JPH081506B2 - Focus adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a focus adjusting device for switching between auto focus and manual focus.

<Prior Art> Conventionally, a camera capable of switching between autofocus and manual focus has been known. In the conventional device, a selector such as an automatic / manual switching dial is provided, and when the selector is set on the auto side, the manual focus cannot be executed unless the selector is set on the manual side. Was there.

Therefore, if you want to slightly shift the focus with manual focus after focusing with auto focus, you need to set the selector to manual and then perform manual operation, which results in poor operability. It was.

Also, as a solution to this problem, a camera that immediately shifts from autofocus to manual focus operation by pressing the manual operation button is also available, for example, in the actual open sho 58-1526.
It is known from Japanese Patent No. However, in the technique according to the publication, even if the lens is determined to be out of focus by the autofocus operation and the lens is moving in the focus direction, the lens is driven by the manual focus when the button is pressed. . Therefore, regardless of the photographer's will, if the button is accidentally pressed down, the photographer thinks that autofocus is in focus, but it does not stop. There is no possibility of being out of focus, and the operator may erroneously determine that autofocus is impossible.

<Purpose> In view of the above matters, the present invention provides an autofocus mode in which an imaging lens driving circuit drives an imaging lens to perform a focusing operation based on a focus signal detected by a focus state detection circuit, In a focus adjusting device having a manual focus mode in which the imaging lens drive circuit is operated by an operation signal formed by operating a manual operation member to perform focusing by the imaging lens, a focus state is detected by the focus state detection circuit. When the out-of-focus state is detected and the focusing operation based on the focus signal is being performed, the response of the imaging lens drive circuit to the operation of the manual operation member is prohibited, and the focusing based on the operation signal is performed. In addition, the focus state detection circuit detects the in-focus state as the focus state. When it is known, the response of the imaging lens drive circuit to the operation of the manual operation member is permitted, and the operation of the imaging lens drive circuit is operated by the operation of the manual operation member to operate based on the operation signal. By providing a mode switching circuit that drives the image lens, even if the manual operating member is accidentally brought into the operating state before focusing by autofocus, it is possible to prevent focusing by manual focusing. (EN) A camera with improved operability by allowing manual focus only by operating a manual focus member after focusing.

<Embodiment> FIG. 1 is an external view showing the external appearance of a camera adopting the lens driving device according to the present invention. In the figure, 1 is a camera body, 2 is a lens barrel to be mounted on a mount portion of the camera body 1, 3 is a release button, 4 is a zoom operation member, which is arranged at a position where it is easy to operate when holding the camera, and is usually at a neutral position. If there is, move to the arrow 5 side and tele side, arrow 6
You can zoom to the wide side by moving it to the side. FIG. 2 is a sectional view showing the internal structure of the camera body and lens barrel shown in FIG. In the figure, 1 is the camera body shown in FIG.
Reference numeral 2 indicates a lens barrel. G1 is a focus lens group and is held in the lens barrel 7. The lens barrel 7 has a rack portion 7a. M1 is a focus motor, and a worm gear 8 is arranged at an output end thereof and meshes with the rack portion 7a. G2 is a zoom system lens group which is held in the lens barrel 9, and the lens barrel 9 also has a rack portion 9a. M2 is a zoom drive motor with a worm gear 10 at the output end.
It engages with the rack portion 9a. G3 is a relay lens. Reference numeral 11 denotes a main mirror, which is a half mirror at the center thereof, and guides the light entering through the taking lenses G1, G2, and G3 via the sub-mirror 12 to the autofocus circuit AF. Reference numeral 13 is a pentaprism, which also guides light to a photometric circuit LM arranged near the eyepiece.

FIG. 3 shows a drive circuit arranged in the camera body for driving the lens barrel shown in FIGS. In FIG. 3, SW1 is a switch interlocked with the first stroke operation of the release button 3 shown in FIG. The switch SW1 is composed of a touch switch that is turned on when the release button is touched. SW2 is a switch interlocking with the operation member 4 shown in FIG. 1, and when it is moved to the arrow 5 side in FIG. 1, it is connected to the contact A and when it is moved to the arrow 6 side it is connected to the contact C and connected to the neutral point B.
Connected to. E is a power supply. R1 to R3 are protection resistors and R4 to R15 are base resistors of the transistors. A
The F circuit AF is connected to the power supply E via the switching transistor Tr1.
It is connected to the. The photometric circuit LM is connected to the power supply via the switching transistor Tr10. In the AF circuit AF, D is an infinite side output terminal, E is a close-up side output terminal, F is a focusing output terminal, and G is a distance measurement impossible output terminal. FF is a flip-flop, the set terminal S is connected to the output terminal of the OR gate OR3, the reset terminal R is connected to the switch SW1, and the output Q is the AND gate A via the inverter IN1.
It is input to N2 and AN3, and further connected to the base of the transistor Tr12 via a resistor R15. Q output is a direct resistance R
It is connected to the base of the transistor Tr11 via 14 and inputted to the AND gates AN8 and AN9. AN1 is an AND gate to which the A terminal and B terminal of the switch SW2 are input, and the output is input to AND gates AN2 and AN3. The output of the AND gate AN1 and the Q output of the flip-flop FF are input to the AND gate AN2 via the inverter IN1, and the D output of the AF circuit is also input.
Similarly, AND gate AN3 output and AF of AND gate AN1
The E output of the circuit AF and the Q output of the flip-flop FF are input via the inverter IN1. Similarly AND Gate A
The output of the AND gate AN1, the E output of the AF circuit AF and the Q output of the flip-flop FF are also input to N3 via the inverter IN1. AN4 is an AND gate, and the A terminal of the switch SW2 is input via the inverter IN2 and the switch SW1 is input via the inverter IN3, and the output is AND gate AN8.
Is input to OR gate OR1 has AND gate AN8
And the output of the AND gate AN2 are input, and the output is the transistor Tr2, through the inverter IN8 and the resistors R5, R6.
Input to the base of Tr3. AN5 is an AND gate and is connected to the C terminal of the switch SW2 and the switch SW via the inverter IN4.
1 is input and the output is input to AND gate AN9. The output of the AND gate AN9 and the output of the AND gate AN3 are input to the OR gate OR2, and the output is connected to the bases of the transistors Tr4 and Tr5 via the inverter IN9 and the resistors R7 and R8. AN6 is an AND gate to which the A terminal of the switch SW2 and SW1 are input via the inverter IN6, and the output is connected to the bases of the transistors Tr6 and Tr7 via the inverter IN10 and the resistors R9 and R10. AN7 is an AND gate and the switch SW2 is connected through the inverter IN7.
C1 terminal and SW1 are input and the output is inverter IN11
And resistors R11 and R12, and are connected to the bases of the transistors Tr8 and Tr9. M1 is the focus drive motor shown in the second illustration, and M2 is the zoom drive motor shown in the second.

D1 to D4 are brake diodes. H is a low voltage circuit that can obtain a voltage lower than that of the power source E.

Next, the operation of the present invention having the above configuration will be described. In the above configuration, the first release button 3 shown in FIG.
When stroke operation is performed, SW1 in Fig. 3 is closed. As a result, the base potential of Tr1 goes down and transistor Tr1 turns on.
The AF circuit operates. Similarly, the transistor Tr10 is turned on and the photometric circuit LM operates. A part of the light passing through the lens is guided to the AF circuit as shown in FIG. 2, and a high level is sent out from the D output terminal when moving to the infinity side by a known calculation output, and an E output when moving to the close side. High level is sent from the terminal. When focusing, the D and E output terminals are at low level and the F output terminal is at high level. The G output terminal outputs a high level when the distance cannot be measured, for example, in the case of a dark system or a low contrast in the case of the active system and in the case of a distant object in the active system. Further, if the focus is not achieved even after the time until the normal focus is passed, the output may be transmitted. Now, when the calculation result of the AF circuit is moved to the infinite side, the D output terminal becomes high level and is input to the AND gate AN2. Since the zoom operation switch 4 is not operated, SW2 is at the neutral point B and the AND gate AN1 is at the high level input, so the output is also at the high level and the high level is input to the AND gate AN2. Also, the flip-flop FF is not set until a high level is sent from the output terminals F and G of the AF circuit, so a low level is sent from the Q output and the inverter IN1
High level is input to the AND gate AN2 via.
As a result, the AND gate AN2 outputs a high level output and the OR gate OR1 receives a high level input, so that the output of the OR gate OR1 becomes a high level output. At this time, since the Q output of the flip-flop FF is low, the transistor Tr11 is turned on and the E power is supplied to the motor circuit, so that the high output of the OR gate OR1 turns on the transistor Tr3. At this time, since the low level from the E output terminal of the AF circuit is input to the AND gate AN3, the output of AN3 becomes low level and is input to the OR gate OR2. Also, since SW1 is closed at one input end of the AND gate AN5, there is a high level input via the inverter IN5, but since the switch SW2 is in the neutral position, a low level is input to the other input end via the inverter IN4. Therefore, the output becomes low level and is input to the OR gate OR2, and the OR gate OR2 also outputs the low level output. Therefore, the transistor Tr5 is turned on.
Due to the above, current flows from power supply E → Tr3 → M1 → Tr5 and motor M1
Rotates normally, and the lens barrel 7 is pulled in by the worm gear 8 in FIG. 2 to drive the lens toward the infinite side. In this case the power supply E
Is applied to the motor M1 and A is also operated at the fastest speed possible. When driven to the in-focus position, the D and output terminals become low level and AND gate according to the calculation result of the AF circuit.
AN2 becomes low level output, OR gate OR1 becomes low level output, transistor Tr3 is turned off via inverter IN8, Tr2 is turned on, the brake circuit of M1 → Tr2 → D2 → M1 is closed and motor M1 is stopped. At the same time, when the AF circuit is in focus, the F output terminal becomes high level and the flip-flop FF sends the high level output as the Q output and the low level input is made to the AND gates AN2 and AN3 via the inverter IN1. Even if the camera is moved from the in-focus subject, the AF motor R and E output terminals will not affect the output state of the AF motor M
1 continues to stop. To release the stop of the motor M1, when the finger is released from the release button 3 and SW1 is opened, a high level signal is input to the reset terminal R of the flip-flop FF, the Q output becomes low level, and the initial state is restored.

Next, the case where the lens is moved to the closest side of the calculation result of the AF circuit AF will be described. In this case, the E output terminal outputs a high level output and the OR gate OR2 outputs a high level output, so that the transistor Tr4 is turned on. On the other hand, since a low level output is sent from the D output of the AF circuit AF, the AND gate AN2 is a low level output, and since the switch SW2 is at the neutral point in the AND gate AN4, a low level signal is sent via the inverter IN2. Since it is input, AND gate AN4 is a low level output. Therefore, the OR gate OR1 sends a low level output and the transistor Tr2 is turned on.
Therefore, a current flows through Tr4 → M1 → Tr2, the motor M1 rotates in the reverse direction, and the focus lens group G1 is extended to adjust the focus to the near side. Focus adjustment is performed in this manner. When focusing, a low level output is generated from the E output terminal of the AF circuit AF, and AND gate AN3 becomes a low level output.
Since the OR gate OR2 becomes low level, the transistor Tr5
Turns on. Therefore, the brake circuit of M1 → Tr5 → D1 → M1 is closed and the motor M1 stops.

Next, the case of performing the power zoom operation will be described.
As shown in FIG. 1, the zoom operating member 4 at the left thumb position is operated in the camera hole state. When moving to the tele side, the operation member 4 is moved in the direction of arrow 5. Then, the switch SW2 of FIG. 3 is closed to the A side, and a high level signal is input to the AND gate AN6 via the inverter IN6. At this time, since the release button 3 is not operated, the switch SW
Since 1 is open, the other input of AND gate AN6 also becomes high level, and AND gate AN6 outputs high level. The AND gate AN7 becomes low level output, the transistors Tr7 and Tr9 turn on, current flows through Tr7 → M2 → Tr9, the motor M2 rotates in the forward direction, and the lens barrel 9 is extended by the worm 10 and the zoom lens group G2 in FIG. The zooming operation to the side is performed. When the operation of the operation member 4 is released during the zooming in this way, the switch SW2 becomes the neutral point B, the AND gate AN6 becomes the low level output, the transistor Tr6 is turned on and M2 → Tr6 → D4 → M2. The brake circuit of is closed and the motor M2 is stopped.

On the contrary, when moving to the wide side, if the operating member 4 is moved to the 6 side, the switch SW2 is closed to the C side, the AND gate AN7 outputs a high level, and the transistor Tr8 is turned on.
Also, at this time, since the AND gate AN6 is a low level output, the transistor Tr6 is turned on, current flows through Tr8 → M2 → Tr6, the motor M2 reverses, and the lens barrel 9 is retracted together with the zoom lens group flow 2 and zooming to the wide side is performed. Done.

Next, a case of performing power focus will be described. The power focus is used as an auxiliary to the auto focus, and when the focus is consciously adjusted finely without swinging the angle of view within the finder after it is in focus, or the AF circuit cannot measure the distance. It is used when Now, it is assumed that the autofocus is performed as described above to reach the in-focus state. In this case, the high level is sent from the F output terminal of the AF circuit, and the low level is input from the flip-flop FF to the AND gates AN2 and AN3 via the inverter IN1. Therefore, the AND gates AN2 and AN3 output the D or E output of the AF circuit. Low level output regardless of the output from the pin. At this time, the Q output of the flip-flop FF is input to the AND gates AN8 and AN9, so the state of the OR gate OR1 is determined by the output of the AND gate AN4, and the OR gate OR2 is set to the AND gate A2.
N5 determines its state. At this time, since the Q output of the flip-flop FF is at a high level, the transistor Tr11 is turned off, the transistor Tr12 is turned on, and the drive circuit to the motor M1 via the low voltage circuit H outputs a low potential voltage to the power source E. Is being supplied.

When finely adjusting the focus from this state toward the infinity side, the operation member 4 is operated to the arrow 5 side while the release button 3 is still pressed. In this state, SW1 in FIG. 3 is closed, a high level signal is input to one input of the AND gate AN4 via the inverter IN3, and the operating member 4
The switch SW2 is closed to the side A by operating the arrow 5 side, so that a high level signal is input to the other input terminal of the AND gate AN4 via the inverter IN2, and the AND gate AN4 outputs high level. Is sent. Therefore, the AND gate AN8 outputs a high level, the OR gate OR1 also outputs a high level, and the transistor Tr3 is turned on.
On the other hand, since the OR gate OR2 is maintained at the low level output, the transistor Tr5 is turned on, and the current supplied from the circuit H causes a current to flow from Tr3 → M1 → Tr5 to rotate the motor in the forward direction to finely adjust the focus to the infinite side. . At this time, since the voltage applied to the motor M1 has a low value, the lens is slowly driven to facilitate the fine adjustment. When the hand is released from the operating member 4 while fine adjustment is being performed in this way, the switch SW2 is connected to the neutral point B, so that the AND gate AN4
Becomes low level output, OR gate OR1 also becomes low level output, and Tr2 turns on. Then, the brake circuit of M1 → Tr2 → D2 → M1 is closed and the motor M1 is stopped. in this case
As the calculated value of the AF circuit, a high level is sent out from the E output terminal so as to return to the test side because it is out of focus, but since it is once in focus, the AND gate AN3 is at a low level by the Q output of the flip-flop FF. Holds the output state of. Therefore, in fine adjustment after focusing, driving in the focusing direction by the AF circuit is prohibited, and fine adjustment is performed based on the photographer's intention. To release the fine adjustment state, release your finger from the release button 3 and open the switch SW1. The high level signal is input to the reset terminal R of the flip-flop FF and the Q output becomes low level.
If the stroke operation is performed, the above autofocus is executed again. If fine adjustment is made to the closest side after focusing, moving the operating member 4 to the arrow 6 side closes the switch SW2 to the C side and the OR0 gate OR2 becomes a high level output, Tr4 → M1 →
A current flows through Tr2 and the motor rotates in reverse and the focus is finely adjusted to the near side.

When the AF circuit cannot measure the distance, the G output becomes high level and the flip-flop is set through the OR gate OR3, and the switch SW1 is operated by operating the member 4 with the switch SW1 closed as described above. Determine the state,
The lens is driven in the direction according to the state as described above, and the focus is manually adjusted to the power focus. In this case, since the switch SW1 is closed, a low level signal is input to the AND gates AN6 and AN7, the motor M2 remains stopped, and the zoom operation is not performed.

As described above, in the present invention, the power focus can be executed after focusing or when distance measurement is impossible. Therefore, when it is necessary to perform focus by focusing or after manual focusing is impossible. The power focus enables the focus.

Further, in the embodiment, the switch SW2 is operated and the release button is operated during the power zoom.
When SW1 is turned on, zoom operation is prohibited, and switch SW1 turns on to switch S during auto focus.
The zoom operation is not executed even when W2 is in the operating state. Therefore, during power zoom, the first and second release buttons
Even if the stroke is performed and the release operation is executed as is known, the driving of the lens system is fixed, so that a malfunction such as the driving of the lens system during exposure can be prevented.

<Effect> As described above, according to the present invention, since the auto focus and the power focus during the manual focus are switched in the above-described configuration, the auto manual focus of the operability is extremely good. The switching can be executed.

[Brief description of drawings]

FIG. 1 is an external view showing the external appearance of a camera having an autofocus / manual focus switching circuit according to the present invention, and FIG. 2 is a sectional view showing the internal structure of the camera shown in FIG.
FIG. 1 is a circuit diagram showing an embodiment of the autofocus / manual focus switching circuit of the present invention. M1 …… Motor SW1, SW2 …… Switch AF …… Auto focus circuit AN1 to AN9 …… And gate

Claims (1)

[Claims] 1. An autofocus mode in which an imaging lens drive circuit drives an imaging lens to perform a focusing operation based on a focus signal detected by a focus state detection circuit, and a manual operation member is operated. In a focus adjusting device having a manual focus mode in which the imaging lens drive circuit is operated by the formed operation signal to perform focusing by the imaging lens, the focus state detection circuit detects a non-focus state as a focus state. , Prohibiting the response of the imaging lens drive circuit to the operation of the manual operation member during the focusing operation based on the focus signal, prohibiting focusing based on the operation signal, and detecting the focus state When the circuit detects the focused state as the focus state, the manual The response of the imaging lens drive circuit to the operation of the operation member is allowed, the operation of the imaging lens drive circuit is operated by the operation signal by operating the manual operation member, and the imaging lens is driven based on the operation signal. A focus adjustment device comprising a mode switching circuit for switching.