GB2270391A - Strobe control apparatus for a camera - Google Patents

Abstract

The invention provides a control apparatus for a camera with incorporated strobe device (12) movable into an operative position and provided with a control unit (20) for the determination of exposure parameters on the basis of object brightness determined by a light measuring apparatus wherein the control unit (20) under selected circumstances drives the strobe device (12) via a drive apparatus into its operative position; wherein a detection apparatus (SW4) is provided to detect whether or not the strobe device is in the operative position, and wherein the control unit (20) adjusts the exposure parameters determined without taking into consideration the incorporated strobe device, when the detection apparatus (SW4) does not detect the strobe device (12) in its operative position. <IMAGE>

Description

2270391 STROBE CONTROL APPARATUS FOR A CAMERA pi.esent. iiiv(iit-j(jii

relates lo a strobe coritrol for a camera having a strobe incorporated therein, and moie 1)ie(,-.jsely it: relat-es to a corilrol apparalus for preventing a faulty operation in a camera.

T 11 e 1111111bel- f- havilAq a u 1 oma 1. j c 119111 1110d tl lit t j (311 t Ype S t. 1 o bes has been recently i.ticreasi.iig, because of easy handl inj there0E. A strobe eonta1ning cameia has a sliobe control apparatus is also known, in which a lighl emit-Ler of the st-robe is supported by a S u p po r t_ iitecliaiiisin, sitch as a retractable inechanism or a pop-up ittecliazii.sni so as Lo move between a retracted position .o In wilicl, the light emitter is retracted into the camera body and EAji operative position, i.e., a light eittitting Position in Che _light exitilter projects outward from the camera body by an e_lectrical. actuator (e.g., an electrically driven illotor) lit such a known sIrobe eonli-ol apparatus, the cozit-.i.-(.)] of strobe light emi.ssion i.s usual.ly effected in accordallee with expo.sure faclors, such as brightness data of an objecl to be taken or calculated shutter speed data. Namely, when the object brightness is below a predetermined value upon 3 0 photographing, the light entitter is brought to the operative position to emit. strobe ii.glit. Afler L-lie strobe light: is emitted, the light emitter is returned to Lhe posi.tioll. Converse 1 y, if the ob-ect 1)i-i.clilii(3ss j 9 is above a predetermined value, the light emi.tter is retained :15 in the retracted posi.tion, since no strobe li.glit is necessary.

However, in the conventional Gaille-ra having a strobe 2- control apparatus as mentioned above, there is a possibility that the light enlitter does not move to the operative position for some reason. For instance, the light entitter can riot move, if the light emitter is held 13y a photographer's hand, or- if a detachable external strobe of a special shape is attached to the camera so that the detachable external strobe- interferes with the light emitter, etc. It goes without saying that no clear picture call be taken even if sliobe light is emitted from the light emitter which has not nioved to the operative position.

llowever, conventional cameras have not focused on the solution to the problems mentioned above. Therefore, for example, if the light emitter which is not in the operative position emits strobe light-, an under-exposure 1 5 occurs or a uniform brightness distribution cannot be obtained. Conversely, if shutter" release is prohibited when the light emitter is not moved to the operative position, a photographer may miss taking a photog-raph.

Further, it is also known to provide a compulsive light emitting switch which is actuated to change the photographing mode to a compulsive light emitting mode in which strobe light can be compulsively emitted regardless of the brightness of an object to be taken. However, the provision of such an additional compulsive light emitting switch makes the camera more complicated.

Furthermore, a strobe- incorporated AF camera is known having an auxiliary light emitter which emits a contrast pattern when the object brightness is below a predetermined value, or a camera having a self-timer photographing function. In these known cameras, tile auxiliary light emitter is provided in the main strobe light emitter or in the camera body, and a self timer indicator for indicating the self timer operation is provided in the camera body.

However, the location of the self timer indicator in the camera body is restricted, especially if the camera -3body is housed in a body case. There is also a possibility that the photographic lens may interfere with the self timer indicator, so that it may be difficult for a photographer to observe the indicator, depending on the position of an object to be taken, even in a photographic range in which a picture of the object can be taken- In a strobe-incorporating camera, the strobe light emitter can be observed at any place within an area which can be illuminated with the strobe light when the strobe light is emitted. Accordingly, in theory, it is possible to provide the self tinier indicator in the strobe- light emitter.

However, in this possibility, the self tillier indicator can not be observed from the-side of the object.

when the strobe light emitter is in the retracted positioii (inoperative position) in which it is retracted in thecamera body.

Therefore, to make it possible to observe the self timer indicator, the strobe light emitter must be moved to the operative position in which the light emitter projects outward from the camera body even in the self timer mode in which no strobe light is required. This is however not practicable particularly in a camera in which the light emitter is manually disengaged from a locking member to move it to the operative position, since if a photographer fails to disengage the light emitter, no indication of the self timer indicator can be observed, so that no release timing can be learned.

The primary object of the present invention is to eliminate the above mentioned drawbacks of the conventional strobe- incorporated camera having a strobe light emitter movable between a retracted position (inoperative position) 35and an operative position (light emitting position), by providing a s t robe- incorporated camera which can be easily 4 handled, effectively fulfils the strobe function and can reduce the possibility ineffective photography.

According to the present invention therefore there is provided a control apparatus for a camera with incorporated strobe device movable into an operative position and provided with a control unit for the determination of exposure parameters on the basis object brightness determined by a light measuring apparatus wherein the control unit under selected circumst-ances drives the strobe device via a drive apparatus into its operative position; wherein a detection apparatus is provided to detect whether or not the strobe device is in the operative position, and wherein the control unit adjusts exposure parameters determined without taking into consideration the incorporated strobe device, when the detection apparatus does not detect the strobe device in its operative position.

The control unit may prevent light emission by the incorporated strobe device when the detection apparatus does not detect the strobe device in its operative position.

In such arrangements in addition an external strobe device may be provided on the camera wherein the control unit prevents light emission by the internal strobe device and causes the external strobe device to emit light, when the detection apparatus does not detect the strobe device in its operative position.

The control unit may control the strobe device in its operative position when the detected object brightness is below a predetermined value.

6 In the arrangement of the invention an exposure parameter determined by the control unit on the basis of the object brightness determined by the light measurement unit may contain a shutter speed, the arrangement may be such that the control unit moves the strobe device to its operative position when the determined shutter speed lies below a predetermined value.

In another aspect of the invention the control unit may cause the light emitting element to move to the retracted position af ter the incorporated strobe device has emitted light.

The compulsive light emitting switch unit may be arranged to activate a compulsive light emitting mode in which a strobe flash is compulsively emitted. The control unit may then by adapted to move the strobe device via the drive means into the operative position when the compulsory light emitting mode is activated.

In another aspect of the invention the control unit may prevent the incorporated strobe from emitting light when the detecting means does not detect that the strobe device is in the operative mode.

The invention will be described below by way of illustration only, in detail with reference to the accompanying drawings, in which:

Figure 1 is a schematic view of a strobe light emitter and the surroundings thereof in an automatic focusing singlelens reflex camera having a strobe incorporated therein, to which the present invention is applied; Fig. 2 is a front elevational view of a camera shown in Fig- 1, with an external strobe attached thereto, shown in an operative position in which a light emitter of an incorporated strobe projects outward from the camera body; Fig. 3 is a block diagram schematically showing a circuit arrangement of a single-lens reflex camera shown in Fig. 1; Figs. 4A, 4B, 4C and 5 are flow charts of the operations of a singlelens reflex camera shown in Fig. 1; Figs. 6A, 6B and 6C are flow charts of the operations of a single-lens reflex camera, according to another embodiment of the present invention; Figs. 7 through 9 are views similar to Figs. 1 through 3, according to a third embodiment of the present invention which is applied to a strobe- incorporated camera having a self timer photographing function; Figs. 10A and lOB are flow charts of the operations of a single-lens reflex camera according to a third embodiment of the invention, shown in Figs. 7 through 9; -B- Fig. 11 is a view similar to Fig. 1, showing another embodiment of a self timer indicator; Fig. 12 is a schematic view of a modified embodiment showing an optical system having a condenser lens and a diffusing optical element; Fig. 13 is a perspective view of a strobe light emitter and the surroundings thereof, according to a fourth embodiment of the present invention; Figs. 14A and 14B are sectional views of a strobe 1 i gilt exiii tter shown i 11 a retracted position and an opei,ative position, according to a third embodiment-of the invention, respectively; -Fig. 15 is a view similar to Fig. 1, according to a fourth embodiment of the present invention; and, is Figs. 16A through 16D are flow charts of the operations of a single-lens reflex camera according to a fourth embodiment of the present invention.

The following discussion will be directed to preferred-embodiments of the present invention.

Figure 1 schematically shows a powered retractable type of strobe to which the present invention is applied.

Fig. 2 shows a single-lens reflex camera which includes a strobe control apparatus according to the present invention. In Fig. 2, the light emitter of the strobe is in the operative position (light emitting position) in which the light emitter projects outward from the camera body. A detachable external strobe 25 which will be described hereinafter is attached to the camera body in Fig. 2.

In Figs. 1 and 2, a camera body 10 is provided, on its upper portion (pentagonal prism 11), with a strobe light emitter 12 which is supported by a supporting mechanism so as to move between a retracted position shown at an imaginary line in which the light emitter 12 is -9retracted in a receiving portion 10a of the camera body 10 and an operative position (light emitting position) shown at a solid line in which the light emitter 12 protrudes from the receiving portion 10a. Note that only one of levers 13 which constitute the supporting mechanism is shown in Fig. 1.

Each of the levers 13 is pivotted at its one end to the rear end of the light emitter 12 through a shaft 13a and at its opposite end to the side wall of the receivi.ii(l portion 10a provided in the camera body 10 through a shaft 13b. One of the levers 13 has a sector gear 14 having a center located on the center axis of the shaft 13b. The sector gear 14 is indirectly in mesh with a pinion 17 of a strobe motor 16 which constitutes a driving means through a gear train 15. Consequently, the rotation of the strobe molot 16 is transmitted to the levers 13 through the gears 17, 15 and 14, so that the strobe light emitter 12 is moved between the retracted position and the operative positiou through the levers 13, in accordance with the direction of the rotation of the motor 16.

Two limit switches 18 and 19 are provided between the levers 13 and the camera body 10 to detect the retracted and operative positions of the light emitter 12. Namely, the switches 18 and 19 are switched ON, when the light emitter comes to the retracted position and the operative position, respectively.

The operation of the strobe motor 16 is controlled by the camera control circuit 20, so that the strobe motor 16 is stopped in accordance with the detection of the switches 18 and 19. The detectors for detecting the retracted position and the operative position of the lighl emitter are not limited to the limit switches 18 and 19, as illustrated in the drawings, and can be composed of for example a combination of a brush and a code plate having coded contacts which selectively come into sliding contact with the brush.

The sector gear 14 has a pin 14a provided thereon, extending in parallel with the axis of the shaft 13b. The pin 14a is fitted in an arcuate groove lob having a centre coaxial to the shaft 13b, formed in the camera body 10.

The pin 14a and the arcuate groove lob restrict the angular displacement of the sector gear 14. Namely, theterminal angular positions of the levers 13 in the opposite directions are defined by the engagement of the pin 14a with the opposite ends of the arched groove 10b. The terminal angular positions correspond to the operative position and the retracted position of the light.emitte-r 12.

In the illustrated embodiment, an overload detecting circuit of the strobe motor 16 is provided to detect any overload which is produced for example when the movement of the light emitter 12 is intercepted by an external force or the like; thereby to stop the motor 16. The overload detecting circuit is contained in the camera control circuit 20, in the illustrated embodiment. Alternatively, it is possible to stop the strobe motor 16 when the overload detecting means detects that no further rotation of the levers 13 beyond the operative position or the retracted position of the light emitter 12 occurs due to the abutment of the pin 14a with the terminal ends of the arched groove 10b. 25 The following discussion will be addressed to thecircuit arrangement of the strobe control apparatus, according to the present invention, with reference to Fig. 3. The camera control circuit 20 which generically controls the whole operation of the camera is usually comprised of a microcomputer. The camera control circuit is connected to a photometering circuit 22 which amplifies and logarithmically compresses the output of the- photometering sensor 21 which receives the object light and processes the output into predetermined photometer signals.

The camera control circuit 20 calculates the exposure factors (e.g., object brightness, shutter speed Tv, -11 diaphragm value, camera-shake l iinit shutter speed, etc.) in accordance with a predetermined algorism, based on data, such as film sensitivity data and the photometer signals output from the photonietering circuit 22.

The camera control. circuit 20 reads lens data issued by a lens ROM 23 (or CPU) provided in a photographing lens attached to the camera body in accordance with a serial communication. Based on the read lens data, the kind of a lens attached to the cartiera body, a focal length of the lens, a minimum diaphragm value and an open djaphragm value thereof, etc., can be obtained. Note that the- camera control circuit 20 also serves as a lens data input means. The serial communication is carried out through the electrical connection of a plurality of contacts provided on a mount 24To the camera control circuit 20 are connected contacts of a hot shoe to which an external strobe 25 can be detachably attached- In case of an external strobe 25 having a communication function, the strobe data is input: from the external strobe 25 to the camera control circuit 20 through the hot shoe 26. The strobe data includes for example dctita which determines whether the external strobe is adaptable to the camera body 10, that is, whether the external strobe interferes with the upward movement of the light emitter 12 and whether t lie strobe charging is completed, and the guide number. On the other hand, light emission permitting signals, trigger signals and quench signals are input to the external strobe 25 front the camera control circuit 20.

A photometer unit 27 includes a photometer sensor which converts an object image formed by the photographic lens to an electrical signal and outputs the photometering signal necessary for the detection of the object distance (amount of defocus). The camera control circuit 20 calculates the amount of defocus in accordance with the photometering signal and the lens data to perform the AF (Automatic Focusing) process for driving a focusing lens of -12the photographic lens to the focal position through an AF mechanism.

A LCD panel 29 is provided on the outer face of the camera body 10 within a finder field of view and is controlled by the camera control circuit through ail indicating circuit 28. In the illustrated embodiment, the LCD panel 29 indicates at least the permission and prohibition of light emission of the strobe- Of course, it is possible to indicate other information 011 t_he photographing function of the camera, such as exposuie program modes, shutter speed, diaphragm value, and 'lout of focus" and "in focus", etc.

To the camera control circuit 20 are also connected various switches including a plioloitte-ter switch (first switch) SWS, a release switch (second switch) SWR, a selt switch SW1, a light exiiission selecting switch SW2, an improper lens releasing switch SW3 and an upward movement detecting switch SW4, etc.

The photometer switch SWS and the release switch SWR are associated with the release button 31, so that when the release button is pushed down by a hal f step, the photometer switch SWS is made ON and when the release button is pushed down by full step, the release switch SWR is made ON, respectively. When the photometer switch SWS is made ON, the photometering circuit 22 and the object distance detecting unit 27, etc., begin operating. When the release switch SWR is made ON, the operation is changed to the release operation.

The self switch SW1 is a switch for operating the self timer, so that when the self switch SW1 is made ON, the mode changes to a self timer mode in which when the release switch SWR is made ON, the self operation starts and the release operation starts a predetermined time thereafter.

The light emission selecting switch SW2 is a switch for changing the light emission mode of the strobe. When -13no light emission selecting switch SW2 is made ON, the judgement whether the strobe light should be emitted in accordance with the brightness data of the object detected by the photometering circuit 22 and the lens data read by the ROM 23 is effected in an automatic light emission mode. Conversely, when the light emission selecting switch SW2 is inade ON, the strobe light emission is compulsively controlled in a compulsive light emission mode. In the.

compulsive light emission mode, when the calculated shutter 1 0 speed is higher than the strobe synchronous speed, the camera control circuit 20 sets the shutter spee-d upon release so as to be identical to the strobe synchronous speed.

The improper lens releasing switch SW3 is a switch to allow the selection of a mode in which the lens data read by the lens ROM 23 should be, or not be, utilized to judge the strobe light emission. The improper lens releasing switch SW3 is actuated for example when the strobe light should be compulsively emitted in spite of the angle of view of the attached lens being larger than the strobe illuminating angle.

The 'upward movement detecting switch SW4 is made ON when the light emitter 12 of the strobe shown in Fig. 1 is fully moved up to the light emitting position. It should be appreciated that the upward movement detecting switch SW4 and the limit switch 19 can be constituted by a single switch.

A strobe circuit 35 which causes the strobe (light emitting tube 36) to emit the strobe light, an auxiliary light emitting LED 37 adjacent to the light emitting tube 36, and the hot shoe 26 are connected to the camera control circuit 20. The camera control circuit 20 outputs the light emission permitting signal, the trigger signal and the quench signal to the strobe circuit 35 and the hot shoe 26, respectively. The camera control circuit 20 thus serves as a strobe control means.

The light emission permitting signal permits the -14light to be emitted when the necessary conditions for emitting the strobe light are satisfied, so that the incorporated and external strobes commence the preparatory operations for the light emission, such as strobe charging, upon receipt of the light emission permitting signal.

The trigger signal is a signal for emitting the strobe light. The quench signal is a signal for stopping the light emission when the amount of light emitted by the strobe reaches ail optimum value-. The auxiliary light emitting LED 37 emits a contrast pattern onto the object to assist the measurement of the object distance by the object clistance measuring unit 27 when the object brightness or contrast is small.

The camera control circuit 20 is also connected to a release magnet 39 which releases the mechanical charge of a mirror and shutter curtains (leading curtain and trailing curtain) when the release switch SWR is made ON, and leading and trailing curtain magnets 40 and 41 which engage with the leading curtain and trailing curtain in place of L; U the mechanical engagement and sequentially release the engagementj thereby to move the leading and trailing curtains so as to obtain a desired shutter speed, respectively.

The X contact switch SWX is a switch for emitting strobe light from the external strobe which has less no communication function and is made ON after the movement of the leading curtain ends to emit the strobe light from the external strobe through the hot shoe 26.

The strobe control apparatus of a camera of the present invention, as constructed above operates as follows (Figs. 4 and 5).

The general operation of the apparatus will be first briefly explained below.

In the strobe control apparatus of the invention, when the two requirements that firstly, the calculated shutter speed is below a predetermined value (e-g-, -Is camera-shake limit shutter speed), resulting in the necessity of the auxiliary light by the strobe and that secondarily, the photographic lens attached to the camera is adaptable to the incorporated strobe are satisfied, the light emitter 12 is moved up to the operative position to emit the light and then is moved down to the retracted position upon completion of the light emission.

For compulsive light emission, when tile- calculated shutter speed i S higher than the strobe synchronous speed, the shutter speed is set to the strobe. synchronous speed.

Upon using the incorporated strobe, if t he 1 ight emitter 12 does not move to the operative position, the emission of light of the incorporated strobe is stopped, so that the exposure is effected at an optimum shutter speed and a diaphragia value, corresponding to 4- hC_ _ opt 111111111 exposure value. with or without the emission of light by the external strobe 25 when the external strobe 25 is attached to the camera body or no external strobe is attached to the camera body, respectively.

In the illustrated embodiment, there are four light emission modes; a first mode in which both the incorporated strobe and the external strobe emit light, a second mode- in which only the external strobe emits light, a third mode in which only the incorporated strobe emits light, and a fourth mode in which no lj.ght is emitted f roin the incorporated and external strobes.

Generally speaking, since the strobe light is required when the. shutter speed is below a camera-shake limit shutter speed Tv, whether or not the strobe should be used is preferably judged in accordance with the calculatc.d shutter speed and the camerashake limit shutter speed Tv based on the focal length of the lens.

More detailed explanation for the operation of the control apparatus of the present invention will be given below with reference to the flow charts shown in Figs. 4 (4A, 4B and 4C) and 5. Note that the operation is performed in accordance with a program stored in a memory of the microcomputer of the camera control circuit 20.

When the program starts in conditions wherein a picture can be taken, for example by actuating a main switch, the camera control circuit 20 inputs the respective switch data (ON ? or OFF ?) of the switches SWS, SWR and SW1 at step S1 and waits until the photometer switch SWS is made ON (steps S1 and S3).

If the photometer switch SWS is made ON, the switch data of the light emission selecting switch SW2 is input to the microcomputer (steps S5 and S7). If the light emission selecting switch SW2 is made ON, the strobe light emission mode is changed to the compulsive light' emission mode (step S9) and if the light emission selecting switch SW2 is OFF, the stiobe light emission mode is changed to the automatic light emission mode (step S11). If the strobe light emission mode is the compulsive light emission mode, the shutter speed upon release is set to the strobe synchronous speed at which the shutter speed is synchronous with the light emission of the strobe, so that the strobe emits the light upon shutter release. on the other hand, if the mode is the automatic light emission mode, the strobe light is emitted only when it is judged that the strobe light is necessary, in accordance with the control mentioned below.

Thereafter, the camera control circuit 20 reads the lens data stored in the lens ROM 23 and signal transmission is effected between the camera body and the external strobe 25 through the hot shoe 26 (steps S11 and S13). The data stored in the lens ROM 23 includes the kind of the lens and focal length, etc. The data output from the external strobe 25 includes the characteristics thereof, such as whether or not the external strobe 25, when attached to the camera body 10, interferes with the 3 5 upward movement of the light emitter 12 toward the operative position, and the guide- number, etc. Note that -17 when the external strobe having no communicationfunction is attached to the camera body, the attachment of the external strobe is detected in accordance with signal level of the electrical contacts of the hot shoe.

The camera control circuit 20 calculates the exposure factors, such as a shutter speed in accordance with the photometer signal output front the photometering circuit 22 and the film sensitivity data, etc., at steps S15 and S17.

Thereafter, the camera control circult 20 causes the LCD panel 29 to indicate the various values set in the camera through the indicating circuit 28 (step S19)-. The indicated -information include the strobe light emission mode, whether the attached lens is correct or wrong, and whether the external stiobe is correct or' wrong, etc.

1 5 Thereafter, whether or not the self switch SW1 is made ON is checked, that is, whether or not the mode is the self tinier mode is checked at step S23. If the mode is not the self timer mode (i.e., the mode is the normal photographic mode), the control skips to step S32, and if zo the mode is the self tinier mode, whether the operation is the self' operation is checked at step S24. If the operation is not self operation, whether or not the release switch SWR is made ON is checked (step S25). if the release switch SWR is made ON, the self counter starts, that is, the self operation starts (step S26). The operation under the self timer mode is indicated by the flickering of the external LED 32 (Fig. 3) and the decrease of the self counter is performed (steps S28 and S29).

Thereafter, whether the self counter becomes 0 is checked at step S31. If the counter is not 0, the control is returned to step S1 to repeat the above mentioned operations. If the counter is 0, the control proceeds tostep S33. At step S24, if the self operation has already commenced, the control skips to stel) S28 to continue the self operation. Even in the self tinier mode, if the release switch SWR is not made ON, the control is returned from step S25 to step S1.

Conversely, if the mode is not the self Lliner mode, that is, if the mode is a normal photographic modLe, the control proceeds to step S32 from step S23 to check whether the release switch SWR is made ON. If the release switch SWR is not made ON, the control is returned to step S1 to repeat the operations of steps S1 - S23 and S32. 1 f the release switch SWR is made ON, the control proceeds to step S33.

AT step S33, whether the calculated shutter speedis below a predetermined value (e.g., camera-shake limit speed) is checked. If the calculated shutter speed is not below a predetermined value, the control skips to step S45 (AF process), since neither the main strobe light emission nor the auxiliary strobe light emission are necessary.

Conversely, if the calculated shutter speed is below a predetermined value, whether or not the external strobe is attached is checked at step S35. If no external strobe is attached, the control proceeds to step S39 to perform the process for moving the light emitter 12 upward to the operative position. If the external strobe is attached, whether or not the properties thereof meet the associated camera is checked (step S37). If the external strobe meets the camera requirements, the control is returned to step S39, and if the external strobe does not meet the camera requirements, the control skips to step S45. The terin "meet" referred to herein means that the external strobe does not interfere with the upward movement of the light -19emitter 12 to the operative position.

At step S39, the process for moving the light emitter upward is performed. As a result,: if the upward movement detecting switch SW4 is made ON, that is, if the light emitter 12 rises to the operative position, the auxiliary light emitting LED 37 lights up (step S43) and then the control proceeds to step S45 (AF process). If the upward movement detecting switch SW4 is not made ON at step S37, the control proceeds to the AF process, since no -light emission can be effected.

At step S45, the object distance is det.ected -through the object distance detecting unit 27, so that the AF process is performed through the AF mechanism to move the focusing lens (not shown) of the photographing lens to the focal position in accordance with the detected objecl distance (amount of defocus). Thereafter, whether or not the focusing lens is focused is checked at step S47. T f focusing is finished, the control proceeds to step S49.

Conversely, if no focusing is achieved at step S47, the control is returned to step S1 to repeat the above mentioned, operations until the focusing lens is moved exactly to the focal position.

The operations of step S1 -S23 -S31, S33-S47 and S1 are repeated until the object is "in focus" after the self counter becomes 0 in the self timer mode. On the other hahd, at the normal photographic mode, loop operations Sl- S23, S32- S47 and S1 are repeated until the object is "in focus" after the release switch SWRis made ON. Note that although the above discussion has been directed to a focus priority mode, when a release priority mode is used, the control proceeds to step S49 from step S45, regardless of "in focus,,.

At step S49, whether the mode is the compulsive light emission mode is checked. If the mode is the compulsive light emission mode, the control skips to step S61, since the incorporated strobe is expected to emit the strobe -20 light, regardless of the kind of the photographic lens and the existence of the external strobe. If the -mode isnot the compulsive light emission mode, the control proceeds to step S51.

At step S51, whether the calculated shutter speed is below a predetermined value is checked. If the calculated shutter speed is not below a predetermined value, the control skips to step S77 to prohibit the emission of the strobe light and to set the shutter speed upon release to be j o identical to the calculated shutter speed, since no strobe light is necessary. Thereafter, the control proceeds to step S69 to perform the exposure.

if the calculated shutter speed is below a predetermined value, whether the external strobe is attached is checked (step S53). If the external strobe- is attached, whether the external strobe meets the camera requirements is checked (step S54). If the external strobe does not meet the camera requirements, since the light emitter 12 can not move to the operative position, the control skips to step S75 to prohibit the light emission of the incorporated strobe and to set the shutter speed upon release to be identical to the strobe synchronous speed. Thereafter, the control proceeds to step S69 to perform the exposure.

If the external strobe meets the camera requirements, whether or not the parameters of the attached photographing lens meets the parameters of the incorporated strobe is checked (step S55). If the parameters of the attached photographic lens do not meet the parameters of the incorporated strobe, the control proceeds to step S75 to. prohibit the light emission of the incorporated strobe, since even if the strobe light is emitted, no object is correctly illuminated with the strobe light. Conversely, if the parameters of the attached photographic lens meets the parameters of the incorporated strobe, the control release proceeds to step S56 to permit the light emission of the -21 incorporated strobe and set the shutter speed upoll release to be identical to the strobe synchronous speed.

Thereafter, the control proceeds to step S63.

If the external strobe is not attached at step S53, whether the incorporated photographic lens meets the camera requirements is checked at step S57. If the incorporated photographic lens meets the came ra requirements, the control proceeds to step S61- I f the incorporated photographic lens does not meet the camera requirements, the control proceeds to step S59 to check whether the improper lens releasing switch SW4 is made-ON- If the improper lens releasing switch SW4 is not made 014, the control proceeds to step S77, since no incorporated strobe can emit strobe light. Conver:sel,,,-, if the iiixprope-i- lens releasing switch SW4 is made ON, the control is returned to step S61 to emit strobe light from the incorporated strobe.

At step S61, the incorporated strobe is permitted to emit strobe light and the shutter speed upon release is set to be identical to the strobe synchronous speed. Thereaftei, whether of not the upward movement detectiii(j switch SW4 is made ON, that is, whether the light emitter 12 comes to the operative position is checked at step S63. If the light emitter 12 is riot moved to the operative position, the strobe motor 26 is driven to move the light emitter up to the operative position (step S65)Thereafter, whether the upward movement detecting switch SW4 is made ON is checked (step S67).

If the upward movement detecting switch SW4 is made ON, the exposure is performed under the conditions determined in step S61 (or steps S56, S75 and S77) at stel) S69. After the exposure is completed, the light emitter12 is moved down to the retracted position, if the light emitter 12 is in the operative position (step S71).

If the light emitter 12 is not moved to the operative position for some reason at step S65, so that no upward 22movement detecting switch SW4 is made ON, the control proceeds to step S73 from step S67.

At step S73, whether the external strobe isattached is checked. If no external strobe is attached, 111c.

incorporated strobe is prohibited from emitting strobe light and the shutter speed upon release is set to be identical to the calculated shutter speed, so that the exposure is performed without emitting strobe light (steps S77 and S69). On the other hand, if the external strobe is attached, the external strobe emits the strobe light after the light emission of the incorporated- strobe is prohibited and after the shutter speed upon releasing is set to be identical to the strobe synchronous speed to perform the exposure (steps S75 and S69)._ Upon completion of the exposure, the light emitter 12 is moved down to the retracted position, if the light emitter is in the operati've position (step S71).

Fig. 5 shows a sub routine of the indicating operation. If the light emitter 12 is not in the operative position, if the external strobe 25 is not adaptahle (wrong) td the associ ated camera, and if the attached lens is not appropriate (wrong), a warning is indicated (steps S81- S87). The judgement that the light emitter 12 is not in the operative position is effected in accordance with the detection of the upward movement detecting switch SW4, as mentioned before. At the indication sub routine, the above-mentioned four light emission modes of the strobe and the set data of the camera are indicated at step S89.

As can be seen from the above discussion, according to the present invention, permission for the emission of the strobe light is determined in accordance with the object brightness and the lens data. When strobe light emission is necessary, the light emitter 12 is automatically moved to the operative position to emit strobe light upon exposure. 1 f the light emitter can not move to the operative position for some reason, for -23example, by the interference of the light emitter 12 with the external strobe, the incorporated strobe is prohibited from emitting the strobe light, and the strobe light is emitted only by the external strobe to perform the exposure at an optimum shutter speed and an optimum diaphragm value.

1f the light emitter 12 is not moved to the operative position when the external strobe is not attached, the incorporated strobe is prohibited from emi tting the strobe light, so that the exposure is effected without the strobe 19 light. Consequently, no photographing error occurs due to an abnormal illumination of the incorporated strolYe, and the possibility that a photographer may miss an exposure can be decreased. Furthermore, when a camera is used to which the external strobe can he attached, if the light emitter of the incorporated strobe can not move to the operative position, only the incorporated strobe is prohibited from emitting the strobe light and the strobe light is emitted from the external strobe, thus resulting in a normal strobe effect- Although, the light emitter 12 is supported by the retractable link mechanism having the levers 13 in the illustrated embodiment, the supporting mechanism is not limited thereto and can be made of, for example, a pop-up mechanism. Furthermore, the gear mechanism for moving the light emitter 12 between the retracted position and the operative position can be replaced with other mechanisms, such as a cam mechanism. Alternatively, the movement of the light emitter 12 from the retracted position to the operative position or from the operative position to the retracted position can be effected by a spring.

Although whether or not the strobe should be used in the automatic light emission mode is judged in accordance with the shutter speed obtained based on the object 3S brightness, etc., in the illustrated embodiment, the judgement can be simply done in accordance with the object brightness.

Figs. 6A through 6C show a modified embodiment in which the automatic light emission mode and the compulsive light emission niode can be switched without using the inodc- selection switch.

In Figs. 6A through 6C, t lie basic photographic operation is similar to that shown in Figs. 4A through 4C mentioned above, and accordingly, the same steps as those in Figs. 4A through 4C are designated with the same reference numerals as the last two digits of the 3 digit number.

In this modi f i ed embodiment, the automatic 1 ight emission mode is the initial mode. The light emitter 12 is usually held in the retracted position. When the photometering switch SWS is made ON, the exposure factor is calculated in accordance with a predetermined algorism, based on the normal object brightness data Bv and the film sensitivity, etc. It the calculated shutter speed Tv is below a predetermined value, the strobe is permitted to emit the strobe light- Conversely, if the calculated shutter speed Tv is above a predetermined value, the strobe is prohibited from emitting strobe light.

After the photometering switch SWS is made ON, when the calculated shutter speed Tv is below a predetermined value and when the necessary conditions for emitting the strobe light are satisfied, the light emitter is moved to the operative position, so that when the release switch SWR is made ON, the strobe light is emitted.

At the operative position of the light emitter 12, when the photometering switch SWS is first made OFF and is then made ON again, the compulsive light emission mode is set, so that strobe light can be emitted regardless of the calculated shutter speed, i. e., even at a high shutter speed. At the compulsive light emission mode, when the shutter speed upon releasing is higher than the strobe synchronous speed, the shutter speed is set to be identical to the strobe synchronous speed, so that the exposure can be effected at an optimum exposure value, with the strobe light.

When the photometering switch SWS is made ON and OFF at the operative position of the light emitter 12, the compulsive light emission mode is set. Also, when the light emitter 12 is manually moved to the operative position, the mode becomes the compulsive light emission mode.

To realize the above-mentioned operations, in the modified embodiment shown in Figs. 6A through 6C, the light emission mode selecting process (corresponding. to stZ_:.ps S5, S7, S9 and S10 in Fig. 4A) by the mode selecting switch SW1 is performed by the operation of steps SIOS, S107 and S109 in which the compulsive light emission mode is set only when the light emitter 12 is in the operative position. Thus, the compulsive light emission mode is automatically set when the light emitter 12 is in the operative position.

There is no step corresponding to step S32 inFig.

4B. Namely, at the normal photographing mode, the AF process and the strobe setting process are performed when the photomietering switch SWS is made ON. The state of the release switch SWR is checked immediately before the exposure process (step S169), i.e., after all the photographing preparatory operations are completed (steps S168 and S169).

When the photometering switch SWS is made ON, but the release switch SWR is not made ON, the control skips steps S105, S107 and S109 and is returned to step S111 from step S168 (steps S120 and S121). Consequently, when the light emitter 12 is in the operative position, the compulsive light emission mode is maintained. When t he light emitter 12 is not in the operative position, the automatic light emission mode is maintained. Namely, after the light emitter 12 which has been in the retracted position is 3 5 moved to the operative position, the compulsive light emission mode is automatically set when the photometering -26 switch SWS is first made OFF and is made ON again thereafter- Consequently, the mode can be switched from the automatic light emission mode to the compulsive light emission mode without the mode selecting switch SW1.

The following discussion will be directed to a third embodiment of the present invention which includes an indicating device which visibly indicates the self timer mode, regardless of the position of the object, (With reference to Figs. 7 through 12)- In the third embodiment, the elements corresponding to those in the first embodiment are designated with the same reference numerals., A self timer indicating LED 33 is provided in the light emitter 12, in parallel with the auxiliary light emitting diode (LED) 37. A condenser lens 37a. as a condensing optical system is provided in front of the auxiliary LED 37 to make it possible to illuminate a further object. A diffusion lens 38a as a diffusion optical system is provided in front of the self timer indicating LED 38 (Fig. 8). The self timer indicating LED 38 flickers when the self timer operation is commenced in the self timer mode by the camera control circuit 20. The light emitter 12 is moved to the operative position before the flickering commences.

The operation of the third embodiment as shown in Figs.

7 through 9 is be described below, with reference to the flow charts shown in Figs. 10A and 10B and Fig. 4C.

In Figs. 10A and 10B, the basic photographic operation is similar to that of the first embodiment, and accordingly, the same steps as those in Figs. 4A and 4B are designated by the same reference numerals as the last two digits of the 3 digit combination.

The operations during normal photographing are the same as those in the first embodiment. In the self timer mode., indicating LED 38 flickers so that the subject is aware-of is moved to the operative position and the self timer indicating LED 38 is flickered so that an object can learn -27the commencement of the self timer operation.

When the set time of the self timer is completed, whether or not the emission of light should be effected is judged in accordance with an exposure factor obtained in the previous photometering process, so that the exposure is performed in accordance with that judgement. Thereafter, the light emitter 12 is moved down to the retracted position.

When predetermined requirements, such as an actuation of the main switch (not shown) are satisfied to commence the program, the switch data of the switches SWS, -SWR and SW1 are input to the camera control circuit 20 and thecontrol waits for the actuation of the photometering switch SWS (steps S201 and S203).

When the photometering switch SWS is made ON, t h-- strobe light emission mode data set by the mode selecting switch SW2 is input to the control circuit to set the emission prohibiting mode, the automatic light emission mode, or the compulsive light emission mode (steps S205, S207, S208,- S209 and S210) in accordance with the mode data. When the compulsive light emission mode is set, the light emitter 12 is moved to the waiting position (step S211). - The camera control circuit 20 reads the lens 25 information stored in the lens ROM 23 to effect the transmission and reception of information between the camera control circuit and the external strobe 25 through the hot shoe 26 (steps S211 and S213). The camera control circuit 20 calculates the exposure factors, such as a shutter speed, in accordance with the photometering signal output from the photometering circuit 22 and the f i liti sensitivity, etc. (steps S215 and S217).

Thereafter, the camera control circuit 20 causes the LCD panel 29 to indicate the various values set in the camera through the indicating circuit 28 (step S219). The indicated information includes the strobe light emission -28 mode, whether the attached lens is correct or not, and whether the external strobe is correct or not, etc.

Thereafter, whether or not the mode is the self tinier mode is checked at step S23. If the mode is not the self timer mode, the control skips to step S232, whereas if the mode is the self timer mode, whether the operation is self operation is checked at step S224. If the operation is not self operation, whether or not the release switch SWR is made ON is checked (step S225). If the release switch SWR is made ON, the light emitter 12 is moved up to the operative position to start the self operation (step S226).

The operation at the self tinier mode is indicated by the flickering of the self timer indicating LED 38 (step S228) The subsequent operations are same as, those in the first embodiment.

According to the third embodiment mentioned above, since the upward and downward movements of the light emitter 12 and the flickering of the self timer indicating LED 38 are generically controlled in accordance with a judgment of whether or not the strobe should be used, or whether duxiliary light emitting LED 37 should be flickered, it may be arranged that the auxiliary light emitting LED 37 and the self timer indicating LED flicker alternately.

Although the auxiliary light emitting LED 37 and the self timer indicating LED 38 are separately provided in the third embodiment, the two LED's can be a single LED. In this latter case, an optical system which has a centre condenser lens 37b and a circumferential diffusion optical system 38b is provided in front of the auxiliary light emitting LED 37, as shown in Fig. 12.

The following discussion will be directed to a fourth embodiment of the present invention in which the indication of the self timer mode can be observed from an object to be taken even when the light emitter 12 is in the- retracted position,. ith reference to Figs. 13 through 16 (W A diffusion lens 50 is provided on the front face of the camera body 10 so as to correspond to the condenser lens 36a of the strobe light emitter 12 which is in the retracted position. The diffusion lens 50 diffuses the contrast pattern which is condensed by the condenser lens 36a. lf the light emitting element 16 emits light when the light emitter 12 is in the retracted position, the light is diffused by the diffusion lens 50, so that the diffusion lens 50 is made brighter, as viewed from the object side at 1 least in the film plane. Preferably, the diffusion lens 50 is made- of a transparent or a semi- transparent matertial, or a material colored by a conspicuous color, such as ied. Alternatively, the lens can be replaced with a slit or the 1 i ke.

The operation of the fourth embodiment is as follows.

The components corresponding to those in the first, second or third embodiment are designated with the same reference nuilierall s.

The mode selection switch SW2 is a switch for switching the strobe light emission modes. Every time the mode selection switch SW2 is made ON, the mode sequentially changes as follows:- automatic light emission mode compulsive light emission mode- emission prohibiting mode - automatic light emission mode. The "automatic light emission model' is a mode in which the emission of light of the strobe is controlled in accordance with the object brightness detected by the photometering circuit 22 and the lens data read from the lens ROM 23. The "compulsive light emission mode" is a mode in which strobe light is compulsively emitted regardless of the object brightness. The "emission prohibiting mode" is a mode in which the emission of strobe light is prohibited regardless of the object brightness.

The camera control circuit 20 sets the shutter speed upon release to be identical to the strobe synchronous speed when the calculated shutter speed is higher than the strobe -30synchronous speed in the compulsive emission mode.

The light emitting element 40 for emitting the auxiliary strobe light and indicating the self timer operation) emits the contrast pattern onto the object to assist the detection of the object distance by the AF uni t 27 when the strobe light emitter 12 is in the operative position. In the self timer mode, the light emitting element 40 flickers when the light emitter 12 is in the retracted position, so that a subject is aware of the commencement and end of the self tinier operation.

The camera as constructed above operates as -follows (Figs. 16A through 16D).

In the normal photographic mode, when the photoinetering switch SWS is x,,,.ade 'ON to start the photometering operation, whether or not the strobe should be used is judged in accordance with a calculated exposure factor- If it is judged that the strobe should be emitter 12 is moved up to the operative used, the light position to wait for the actuation of the release switch SWR. When the release switch SWR is made ON, the strobe light is "emitted from the light emitter 12 to perform the exposure at an optimum exposure value. After the exposure is completed, the light emitter 12 is moved down to the retracted position.

In the self timer mode which is set by the self timer switch 'SW1, the self timer operation starts when the release switch SWR is made ON. Consequently, the light emitting eiement 40 flickers to show the commencement of the self timer operation when the light emitter 12 is in the retracted position. When the set time period of the self timer ends, the exposure is effected at an optimum exposure value in accordance with the e2iposure factor obtained in the latest photometering operation immediately before the time ends. When it is judged that the strobe light should be emitted in accordance with the exposure factor obtained in the photometering process immediately -31 before the end of the set time of the self timer, or when the mode is the compulsive light emission mode. the light emitter 12 is moved to the operative position to cause the light emitting element 40 to flicker to indicate the self timer operation and to emit the auxiliary strobe light.

The operation will be described in more detail with reference to the flow chart shown in Figs. 16A through 16D.

After the program starts, the switch data of the switches SWS, SWR and SW1 are input to the camera control circuit 20 to wait for the actuation of the photometering switch SWS (steps S301 and S303).

When the photometering switch SWS is made ON, the emission mode data set by the mode selecting switch SW2 is input to the camera control circuit -20 (step S305) to select the automatic emission mode, the compulsive emission mode or the emission prohibition mode (steps S307, S309, S310 and S311).

Thereafter, the camera control circuit 20 reads the lens data stored in the lens ROM 23 to calculate and memorize the camera-shake limit shutter speed, based on the focal ledgth data (steps S315 and S317). The lens data stored in the lens ROM 23 includes the kind of the lens, an open diaphragm value, a minimum diaphragm value, etc., in addition to the focal length data.

Thereafter, whether or not the mode is the self timer mode (whether or not the self timer switch SW1 is made ON) is checked at step S323. If the mode is the self tinier mode, the control proceeds to step S324, and if the mode is not the self timer mode, the control skips to step S333.

At step S324, whether or not the operation is during the self timer operation is checked. If the answer is negative, whether or not the release switch SWR is made ON is checked, and if the answer is affirmative, the self timer counter starts, that is, the self timer operation starts (steps S325 and 326). Thereafter, the decrease of the self timer counter is effected, so that the control -32 proceeds to step S329 (step S328).

At step S329, whether the counted value of the self timer counter is a predetermined time before the set time of the self timer (e.g. two seconds before the set time of the self timer) is checked. If the answer is negative, the light emitting element 40 flickers in a first cycle (step S311). Thereafter, the control is returned to step S301 to repeat the above-mentioned operations. Conversely, if the answer to step S329 is affirmative, the control proceeds to step S333.

At step S333, the photometering circuit. 22 operates to perform the photometering operation. At step S335, the arithmetic operation for obtaining the shutter speed and the diaphragm value is carried out in -accordance with the photometer signal output from the photometering circuit 22 and the film sensitivity, etc.

Thereafter, whether or not the shutter speed thus obtained is below a predetermined value (e.g. the camera-shake limit shutter speed obtained at step S317) is checked at step S337. If the shutter speed is not below the predetermined value, whether or not the mode is the self timer mode is checked (steps S339). If the mode is the self timer mode, the light emitting element 40 flickers at a second cycle (short cycle) different from the first cycle mentioned above to perform the AF process (steps S340 and 341)- The flickering of the light emitting element 40 in the second cycle makes it possible for a subject to be aware that the release periodis coming to an end.

Conversely, if the mode is not the self timer mode, the AF process is carried out without driving the light emitting element 40 (steps S339 and S341).

In the AF process at step S341, the distance of the object is detected by the object distan-ce measuring unit 27. The focusing lens (not shown) of the photographic lens is moved to the focal position by the AF mechanism through a predetermined displacement (amount of defocus) in -33 accordance with the object distance thus detected.

Thereafter, the control proceeds to step S351.

If the shutter speed is below the predetermined value at step S337, the control proceeds to step S343 to drive the strobe motor 16 in order to move the light emitter 12 up to the operative position. After that, the light emitting element 36 lights up at step S345, and then an AF operation similar to the AF operation of step S341 is performed (step S347). Thereafter, the light emitting element 36 is made OFF at step S349, and then, the control proceeds to step S351. An effect equivalent to the flickering of the light emitting element 40 in the second cycle at step S340 mentioned above, is obtained by the ONIOFF operations of the light emitting. element 36 at steps S345 and S349.

At step S351, whether or not a desired object to be, taken is "in focus" is checked. If the object is 'out of focus", the control is returned to step S1 to repeat the above-mentioned operations. Conversely, if the object is "in focus", the control proceeds to step S353 when the release switch SWR is made ON in the normal photographic mode, and the control proceeds to next step S349 when the self timer counter becomes 0 in the self timer mode, respectively (step S353). Even if the object is in focus", if no release switch SWR is made ON, or if no self timer counter becomes 0, the control proceeds to step S1 to repeat the above-mentioned operations.

The above-mentioned operations upto step S353 are repeated until the self timer counter becomes 0 and the object is 91 in focus" at the self timer mode, and thereafter, the control proceeds to step S355 from step S353.

At step S355, whether or not the mode is the compulsive light emission mode is checked. If the mode is the compulsive light emission mode, the control skips to step S373, and if the mode is not the compulsive light --34 emission mode, the control proceeds to step S357.

At step S357, whether the mode is the emission prohibiting mode is checked. If the mode is the emission prohibiting mode, the control proceeds to step S389, and if the mode is not the emission prohibiting mode, the control proceeds to step S359, respectively. The operations subsequent thereto are the same as those in the first embodiment shown in Fig. 4C.

In the fourth embodiment mentioned above, to make it possible to observe the flickering of the light emitting element 40 as an auxiliary light emitting member, provided in the light emitter 12, from the side of the object even when the light emitter is in the retracted polition, a diffusion optical system 48 is provided- on the wall of the 12.5 camera body 10 so as to be opposed to the light emitting element 40. The light emitting element 40 flickers on self operation when the light emitter 12 is in the retracted position, and accordingly, the self operation can be visibly confirmed without the provision of an additional light emitting element separate from the light emitting element 40 or without raising the light emitter 12 to the operative position.

The present invention is not limited in aspect of the fourth embodiment. For instance, the material of which the diffusion plate 50 is made and the shape thereof are optional. The arrangement of the diffusion plate 50 can be varied in accordance with the condenser lens 36a of the light emitter 12. It is possible to provide a light emitting element for indicating the self operation, separate from the light emitting element for emitting the auxiliary light, in the light emitter. The first and second cycles at which the light emitting element is flickered can be optionally selected.

As can be seen from the above discussion, according to the present invention, since the self operation indicating member which can be observed from the object -35 side is provided in the strobe light emitter which moves between the retracted position and the operative position, self timer photographing can be visibly confirmed from the object side by activating the self operation indicating member during self operation while keeping the strobe light emitter in the retracted position.

Furthermore, according to the present invention, if the self operation indicating member is used also as the auxiliary light emitting member, the number of the components can be reduced, thus resulting in 'a realization of a compact and simple camera control circuit.

Claims (10)

36 CLAIMS

1. A control apparatus for a camera with incorporated strobe device movable into an operative position and provided with a control unit for the determination of exposure parameters on the basis of object brightness determined by a light measuring apparatus, wherein the control unit under selected circumstances drives the strobe device via a drive apparatus into its operative position; wherein a detection apparatus is provided to detect whether or not the strobe device is in the operative position, and wherein the control unit adjusts exposure parameters determined without taking into consideration the incorporated strobe device, when the detection apparatus does not detect the strobe device in its operative position.

2. An apparatus according to claim 1 wherein the control unit prevents light emission by the incorporated strobe device when the detection apparatus does not detect the strobe device in its operative position.

3. An apparatus according to claim 1 wherein in addition an external strobe device is provided on the camera, and wherein the control unit prevents light emission by the internal strobe device and causes the external strobe device to emit light, when the detection apparatus does not detect the strobe device in its operative position.

37

4. An apparatus according to any preceding claim wherein the control unit controls the strobe device in its operative position when the detected object brightness is below a predetermined value.

5. An apparatus according to any preceding claim wherein an exposure parameter determined by the control unit on the basis of the object brightness determined by the light measurement unit contains a shutter speed, and wherein the control unit moves the strobe device to its operative position when the determined shutter speed lies below a predetermined value.

6 An apparatus according to any preceding claim wherein the control unit causes the light emitting element to move to the retracted position after the incorporated strobe device has 1 emitted light.

7 An apparatus according to any preceding claim wherein a compulsive light emitting switch unit activates a compulsive light emitting mode in which a strobe flash is compulsively emitted, and the control unit is adapted to move the strobe device via the drive means into the operative position when the compulsory light emitting mode is activated.

8. An apparatus according to any preceding claim wherein the control unit prevents the incorporated strobe from emitting light when the detecting means does not detect that the strobe 38 device is in the operative mode.

9. An apparatus substantially as hereinbefore set forth with reference to, andlor as illustrated in, the accompanying drawings.

10. A camera comprising an apparatus as claimed in any one of claims 1 to 9.

1 zz