GB2255649A - Exposure control apparatus of camera - Google Patents

Description

2235o49 - 1 EXPOSURE CONTROL APPARATUS OF CAMERA k The present invention

relates to an exposure control apparatus of a camera having a plurality of exposure modes.

In a conventional camera having a plurality of exposure modes, a photographer can select a desired exposure mode by actuating an associated switch or button etc.

In a recent camera having modes other than the exposure modes, such as a continuous shot mode, etc., mode selection is effected by activating a plurality of switches in combination.

However, ordinary photographers do not often use all of the various exposure modes, but rather only a few specific exposure modes. Therefore, for the ordinary photographer, the need to activate several switches in combination to effect mode selection is troublesome and complicated. A photographer is therefore prevented from easily setting a desired exposure mode.

Furthermore, in a program exposure mode of a known camera, a shutter speed and a diaphragm value are automatically determined in a specific, interdependent - 2 relationship, and accordingly, a photographer cannot vary the shutter speed and diaphragm values outside of this predetermined relationship.

When a known program shift mode is actuated in a program, exposure mode, the shutter speed and the diaphragm value are always varied together while maintaining the predetermined relationship. Namely, it is impossible to vary only one of either the shutter speed or the diaphragm value in the program exposure mode, in a known exposure control system.

Therefore, in a conventional camera, if a photographer wants to vary only one of the shutter speed and the diaphragm value in the program exposure mode, it is necessary for him or her to troublesomely switch the program exposure mode to a shutter speed priority (EE) automatic exposure mode or a diaphragm priority (ES) automatic exposure mode.

In the prior art, the accuracy of the APEX values of the shutter speed and the diaphragm value was generally 4/8 (1/2) step at the manual setting and 1/8 step at the automatic setting, respectively. Namely, the accuracy of the manual setting is lower than that of the..automatic

Furthermore, the shutter speed Tv and the diaphragm value Av which can be manually set are values on an arithmetic progression having a difference of 1/2, such settina R 9 - 3 as 1 0/8, 1 4/8, 2 0/8, will be referred to as manual series values hereinafter) having an antilogarithm portion represented by 0/2 or 112. On the other hand, the shutter speed Tv and the diaphragm value Av which can be automatically set are values on an arithmetic progression having a difference of 1/8, such as 1 0/8, 1 1/8, 1 2/8, 1 3/8,..., i.e., mixed numbers (which will be referred to as auto series values or optimum value hereinaher) having an antilogarithm portion represented by 0/8, 1/8, 2/8,. ..,7/8. Consequently, upon manual setting, it is impossible to obtain values other than the manual series values which can be set in the automatic setting, such as 1 1/8, 1 2/8, etc. In addition to the foregoing, the accuracy of the exposure value Ev and the exposure values which can be set at the manual setting are 1/2 Ev and the manual series values at the manual exposure mode are 1/8 Ev and the auto series values at the automatic exposure mode i.e., mixed numbers (which and the program exposure mode, respectively.

An object of the present invention is to eliminate the above-mentioned drawbacks of a known exposure control system, having a plurality of exposure modes including program, shutter priority, diaphragm priority and bulb exposure modes etc., by providing a simple exposure control apparatus in which the exposure modes can be easily changed and a photographer can easily set optional exposure factors.

4 - According to the present invention, there is provided an exposure control apparatus of a camera including a photometering means for detecting the brightness of an object to be taken, an exposure value calculating means for calculating an optimum exposure value in accordance with the object brightness, and an exposure factor setting means for setting a pair of exposure factors having a shutter speed and a diaphragm value. The exposure control apparatus comprises a manual setting means for manually setting at least one of the exposure factors, a specific program exposure mode in which the pair of exposure factors corresponding to the optimum exposure value are.automatically set, and an exposure factor modifying means for permitting one of the associated exposure factors to be manually set by the manual setting means when the manual setting means is actuated.

With this arrangement, when the program exposure mode is selepted, the photographer can easily modify the shutter speed or the diaphragm value by actuating the first or second manual setting means without changing the exposure mode.

t Preferably, a clear switch means is provided for cancelling the operation of the first or second manual setting'means. This makes it possible to easily return the selected mode to the program exposure mode.

According to another aspect of the present invention, there is provided an exposure control apparatus of a camera including a photometering means for detecting the brightness of an object to be taken, and automatic exposure modes in which one of a pair of exposure factors having a shutter speed and a diaphragm value can be manually set while the other exposure factor is automatically adjusted to be set in accordance with the object brightness. The exposure control apparatus comprises, a specific program exposure mode in which the pair of exposure factors are automatically set in accordance with the object brightness, first and second manual setting means for manually setting the exposure factors, an exposure mode selecting means for selecting one the exposure modes, wherein the exposure modes include the automatic exposure modes and the specific program exposure mode, and an exposure mode shifting means for compulsively shifting the specific program exposure mode to the automatic exposure mode, in which the shutter speed or the diaphragm has priority, when the associated first or second manual setting means is actuated._ With this construction, when the specific program exposure mode is selected, the mode can be easily shifted to the shutter - speed priority or diaphragm priority automatic exposure mode by the first or second manual setting means.

Peferably, when the first or second manual setting means is actuated after the mode is shifted to the automatic exposure mode by the other of the f irst or second manual setting means, the exposure mode shifting means compulsively shifts the automatic exposure mode to the other automatic exposure mode. This simplifies the mode shift operation from the specific program mode to a particular automatic exposure mode.

According to still another aspect of the present invention, there is provided- an exposure control apparatus of a camera comprising a photometering means for detecting the brightness of an object to -be taken, first and second manual actuating means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value, an automatic exposure mode in which one of the exposure factors can be manually set while the other exposure factor is automatically adjusted to be set in accordance with the object brightness, a specific program exposure mode in which said exposure factors are automatically set in accordance with the object brightness, a 4 - 7 an exposure mode shifting means for compulsively shifting the S pecific program exposure mode to the automatic exposure mode, in which the shutter speed or the diaphragm can be manually set, when the associated first or second manual actuating means is actuated, and an exposure mode returning means for returning the automatic exposure mode, compulsively selected by the exposure mode shifting means, to the specific program exposure mode.

According to still another aspect of the invention, an exposure control apparatus of a camera includes a photometering means for detecting the brightness of an object to be taken, first and second manual actuating means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value, an automatic exposure mode in which one of the exposure factors can be manually set while the other exposure factor is automatically adjusted to be set in accordance with the a specific program exposure mode in factors are automatically set in object brightness, which said exposure accordance with the object brightness, an exposuremode shifting means for compulsively shifting the specific program' exposure mode to the automatic exposure mode, in which the shutter speed or the diaphragm can be manually set, when the associated first or second manual actuating means is actuated, and an indicating means having Furthermore, according to invention, an exposure control comprises a photometering hri-htness of an obiect to indicating elements which indicate the selection of the specific program exposure mode and the selection of the automatic exposure mode, which is compulsively selected by the exposure mode shifting means, respectively.

another aspect of the apparatus of a camera means for detecting the be taken, first and second manual setting means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value, an automatic exposure mode in which one- of the exposure factors can be manually set while the other exposure factor is automatically adjusted to be set in accordance with the object brightness, a specific program exposure mode in which said exposure factors are automatically set in accordance with the object brightness, an exposure mode shifting means for compulsively shifting the specific program exposure mode to the automatic exposure mode in which the shutter speed or the diaphragm can be manually set when the associated first or second manual setting means is actuated, and an exposure factor holding means for holding one of the exposure factors, which is set at the specific program exposure mode, when the specific program exposure mode is compulsively shifted to the automatic exposure mode by the exposure mode 5; - 9 shifting means.

According to still another aspect of the present invention, there is provided an exposure control apparatus of a camera comprising a photometering means for detecting the brightness of an object to be taken, first and second manual setting means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value, two automatic exposure modes in which one of the exposure factors can be manually set by the manual setting means while the other exposure factor is automatically to be set in accordance with the object brightness, and an exposure mode shifting means for compulsively shifting the automatic exposure mode, in which one of the exposure factors can be manually set, by the first or second manual setting means to the other automatic exposure mode, in which the other exposure factor can be manually set, by the other of either the first or second manual -setting means when the latter is actuated in the first mentioned automatic exposure mode.

It is also possible to provide an exposure control apparatus of a camera comprising a photometering means for detecting the brightness of an object to be taken, first and second manual setting means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value, two automatic exposure modes in which one adjusted of the exposure factors can be manually set by the manual setting means while the other exposure factor is automatically adjusted to be set in accordance with the object brightness, a specific program exposure mode in which said exposure factors are automatically set in accordance with the object brightness, an exposure factor selecting means for selecting one of the exposure modes including the specific program exposure mode and the exposure mode shifting sDecific of the exposure associated first automatic exposure mode, and an means for compulsively shifting the program exposure mode to the automatic exposure mode, in which one factors can be manually set, when the or second manual setting means is actuated, and for compulsively shifting the automatic exposure mode to the other of the two automatic exposure modes, in which the other exposure factor can be manually set, when the associated second or first manual setting means is actuated.

An exposure control apparatus of a camera according to another aspect of the present invention comprises a photometering means for detecting the brightness of an object to be taken, first and second manual setting means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value, an automatic exposure mode in which one of the exposure factors can be z given priority by actuating the first or second manual setting means while the other exposure factor automatically adjusted to be set in accordance with object brightness, and a modifying means for modifying exposure factor having priority, so that when a first the two exposure factors is manually set by the first second manual setting means at the specific exposure mode, the second of the two exposure factors modified in accordance with the object brightness the first exposure factor is fixed to a particular value, and when the second exposure factor reaches a predetermined upper or lower limit, the second exposure factor is fixed at the upper or lower limit and the first exposure factor is modified in accordance with the object brightness.

is the an of 9 or automatic is while An example of the present invention will be described below in detdil with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a single lens reflex camera to which the present invention is applied; Figures 2 and 3 are a back view and a f roll L. elevational view of a main part of a single I camera shown in Fig. 1, respectively; Figure 4 is a block diagram of a circuit arrangement of a single lens reflex camera shown in Fig. 1; Figure 5 is a flow chart of a inain operation of a lens retlex CPU, embodying the present invention; Figure 6 is a timing chart of a coiiinitirilcali(-)tj operation between present invention; Figure 7 is a flow chart of an automatic expostIle mode operation, embodying. 'the present invention; Figure 8 is a flow chart of an error coiiecliLi_ operation, embodying the present invention; Figure 9 is a flow chart of a hyper-program exposixiL- mode operation embodying the present invention; Figure 10 is a diagram of a hyperprogram exlx)stii-e mode shown in Fig. 9; Figure 11 is a flow chart of a limited 1)1-0gl-d111 exposure mode operation, embodying the present invention, a CPU and an IPU, according to C cl 0? AW Figure 12 is a diagram of a limited program expustire mode shown in Fig. 11; Figure 13 is a flow chart of a hyper-shulter speed priority automatic exposure mode operation, embodying the present invention; Figure 14 is a flow chart of a hypershulter speed priority automatic exposure mode operation, of another embodiment of the present invention; Figure 15 is a diagram of a hyper-shutter Spee-d priority automatic exposure mode shown in Figs. 13 and 14; Figure 16 is a flow chart of a))yper-diapliragiti priority automatic exposure mode operation, embodying the present invention; Figure 17 is a flow chart Drioritv automatic exDosure of a liyper-dial)lireiciiii mode operation, of another embodiment of the present invention; Figure 18 is a diagram of a liyr)(--r--diapitra(jitt j.)i-loiity automatic exposure mode- shown in Figs. 16 and 17; Figure 19 is a flow chart of a LA manual exposme mode operation, of still another embodiment of the present invention; Figure 20 is a flow chart of an LM manual exposui:e mode operation, embodying the present invention; Figure 21 is a flow chart of an LM aperture 1)rioj..ily automatic exposure mode operation, embodying Itic 13r,esulit - 14 invention; Figures 22 and 23 are flow charts of an LA bulb ancl LM bulb exposure mode operation, respectively, embodying the present invention; Figure 24 is a flow chart of an LA hyper-manueil exposure mode operation, embodying the present invention; Figure 25 is a view showing an examp 1 e of a hyper-manual select flag; Figure 26 is a flow chart of a main operation ot cAn IPU, embodying the present invention; Figure 27 is a flow chart of a coiiiniurlicdt.ic)li operation between an IPU and a taking lens, embodying the present invention; Figure 28 is a flow chart of a switch input operdlion; Figure 29 is a flow chart of a Tv electronic dicit operation; Figure 30 is a flow chart of an Av electronic dial operation; Figure 31 is a flow chart of a shutter speed changing operation as effected by a Tv electronic dial; -Figure 32 is a flow chart of a diaphragm value AV changing operation as effected by an Av electronic dial; Figure- 33 is a flow chart of a mode silitt-itig operation; Figures 34A and 34B are together a flow charl of' ci Q i; IF mode selecting operation; Figure 35 is a flow chart of a checking operation; Figure 36 is an example of data storage in a RAM of an IPU; Figure 37 is a flow chart of a memory locking operation; Figure 38 is an example of a memory locking f lag i RAM of an IPU; Figures 39A, 39B, 39C, 39D, 39E, 39F, 39G and 3911 are flow charts of an indication operation, embodying 1.11e present invention; Figure 40 is a flow chart of an Ev checking operation, embodying the present invention; Figures 41A, 41B, 41C, 41D, 41E, and 41F show an indication of an LCD panel and an indication unit within ci finder shown in various initial indication positions; Figures 42A, 42B, 42C, 4 2D, 42E, 42F, 42G and 4211 show various exposure modes indicated on an LCD panel and an indication unit within a finder; Figures 43A, 43B and 43C show various exposure modes in a lens manual mode, as indicated on an LCD panel an(] an indication unit within a finder; Figures 44A and 44B are modified flow charts of an indicating operation of a hyper-program shown in Fig. 39A, Figure 45 is a flow chart of a sub-routine of a - 16 second Tv dial checking operation; and, Figure 46 is a flow c-hart of a sub-routine of a second Av dial checking operation.

The invention will be discussed below with reference to the preferred embodiments of the present invention.

Figures 1 and 3 are a plan view and a f I-oil t. elevational view of a single lens reflex camera body having an exposure control apparatus embodying the present invention, respectively. Figure 2 is a back view of a DX code reading portion of the camera body shown in Figs. 1 and 3.

camera body 11 has a grip portion 13 which i provided, on a front end (i. e., the object side) of dii upper surface thereof, with a shutter button 15. A Tv electronic dial 17 and a n Av electronic dial 19 '1 L- c provided behind the shutter button 15 and on an uppei. cud of the back surface of the grip portion 13, respectively. Both the Tv electronic dial 17 and the Av electronic dial 19 are in the form of rotary dials which will be discussed below in detail. When the Tv electronic dial 17 and the Av electronic. dicil 19 are rotated, the shutter speed Tv, Itic diaphragm value Av and The Tv electronic dial the exposure mode can be changed.

17 and the Av electronic didl 19 R - 17 constitute part of first and second manual setting means or first and second shutter speed and diaphragm value mantial setting means, respectively.

iA clear button 23 is provided on the tipper portion otthe back surface of the camera body 11 in the vicinity of the Av electronic dial 19. A hold button 25 is provided oil the right side of the clear button 23. The clear button 23 constitutes a part of a clear switch weans.

The electronic dials 17 and 19, the clear butlon 23, and the hold button 25 are arranged so that wilen d photographer holds the camera body 11 in a normal postuie, they can be actuated by his or her thumb or forefinUei without having to shift the camera body 11.

A slidable exposure correction/ISO lever 27 and a lever 29, both being sli(lctL)Ii-t position are located slidable exposure mode/drive in opposite directions from a neutral on the top surface of the camera body pentagonal prisiti. A main switch 31 is surface of tile cainera body 11 to pentagonal prism and can be moved positions in a slidable manner.

11 to the left of cl located oil the top tile right of Ille to th ree d i f f c L-e-ii 1 DX pins DX1 -DX6 are provided in a patrone receiving chamber 33 of the camera body 11 and come into contact with DX codes, which are printed on the surface of a patrone of T filin, to thereby read the data. In particular,the DX pfins DX1 - DX6 are brought into contact with the portion of the, DX codes which represents the ISO sensitivity Sv, so as to read the data thereof.

A group of mount pins (CONT, RES/Fmin3, SI/Fmin2, Fmaxl, A/M, Fmax2, and SCK- /Fminl) are provided on a body mount 35 of the camera body 11 to effect, for example, data communication between the camera body 11 and a taking lens 65 (Figure 4). When the body mount 35 is attached to a lens mount of the taking lens, the mount pins of the body mount 35 are electrically connected to the corresponding mount pins of the taking lens, so that the camera body 11 can i:L!ad Iens data, including a minimum F number Fmin (open F number) and from the taking lens and perform data communication with a control means (ROM or CPU). The control means (ROM or CPU) is provided in the taking lc:n::

to read additional lens data, such as focal length data I-, or data representing the kind of etc. Note that a mark or a symbol, and a suffix It- is (e.g., - SCK represent an active low or an specification.

Figure 4 shows a circuit arrangement of a control unit of a camera system embodying the present invention.

The camera body 11 has CPU 41 and IPU 43 as a control means. The CPU 41 performs the fundamental photographic a maximuni F number taking lens altached, etc., with a prefix 11-11 as mentioned above) inverted value j. 1,1 this -1 calculations and control functions, such c-is the calculalion and determination of the exposure factors (i.e., diaplii-agiti value Av and shutter speed Tv), exposure control, calculation of data necessary for automatic focus control, etc. The CPU 41 also functions as a means for compulsively changing the mode, returning an exposure mode, changing a priority exposure factor, compulsively changing an expostire mode within a specific exposure mode, setting a limit valuc., holding an exposure value, manual shifting, and switching ci set mode.

The IPU 43 functions as an input interface of. 111 e' switches, such as the shutter button 15, the Tv elect-ronic dial 17, the Av electronic dial 19, etc. The IPU 43 also exposure mode setting means, a itieai-js indicators, a regulator for making the CPU 41 ON and OFF (power holdin(j), storing the set data and shuller speed functions as an controlling the power source of memory means for JL (-) i Lhe alid 11, V, etc. The IIJU 43 has a IROM 43a which stores prograiffis I(JL determining the input of the switch data, indication of t.ht! modes, communication with the CPU 41, communication wit.1i the taking lei-is, etc. The IPU 43 also has a RAM 431) which temporarily stores the set modes, the shutter speed Tv, and the diaphragm value, etc. The IPU 43 further has an 11'PVOII (E2PROM) 43c which holds the number of f i I fli, the 1 1-3 0 sensitiviLy, etc., even after the camera power sourcu i -:; - 20 turned OFF.

The IPU 43 communicates with the taking lens 65 receives lens data, such as a maximum F number Fmax, minimum F number Fmin and the focal length f, etc. The 43 communicates with the CPU 41 to transmit and receive data therebetween to control the photographic operation the indication of the data.

The output of a light receiving element 45 is logarithmically compressed by an operational amplifier 47 and a diode Dl, amplified by an amplifier 49, converted to a digital value (Bv, BV) corresponding to an apex value by an A/D converter 51, and input to the CPU 41 through inpuL ports P30 P37.

The A/D converter 51 operates at a predetermined time to input the level signals of the ports P30 - P37 to Llitt. CPU 41 which reads object brightness signals arid diciphicigni value signals set by the taking lens 65 and converLs Lfit! signals to corresponding apex values. Tire- port P40 is cin input switching control port which switches tile logarithinically compressed voltages amplifier 49 and the diaphragrii voltages set arld t heI Pli tile and ampl- i f i ed by the by a diaphragm volume 53. The diaphragm volume 53 ge-nei:at-e-s diaphragm voltage which corresponds to the value set by Ille.

photographer when rotating the diaphragm ring (not shown) of a taking lens in the manual mode.

3 Ports P10 - P14 of the CPU 41 are connected to the 6X pins DX2 - DX6. The CPU 41 checks the levels of these ports P10 - P14 at a predetermined time to read Lhe ISO sensitivity Sv. The CPU 41 then stores the input data including the diaphragm value Av, the object brightness 13v and the ISO sensitivity Sv, predetermined addresses.

A winding motor 55 winds mirror motor 57 moves a mirror of the motors 55 and 57 are through a motor drive circuit 59.

A release magnet RL engagement of the shutter to begin shutter mechanism (shutter curtain)thus mechanical engagement by the release disengageably engaged by a leading curtain etc., in a RAM 41b and rewinds the film, and a tip and down. The operations controlled by the CPU 41 releases the mechanical the release operation. A released from the magnet RL is magnet ESI an(] a trailing curtain magnet ES2, so that the movement of t.lic shutter curtain is controlled thereby. A diapliragrit magnet EE stops the stop-down operation of the the taking lens diaphragm. The operations oE these magnets are controlled by the CPU 41 through a magnet drive circuit 61.

EE pulse counter 63 generates EE pulses in association with the stop-down operation, which is in Itirit associated with the up-down movement of tile in i rro r, subsequent lo the shuller release and sends Ille outpuls 22 thereof to the port PDD of the CPU the level change of the port PDD and when the counted number reaches a value corresponding to the set diaphragm value Av, the diaphragm magnet EE is turned ON through the magnet drive circuit 61 to stop the stop-down operation thereby maintaining the diaphragm value Av.

Ports PLO- PL6 of the CPU 43 are connected to the mount pins (A/M, CONT, RES/Fmin3, SI/Fmin2, Fmaxl, - SCK_ /Fminl) thereby completing an electrical to the taking lens 65 (i.e., memory or control means thereof). The IPU 43 communicates with the taking lens 65 through the- ports PLO PL6 to read the lens data including the open F number Fmin, the maximum F number Fmax, L- I'l efocal lengLh f, etc.

The taking lens 65 has a lens auto/manual selecLioii switch 67 which switches beLween a manual diaphragm modu (lens-manual(LM) mode) and an automatic diaphragm lliodt_(lens-auto (LA) mode) in association With a diaphragm ring.

The lens auto/manual selection switch input;port PLO of the IPU 43 through IPU 43 determines the existence of 41.

The CPU 41 counts Filiax2, connection 67 is connected to an the mount pin A/M. T the manual diaphragm mode or the automatic diaphragm mode in accordance with the level of the port PLO. The "lens-auto mode" mentioned above is an automatic diaphragm mode in which the stop-down mechanism of the camera continues the stop-down operation z ZI Z 1 - 23 until. the diaphragm value becomes a predetermined value which has been set in the camera body. The "lens manual mode" mentioned above is a manual diaphragm mode in which the diaphragm value is manually set on the taking lens side. The lens-auto mode will also be referred to as a "body set" hereinafter.

Input ports PCO - PC2 and PBO - PB5 of the IPU 43 are connected to a main switch SWMAIN, a photometer swi tch SWS, a release switch SWR, an exposure mode switch SWMODE, a drive switch SWDRIVE, an exposure correcting switch SW EF, an ISO sensitivity setting switch SWISO, a clear switch SWCL and a hold switch SWHOLD, respectively. The main switch SWAIN is associated with the main switch lever 31. The

photometer switch SWS and Lhe re-lease switch SWR are associated with the shutter button 15. The switch SWS remains open until the shutter button 15 depressed by a half step at which point it is Lurnud ON. The switch SWR is turned ON when the shutter butt.on 15 is depressed by full step. The exposure mode switch swom and the dive switch SWDRIVE are associated with the exposui.e mode/drive lever 29. The exposure correcting switch SW EF and the ISO sensitivity setting switch SWISO are associated with the exposure/ISO lever 27. The clear switch SWCL and the hold switch SWHOLD remain open until their respectiveassociated buttons, clear button 23 arid hold button 25, are i s 24 effected.

The IFU 43 detects the ONIOFF state of the switches SW, mentioned above, in accordance with the input levels of -the input ports PC and PB of the IPU 43 to perform the necessary operations.

A pair of input ports PAO and PAl and another pair of input ports PA2 and PA3 of the IPU 43 are connected to the TV electronic dial 17 and the Av electronic dial 19, respectively. Each of the TV electronic dial 17 and the Av electronic dial 19 has a click-stop rotation mechanism per se known. For example, a pair of input ports PAO and PA1 are in a floating state at a click-stop position, when the electronic dials 17 and 19 are rotated in a clockwise or counterclockwise direction, the level of one of the input ports first drops to "L" and then the level of the othel:

drops to level "L", in accordance with the direction of Lhe rotation of the dials. Thereafter, the one input port, tht-level of which has dropped to level "L" prior to the otlier, is returned to the floating state prior to the other. Sincethe order of change in the level of the input ports PAO and PAl or PA2 and PA3 depends on the rotation of the dials, the IPU 43 can discriminate the direction of rotation based on the order of change.

A group of ports PLCD and PD of the IPU 43 are connected to an LCD display panel 69 and an indicator 71. The indicator c z 71 is located in the f inder. The LCD panel 69 i s controlled by the IPU 43 to indicate various photographic information, such as the exposure mode, the shutter speed TV, the diaphragm value Av, the number of remaining frames in a roll of film, the drive mode and other data (i.e., ISO sensitivity data, and exposure correcting data EF, etc.).

The indicator 71 within the finder has indicating elemenL 71a and 71b (Figure 42E) which indicate the shutter speed TV the diaphragm value AV, and an under-exposure, over-exposure or optimum exposure of the film. The indicator 71 also has an indicating element 71c which indicates whether or noL the memory is locked.

The ma i n embodying S circuit structure of the camera S YS t: c-111 the present invention, as discussed above, operates as follows. Note that the values of the shutlei speed Tv, the diaphragm value Av, and the object Bv i n the arithmetic operation discussed below ci re cA 1 those used in calculating the APEX values.

Main Operation of CPU The main operation of the CPU 41 will be discussed below with reference to the flow chart shown in Fig. 5. The main operation is carried out in accordance with the program stored in a ROM 41a of the CPU 41.

When the photometer switch SWS is turned ON after the main switch SWMAIN is turned ON, electrical power is supplied to the chart of Fig. 5 The CPU 41 step S11, and Thereafter, the brightness Bv, CPU 41 and the operation shown iii the flow is performed.

first initializes all the input ports P at then initializes the RAM 41b at sLep S12. DX code (ISO sensitivity SV), the ob_jecL and the diaphragm value Av set by the diaphragm volume 53 when in the LM mode, are inpuL to thu CPU (steps S13, S14 and S15).

Thereafter, the CPU 41 communicates with the IPLJ 43 to receive the necessary data, such as the set photographic exposure mode and the exposure factors, etc., from the 1111) 43 (step S16).

The control proceeds to step S18 in which Lhe exposure calculation is effected to obtain optimum exposure factors i 1-1 accordance with the selected photographic exposure mude, the calculation being based on the ISO sensitivity Sv and the object brightness Bv, (-- L c.

Thereafter, Lhe CPU 41 performs data communication with Lhu 2 IPU 43 to send the calculated exposure shutter speed Tv and diaphragm value Av) (step S19).

After the exposure factors are determined, tile control proceeds to step S20 where it is determined whether or not the release switch SWR is turned ON. If the release switch SWR is turned ON, effected (step S21). 1 f the OFF, the control is returned factors (i.e., to tile 1PU 43 the releasing operation is release switch SWR is turned to step S13. While the power is held (i.e., while the power continues to be supplied), the operations of step S13 to step S20 are repeated.

Data Communication with IPU The CPU 41 performs data communication with the 11.111 43. _The data communication will be explained below with reference to Fig. 6 and Table 1 (page 117).

Each of the CPU 41 and IPU 43 has terminals corresponding to CE, RCADY, SCK, and DATA which are connected to each other.

The CPU 41 raises the level of the terminal CE (not shown), so that IPU 43 is ready for communication. When 1he IPU 43 monitors the level of the terminal CE which is changed from "L" to "lC, the level of the terminal READY is dropped and then raised, so that interruption by the CPU 41 is permitted.

When the CPU 41 monitors the permission to interrupt, a clock signal is output to the terminal -SCK-(not shown), and a command is output to the terminal DATA. Upon completion of receipt of thf.- command, the IPU 43 drops and then raises the level of the terminal READY, so that the CPU 41 detects the completion of the receipt. The IPU 43 outputs data corresponding to the received command i n accordance with the clock signal sent from the terminal SCK- of the CPU 41, or receives data from the CPU 41.

When the communication of the necessary data is completed, the IPU 43 drops the level of the terminal READY. Thereafter, the CPU 41 drops the level of the terminal CE, so that the IPU 43 detects that the data communication with the CPU is completed. When the IPU 43 monitors the level drop of the terminal CE, the IPU 43 raises the level of the terminal READY to finish the dala communication.

AE Sub-routine The sub-routine for calculating the exposure (automatic exposure mode) at step S18 will be discussed below with reference to the flow chart shown in Fig. 7.

In this AE process, the DX codes representing the ISO sensitivity are converted to APEX values (film sensitiviLy Sv) at step S50. The DX codes of the ISO sensitivity m consist of 5 bit signals and are read by the five DX pins (5 bits) DX4, DX3, DX2, DX5 and DX6 which come into contact with the codes in the illustrated embodiment. The upper three bits (DX4, DX3 and DX2) constitute an integer and the lower two bits (DX5 and DX6) a decimal. For example, if Ihe decimal is MPI or '11111, the APEX value is 0/3, if tile decimal is "10", the APEX value is 1/3, and if the decimal is 11OW, the APEX value is 2/3. The decimal thus converted to the APEX value is added to the integer. For example, the ISO 100 is represented by Sv=5, since the integer "101" is converted to an APEX value "5" and Ilic, decimal "01" is converted to an APEX value "0".

Thereafter, the object brightness Bv is converted a calculating object brightness BVI) suitable calculation by using the following equation: BVI)=13v -i (step S51). Thereafter, the film sensitivity Sv arid Itic exposure correcting value Xv are converted to a calculating sensitivity SVD arid a calculating exposure correctifig valtic XVI) suitable for calculation by using the following equations, respectively (step S52):

SU=Sv- 1; XVI)=4- Xv The above-mentioned operations are effected not only to prevent the values of the calculating exposure Factors BVD, SVD, XVD from being negative, but also to unify the accuracy or precision of the exposure factors to be a I/8Ev DX code of :0 1- step.- Consequently, the APEX calculation (i.e., addition and subtraction) can be easily effected without considering the calculation accuracy. Note that since the precision of Sv and Xv is within 1/3 Ev, it is in theory impossible to convert them to values of a 1/8Ev step. To this end, Sv arid Xv are rounded to approximately 1/3Ev- and 2/3Ev to- 3/8Ev and 5/8Ev, respectively.

- Thereafter, the brightness correction value- MNI) depending on a change of the open F number, is calculated at step S53. The brightness correction value MND is adapted to correct the object brightness Bv so as to maintain the exposure on a film plane at a constant value, regardless of, for example, a change in the open F number (i.e., change in brightness of the lens) during zooming drid is d, 0 the taking lens. The brightness is input from the taking lens by IPU 43" with the taking lens (11"U-Ieiis will be discussed hereinafter, and is IPU 43 to the CPU 41 through the CPU-IPU communication at step S16.

_iThereafter, the calculating exposure value IMI) is calculated, based on the calculating object brightness BVD the calculating sensitivity SVD, the calculating exposur correcting value XVD, and the brightness correcting valti MND by using Ihe following formula; value peculiar t correction value MND communication of the communication), which transferred from the LVD=WD + SVD + XVI) + MND The CPU 41 detects the selected exposure mode arid calls the exposure factor calculating sub-routine corresponding to the selected exposure mode (steps S55-1 S55-n, S56-1- S56-ri). The diaphragm value Av and tile shutter speed Tv are then calculated in accordance with L-lie algorithm of the selected exposure mode. Thereafter, tile control is returned. If an incorrect exposure mode- is set, an error operation as described below is carried out (slep S57).

Error Operation In the error operation at step S57 (Figure 8), the calculating shutter speed TVD and the calculating diaphragm value AVD are replaced with a calculating maximum shutter speed TVDMAX and a calculating maximum diaphragni value AVDMAX, respectively, and the number PN (or Pno) of EE pulses is set at the maximum value, i.e., 225. Thereafter, the calculating shutter speed TVD (the calculating maximum shutter speed TVDMAX) and the calculating diaphragm valkie AVD (i.e., the calculating maximum diaphragm value AVDMAX) are converted to values suitable for transmission to Lhe IPU in processes labeled TVDT (TVD-TVT) and AVDT (AVD AVT), as explained in detail hereinafter (see Fig. 8). Thereafter, the control. is returned.

1 It is possible to replace one or both of Illecalculating shutter speed WD and the calculating diaphragm value AVD with a calculating minimum shutter speed TVDMIN and a calculating minimum diaphragm value AWMIN, in place of the calculating maximum shutter speed TUMAX and the calculating maximum diaphragm value AVDMAX, respectively.

Exposure Calculating Sub-routine In the illustrated embodiment, the exposure modes include a program automatic exposure mode in which the shutter speed and the diaphragm value are automatically set in accordance with the object brightness, a shutter speed priority (EE LA) automatic exposure mode (lens-auto mode-) in wiiicii the diaphragm value is automatically sat in accordance with the manually set shutter speed and obJect brightness, a diaphragm priority (ES LA) automatic exl)ostii.f..! mode in which the shutter speed is automatically set ill accordance with the manually set diaphragm value and object brightness, a manual exposure (Manual LA) and bu 11) exposure (Bulb LA) modes, and a diaphragm priority (ES LA) automatic exposure mode (lens-manual mode).

Furthermore, in the illustrated embodiment, there is a limited program (Program LIMT) automatic exposure mode, a hyper-program (Hyper Program) automatic exposure mode used as a specific program exposure mode, a hyper S 1111 t, 1 c r z - 33 priority (flyper EE) automatic exposure mode (lens-auto mode), and a hyper diaphragm priority (Ilyper ES) automatic exposure mode.

The following discussion will be directed to an exposure factor calculation process in the above-mentioned exposure modes with reference to Figs. 9 through 23.

Hyper Program The hyper program exposure mode referred to herein is a mode in which the program mode, the EE automatic exposure mode and the ES automatic exposure mode are changed by optionally selecting the hyper program exposure mode, the hyper EE automatic exposure mode, or the hyper ES automatic exposure mode. Operations of flyperprogram inode are identical to those of the ordinary progrant mode, except that the exposure mode can be varied between the above three 'iiiodes by actuating the electronic dials 17,19 or the clear button 23.

Figure 9 shows a flow chart involving the Ityper program exposure mode and the ordinary program exposure mode and Fig. 10 shows a program diagram thereof.

First, the relationship between the calculating TV1) corresponding to t lie Tv value and the calculating AVI) corresponding to the Av value is obtained by the following formula, in accordance with the formula at step S54.

p LVD=BVD+ SVD + XVD + MND =(Bv+ 7)+ (Sv - l)+ (4- Xv) + MND =(Bv+ Sv- Xv+ MND)+ 10 =Ev + 10 =Tv + Av+ 10 =(Tv+ 5 4/8)+ (Av + 4 4/8) =TVD+ AVD Here, Ev=Bv + Sv- Xv+ MND TV1)=Tv + 5 4/8... (1) AVD=Av + 4 4/8... (2) From the equations (1) between Tv and WD and between Av respective constants added to Tv and (2) are not limited to 5 4/8 two values whose sum is 10. The are selected to be approximate embodiment. Correspondences Av and AVD thus obtained are (pages 118 and 119), example:

In the program exposure mode, the optimum calculating shutter speed WD is obtained by the following equation:

TV1)=3/8 WD + 4 6/8 The calculating exposure value LVD is obtained al and (2), the relationships and AVID are obtained. The and Av in equations (1) and 4 4/8 and can be any values of to each 4/8 arid 4 other in between Tv arid TVD arid shown in Table 2 arid by 4/8 tile. between Table 3 way of c step S54. Consequently, the optimum calculating diaphragm value AVD is obtained from the result of this calculation (steps S61- S78).

The equation mentioned above is obtained from the basic formula of the program line (Tv=3/8 Ev+ 3) in which M=Tv+ 5 4/8 and AVD=Av+ 4 4/8. When the optimum calculating shutter speed WD and the optimum calculating diaphragm value are within the shutter capability range ot the camera body 11 (range between the calculating maximum shutter speed TV13MAX and the calculating minimum shutter speed MMIN) and the diaphragm capability range of the taking lens (range between the calculating maximum diaphragm value AVDMAX and the calculating diaphragm value AV13MIN), the optimum calculating speed and the optimum calculating diaphragm value dre maintained, and the EE pulse number PN, used to mainlain the diaphragm value Av of the diaphragm of the taking lens during the releasing operation, is calculated (steps IS02, S64 - S66, S68, S69, S72). The maximum shutter speed MMAX and the minimum diaphragm value AV13MIN referred to are the maximum shutter speed and the open F number, respectively. The maximum and minimum shutter speeds TVDMAX and ntinii[ttiill slititte-r- TVDMIN are peculiar to the camera body 11 and are TV1.MAX =13 (l/8000 sec. ) and WDMIN =- 5 (30 sec.) in tile illustrated embodiment, respectively. Consequently,.1 S 36 - WD=TV+ 5 4/8, the calculating maximum and minimum shutter speed WDMAX and WDMIN are represented respectively by; TVDMAX =TVMAX + 5 4/8=18 4/8 TVDMIN =TVMIN + 5 4/8=0 4/8 The calculating maximum and minimum shutter speed WDMAX and TVDMIN are stored in advance in the internal ROM 41a of the CPU 41 and are memorized at predetermined addresses of the RAM 41b during the operations.

Using the inherent maximum and minimum diaphragm values AVMAX and AVMIN and the formula (AVD=AV+ 4 4/8), L-lie calculating maximum and minimum diaphragm values AVDMAX arid AVDMIN are represented respectively by; AVDMAX =AVMAX + 4 4/8 AVDMIN =AVMIN + 4 4/8 The maximum and minimum diaphragm values AVIIAX and AVMIN are input by the communication with theLaking lulls at step S35 (Figure 27) and the calculating maximum and minimum diaphragm values AVDMAX and AVDMIN are stored i ri 1 lieinternal RAM 41b of the CPU 41 at predetermined addresses thereof.

If the object is too bright or dark to calculate the optimum exposure factors using the above-mentioned program line, the following operations are carried out.

When the object is too bright:

If the calculating shutter speed TV1) is larger LlicAn 37 - tp the calculating maximum shutter speed TVDMAX, the optimum calculating diaphragm value AVD is calculated after the calculating shutter speed WD is replaced with the calculating maximum shutter speed WDMAX (steps S62 S64).

If the optimum calculating diaphragm value AVD thus obtain,ed is within the diaphragm capability range, the E.E pulse number PN is obtained in accordance therewitli (steps S65, S66, S68 and S72).

If the optimum calculating diaphragm val.tie AVD i:; larger than the calculating maximum diaphragm value AVDMAX, the optirtium calculating shutter speed M) is recalculated after tile optimum calculating diaphragm value AVI) is replaced with the calculating maximum diaphragm v cl 1 Lle AVDMAX (steps S65 -S68). If the recalculated calculating shutter speed WD is larger than the calculating maximum shutter speed TVDMAX, it is out of the range in which optimum exposure can be obtained by any coiitl)ixialioxi of the calculating shutter speed WD and the calcii]it.iiitj diaphragm value AVD. Consequently, an Ev out-of association bit is set at "I" to indicate that the calculating shutter. speed is out of association (i.e., the allowable range), and the calculating shutter speed TV1) is then replaced with the calculating maximum shutter speed WDMAX to calculate the EE pulse number PN (steps S69 - S72). If the recalculated calculating shutter speed WD is wi thin the shu 1 Le r v capability range, since optimum exposure can be effected, the control skips steps S70 and S71 and performs tile calculation of the EE pulse number PN in accordance with the optimum calculating diaphragm value AVD (steps S69 and 72).

When the EV out-of association bit is set at '11", the shutter speed (maximum shutter speed TVMAX) and the diaphragm (maximum diaphragm value AVMAX) is indicated in the LCD display panel 69 in a flickering manner.

When the object is too dark:

If the optimum calculating diaphragm value AVD is smaller than the calculating minimum diaphragm value AVDMIN, the optimum calculating shutter speed TVD is recalculated after the calculating diaphragm value AVD replaced with the calculating minimum diaphragm va I tie AVDM1N. If the recalculated calculating shutter speed TVD range, the value i s PN is set at 0, as Lhe diaphragm is an open F number (steps S73- S75, S78).

If the optimum calculating shutter speed TVD smaller than the calculating minimum shutter speed TVDMIN, under-exposure conditions exist, and accordingly, the Ev bit is set at shutter speed TVD is replaced with the calculating minimum shutter speed TVDMIN. Thereafter, the EE pulse number 11N is within the shutter capability held and the EE Dulse number out-of association 1 c S is "P' and the calculatina g h, is set at 0 (steps S75S78). TVD and AVD are stored at predetermined addresses of the RAM 41b and are utilized Lo control the shutter speed and diaphragm value when releasing.

When the above-mentioned operations are completed, the calculating diaphragm value AVD and the calculating shutter speed TVD are replaced with a transferring diaphragm value AVT avid a transferring shutter spied 'I'VT, respectively (steps S79 and S80). The relationships between the calculating diaphragm value AVD and the transferring diaphragm value AYr and between the calculating shutter speed I'VD and the transferring shutter speed TVT are as follows.

TVT=TVD+ 10 4/8 AVT=AVD Although TVT and AVT are not rounded in the aboveequations, TVT and AVT are rounded in the actual operation.

The transfercing shutter speed TVT and L 11 c.

transferring diaphragm value AVT are data of a 1/2Ev step.

Namely, when this data is transferred from the CPU 41 to IPU 43, the calculated values of a 1/8Ev step are rounded to 1/2Ev. This is because the data is used only to indicate the necessary information in the IPU 43, so thal acc-,tji-cic-y greater than a 1/2Ev step is unnecessary. Tables 2 an(] 3 mentioned above show indicating sections corresponding to - 40 the values of WD and AVD by way of example.

Thus, the operation of the program exposure mode is finished and the program line (diagram) shown as a solid line in Fig. 10 is obtained.

1 9 Limited Program Exposure Mode Figure 11 shows a sub-routine of the limited program exposure (automatic exposure) mode in which a photographer can set the calculating minimum and maximum shutter speeds TVD1 and TVD2 and the calculating minimum and maximum diaphragm values AVD1 and AVD2, respectively. The operational flow in this sub-routine is similar to that of the spb-routine of the program exposure mode except for tile following points. Namely, in the subroutine shown i n 1. ig.

11, the calculating minimum and maximum diaphragm values AVDMIN and AVDMAX are replaced with the set ininimum and maximum diaphragm values AVD1 and AVD2, respectively (steps S85, S93, S86, S87), and the calculating minimum and maximum shutter speeds WDMIN and WDMAX are replaced wit-ii the set minimum and maximum shutter speeds TVD1 anti 'I'VD2, respectively (steps S95, S97, S82,S83, S89, S91). 'Pile program diagram of the limited program exposure mode is shown in Fig. 12.

The calculating minimum and maximum diaphragm values AVDMIN and AWMAX, and the calculating minimum and maximum shutter speeds TVDMIN and WDMAX are set by actuating the hold button 25 and rotating the Tv electronic dial 17 and the Av electronic dial 19 when the limited program exposure mode has been selected. The setting operation shown in the flow chart of Figs. 39C and 39D will be discussed in 1 detail hereinafter.

Hyper-EE Automatic Exposure Mode Figure 13 shows a flow chart of the hyper-shutter priority (HyperEE) automatic exposure mode. The program diagram thereof is shown as a dotted- dashed line in Fig. 10.

The operation for calculating the exposure factors at the hyper-shutter priority automatic exposure mode is basically the same as the operation of the ordinary shutter priority automatic exposure mode (lens-auto mode), except that the exposure mode can be changed by actuating the electronic dials 17, 19 or the clear button 23.

The hyper-EE automatic exposure mode i'! an EE automatic exposure mode which is compulsively selecled when the hyper program exposure mode is selected and when the Tv electronic dial 17 has been actuated. Return from the hyper-EE automatic exposure mode to the hyper-program exposure mode is effected by the operation of the clear button 23 or the power switch, etc. The switch from the hyper-EE automatic exposure mode to the hyper-ES exposure mode is compulsively effected by the rotation of the Av electronic dial 19.

In the hyper-EE automatic exposure mode, the sel shutter speed WT transferred from the IPU 43 by the data communication is read and converted to the calculating m - 43 4 -4 shutter speed WD (step S101). The relationship between the transferring shutter speed WT and the calculating shutter speed WD is as follows. TVD=TVT- 10 4/8 The transferring shutter speed TVT, which is 1/2 Tv in step, is converted to the calculating shutter speed TVD, which is 1/8 Tv in step, by the above operation.

The transferring shutter speed WT is represented by data of a 1/2Ev step and is processed upon calculating, so that the decimal place thereof is identical to that of the calculating shutter speed TV1) (i.e., data which is 1/8Ev in step). Accordingly, the Tv value, which is set by the user (i. e., TVT) is set as the calculating shutter speed WD in predetermined addresses of RAM 41b.

Thereafter, the optimum calculating diaphragm value AVD is calculated using the calculating shutter speed TV1) and the calculating exposure value LVD (step S102).

If the optimum calculating shutter s 1) e. c d AVI) is within the diaphragm capability range, the values are held and the EE pulse number is calculated (steps S103, S104, S108- S110).

If the optimum calculating diaphragm value AW) is out of the diaphragm capability range, namely, if the object is too bright or dark, the following operations are performed. When the object is too bright:

If the optimum calculating diaphragm value AVD is greatgr than the calculating maximum diaphragm value AUMAX, the calculating diaphragm value AVD is replaced with the calculating maximum diaphragm value AVDMAX. This replacement causes an over-exposure condition, and accordingly, the EE pulse number PN is set after the Av out of-association bit signal is set at "P' to indicate that the optimum calculating diaphragm value AVD is out of association (steps S103, S106 S110). When the Av out-of-association bit signal is set, the number 11 22 1', indicating the diaphragm value Av in the I.CD -display paxiel 69, flickers to indicate over-exposure.

When object is too dark:

If the optimum calculating diaphragm value AVD is smaller than the calculating minimum diaphragm value AVDMIN, the calculating diaphragm value AVD is replaced with the calculating minimum diaphragm value AVDMIN. 'I'llis replacement causes an under-exposure condition, C111d accordingly, the EE pulse number PN is set at "0" after the Av out-of - association bit signal is set at "I" (steps S103--S105, S107, S108, and S110). Thus, the diagram as shown as a dotted and dashed line in Fig. 10 is obtained.

When the setting of the EE pulse number PN is finished, the calculating calculating shutter speed -Zb 1 diaphragm value AVD and the TVD are converted to Ille.

- 45 transferring diaphragm value AW and the transferring shutter speed TW to complete the operation, respectively (steps S111 and S112).

i flyper-ES Automatic Exposure Mode An embodiment of the hyper diaphragm priority (ES) automatic exposure mode (lens-auto mode) will be explained below M.ith reference to Figs. 10 and 16.

The basic operations in the hyper-ES au toma t- i c exposure mode are basically the same as the operation of the conventional ES automatic exposure mode (lensauto 0 1 body-set mode).

The hyper-ES automatic exposure mode is an E S automatic exposure mode which is compulsively selected when the hyper program exposure mode is selected and when the Av electronic dial 19 has been actuated. The return from Llic hyper-ES automatic exposure mode to the tiyi)er-1)1.-og L"Ciill exposure mode is effected by the operation of the cleaL button 23 or the power switch, etc. The switch from Lhe. hyper-ES automatic exposure mode to the hyperEE expostire mode is compulsively effected by the rotation of the Tv electronic dial 19.

In the hyper-ES automatic exposure mode, the set. diaphragm value AW transferred from the IPU 43 by the dald communication is read to convert same to the calculating 3 - 46 diaphragm value AVD (step S131). The transferring diaphragm value AVT is identical to the calculating diaphragm value AVD (i.e., AVD=AVT). _Accordingly, the diaphragm value Av manually set by - the user(i.e., AVT) is set as the calculating diaphragm value AVD at predetermined addresses of the RAM 41b.

The transferring diaphragm value AVT is represented by data which is 1/2Ev in step, and it is processed upon calculating so that the place thereof is identical to that of the calculating diaphragm value AVD (i.e., data which is 1/BEv in step).

Thereafter, the optimum calculating shutter speed 'I'VD is caIculated using the calculating exposure value AVD and the calculating exposure value LVD (step S132).

If the optimum calculating shutter speed WD is within the shutter capability range, the values are- held and the EE pulse number iscalculated in accordance with the calculating diaphragm value AVD (steps S133, S134, S138 - S140).

If the optimum calculating shutter speed TV1) is oul of the shutter capability range, namely, if the objecL is too bright or dark, the following operations are performed.

When the object is too bright:

If the optimum calculating shutter speed I'VD is greater than the calculating maximum shutter speed 'I'VDMAX, -2 -c z p - 47 the calculating shutter speed TVD is replaced with the calculating maximum shutter speed TUMAX. This rePlaceinent: causes an over-exposure condition, and accordingly, the EL pulse number PN is set after the Tv out-of -association bit signal is set at ', 1 ', to discriminate that the optimum calculating shutter speed TV is out of association (steps S133, S136S140).

When the object is too dark:

If the optimum calculating shutter speed TVD is less than the calculating minimum shutter speed TVDMIN, the calculating shutter speed TVD is replaced with t lle calculating minimum shutter speed TVDMIN. This replacement causes an underexposure condition, and accordingly, the EL pulse number PN is set at "0'1 after the Tv out-of-association bit signal is set at 1 (steps S133- S135, S137, S138 - S140).

When the EE pulse number PN is set, the caictilaiiijtj diaphragm value AVD and the calculating shulter speed TV1) are c. onverted to the transferring diaphragm value AVT and the transferring shutter speed TVT to complete the calculation of the exposure factors (steps S141 and S142), respectively. Thus, the diagram as shown as a dotted line in Fig. 10 is obtained.

Second llyper-EE or ES Automatic Exposure Mode The second hyper-EE or ES automatic exposure mode is an automatic exposure mode in which the priority exposure f actok is mod if ied only under the condition that t lie non-priority exposure factor cannot be adjusted to avoid the occurrence of under-exposure or overexposure. Namely, unlike the above mentioned hyper-EE or hyper-ES automatic exposure modes in which a change of the priority exposure factor (i.e., diaphragm value or shutter speed having a priority) does not take place even if the object is too bright or dark, the exposure factor having a priority is mod i f i ed when the modification of the exposure factor having no priority cannot be adjusted to avoid over-exposure or under-exposure.

In the second hyper-EE or ES automatic exposure mode, if the shutter speed or the diaphragm value having priority causes under-exposure or over-exposure, tile shutter Speed or the diaphragm value is modified to provide anoptlintim exposure (Figs. 15 arid 18).

The operations i n t lie second hyper-EE automatic exposure mode and the second hyper-ES automatic exposure mode will be discussed below with reference to Figs. 14 arid 17, respectively.

In the second hyper-EE automatic exposure mode, the set shutter speed WT stored in the 1PU 43 is read by Llie. operation of the Tv electronic dial 17 to convert saine to m the calculating shutter speed TVD, SO that the optimilin calculating diaphragm value AV1) is calculated in accordance with the calculating shutter speed TVD and the calculiating exposure value WD (steps S121 and S122). if the optimum calculating diaphragm value AVI) is within the diaphragm capability i.ange, the control enters step S132 of the hyper-ES automatic exposure mode as can be seen in Fig.

16 (steps S123, S125 and S127).

If the optimum calculating diaphragm value AVD maximum diaphragm enters step S132.

Consequently, a (Jotted line arid is greater than the calculating maximum d iaphragni value AVDMAX (i.e., if the object is too bright), the calculating diaphragm value AVD is replaced With tile calculating value AVDMAX, and then the control Conversely, if the optimum calculating diaphragm value AVD is less than the calculating minimum diaphragm value AM1IN (i.e., if the object is too dark), the control enters step S132 after the calculat ing diaphragm value AVD is replaced With the calculdting minimum diaphragm value AVDMIN (steps S123, S125- S127).

In step S132 of the hyper-ES automatic exposure mode(diaphragm priority automatic exposure mode), the calculating shutter speed WD is recalculated to modify the shutter speed.

the diagrams as shown by a solid Iiiic-, a two-dotted and dashed line in Fig. 15 - so - are obtained. As can be seen in Fig. 15, the oplimum exposure range is widened. This can be considered a kind of program automatic exposure mode in which the shutter priority automatic exposure mode functions in a certain exposure range.

In the second hyper-ES automatic exposure mode, the set diaphragm value AW stored in the IPU 43 is read by the operation of the Av electronic dial 17 to convert the scimu to the calculating diaphragm value AVD, so that the optimum calculating shutter speed WD is calculated in accordance with the calculating diaphragm value AVD and tile calculating exposure value LVD (steps S151 arid S152). if the optiinum calculating shutter speed WD is within the shutter capability range, the values are held arid Ille control enters step S102 of the hyper-EE atitoinatic exposure mode in Fig. 13 (steps S153, S155 and S157).

If the optimum calculating shutter speed TV1) is greater than the calculating maximum shutter speed 'I'VI)I-IAX (i.e., if the object is too bright), the shutter speed WD is replaced with the calculating maximum shutter speed TVDMAX, and then, the control enters step S102 of the shutter priority automatic exposure mode.

Conversely, if the optimum calculating shutter speed WD is less WDMIN (i. e., than the calculating minimum if the object is too dark) calculalinu shutter speed the coiit-.ic)l tz 1 9 - 51 enters step S102 after the calculating shutter speed TVD is replaced with the calculating minimum shutter speed WDMIN. In step S102, the calculating diaphragm value AVD is recalculated to modify the diaphragm value (steps S103 S112).

Consequently, the diagrams as shown by a solid line-, a dotted line and a twodotted and dashed line in Fig. 18 are obtained. As can be seen in Fig. 18, the oplimum exposure range is extended. This can be considered a kind of program automatic exposure mode in which the diaphragm priority automatic exposure mode functions in a cerldin exposure range.

Although the first and second exposure modes and the first and second exposure modes are separately explained, these modes can be performed in the same bit s.ignals of the exposure mode data included in the IPU 43 correspond above-mentioned first hyper EE automatic. hyper ES automalic. the operations camera. Namely, 2 of the E'.PROM 4-3c to those () f and second methods in the liyper-L,'1-. ' and hyper-ES automatic exposure modes, respectively. T 11 e. signal data is transferred to the CPU 41 by the CPU-11.1ti communication, so that the 2 bit signals can be determined, after the hyper-EM mode or the hyper-ES mode is delected, to switch the first or second hyper-EE and hyper-ES modes- LA Hyper-Manual Exposure Mode The hyper-manual exposure mode (body set mode) in which both the shutter speed and the diaphragm value can be manually set by the operation from the caniera body side will be discussed below with reference to Fig. 19.

In the hyper-manual exposure mode (lens-auto or body set mode), a photographer can set the exposure factors by actuating the electronic dials 17 and 19. However, when the clear button 23 is turned ON, the optimum exposure- factors are automatically calculated in accordance with the object brightness Bv, based on the algorithm identical to that of the program exposure mode. When the clear button 23 is turned OFF, the calculated exposure factors are replaced with those which are manually set.

In the LA hyper-manual exposure mode, both t heshutter speed Tv and the diaphragm value Av can be set wheri the Tv and Av electronic dials 17 and 19 are actuated, respectively. Furthermore, when the clear button 23 is turned ON, the function equivalent to the program automatic exposure mode can be performed. The set shutter speed Tv and diaphragm value Av are stored in the RAM 43b of the 1PU 43 at predetermined addresses thereof and are indicated in the Ld panel 69 and the indicator unit 71 within thefinder.

While the clear button 23 is turned ON, L111._ z v 53 calculating shutter speed TV1) and the calculating diaphragm value AV1) are calculated in accordance with the program exposure mode and the control then proceeds to step S167 (step S164).

If the clear button 23 is not turned ON, the set diaphragm value AVT and the set shutter speed TVT, transferred from the IPU 43, are converted to tile calculating diaphragm value AVD and the calculating sliutt-el speed TVD, and the control then proceeds to step S167 (steps S161 - S163).

At step S167, an exposure error A Ev is calculated by the following equation which is based on tile opti11111111 calculating exposure value LVD, obtained from the resuIt- of the actual photometering, and the exposuLe value- (AVI-) -1 TVD), which is obtained by the calculating dial)liragiii value AVD, identical to tile set calculating diaphragm vcAltic, and the calculating shutter speed 'I'VD, identical to the set calculating shutter speed:

A Ev=LVD- (AVD+ TVD) If the exposure error A Ev is within an allowable limit i - 3/8 < A Ev< + 3/8), overexposure and underexposure indication bits are set to illuminate a pair of LED exposure indicating elements 71a and 71b (Fig. 42E) in the indicator unit 71 within the finder (steps S168, S170i S171).

If the exposure error A Ev is greater than the allowable upper limit, only the overexposure indication bit is set to illuminate the indicating element 71a to thereby indicate over-exposure (steps S168 and S169). Conversely, if the exposure error A Ev is less than the allowable lower limit only the underexposure indication bit is set to illuminate the indicating element 71b to thereby indicate under-exposure (steps S168, S170 and S172). AI thotigh the allowable limit of exposure error A Ev is --f: 3/Mv in the illustrated embodiment, another limit may be selected.

Furthermore, the upper limit value and the lower 11mit value can be different from each other. It is also possible to read the latitude of the loaded film from the DX code, so that the allowable limit is determined to be identical to that of the film latitude.

Thereafter, the number PN of EE pulses is obtained from the calculating diaphragm value AVD (steps S173, S174 and S175), and the calculating diaphragm value AVI) and Lhe calculating shutter speed WD are converted to the transferring diaphragm value AW and the transferring shutter speed TVT, respectively.

When the clear button is turned OFF after being ON, the optimum exposure value in the program exposure mode is converted to the series value at steps S162 and S163, which will be discussed hereinafter, arid is S tored cl 1 W As car the clear 7 0 - 55 predetermined addresses of the RAM 41b with the accuracy equivalent to that of the manual mode.

be understood from the foregoing, since, when button 23 is turned ON in the hyper-manual exposure mode, both the shutter speed Tv and the diaphragm value Av are modified to optimum values depending on the photometering data (object brightness Bv) ill accordance with the program exposure mode, the optimum exposure veiltiE-can be manually and quickly set by a simple operation. Although the calculation of the optimum exposure factors continues while the clear button 23 is turned ON in Ille above mentioned embodiment, it is possible to calculate Illeexposure factors and store the same in the RAM 411) only when the clear button 23 is switched from OFF to ON. lit this alternative, at step S161, whether the clear button 23 is switched from OFF to ON is checked.

Second LA Hyper-manual Exposure Mode In the above mentioned embodiment, the diaphragm value Av and the shutter speed Tv are modified to those detected by the photometering operation, in accordance with the program automatic exposure mode, when the clear button 23 is turned ON. It is possible to modify only one of the exposure factors Av and Tv to an optimum value.

Furthermore, it is also possible to set the exposure factor or factors at the rounded or system Av and Tv values instead of the optimum exposure value Ev. The rounded (or system) values referred to herein mean values having steps (accuracies) which can be manually set and obtained by rounding calculated APEX values, taking into account the step -!of the APEX values calculated by the CPU 41 be-ing smaller than that of the manually set APEX values.

Selection of the optimum value and the rounded value. is determined in accordance with one bit of the- hypei manual select flag of the WPROM 43c. In the illustraled embodiment, as can be seen in Fig. 25, when the 0or(lei bits are "0" and "1", the optimum value and the romided value are selected, respectively. Furthermore, the kind cif automatic exposure inode is determined in accordance willi the first and second bits of the flag. The bit dcAtil Ccill 1M preset when the camera is shipped or can optionally be set and modified by a photographer.

a z R Fig. 24 shows a flow chart of an example in which al least one of the exposure factors is modified to an optimum value and an example in which the optimum/system value selection is effected in combination, using the data of thehyper manual select flag of the E2PROM 43c within the IPU 43. The data of the E2PROM 43c is stored in the RAM 43b of the IPU 43 upon operation, and the same data is transferred to the CPU 41 also to be stored in the RAM 41b thereof hy the CpU- IPU communication.

The state of the clear button 23 is checked at step S601. If the clear button 23 is turned ON, the Control.

proceeds to step S603 at which point the modifying mode of Tv and Av in the LA hyper-manual mode, in accordance- willi the hyper-manual select flag data, is checked. 1 n tile illustrated embodiment, the first and second bits of tile hyper-inanual select flag data are used. If the VC1 1 tie represented by the 2 bits is @'OR', "l" and "2", t proceeds to step S605 (program automatic exposure modc.

operation), step S607 (LA diaphragm priority automatic exposure mode operation), and step S609 ( LA shu 1 le I- priority automatic exposure mode operation), respectively.

If the value represented by the 2 bits is 1131', the control proceeds to step S611 without performing the exposure mode operation. Consequently, the calculating shutter speed TV1) the calculating diaphragm value AVD, the indicating slititte-i lie contr-01 58 - speed.' TVT, and the indicating diaphragm value AW are memorized in the RAM 41b of the CPU 41.

Thereafter, the system/optimum bits of the select flag data are checked at step S611. If the value represented by the bits is "0", the control proceeds to step S163 (system value setting operation) and if the value is Ill", the control proceeds directly to the sub-routine of the Manual-1 (optimum value setting operation).

The optimum value setting operation is the same cis that of the first embodiment. The system value setting operation will be explained below. The calculation of AWD and TVTD subsequent to the operations at steps S605, S60-1 and S609 means that the calculating shutter speed TV1) (S613) and the calculating diaphragm value AVD (S615) are calculated again after the calculating optimum values AVD and WD are obtained, based on the indicating opti11111111 values WT and AW which are obtained in accordance with the obtained calculating optimum values WD (=AVT) and (TVT) (by the last calculation of AVDT and WDT in sub-routine of steps S605, S607 and S609). As a result, calculating optimum diaphragm values AVD and calculating optimum shutter speed WD once obtained are replaced with the calculating system diaphragm value and the calculating system shutter speed, respectively. The operations subsequent to step 167 are identical to those in TV1) the 1 lie t he "i tk - 59 the first embodiment.

In the second embodiment mentioned above, six kinds of LA hyper-manual exposure modes (control modes) below can be selected.

Cl) Exposure control by the optimum shutter speed Tv and the optimum diaphragm value Av which are obtained when the clear button 23 is actuated in the program automatic exposure mode (first embodiment); (2) Exposure control by the system (rounded) shutter speed Tv and the system (rounded) diaphragm value Av which are obtained when the clear button 23 is actuated in the program automatic exposure mode; (13) Exposure control by the optimum diaphragm value Av which is obtained when the clear button 23 is actuated in the shutter speed priority automatic exposure mode; (,1) Exposure control by the system (rounded) dial)liragiiL value Av which is obtained when the clear button 23 is actuated in the shutter speed priority automatic exposui:e mode; (r,)) Exposure control by the optimum shutter speed Tv which is obtained when the clear button 23 is actuated in the diaphragm priority automatic exposure mode; CC)) Exposure control by the system (rounded) shultet speed Tv which is obtained when the clear button 23 is actuated in the diaphragm priority automatic exposure mode.

i speed Tv dial 17, is turned LM Hyper-Manual Exposure Mode The following discussion will be directed to 113C hyper-manual exposure mode (lens-manual mode) in which the shutter speed is set on the camera body side and the diaphragm value is set by the taking lens 65, wi th reference to Fig. 20.

In the LM hyper-manual exposure mode, the shutter is manually set by adjusting the Tv electronic but when the clear button 23 (clear switch SWCL.) ON, the shutter speed is automatically modified to an optimum value in accordance with the object brightness Bv.

If the clear button 23 is not turned ON, 111L. transferring shutter speed WT (value of 1/2EV step) sent from the IPU 43 is directly converted to the calculating shutter speed TW (steps S181 and S182). Thereaf ter, the control proceeds to step S185.

Conversely, if the clear button 23 is turned ON, Lhe shutter speed Tv is calculated in accordance with tile, lens-manual diaphragm priority (ES) which will be discussed hereinafter value which is set by the diaphragm 65 and which is input through the the A/D converter 51 by step S15 in S183). Thereafter, the selection automatic exposure mode based on the diaphragm ring of the taking lens diaphragm volume 53 an(f fig. 5 (steps S181 and of tile systeiii/ol,)liiiiiiiii IR 4; - 61 values is effected similar to the LA hyper-manual exposure mode at step S184. If the system value is selected, tile calculation of WDT is effected for the same reason as that in the LA hyper-manual exposure mode.

At step S185, the calculating diaphragm value AWRD is calculated, based on the diaphragm value Av converted to the digital value AVA/D and set by the diaphragm ring of the taking lens 65 and based oil the adjusting value AVatti peculiar to the camera body 11. Consequently, the expostire error A Ev is obtained by the following equation (st:ep S186):

A Ev=LVD- TVD - AVVRD - MND If the exposure error A Ev is within the allowable limit, the overexposure and underexposure indication bits are set. If the exposure error A Ev is greater than the upper limit value, the overexposure indication bit data is set, and if the exposure error -1 Ev is less than the 1OWCL limit value, the underexposure indication bit data is set (steps S187 - S191). Thereafter, the EE pulse number I-IN is set to the greatest value (255 in tile illustrated and the calculating shutter speed 'ITD is transferring shutter speed TVT. This completes the exposure factor setting operation (steps S192 and S193). The reason that the EE pulse number PN is set to the greatest value is to ensure that the stop-down embodiment), converted to the - 62 mechanism of the camera body 11 is driven to an extreme stop-down position corresponding to the diaphragm value set by the diaphragm ring of the taking lens 65.

As can be seen from the foregoing, with the present invention, since the shutter speed Tv is set to the optimum value or the rounded system value obtained in the diaphragm priority automatic exposure mode when the clear button 23 is turned ON in the LM hyper-manual exposure mode, the optimum exposure value can be manually and quickly obtained by a simple operation.

LM Diaphragm Priority Automatic Exposure Mode The following discussion will be addressed to the lens-manual diaphragm priority (ES) exposure niode in which the diaphragm is set by the diaphragm ring of the taking lens 65, with reference to Fig. 21.

The calculating diaphragm value AWRI) in accordance with the converted diaphragin which is obtained by converting the diaphragm by the diaphragm ring of the taking lens inherent adjusting value AVadj of the camera S201). Based on the AVVIRD value calculating shutter speed TV1) is following equation (step S202); TV1)=LVI) - AWRI) - MND is calculated value AVA/D value Av set 35, and tile body 11 (step thus obtained, Ihe calculated by Ille R Thereafter, if the calculating shutter speed TV1) is within the shutter capability range, the EE pulse number PN is set to be the largest value (steps S203, S205, S208). If the calculating shutter speed WD is greater than the calculating maximum shutter speed WMAX, or less than the calculating minimum shutter speed TVMIN, the calculating shutter speed TV1) is replaced with the calculating maximum shutter speed WMAX (steps S203 and S204), or with t lie calculating minimum shutter speed WMIN (steps S203, S20-1) and S206). Thereafter, the EE pulse number PN is set at the largest value after the Ev out-of -association bit is set (steps S207, S208).

Finally, the calculating shutter speed TV1) is converted to the transferring shutter speed to be transferred to the IPU 43 to thereby complete the ope-ration (step S209).

6 LA, LM Bulb Exposure Mode The bulb exposure mode will be discussed below with reference to Figs. 22 and 23.

In the lens-auto bulb exposure mode, 11 e transferring diaphragm value AW set by the Av electronic dial 19 is read through the CPU-1PU communication '111(1 converted to the calculating diaphragm S211). Thereafter, the EE pulse number PN corresponding lo value AVD (s 1 el) the calculating diaphragm value AVD is calculated (steps S212 and S213), the underexposure and overexposure indication bits are reset, and then, the calculating AVD is again converted to the transferring AW (steps S215 and S216). The operation is If the calculating diaphragm value AV1) is the calculating minimum pulse number PN is set at diaphragm value diaphragm value thus completed. identical to AVDMIN the EE S214).

In the lens-manual bulb exposure mode, the EE pulsenumber PN is set at the greatest value, so that tile stop-down mechanism can be driven to the diaphragm value set by the diaphragm ring of the taking lens. Thereafter, the underexposure and overexposure indication bits art! reset to finish the operation.

diaphragm value- "0" (steps S212, IPU Main Routine The above explanation has been directed to t lie operations of the CPU 41. The main routine of the IPU 43 will be explained below (Fig. 26). The photographic data, such as the manually set diaphragm value Av and shutter speed Tv, the indicating diaphragm value Av and shutter speed Tv, the selected exposure modes, the transferring diaphragm value AW and shutter speed WT transferred through the communication between the CPU 41 and the taking 19z !L carry S222) 1 1 lens, the maximum F number FNo, and the minimum F riumber FNo are stored in the internal RAM 43b of the IPU 43 at different addresses thereof.

The IPU 43 always operates when the battery is in the camera performing IPU-MAIN shown in Fig. 26. The IPU 43 first initializes the ports thereof and the RAM 43b to out the initial setting of the modes (steps S220Thereafter, the exposure mode is set to its initial mode. The initial mode is determined in accordance- with thestate of the port PLO of the IPU 43 and is either the hyper program exposure mode or the diaphragm priority automatic exposure mode corresponding to the case of the lensatito mode and the lensmanual mode, respectively.

Thereafter, intermittent operations 32ms timer (steps S223- S2292). The the following intermittent operations.

of the 32ms timer is up the switch levels of the swilcl input to the IPU 43.

are repeated by IPU 43 per f o rms Whell tile set 1j111C inputs, i.e., Ule i input ports PCO- PB5 are successively If the level of the ports is "L" (ON), the input operation corresponding to the switches and thedetermination of the type of taking lens are pertorined, so that the data, such as lens type data, etc., lens data is input to with the lens (steps the modes set by the switches or the is written into the RAM 43b, and the the IPU 43 through the coiiiiiiunicdljoii S223 - S225).If the time of the 32ms - 66 timer is not up, the control jumps to step S228 (steps S223 and S228).

Thereafter, whether or not the main switch SWMAIN turned ON is checked. If the main switch is turned OFF, Hyp-Tv flag and the Hyp-Av flag are reset to turn power-hold OFF (i.e., turn the main power source of t he 41 OFF). Thereafter, the MI, mode flag is reset (i.e., hold bit is cleared), and the control is then returned to step S223 (steps S226, S226-2, S229-2). If the main switch SWMAIN switcA switch taking operation has already begun, the photometering timer starts and the power-hold is activated to actuate the CPU 41 (steps S226, S227-1, S227-2). Thereafter, control proceeds to step S228. Conversely, it Ille photometering switch SWS is not turned ON, control skips the start of the photometering timer and the power-ho.ld operation to step S228 (steps S226, S227-1 and S228).

In step S228, the diaphragm value (F) and the shuttelspeed (S-1) etc., used in the photographing operation at the selected photographic mode are indicated in the LC1) panel 69 and the indicator unit 71 within the finder.

not the set time of 111C If the time is up, is the the CPU is turned ON, whether or not the photometering SWS is turned ON is checked. If the photometering SWS is turned ON, which usually means the picture Thereafter, whether or photometering timer is up is checked.

51 z c the power-hold is inactivated and the control is then returned to step S223. Conversely, if the time is not tip, the control is directly returned to step S223 (steps S229-1, S229-2, S223).

If the intermittent operation by the timer is interrupted by the communication with the CPU41, the communication is performed. Similarly, if the electronic dials 17 and 19 are rotated, the electronic dial selting is carried out. Note that when the main switch SW1.1AIN ib turned OFF, interruption does not occur.

Communication with Lens iThe sub-routine of the communication with the lens CPU at step S225 will be described below with re-fe-reiic(-- lo Fig. 27. The CPU 43 drops the level of the pin CONT to "L" (Logic "0"), and receives the mount pin data (open F numbel Fiiiin, the maximum F number Fmax, and Auto/Manual (A/M) dald inpul thereto (steps S31 and S32). As disclosed iii Japanust.

Patent Kokai (Unexamined Publication) No. 63-184719 f i led in the name of the assignee of the present application, the pins of the taking lens coining into contact with the pins RES/Fmin3, SI/Fmin2, Fmaxl, Fmax2 and -SCK /Fininl are connected to transistors, so that the maximum F numbet Fmax of 2 bits and the open F number Finin of 3 bits ai-(- constituted by the levels thereof in combination depending - 68 on the ON/OFF states of the transistors. The pin A/M is connected to the A/M selection switch SWA/M, so that the diaphragm Auto/Manual data of 2 bits is constituted by the ON/OFF states of the A/M selection switch.

The CPU 41 inverts the level of the pin CONT into logic "V' (i.e., level "H") to determine the presence of the automatic focusing (AF) lens KAF attached to the camera body and the kind of the attached lens (steps S33 arid S34). The taking lens which can be discriminated in the pre-sent invedtion is a manual lens K having no mount pin, an auto lens KA having the mount pins but no lens ROM, or an atit-o AF lens KAF having the mount pins and the lens ROM. If the level of the pin CONT j. S 91111, Lhe communication with the taking

lens 65 is carried out and the lens data is input (steps S34 and S35). If the levels of the iix-writ pins Fniaxl, Fmax2, Fininl, Fniin2 arid Fiiiiii3 tie all "I", a. rid if the 5 bits representing the kind of lens are I'll111", it is determined that there is a problem with the arid the and lens, and accordingly, the no the control is returned (steps level of at least one of the Fminl - Fmin3 is 11011 and discriminated is is set and the S40).

the AF lens KAF, control is returned t lens bit Nol.ens is set. S36, S37 and S38). if mount pins Fiiiaxl - Finax2 if the kind of lens the AF lens KAFLeris bit (steps S36, S39 and 1 69 - Otherwise, whether or not the mode is the lens-auto mode or the lens- manual mode is checked. If the mode is the lens-auto, the auto lens KALens bit is set and the conlrul is returned (steps S34- S36, S39, S41, S42).

If the mode is the lens-manual and if the levels of the pins Fmaxl and Fniax2 are "W' and the levels of the pins Fminl-Fmin3 are "111", the no lens flag (NoLens l)jL) is set and control is returned, since the taking lens i.:; not attached to the camera body (steps S43 and S44).

If the mode is the lens-manual mode and if the levels of the pins Fmax 1 and Fmax2 are 'TW' and the levels of 111c pins Fminl- Finin3 are MOW, the lens is the rrianual lens K, and accordingly the manual lens flag (KLens bit) is set: and the control is returned (steps S45 and S46).

Unless the levels of the pins Finaxl Fiiiax2, Flit i 111 Fmin3 are all "1" or "0", the lens is the auto lens KALens lens-manual mode, and accordingly, the ettit-o KAlens bit is set and the control is returned S4 S43, 45 and S42).

Thus, the type of lens, the lens data, and the lens Auto/Manual data are set in the memory of the IPU 43 and are transferred to the CPU 41.

Figure 28 shows a sub-routine of the switch ininit. operation at step S224. If any one of the drive swil(,li SWDRIVE, the ISO sensitivity setting switch SWISO, tAle in the - 70 exposure correcting switch SW EF switch SEMODE is turned ON, corresponding sub-routine (note:

MODE IN sub-routines are shown (steps S231 - S233). Upon operation, the mode shift operation, operation, and the memory lock operatioi the control is returned (steps S234 subroutine, the MODE IN subroutine sub-routine will be discussed hereinafter.

and the exposure mode the operation in the only the mode shift and in Fig. 28) is performed completion of the input the MODE IN are effected and S236). The mode shif 1 and the memorv lock -1 6 1R to Operation of Electronic Dials Figures 29 and 30 show the sub-routines of the operations of the Tv and Av electronic dials 17 and 19. The main routine is interrupted by these sub-routines when theTv or Av electronic dial 17 or 19 is rotated, so that any one of the ports PAO, PA1, PA2, PA3 is turned ON to set tile associated Tv or Av dial change bit (steps S271, S281).

When the Tv electronic dial 17 is rotated, tllt direction of the rotation of the Tv electronic dial 17 is checked at step S272. If the Tv electronic dial 17 is rotated in the right (clockwise) direction, the port PAO is set at "0" (the port PAl remains at 111"), the clockwise rotation bit is set, and if the Tv electronic dial 17 is rotated in the left (counterclockwise) direction, the poit PAl is set at "0" (the port PAO remains at "1"), the righL direction bit is reset, and then the control is returned i (step S273 and S274).

Similarly, when the Av electronic dial 19 is rotated, the Av dial changebit is set, and the right direction biL is set or reset (steps S282 S284). The electronic dial change bits and the right direction bits are used in the setting operations of the Av and Tv electronic dials 17 and 19 and the exposure mode selecting operation, etc., wlli(--,)i will be explained below.

i 1 Setting of Tv, Av Electronic Dials The following discussion will be addressed to the operation of the IPU 43 in accordance with the sub-routine shown in Figs. 31 and 32 when the electronic dial 17 or 19 is actuated in a specific exposure mode.

The specific exposure mode in the illustrated embodiment is either the program mode, the limited program mode, the hyper-program mode, the EE automatic mode, the lens-auto ES automatic mode, or the manual mode. Furthermore, in the illustrated embodiment, the shutter capacity of the camera is 30 sec. - 1/8000 sec. (Tv= - 5Tv -- + 13Tv) and the diaphragm capacity is the open F number Fmin (=Avmin) read from the taking lens through the maxinium F number Fmax (=Avmax). For clarification, it is assumed that Tv and Av are both 1/2Ev.

Concerning the Tv dial check, the Tv dial changebit.

is first checked. If the bit is gloss, the control is i direcCly returned, and if the bit is "P', whether or nol the right direction rotation bit is set is checked (steps S401, S402). If the right direction rotation bit is set (i.e., the Tv electronic dial 19 is rotated in the right direction), the shutter speed Tv is increased to 111C maximum shutter speed Tvmax 1/2 Tv by 1/2 Tv (sleps S402), S403, S404). Conversely, if the right direction rotation bit is reset (i. e., the Tv electronic dial 19 is rotated in 1 73 - the left direction), the shutter speed Tv is decreased 112 Tv by 1/2 Tv until the minimum shutter speed Tvmin is reached (steps S402, S405, S406). Thereafter, the Tv dial change bit is cleared and the Tv right direction rotation bit is reset (step S407).

With respect to the Av dial check, if the electjronic dial 17 is rotated in the right direction, diaphragm value Av is increased 1/2 Av by 1/2 Av until. the maximum diaphragm value Avinax is reached (steps S411--S414). Thereafter, the Av dial change bit is cleared and the Av right direction rotation bit Conversely, if the Av electronic left direction, the diaphragm value Av is decreased by 1/2 Av until the minimum diaphragm value- Aviiiin reached (steps S411, S412, S415, S416) dial change bit is cleared and rotation bit is reset (step S418) returned. The at the Tv dial set will be discussed hereinafter.

AV t lie, is reset (step S4 18). dial 17 is rotated in the 112 Av i 5 Thereaf ter, the AV the Av right, directioll and the control sub-routines of figures 31 and 32 are called and the Av dial set, respectively, which i s Selection of Exposure Mode Figures 33, 34A and 34B show sub-routines of Ille selection or modification operation of the exposure niodes. The change of the exposure modes is effected by the 1PU 4 3 1 I - 74 in accordance with the program memorized in the internal ROM 43a of the IPU 43.

Mode Shift The mode shift operation is effected to convert the IPU exposure mode to the CPU exposure mode. Namely, the IPU mode which is used in the IPU 43 is converted to the CPU mode which is used in the CPU 41. Table 4 (page 120) shows a relationship between the IPU mode NO. and the CPU mode No.

In the mode shift operation (Fig. 33), the IPU 43 checks the lens diaphragm mode. If the lens diaphragm modeis a manual mode, the CPU mode is set to be the lens-inanual mode (i.e., one of IPU inodes LB (0- 2) is set as the- CPU mode) and the control is returned (steps S621 and S623). 11: the hyper-Tv flag and the hyper-Av flag are both cleared in the lensauto mode, the CPU mode corresponds Lo the lens-auto mode plus 8, and the control is returned. If the. hyper-Tv flag is set, the CPU mode is set at "8", and the control is returned (steps S621, S625, S629 and S631).

- Mode-In The mode-in operation (step S235) is sub-routine of the SW-IN operation (step exposure mode/drive lever 29 is moved to i.e., when the exposure mode switch SWMODE during the intermittent operation by the 32 1:

performed as a S224) when the the MODE side is turned ins tinier.

e variation of the exposure modes is effected by the Tv electronic dial 17 when the exposure mode/drive lever 29 is moved to the MODE side. The exposure modes corresponding to the exposure mode numbers are shown in Table 4 mentioned above.

The mode-in operation will be described below in more detail with reference to Figs. 34A and 34B. The hyper-EL' and hyper-ES modes have no independent mode No. and have an exposure mode No. (14) which is the same as that of the hyper program. The hyper-EE and hyper-ES modes can be discrijninated by the llyp-TV and flyp-Av flags, respectively.

The taking lens in the illustrated embodiment has, an auto/manual selection switch SWA/M which is actuated by the diaphragm ring thereof. When the auto/inanual selection switch SWA/M is moved to the manual side, the diaphragm is set on the taking lens side. If the lens-manual mode is detected at step S241, the control proceeds to step S242 lo select a desired exposure mode from ainong the I.M diaphragill priority (ES) automatic exposure mode (exposure mode No. 2), the LM hyper-manual exposure mode (exposure mode No. 1) and the LM bulb exposure mode (exposure mode No. 0). The- LM diaphragm priority automatic exposure mode (exposure mode No. 2) is the initial exposure mode.

At step S242, whether or not the mode switch SWM0DE is turned ON is checked. If the mode switch SWM0DE is - 76 turned ON, whether or not the Tv electronic dial 17 is actuated (i.e., the Tv dial change bit is set) is checked.

If th pre is no change, the Tv dial change bit is reset, and the control then proceeds to the checking sub-routine.

If there is a dial change, the direction of rotation of the dial is checked (steps S243, S244 and S251).

When the Tv electronic dial 17 is rotated in the leftward direction (counterclockwise direction), i.e., if the right direction bit is 11011, the exposure mode is switched from the LM diaphragm priority mode to the LM hyper-manual mode and the LM bulb mode in this order one- by one. After the Tv dial change bit is reset, the control jumps to the check sub-routine (steps S241 S247 and S251).

When the Tv electronic dial 17 is rotated in the right direction (the right direction bit is gills), Ille exposure mode is changed in the order opposite to the above-mentioned order. After the Tv dial change bit is reset, the control jumps to the check sub-routine (steps S244, S248S251).

* If the exposure mode switch SWMODE is turned OFF, or if the Tv electronic dial 17 is not actuated (the Tv dial change bit is "0"), the Tv dial change bit is reset withoul that the control jumps lo S243 and S251).

modifying the exposure mode, so the check sub-routine (steps S242 77 Cheek Sub-routine In the cheek sub-routine (Figure 35), if one of the NOLens bit flag, the hyper-AV flag, or the hyper-Tv flag is set, the mode f indication operation is carried out after the hyper-Av flag and the hyper-Tv flag are reset. The hyper-Av flag and the hyper-Tv flag represent the AE mode.

Namely, although the hyper-EE mode and the hyper-ES mode are not included in the types of AE modes, the hyper-CE:

mode and the hyper-ES mode can be discriminated by the hyper-Av flag and the hyper-Tv flag, respectively.

Consequently, the hyper program No. 14 and the hyper Tv flag are set in the hyper-EE mode, and the hyper program No. 14 and the hyper Av flag are set in the hyper-ES mode, respectively.

To return the mode from the hyper-EE mode or hyper-ES mode to the respective hyper program modes, the hyper-Av flag or the hyper Tv flag is reset. The hyper-Av flag and the hyper-Tv flag are always reset in the lens-manual modeby the check sub-routine, and auto/manual selection switch "MANUAL" to "AUTW' accordingly, when the SWA/M is switched f rom or when the taking lens is detached from, and again attached to the camera body, the exposure mode is initialized to be the hyper-program exposure mode.

If the taking lens is the auto-lens, and accordingly, the auto/manual selection switch SWA/M is switched to "AUTW, the exposure mode is switched mode by mode in the order: program mode, hyper-program mode- limited program mode- LA bulb mode- program mode. The exposure mode is indicated (steps S241, S252 S257, S264), when the exposure mode switch SWMODE is turned ON and the Tv electronic dial 17 is rotated in the leftward direction.

If the Tv electronic dial 17 is rotated in the right direction, the exposure mode is changed in the order opposite to the above-mentioned order and is then indicated (steps S258 - S260 and S264).

If the taking lens is an auto-lens and if one of the exposure mode switch SWMODE or the Tv electronic dial 17 is turned OFF, exposure selection operation is not effected (steps S241, S251 -S253, S261). If the clear button 23 is not turned ON (i.e., clear switch SWCL is not turned ON), the latest exposure mode is indicated (steps S261 and S264).

If the clear button 23 is turned ON, and if the exposure mode is the hyper-EE mode or the hyper ES mode, the exposure mode. I f the the hyper ES Namely, since when the exposure mode hyper-ES mode, the flag is mode is initialized to be the hyper-program exposure mode is neither the hyper-EE mode nor mode, the current exposure mode is maintained. the hyper-Tv flag or the hyper-Av flag is set is the hyper-EE mode or lhe reset (steps S261 and S263).

l!' It i Consequently, when the photographer presses button 23, the hyper-EE automatic exposure mode hyper-ES automatic exposure mode is returned the clear or 1 h eto the hyper-program exposure mode.

In the exposure mode selection operation mentioned above, it is impossible to directly select the hyper-EE or hyper-ES automatic exposure mode. The selection of the hyper-EE or hyper-ES automatic exposure mode is effected by the electronic dial 17 or 19 when the liyper-progi-aiii exposure mode is selected. Namely, when the electronic dial 17 or 19 is actuated at the hyper-prograin mode, the hyper-Tv flag or the hyper-Av flag is set, so that the mode can be compulsively changed to the hyper-EE or hyperES automatic exposure mode. Furthermore, when the electronic dial 17 or 19 is actuated at the hyper-EE or hyper-ES program mode, the mode can be compulsively changed to the hyper-ES or hyper-EE automatic exposure mode, respectively.

If the clear button 23 is turned ON, the hyper-EE or hyper-ES automatic exposure mode can be changed to the respective hyper-program exposure modes. The indication of the compulsive change of the exposure mode is performed in the exposure mode indication operation which will be discussed hereinafter.

In the illustrated embodiment, the exposure modes in the lens-auto mode and the lens-manual mode are designaled comou 1 S i ve 1 v j - 80 with serial numbers. However, in practice, the exposure modes in the lens-auto mode and the exposure modes in the lens-manual mode are stored in the memory of the IPU 43 as separate data. Furthermore, the lensauto/lens-manual (A/M) data, the Hyp-Tv flag and the Hyp-Av flag are separately allocated in the memory of the IPU 43, as can be seen in Fig. 36.

The exposure mode is determined in accordance with the 3-bits for the lens-auto mode and the llyp-Tv or llyp--Av flag when the auto/manual data (A/M terminal), which is switched by the diaphragm ring of the taking lens, is "AUTO", i.e., 11011. On the other hand, when the auto/manual data (A/M terminal) is "MANUAL", i.e., "V', the exposuremode is determined in accordance with the 2-bils for the lensmanual mode.

The exposure mode data of 4-bits including bot:h the auto exposure mode and the manual exposure mode is se-iil lo the CPU 41. The correspondence in the exposure modes (111U mode and CPU mode) between the IPU and CPU is shown in Table,4.

1 Memory Lock In the memory lock operation, the exposure value Lv is locked in the memory when the hold button 25 is pressed once and the lock is released when the hold but-ton 25 is c pressed twice. Namely, every time the hold button 25 is turned ON and OFF, the memory lock of the exposure value Ev and the release thereof are repeated. For example, 3 bits within the memory lock flag data in the RAM 43b are employed in the memory lock operation. As can be seen Fig. 38, one bit is the ML mode flag (hold bit), bit the present hold switch data, and another bit hold switch data. All of these data are cleared initial state.

The memory lock operation at step S236 is perfoi:itiE-.d as follows (Fig. 37). In this operation, every time the hold switch 25 is ON and OFF, the MI, mode flag is set and reset.

First, the present hold switch data is transferred to the old hold switch data, so that the ON1OFF slate of lhe hold switch 25 is input to the present hold switch dala (steps S641 and S643). Namely, when the hold swilch is turned ON and OFF, the ML mode flag is set at "0" and reset at "P', respectively. The hold switch 25 is a normally open self-returning type. Generally speaking, since the processing time of the microcomputer is extremely short, the memory lock sub-routines are repeated several times while the photographer actuates the hold switch 25.

Thereafter, the state of the present hold switch dala is checked (step S645). Since the MI, mode flag is reset.

another the old at 1he- - 82 when the hold switch 25 is turned OFF, the control proceeds to the memory lock indication operation. Since when the 4 hold 'switch 25 is turned ON, the ML mode flag is set, the control proceeds to step S647 to check the old hold switch data. Upon the first operation when the hold switch 25 is turned ON, or upon the second and subsequent opera t ionswhen the hold switch 25 is turned OFF, the ML mode fldg is reset, and accordingly, the control proceeds to step S651. Upon the second and subsequent operations when the hold switch 25 is turned ON or upon the first operation when the hold switch 25 is turned OFF, the ML mode flag is set, and accordingly, the control proceeds to step S649.

Whether or not the ML mode flag is set is checked at step S651. If the ML mode flag is set, the flag is cleared. If the flag is cleared, the ML mode flag is set (steps S65 and S653). When the ML mode flag is set, the clirruiltexposure value Ev is stored (locked), and the power hold flag is set for 5 sec. Thereafter, the control proceeds Lo the ML indication operation (steps S655, S657 and S659). It: the ML mode flag is cleared, the control directly proceed-s to the ML indication operation (steps S651 and S653).

At step S649, whether or not the ML mode flag is set is checked. When the hold switch 25 is turned ON, the MI. mode flag is set, and accordingly, the control proceeds to step S659. Conversely, when the hold switch 25 isLL1LI1(!d I- 1 1 OFF, the ML mode flag is cleared, and accordingly, 111 e. control directly proceeds to the ML indication operation.

In the MI, indication operation, the asterisked mark indication flag is cleared. If the ML mode flag is reset, the control is returned. If the ML mode flag is set, the asterisked mark indication flag is set, and Illen Illecontrol is returned (steps S663 and S665). When the hold switch 25 is turned off, the present ML switch data, old ML switch data and the ML mode flag are all cleared.

Exposure Modification Mode- Examples of the the indicator unit 71 Indication; Mode and Set Value indication of the LCD panel 69 and within the finder are shown side by side to the left and right, respectively, in Figs. 41A through 41F, Figs. 42A through 42H, and Figs. 43A 1hroxigh 43C. In Fig. 41A, all the indicating eleiiieiit-ts li (.111 i (1 crystal segments) such as letters, marks, S Y1111)o 1 S arld figurps, etc., constituting the indication information are shown. Fig. 41B shows the indication (display) whenthe main switch SWMAIN is turned OFF. The other figures show various indication examples. The- relationship between Lhe exposure mode indication operdtion and t 11 e j 11di ccA 1. i on (display) will be described below with reference to 1-igs.

39A through 39D. The exposure mode indication operaLion is - 84 carried out by the IPU 43 in accordance with the program stored in the ROM 43a of the IPU 43.

When the taking lens attached to the camera body is an auto-lens, the control proceeds to step S302 from step S301 to perform the following operations.

F 9 I - llyper-Program Exposure Mode If the hyper-program exposure mode is set, but rione of the electronic dials 17 and 19 are actuated, the hyper-program exposure mode is indicated as shown in Fig.

42B. Namely, "Hy P" representing the hyperprogram exposure mode, "Tv 80OW' representing the initial value (l/B000 sec.) of the shutter speed, "Av 5.C (=F5.6) representing tlit.. initial value of the diaphragm value, 1122" representing the number of the photographed frames of film all appear in the LCD panel 69, and the initial values of the the shutter speed Tv and the diaphragm value Av appear in the indicator unit 71 within the finder (steps S302 through S308).

The IPU 43 reads the optimum shutter speed 111 v (transferring shutter speed TVT) and the optimum diapliragtit value Av (transferring diaphragm value AVT), calculated in the hyper-prograin provided that the and stores these addresses thereof shutter speed WT store in the RAM exposure sub-routine by the CPU 41, power of the CPU 41 is held (remains on) data in the RAM 43b at predetermined (steps S309 and S310). The transferring and the transferring diaphragm value AVT, 43b are indicated in the LCD panel 69 and the indicator unit 71 within the finder provided that the power of the CPU 41 is held.

When the Tv electronic dial 17 is actuated (i.e., when the Tv dial change bit is set at "1"), tllC-1 hypeL-TV - 86 f lag is set and the hyper-Av f lag is reset thereby actuating the hyper-EE automatic exposure mode (steps S303 and S311). Thereafter, the shutter speed Tv is modified in -accordance with the operation of the Tv electronic dial 17, with the modified shutter speed being stored in the RAM 43b at 4 predetermined address thereof and the hyper-EE automatic exposure mode and the set shutter speed Tv, etc., being indicated in the LCD panel 69 and the f indicator unit 71, as shown in Fig. S313).

The initial value of the set diaphragm value Av is ci value calculated at the hyper-program exposure mode or the hyper-EE exposure mode. Note that in Fig. 42G, the threu quarter circle which surrounds the symbol "Tv" and the- Lwu black arrows located above the symbol "Tv", in the panel, and the line underlining the numeral "4000" in finder indicator unit 71 represent the feasibility the shutter speed Tv modification by rotation of Lhe 42G (steps S31.2 and 11C1) Ille ofv electronic dial 17.

While the power of the CPU 41 is held, the IPU 43 reads (or receives) data (AVT) corresponding to the optimum diaphragm value Av (AVD), calculated in the hyper-EE automatic exposure sub-routine, and stores the data in the RAM 43b while indicating the same in the LCD panel 69, elc. (steps S314 and S315).

i 4 hyper-ES diaphragm direcyion When the Av electronic dial 19 is actuated (i.e., when the Av dial change bit is 11111), the hyper-Av flag is set and the hyper-Tv flag is reset thereby actuating the automatic exposure mode (steps S304 and S316). The value Av is varied in accordance with theof rotation of the Av electronic dial 1-9, so that the modified diaphragm value Av is stored in the- RAM 43b. The hyper-ES automatic exposure mode and the itiodified diaphragm value Av are indicated in the LCD panel 69 and the finder indicator unit 71, as shown in Fig. 4211 (steps S317 and S318).

The initial value of the set diaphragm value Av is a value calculated in the hyper-program exposure mode or the hyper-EE exposure mode. Note that in Fig. 4211, the Iliree quarter circle which surrounds the symbol "Av" and $1 black arrows located below the syinbol Av in panel, and the line underlining the nunieral "8.0" finder indicator unit 71, represent the feasibility diaphragm value Av modification by rotation of electronic dial 19.

The IPU 43 reads data (TVT) corresponding optimum shutter speed Tv (TVD) calculated in the automatic exposure sub-routine and stores the data the two t 11 e 11C1) ill t lle of 1 he the Av t: o Ille 11 Y p e r - E: S in Ille RAM 43b, provided that the power of the CPU 41 is held. The stored data is indicated in the LC1) panel 69 and Lhe findel.

i it indicator unit 71 (steps S319 and S320).

When the hyper-EE or ES automatic exposure mode is selected (i.e., when the hyperTv or hyper-Av flag has already been set), the IPU 43 stores the optirllum transferring shutter speed TVT and the optimillil transferring diaphragm value AVT, calculated in the hyperES or hyper-EE automatic exposure sub-routine by the CPU 41, into the RAM 43b and displays the same on the LeD panel 69, etc., even if neither of the electronic dials 17 or 19 are actuated. Nevertheless, the IPU 43 does riot perform the modification of the diaphragm value Av or the shutter speed Tv (steps S303- S305, S313-S315 or S303S306, S319- S320).

Thus, the photographer can rotate the Tv electronic dial 17 to switch the hyper-program exposure mode to the hyper-EE automatic exposure mode and select the slitillexspeed Tv. Similarly, it is possible for the photographer to switch the hyper-prograin exposure mode to the h y p c. r - ES automatic exposure mode and select the diaphragm value Av by rotating the Av electronic dial 19. In the illustrated embodiment, upon switching exposure modes, the op 1 i intAILL shutter speed or the optimum diaphragm value, calculated in the previous exposure mode, become the initial value of the exposure factor (i.e., the shutter speed or the diaphragm value) which can be set at the newly selected expostire J - 89 mode. The initial value of the exposure factor, set at Lhe newly selected exposure mode, can again be varied by the subsequent operation of the electronic dial 17 or 19. Alternatively, it is possible to adopt a control system in which the exposure factors are modified at the time the exposure mode is changed.

As can be understood from the above discussion, the mode can be switched from the hyper-EE automatic expostiremode or the hyper-ES automatic exposure mode to the hyper program exposure mode when the clear button 23 is turned ON. The change from the hyper-EE automatic exposure mode to the hyperES automatic exposure mode and vice versa can be effected by the rotation of the Av electronic dial 19 and the Tv electronic dial 19, respectively. In L-lie illustrated embodiment, mode is selected, when the hyper-program exposure the diagrams shown at a solid line, a dotted line and a dotted and dashed line in Fig. 10 can be easily obtained by actuating the clear button 23 and the electronic dials 17 1 As mentioned the hyper Tv and clear button 23 b and 19, respectively.

above with reference to Figs. 33 and 34, Av flags are released when either the is turned ON (steps S261- S263), tile hyper-program exposure mode is selected, the main switch SWMAIN is turned OFF or the taking lens is detached from the camera body. When the main switch SWMAIN is turned on or when the taking lens is attached, the mode isreturned to the initial mode, i.e. the hyperprogram automatic exposure mode.

Program Exposure Mode When the ordinary program exposure mode is selected, top@@, which represents the program exposure mode, is indicated in the LCD panel 69 (steps S301, S302, S321 -- S323). Furthermore, when the power hold of the CPU 41 is f effected, the IPU 43 reads the communication 'I'VT, AW data corresponding to the the optimum shutter speed Tv and the optimum diaphragm value Av, calculated in the program exposure sub-routine, and stores the data in the RAM 431). The data is indicated in in Fig. 42A (steps S324 and the LCD panel 69, S325).

etc., as shown Limited Program Exposure Mode In the 1 iiiii ted program exposure mode,, t he photographer can modify the upper and lower limits of Lhe shutter speed and the diaphragm value, both varying along the program diagrams, by actuating the electronic dials 17 and 19 and the hold switch 25.

Selection of the limited program indicated by illuminating the three surrounding the symbols "Av11 and exposure mode is quarter c i re.. 1 e"Tv", as shown in Fig. 41C 1 t (steps S461 and S462).

When the clear switch SWCL is turned ON, the lower and upper limits TV1 and TV2 of the shutter speed and Lhe lower and upper limits AVI and AV2 ofthe diaphragm value are initialized (steps S463-1, S463-2). The initial values of the shutter speed limits and the diaphragm value limits at the limited program exposure mode in the illustrated embodiment are as follows. Namely, TV1=TVMIN=30 (sec.); TV2 =TVMAX=1/8000 (sec.), AV1=AVMIN; AV2=AVMAX. These initial values are set when the limited program exposure mode is selected for the first time after the battery is charged. If the clear switch SWCL is turned OFF, the control proceeds to step S464 to check the photometering switch SWS without initializing the shutter speed limits TVI and TV2 and the diaphragm value limits AV1 and AV2. Namely, the limits set by the photographer in accordance Wi th thu following processes are initialized when the clear butLoij 23 (clear switch SWCL) is turned ON.

When the photometering switch SWS is turned when the power is held, even if the photometering SWS is turned OFF, the control proceeds to step S485 S464, S465-1). When the photometering switch SWS is OFF and when the power of the CPU 41 is held, the value is modified, and the control then proceeds to S485 steps S465-1, S465-2, S466--S486). At step ON or switch (steps turried 1 i till t- Slep S485, whether or not the power of the CPU 41 is held is checked.

If the power is held, the CPU 41 reads the optillillin diaphragm value Av and the optimum shutter speed Tv calculated at the limited program exposure mode and stores the data in the RAM 43b. The data is indicated in the LCD C panel 69, etc. Thereafter, the control is returned. -If the power is not held, the control is directly returned (sleli S486).

Change of the limit values is effected as follows (step S465-2 and steps subsequent thereto).

When the Tv electronic dial 17 is actuated, the limits of the shutter speed Tv are increased or decreased in accordance with the direction of the rotation of the Tv electronic dial 17. The limits are stored in the RAM 431_) and indicated (steps S465-2, S466).

When the hold button 25 is turned ON, the tipper and lower limits TV1 and TV2 of the shutter speed are set.

Namely, when the hold button 25 is turned ON for the úii.sl time or an odd number of times, since the ML mode flag is set, the set Tv data is modified to the lower limit TV1 (steps S467-S470), and when the hold button 25 is turned ON the second time or an even number of times, the set Tv data is modified to the upper limit TV2, and the contL-ol proceeds to step S485 (steps S467, S468, S469,S472). If 1he hold button 25 is not turned ON, change of the shutter a 0 accordance with the electronic dial 19.

- 93 speed is not effected (steps S467, S485).

On the other hand, when the Av electronic dial 19 is turned ON, the limits of the diaphragm value are changed simultaneously with the limits of the shutter speed Tv. Namely, the diaphragm value is increased or decreased in direction of rotation of tile Av The diaphragm value is consequently stored in the RAM 43b and indicated in the LCD panel 69, etc. , (steps S475, S 476). If the hold button is turned ON for the first time or an odd number of times, since the MI, mode flag is set at "I", the set Av data is modified to the lower limit AV1, and when the hold button 25 is turned ON the second time or an even number of times (M1 mode flag is "0"), the set Av data is modified to the tipper limit AV2, and the control proceeds to step S485 (steps S478, S479, S482).

Upon completion of the modification of the limits TV1 and TV2 and AV1 and AV2 of the shutter speed and the diaphragm value, the CPU 41 reads the optimum shutter speed Tv and diaphragm value Av calculated in the limited program exposure mode and stores the data in the RAM 43b, provided that the power of the CPU 41 is held (steps S485, S486). The stored data is indicated in the LCD panel 69 and 1-he indicator unit within the finder.

94 - As can limited program diaphragm value upper or lower diaphragm limit alternative, to diaphragm limits actuated, it is S467 and S477.

be understood from the foregoing, i n Lhe exposure mode, the shutter speed and the set by the photographer are changed to the shutter speed limit and the upper or lower when the hold switch 25 is turned ON. In an change the shutter speed limits or the every time the electronic dial 17 or 19 is possible to skip the operations at steps LA ES Automatic Exposure Mode When the body-set diaphragm priority (ES) automatic exposure mode (lensauto ES automatic exposure mode) is selected, the LCD panel 69 and the indicator unit 71 within the finder are displayed as shown in Fig. 42D (steps S301, S302, S321, S461, S331-S333). When the Av electronic dial 19 is rotated, the diaphragm value Av is increased or decreased in accordance with the direction of rolation thereof, stored as the set diaphragm value Av in the RAM 43b, and indicated in the LCD panel 69, etc. When the power of the CPU 41 is held, the IPU 43 outputs the diaphragm value AVT, calculated in the diaphragm priority automatic r to the CPU 41 which reads the opli11111111 shutter speed Tv calculated in the LA diaphragm priority automatic exposure sub-routine, stores the data in the RAM exposure mode 43b and indicates the same in the LCD panel 69, etc. (steps S334- S338).

LA EE Automatic Exposure Mode When the shutter speed priority (EE) automatic exposure mode is selected, the display of the LCD panel 69 and the indicator unit 71 within the finder is as shown in Fig. 42C, in which the initial value (l/8000 sec.) of the shutter speed Tv appears (steps S301, S302, S321, S331, S341- S343). When the Tv electronic dial 17 is rotated, the shutter speed Tv is increased or decreased in accordance with the direction of rotation thereof, stored as the set shutter speed Tv in the RAM 43b, and indicated in the panel 69, etc. When the power of the CPU 41 is held, LCD the IPU 43 outputs the shutter speed WT calculated in the shutter speed priority automatic exposure mode to the CPU 41 which reads the optimum transferring diaphragm value AVT calculated in the EE automatic exposure sub-routine, and stores the data in the RAM 43b and indicates the same in the LCD panel 69, etc., respectively, as shown in Fig. 42C (steps S344 - S348).

HYPer-Manual Exposure Mode In the hyper-manual exposure mode in the illustrated embodiment, the function equivalent to the calculation of - 96 the shutter speed Tv and/or the diaphragm value Av in Lile program exposure mode, the EE automatic exposure mode or the ES automatic exposure mode is achieved by actuating t lie clear button 23.

When the body-set hyper-manual exposure niode is selected, the display of the LCD panel 69, etc., is as shown in Fig. 42E (steps S301, S302, S321, S461, S331, S341, S349 - S351). When the Ev check sub-rOLI ti Be is performed, the shutter speed Tv and the diaphragm value Av which are increased or decreased in accordance with the direction of rotation of the electronic dials 17 and 19 are set in the RAM 43b and indicated in the LCD panel 69, etc., respectively (step S352).

if TVT and exposure specific the power of the CPU 41 is held, the shutter spe-ed the diaphragm value AW selected in the manual mode are output to the CPU 41, which reads Llic point LED bit calculated in exposure sub-routine, stores the same controls the illumination of the elements 71a and 71b (steps S353- S360).

the body-sel manual irl the IRAM 4 - 31), C111(1 exposure 1 ildica 11 ng LA Bulb Exposure Mode When the body-set bulb exposure mode is sele-cL-f-,d, Ilic. display of the LCD panel 69, etc., is as shown in Fig. 42P (steps S301, S302, S321, S461, S331, S341, S349, S361, S362).

4 t When the Av electronic dial 19 is rotated, the diaphraym value Av is increased or decreased in accordance with the direction of rotation of the Av electronic dial 19, stored in the RAM 43b, and indicated in the LCD panel 69 and the indicator unit 71 (steps S363 - S365).

In the body-set shutter priority exposure 1110de, diaphragm priority exposure mode, manual exposure mode and bulb exposure mode, as mentioned above, the phoLogi:apht:ti.

can set the shutter speed Tv and the diaphragm value Av by actuating the electronic dials 17 and 19. In this case, Lhe three quarter circle, the arrows, and the letters "Tv" eiiat "Av" appear in the LCD panel 69. Also, the shutter sput_-d Tv or the diaphragm value Av is underlined, as ment.ioned above. Accordingly, the photographer is alerted thaL Lh(_ shutter speed Tv and the diaphragm value Av can be, inarlLld-lly set by actuating the electronic dials 17. and 19 respectively.

Furthermore, when the hold button 25 is turned ON, the asterisk ma rk of the indicating element 7 1 C is illuminated in the indicator unit 71 within the finder, and accordingly, the photographer is alerted that Lhe memory is locked.

Lens-Manual Mode Indication of the exposure mode in the le-iis-iiiaiitj,:il - 98 mode, in which the diaphragm value is set on the taking lens side, is effected by the IPU 43 as follows:

LM hyper-Manual Exposure Mode Selection of the LM hyper-manual exposure mode js indicated in the LCD panel 69, etc., as shown in Fig. 43A (steps S301, S371 -S373). When the Tv electronic dial 17 is rotated, the shutter speed Tv which is increased or decreased in accordance with the direction of rotation thereof is stored in the RAM 43b as the set shutter speed Tv and indicated in the LCD panel 69 and the indicator unit: 71 within the finder (steps S374- S376).

Furthermore, when the power of the CPU 41 is held, the shutter speed TVT and the diaphragm value AVT selected in the manual exposure mode are output to the CPU 41 which reads the exposure indication bit set in the LA manual exposure sub-routine, stores the read data in the RAM 431), and controls the illumination of the indicating elemenis 71a and 71b (steps S377 and S378). Figs. 43A, (a), (b) and (c) designate optimum exposure, over exposure, and under exposure, respectively p i 1 1 1 LM Manual ES Automatic Exposure Mode The lens-manual diaphragm priority (ES) automatic exposure mode is indicated in the LCD panel 69, as shown in Fig. 43B (steps S301, S381- S383). If the power of the CPU 41 is held, the CPU 41 reads the shutter speed TV1' calculated in the lens-manual ES automatic exposure sub- routine and stores the data in the RAM 43b. The data is indicated in the LCD panel 69, etc., and the control is returned (steps S384, S385).

LM Bulb Exposure Mode When the lens-set bulb exposure mode is selected, the shutter speed Tv is set at "B" (bulb) which is indicated in the LCD panel 69, as shown in Fig. 43C (steps S301, S371, S381, S391, S392).

Ev Checking Sub-Routine In the Ev cheek operation, when the hold switch 25 turned ON, the optimum exposure value at that time locked, and if thereafter the or diaphragm accordance with electronic dial li (diaphragm value is is the electronic dial 17 or 19 is actuated associated exposure factor (shutter speed value) is increased or decreased ill the direction of rotation of Ille or 19, and the other exposure factor or shutter speed) is decreased or - increased, respectively, to retain the locked exposure value. In the Ev checking sub-routine at step S352, every time the electronic dial 17 and 19 are rotated by one step when the hold button 25 is turned ON, the increment or decrement of the shutter speed Tv and the diaphragm value Av by 1/2 Tv and 1/2 Av takes place, respectively. The Ev checking sub- routine will be discussed below with reference to Fig. 40.

The RAM 43b of the IPU 43 has a hold bi L corresponding to the switching operation of the hold button 25. If the hold bit is '1011, i.e., if the hold button 25 is not turned ON, the shutter speed Tv and the diaphragm value Av, which have already been set are not modified (steps S421, S437). Conversely, if the hold bit is "I", i.e., it the hold button 25 is turned ON, the following operation is performed.

If the Tv electronic dial 17 is rotated in the leftward direction (counterclockwise direction) by one step or more (i.e., the Tv change bit is "0") the shutter spe-ed Tv is decreased 1/2 Tv by 1/2 Tv and the diaphragm value Av is increased 1/2 Av by 1/2 Av until the shutter speed Tv is equal to- 5 (Tv=- 5 - 30 sec.) or the diaphragm value Av is equal to the maximum diaphragm value AVMAX (steps S422 S427). If the Av electronic dial 19 is rotated in the rightward direction (clockwise direction), the sciffie- 101 operation as above Is performed S424- S427).

If the Tv electronic dial 17 is rotated direction (clockwise direction), 9 (steps S422, S428, S429, in the rightward the shutter speed Tv is increased 1/2 Tv by 1/2 Tv and the diaphragm value Av is decreased 1/2 Av by 1/2 Av until the shutter speed Tv is equal to 13 (Tv=13- 1/8000 sec.) or the diaphragm value Av is equal to the minimum diaphragm value AVMIN (steps S422, S423, S430 -S433). If the Av electronic dial 19 is rotated in the leftward direction (counterclockwise direction), the same operation as above is performed (steps S422, S428- S433). The increased or decreased shutter speed Tv and the diaphragm value Av are stored in the RAM 43b and the Tv, Av change bits are reset (steps S434 - S437).

Thus, both the shutter speed Tv and the diaphragm value Av can be simultaneously adjusted by actuating one of the electronic dials 17 or 19 while maintaining Lhe exposure value Ev constant, when the hold button 25 is turned ON after the optimum shutter speed and the diaphragm value are manually set. For instance, on the assumption that the optimum shutter speed Tv and diaphragm value Av are 1/125 sec., and F8.0, in the hypermanual mode, respectively, if the hold button 25 is turned ON, memory is locked. Thereafter, if for example the the Tv - 102 - electronic dial 17 is rotated by two steps, the shutter speed Tv and the diaphragm value Av are changed to 1/60 sec., and F11, respectively, while maintaining exposure at the optimum value. For comparison's sake, if the Tv electronic dial Tv is actuated at the ordinary hyper-manual exposure mode, only the shutter speed is varied, resulting in a change in exposure value. This mode will be cancelled when the hold button is actuated again.

Second Exposure Mode Indication Operation The second exposure mode indicating operation (Figure 44).is different from the first exposure mode indicating operation in that the exposure mode can be changed only when Lhe electronic dials 17 or 19 are rotated by more than lwe.) steps in the hyper-program exposure mode.

When neither of the electronic dials 17 or 19 is actuated and both the hyper-Tv and hyper-Av flags are "0" in the lens-auto hyper-program, mode (i.e., when t 11 ehyper-program exposure mode is selected) the display in the LCD 69 and the indicator unit 71 within the finder is as shown in Fig. 42B (steps S501 -SS08). The transferring shutter speed TVT and the transferring diaphragm value AVT, calculated by the CPU 41, are stored in the RAM 43b (steps S509, S510), provided that the power of the CPU 41 is held.

When the hyper-EE automatic exposure mode is - 103 selected, the control proceeds from step S505 to step S514, since the hyper-Tv flag Is set. Thereafter, in steps 5514 --S518, the operations similar to those in steps S311 -S315 are effected. On the other hand, if the hyper ES automatic exposure mode is selected, the control proceeds from step S506 to step S524, since the hyper-Av flag is set. Thereafter, in steps S524 -SS28, the operations similar to those in steps S316 - S320 are effected.

When the Tv electronic dial 17 or the Av electronic dial 19 is rotated, namely, when the Tv-change bit or the Av-change bit is "1", the operations in the Tv dial or Av dial checking sub-routine are effected. As can he understood from the foregoing, in the Tv dial or Av dial checking sub-routine, the exposure mode is changed only when the Tv or Av electronic dial 17 or 19 is rotated by two or more steps in the same direction.

When the Tv or Av electronic dial 17 or 19 is rotated by one step in a predetermined direction, or when the Tv or Av electronic dial 17 or 19 is rotated thereafter by one step in the opposite direction, the control proceeds to step S505 (steps S503, S511, S505 or steps S503, S521, S505).

When the Tv electronic dial 17 is rotated by Lwo steps in the same direction, the control proceeds from slep S511 to step S512 in which, if the hyperTv flag is 11011, Lhe - 104 - Tv dial change flag is reset to permit the mode to be changed to the hyperEE automatic exposure mode and prevent the shutter speed Tv from being changed, since the hyper-EE automatic exposure mode is not selected. Thereafter, the control proceeds to step S514 (steps S512, S513 and S514). If the hyper-Tv flag is '11", since the hyper-EE automatic exposure mode is selected, the control proceeds directly to step S514 in which the shutter speed Tv can be adjusted (steps S512, S514).

On the other hand, when the Av electronic dial 17 is rotated by two steps in the same direction, thecontrol proceeds from step S521 to step S522 in which, if the hyper-Av flag is M", the Av dial change flag is reset to permit the mode to be changed to the hyper-ES automatic exposure mode and prevent the diaphragm value Av from being changed, since the hyper-ES automatic exposure mode is not selected Thereafter, the control proceeds to step S524 (steps S521, S522, S523, S524). If the hyper-Av flag is 11119, since the hyper-ES automatic exposure mode is selected, the control proceeds directly to step S524 in which the diaphragm value Av can be adjusted (steps S521, S522, S524).

The Tv, Av dial check sub-routines will be discussed below with reference to steps S511 and S521 in Figs. 45 and 46. In the Tv dial check subroutine, whether or nol 111e Tv - 105 dummy flag is I'V1 is checked at step S551. Since the TV dummy flag is not initially set, the Tv dummy flag is set and the old Tv dial direction flag is replaced with the direction flag, and the control is then S505 (step S552). The second time through if the direction of rotation of the TV 17 is the same as that of the first dial dummy flag is set and the Av dial.

flag is reset, since the present Tv dial direction is identical to the old Tv dial direction flag (steps S555). After that, the control proceeds to step S512.

Conversely, if the direction of the second rotation of the Tv electronic dial 17 is different from thatof the first rotation, the Tv dial dummy flag is reset and the old Tv dial direction flag is replaced with the present dial direction flag, since the old Tv dial direction flag is different f rom the present flag (steps S551, S553, S554). After that, the control proceeds to step S505.

In the AV dial check sub-routine, whether or not the Av dummy flag is 11P1 is checked at step S561. Since the Av dummy flag is not initially set, the Av dummy flag is set and the old Av dial direction flag is replaced wit the present Av dial direction flag, and the control is then returned to step S505 (step S562). The second time through the sub- routine, if the direction of rotation of the Av present Tv dial returned to step the sub-routine, electronic dial rotation, the Tv dummy flag S553, - 106 electronic dial 19 is the same as that of the first rotation, the Av dial dummy flag is set and the Tv dial dummy flag is reset, due to the fact that the present Av dial direction flag is identical to the old Av dial direction flag (steps S563, S565). After that, the control proceeds to step S524.

Conversely, if the direction of the second rotation of the Av electronic dial 19 is different from that of the the first rotation, the Av dial dummy flag is reset and the old Av dial direction flag is replaced with the present since the old Av dial direction flag S563 dial direction flag, is different from the present flag (steps S561 S564). After that, the control proceeds to step S505.

As can be understood from the above discussion, according to the second indication sub-routine, since there is no change i'n the exposure mode, as long as Illeelectronic dial 17 or 19 is not rotated by more Ilian Lwo steps, even if the electronic dial 17 or 19 is rolated accidentally or by mistake, the mode is not changed. In Cin alternative embodiment, it is possible to realize a conLrol system in which mode change does no take place if the-electronic dial 17 or 19 is successively rotated twice within an extremely short space of titne.

- 107 - ill As can be seen from the above discussion, with the present invention, when the hyper-program exposure mode is selected, the shutter speed Tv and the diaphragm value Av can be varied in accordance with the direction of the rotation of the electronic dial 17 or 19, and the mode can be switched to the shutter speed priority automatic exposure mode or the diaphragm priority automatic exposure mode merely by rotating the electronic dial 17 or 19. Furthermore, after the mode is changed to the automatic exposure mode, the shutter speed and the diaphragm value can be adjusted by actuating the electronic dial 17 or 19. Accordingly, if the photographer cannot fully express his or her photographic intention when using the program exposure mode, the photographer may switch the program exposure mode to the automatic exposure mode in which his or her intention can be more easily and freely reflected.

In addition, since the mode can be returned to the initial hyper-program exposure mode when the clear button 23 is turned ON, even after the mode is compulsively switched to the automatic exposure mode, the exposure factor priority automatic exposure mode can be conveniently selected particularly when it is temporarily necessary.

Although the above discussion has been directed to the embodiment in which there are two automatic exposure modes, i.e., the ordinary program exposure mode and the - 108 - hyper-program exposure mode which can be switched to the exposure factor priority automatic exposure mode when the electronic dial 17 or 19 is actuated, it is possible to provide only the hyper-program, exposure mode or more than two program modes.

With the present invention, when a specific program exposure mode is selected, the shutter speed or the diaphragm value can be easily adjusted by the first or second manual setting means in accordance with the photographer's intention without changing the exposure mode.

Furthermore, with the present invention, when a specific program exposure mode is selected, the mode can be switched to the shutter speed priority or diaphragm priority automatic exposure mode by the corresponding first or second between exposure effected exposure In dial 17 mode, the diaphragm the dial diaphragm manual setting means Accordingly, the mode change the program exposure mode and the automatic mode, which is frequently done, particularly in a camera having modes.

the illustrated embodiment, when the electronic or 19 is actuated in the hyper-prograni exposure mode is changed to the shutter speed priority or priority automatic exposure mode, depending on that is rotated. The shutter speed or the value corresponding to the rotated dial is then can be easily many kinds of 1 - 109 manually adjusted. The other one of either the diaphragm value or the shutter speed is then varied in accordance with the object brightness. Consequently, the function in which the shutter speed and the diaphragm value are changed in combination to achieve optimum exposure conditions, similar to the program exposure mode, can be effected.

Furthermore, when the clear button 23 is actuated (turned ON), after the exposure mode is compulsively changed to the hyper-program exposure mode, the mode is easily returned to the program exposure mode. Accordingly, it is convenient for the photographer when he or she wants to temporarily switch to the automatic exposure mode, which gives priority to both of the exposure factors.

If the accuracy of the exposure factors which can be manually set is different from that of the automatically set exposure factors, the shutter speed or the diaphragm value varying in accordance with the rotation of t h ecorresponding electronic dial 17 or 19 can be rounded to be identical to the value of an accuracy which can be manually set. It is also possible to use the exposure factors which are modified to the values greater than or less than those determined by the program exposure mode.

Namely, with the present invention, since one of the exposure factors is retained at the value setin the program exposure mode and the other exposure factor is accordance operation automatically varied in brightness, by a single electronic dial in the program exposure mode, the combination of the shutter speed and the diaphragm value can be easily adjusted in the program exposure mode without switching the exposure mode.

compulsively diaphragm electronic with the object of the associated In the present invention, the exposure mode is changed to either the shutter speed or priority exposure mode when the corresponding dial 17 or 19 is actuated in the hyper-prograrn exposure mode. Thereafter, when the other electronicdial 19 or 17 is actuated, the shutter speed or diaphragm priority exposure mode is compulsively changed back to the diaphragm or shutter speed priority exposure mode.

Therefore, the photographer can easily change the exposure mode without moving his or her eye from the finder.

Furthermore, when the exposure mode is compulsively changed by actuating the electronic dial 17 or 19, the shutter speed or the diaphragm value can be modified by the electronic dial 17 or 19 which has been actuated, resulting in a high level of operability.

Although the above discussion has been directed to mode change among the three specific automatic exposure modes including the program exposure mode, the shutter speed priority automatic exposure mode and the diaphragm - ill - priority automatic exposure mode, the present invention is not limited thereto but can be applied to mode change, for example, between two specific automatic exposure modes, such as the shutter speed priority automatic exposure mode and the diaphragm priority automatic exposure mode. In summary, as the exposure modes can be compulsively changed, the specific exposure modes which are frequently used by the photographer can be selected from among the various exposure modes.

According to an embodiment of the present invention, since the exposure mode can be changed between the two automatic exposure modes in which either the shutter speed or the diaphragm value can be manually set, the mode change between the specific exposure modes is simplified.

In an embodiment of the present invention, when the hyper-program. exposure mode is selected, the mode can be easily changed to the shutter speed priority automatic exposure mode or the diaphragm priority automatic exposure mode by actuating the associated electronic dial 17 or 19. Namely, the mode change between the automatic exposure modes is simplified. In addition to the simplification of the mode change between the automatic exposure modes, the selected automatic exposure mode can be simply returned to the hyper-program mode by actuating the clear button 23.

In particular, in the case that the hyper-program - 112 exposure mode is most frequently used, even if the mode is compulsively and temporarily changed to the shutter speed priority automatic exposure mode or the diaphragm priority automatic exposure mode to take a picture with a shutter speed or diaphragm value which has been deviated from the associated program diagram stored in the memory by actuating the associated electronic dial 17 or 19, the temporarily selected mode can be easily returned to the hyper-program exposure mode by turning the clear button 23 ON. Accordingly, the operability is increased. Furthermore, since the mode is also returned to the hyper- program mode when the main switch 31 is turned OFF or when the taking lens 65 is exchanged, failure to return the exposure mode is avoided.

The requirements needed to return the shutter speed priority or diaphragm priority automatic exposure mode switched away from the hyper-program exposure mode back to the hyper-program exposure mode are not limited to those -mentioned above. For instance, it is possible to return the shutterspeed priority or diaphragm priority automatic exposure mode to the hyperprogram exposure mode when the photometering switch SWS or the release switch SWR is not actuated for a predetermined period of time.

it is also possible to return the diaphragm priority automatic Alternatively, shutter speed priority or - 113 - 1 exposure mode to the hyperprogram exposure mode only when the clear button 23 is turned ON.

With the present invention, if a specific program exposure mode is compulsively switched to another specific program exposure mode, the program mode can be easily returned to the former program mode under a predetermined condition, for example, when the clear switch is turned ON, not only can the mode return be easily effected, but also failure to return the exposure mode after the mode has been temporarily switched is avoided.

With the present invention, the selected mode is indicated in the LCD panel 69 and the indicator unit 71 within the finder in a predetermined manner (Figs.

41, 42 and 43), so that the photographer can visually confirm the selected exposure mode.

For example, when the hyper-program exposure mode is selected, the letter "HY" appears in the LCD panel 69 in addition to the marks, symbols or letters which are indicated in the program exposure mode.

the photographer is alerted to the fact that the mode can be compulsively switched to the EE or ES automatic exposure mode by actuating the electronic dial 17 or 19. Furthermore, when the hyper-program exposure mode is switched to the EE or ES automatic exposure mode by the operation of the Tv or Av electronic dial 17 or 19, the ordinarily Accordingly, 114 photographer can see the set shutter speed Tv and the diaphragm value Av as well as the presently activated mode in the LCD panel 69 and the indicator unit 71, as shown in Figs. 42G and 42H.

When the hyper-manual exposure mode since the letter "HY" appears in the LCD addition to the marks, symbols ordinarily indicated in the photographer can recognize S selected, panel 69 in or letters which are program exposure mode, the at a glance that the optimum shutter speed Tv and diaphragm value Av can be manually adjusted by actuating the clear button 23, as shown in Figs. 41F and 43A.

Furthermore, in the illustrated embodiment, since the three quarter circle and the underlined value appear in the LCD panel 69 and the indicator unit 71, the photographer is alerted that the shutter speed or the diaphragm can be modified by actuating the electronic dial 17 or 19.

In the present invention, since the specific program exposure mode which can be switched to the shutter speed oi diaphragm priority automatic exposure mode by the first and second manual setting means is indicated in the indicating means, the photographer can visually recognize the same. Furthermore, when the mode is compulsively changed to the automatic exposure mode in which the shutter speed and the diaphragm value are manually adjusted, since the selected 91 W 9 - 115 - automatic exposure mode is indicated, the photographer can easily see the variation of the exposure mode and the exposure factors which can be manually adjusted.

In the bodyset shutter speed priority automatic exposure mode or diaphragm priority automatic exposure mode, when the diaphragm value or the shutter speed which is automatically set in accordance with the object brightness reaches the limit, since the automatically set diaphragm value or the shutter speed is fixed at the limit and the manually set shutter speed and the diaphragm value is varied in accordance with the object brightness, the optimum exposure range is expanded. Consequently, little or no readjustment of the shutter speed or diaphragm value requires manual adjustment.

Furthermore, in the shutter speed priority automatic mode or diaphragm priority automatic exposure mode, it is possible to construct the control system in which the upper and lower limits of the shutter speed and the diaphragm value, which can be automatically set, can also be manually set by the photographer.

exposure exposure range can be expanded, and the possibility that a photographer unitentionally sets an incorrect shutter speed or diaphragm value, is reduced. This makes it possible for the photographer to take a picture at a desired shutter speed Consequently, the optimum - 116 exposure with the means f or with the and diaphragm value.

Finally, the exposure control apparatus of the present invention includes an automatic exposure mode in which one of the exposure factors (shutter speed and diaphragm value) can be given priority by effecting the first or second manual setting means while the other factor is automatically adjusted in accordance object brightness, and an exposure factor varying varying one of the exposure factors in accordance object brightness when the other exposure factor is manually set by the first or second manual setting means in the automatic exposure mode, modifying the manually set exposure factor. The control apparatus of the present invention further a means for varying one of the exposure factors in accordance with the object brightness when the other exposure factor reaches an upper or lower limit, whileretaining the other exposure factor at the upper or lower limit. The exposure range which can be manually set is expanded, so that it is not necessary for the photographer to readjust the shutter speed or the diaphragm or to modify the exposure mode.

without exposure includes tl - 117 - t:i b 1 e 1 command name of cominand cotil ent Illifilber of bytes IPU cileck communication check with 1 I PC 1 CPU -11T transfer 1 output all dat.a 1 0 2 CPU -INJ transfer 2 output clata for indication 5 ID 1PU -CPU transfer 1 inpul all data 2 0 4 INJ -CPU transfer 2 input lens data 1 0 11,11 -CPU transfer. 3 inplit, switch (tita 1 1PU -CP11 Lransfer 4 input. exposure mode 1 v 1 - 118 t -:i b 1 e 2 Time G/sec) T v TvT Tv D 8000 1 3 29 1 8 4/8 6000 12. 5 28. 5 is 4000 1 2 28 1 7 4/8 3000 11. 5 27. 5 17 2000 1 1 27 1 6 4/8 1500 10. 5 26. 5 16 1000 1 0 9 6 1 5 4/8 750 9. 5 25. 5 1 5 500 9 25 1 4 4/8 350 8. 5 2-1. 5 1 A 1)50 8 24 1 3 4/8 1 80 7. 5 23. 5 1 3 1 25 7 23 1 2 4/8 6. 5 22. 5 1 6.2 1 1 4/8 5. 5 2 1. 5 1 1 5 2 1 1 0 4/8 4. 5 20. 5 1 0 1 5 4 20 9 4/8 1 0 3. 5 19. 5 9 8 3 1 9 8 4/8 6 2. 5 1 8. 5 8 4 2 1 8 7 4/8 1 7. 5 7 1 1 7 G 4/8 0 7 0. 5 1 6. 5 (3 1 0 1 6 5 4/8 ---5 -0. 5 1 5. 5 5 1). 1 - 1 1 5 4 4/8 3 1. 5 1 4. 5 4 4 -9 1 4 3 4/8 6 -2. 5 1 3. 5 3 8 -3 1 3 2 4/8 10.1 -3. 5 1 2. 5 2 15- -4 1 2 1 4/8 2 0 -4. 5 1 1. 5 1 3 0 -5 1 1 0 4/8 J t 1.

c 1.

- 119 t a b 1 c. 3 0. 5EV AA) augmen- indication FK10. Av M1T AYD talion classifica tion 11 11 15 4/8 38 10. 5 10. 5 15 32 10 10 14 4/8 F11 27 9. 5 9. 5 14 11 3/8 22 9 9 13 4/8 11 2/8 y 19 8. 5 8.5 13 A 11 1/8 16 8 8 12 4/8 11 0/8 F9. 5 13 7. 5 7. 5 12 10 7/8 11 7 7 11 4/8 10 6/8 9. 5 6. 5 6. 5 11 10 5/8 1 8 6 6 10 4/8 10 4/8 F8 6. 7 5. 5 5. 5 10 10 3/8 5.6 5 5 9 4/8 10 2/8 4. 5 4. 5 4. 5 9 10 1/8 4 4 4 8 4/8 10 0/8 F6. 7 3. 5 3. 5 3. 5 8 9 7/8 2.8 3 3 7 4/8 9 6/8 2. 5 2. 5 2. 5 7 9 5/8 2 2 2 6 4/8 9 4/8 F5. 6 1. 7 1 5 1.5 6 9 3/8 1. 4 1 1 5 4/8 1. 2 0. 5 0. 5 5 1 0 0 4 4/8 3 - tab 1 e 4 exposure IPU mode No. CPU mode mode lens ' A' lens ' B' N o.

(4b i t) (3 b i t) (2 b i t) Ill-Ograill 7 llyper Prograni 6 1 4 1)rogram LIMIT 5 1 3 EE- LA 4 ES LA 3 Olyper) Manual LA 2 1 0 Bulli LA 1 9 Ilyper EE - 8 Ilyper ES - 7 6 4 3 I-S 1A 2 Olyper) Manilill LM 1 131111) I.M 0 0 n - 121

Claims (50)

1. CLAIMS:

   if An exposure control apparatus of a camera including a photometering means for detecting the brightness of an object to be taken, an exposure value calculating means for calculating an optimum exposure value in accordance with the object brightness, and an exposure factor setting means for setting a pair of exposure factors having a shutter speed and a diaphragm value, comprising; a manual setting means for manually setting at least one of the exposure factors; a specific program exposure mode in which said pair of exposure factors are automatically set in accordance with the optimum exposure value; and, an exposure factor modifying means for enabling the manual setting means to manually set one of the exposure factors when the manual setting means is actuated in the specific program exposure mode.
2. 2. An exposure control apparatus according to claim wherein, when the" manual setting means sets one of the exposure values, that exposure value is given priority and said exposure factor setting means automatically sets the other exposure factor in accordance with the optimum exposure value and the manually set exposure factor.
3. 3. An exposure control apparatus according to claim 1 or - 122 - 2, wherein said manual setting means comprises first and second manual setting means for independently setting the exposure factors.
4. 4. An exposure control apparatus according to claim 3, wherein said exposure factor modifying means enables one of the manual setting means to set the exposure factor associated therewith when said one of the manual setting means is actuated after the actuation of the other manual setting means, so that the exposure factor associated with the other manual setting means is then automatically set.
5. 5. An exposure control apparatus according to claim 3 or 4, further comprising a means for overriding the actuation of the manual setting means, whereby exposure factors are set by the corresponding manual setting means in the specific program mode, so that the exposure factor is then automatically set by the exposure factor setting means, wherein the means for overriding the actuation of the manual setting means is a clear switch.
6. 6. An exposure control apparatus according to any one of claims 3 to 5, wherein when said first or second manual setting means is actuated in the specific program exposure mode, said exposure factor modifying means sets the associated exposure factor to a value which is identical to the automatically set value.
7. 7. An exposure control apparatus according to claim 11 - 123 6, wherein, when the manual setting means is further actuated, after the initial activation, the associated exposure factor is modified in accordance therewith.
8. 8. An exposure control apparatus according to claim wherein, when a first or second manual setting meansis actuated in the specific program exposure mode, the associated exposure factor, which can be manually set, is set to a value which is identical to the automatically set value, said automatically set value being rounded to have an accuracy which can be manually set.
9. 9. An exposure control apparatus according to claim 3, wherein said first and second manual setting means comprise rotatable electronic dials which can be clicked step by step.
10. An exposure control apparatus according to claim 9, wherein, when the electronic dials are rotated by one step, said exposure factor modifying means enables the associated exposure factors to be manually set.
11. 11. An exposure control apparatus according to claim 9 or 10, wherein, when the electronic dials are rotated by two steps within a predetermined period of time, said exposure factor modifying means enables the associated exposure factors to be manually set.
12. 12. An exposure control apparatus according to claim 10, wherein said exposure factor modifying means modifies and locked 10.

    - 124 the associated exposure factors rotation of the electronic dials.
13. 13. An exposure control apparatus according to claim 2, further comprising a modifying means for modifying the exposure factor having priority, so that when one of the exposure factors is manually set by a first or second manual setting means in the specific automatic exposure mode, the other with the optimum exposure factor, a predetermined factor is fixed exposure factor exposure value.
14. 14. An exposure control apparatus of a camera including a photometering means for detecting the brightness of an object to be taken, and automatic exposure modes in which one of a pair of exposure factors having a shutter speed and a diaphragm value can be manually set while the other exposure factor is automatically adjusted to be set in accordance with the object brightness, comprising; a specific program exposure mode in which said pair of exposure factors are automatically set in accordance with the object brightness; in accordance with the exposure factor is modified in accordanc exposure factor with reference to said one and when the other exposure factor reaches upper or lower limit, the other exposure at the upper or lower limit and said one is modified in accordance with the optimum T - 125 first and second manual setting the exposure factors; an exposure setting means for manually exposure mode selecting means for selecting an mode from among the various possible exposure modes, including, the automatic exposure modes and the specific program exposure mode; and, an exposure mode shifting means for shifting the specific program exposure mode to automatic exposure mode in which the shutter speed or the diaphragm is given priority when the associated first or second manual setting means is actuated.
15. 15. An exposure control apparatus according to claim 14, further comprising an exposure factor modifying means for modifying the associated exposure factor when the first or second manual setting means is actuated after the specific program exposure mode is shifted to the automatic exposure mode, in which the shutter speed or the diaphragm has priority, by the first or second manual setting means.
16. 16. An exposure control apparatus according to claim 15, wherein when the first or second manual setting means is actuated after the mode has been shifted to the automatic exposure mode by the activation of the second or first manual setting means, said exposure mode shifting means compulsively shifts the automatic exposure mode to the first or second automatic exposure mode, respectively.

    compulsively the - 126 -
17. 17. An exposure control apparatus according to claim 15 or 16, further comprising a clear switch, wherein when the clear switch is actuated after the specific program exposure mode is compulsively shifted to the automatic exposure mode, said exposure mode shifting means returns the automatic exposure mode to the program exposure mode.
18. H. An exposure control apparatus according to claim 15, further comprising another program exposure mode, wherein said exposure mode shifting means operates to shift the exposure mode only when the specific program exposure mode is selected.
19. 19. An exposure control apparatus according to any one of claims 14 to 18, wherein said first and second manual setting means comprise rotatable electronic dials which are clicked and locked step by step.
20. 20. An exposure control apparatus according to claim 19, wherein when the electronic dials are rotated by one step, said exposure mode shifting means compulsively shifts the specific program exposure mode to the corresponding automatic exposure mode.
21. 21. An exposure control apparatus according to claim 19, wherein when the electronic dials are rotated by more than one step, said exposure mode shifting means compulsively shifts the specific program exposure mode to the corresponding automatic exposure mode.

    t v i ffi - 127 -
22. 22. An exposure control apparatus according to claim 19, wherein when the specific program exposure mode is compulsively shifted to the corresponding exposure mode, said exposure factor modifying means modifies the corresponding shutter speed or diaphragm value in accordance with the rotation of the associated electronic dial.
23. 23. An exposure control apparatus of a camera, comprising; a photometering means for detecting the brightness of an object to be taken; first and second manual actuating means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value; an automatic exposure mode in which one of the exposure factors can be manually set while the other exposure factor is automatically adjusted to be set in accordance with the object brightness; a specific program exposure mode in which said exposure factors are automatically set in accordance with the object brightness; an exposure mode shifting means for compulsively shifting the specific program exposure mode to the automatic exposure mode, in which the shutter speed or the diaphragm can be manually set, when the associated first or automatic - 128 second manual actuating means is actuated; and, an exposure mode returning means for returning the automatic exposure mode, compulsively selected by the exposure mode shifting means, to the specific program exposure mode.
24. 24. An exposure control apparatus according to claim 23, wherein said exposure mode returning means comprises a clear switch, so that when the clear switch is actuated, said exposure mode returning means operates.
25. 25. An exposure control apparatus according to claim 23 or 24, wherein said exposure mode returning means comprises a lens detecting means for detecting the attachment and detachment of a taking lens to and f rom the camera, so that the exposure mode is returned when the detachment of the taking lens from the camera body is detected by the lens detecting means.
26. 26. An exposure control apparatus according to claim 25, wherein said lens detecting means detects levels of mount pins, provided on the camera body, to detect the attachment and detachment of the taking lens to and from the camera body.
27. 27. An exposure control apparatus according to claim 25 or 26, wherein said lens detecting means detects the attachment and detachment of the taking lens to and from the camera body by data communication with the taking lens X - 129 through mount pins provided on the camera body.
28. 28. An exposure control apparatus according to any one of claims 23 to 27, wherein said exposure mode returning means comprises an auto/manual detecting means f or detecting diaphragm auto or manual modes of the diaphragm of a taking lens, so that when the diaphragm auto mode is detected by the auto/manual detecting means, the exposure mode returning operation is effected.
29. 29. An exposure control apparatus according to any one of claims 23 to 28, further comprising a main switch for controlling power supply to various elements of the camera, wherein, when the main switch is turned OFF, the exposure mode returning operation is effected.
30. 30. An exposure control apparatus of a camera, comprising; a photometering means for detecting the brightness of an object to be taken; first and second manual actuating means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value; an automatic exposure mode in which one of the exposure factors can be manually set while the other exposure factor is automatically adjusted to be set in accordance with the object brightness; a specific program exposure mode in which said - 130 exposure factors are automatically set in accordance with the object brightness; an exposure mode shifting means for compulsively shifting the specific program exposure mode to the automatic exposure mode, in which the shutter speed or the diaphragm can be manually set, when the associated first or second manual actuating means is actuated; and, an indicating means having indicating elements which indicate the selection of the specific program exposure mode and the selection of the automatic exposure mode, which has been compulsively selected by the exposure mode shifting means.
31. 31. An exposure control apparatus according to claim 30. wherein said indicating means comprises an indicating element which indicates that the shutter speed or the the first or is shifted to mode shifting diaphragm value can be manually modified by second manual actuating means when the mode the automatic exposure mode by said exposure means.
32. 32. An exposure control apparatus according to claim 30 or 31, wherein said indicating means comprises indicating elements which indicate the first and second manual actuating means, and wherein, when the automatic exposure mode is selected, only the indicating element corresponding to the exposure factor which can be manually set, is -E - 131 - r 41 indicated.
33. 33. An exposure control apparatus according to claim 31, wherein said indicating means comprises an indicating element which discriminates the exposure factor, which can from the other exposure factor, which is when the automatic exposure mode is be manually set, automatically set selected.
34. 34. An exposure control apparatus according to claim 34, wherein said indicating means displays the shutter speed or diaphragm value which can be manually modified by the first or second manual actuating means, in a flickering manner.
35. 35. An exposure control apparatus according to any one of claims 30 to 34, wherein said indicating means comprises an LCD or LED panel which is provided within a finder.
36. 36. An exposure control apparatus according to any one of claims 30 to 34, wherein said indicating means comprises an LCD panel which is provided outside the camera body.
37. 37. An exposure control apparatus of a camera, comprising; a photometering means for detecting the brightness of an object to be taken; first and second manual setting means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value; an automatic exposure mode in which one of the exposure factors can be manually set while the other exposure factor is automatically set in accordance with the object brightness; specific program exposure mode a exposure factors are automatically set the object brightness; 3 in which said in accordance with an exposure mode shifting means for compulsively shifting the specific program exposure mode to the automatic exposure mode, in which the shutter speed or the diaphragm can be manually set, when the associated first or second manual setting means is actuated; and, an exposure factor holding means for holding one of the exposure factors, which is set at the specific program exposure mode, when the specific program exposure mode is compulsively shifted to the automatic exposure mode by the exposure mode shifting means. -
38. 38. An exposure control apparatus according to claim 37, wherein the exposure factor to be held by the exposure factor holding means is the exposure factor which can be manually set in the compulsively selected automatic exposure mode.
39. 39. An exposure control apparatus according to claim 37 or 38, wherein said exposure factor holding means modifies the exposure factor, which is held thereby, when the first or second manual setting means is actuated after the exposure mode is 1 a.

    - 133 - compulsively shifted to the automatic exposure mode by the first or second manual setting means.
40. 40. An exposure control apparatus according to any one of claims 37 to 39, wherein, when th e program exposure mode is compulsively shifted to the specific automatic exposure mode by the first or second manual setting means, the exposure factor holding means modifies the exposure factor corresponding to the first or second manual setting means to be greater than or less than the value set at the program exposure mode, by a predetermined value, to hold the modified exposure factor.
41. 41. An exposure control apparatus according to any one of claims 37 to 40, wherein said first and second manual setting means comprise electronic dials which vary the shutter speed and the diaphragm value, respectively.
42. 42. An exposure control apparatus of a camera, comprising; a photometering means for detecting the brightness of an object to be taken; first and second manual setting means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value; two automatic exposure modes in which one of the exposure factors can be manually set by the manual setting - 134 means while the other exposure factor is automatically adjusted to be set in accordance with the object brightness; and, an exposure mode shifting means for compulsively shifting the current automatic exposure mode, in which one of the exposure factors can be manually set by the first or second manual setting means, to the other automatic exposure mode, in which the other exposure factor can be manually set, by the other manual setting means when the latter is actuated in the first mentioned automatic exposure mode.
43. 43. An exposure control apparatus of a camera, comprising; a photometering means for detecting the brightnessof an object to be taken; first and second manual setting means for independently setting a pair- of exposure factors having a shutter speed and a diaphragm value; two automatic exposure modes in which one of the exposure factors can be manually set by the manual setting means while the other exposure factor is automatically adjusted to be set in accordance with the object brightness; a specific program exposure mode in which said exposure factors are automatically set in accordance with the object brightness; Z C - 135 - an exposure factor selecting means for selecting one of the exposure modes including the specific program exposure mode and the automatic exposure modes; and, an exposure mode shifting means for compulsively shifting the specific program exposure mode to the automatic exposure mode, in which one of the exposure factors can be manually set, when the associated first or second manual setting means is actuated, and for compulsively shifting the automatic exposure mode to the other automatic exposure mode, in which the other exposure factor can be manually set, when the associated second or first manual. setting means is actuated.
44. 44. An exposure control apparatus of a camera, comprising; a photometering means for detecting the brightnessof an object to be taken; first and second manual setting means for independently setting a pair of exposure factors having a shutter speed and a diaphragm value; an automatic exposure mode, in which one of the exposure factors can be manually set, given priority by the first or second manual setting means, while the other exposure factor is automatically set in accordance with the object brightness; and, a modifying means for modifying an exposure factor - 136 having priority, so that when one of the exposure factors is manually set by the first or second manual setting means at the specific automatic exposure mode, the other exposure factor is modified in accordance with the object brightness while said one exposure factor is fixed at a specific value, and when the other exposure factor reaches a predetermined upper or lower limit, the other exposure factor is fixed at the upper or lower limit and said one exposure factor is modified in accordance with the object brightness.
45. 45. An exposure control apparatus according to claim 44, wherein the upper and lower limits of the shutter speed are defined by a shutter capability range of the camera body.
46. 46. An exposure control apparatus according to claim 44, wherein the upper and lower limits of the diaphragm values are defined by a diaphragm capability range of a taking lens.
47. 47. An exposure control apparatus according to claim 44, further comprising a limit value setting means for setting the upper and lower limits of the shutter speed and the diaphragm value by an external operation.
48. 48. An exposure control apparatus of a camera having a photometering means for detecting the brightness of an object to be taken and an exposure value calculating means Z1 i 01 - 137 for calculating an optimum exposure value in accordance with the object brightness comprising:

    a program exposure mode in which both an shutter speed and an optimum diaphragm value are automatically set by said exposure calculating-means; an automatic exposure mode in which one of said shutter speed or said diaphragm value is automatically set by said exposure calculating means, based on the object brightness and the other of said shutter speed or said diaphragm value selected by a photographer; and means for switching said program mode to said automatic exposure mode, wherein said switching means is also operated to set said desired value after mode switching thereby.
49. 49. An exposure control apparatus according to claim 48, further comprising means for returning -said automatic exposure mode to said program exposure mode.
50. 50. An exposure control apparatus of a camera including a photometering means for detecting the brightness of an object to be taken, an exposure value calculating means for calculating an optimum exposure value in accordance with the object brightness, and an exposure factor setting means for setting a pair of exposure factors having a shutter speed and a diaphragm value, substantially as herein described with reference to the accompanying drawings.

    optimum