JP2005326565A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance the convenience of a camera. <P>SOLUTION: The camera is equipped with an illumination part 6 equipped with a lamp 6-2, and a control circuit 2 switching a 1st mode in which the lamp 6-2 is driven by 1st driving ability and a 2nd mode in which the lamp 6-2 is driven by 2nd driving ability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical apparatus such as a camera capable of red-eye alleviation illumination.

  In recent years, optical devices such as cameras and digital cameras generally have a built-in strobe to enable photographing at night and indoors. In flash photography, a “red-eye phenomenon” occurs in which a person's subject is irradiated with a strobe, the retina and the like are reflected, and the eye portion is exposed red on the film. In order to alleviate the red-eye phenomenon, there are many optical devices capable of “red-eye alleviation illumination” that irradiates a subject with light immediately before exposure.

  There are two types of illumination means capable of red-eye reduction illumination. One is a strobe pre-irradiation type that emits a strobe once before exposure, and the other is a red-eye mitigation lamp type that is individually provided with illumination means such as a lamp and LED.

  The strobe pre-irradiation type uses both red-eye mitigation illumination and a strobe light emitting member, so that there is an advantage that an additional member or the like is unnecessary and a space is not required. However, it is necessary to devise a circuit such as separating the pre-light-emitting capacitor and the main light-emitting capacitor or making a circuit configuration capable of intermittent light emission. In addition, when pre-irradiated, there is a problem that the person who is the subject moves at the exposure timing mistakenly with the main light emission, or the strobe at the time of pre-irradiation is dazzling.

  On the other hand, the red-eye mitigating lamp type requires different light emitting members, requires a control circuit, etc., and the irradiation luminance is weaker than the strobe pre-light emission type, requiring a pre-irradiation time of about 1 second before exposure. There are problems such as. However, since the problem of the strobe pre-irradiation type can be avoided, the red-eye mitigation lamp type has been widely adopted recently.

  Further, in recent cameras, an automatic focus adjustment function, so-called autofocus (AF) function is indispensable. There are two types of AF functions. One is an active method that irradiates the subject with infrared rays, etc., receives the reflected light and measures the distance to the subject, and the other detects the subject image with the left and right sensors, and the image displacement. This is a passive method that measures the distance to the subject by an amount (phase difference).

  Since the active method projects infrared light or the like, it is effective for distance measurement of a dark subject or the like. However, there is a limit to the light projection capability, and it is difficult to perform accurate distance measurement on a far-side subject.

  On the other hand, the passive method has an advantage that it can accurately measure a distance even with an infinite subject because it detects an image. However, it is not suitable for ranging in the dark where it is difficult to recognize images. Therefore, many cameras using passive distance measuring means include so-called auxiliary light that detects an image by irradiating light from the camera in order to be applied to distance measurement in the dark. Auxiliary light that is commonly used as the above-described red-eye mitigation irradiation means is becoming common.

  For example, Patent Document 1 discloses a technique in which the same light source is used as auxiliary light for red-eye reduction and focus detection, and the luminance of the light source is changed according to the purpose.

  Patent Documents 2 and 3 disclose a technique that combines the red-eye mitigation illumination unit and the focus detection auxiliary light.

  Further, a technique is disclosed in which the same light source is used as the red-eye mitigating means driven by a constant current and auxiliary light, and the current of the light source is changed in order to obtain appropriate light distribution and luminance according to the purpose of use.

  In addition to the above, the red-eye mitigation irradiation means, particularly the red-eye mitigation lamp, has been increasingly used as a display for mode warning / countdown warning for a self-timer or a remote controller.

  When the irradiation means capable of red-eye mitigation illumination is used for other purposes (for example, AF auxiliary light), the number of times of lighting increases. For this reason, it is necessary to use an irradiation means having higher lighting durability than conventional. In a lamp used for a camera such as a compact camera that requires space saving, it is very difficult to reduce the size, obtain a predetermined brightness, and improve the durability.

On the other hand, Patent Document 4 discloses a technique for driving a lamp with a constant current. In the case of performing constant current driving, since an inrush current to the lamp can be prevented, there is a considerable merit in terms of stability of brightness and improvement of lamp durability.
JP 7-333694 A JP-A-1-293331 JP-A-9-005843 JP-A-5-150302

  However, the constant current driving of the lamp generally has a drawback that the rise is delayed by the amount of no inrush current. Therefore, the time from the start of lighting until the luminance is stabilized is longer than that in general voltage driving.

  The rise of the lamp illuminates in units of several seconds like a self-timer warning and has little effect on those that do not require a sharp brightness change, but those that require a sharp brightness change such as a red-eye reduction function or AF auxiliary light It becomes a problem for a short measurement period. If the luminance change of red-eye relaxation is slow, the pupil of the subject cannot be sufficiently narrowed, and red eyes are generated, or if AF is performed immediately after the lamp is lit, the luminance is insufficient and sufficient auxiliary light effect is obtained. It may not be obtained. If a waiting time is provided until the brightness of the lamp is stabilized, the waiting time becomes a time lag, and the comfort of operation is impaired.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to improve the convenience of a camera by driving a lamp by an appropriate driving method according to the use of the lamp.

  The present invention relates to a camera, comprising: an illumination unit including a lamp; and a control circuit that switches between a first mode in which the lamp is driven with a first driving capability and a second mode in which the lamp is driven with a second driving capability. It is characterized by providing.

  According to the present invention, the convenience of the camera can be improved.

[First embodiment]
A preferred first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a circuit block diagram of main parts of a camera according to a preferred first embodiment of the present invention.

  A power supply battery 1 (for example, a 3V lithium battery) of the camera is connected to a control circuit 2 such as a microcomputer that controls various operations of the camera. The control circuit 2 includes an A / D converter 2-1, a D / A converter 2-2, a storage unit (memory) 2-3, and the like. The control circuit 2 includes a main switch 3 for switching the operation / non-operation state of the camera, a release switch 4 for starting a photographing operation, a known photometry unit (AE) 5 for detecting subject luminance, and a self-timer. It is connected to a mode switch 12 for setting a mode and a remote control (hereinafter referred to as “remote control”) mode.

  The control circuit 2 also controls the illumination unit 6 for alleviating the red-eye phenomenon that occurs mainly during strobe light emission. The illumination unit 6 includes a red-eye lamp driving unit 6-1 and a red-eye lamp 6-2. In the present embodiment, the red-eye lamp driving unit 6-1 includes a constant current circuit for supplying a constant current to the red-eye lamp 6-2. The set current of the red-eye lamp driving unit 6-1 can be set by the control circuit 2. The control circuit 6 can switch between a first mode in which a lamp such as a red-eye lamp is driven with the first driving ability and a second mode in which the lamp is driven with the second driving ability. The time until the voltage or current applied to the lamp in the first mode reaches a predetermined voltage or current is longer than the time until the voltage or current applied to the lamp reaches the predetermined voltage or current in the second mode. It is desirable that the length of the

  The control circuit 2 also controls a known distance measuring unit (AF) 7 that detects the distance to the subject. In the present embodiment, the distance measuring unit 7 uses a passive distance measuring unit. When it is difficult to detect an image of a subject due to low environmental brightness during distance measurement, the illumination unit 6 irradiates the subject. That is, the illumination unit 6 can be used (also used) as auxiliary light for the distance measuring unit 7.

  The control circuit 2 also applies the lens driving unit 8 for adjusting the focus of a photographing optical system (not shown) according to the distance measurement result of the distance measuring unit 7 and the film luminance information of the subject obtained by the photometry unit 5. A light emitting unit for irradiating strobe light when exposing the film when the brightness information of the subject obtained by the shutter control unit (SH) 9 and the photometry unit 5 for performing proper exposure is darker than a predetermined luminance. A strobe control unit 10 including a voltage charging unit and the like, a feeding unit 11 for winding and rewinding a film, and a remote control receiving unit 13 for receiving a remote control signal are controlled.

  FIG. 2 is a flowchart showing the operation when the camera is ready for operation by the main switch 3.

  In step S1, the control circuit 2 detects whether or not the release switch 4 is turned on. If it is turned on, the control circuit 2 proceeds to step S2, and if not, the process proceeds to step S3.

  In step S2, the control circuit 2 shifts to a sequence of photographing operations described later.

  In step S3, the control circuit 2 detects whether or not the mode switch 12 is turned on and the self-timer / remote control mode is set. If it is turned on, the control circuit 2 proceeds to step S4, and if not, proceeds to step S5. .

  In step S4, the control circuit 2 shifts to a sequence of a self-timer / remote control mode described later.

  In step S5, the control circuit 2 detects whether or not the main switch 3 is turned off. If it is turned off, the control circuit 2 returns to step S6, and if it is not turned off, the process returns to step S1.

  In step S6, the control circuit 2 executes a sequence in which the camera is inactivated, and returns to the camera operation standby state. Such a sequence includes, for example, an operation for storing the lens barrel including the photographing optical system in the camera body, an operation for canceling the mode setting, and the like.

  The above is the operation sequence when the camera according to the preferred embodiment of the present invention is operable.

  FIG. 3 is a flowchart showing a detailed operation of the photographing operation sequence shown in step S2 of FIG.

  In step S11, the control circuit 2 controls the photometry unit 5 so as to perform well-known subject luminance measurement (photometry).

  In step S12, the control circuit 2 controls the distance measuring unit 7 so as to perform a well-known subject distance measurement (range measurement). In step S12, the control circuit 2 determines whether or not the auxiliary light from the illumination unit 6 is used based on the photometric result obtained in step S11 (refer to FIG. 4 for the detailed sequence of this determination). To explain.)

  In step S13, the control circuit 2 determines the focus adjustment amount of the optical system (not shown), the exposure amount of the film, the presence / absence of strobe light emission, and the like based on the photometry results and the distance measurement results acquired in steps S11 and S12. For the operation.

  In step S14, the control circuit 2 determines whether or not strobe light is emitted during the film exposure operation based on the calculation result in step S13. If strobe light is emitted, the process proceeds to step S15. Shifts to step S16 (the operation of this step is well known, and detailed description thereof is omitted in this embodiment).

  In step S15, the control circuit 2 controls to perform a well-known exposure operation (strobe photographing operation) on the film by a strobe emission method. In step S15, the control circuit 2 is configured to control the illumination unit 6 so as to illuminate the subject before the start of exposure (before strobe light emission) (details of this method will be described with reference to FIG. 5). .)

  In step S16, the control circuit 2 performs control so as to perform a well-known exposure operation on the film by a method that does not perform strobe light emission.

  In step S17, the control circuit 2 controls the feeding unit 11 so as to wind up the exposed film by one frame and set the next frame, and the photographing operation sequence is completed.

  The above is the detailed operation of the shooting operation sequence according to the preferred camera of the present invention.

  FIG. 4 is a flowchart showing the distance measuring operation in step S12 of FIG.

  In step S <b> 21, the control circuit 2 drives the distance measurement unit 7 and performs control so as to perform distance measurement signal observation (image detection) of a known passive (object image phase difference detection) method.

  In step S22, the control circuit 2 determines whether or not the contrast or luminance of the image signal detected by the distance measuring unit 7 in step S21 is equal to or greater than a predetermined value. If it is equal to or greater than the predetermined value, the control circuit 2 proceeds to step S28. If it is less (assuming that the subject has low contrast or low brightness), the process proceeds to step S23.

  In step S23, the control circuit 2 determines whether or not the brightness of photometry is equal to or less than a predetermined value based on the photometry result AE detected by the photometry unit 5 in step S11 of FIG. If it is more than a predetermined value to step S24, it will transfer to step S29.

  In step S24, the control circuit 2 controls the illuminating unit 6 so that the illuminating unit 6 is lit in the “second mode” as auxiliary light for focus detection. The “second mode” is a mode in which the set current of the red-eye lamp driving unit 6-1 is driven at or above the rating of the red-eye lamp 6-2. For example, when a lamp with a rating of 2.0 V and 250 mA is used, the set current is set to 500 mA. In this case, in reality, the current that can be flowed when the rated voltage of the lamp of 2.0 V is applied is a rating of 250 mA. Therefore, the voltage required for setting the constant current of the red-eye lamp driving unit 6-1 is 0.5 V. In this case, even when the power supply battery 1 is 3V, the voltage applied to the red-eye lamp 6-2 is 2.5V, and the difference between the rated voltage 2.0V of the red-eye lamp 6-2 and the actual applied voltage 2.5V. Therefore, the actually set current of 500 mA is not always applied to the red-eye lamp 6-2. That is, the red-eye lamp 6-2 is pseudo-voltage driven.

  With such a setting, in the “second mode”, as shown in FIG. 10B, a large inrush current flows through the red-eye lamp 6-2 of the illumination unit 6 until the red-eye lamp 6-2 reaches a desired luminance. The rise time becomes extremely short.

  The set value of the constant current described above is shown as an example, and the present invention is not limited to this. As the set value of the constant current, for example, the inrush current (for example, 350 mA) may be ensured so that the rise time until the predetermined brightness of the red-eye lamp 6-2 becomes shorter than the predetermined time t (for example, 100 msec).

  In step S25, similarly to step S21, the control circuit 2 drives the distance measurement unit 7 and performs control so as to perform distance measurement signal observation (image detection) of the known passive (subject image phase difference detection) method.

  In step S26, the control circuit 2 performs control so that the illumination unit 6 that is lit in step S24 is turned off.

  In step S27, as in step S22, the control circuit 2 determines whether the contrast or brightness of the image signal detected by the distance measuring unit in step S25 is greater than or equal to a predetermined value. If it is less than the predetermined value, the process proceeds to step S29.

  In step S28, the control circuit 2 performs distance measurement for measuring the distance of the subject from the image signal of the subject detected in step S21 or step S25, and stores the distance measurement result in a memory (not shown) of the control circuit 2. After that, the ranging operation sequence is completed.

  In step S29, the control circuit 2 determines that the contrast or brightness of the image signal greater than or equal to the predetermined value could not be detected in step S21 or step S25, and outputs a distance measurement result (for example, outputs a warning display and infinite distance measurement result). The processing result is stored in a memory (not shown) of the control circuit 2 and the ranging operation sequence is terminated.

  The above is the detailed sequence of the distance measuring operation according to the preferred first embodiment of the present invention.

  Note that the time between step S24 to step S26 in FIG. 4, that is, the time during which the illumination unit 6 is lit in the second mode is, for example, about several hundreds msec (for example, 500 msec).

  FIG. 5 is a flowchart showing the flash photographing operation in step S15 of FIG.

  In step S31, the control circuit 2 detects whether or not the voltage required for the strobe control unit 10 to emit light is sufficiently charged. If not, the control circuit 2 proceeds to step S32. If it is charged, the process proceeds to step S32. To do.

  In step S32, the control circuit 2 operates the voltage charging function of the strobe control unit 10 to perform a known charging operation, and proceeds to step S33 when a predetermined voltage can be charged.

  In step S <b> 33, the control circuit 2 controls the illumination unit 6 so as to be lit in the “second mode”.

  In step S34, the control circuit 2 starts the operation of a built-in timer (not shown).

  In step S35, the control circuit 2 determines whether or not the timer operated in step S34 has elapsed a predetermined time (for example, 1.25 sec), and proceeds to step S36 when the predetermined time has elapsed.

  In step S36, the control circuit 2 controls to turn off the illumination unit 6 that was turned on in step S33. That is, the irradiation for “red-eye reduction” is performed for a predetermined time (for example, 1.25 sec) in steps S33 to S36.

  In step S37, the control circuit 2 drives and controls the lens driving unit 8 so as to perform a so-called focus adjustment operation in which the photographing optical system is moved by the focus adjustment amount determined in step S13 in FIG.

  In step S38, the control circuit 2 performs a so-called strobe exposure operation in which the photographing optical system performs appropriate exposure (strobe photographing) on the film determined in step S13 of FIG. 10 is driven and controlled.

  In step S39, the control circuit 2 drives and controls the lens driving unit 8 so as to perform a so-called lens reset operation for moving the photographing optical system to the standby position, and ends the sequence of the strobe photographing operation.

  The above is the detailed sequence of the strobe shooting operation according to the preferred first embodiment of the present invention. In the preferred embodiment of the present invention, the strobe shooting operation is described as a state in which the red-eye reduction function is always activated. However, the present invention is not limited to this, and the red-eye reduction is performed in some of the plurality of strobe shooting modes. A function may be activated.

  FIG. 6 is a flowchart showing the self-timer / remote control mode operation described in step S4 of FIG.

  In step S41, the control circuit 2 detects whether or not the voltage for the strobe controller 10 to emit light is sufficiently charged. If not, the control circuit 2 proceeds to step S42, and if charged, the process proceeds to step S43. To do.

  In step S42, the control circuit 2 operates the voltage charging function of the strobe control unit 10 to perform a known charging operation, and proceeds to step S43 when a predetermined voltage has been charged.

  In step S43, the control circuit 2 determines whether or not the remote control receiving unit 13 has received a shooting command signal from a remote control transmitter (not shown). If received, the control circuit 2 proceeds to step S50. Control goes to step S44.

  In step S44, the control circuit 2 determines whether or not the release switch 4 is turned on in the self-timer / remote control mode. If not, the control circuit 2 proceeds to step S45. If it is turned on, the self-timer is activated. Control goes to step S46.

  In step S45, the control circuit 2 detects whether the mode switch 12 is turned off and the self-timer / remote control mode is released. If it is not turned off, the process proceeds to step S43. finish.

  In step S46, the control circuit 2 sets a counter X (not shown) therein to a predetermined value (for example, X = “8”).

  In step S47, the control circuit 2 controls the illumination unit 6 so as to perform warning lighting of the self-timer. The warning lighting in step S47 is performed in the “first mode” as in step S33 in FIG. 5 (step S47 will be described in detail with reference to FIG. 7).

  In step S48, the control circuit 2 subtracts 1 count (X = X-1) from a counter X (not shown) therein.

  In step S49, the control circuit 2 determines whether or not the counter value set in step S48 has become “0”, that is, whether or not the so-called countdown has ended. If completed, the process proceeds to step S50.

  In step S50, the control circuit 2 controls the illumination unit 6 to perform lighting for a predetermined time (for example, lighting for 2 seconds) as part of the warning lighting of the remote controller or the warning lighting of the self-timer. The warning lighting in step S50 is performed in the “first mode” similarly to steps S33 to S36 in FIG. Since this step S50 includes a substantially similar sequence except that the operation of steps S33 to S36 in FIG. 5 is different from the timer setting time, detailed description thereof will be omitted.

  In step S51, the control circuit 2 executes the above-described photographing operation of FIG. 3 and ends the self-timer / remote control mode operation.

  FIG. 7 is a flowchart showing the warning lighting operation of the self-timer in step S47 of FIG.

  In step S61, the control circuit 2 sets a built-in timer (not shown) to a predetermined time T1 (for example, 500 msec) and starts operation.

  In step S62, the control circuit 2 controls the illumination unit 6 so as to be lit in the “first mode”. The “first mode” is a mode in which the set current of the red-eye lamp driving unit 6-1 is driven within the rating of the red-eye lamp 6-2. For example, when a lamp with a rating of 2.0 V and 250 mA is used, a constant current drive of 250 mA is performed.

  With this setting, in the “first mode”, as shown in FIG. 10A, the inrush current to the red-eye lamp 6-2 of the illumination unit 6 is eliminated, and an instantaneous overcurrent is applied to the red-eye lamp 6-2. As a result, the durability can be improved. In addition, the “first mode” has a longer rise time until reaching the desired luminance than the “second mode” (for example, 100 msec longer than the predetermined time t). Therefore, in the “first mode”, for example, if the predetermined time t is 100 msec, the desired luminance is reached after 200 msec.

  In step S63, the control circuit 2 determines whether or not the timer operated in step S61 has elapsed a predetermined time T1 (for example, 500 msec). When the predetermined time has elapsed, the control circuit 2 proceeds to step S64.

  In step S64, the control circuit 2 sets a built-in timer (not shown) to a predetermined time T2 (for example, 500 msec) and starts operation.

  In step S65, the control circuit 2 performs control so that the illumination unit 6 is turned off.

  In step S66, the control circuit 2 determines whether or not the timer operated in step S64 has elapsed a predetermined time T2 (for example, 500 msec). When the predetermined time has elapsed, the sequence of the self-timer warning lighting operation is terminated. That is, in this sequence, the illumination unit 6 is blinked by turning on / off at predetermined times T1 and T2, and is used as a reference for the warning for the self-timer. The predetermined times T1 and T2 are set to substantially the same time in this embodiment, but are not limited to this. For example, considering that the rise time at the start of lighting is slow, T1 = 750 msec, It may be set as T2 = 250 msec. Further, although the sequence using blinking has been described as the warning lighting of the self-timer, the present invention is not limited to this, and the warning lighting may be performed only by lighting, for example.

  The above is the detailed sequence of the warning lighting operation for the self-timer in step S47 of FIG.

  As shown in FIGS. 6 and 7, according to the warning lighting of the self-timer / remote controller of the present invention, by controlling the lighting unit 6 in the “first mode”, the inrush current to the lighting unit 6 is suppressed, Durability can be improved.

[Second Embodiment]
In the first embodiment described above, the illumination unit is driven with a constant current. However, in a preferred second embodiment of the present invention, an example of a lighting method when the illumination unit is driven with a voltage is shown. Since the basic sequence and the like are roughly the same as those in the first embodiment, the description thereof is omitted.

  FIG. 8 is a diagram showing a circuit configuration of the illumination unit 6 ′ according to the preferred second embodiment of the present invention.

  The control red-eye lamp driving unit 6-1 includes first and second current paths for flowing current to the red-eye lamp 6-2. The red-eye lamp driving unit 6-1 further includes a switching element Tr1 for “first mode” control, a “first mode” current limiting resistor R1 disposed in the first current path, and “second mode” control. Switching element Tr2 and “second mode” current limiting resistor R2 disposed in the second current path. The control circuit 6 allows a current to flow through the first current path in the first mode, and allows a current to flow through the second current path in the second mode. The control red-eye lamp driver 6-1 is connected to the red-eye lamp 6-2.

  The current limiting resistors R1 and R2 are configured so that their resistance values satisfy the relationship of R1> R2. The limiting current by R1 is set to be less than the rating of the red-eye lamp 6-2, and the limiting current by R2 is set to be not less than the rating of the red-eye lamp 6-2. In the present embodiment, the switching elements Tr1 and Tr2 have substantially the same characteristics, but the present invention is not limited to this.

  When the “first mode” is selected, the red-eye lamp driving unit 6-1 turns on the switching element Tr1 and turns off the switching element Tr2, and the red-eye lamp 6-2 is driven by the limiting current of the resistor R1. It becomes a state.

  On the other hand, when the “second mode” is selected, the red-eye lamp driving unit 6-1 turns off the switching element Tr1 and turns on the switching element Tr2, and drives the red-eye lamp 6-2 with the limiting current of the resistor R2. It will be in a state to be. For example, when the red-eye lamp 6-2 has a rating of 2.0 V and 250 mA, the limiting current by R1 is set to 230 mA, and the limiting current by R2 is 1 A, the rising waveform of the red-eye lamp 6-2 is as shown in FIG. 11 as shown.

  In FIG. 11A, since the current is limited by the resistor R1, inrush current does not flow, and durability is improved. However, since the predetermined voltage cannot be reached by the predetermined time t, the predetermined luminance cannot be reached by the predetermined time t.

  In FIG. 11B, the current is limited by the resistor R2, but since it is limited to the rated current or more, an inrush current flows. As a result, the predetermined voltage can be reached by the predetermined time t, and the predetermined luminance can be reached sooner.

  As described above, even when the voltage of the illumination unit is controlled, the “first mode” and the “second mode” can be switched according to the usage by changing the inrush current using the limiting resistor.

  In the present embodiment, each switching element is provided in order to switch the limiting resistance. However, the present invention is not limited to this, and for example, a resistor is provided in series with the red-eye lamp 6-2. A switching element that short-circuits both ends of the resistor may be arranged, and a method of changing the current limiting state by the switching element or a method of changing the limiting current by the base resistance of the switching element (transistor) may be employed.

[Third embodiment]
The third preferred embodiment of the present invention shows an example of a lighting method when the illumination unit is voltage-driven as in the second embodiment described above. The illuminating unit according to the third preferred embodiment of the present invention changes the inrush current by a method of energizing the red-eye lamp 6-2 while being voltage driven.

  FIG. 9 is a diagram showing a circuit configuration of the illumination unit 6 ″ according to the preferred third embodiment of the present invention. This embodiment has a configuration similar to that of the “second mode” control circuit (Tr2 and R2) described in the second preferred embodiment of the present invention. That is, normally, the red-eye lamp 6-2 can be lit in the “second mode” by turning on the switching element Tr2 in a DC manner. FIG.11 (b) is a figure which shows the electricity supply waveform in this case.

  The third preferred embodiment of the present invention is a method of reaching a predetermined luminance without causing an inrush current to flow through the red-eye lamp 6-2 by performing pulse energization as a “first mode” on the circuit of FIG. It is.

  FIG. 12 is a diagram illustrating a control waveform of the switching element Tr2 of FIG. 9 and a waveform of the voltage applied to the red-eye lamp 6-2 (= luminance increase waveform). A voltage pulse train is supplied to the switching element Tr2 for a predetermined time from the start of driving of the red-eye lamp 6-2. At the time of startup, since the switching element Tr2 is turned on / off at an interval shorter than the rise time of the inrush current, the inrush current does not flow. Since the inrush current does not flow, the red-eye lamp 6-2 is gradually warmed, and the ON time can be gradually increased to reach a predetermined luminance.

  The above is the preferred third embodiment of the present invention.

  In the above-described preferred embodiment of the present invention, the camera using the silver film is exemplarily shown. However, the present invention is not limited to this, and the same effect can be obtained in, for example, a digital camera.

  As described above, the camera according to a preferred embodiment of the present invention includes the first mode in which the degree of request for speed without any problem is small as long as the rising time at the time of the illumination unit is within a predetermined time, and the illumination unit And a second mode in which a quick rise time is required. Therefore, according to a preferred embodiment of the present invention, when the lighting unit is turned on in the first mode, the setting within the rated current or the setting that is difficult to apply the inrush voltage is performed, and when the lighting unit is turned on in the second mode. The convenience of the camera can be improved by applying an inrush current to accelerate the rise of lighting.

It is a circuit block diagram of the principal part of the camera which concerns on suitable 1st Embodiment of this invention. It is a flowchart which shows the operation | movement in the camera operable state which concerns on suitable 1st Embodiment of this invention. 3 is a flowchart showing a photographing operation according to the preferred first embodiment of the present invention. It is a flowchart which shows the ranging operation which concerns on the suitable 1st Embodiment of this invention. 3 is a flowchart showing a strobe photographing operation according to the preferred first embodiment of the present invention. 5 is a flowchart showing a self-timer / remote control mode operation according to the preferred first embodiment of the present invention. It is a flowchart which shows the warning lighting operation | movement for self timers concerning the suitable 1st Embodiment of this invention. It is a figure which shows the circuit structure of the illumination part which concerns on suitable 2nd Embodiment of this invention. It is a figure which shows the circuit structure of the illumination part which concerns on the suitable 3rd Embodiment of this invention. It is a figure which shows the lighting current waveform to the illumination part which concerns on suitable 1st Embodiment of this invention. It is a figure which shows the lighting current waveform to the illumination part which concerns on suitable 2nd Embodiment of this invention. It is a figure which shows the lighting current waveform to the illumination part which concerns on suitable 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Power supply battery, 2 ... Control circuit, 2-1 ... A / D converter, 2-2 ... D / A converter, 2-3 ... Memory | storage part (memory), 3. ..Main switch, 4 ... release switch, 5 ... photometry unit, 6 ... illumination unit, 6-1 ... red eye lamp drive unit, 6-2 ... red eye lamp, 7 ... Distance measuring unit (passive method), 8 ... lens driving unit, 9 ... shutter control unit, 10 ... strobe control unit, 11 ... feeding unit, 12 ... mode switch, 13 ... Remote control receiver, Tr1, Tr2 ... switching elements, R1, R2 ... limiting resistors

Claims (12)

An illumination unit comprising a lamp;
A control circuit that switches between a first mode in which the lamp is driven with a first driving capability and a second mode in which the lamp is driven with a second driving capability;
A camera comprising:   2. The camera according to claim 1, wherein a time until the lamp reaches a predetermined luminance in the first mode is longer than a time until the lamp reaches the predetermined luminance in the second mode.   The camera according to claim 1, wherein the illumination unit includes a constant current circuit for supplying a constant current to the lamp.   The value of the constant current is set so that an inrush current flowing through the lamp in the first mode is smaller than an inrush current flowing through the lamp in the second mode. camera.   The camera according to claim 3, wherein the constant current is set to be equal to or less than a rated current value of the lamp in the first mode.   The camera according to claim 3, wherein the constant current is set to be equal to or higher than a rated current value of the lamp in the second mode. The illumination unit includes first and second current paths for flowing current to the lamp,
The first current path has a first resistance;
The second current path has a second resistance;
7. The control circuit according to claim 1, wherein a current flows through the first current path in the first mode, and a current flows through the second current path in the second mode. The camera according to item.   4. The camera according to claim 3, wherein the constant current circuit supplies a pulse train of voltage to the illumination unit for a predetermined time from the start of driving of the lamp in the first mode.   The camera according to any one of claims 1 to 8, wherein the illumination unit performs the red-eye alleviation illumination using the lamp in the second mode.   The camera according to any one of claims 1 to 8, wherein the illumination unit performs lighting for assisting focus detection using the lamp in the second mode.   9. The camera according to claim 1, wherein in the first mode, the illumination unit performs a warning light of a self-timer by using the lamp.   9. The camera according to claim 1, wherein the illumination unit performs remote control warning lighting using the lamp in the first mode. 10.

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