JPH046928B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a lens barrel having a photographing distance range setting device that is capable of selecting any one of a plurality of distance ranges each included within a total photographing distance range. In order to speed up the focus adjustment of an automatic focusing device, Japanese Patent Application Laid-Open No. 127626/1984 divides the photographing range into long distance, middle distance, and short distance, and selects one of them. By configuring it so that it can be specified, the photographer can specify one of the three shooting areas mentioned above at the beginning of shooting, the shooting lens is first driven to the specified area, and automatic focusing control is performed from there. It's summery. However, in the above-mentioned Japanese Patent Application Laid-Open No. 55-127626, automatic focusing is forcibly driven to the desired shooting area at the beginning of shooting, and automatic focusing control is started, but after the start, a restriction is placed so that the shooting lens does not come out of the desired shooting area. Since there is no means to do so, if an object other than the main subject enters the focus detection area or the focus detection area is affected by camera shake, the shooting lens may be controlled to focus on an area outside of the desired shooting area, or the entire area may start to be controlled. There is a problem that In addition, another Japanese Patent Application Laid-open No. 54-113334 discloses a device equipped with a focus detection device using a contrast detection method. , and detect the maximum contrast position only within the desired distance range determined by the distance range selection section (conversely, even if the maximum contrast is detected outside the desired distance range, it is ignored), The camera is configured to perform focus alignment by moving the photographing lens to this maximum contrast position. The desired distance range referred to here simply refers to the range determined to find the maximum contrast position within which the focus detection device scans the entire area for focus detection. It does not limit the driving of the photographing lens or limit the scanning range during focus detection. Therefore, in the conventional example described above, there is no structure that limits the driving of the photographic lens, and furthermore, it is not possible for the photographer to select the desired photographing range from among the entire photographing range of the photographic lens. There is a problem that the shooting range cannot be set. In order to solve the above-mentioned conventional problems, the applicant divides the shooting range into multiple parts as shown in Table 1, and by selecting one of them, focuses only on the subject within the selected shooting range. We devised a device to drive the photographic lens to do this. However, if the total driving range is divided into several ranges, for example, the following Q ₁ ~ Q ₂ , Q ₂ ~ _{Q 3} , Q ₃ ~
Divide into three distance ranges such as Q ₄ , and if the target subject may exist between Q ₁ and _{Q 2} , set the scan switch to "Near", _and
In a configuration where the setting is set to ``Medium'' when the distance is between Q <sub>3</sub> and ``Far'' when the distance is between Q ₃ and Q ₄ , the subject is near the boundary point of each distance range, that is, near Q ₂ or Q ₃ . If the subject moves around, it may become impossible to achieve sufficient focusing, which may even be inconvenient.

[Table] In order to solve the above-mentioned disadvantages, the present invention is configured to focus only on objects within a selected distance range, and also to partially overlap appropriate adjacent distance ranges. An object of the present invention is to obtain a lens barrel having a photographing distance range setting device formed by the above method. Another object of the present invention is to obtain a lens barrel having a photographing distance range setting device that limits the scanning range of the photographic lens, eliminates unnecessary scanning, and shortens the scanning time. Hereinafter, the present invention is a further improvement of the division method shown in Table 1 when dividing the imaging range, and will be specifically explained using the drawings. In FIG. 1, a camera 1 equipped with an automatic focusing device according to the present invention is shown at the right end, and the closest position seen from the camera 1 is P ₁ , ∞
Let the position be P ₅ , and from the closest position P ₁ to the ∞ position P ₅
Camera 1 sets the boundary points as P ₂ , P ₃ , and P ₄ in order.
The focus-adjustable range of the field of view is appropriately divided into four parts. FIG. 2 is a principle diagram of an embodiment of the present invention, in which a pair of re-imaging lenses 3 and 4 are arranged symmetrically with respect to the optical axis of an objective lens 2 for photographing. The light beams are guided onto the light-receiving surfaces of a pair of photoelectric elements 5 and 6 via re-imaging lenses 3 and 4, respectively. The pair of photoelectric elements 5 and 6 act as a photoelectric exchanger for detecting the image position, and are specifically composed of a photoelectric element array. The processing circuit 7 inputs output signals from a pair of photoelectric element arrays from terminals a and b, and compares them to determine front pin, rear pin,
and determine the in-focus state, and based on the results,
A motor 9 connected to this circuit 8 and terminals f and g is driven via a motor drive circuit 8 connected to terminals d and e, and the objective lens 2 is moved to the in-focus position by rotation of the gear head 10. On the other hand, the conductive member 11 is a member that moves in conjunction with the objective lens 2, and is conductive when the objective lens 2 is at a drive position focused on _P1 (hereinafter referred to as a position corresponding to _P1 ). The member 11 is in the position of the electric contact 13, when it is in the position corresponding to P ₂ it is in the position of the electric contact 14, when it is in the position corresponding to P ₃ it is in the position of the electric contact 15, and in the position corresponding to P ₄ . Sometimes at the location of electrical contact 16,
When in the position corresponding to P ₅ , the conductive member 11 is located at the position of the electrical contact 17 . This conductive member 11 serves as electrical contacts 13, 14, 15, 1
When the electrical contact 12 comes into contact with any one of the electrical contacts 6 and 17, the electrical contact 12 becomes equal in potential to the electrical contact with which it comes in contact via the conductive member 11. The electrical contact 13 is always in the Vcc state, and the electrical contact 17 is always in the ground state. The other electrical contacts 14, 15, 16 are controlled by a scanning member 19 for selecting the shooting distance range, respectively.
It can be in either Vcc, ground, or open state. The states of the electrical contacts 13 to 17 are transmitted to the electrical contacts 12 via the conductive member 11, and this information is transmitted from the input terminal c to the processing circuit 7 through the conducting wire 18. When the output signal of the conductor 18 is Vcc, the processing circuit 7 connects the objective lens 2 via the motor drive circuit 8.
outputs a signal to rotate the motor 9 so that it moves from the closest side to the ∞ side (to the right in the figure), and when the output signal of the conductor 18 is ground, the objective lens 2
outputs a signal so that it moves from the ∞ side to the closest side (toward the left in the figure). Note that detailed explanations regarding the processing circuit 7 and motor drive circuit 8 can be found in Part 3.
This will be done later using FIG. The configuration of the switch section for selecting the photographing distance range will be explained. The selection switch section is designed to allow selection of four stages, F, M, N, and FULL, using the operating member 19. The conductive member 2 is connected to the insulating operating member 19 at a certain interval.
0, 21 are fixed, and the selection switch part is connected to the other electrical contacts 22, to which Vcc is applied.
Electrical contact 23 to which ground is applied, electrical contact 2
4 to 31 (contacts 24, 25, 2 indicated by broken lines)
8 and 31 may be omitted. ). FIG. 2 shows a state in which the operating member 19 is set to M. As shown in FIG. In this state, the conductive members 20 and 21 fixed to the operating member 19 at a constant interval are in contact with the electrical contacts 26 and 30, respectively, so that the electrical contact 14 receives Vcc and the contact 16 receives Vcc. Ground is applied to each.
Therefore, in this state, the conductive member 11 moves between the electrical contacts 14 and 16, and the objective lens 2
will move between the positions corresponding to P ₂ and P ₄ .
Note that even if the initial position of the objective lens 2 is not between the positions corresponding to P ₂ and P ₄ , once it passes the position corresponding to P ₂ or P ₄ , from then on it will only move within the desired range. Move. This will be explained in detail later. Similarly, when the operating member 19 is set to F, the electrical contacts 13 and 15 become Vcc and the contact 17 becomes ground, the conductive member 11 moves between the electrical contacts 15 and 17, and the operating member 19 is set to N. When set to , the electrical contact 13 becomes Vcc, the contact 15 becomes ground, and the conductive member 11 moves between the electrical contacts 13 and 15. When the operating member 19 is set to FULL, the electrical contact 13 is always connected to Vcc, the contact 17 is always connected to the ground, and the contacts 14 to 16 are open, so the conductive member 11 moves between the electrical contacts 13 and 17. It turns out. These relationships are expressed using a table as shown in Table 2 below.
become that way.

[Table] As shown in Table 2, the operating member 19 is F,
Since the shooting distance ranges when set to M, N, and FULL partially overlap, even if the subject is moving around, for example, near boundary point _P3 of the distance range when set to F, The photographer can safely set the operating member 19 to M without hesitation in selecting the distance range, and can quickly take a sufficiently focused photograph of the desired subject. in this way,
Not only when the subject is not near the boundary point of the distance range, but also when the subject is near the boundary point of a certain distance range,
A distance range within which the subject is likely to be captured can be selected, and photography can be conveniently carried out. In the above embodiment, the reimaging lenses 3, 4, photoelectric elements 5, 6, processing circuit 7, and power source (see FIG. 4) are provided in the camera body or in a viewfinder attached to the body. In the present invention, the camera body itself, or when the exchangeable viewfinder is removably attached to the camera body, the camera body and the exchangeable viewfinder are collectively referred to as a camera. The above-mentioned embodiment shows an example in which elements 3 to 7 and a power source (see FIG. 4) are provided in the camera, and all other elements are provided in an interchangeable lens barrel that is detachable from the camera.
Contacts c, d, and e are for electrical connection between the lens barrel and the camera. FIG. 3 shows an example of the processing circuit 7 shown in FIG. 2, and the input/output terminals a, b, c, d, and e in the figure are common to those in FIG. Outputs from photoelectric elements 5 and 6 are input to input terminals a and b, respectively. On the one hand, those values are input to comparators 101 and 102 via a differential amplifier 100, and the threshold voltages V _r ⁺ ,
Compared to V _r ^- . On the other hand, it is input to comparators 111 and 112, compared with a threshold voltage V _r ⁺ , and its output is input to an OR gate 113. And the above comparators 101, 10
2 and the output of gate 113 is NAND gate 11
4, the gate 114 outputs L when focusing, and outputs H in other cases. Therefore, when the output of gate 114 is L, both gates 115 and 116 output L regardless of the output of flip-flop 110, and when the output of gate 114 is H, the output of flip-flop 110 is low. Print the output. Furthermore, the outputs of gates 101 and 102 are also input to gates 108 and 109, and the flip
It is output via the flop 110 as a signal instructing the rotation direction of the motor 9. Further, Vcc, open, or ground is applied to the input terminal c according to the position of the objective lens 2, and gates 103 and 104 are applied to the input terminal c.
receives the Q and output of flip-flop 110, and the output of a group of transistors that varies depending on the C input, and inverts the output of flip-flop 110. Now, when the terminal c is open, Vcc is input to the gates 103 and 104 through the conductive wires 105 and 106, but when Vcc is applied to the terminal c, the ground is input to the gate 104 through the conductive wire 106. Therefore, flip flop 1
Only when the output of the gate 10 is L, that is, when the motor 9 is driving the objective lens 2 from infinity to close range, the output of the gate 104 becomes the output of the gate 109.
The output of flip-flop 110 is inverted via the flip-flop 110. Note that even if the terminal c is applied to Vcc, the flip-flop 110 will not be reversed if the rotation direction of the motor 9 is reversed. Similarly, terminal c
When the ground is applied to the gate 103, the ground is input to the gate 103 through the conductor 105. Therefore, only when the motor 9 is driving the objective lens 2 from close range to infinity, the output of the gate 103 becomes a flip-flop. 110 is inverted.
Thus, the outputs of flip-flop 110 and gate 114 are input to AND gates 115 and 116, and the outputs are transmitted to terminals d and e.
In the out-of-focus state, the terminals d and e output different signals, either H or L, depending on the direction in which the objective lens 2 is driven. In the focused state, both terminals d and e become L. FIG. 4 shows the motor drive circuit 8 shown in FIG.
In this example, the input terminals d and e in the figure are
The output terminals f and g are the same as those in FIG. 2. When both terminals d and e are at L, transistors 120 and 122 are off, and transistor 1
Since terminals 21 and 123 are turned ON, terminals f and g are short-circuited, and the motor 9 connected between them is stopped. When terminal d outputs H and terminal e outputs L, transistors 121 and 122 are on, transistors 120 and 123 are off, and current flows from terminal g to terminal f via motor 9. 9 rotates so as to move the lens 2 to the left in FIG. When the terminal d is L and the terminal e outputs H, the opposite is true. The operation will now be explained based on the explanation of FIGS. 2 to 4. As an example, the objective lens 2 is between the position corresponding to P ₁ and the position corresponding to P ₂ , and the subject is between P 2 and P ₂ .
The selection distance range is considered from an initial state in which the operating member 19 is set to M as shown in _FIG . The rotation of motor 9 is determined by the initial state of flip-flop 110. For example, if the output Q of the flip-flop 110 is L, the output is H, and the camera is out of focus, the terminal d outputs L and the terminal e outputs H. Therefore, the motor 9 rotates so as to move the lens 2 to the right in FIG. and lens 2
Beyond the position corresponding to P ₂ . That is, when the conductive member 11 crosses the electrical contact 14, the outputs of the terminals a and b become equal, and if both the terminals a and b have a certain level of output, the object is in focus. Therefore, the outputs of the output terminals d and e of the processing circuit 7 both become L, and the motor 9 stops. In addition, in the above initial state, the initial state of the flip-flop 110 is such that the output Q is H and the output is L.
, the terminal d outputs H and the terminal e outputs L. Therefore, motor 9 is connected to lens 2.
Reverse it so that it moves to the left in Figure 2. When the lens 2 reaches the position corresponding to P ₁ , that is, when the conductive member 11 reaches the electrical contact 13, the terminal d
is reversed to L, and terminal e is reversed to H, so that the lens 2 begins to move to the right in FIG. In this way lens 2
exceeds the position corresponding to P ₂ and becomes in focus as described above, output terminals d and e of processing circuit 7 both output L, and motor 9 stops. In this way, whatever the initial position of the lens 2, the lens 2 enters the drive range corresponding to the selected distance range and comes into focus within this range. Next, FIG. 5 shows an embodiment of the principle shown in FIG. 2, in which a pair of re-imaging lenses 3,
4. This is an example in which everything except the photoelectric elements 5, 6, and the processing circuit 7 is incorporated into the lens barrel. Components having the same functions as those in the principle diagram shown in FIG. 2 are indicated using the same numbers or symbols as in FIG. 2. Since the principle of the present invention has already been explained using FIG. 2, the explanation will be kept brief here. In the figure, 40 to 49 are photographing objective lenses. 8 is the motor drive circuit, 9 is the motor, 1
0 is a gear head, and a lens support portion 51 is driven via a final gear 50 that rotates around the optical axis. It should be noted that lenses 43 to 45 among the objective lenses are lenses that are moved by a support member 51 to adjust the focus. The conductive member 11 is the objective lens 4
A member that moves in conjunction with lenses 3 to 45, and the objective lens 43 is
It contributes to output a signal representing the position of ~45. The operating ring 52 is used to select the shooting distance range, and by rotating this to a predetermined position, a member 53 (corresponding to 19 in FIG. 2) directly connected to this rotates, and its tip A conductive member 54 (corresponding to 20 in FIG. 2) attached to the conductive member 54 (corresponding to 20 in FIG.
) moves to a predetermined position and the electrical contact group 55
(corresponding to 22 to 31 in FIG. 2) to output a desired signal. The principle of the entire switch section for selecting this photographing range is as shown in FIG. Figure 6 shows one example of a case where the electrical transmission part inside the lens barrel shown in Figure 5 is implemented using a flexible printed board, and is intended to be incorporated into the example shown in Figure 5. . In the figure, 63 is a portion of a motor drive circuit, which corresponds to the circuit 8 in FIGS. 2 and 5. 64 is a part that outputs a signal representing the position of the objective lens, and a surface 70
electrical contacts 12 to 17 in FIG.
This is the part corresponding to . Reference numeral 65 denotes an electrical contact part of the switch section for selecting the shooting distance range, which corresponds to the electrical contacts 22 to 31 in FIG. 2 and the electrical contact group 55 in FIG. 5. FIG. 7 is an external view of the lens barrel 56 shown in FIG. Note that in this embodiment, an example is described in which the shooting distance range of the subject is divided into four areas.
Regarding the number of divisions, it goes without saying that it is possible to implement it by providing a photographing range selection switch corresponding to the number of divisions, whether it is more than four regions or less than four regions. In the embodiment, the distance range (P ₁ to P ₃ ) and the distance range (P ₂ to _{P 4} ) are set so that they overlap, and the distance range (P ₂ to P ₄ ) and the distance range (P ₃ to P ₅ ) overlap with each other. It is being However, as shown in Table 3, a distance range (P ₁ -P ₂ ) may be set instead of the distance range (P ₁ -P ₃ ). That is, the present invention

[Table] It is sufficient that a pair of adjacent distance ranges at least overlap each other. Also, in this example, the signal indicating the restriction is
I used Vcc and ground, but any signal will do as long as they can be distinguished from each other. As for the distance measurement method, although the TTL method was used in the explanation in this embodiment, it can also be implemented in an automatic focusing device using other distance measurement methods such as an external light method or an active method. As described above, according to the present invention, by partially overlapping the distance ranges to be selected, it is possible to cope with the inconvenience when the subject moves around the boundary of the distance ranges to be selected as in the conventional method. In addition, the camera is provided with focus detection means consisting of elements 3 to 6, etc., and control means consisting of element 7, etc., and
Drive means and elements 11 to 17, 19 consisting of 10 etc.
If the selection means consisting of .about.31 etc. is provided in the interchangeable lens barrel, automatic focus adjustment can be performed by the focus detection means and control means of the camera no matter what kind of automatic focus adjustment interchangeable lens is attached. Moreover, an appropriate distance range can be set for each type of interchangeable lens with different focal length, lens extension amount, etc.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the spatial position of the subject,
FIG. 2 is a diagram showing the principle of an embodiment according to the present invention, and FIG. 3 is a circuit diagram showing an example of a processing circuit.
FIG. 4 is a circuit diagram showing an example of a motor drive circuit, FIG. 5 is a diagram showing a specific example when the device according to the present invention is incorporated into a lens barrel except for a part, and FIG. 7 is an external view of an example of a flexible printed board of the electric transmission part when the device according to the present invention is installed inside the lens barrel except for a part, and FIG. FIG. 2 is an external view of an example of a lens barrel when it is assembled into a cylinder. [Explanation of symbols of main parts] Focus detection means...
3 to 6, driving means...8 to 10, selection means...1
1-17, 19-31, control means...7.

Claims (1)

[Scope of Claims] 1. Includes a focus detection means for detecting a focus state using light passing through a photographic lens, and a control means for controlling the photographic lens to a focus position based on a focus detection signal from the focus detection means. A lens barrel that is used with a camera and has a photographing distance range setting device, comprising: a driving means for driving the photographing lens in response to a control signal from the control means; ,
signal generating means for generating range end signals respectively indicating at least two predetermined first and second photographing distance ranges; selecting one photographing distance range from the first and second photographing distance ranges; Once the photographing lens enters the selected photographing distance range, based on the range end signal of the signal generating means, so that the photographing lens focuses only on the subject within the selected photographing distance range. and a selection means for transmitting a restriction signal for restricting going outside to the control means, the first and second photographing distance ranges being adjacent to each other,
What is claimed is: 1. A lens barrel having a photographing distance range setting device characterized in that a part of each range overlaps and other ranges are set in advance so that they do not overlap with each other.