JP2002014394A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a camera capable of making plural stroboscopic flashing parts selectively flash using one or one system main capacitor, and permitting downsizing and cost reduction of the stroboscopic device. SOLUTION: The main capacitor 58 is charged with electric energy for stroboscopic flashing by a charging circuit. An MPU 48 controls to turn on an IGBT 70 at the time of normally photographing, and then turns on a thyristor 74, to operate a trigger circuit 54. Thus, the electric energy is supplied to a 1st xenon lamp 21 from the main capacitor 58, and the 1st xenon lamp 21 flashes. On the other hand, the MPU 48 controls to turn on the IGBT 72 at the time of macro-photographing, and then turns on the thyristor 74, to operate the trigger circuit 54. Thus, the electric energy is supplied in the 2nd xenon lamp 25 from the main capacitor 58, and the 2nd xenon lamp 25 flashes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, to a camera having a plurality of strobe light emitting units.

[0002]

2. Description of the Related Art Recently, a camera having two strobe light emitting units is commercially available. One strobe light emitting unit emits light on a telephoto side, and the other strobe light emitting unit emits light on a wide side.

A camera having a plurality of strobe light emitting units of this type has a plurality of capacitors (hereinafter, referred to as "main capacitors") for storing light emission energy for each strobe light emitting unit independently.

[0004]

However, a camera in which a plurality of main condensers are separately provided has a problem in that the size and cost of the camera are increased.

The present invention has been made in view of such circumstances, and it is possible to selectively emit light from a plurality of strobe light emitting portions using one or one system of a main capacitor.
An object of the present invention is to provide a camera capable of reducing the size and cost of a strobe device.

[0006]

According to a first aspect of the present invention, there is provided a camera, comprising: a plurality of strobe light emitting portions; one or one main capacitor; and a charging device for charging the main capacitor. Means for selectively supplying the electric energy charged in the main capacitor to the plurality of strobe light emitting units in accordance with distance information to the subject or setting of an imaging distance of the camera, and selectively controlling the plurality of strobe light emitting units. And a strobe control means for emitting light.

According to the first aspect of the present invention, one or one system of the main capacitor is shared by a plurality of strobe light-emitting portions, thereby making it possible to reduce the size and cost of the strobe device. I have.

The strobe control means supplies a plurality of switching elements inserted in series to the plurality of strobe light emitting portions, respectively, and supplies a trigger signal to each of the plurality of strobe light emitting portions. And a control means for individually turning on / off the plurality of switching elements and operating the trigger means. The one trigger means is shared by a plurality of strobe light emitting units, thereby enabling cost reduction.

The strobe control means supplies one switching element connected in series to the plurality of strobe light emitting portions and a trigger signal to each of the plurality of strobe light emitting portions. It is characterized by having a plurality of trigger means, and a control means for controlling ON / OFF of the switching element and operating the plurality of trigger means individually. The one switching element is shared by a plurality of strobe light emitting parts, thereby enabling cost reduction.

The switching element is an insulated gate bipolar transistor as described in claim 4 of the present application.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the camera according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a front perspective view of a camera 10 and FIG.
Shows a rear perspective view thereof. As shown in FIG. 1, a photographing lens barrel 14 having a zoom function is disposed substantially at the center of the front surface of the camera body 12. An object window 16 of the optical finder is arranged above the taking lens barrel 14, and windows 18 having an autofocus sensor and an exposure sensor are arranged on both sides of the object window 16.

At the upper right corner of the front surface of the camera body 12, a first strobe light emitting unit 20 used during normal photographing is disposed. On the photographing lens barrel 14, a second strobe light used during macro photographing is provided. A light emitting unit 24 is provided. That is, the first strobe light emitting section 20 is disposed at a position as far away from the taking lens 22 as possible in order to reduce the red-eye phenomenon at the time of strobe shooting. Further, since the second strobe light emitting unit 24 is provided on the front surface of the taking lens barrel 14, it is possible to efficiently irradiate the subject during macro shooting.

As is apparent from FIG. 1, the second strobe light-emitting section 24 is smaller than the first strobe light-emitting section 20 because it must be incorporated into the lens barrel 14, and as a result, the second strobe light-emitting section 20 is formed. The second xenon tube 25 of the unit 24 (see FIG. 4) is connected to the first xenon tube 21 of the first strobe light emitting unit 20.
Smaller arc lengths are used.

A grip portion 26 is formed on the left side of the front surface of the camera body 12, and a shutter button 2 operated by the photographer's right hand is provided on the left side of the top surface of the camera body 12.
8 are provided.

The camera 10 has a photographing distance of 1 m to に は in the normal photographing mode, and an unillustrated lens provided on the photographing lens barrel 14 when the normal photographing mode is changed to the macro mode. Is moved to a predetermined macro shooting position, and the shooting distance at that time is set to, for example, 60 cm. Further, the zoom lens (not shown) provided on the taking lens barrel 14 is moved to the tele end position when the mode is changed to the macro mode. Thus, the subject can be photographed at a high magnification. The moving position of the zoom lens in the macro mode is not limited to the tele end position, but may be moved to a desired position of the zoom stage.

As shown in FIG. 2, an eyepiece window 30 of an optical finder is disposed at the upper center of the rear surface of the camera body 12.
A zoom lever 32 is provided at the upper right corner on the back of the camera body 12.
Are provided so as to swing right and left. By operating the zoom lever 32 left and right, a zoom lens drive motor (not shown) is driven, and the zoom lens moves back and forth along the photographing optical axis. Thereby, zooming is performed.

A rectangular liquid crystal panel 34 is arranged below the eyepiece window 30. The liquid crystal panel 34 displays the number of film shots, the remaining battery level, a shooting mode indicating auto and red-eye prohibition, and the like, and a macro mark indicating macro shooting. On the left side of the liquid crystal panel 34, there are provided a power ON / OFF button 36 of the camera 10, a button 38 for selecting the shooting mode, and a switching button 40 for switching between normal shooting and macro shooting.

When the switching button 40 is operated to switch to the normal photographing side, the photographing distance is set to 1 m to ∞ as described above. When the switching button 40 is operated to switch from the normal shooting side to the macro shooting side, the shooting distance is set to 60 cm as described above. Reference numeral 42 denotes a lever for opening the film cartridge lid 44.

FIG. 3 is a block diagram showing a control system of the camera according to the present invention.

As shown in FIG. 3, a microprocessor unit (MPU) 48 for controlling the entire camera 10 includes signals from various operation switches such as a shutter button 28, a forced rewind switch 29, a strobe OFF switch 31, and the like. AF unit 5 having an autofocus sensor
Subject distance information from 0, subject brightness information from the AE unit 52 having an exposure sensor, remaining battery information from the battery check unit 11, a perforation detection signal from the perforation sensor 13, a reset signal from the reset IC, and the like are added. It has become.

The shutter button 28 is turned on when pressed halfway
When the switch SP1 is turned on, the MPU 48 controls the aperture based on the subject brightness information from the AE unit 52, and sets the shutter time. AE control is performed to determine the time, and the AF unit 50
A for focusing based on subject distance information from
Perform F control. When the switch SP2 is turned on,
The MPU 48 causes the photographing to be performed. That is, based on the determined shutter time, the shutter unit 33 is controlled and the strobe device 46 is controlled. The details of the control of the strobe device 46 will be described later.

When the photographing of one frame is completed, the MPU 48 drives the feed motor 37 forward through the motor driver 35 to start feeding one frame of the film, and a perforation detection signal is output from the film perforation sensor 13. When added (that is, when one frame feed is detected), the film feeding is stopped. In addition, MPU48
Drives the feed motor 37 through the motor driver 35 in the reverse direction when photographing of all frames is completed or when the forced rewind switch 29 is turned on. As a result, the photographic film is reversely fed and rewound into the film cartridge.

An electrically erasable programmable ROM (E
Various parameters and data related to camera control and data processed by the MPU 48 are stored and stored in the EPROM 17 so that they do not volatilize even when the battery is exhausted or pulled out for a long time.

FIG. 4 is a circuit diagram showing a first embodiment of the strobe device 46 shown in FIG.

As shown in FIG. 4, the strobe device 46 includes a first xenon tube 21 of the first strobe light emitting section 20, a second xenon tube 25 of the second strobe light emitting section 24, and a trigger transformer 53.
A trigger circuit 54, a charging circuit 56, a main capacitor 58, a battery 62 as a power supply, transistors 64, 66, 68 as switching elements, field effect transistors (FETs) 65, 67, an insulated gate bipolar transistor (IGBT) 70, 72 and thyristor 7
4 and so on. In this embodiment, the number of the main capacitors 58 is one. However, a single system in which a plurality of capacitors are connected in parallel may be used.

The MPU 48 includes the transistors 64 and F
The ET 65, the transistor 66, the FET 67, and the transistor 68 are individually ON / OFF controlled.
That is, when the output port FLASH1 of the MPU 48 is set to L level, the transistor 64 is turned on and the FET 65 is turned on.
Is turned off, whereby the IGBT 70 is turned on.
Conversely, when the output port FLASH1 of the MPU 48 is set to the H level, the transistor 64 is turned off and the FET 6
5 is turned on, thereby turning off the IGBT 70 instantaneously.
Is done. Similarly, when the output port FLASH2 of the MPU 48 is set to the L level, the transistor 66 is turned on and the FET 67 is turned off, whereby the IGBT 72 is turned off.
N. Conversely, when the output port FLASH2 of the MPU 48 is set to the H level, the transistor 66 is turned off and the FET 67 is turned on, whereby the IGBT 72 is turned off instantaneously.

The output port FLASH3 of the MPU 48 is set to L
When the level is set, the transistor 68 is turned on and the thyristor 74 is turned on. As a result, a current flows through the trigger transformer 53, and a high voltage of several kv is applied to the trigger electrode 20A of the first strobe light emitting unit 20 and the trigger electrode 24A of the second strobe light emitting unit 24.

When the power of the camera 10 is turned on, the strobe device 46 boosts the voltage of the battery 62 via the charging circuit 56, and charges the main capacitor 58 with strobe electric energy.

When the thyristor 74 is turned on while the IGBT 70 is turned on and a high voltage is applied from the trigger circuit 54 to the trigger electrode 20A of the first strobe light emitting section 20, the first strobe light emitting section 20 has Arc discharge occurs between the poles of one xenon tube 21 and the xenon tube 21 emits light. On the other hand, when the thyristor 74 is turned on while the IGBT 72 is turned on and a high voltage is applied to the trigger electrode 24A of the second strobe light emitting unit 24 from the trigger circuit 54, the second xenon tube of the second strobe light emitting unit 24 is turned on. 25
Arc discharge occurs between the two electrodes, and the xenon tube 25 emits light.

Here, when the xenon tube 21 emits light, the resistor 75 and the first xenon tube 2
1 and the current flows through the IGBT 70, and when the second xenon tube 25 emits light, the current flows through the resistors 75 and 77, the second xenon tube 25, and the IGBT 72.

As described above, the first xenon tube 21 and the second xenon tube 25 have different arc lengths, and the first xenon tube 21 and the second xenon tube 2 have different arc lengths.
In order to cause the second xenon tube 25 having a short arc length to emit light by using the same main condenser 58, it is necessary to take measures for light emission durability. Therefore, the first xenon tube 2
The resistance provided in the line for emitting light from the second xenon tube 25 is made larger than the resistance provided in the line for emitting light 1 to increase the durability by suppressing the inrush current. In this embodiment, the resistances 75 and 77 are provided in the line for emitting the second xenon tube 25, and the resistance becomes larger than the resistance 75 in the line for emitting the first xenon tube 21 by the resistance 77. Like that.

The resistors 75 and 77 are wire-shaped so-called resistance wires whose resistance value increases in proportion to the length of the wires, because of their rated power. Current flowing through the first xenon tube 2
By making a configuration that passes through the resistor 75 in one line,
An increase in installation space can be minimized. Incidentally, the total resistance value of the resistors 75 and 77 is a resistance value in the range of 5 to 100% of the tube resistance at the time of light emission of the second xenon tube 25, so that the tube current flowing through the second xenon tube 25 can be sufficiently increased. We can control it.

Next, the operation of the camera according to the present invention will be described with reference to the flowchart shown in FIG.

First, when the film cartridge lid 44 is opened and the film cartridge is loaded into the camera, the film feeding system is controlled, the film is automatically sent out from the film cartridge, and the film tip is moved to the film winding shaft. The film is wound and the first frame of the film is set at a predetermined exposure position (step S10).

Subsequently, charging of the main capacitor 58 is controlled (step S12), and the shutter button 2 is controlled.
8 is half-pressed and the switch SP1 is turned on (step S14), and the forced rewind switch 29 is
It is determined whether or not N has been performed (step S16).

If it is determined in step S16 that the forced rewind switch 29 has been turned on, step S34 is reached.
Then, the film is reversely fed and rewound into the film cartridge. On the other hand, if it is determined in step S14 that the switch SP1 has been turned ON, battery check control, AE control, and AF control for photographing preparation are performed (steps S18, S20, S22).

When the photographing preparation is completed, it is determined again whether or not the switch SP1 has been turned ON (step S2).
4) When the switch SP1 is turned off, step S1
Returning to step 2, if the switch SP1 is ON, the process proceeds to step S26. In step S26, it is determined whether or not the shutter button 28 has been fully pressed to turn on the switch SP2. If the switch SP2 has not been turned on, the process returns to step S24. Perform (Step S28). The details of this shooting control will be described later.

When the photographing control in step S28 is completed, film feed control for feeding the film one frame is performed (step S30), and thereafter, it is determined whether or not photographing of all the frames of the film has been completed. (Step S3
2). If the shooting of all the frames has not been completed, the process returns to step S12 to perform the shooting of the next frame. If the shooting of all the frames has been completed, the film is reversely fed and wound into the film cartridge. Return (step S34).

Next, details of the photographing control in step S28 in FIG. 5 will be described with reference to the flowchart shown in FIG.

First, the strobe OFF switch 31 is turned ON.
It is determined whether or not the operation has been performed (step S50). If the strobe OFF switch 31 is ON, the flag A is set to 0 to inhibit strobe light emission (step S52). On the other hand, strobe OFF switch 3
If 1 is OFF, it is determined whether or not the subject distance measured by the AF unit 50 is larger than the macro shooting determination distance X (constant) (step S54).

If the subject distance is larger than the distance X, the flag A is set to 1 in order to determine that the photographing is the normal photographing and to perform the strobe light emission for the normal photographing (step S5).
6) If the subject distance is equal to or less than the distance X, the flag A is set to 2 in order to determine that the macro shooting is to be performed and to cause the strobe light emission for the macro shooting to be performed (step S58). still,
In this flowchart, the normal shooting and the macro shooting are determined based on whether or not the subject distance is greater than the distance X. However, as described above, the normal shooting and the macro shooting are performed in accordance with the switching position of the switching button 40. May be determined.

Next, the flash emission time is calculated according to the subject distance and whether the shooting is normal or macro, and
The shutter time is calculated (steps S60 and S6).
2). It should be noted that the light source is first depending on whether normal shooting or macro shooting.
Since it changes to the xenon tube 21 or the second xenon tube 25,
It is necessary to control the flash emission time (light amount control) according to whether the shooting is normal shooting or macro shooting.

Subsequently, the shutter opening operation is started (step S64), and it is determined whether the flag A is set to 1, 2, or 0 (step S6).
6, S68). Here, when A = 1, the MPU 48
Output port FLASH1 is set to L level (step S68). As a result, the IGBT 70 is turned on, and the first
The xenon tube 21 can emit light (see FIG. 4). Similarly, when A = 2, the output port FLASH2 of the MPU 48
Is set to the L level (step S72). As a result, the IGBT 72 is turned on, and the second xenon tube 25 can emit light. On the other hand, if A ≠ 1,2 (that is, A = 0), the process jumps to step S80 because the strobe light emission is prohibited.

At step S68 or S72, the first
When the xenon tube 21 or the second xenon tube 25 becomes ready to emit light, it is determined whether or not the shutter has been fully opened (step S74). When the shutter is fully opened, the output port FLASH3 of the MPU 48 is set to L level (step S76). As a result, the thyristor 74 is turned on, and the trigger circuit 54 supplies the first strobe light emitting unit 2
A high voltage is applied to the zero trigger electrode 20A and the trigger electrode 24A of the second strobe light emitting unit 24, and either the first xenon tube 21 or the second xenon tube 25 in the light-emitted state emits light.

Thereafter, it is determined whether or not the light emission time obtained in step S60 has elapsed since the start of the flash emission (step S78).
The output ports FLASH1, FLASH1, FLASH2, and FLASH3 of U48 are set to H level, and the flag A is set to 0 (step S8).
0). This stops the flash emission.

Next, it is determined whether or not the shutter time obtained in step S62 has elapsed since the shutter was opened (step S82). When the shutter time has elapsed, the shutter is closed (step S84). Thus, the shooting control ends.

FIG. 7 is a circuit diagram showing a second embodiment of the strobe device 46 shown in FIG. In FIG. 7, parts that are the same as those shown in the circuit diagram of FIG. 4 are given the same reference numerals, and detailed descriptions thereof will be omitted.

Comparing the strobe circuits of FIGS. 4 and 7, the strobe circuit of FIG.
Independent IGBT 70 for xenon tube 25
And an IGBT 72 are provided. On the other hand, a common trigger circuit 54 is provided for the first xenon tube 21 and the second xenon tube 25, but the strobe circuit of FIG. A common IGBT 71 is provided for the second xenon tube 25, while the first xenon tube 2
The difference is that trigger circuits 54A and 54B are provided independently for the first and second xenon tubes 25, respectively.

In the circuit shown in FIG. 7, when the output port FLASH3 of the MPU 48 is set to L level, the transistor 78
Is turned on and the FET 79 is turned off, whereby the IGBT 71 is turned on. Conversely, when the output port FLASH3 of the MPU 48 is set to H level, the transistor 78
Is turned off and the FET 79 is turned on, whereby the IGBT 71 is turned off instantaneously.

The output port FLASH1 of the MPU 48 is set to L level.
When the level is set to the level, the transistor 68A is turned on and the thyristor 74A is turned on. As a result, the trigger circuit 54A operates, and a high voltage is applied to the trigger electrode 20A of the first strobe light emitting section 20. Similarly, when the output port FLASH2 of the MPU 48 is set to L level, the transistor 6
8B is turned on, and the thyristor 74B is turned on. As a result, the trigger circuit 54B operates, and a high voltage is applied to the trigger electrode 24A of the second strobe light emitting unit 24.

Therefore, when the IGBT 71 is turned on, the thyristor 74A is turned on, and the trigger circuit 54A outputs the trigger electrode 2 of the first strobe light emitting section 20.
When a high voltage is applied to 0 A, the first strobe light emitting section 20
Arc discharge occurs between the poles of the first xenon tube 21, and the xenon tube 21 emits light. On the other hand, when the thyristor 74B is turned on and a high voltage is applied from the trigger circuit 54B to the trigger electrode 24A of the second strobe light emitting unit 24, arc discharge occurs between the two electrodes of the second xenon tube 25 of the second strobe light emitting unit 24. , The xenon tube 25 emits light.

FIG. 8 is a flow chart showing the procedure of photographing control corresponding to the flash circuit shown in FIG. The same steps as those in the flowchart shown in FIG. 6 are denoted by the same step numbers, and detailed description thereof will be omitted.

In FIG. 8, when the shutter opening operation is started (step S64), the output port FLASH3 of the MPU 48 is set to L level (step S10).
0). As a result, the IGBT 71 is turned ON, and the first xenon tube 21 and the second xenon tube 25 can emit light (see FIG. 7).

Thereafter, it is determined whether or not the shutter has been fully opened (step S102). When the shutter is fully opened, it is determined whether the flag A is set to 1, 2, or 0 (steps S104 and S10).
6).

If A = 1, the output port FLASH1 of the MPU 48 is set to L level (step S).
108). As a result, the thyristor 74A is turned on, a high voltage is applied from the trigger circuit 54A to the trigger electrode 20A of the first strobe light emitting section 20, and only the first xenon tube 21 in the light emitting state emits light.

Similarly, when A = 2, the output port FLASH2 of the MPU 48 is set to L level (step S).
110). As a result, the thyristor 74B is turned on, a high voltage is applied from the trigger circuit 54B to the trigger electrode 24A of the second strobe light emitting unit 24, and only the second xenon tube 25 in the light emitting state emits light.

[0058]

As described above, according to the camera of the present invention, a plurality of strobe light emitting portions having different arc lengths can be selectively made to emit light by using one or one system of a main capacitor. This makes it possible to reduce the size and cost of the strobe device. In particular, the inrush current from the main capacitor into the strobe light emitting portion having a short arc length can be reduced by the resistance in the line to the strobe light emitting portion, and the strobe light having a long arc length can be used. The resistance of the strobe light emitting section having a short arc length can be improved at low cost by suppressing the resistance by increasing the resistance in the line of the section.

[Brief description of the drawings]

FIG. 1 is a front perspective view of a camera to which the present invention is applied.

FIG. 2 is a perspective view of the camera of FIG. 1 as viewed from the back;

FIG. 3 is a block diagram showing a control system of the camera according to the present invention.

FIG. 4 is a circuit diagram showing a first embodiment of a strobe device.

FIG. 5 is a flowchart used to explain an outline of the entire processing content of the camera according to the present invention;

FIG. 6 is a flowchart showing the procedure of shooting control corresponding to the flash circuit shown in FIG. 4;

FIG. 7 is a circuit diagram showing a second embodiment of a strobe device.

FIG. 8 is a flowchart showing a procedure of shooting control corresponding to the flash circuit shown in FIG. 7;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Camera, 14 ... Photographing lens barrel, 20 ... 1st strobe light-emitting part, 21 ... 1st xenon tube, 22 ... Photographing lens, 24 ... 2nd strobe light-emitting part, 25 ... 2nd xenon tube, 46 ... Strobe device , 48 MPU, 50 AF unit, 52 AE unit, 54, 54A, 54B
Trigger circuit, 56 ... charging circuit, 58 ... main capacitor, 70, 71, 72 ... IGBT (insulated gate bipolar transistor), 74, 74A, 74B ... thyristor, 75, 77 ... resistor

Claims (4)

[Claims] 1. A plurality of strobe light emitting portions, one or one main capacitor, charging means for charging the main capacitor, and a main capacitor according to distance information to a subject or setting of a photographing distance of a camera. A flash control unit for selectively supplying the charged electric energy to the plurality of strobe light-emitting units to selectively emit light from the plurality of strobe light-emitting units. 2. The strobe control unit includes a plurality of switching elements inserted in series with the plurality of strobe light emitting units, and one trigger unit that supplies a trigger signal to each of the plurality of strobe light emitting units. 2. The camera according to claim 1, further comprising control means for individually turning on / off the plurality of switching elements and operating the trigger means. 3. The strobe control unit includes: a switching element connected in series to the plurality of strobe light emitting units; a plurality of trigger units each supplying a trigger signal to each of the plurality of strobe light emitting units; 2. The camera according to claim 1, further comprising control means for controlling ON / OFF of said switching element and individually operating said plurality of trigger means. 4. The camera according to claim 2, wherein said switching element is an insulated gate bipolar transistor.