and a secondary battery charged from the solar cell, and further, the power generation voltage of the solar cell and the Since the detection means for detecting the charging voltage of the secondary battery is provided, and the means for determining the drive load power on the interchangeable lens side is provided by the detection output, the power supply system can properly set the state capable of driving a large current load. It is possible to supply a large current to the actuator on the lens side,
The effect is great.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a first embodiment of the present invention.

FIG. 2 is an electric circuit diagram showing a second embodiment of the present invention.

FIG. 3 LPS signal selection table

FIG. 4 is a flowchart showing a first embodiment of the present invention.

FIG. 5 is a flowchart showing a second embodiment of the present invention.

[Explanation of symbols]

10 solar cells 13 secondary battery 14 Voltage detection circuit 15 A / D converter 16 lens microcomputer 17 DC motor 23 Camera microcomputer 32 USM

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02B 7/08 G03B 7/26 5H030 G03B 7/26 H01M 10/48 P H01L 31/04 H02J 7/35 K H01M 10/48 G02B 7/04 E H02J 7/35 H01L 31/04 Q F term (reference) 2H002 BC02 BC06 2H044 AE01 AE07 BE02 DA01 DC00 2H101 EE08 EE13 EE21 EE75 5F051 BA05 JA07 JA17 JA20 KA02 KA03 5G06 A05 06G05 A06 06A05 AS11 FF43

Claims (6)

[Claims] 1. A camera system including a solar cell, a secondary battery charged from the solar cell, and a camera body to which an interchangeable lens having an actuator for driving various functions of the lens can be attached, further comprising: an output voltage of the solar cell; Two
It is characterized in that it has a voltage detecting means for detecting the charging voltage of the secondary battery, and has a selecting means for selecting the drive power of the actuator according to the output of the voltage detecting means. 2. The camera system according to claim 1, wherein the selecting means includes a microcomputer of a camera body and a microcomputer of an interchangeable lens. 3. The camera system according to claim 1, wherein the voltage detecting means includes an A / D converter. 4. The camera system according to claim 1, wherein when the output voltage of the solar cell is higher than a predetermined value, the selecting means sets the drive power of the actuator without depending on the charging voltage of the secondary battery. It is characterized by selecting high power. 5. The camera system according to claim 1, wherein when there is no output voltage of the solar cell, the selecting means does not depend on the charging voltage of the secondary battery, and the selecting means outputs a small electric power as driving power of the actuator. It is characterized by selecting. 6. The camera system according to claim 1, wherein when the output voltage of the solar cell is lower than a predetermined value and the charging voltage of the secondary battery is higher than a predetermined value, the selecting means drives the actuator. Is characterized by selecting a large power.