JP2769609B2 - camera - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera, and more particularly, to a camera.
The present invention relates to a camera suitable for using a photographing lens that can be driven electrically and manually. 2. Description of the Related Art As a photographing lens capable of moving an optical system by electric driving and manual driving, automatic focusing and manual focusing are performed by switching means as disclosed in Japanese Patent Application Laid-Open No. 55-73025. There has been known one configured to selectively switch between focus and focus. In a camera using the above-mentioned conventional lens, some switching operation is required to perform a manual focusing operation during an automatic focusing operation, and quick switching can be performed. Did not. The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a camera which can quickly and automatically switch between an automatic and manual drive of a photographing optical system and has good operability. [0004] In order to solve the above-mentioned problems, a description will be given with reference to FIG. 2 showing an embodiment.
A camera according to claim 1, wherein the focus detection device (1) detects an in-focus state of a subject transmitted through the photographing lenses (L1, L2).
27), an autofocus mode in which the photographing lens is moved in the optical axis direction by an electric driving device (113) based on the detection result of the focus detection device, and an external operation member (1).
A control device (1) that controls a manual focus mode in which the photographing lens is moved in the optical axis direction according to the operation of (9).
11), wherein the external operation member (1) is provided.
A detection device (29) for detecting that an external operation member has been operated when an electric signal generated by the operation of the operation of (9) is detected a predetermined number of times within a predetermined time, and an auto focus in response to the detection of the detection device. In order to execute the manual focus mode also in the mode, a prohibition device (111) for prohibiting driving of the electric driving device is provided. According to a second aspect of the present invention, a photographing lens (L
1, L2), the focus detection device (127) for detecting the in-focus state of the subject transmitted through the lens, and the electric drive device (113) moves the photographing lens in the optical axis direction based on the detection result of the focus detection device. And a control device (111) for controlling an auto-focus mode for moving the image pickup lens in the optical axis direction in response to an operation of the external operation member (19). A first detection device (29) for detecting an operation of the member, and a prohibition for prohibiting the driving of the electric driving device in order to execute the manual focus mode even in the auto focus mode according to the detection of the first detection device. Equipment (111)
A second detection device (29) for detecting the end of the operation of the external operation member; and an electric drive for returning from the manual focus mode to the auto focus mode after a lapse of a predetermined time from the detection of the second detection device. A permission device (111) for permitting the driving of the device. According to the first aspect of the present invention, the camera has an external operation member (1).
The prohibition device (111) prohibits the driving of the electric driving device (113) when an electric signal generated by the operation of the operation (9) is detected a predetermined number of times or more within a predetermined time. Therefore, in the camera according to the first aspect, the manual focus mode can be promptly executed even in the auto focus mode, and the electric driving device (113) is driven by a slight movement of the external operation member (19). Is never banned. Therefore, the holding performance of the lens barrel does not deteriorate. In the camera according to the second aspect, when the operation of the external operating member (19) is detected, the prohibiting device (111) prohibits the driving of the electric driving device (113), and the external operating member (19) is inhibited. When the end of the operation is detected, the permission device (111) is driven by the electric driving device (11) after a lapse of a predetermined time.
The driving of 3) is permitted. Therefore, in the camera according to the second aspect, the auto focus mode can be executed after a lapse of a predetermined time after the interruption operation in the manual focus mode is completed. Therefore, there is no inconvenience that the movement of the external operation member (19) cannot be stopped even for a moment during the manual operation. FIG. 1 to FIG. 3 show an embodiment of the present invention, in which the present invention is applied to an automatic focusing lens barrel capable of performing automatic focusing and manual focusing based on the drawings. Will be described. The lens barrel shown in FIG. 1 can be mounted on a camera B having the automatic focus detection device shown in FIG. 2, and at the time of automatic focusing photography, the photographing optical system L1, L
2 is driven. In FIG. 1, a fixed cylinder 11 having a bayonet claw 11a for mounting on a camera body is an inner cylinder 11
d and an outer cylinder part 11e, and a straight-moving cylinder 15 holding the photographing optical systems L1 and L2 is fitted on the inner periphery of the inner cylinder part 11d. Further, a cam cylinder 13 having an external gear 13a constituting a part of a differential gear mechanism, which will be described in detail later, is rotatably fitted on the outer periphery of the inner cylinder portion 11d. A cam groove 13b provided in the cam cylinder 13
The sliding pin 47 implanted in the rectilinear barrel 15 is
The first inner cylindrical portion 11d is engaged with a straight guide groove 11c that is long in the optical axis direction and provided in the inner cylindrical portion 11d. As a result, the cam cylinder 1
The rotation of 3 causes the rectilinear barrel 15 to move along the optical axis together with the optical systems L1 and L2. A distance scale cylinder 60 is fixedly provided at the front end of the cam cylinder 13 so that the distance scale printed on the outer peripheral surface 60a can be read through a distance display window provided on the front fixed cylinder 21. Have been. In the conventional photographing lens, the set distance scale is generally provided on the manual operation member. However, in the case of the embodiment, there is no correlation between the position of the manual operation member 19a and the positions of the optical systems L1 and L2. Therefore, the distance scale cannot be provided on the manual operation member 19a. Therefore, in the embodiment, the distance scale 60 is fixedly provided at the tip of the cam barrel 13 which rotates in correlation with the movement of the optical systems L1 and L2, the distance scale is printed on the outer periphery 60a, and provided on the front fixed barrel 21. The distance is read from the distance scale window 21a. The distal end of the outer cylinder 11e of the fixed cylinder 11 (FIG. 1)
At the middle left end), a manual rotary cylinder 19 is fitted and supported.
The manual operation ring 19 includes an operation unit 19a that is operated externally, and a rotating barrel 19b that is linked to another barrel inside the barrel. Since the pin 27 that engages with the circumferential groove 11b formed in the outer cylinder portion 11e of the fixed cylinder 11 is implanted in the rotary cylinder 19b, the manual rotary cylinder 19 is guided by the circumferential groove 11b and the pin 27. , And is fitted and supported on the outer cylinder portion 11e so as to be rotatable only. A rubber ring 25 for preventing slippage is attached to the outer periphery of the operation part 19a.
At the rear end, a planetary gear 41 constituting a part of a differential gear mechanism described later is supported by a shaft 43. On the inner periphery of the outer cylinder portion 11e of the fixed cylinder 11, a first internal gear 17a meshing with the planetary gear 41 and a coupling shaft 37 rotated by a motor driving force (the driving force of the motor 113 in FIG. 2) are provided. Pinion gear 37 formed at one end
An internal gear cylinder 17 provided integrally with a second internal gear 17b meshing with the internal gear b is rotatably supported. The wave washer spring 49 for friction braking is sandwiched between the manual rotary cylinder 19 and the front fixed cylinder 21 fixed to the fixed cylinder 11, and a predetermined torque is applied to the manual rotary cylinder 19 by the frictional force. I have. A photo-interrupter 53 and a flexible printed circuit board 55 (hereinafter, referred to as an encoder 55) having an encoder pattern formed thereon, which is long in the circumferential direction, are fixed to the front fixed cylinder 21. The photointerrupter 53 has a cylindrical code plate 51 (a light-transmitting member provided at a constant interval in the circumferential direction) fixed between the light-emitting portion and the light-receiving portion at the tip of the rotating cylinder 19 b of the manual rotating cylinder 19. When the manual rotary cylinder 19 rotates, the pulse signal corresponding to the rotation of the manual rotary barrel 19 is transmitted to the CPU 29 in the lens. The encoder 55 has a code corresponding to the position of the sliding brush 57, that is, the angular position of the cam cylinder 13, when the sliding brush 57 fixed to the distal end of the cam cylinder 13 slides on its surface. A conductor pattern is formed so as to be output. That is, a signal indicating whether the optical systems L1 and L2 are at the infinity position, the close position, or another position is transmitted to the CPU 29 in the lens. The in-lens CPU 29 is connected to a lens mount contact pin 31 via a leaf spring 33, and the contact pin 31 and the leaf spring 33 are held by a contact housing 35 at the inner diameter of the mount. The clamp screw 45 screwed to the fixed cylinder 11 is configured to press the outer periphery of the internal gear cylinder 17 and prevent the rotation of the internal gear cylinder 17 by screwing. FIG. 2 is a schematic diagram schematically showing a system configuration in a state where the lens barrel A of this embodiment is mounted on a camera body B. The same parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 2, when the photographing lens A is mounted on the lens mount 141 on the camera body B via the bayonet claw 11a provided on the fixed barrel 11, the lens-side coupling shaft 37 becomes the camera-body-side coupling shaft 1
Combine with 25. The coupling shaft 125 is rotationally driven by a motor 113 controlled by a drive signal of a CPU (arithmetic processing unit) 111 in the body via a friction clutch 115 and reduction gear trains 121 and 123. The light from the subject that has passed through the photographing optical systems L1 and L2 is partially reflected by the movable mirror 129, and
An object image is formed on the object 33. The subject image is observed through a condenser lens 134, a pentaprism 135, and a finder eyepiece 136. Part of the light transmitted through the semi-transmissive mirror provided at the center of the movable mirror 129 is reflected by the sub-mirror 131 and a pair of light receiving devices (pupil division type automatic focus detection device) including an imaging lens 12
An image is formed on the light receiving surface 7. The signal photoelectrically converted by the light receiving device 127 is sent to the CPU 111 in the body, and the amount of defocus (the amount and direction of the image plane deviation from the planned focal plane) is determined according to the image forming state. The CPU 111 in the body includes the lens contact 3
In-lens CP via 3, 31 and body side contact 139
It is electrically connected to U29 and can read various information about the lens from the ROM in the CPU 29 in the lens. Therefore, information representing the image plane movement amount per coupling unit rotation amount is read out, and the motor drive amount necessary for focusing is obtained from the above-described defocus amount. When the motor drive is started, a pulse signal corresponding to the motor shaft rotation amount is generated by the code plate 119 and the photo-interrupter 117 provided on the motor shaft, so that a pulse corresponding to the required motor rotation amount is generated. At this point, the motor drive is stopped and focusing is performed. When the lens-side drive shaft 37 is rotated by driving the motor 113 controlled according to the imaging state of the photographing optical systems L1 and L2, the pinion gear 3 integrated with the drive shaft 37 is rotated.
7b rotates. The rotation of the pinion gear 37b is transmitted to the internal gear cylinder 17 via the second internal gear 17b of the internal gear cylinder 17, and the first internal gear 17a rotates about the optical axis.
The rotation of the first internal gear 17a causes the planetary gear 41 to rotate. In the case of only automatic focusing, since the rotation of the shaft 43 supporting the planetary gear 41 and the manual rotary cylinder 19 is suppressed by the frictional force of the friction braking spring 49, the rotation of the planetary gear 41 causes the external gear to mesh with the rotation. The cam cylinder 13 having 13a rotates. Accordingly, the rotational torque T1 of the manual rotary cylinder 19
And the rotational torque T2 of the cam cylinder 13 need to be set so that T1> T2. FIG. 3 is a sectional view taken along line III-III of FIG. 1, which is a main part of the differential gear mechanism. First, the operation of the differential gear mechanism during the automatic focusing operation will be described. In the case of automatic focusing from a long distance to a short distance, the cam cylinder 13 rotates clockwise together with the outer gear 13a by the counterclockwise rotation of the internal gear cylinder 17 in FIG. The sliding pin 47 that engages with the cam groove 13b by the rotation of the cam barrel 13 moves to the left in FIG. 1 while being guided by the straight guide groove 11c, and moves the straight barrel 15 and the photographing optical systems L1 and L2 to the left. Displaced toward Thereby, focus adjustment is automatically performed from infinity to a close distance. Conversely, when the automatic focusing is performed from a short distance to a long distance, the internal gear 17a rotates clockwise in FIG. 3 due to the reverse rotation of the pinion gear 37b, and the external gear 13a
At the same time, the cam barrel 13 rotates counterclockwise. As a result, the rectilinear barrel 15 and the imaging optical systems L1 and L2 move rightward, and automatic focusing to a long distance is performed. Next, the operation of the differential gear mechanism when the manual focusing operation is performed during the automatic focusing operation will be described. When the manual focusing operation is performed during the automatic focusing operation by the motor driving, the rotation of the internal gear cylinder 17 and the rotation of the planetary gear 41 by the motor driving, and the planetary gear 41 by the manual focusing operation are performed.
And the rotation of the cam cylinder 13 is combined (that is, the driving amount combining means). The configuration of the driving amount synthesizing means includes a cam cylinder 1 driven by a motor.
There is a case where the driving of the cam cylinder 13 and the driving of the cam barrel 13 by manual operation are simultaneously operated and combined, and a case where only one of them is operated selectively. Also, in the manual focusing operation, when the manual rotary cylinder 19 rotates, the planetary gear 41 similarly revolves around the optical axis while rotating around the shaft 43, and the amount corresponding to the operation amount of the manual rotary cylinder 19. Only by rotating the cam barrel 13, the photographing optical system L
1 and L2 are moved. Hereinafter, the operation of the present embodiment will be described in detail. First, during the automatic focusing operation, the photographing lens L
Let us consider a case where 1 and L2 reach the limit end at infinity or the closest position. In the case of a self-focusing lens barrel that does not have a general differential gear mechanism, when the photographing optical system reaches a limit end at infinity or a close position, the drive end of the motor stops because the limit is limited by the limit end. 2, the output pulse of the photo-interrupter 117 in FIG. 2 is no longer generated, and it can be detected that the photographing optical system has reached the limit end. But,
In the case of a lens barrel having a differential mechanism as in the embodiment, when the cam barrel 13 reaches the limit at infinity or the closest and the rotation of the cam barrel 13 is restricted by the limited end, the internal gear barrel 1 is driven by the driving force of the motor 113.
The rotation of the planetary gear 7 causes the planetary gear 41 to revolve, thereby rotating the manual rotary cylinder 19, so that it is not possible to detect that the drive shaft of the motor 113 has reached the limit end of the optical system without stopping. Therefore, in the embodiment, an encoder 55 for detecting the rotation angle position of the cam barrel 13 is provided.
In this way, the limit end of the photographing optical system at infinity or the closest position is electrically detected. That is, when the limit is reached, a code signal indicating that the limit has been reached is sent from the encoder 55 to the in-lens CPU 29. Then, a signal indicating that the taking lens has reached the limit end is transmitted from the CPU 29 in the lens to the CPU 111 in the body, and the control circuit of the CPU 111 in the body performs control for inverting or stopping the operation of the drive motor 113. . Next, consider a case where a manual focusing operation is performed during the automatic focusing drive of the photographing optical system. A case will be described in which the above-described driving amount synthesizing means selects driving by an automatic focusing operation or driving by a manual focusing operation. For example, when the contrast of the subject becomes low during the automatic focusing operation, or when the subject suddenly moves to increase the defocus amount, the defocus amount may not be obtained even when the focus detection is performed. . In such a case, it is necessary to manually perform the focusing operation. Therefore, the manual focusing operation is performed during the automatic focusing drive in a state where the defocus amount cannot be obtained. During the manual operation, the drive motor 113 is operated independently of the photographer's intention (for example, the automatic focusing operation is performed). If the operation is performed in response, there is an inconvenience that a desired manual operation cannot be performed. When a manual focusing operation is performed during the automatic focusing drive in a state where the defocus amount is obtained, the photographing optical system L
Since the actual movement amount of L1 and L2 is a combined amount of the motor drive amount and the manual operation drive amount, the number of pulses of the photointerrupter 117 and the movement amount of the photographing lenses L1 and L2, that is, the image plane movement amount (The amount of movement on the focal plane), and accurate focusing becomes impossible. Therefore, in the embodiment,
The operation of the manual rotary cylinder 19 is detected by the photo interrupter 53, and when the operation is performed, the automatic focusing drive of the photographing lens is stopped. That is, when the manual rotary cylinder 19 is operated,
In accordance with the rotation, a pulse signal is transmitted from the photo-interrupter 53 to the in-lens CPU 29. CP in this lens
U29 indicates that the photo italapter 53 has
If a pulse equal to or greater than a constant Δn is generated, it is determined that a manual focusing operation is being performed, and a signal for stopping motor driving (hereinafter, referred to as a servo inhibition flag) is transmitted to the CPU 111 in the body. This time Δt and the number of pulses Δn
When the value is extremely small, the motor 113 stops even with a slight movement of the manual rotary barrel 19, and therefore, when holding the lens barrel, it is absolutely necessary to avoid touching the manual operation ring 19 with the hand. The holding property of the lens barrel is deteriorated. If the value is extremely large, accurate focusing cannot be performed as described above. Therefore, the value must be appropriately large. As described above, if the manual focusing operation is performed during the automatic focusing drive, the servo inhibition flag is continuously output while the manual operation ring 19 is rotating, that is, while the manual operation ring 19 is being manually operated. The driving of the driving motor 113 is stopped. When the manual focusing operation is completed and the rotation of the manual operation ring 19 is stopped, switching is performed so that the servo inhibition flag is not output, and the automatic focusing operation by motor driving is restarted. However, the motor drive is started at the same time as the rotation of the manual operation ring 19 is stopped.
Then, since the movement of the manual operation ring 19 cannot be stopped even for a moment during the manual operation, the timing of stopping the output of the servo inhibition flag is determined by a predetermined time Δt ′ after the rotation of the manual operation ring 19 is stopped. You need to set it later. The value of Δt ′ may be fixed to a constant value, but it is assumed that the value of Δt ′ is optimal depending on the type, size, and shooting conditions of the lens. Therefore, the value of Δt ′ may be arbitrarily changed by the photographer using the changeover switch. Further, the motor drive may be restarted after a predetermined time Δt ′ from the point when the servo prohibition flag from the lens does not come on the program of the body-side CPU 111. When the automatic focusing lens barrel of the embodiment is mounted on a camera body that is not for automatic focusing, or mounted on a camera body for automatic focusing shown in FIG.
When the lens 5 is retracted (the manual focusing mode is selected), the lens-side coupling shaft 37 is free.
When the manual operation ring 19 is rotated for the manual focusing operation in this state, the internal gear cylinder 17
Is generally small, the cam barrel 13 does not rotate because only the internal gear barrel 17 rotates, and the optical system L1,
L2 does not move and manual focusing operation cannot be performed. Therefore, in the embodiment, the rotation of the gear tube 17 is restricted by screwing the clamp screw 45 during the manual focusing operation, thereby enabling the manual operation. It is also possible to provide a switch in conjunction with the screwing of the clamp screw 45, and to send a signal indicating that the manual operation is being performed from the lens to the body when the switch is clamped. As described above, FIGS.
Although the embodiment has been described based on the above, the present invention is not limited to this embodiment. For example, the distance scale display is performed by providing the distance scale cylinder 60 interlocked with the cam cylinder 13, but by increasing the number of positions that can be detected by the encoder 55, the output code of the encoder 55 can be used.
It is possible to know the rotational position of the cam barrel 13, that is, the shooting distance. Therefore, the value can be displayed on the lens side or the body side using a liquid crystal display element or the like. In the above-described embodiment, the detection of the limit ends of the photographing optical systems L1 and L2 during the automatic focusing drive is performed by the brush 57 and the encoder 55 provided on the cam barrel 13, but it is not always necessary to do so. For example, if the manual operation ring 19 can be allowed to rotate by a small amount when the photographing optical systems L1 and L2 reach the limit end during the automatic focusing drive, the detection of the limit end uses the output pulse of the photo interrupter 53. It is possible. That is, when the rotation of the cam cylinder 13 is restricted due to the mechanical restriction, if the drive motor 113 continues to rotate, the manual operation ring 19 starts to rotate. If the rotation is detected, the drive of the motor 113 can be stopped by knowing that the limit end has been reached. Further, in the above-described embodiment, the problem in the case where the drive amount combining means combines the drive by the automatic focusing operation and the drive by the manual focusing operation is described, and an example in which the combination is not performed (the manual operation ring 19). Although the operation of the motor 113 is stopped when is operated, it is not always necessary to stop the motor drive even if the respective drives are combined. For example,
When the manual operation ring 19 is manually operated, the operation amount and direction are electrically detected, and the number of output pulses of the photointerrupter 53 in the body is corrected based on the operation amount, so that the photographing optical system L1, If the correlation between the movement amount of L2 and the output pulse of the in-body photointerrupter 53 can be maintained, accurate automatic focusing drive can be achieved without stopping motor drive during manual operation. In the embodiment of the present invention, an example of an interchangeable automatic focusing lens barrel that can be mounted on a camera body for automatic focusing has been described. However, the present invention is not limited to this. The present invention is also applied to a lens barrel for automatic focusing having a driving motor for a photographing optical system in a cylinder, and other mechanisms such as a power focus (focusing device driven by a motor) and a power zoom (zooming device driven by a motor). Is applicable. As described above, according to the present invention, since the motor drive is stopped when the photographer operates the external operation member, the moving optical system moves only by manual operation.
Therefore, the feel of the manual operation is good (for example, the relationship between the manual operation amount and the image plane movement amount is constant), and the switching between the manual operation and the motor drive can be performed without any special switching operation. Can be greatly improved. Further, according to the embodiment, when the automatic focusing is impossible or the automatic focusing is uncertain, only the manual operation ring is operated even during the automatic focusing driving (that is, as in the conventional camera system). , Without having to operate the switch between the automatic focusing mode and the manual focusing mode), it is possible to quickly operate near the focal point by the manual focusing operation. Since it is possible to return to the driving and automatically drive to the focal point, the same focusing operation can be performed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drawing showing a cross-sectional view of a lens barrel capable of automatic focusing and manual focusing with a differential gear mechanism according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a system configuration when a lens barrel is mounted on a camera body for automatic focusing. FIG. 3 is a drawing showing a cross-sectional view taken along the line III-III of FIG. 1; [Description of References] 13, 41, 17 Differential gear mechanism 55, 57 Moving end detecting means 19 Manual operation ring 51 Code plate (manual operation detecting means) 53 Photointerrupter (manual operation) Detecting means) 45 Clamp screw 49 Wave washer spring for friction braking

Continuation of the front page (56) References JP-A-58-7110 (JP, A) JP-A-58-224341 (JP, A) JP-A-62-937 (JP, A) JP-A-58-46329 (JP) , A) Japanese Utility Model Application Showa 56-71668 (JP, U) Japanese Utility Model Application Showa 57-170107 (JP, U) Japanese Utility Model Application Showa 61-137221 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB (Name) G02B 7/11

Claims (1)

(57) [Claims] A focus detection device that detects an in-focus state of a subject that has passed through a shooting lens; and A control device that controls a manual focus mode in which the photographing lens is moved in the optical axis direction in accordance with an operation of the external operation member, wherein an electric signal generated by the operation of the operation of the external operation member is A detection device that detects that the external operation member has been operated when it is detected a predetermined number of times or more within a predetermined time; and in response to the detection of the detection device, to execute the manual focus mode even in the autofocus mode. A prohibition device for prohibiting driving of the electric driving device. 2. A focus detection device that detects an in-focus state of a subject that has passed through a shooting lens; and A camera configured to control a manual focus mode in which the photographing lens is moved in the optical axis direction in accordance with an operation of the external operation member; a first detection device configured to detect an operation of the external operation member; In response to the detection of the first detection device, in order to execute the manual focus mode also in the auto focus mode, a prohibition device that prohibits the driving of the electric driving device, A second detection device for detecting the end, and after a lapse of a predetermined time from the detection of the second detection device, the manual focus mode Wherein in order to return to the auto focus mode, the camera, characterized in that and a permission unit for permitting the driving of the electric drive.