JPH059778B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a camera having an automatic focus adjustment device using an optical sensor array, and particularly takes into account that automatic focus adjustment (hereinafter referred to as autofocus) takes time. The present invention relates to a camera equipped with an autofocus device that has been improved to prioritize frame speed and perform high-speed continuous shooting.

Prior Art An autofocus system uses an optical sensor array consisting of multiple optical sensors to measure distance, operates a digital circuit based on this distance measurement information, and automatically drives the photographic lens to the in-focus position. A camera with a dust device has been proposed. Optical sensor arrays in such cameras typically include:
Although CCDs (charge-coupled devices) have been used, the response speed of the photosensor array must be considered in order to obtain a meaningful light distribution pattern. Therefore, the operating time of the photosensor array is usually controlled in accordance with the brightness information from a photoconductive cell (for example, a CdS cell, etc.) provided separately in the camera, taking into consideration the operating characteristics of the photosensor array. There is. In addition, it takes time to process this information in a digital circuit after obtaining distance measurement information, and after pressing the shutter button, the actual shutter release operation (the reference point at which the shutter is released and the film is exposed) is required. There is always a time lag for the autofocus to complete before the following operation is performed. Therefore, when the subject has low brightness, the time it takes to obtain distance measurement information and the time to digitally process the information such as calculations takes nearly an order of magnitude longer than when the subject has high brightness. In other words, what takes several tens of milliseconds at high brightness times takes several hundred milliseconds at low brightness times.

If a long time is spent on autofocus in this way, the shutter release will inevitably be delayed, resulting in a longer frame interval in continuous shooting mode in a motor drive camera. Practically speaking, high-speed continuous shooting was not possible.

Purpose Therefore, the main object of the present invention is to complete the autofocus adjustment operation in the first frame of continuous photographing mode, and also to enable high-speed continuous photographing.

Summary of the Invention Therefore, to summarize this invention, the focus adjustment state of the photographic lens is detected, the photographic lens is displaced to the in-focus position based on the detection result,
an automatic focus adjustment means that outputs a focus adjustment completion signal when the photographing lens reaches the in-focus position; an exposure control means; a shutter release button; and preparation for the next photograph after the operation of the exposure control means is completed. and a preparation means for outputting a ready signal when the preparation is completed; and a preparation means for operating the automatic focus adjustment means and adjusting the focus at the time of the first shooting while the operation state of the shutter release button is maintained. When both the completion signal and the preparation completion signal are output, the operation of the exposure control means is started, and during subsequent shooting, the operation of the automatic focus adjustment means is prohibited and the preparation completion signal is output. and continuous shooting control means for starting the operation of the exposure control means.

Embodiments Hereinafter, embodiments of the present invention shown in the drawings will be described in detail.

1 and 2 are schematic explanatory diagrams showing the mechanical configuration of the main parts of a camera according to an embodiment of the present invention, with FIG. 1 being a front view and FIG. 2 being a longitudinal sectional side view. It is assumed that the camera according to this embodiment is a TTL type single-lens reflex camera as shown in the figure, and is equipped with a motor drive, autofocus, and continuous shooting functions as described later.

In the mechanism of the single-lens reflex camera shown in the figure, 1 is a camera body, 2 is a shutter speed setting member, 3 is a shutter button, 4 is a film rewinding operation member, and 5 is a shooting mode switching member. By rotating, at least () one frame shooting, () auto focus one frame shooting, () continuous shooting,
It is possible to set the following modes: () Continuous shooting with automatic focus priority and () Continuous shooting with frame speed priority.
6 is a pentaprism, 7 is a photoconductor such as CdS
Alternatively, it is a light receiving element made of a photovoltaic element, such as an SPD, and is used to derive luminance information correlated to the light intensity of the subject. 8 is an exchangeable photographic lens, 9 is a translucent or transparent light transmitting part 9 in the center.
10 is the movable mirror 9, which is rotatably provided in the direction of the pentagonal prism 6.
The light transmitting portion 9a is provided at the back of the light transmitting portion 9a.
Mirror box 1 reflects the light passing through a.
This is an auxiliary mirror for guiding the focus detection module 12 through the bottom wall opening 11a of 1. Reference numeral 13 denotes an autofocus drive motor, which drives a distance adjustment gear 8a provided on the photographic lens 8 via a drive gear group 14 to move the photographic lens 8. Reference numeral 15 denotes a mirror and diaphragm drive mechanism, which moves the movable mirror 9 and the auxiliary mirror 10 out of the photographing optical path, moves the diaphragm connecting member 15a, and releases the pressure on the diaphragm interlocking member 8b provided on the photographing lens 8. The aperture interlocking member 8b is driven to a preset position to perform the function of narrowing down the aperture (not shown). 1
Reference numeral 6 denotes a shutter device, which includes a front curtain and a rear curtain (both not shown) that run left and right, and means for locking them.

17 is a spool, 18 is a charging motor provided in the spool 17, which charges the shutter via a coupling mechanism 19;
It supplies driving force for winding the film 21 via the film winding mechanism 20. 22
is a sprocket with a film feeding gear that meshes with the perforation of the film 21, and the amount of feed of the film 21 can be detected based on the amount of rotation of the sprocket 22.

Next, the electrical or electronic circuit configuration that controls the sequence or control for the operation of the above-described mechanical configuration will be explained in relation to the above-described mechanical configuration.

FIG. 3 is a logic circuit diagram of the first embodiment. Hereinafter, the above-mentioned mode switching member 5 will be used as follows: (v) Frame speed priority continuous shooting (iv) Auto focus priority continuous shooting (iii) Continuous shooting (ii) Auto focus 1 frame shooting (i) 1 frame shooting (manual focus) I will set the settings in the order shown and explain each mode.
This invention will be described with a focus on () frame speed priority continuous shooting, which is a feature of this invention, and its configuration and effects. Further, for simplicity, the term "autofocus" will be abbreviated as "AF" below.

As shown in FIG. 3, when the mode switching member 5 is set to frame speed priority continuous shooting, switches S ₁ and S ₁₃ for single-frame continuous shooting are closed, and switches S ₁₂ and S ₁₈ for AF/manual distance measurement are closed. is also closed, and switch _S2 for AF priority/frame speed priority is connected to contact b. When the shutter button 3 is pressed, the switches S ₃ , S ₄ , S ₅ , S ₁₁ are pressed first.
is closed, switch S ₆ is closed, then switch S ₇
is opened from the closed state, and the capacitor _C3 is discharged, giving an AF trigger pulse signal to the flip-flop circuit 51 via the OR circuit 50 (hereinafter, the flip-flop will be abbreviated as FF).
The FF circuit 51 is brought into a set state. A high level signal is output from the Q output of the FF circuit 51 (hereinafter, for simplicity, it will be abbreviated as "H level" or simply "H", and similarly, a low level signal will be abbreviated as "L level" or simply "L"). is derived and provides a start signal to the control circuit 52. The control circuit 52, which operates in synchronization with the clock from the clock circuit 81, receives brightness information or a brightness signal from the photometric circuit 53, and also sends control signals (signals for starting, etc.) to the focus detection light receiving section 54. ), while also supplying control signals and timing signals to a digital arithmetic circuit 56, which will be described later, and summarizing the control operation.
As shown in FIG. 2, for example, the pulse width is determined by the brightness signal from the photometry circuit 53 that processes the brightness information from the light receiving element 7 disposed near the rear surface of the pentagonal prism 6. includes circuit means for determining the length of , and applies a gate signal correlated to the level of brightness to the focus detection light receiving section 54;
A predetermined optimal time interval for accumulating the output charges of the light receiving section is controlled by the gate signal to perform the operation of accumulating the charges output from the light receiving section. Also,
As shown in FIG. 2, the distance measuring circuit 54 is a circuit for receiving and processing brightness distribution information from the focus detection module 12 into which the light reflected by the auxiliary mirror 10 is incident. The focus detection module 12 uses, for example, an optical sensor array having substantially the same function as an autofocus sensor module manufactured by Honeywell, Inc. in the United States.

The output from this focus detection light receiving section is analog/
The signal is digitized by a digital conversion circuit 55, which is known in, for example, Japanese Unexamined Patent Publication No. 54-159259, and is input to a digital arithmetic circuit 56 including a shift register and RAM. The digital calculation circuit 56 calculates the relative positional relationship between the two columns of brightness distribution information regardless of whether the image is in focus or out of focus, and stores the calculation results in a storage means such as RAM. When the storage is completed, a pulsed "H" signal is sent to one input of the AND circuit 57 as a focus detection calculation completion signal. The output of an AND circuit 78 is connected to the other input of the AND circuit 57, and the AND circuit 78 receives an H level signal via a switch _S11 from a circuit 104 which provides an H level as one input. At the same time, the other input is given a signal for giving priority to frame speed, which is a feature of the present invention.

Here, as mentioned above, the mode switching member 5 is set to the position of frame speed priority continuous shooting, but there are two more possibilities for selection in this mode (of course, the setting position for selection is set to the position of the mode switching). needless to say, they are formed in the member 5), the first position and the second position. That is, the switch _S15 is a switch for changing this selection, and in the first position it is connected to the circuit 83 that provides the H level, and in the second position it is connected to the Q output of the FF circuit 58. The meaning of this switching is that the first position allows frame speed priority operation from the first frame of continuous shooting, and the second position allows AF priority operation only for the first frame.

In the explanation of this example, the mode is set to give priority to AF only for the first frame, so the switch S ₁₅ is set to FF.
The FF circuit 58 is connected to the circuit 58 side, and in the initial state, the FF circuit 58 is in a reset state and derives the L level from the Q output. This L level signal is given to the level detection circuit 59 via the switch _S15 ,
The H level is derived as the output of this level detection circuit 59.

This H level is applied to one input of the AND circuit 60, and H is applied to the other input from the circuit 105 which provides an H level via the switch _S8 , so the AND circuit 60 outputs H, and the It is applied to the other input of the AND circuit 78. Since the switch _S11 is closed while the shutter button 3 is pressed, the AND circuit 78 outputs H, and therefore the pulse signal that is the distance measurement calculation completion signal passes through the AND circuit 57.
Enters the set input of the FF circuit 61, and the FF circuit 61
to the set state. An H level signal is derived from the Q output of this FF circuit 61, and the AF drive circuit 6
2, and the AF drive circuit 62 is activated. The output of a comparator circuit 63 is supplied to the AF drive circuit 62, and the drive amount is controlled based on the output value of the comparator circuit 63. That is, one input to the comparison circuit 63 is stored information as out-of-focus information from the digital arithmetic circuit 56, and the other input is information related to the amount of movement of the photographing lens 8 from the lens distance movement amount detection circuit 64. information is input, compared and processed, and a signal based on the difference is output to the AF drive circuit 62, and the AF drive circuit 62 drives the AF drive motor 1 according to this signal.
A driving means such as No. 3 is activated to drive the photographing lens 8. When both pieces of information input to the comparison circuit 63 are balanced, the AF drive circuit 62 outputs a focusing pulse signal. This focusing pulse signal is applied to the reset input of the FF circuit 61 through the OR circuit 65 and disables the AF drive circuit 62. That is, while the AF drive circuit 62 is activated, the drive circuit 62 drives the AF drive motor 13 and controls the distance adjustment gear 8a provided on the photographing lens 8 via the gear group 14. The driving circuit 6 moves the lens 8 until it is automatically focused at the required position.
2 is immediately deactivated and outputs a focusing pulse signal indicating that AF adjustment is complete.

This focusing pulse signal is further transmitted to an AND circuit 66
It serves as an initial trigger pulse for starting the release circuit 71 to be operated next. In other words, switch S ₅ is shutter button 3.
is closed while being pressed, so H continues to be derived from the circuit 106 that provides the H level, so the focusing pulse passes through the AND circuit 66, further passes through the OR circuit 67, and is output to the FF circuit. 68, the FF circuit 68 is set to the set state,
Deriving the H level from the Q output, AND circuit 6
Give it to one input of 9. The other input of the AND circuit 69 derives an H output when the charge is completed.
The Q output of the FF circuit 70 is connected. That is, the FF circuit 70 is reset by the charge completion signal from the charge completion detection circuit 72, and the Q output is changed to H.
The H signal is derived from one input from the FF circuit 68 as described above, and the AND circuit 69
An H signal is output from the camera, the release circuit 71 is activated, and the photographing operation is started. That is, the mirror 9 and the auxiliary mirror 10 are retracted out of the photographing optical path by the mirror/diaphragm drive mechanism 15, and the aperture coupling member 15a is moved to release the pressure on the aperture interlocking member 8b provided on the interchangeable lens 8, thereby interlocking the aperture. The member 8b is driven to a preset position to narrow down the diaphragm, and then the front curtain of the shutter device 16 is unlocked to start exposing the film, and the exposure is ended when the rear curtain completes travel. Then, near the end of the trailing shutter curtain, switch _S9 changes from closed to open, generates a pulse of positive polarity, and switches the FF
The circuit 70 is set, the Q output is lowered to L, and the Q output is set to H to start the charge drive circuit 73. This start signal drives the charging motor 18 provided in the spool 17, charges the shutter via the coupling mechanism 19, and winds up the film via the film winding mechanism 20. The coupling mechanism 19 also returns the mirror to the photographing optical path and charges the force for retracting the mirror from the photographing optical path, moves the diaphragm to the fully open position and charges the diaphragm force. On the other hand, this pulse signal is passed through the OR circuit 76 to other FFs.
Reset the circuits 51, 58, 61, and 68 (however, the FF circuit 58 is in the reset state for the first frame,
The FF circuit 61 is already in the reset state by the focus signal), and is forced into the initial state or standby state. The charge drive circuit 73 is independent of whether the shutter button 3 is pressed or released, and is activated by the shutter close completion signal (pulse signal of the switch _S9 ).

The completion of the charge operation is determined by detecting the amount of film feed by detecting the amount of rotation of the sprocket 21, and by causing the charge detection circuit 72 to detect the completion of charging of the mirror/aperture by the coupling mechanism 19. circuit 7
This is accomplished by deriving the H output to 0, resetting the FF circuit 70, and disabling the charge drive circuit 73. As described above, the first frame in the continuous mode is photographed, but from the second frame onward, the operation or control proceeds as follows.

The trigger signal for the AF operation in the shooting of the second frame and subsequent frames is a signal based on the up and down of the movable mirror 9. That is, the switch _S10 is changed from open to closed at the beginning of the operation of retracting the movable mirror 9 out of the photographing optical path (hereinafter referred to as mirror up), and is changed from closed to open near the end of the mirror down to charge the capacitor _C1 . Switch the positive polarity pulse based on S ₁ ,
It passes through the OR circuit 50 and is applied to the set input of the FF circuit 51 through the switches S ₁₂ and S ₄ which remain closed, thereby setting the FF circuit 51 in the set state again. A start signal is input from the Q output to the control circuit 52, and the aforementioned circuit group including the distance measuring circuit 54 starts the distance measuring operation. On the other hand, capacitor
The pulse signal based on the charging of _C1 sets the FF circuit 58 via the switch _S3 , which is closed by pressing the shutter button, and derives the H level from the Q output. 5
Activate 9. In this way, the level detection circuit 59
By activating
It is possible to start a selection operation of whether to perform AF distance adjustment or to take a photograph at the photographing distance position used in the previous photograph. That is, when the luminance (relatively high luminance) corresponds to a time necessary and sufficient for the distance measuring operation in the distance measuring circuit 54 to be shorter than a predetermined value, the level detection circuit 59 outputs an H level signal. Then, one input of the AND circuit 57 is always kept open (at H level) to complete the AF adjustment operation. On the other hand, when the luminance is such that the necessary and sufficient time for distance measuring operation is longer than the predetermined value (relatively low luminance), the level detection circuit 59 outputs an L level signal. One input of the AND circuit 57 is always closed (set to L level),
Even if the AF adjustment operation is performed, the distance measurement completion signal from the digital calculation circuit 56, that is, the memory completion signal is prevented from passing through the AND circuit 57,
The AF drive circuit 62 is not activated. Therefore, the focus position of the photographing lens 8 continues to be adjusted to the distance at the time of the previous photograph. On the other hand, regarding the shutter release, an H level signal inverted by the inverter 74 based on the L output from the level detection circuit 59 is input to the third input of the AND circuit 75, and when the shutter button is pressed, the switch _S5 is activated. Since the switch S10 is closed and the movable mirror 9 goes down, the switch _S10 is open and H is input from the inverter 80 to the second input of the AND circuit 75, so the AND circuit 75 outputs H. However, since the FF circuit 68 is set and H is applied to one input of the AND circuit 69, the release circuit 71 can be activated immediately upon completion of charging. Therefore, if the brightness becomes low during "continuous shooting", AF adjustment is not performed, and continuous shooting can be continued with the focal length adjusted just before, allowing frame speed priority continuous shooting to be performed. It is something. Furthermore, by switching the switch S ₁₅ , in the second position (when connected to the FF circuit 58), AF adjustment is always activated for the first frame of continuous shooting regardless of the brightness information, and in the first position (when the switch S ₁₅ is set to H) When connected to the output circuit 83), it is possible to control whether or not to activate AF according to the luminance information from the first frame during frame speed priority continuous shooting.

When you release shutter button 3, switch S ₇
is closed, and then switches S ₃ , S ₄ , S ₅ , and S ₁₁ are opened, and switch S ₆ is changed from closed to open, and a positive pulse is generated by charging the capacitor C ₂ connected to switch S ₆ . is generated and the FF is passed through the OR circuit 76.
While resetting the circuits 51, 58, 68,
The pulse is also supplied to the FF circuit 61 via the OR circuit 65, and when the FF circuit 61 is in the set state, it is forced into the reset state and everything is brought into the initial state.

In the first embodiment shown in FIG. 3, a display circuit 77 is provided to which the output of the photometric circuit 53 is input. This display circuit 77 is connected to the photometry circuit 53.
It receives the output voltage or current from the shutter button and displays the time lag in seconds until the shutter operates (exposure) after pressing the shutter button, displays the seconds required for AF operation, and displays warnings.For example, this time, the previous AF
This is a circuit for notifying that a photograph will be taken at a predetermined focal length. Of course, the display circuit 77
It goes without saying that the display element includes display elements such as well-known display segments, light emitting diodes, liquid crystals, etc., and that the display elements are disposed at appropriate positions within the viewfinder, for example.

Next, the operation when the mode switching member 5 is set to another mode will be described.

(iv) In AF priority continuous shooting mode, switch S ₁ ,
S ₈ , S ₁₂ , S ₁₃ are closed, switch S ₂ is at contact a,
The switch _S15 is connected to the FF circuit 58 side. A circuit 79 that provides an H level is connected to contact a. In the initial state, the FF circuit 58 is in a reset state, L is input to the level detection circuit 59, and H is normally output from the level detection circuit 59, and it has a function that is activated when the FF circuit 58 is set. The level detection circuit 59 is
Derive H output by H input from contact a,
That is, in the AF priority continuous shooting mode, the FF circuit 59 always outputs H.
Therefore, inverter 74 always outputs L, and AND circuit 75 is always kept deenergized. Therefore, in this shooting mode, the FF circuit 68 is set by the AF adjustment completion signal that always passes through the AND circuit 66 regardless of the brightness.
The release circuit 71 is started by the H output of the FF circuit 70 when the charge is completed, and the photographing operation is started, and after the photographing is completed, the next photographing is performed by the next AF adjustment and the completion of the charge operation.

(iii) In manual focus adjustment continuous shooting mode that does not involve AF adjustment, switches S ₁ and S ₁₃ are closed,
Switches S ₈ and S ₁₂ are open, switch S ₂ is connected to contact a, and switch S ₁₅ is connected to FF circuit 58.
connected to the side. Since the switch _S8 is open, the AND circuit 60 always outputs L, and the AF drive circuit 6
Since switch S ₁₂ is open, no start signal is issued to the circuit group including distance measuring circuit 54. AND circuit 7
Since the second and third inputs of S5 are H, when the switch _S5 is closed by pressing the shutter button 3, the AND circuit outputs an H signal and sets the FF circuit 68, and since charging has already been completed, the release is not completed. The circuit 71 is activated and performs the photographing operation as in the previous mode. From the next photograph, the FF circuit 68 is set again by the mirror down signal of the movable mirror 9 (by opening/closing the switch _S10 ), and the release circuit 71 is activated by the charge completion signal to perform continuous photographing.

(ii) AF adjustment - During frame photography, switches S ₁ and S ₁₃ are open, switches S ₈ and S ₁₂ are closed, and switch S ₂ is connected to contact a. Since switches S ₁ and S ₁₃ are open, the capacitor C ₁ when the movable mirror 9 returns to the photographing optical path (when the mirror is down)
A pulse signal based on the charging of the OR circuit 50,
Only the pulse signal generated by opening the switch _S7 when the shutter button 3 is pressed is input to the OR circuit 50 without being input to the inverter 80. AF adjustment and shooting are performed only once when the shutter button 3 is pressed. On the other hand, since the AND circuit 60 always outputs H, the output of the AND circuit 75 remains L, and the AF
H output from AND circuit 66 upon completion of adjustment.
The FF circuit 68 is set and the shooting of the first frame is completed.
After FF circuit 68 is reset, FF circuit 51 is not reset. Therefore, even if the Q output of the FF circuit 70 becomes H upon completion of charging, the output of the AND circuit 69 remains L and the release circuit 71 does not operate again, resulting in only one frame being photographed.

(i) In single-frame shooting with manual focus adjustment, where AF is not continuous, switches S ₁ , S ₈ , S ₁₂ , and S ₁₃ are open, and switch S ₁₅ is connected to the FF circuit 58 side.
Switch _S2 is connected to contact a. switch
Since S ₁₂ is open, there is no AF-related operation, and when the shutter button is pressed, the switch S ₅ changes from L to H due to opening and closing, and the AND circuit 75 outputs an H signal, causing the release circuit 71 to be activated.
After the first operation, switch _S13 is open, so FF circuit 6
8 remains reset and continuous shooting is prevented. It is clear that the lens is not moved carelessly during frame speed priority shooting at low brightness in the frame speed priority shooting mode. That is,
The output from the photometry circuit 53 to the level detection circuit 59 is output from the digital calculation circuit 5 because a low luminance signal is outputted by the movable mirror 9 retraction operation drive member regardless of whether the movable mirror 9 is retracted or not.
Even if the arithmetic memory completion pulse signal is output from 6, the second input of the AND circuit 57 remains L.
This is because the FF circuit 61 is not set.

In addition, in the first embodiment shown in FIG.
A contact C is provided as a third contact at _S2 , and the contact C is connected to a circuit 103 that provides an L level. The role of the contact point C is to always perform AF adjustment for the first frame only, and to prevent any AF adjustment operation, that is, the operation of the AF drive circuit 62, in subsequent continuous shooting. Regarding specific operations, the initial settings and the switch operation by pressing the shutter button are as follows: Switch S ₂
The process is the same as for frame speed priority continuous shooting except for the connection. In the first frame, since the Q output of the FF circuit 58 is L, the level detection circuit 59 is in an inactive state, so H is derived from the level detection circuit 59 and the memory completion signal pulse from the digital arithmetic circuit 56 is sent to the FF circuit. 61 is allowed, and AF operation is performed. However, from the second piece onwards,
Since H is output from the Q output of the FF circuit 58, the level detection circuit 59 is activated and derives an output according to the input from the switch _S2 . That is, since the L level signal is continuously output, the AND circuit 7
8, an L level signal is output, and the memory completion signal is blocked in the AND circuit 57.
The AF drive circuit 62 is not activated at all.
Therefore, the second and subsequent frames are photographed with the focus position of the first frame unchanged.

Next, a second embodiment shown in FIG. 4 will be described.
In the logic circuit diagram shown in FIG. 4, the same reference numerals as those in the first embodiment indicate the same or corresponding parts, and the second embodiment will mainly be described with parts corresponding to the differences.

Regarding the display circuit for displaying necessary information or warning the photographer, in the second embodiment, the output from the photometry circuit is used as one input of the comparison circuit 96, and the other input is a variable resistor _R1 . Provide a divided voltage with fixed resistor R ₂ , and this 2
Based on the two comparisons, the light emission/extinction of the light emitting diode connected to the output section of the comparison circuit 96 is controlled. The variable resistor _R1 is a resistor that is provided so that it can be changed arbitrarily according to the photographer's desire, or can be changed in conjunction with the set frame speed during continuous shooting. The reason why the variable resistor _R1 is made variable is to preset an allowable range for determining whether or not the time required for AF adjustment allows the required frame speed to be obtained without missing the shutter speed. When shooting conditions deviate from this range, a warning will be displayed and a warning will also be displayed indicating that the shooting is being performed at the focus position of the previous AF adjustment, automatically providing the necessary information to the photographer. This is used as a guideline for determining whether or not to carry out the work. In this way, especially in low-light conditions, the time lag between pressing the shutter button for AF adjustment and the shutter release will be longer than necessary, and the frame interval during continuous shooting will become abnormally long, making it difficult to maintain perfect shutter accuracy. This has the advantage of eliminating the inconvenience of missing or not being able to obtain the required piece speed.

Regarding the circuit group that starts the shutter release,
The second embodiment has a circuit configuration that shortens the time lag during AF adjustment operation compared to the first embodiment. That is, the memory completion signal from the digital arithmetic circuit 56 is introduced into one input of the AND circuit ₁₀₁ , the other input of which is connected to the H level circuit 104 via the switch S11, while the output from the AND circuit 101 is ORed. It is introduced into the set input of the FF circuit 92 via the circuit 91. This FF circuit 92 is
As a preparatory operation for moving the movable mirror and diaphragm at the observation position to the photographing position, an FF for giving a signal to energize the locking release circuit 93 for releasing the locking of the movable mirror and diaphragm at the observation position.
It is a circuit. A movement completion detection circuit 94 detects that the movable mirror and the diaphragm have moved to the photographing position.
is connected to the input of The first input of the AND circuit 69 is connected to the Q output of the FF circuit 68, which can be set by the pulse input from the OR circuit 67, while the second input receives the charge completion signal described above (first embodiment). A winding completion signal based on the detection of the completion of film winding, which is substantially the same as the above, is input. With such a circuit configuration, the AND circuit 66 and the OR circuit 6 in the first embodiment
5 is no longer necessary. In addition, the output section of the switch _S9 that generates a pulse signal when the shutter is closed and the
It is connected to the reset input of the FF circuit 92.
According to such a circuit configuration, when the AF drive circuit 62 is operated based on the distance measurement information memory completion signal to perform focus adjustment, the movable mirror and the diaphragm can be moved to the photographing position almost at the same time.
Then, a winding completion signal, a movable mirror and aperture photographing position movement completion detection signal (from circuit 94) and
The shutter starting circuit 90 is activated by AND processing (circuit 69) of the AF adjustment completion signal to open the shutter. Therefore, as shown in the first embodiment, automatic distance measurement is performed after pressing the shutter button,
Compare this to a sequence in which the lens is moved to perform focus adjustment after memorizing distance measurement information, and the movable mirror and diaphragm are moved to the shooting position only after the adjustment is completed, and the shutter cannot be opened until this movement is complete. It is obvious that the time lag can be shortened by doing so, and thereby the inconvenience of the frame speed being delayed during continuous shooting can be improved without losing the exquisite shot position.

Note that in the first embodiment, if the shutter button 3 is released while the AF drive circuit 62 is operating, the AF adjustment operation is stopped by the output of the OR circuit 76, and the release operation cannot be performed. Since the movable mirror and the aperture system are moved to the photographing position in response to the distance measurement completion signal, if the shutter button 3 is released before the distance measurement completion signal is output,
Switch _S11 opens and AND circuit 101 output becomes L, movable mirror and aperture system are not driven and AF
Since no adjustments are made, the photographing operation is aborted. However, when the shutter button is released after the completion signal is output, a reset pulse is generated via the OR circuit 76.
Since it is not input to the FF circuit 61,
It should also be noted that the photographing operations other than the charge operation are not canceled until after the next photograph is taken.

Next, the timer circuit T of the second embodiment and a group of circuits correlated thereto will be explained. A resistor R ₂ and a capacitor C ₆ are connected in series between the power supply and the ground, and a switch S ₁₄ is provided between the resistor R ₂ and the capacitor C ₆ and the ground, and an emitter is connected at the connection point. It is connected to a PNP transistor Tr whose base is connected to a switch _S15 via a resistor, and is further connected to a switching circuit 95 which detects that a predetermined voltage level has been reached and derives an L level signal. . Also, the difference from the first embodiment is that the inverter 74 and the third
A delay circuit 100 is interposed between the input and the AF drive circuit 62 to provide a delay time approximately equal to the previously known maximum time required for focus adjustment by the AF drive circuit 62. was simply an H level deriving circuit, but in this example,
A control H that is configured to give H only by the set output (AF start signal) from the FF circuit 51.
This is an output circuit 83'. In addition,
As shown in the figure, the resistor _R2 is a variable resistor, so the setting time of the timer circuit T is variable.
Further, it is configured to be variable in conjunction with the adjustment operation of the variable resistor _R1 described above. Also, switch
_S14 is for switching settings that prioritize frame speed when open and prioritize AF when closed. The main purpose of incorporating such a timer circuit is to
The purpose is to release the shutter regardless of the AF operation and give priority to frame speed over AF.
The operation will be explained below.

The setting mode is continuous frame speed priority, and the switch
_S14 is open and switch _S15 is on the FF circuit 58 side (second
position). FF for the first frame of continuous shooting
Since the Q output of the circuit 58 is L, the transistor
The Tr is conductive, the timer circuit T does not operate, and the switching circuit 95 outputs H, completing the AF operation. At the end of the first frame, the FF circuit 58 is set,
Outputs H to Q output. The transistor Tr becomes non-conductive and the capacitor C ₆ starts charging. If the brightness is low (the light emitting diode 97 is lit as a warning), the derivation of the memory completion signal from the digital arithmetic circuit 56 is delayed, so the timer circuit After the time t ₀ set by T, the output of the switching circuit 95 is inverted to L, and the passage of the memory completion pulse signal from the AND circuit 57 is blocked, and the AF drive circuit 62
On the other hand, the inverted output
4. The signal reaches the AND circuit 75 via the delay circuit 100, and the H output from the AND circuit 75 sets the FF circuit 68, and the FF circuit 92 via the OR circuit 91. As a result, the lock release circuit 93 is activated, the movable mirror and the aperture move to the photographing position, and the completion signal from the movement completion detection circuit 94, the winding completion signal, and the set output of the FF circuit 68 all become H. Then, the shutter starting circuit 90 is activated. That is, the timer circuit T gives priority to the frame speed. Of course, in the case of high brightness,
It goes without saying that the AF adjustment operation is performed because the memory completion signal enters the AND circuit 57 earlier than the set time _t0 .

Next, when the switch _S15 is connected to the control H output circuit 83' (first position), the FF circuit 51 is set by the AF trigger signal caused by the opening of the switch _S7 , and this start signal sets the FF circuit 51. Then, the H output circuit 83' outputs an H level. Therefore, the transistor Tr is turned off, and the timer circuit T is activated from the first frame of continuous shooting, allowing frame speed priority shooting.

In this second embodiment, the mode switching member 5 (see FIG. 1) is provided with a first position and a second position even in the AF-frame photographing mode. That is, in the first position, switch _S14 is open, switch _S15 is connected to control H output circuit 83', and operates timer circuit T. In the second position, the switch
_S14 is closed so that the shutter cannot be released unless the AF adjustment operation is completed. In this way, there is an advantage that the time lag of the first frame can be prioritized so that delicate shutter movements are not missed, and a mode suitable for the subject can be arbitrarily selected according to the photographer's preference.

In addition, although the above two embodiments have been listed, since they both use a motor drive system, continuous shooting can be done at a fairly high speed, but when linked with an AF device, there is a limit, so the frame speed is limited as described above. This is to achieve high-speed shooting by _giving priority to
Starts charging operations such as film winding, and sends a signal (switch) indicating that the movable mirror has returned to the observation position.
It is also worth noting that _S10 ) is used as the AF trigger.

Effects As detailed above, according to the present invention, in continuous shooting, AF is performed for the first frame, and for subsequent frames, the AF adjustment operation is not performed anew and is determined based on the previous frame. Photographing is performed at a lens position that is higher than that of the camera, and priority is given to the frame speed in the continuous photographing mode, so that high-speed continuous photographing is possible.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the mechanical configuration of the main parts of a camera according to an embodiment of the present invention, FIG. 2 is a vertical side view thereof, FIG. 3 is a logic circuit diagram of the first embodiment, and FIG. 4 is a logic circuit diagram of a second embodiment. 5... Mode switching member, 7... Light receiving element, 8...
... Photographing lens, 12 ... Optical sensor array, 13
...AF drive motor, 16...shutter device,
18...Charging motor, 20...Film winding mechanism, 53...Photometry circuit, 54...Distance measurement circuit,
56... Digital calculation circuit, 57, 69... AND circuit, 59... Level detection circuit, 58, 6
8, 70...Flip-flop circuit, 62...Auto focus drive circuit, _S1 to _S15 ...Switch, T...
...Timer circuit.

Claims (1)

[Claims] 1. An automatic system that detects the focus adjustment state of the photographic lens, moves the photographic lens to the in-focus position based on the detection result, and outputs a focus adjustment completion signal when the photographic lens reaches the in-focus position. a focus adjustment means; an exposure control means; a shutter release button; a preparation means for making preparations for the next shooting after the operation of the exposure control means is completed, and outputting a ready signal when the preparation is completed; While the operating state of the shutter release button is maintained, the automatic focus adjustment means is operated during the first shooting, and when both the focus adjustment completion signal and the preparation completion signal are output, the exposure control is performed. continuous shooting control means that starts the operation of the automatic focus adjustment means during subsequent shooting, and starts the operation of the exposure control means when the preparation completion signal is output. A camera with an automatic focus adjustment device.