JPH0612371B2 - Focusing lens moving device in fixed front zoom lens - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens moving device for a front lens fixed zoom lens used in a video camera or the like, and more particularly, to a so-called variable power lens position at the time of so-called power focus for performing a manual focusing operation. The present invention also relates to a focusing lens moving device that controls the moving speed of the focusing lens according to the position of the focus adjusting lens (hereinafter referred to simply as the focusing lens).

2. Description of the Related Art As is well known, the front lens fixed zoom lens has a focusing lens that can be moved for focusing operation compared to a rear lens fixed zoom lens, which is a general zoom lens. Since it is located on the side, a small and light lens can be used as the focusing lens, and the amount of movement is small, and the amount of movement is smaller as the set focal length becomes wider, and the zoom lens It has the advantage that the shooting limit on the near point side can be eliminated by adjusting the focal length by moving.

By the way, when looking at the moving means of the focusing lens in the lens device used in the optical device regardless of the above-mentioned front lens fixed zoom lens, as is well known, the means for making use of the drive of the motor has become extremely popular. ing.

For example, Japanese Patent Application Laid-Open No. 53-116828 discloses a detector for detecting a variable amount of a variable lens to obtain a variable signal, and a detector for automatically measuring a distance to an object to obtain a distance signal. An arithmetic unit for processing output signals obtained from both the detection devices based on a predetermined function, and a unit for appropriately moving a lens group forming the zoom lens by a motor based on the arithmetic result of the arithmetic unit, are provided. A focusing method in a front-lens fixed zoom lens that automatically compensates for the fluctuation of the distance and the fluctuation of the distance to the subject is shown.

On the other hand, considering the movement operation of the focusing lens itself by the motor, as described in JP-A-53-116828 mentioned above, the focusing lens is automatically moved to an appropriate position based on the signal from the means for detecting the distance to the subject. It can be considered to move the so-called auto focus and the manual power focus described at the beginning.

By the way, the moving speed of the focusing lens by the motor at the time of the auto focus and the power focus is set to be relatively high on the basis of the moving speed at the time of the auto focus if the motor is also used. It is conceivable that the moving speed of the focusing lens at that time will be a speed at which manual operation is difficult.

That is, the photographer performs a manual operation while confirming the image-forming state, recognizes the image-forming state intended by the photographer, stops the manual operation, stops the driving of the motor, and changes the desired image-forming state. Even if an attempt is made, the moving speed of the focusing lens by the motor is too fast to obtain a desired image formation state, and it becomes extremely difficult to smoothly perform the power focus operation as described above. I think that the.

Therefore, in consideration of the above problems, for example, Japanese Patent Laid-Open No.
A focusing device as disclosed in Japanese Patent Publication No. 9-200205 is known.

The apparatus disclosed in Japanese Patent Laid-Open No. 59-200205 is simply described by focusing a focusing lens at a speed suitable for preset power focus operation by detecting a manual operation performed during power focus operation. It is characterized by comprising a motor drive speed control means for automatically controlling the operation of the motor so that the motor moves.

Therefore, during power focusing, the moving speed of the focusing lens is controlled to a speed at which the power focusing operation described above is easily performed, and the power focusing operation can be performed smoothly.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, even in the device disclosed in Japanese Patent Laid-Open No. 59-200205, the moving speed of the focusing lens set at the time of power focus is set by manual operation at the time of power focus operation. It is set by detecting the operation, and therefore the speed becomes easy for a single power focus operation, so if the lens target is the front lens fixed zoom lens mentioned at the beginning,
It still has the following problems.

That is, considering the movement characteristics of the focusing lens in the front fixed zoom lens, the set focal length becomes shorter as it goes to the short focus side (hereinafter simply referred to as the wide side), as described above. If the moving speed of the focusing lens at the time of power focus is constant as in JP-A-59-200205, the operability of the power focus operation varies depending on the set focal length, that is, the in-focus state is obtained. Therefore, there is a problem in that there is a difference in ease.

FIG. 8 is a focusing characteristic diagram showing the relationship between the subject distance obtained in the focused state and the focusing lens position when the variable power position in a general front fixed zoom lens is used as a parameter. The above problems can be understood more clearly from the figure. In addition, the W. M. T indicates the set focal length, W is the shortest that can be set, M is the middle that can be set,
T indicates the longest focal length that can be set, respectively.

Further, the numerical values indicated by 0, 0.5 and 1 are mere numerical values added to indicate the positions in the movable range of the focusing lens and the variable power lens, respectively, for convenience of explanation.

From the figure, for example, if the focus lens is moved to obtain the in-focus state for a subject 1 m away from the position set for an object at ∞, if the set focal length is T, from the point a in the diagram, It is necessary to move the focusing lens to the point b, the point c to the point d in the case of M, and the point e to the point f in the case of W. Here, looking at the movement amount of the husband and wife, in the case of T, the position of the focusing lens is from 0 to 1 shown by A in the figure,
That is, while it is necessary to move the entire movable range, the moving amounts of M and W may be smaller than the above-mentioned A indicated by B and C in the figure, respectively. become.

As a result, if the moving speed is constant, for example, if the moving speed is based on the moving amount of the set focal length T, then in the case of W, it will be too fast, and conversely, based on the moving amount of W. If it is moving speed, it will be too slow for T,
Further, even if the case of M is used as a reference, it is considered that the moving speed has less discomfort than that in the above case, but T or W
This is not the most preferable speed for the robot, which inevitably causes a difference in the operability of the power focus operation.

Furthermore, in order to take advantage of the characteristic of eliminating the shooting limit on the near side as a major feature of the front lens fixed zoom lens, the in-focus state cannot be obtained by moving the focusing lens at an arbitrary set focal length for the subject position. In the case of the extremely close position, if it is supposed that the in-focus state is obtained by moving the variable power lens, then simply thinking, the in-focus lens has 0 to 1 in the figure regardless of the set focal length. The entire movable range indicated by A will be moved.

Therefore, the condition that is slightly different from the explanation that the amount of movement of the focusing lens is different for the subject 1 m ahead is a little different, but in any case, there is a difference in operability of the power focus operation, It is obvious that there is a difference in the ease of obtaining the focused state.

The present invention has been made in view of the above points, and provides a focusing lens moving device that has no difference in operability of power focus operation, in other words, has improved operability.

Means for Solving the Problems A focusing lens moving device in a front lens fixed zoom lens according to the present invention includes a motor serving as a drive source for moving the focusing lens, and a focusing lens close to the focusing lens when manually operated. Focusing operation instructing means for outputting a focusing operation signal for instructing an in-focus operation to a point or a far point side, and a zoom lens position of the front fixed zoom lens is detected and a zoom lens position signal is output. Variable magnification lens position detection means and a plurality of drive speed information of the motor preset corresponding to the variable magnification lens position are stored, and a variable magnification lens position signal output from the variable magnification lens position detection means. A speed setting unit that outputs the driving speed information corresponding to the received variable power lens position signal by being operated by receiving the focusing operation signal. It is configured to include at least motor drive control means for driving the motor at a direction and a speed based on the focus operation signal and the drive speed information by supplying the focus operation signal and the drive speed information.

The other focusing lens moving device in the front lens fixed zoom lens according to the present invention includes, in addition to the above-mentioned means, a focusing lens position detecting means for detecting the position of the focusing lens and outputting a focusing lens position signal. In addition to the above setting means, it stores a plurality of driving speed information of the motor preset corresponding to the position of the variable power lens and the position of the focusing lens, and the variable power lens position to be supplied. And a driving speed information corresponding to the focusing lens position signal.

Action Since the focusing lens moving device according to the present invention has the above-described configuration, during focusing operation by the motor based on manual operation, that is, during power focus operation, the focusing lens has a plurality of focusing lenses according to the zoom lens position. The movement is performed at the moving speed, and in the case of a single moving speed, it is possible to eliminate the difference in the operability of the power focus operation caused by the difference in the set focal length in the front lens fixed zoom lens, which is preferable. Operability will be obtained.

Furthermore, since the moving speed is also controlled by the position of the focusing lens itself, even when the distance measurement limit on the near point side is eliminated by moving the variable magnification lens, which is a major feature of the front fixed zoom lens, That is, if the near-point side limit is eliminated, the required amount of movement of the focusing lens increases even on the wide side, but even in such a case, suitable operability can be obtained without causing a difference in operability.

Embodiment 1 FIG. 1 is a block diagram showing the basic construction of an embodiment of a focusing lens moving device using a motor in a front lens fixed zoom lens according to the present invention, in which 1 is a focusing lens 6 when manually operated. The focusing operation instructing means of the focusing lens outputs an output signal instructing a focusing operation to a near point or a far point side including a direction signal instructing a moving direction of the lens. The variable magnification lens position detection means for detecting the position of the lens and outputting the variable magnification lens position signal is shown. Reference numeral 3 stores in advance a plurality of driving speed information of a motor 5 which is a driving source for realizing a suitable moving speed of the focusing lens 6 corresponding to the position of the variable power lens, and the variable lens position signal is set to the above-mentioned variable speed lens position signal. The speed setting means receives the output signal instructing the manual focusing operation from the instruction means 1 and operates to receive the output signal, and outputs the drive speed information corresponding to the received variable magnification lens position signal.
Reference numeral 4 denotes a motor drive control means for receiving the drive speed information output from the speed setting means 3 and the direction signal output from the focusing operation instructing means 1 to drive the motor 5 in the speed direction corresponding to the speed information and the direction signal. Shows.

Reference numerals 5 and 6 represent the motor and the focusing lens, respectively, as described above.

The operation of the focusing lens moving device in the front lens fixed zoom lens according to the present invention having the above-described basic structure will be described below. Before that, the driving speed of the motor 5 stored in advance in the speed setting means 3 is described. Let me give you some information.

As described above, the speed setting means 3 stores in advance a plurality of driving speed information of the motor 5 according to the zoom lens position, but the zoom lens position and the movement of the focusing lens 6 are described above. As described above, in the case of the front-lens fixed zoom lens, the focusing lens 6 according to the subject distance of 1 m or the set distance up to the set focal length, which is considered to be a general shooting scene, is used.
There is a difference in the required movement of the.

That is, there is a relationship in which it may be smaller on the wide side. Therefore,
If the moving speed of the focusing lens 6 is set to be slower toward the wide side, the operability is the same on the tele side and the wide side.
It is considered that the operability is suitable, and in the present invention, for example, the variable speed lens position L ₁ shown in the focusing characteristic diagram shown in FIG. The drive speed of the motor 5 is controlled in the relationship as shown.

It should be noted that the control of the drive speed of the motor 5 as described above is performed within an arbitrary time by controlling the drive pulse supply timing, that is, the drive pulse supply interval when a stepping motor is used as the motor 5, for example. It goes without saying that various means such as controlling the amount can be considered.

Now, regarding the operation of the basic configuration shown in FIG. 1, first, the operation when the set focal length is T, that is, when the variable power lens position is at the "0" position shown in FIG.

Now, assuming that the position of the focusing lens 6 is also the “0” position shown in FIG. 8, when the photographer operates the focusing operation means 1 to perform the focusing operation to the near point side by a manual operation, A direction signal indicating the near point side is supplied to the motor drive control means 4 and the variable magnification lens position detection means 2 operates to detect the "0" position and output a variable magnification lens position signal indicating the "0" position. And outputs it to the speed setting means 3. The speed setting means 3 is
It operates by receiving the variable power lens position signal indicating the "0" position, and outputs the information corresponding to the relative speed "1" as the driving speed information in accordance with the stored contents stored in advance in FIG. , To the motor drive control means 4.

The motor drive control means 4 drives the motor 5 in accordance with the direction in the operation of the focusing operation means 1, that is, the direction signal indicating the near point side and the drive speed information indicating the relative speed "1" described above. The focusing lens 6 moves to the near point side at the relative speed "1".

On the other hand, even in the same operation of the focusing operation instructing means 1 to the near point side, if the zoom lens position is at the position indicated by "0.5" in FIG. Reference numeral 2 supplies the variable speed lens position signal corresponding to "0.5" to the output speed setting means 3.

Therefore, unlike the above-mentioned case, the speed setting means 3 outputs the drive speed information indicating the relative speed "0.5" in FIG. 2 and supplies it to the motor drive control circuit 4, which results in the motor 5 as a result. Although it is in the same direction as in the case described above, it is driven at a speed as slow as "0.5", and of course the moving speed of the focusing lens 6 is also slow.

Although the above-mentioned operation is described as the movement to the near point side, even in the case of the focusing operation to the far point side, only the driving direction of the motor 5 is changed and the relationship of the driving speed is the same. It goes without saying that it will be.

Hereinafter, similarly, the driving speeds of the four types of motors 5 shown in FIG. 2 are appropriately selected according to the variable power lens, and the moving speed of the focusing lens 6 during the power focus operation is appropriately controlled. is there.

Needless to say, the driving speed of the motor 5 does not have to be limited to four, and can be set variously according to the characteristics of the variable power lens or the like.

Further, a part of the focusing operation means 1 and the motor drive control means in FIG. 1 and a part other than the motor 5 and the focusing lens 6 can be realized by a microcomputer, and an example thereof will be described below.

FIG. 3 is a schematic configuration diagram showing an embodiment in which a focusing lens moving device for a front lens fixed zoom lens according to the present invention is constructed by using a microcomputer. Indicate the same functional configuration.

In FIG. 3, reference numeral 7 is a fixed front lens 8, a variable power lens 9, and a fixed front zoom lens including a focusing lens 6, and 10 is a manually operated power focus which constitutes the focusing operation instructing means 1. The switch includes a switch 10a that is turned on when a focusing operation is performed on the far point side, a switch 10b that is turned on when a focusing operation is performed on the near point side, and a manual operation member 10c. Reference numerals 11 and 12 denote resistors that constitute the focusing operation instructing means 1 together with the power focus switch 10. Reference numeral 13 denotes a motor drive circuit for driving the motor 5 for driving the focusing lens 6, which of course constitutes a part of the motor drive control means 4.

Reference numerals 14 and 15 represent a variable power lens drive motor and a drive circuit for controlling the movement of the variable power lens 9.

Reference numeral 16 denotes a microcomputer (hereinafter, simply referred to as CPU) which constitutes the variable lens position detecting means 2, the speed setting means 3 and the like.
Is described).

Reference numerals 17 and 18 denote origin detection switches for detecting the origin position settings of the variable power lens 9 and the focusing lens 6, respectively. The switches 17 and 18 are the starting points of use of the focusing lens moving device according to the present invention, for example, shown in the figure. There is no inconvenience at the initial point when power is not supplied. P. It performs a reset function for operating U.

It should be noted that the motor 5 and the zoom lens driving motor 14 in this embodiment employ stepping motors. Therefore, the focusing lens 6 and the zoom lens 9 are located at the respective positions of the motor 5 and the zoom lens. C. as an integrated value of the number of steps for driving the driving motor 14, that is, the number of supplied driving pulses. P. It shall be obtained within U16.

As for the configuration for controlling the moving operation of the variable power lens 9, for example, a configuration similar to that of the focusing operation instructing means 1 described above is provided, but it is omitted because it is not directly related to the present invention.

The operation of the apparatus shown in FIG. 3 will be briefly described below.

When a power supply (not shown) is supplied, the C.I. P. U1
Reference numeral 6 denotes a drive control circuit 1 for the motors 5 and 14 which drive control signals for moving the focusing lens 6 and the variable power lens 9 to the origin position from output terminals P ₁ and P ₂ , respectively.
Output to 3, 15.

When the variable power lens 9 and the focusing lens 6 reach the origin position, the origin detection switches 17 and 18 are turned on, respectively. P. U
Reference numeral 16 denotes the number of drive pulses supplied to the drive control circuits 13 and 15 of the motors 14 and 5 while detecting the turning on of the respective switches 17 and 18 at the input terminals i ₃ and i ₄ and stopping the output of the above-mentioned control signals. The memory unit for accumulating is reset to 0, and then the normal photographing operation is started.

That is, as for the photographing operation, in addition to the power focus operation which is the object of the present invention, the movement operation of the respective lenses 9 and 6 by a known autofocus device is performed. Note that the operation of the autofocus device is not related to the present invention, so a description thereof will be omitted.

Now, assuming that the switch 10b is turned on by the operation member 10c of the power focus switch 10 of the focus operation instructing means 1 to move the focus lens 6 to the near point side, C.I. P. U16 detects that the switch 10b is turned on at the input terminal i _1, and outputs the drive speed information in response to the position of the variable power lens 9 described in FIG. 1 to the output motor drive circuit 15 by the speed setting means provided therein. Will be supplied.

As a result, the drive speed of the motor 5 is controlled and the focusing lens 6
The moving speed of is also controlled according to the position of the variable power lens 9.

On the contrary, when the switch 10a of the power focus switch 10 is turned on to move the focusing lens 6 to the far point side, C.I. P. U16 detects the ON of the switch 10a at the input terminal i _2, since, allowed to move at a moving speed corresponding to the position of the variable power lens 9 focusing lens 6 performs the same operation when the near point side of the It will be.

Since the stepping motor 14 is used as a drive source for controlling the position of the variable power lens 9 as described above, the contents of the memory unit for integrating the number of drive pulses supplied to the stepping motor 14 are described. C.E. P. It goes without saying that it can be obtained within U16.

Further, when the stepping motor 14 is not used, the C.I. P. It is also clear that it is sufficient to input the zoom lens position information into U16.

The operation has been briefly described above. P.
One embodiment of the operation of U16 will be described with reference to the flowchart of FIG. 4 showing only the loop of the main part.

In this example, stepping motors are used as the motors 5 and 14 shown in FIG. 3, and the motor 5 is driven such that the time period measured by the timer operates as the drive pulse supply stop period. .

The flowchart of FIG. 4 will be described below. Steps 401 and 402 are steps for detecting the operation of the focusing operation means 1, and when the switch 10a of the power focus switch 10 is turned on by the operation member 10c, the C.I. P. The input terminal i _{2 of} U becomes low level, and the operation of the switches 10a and 10b is detected.

That is, when the switch 10b for instructing the movement to the near point side is turned on, 401, and when the switch 10a for instructing the movement to the far point side is turned on, in step 402, the input terminal i ₁ = 0, i ₂ = 0 will be detected,
When the above state is detected, step 403 or 404 will be selected next.

Step 403 or 404 is a step for confirming the completion of time counting by the above-mentioned timer, and when it is in the completed state, step 405 or 406 is selected.

That is, the above steps 403 and 404 are steps to confirm whether or not the period in which the supply of the drive pulse to the stepping motor 5 is stopped has passed and to judge whether or not the stepping motor 5 may be driven.

In step 405, the position of the focusing lens 6 is set in step 40.
This is a step for confirming whether or not it is possible to move to the direction designated by 1, that is, to the near point side. For example, the position of the focusing lens 6 is compared with the limit position on the near point side, and the limit position is reached. If it is possible to move, the next step 407 is selected.

Step 407 is a step of supplying one drive pulse to the motor drive circuit 13 to drive the stepping motor 5 to move the focusing lens 6 to the near point side, and driving the stepping motor 5 for only one step. The lens 6 actually moves to the near point side by an amount corresponding to the driving of the motor 5 for one step. When the step 407 is completed, the step 409 is selected next. On the other hand, step 406 is a step for confirming whether or not the position of the focusing lens 6 can be moved to the far point side instructed in step 402. For example, the position of the focusing lens 6 is set as the far point side limit position. In comparison, if it is possible to move without reaching the limit position, step 408 is selected, and in step 408, contrary to the previous step 407, the focusing lens 6 is driven one step of the stepping motor 5 in the far point direction. When the movement is moved by an amount corresponding to, and the operation is similarly finished, step 409 is selected. In step 409, the position information of the variable power lens 9 is read from the memory unit that stores the number of drive pulses supplied to the stepping motor 14, and the stepping motor 5 is controlled so that the relative speed has the relationship shown in FIG. Is a step of setting the time until the driving pulse for the next one step is supplied, that is, the time measured by the timer confirmed in step 403 or 404.

For example, assuming that the relative time measured by the timer, which is the supply stop time of the drive pulse for obtaining the relative speed 1 in FIG. 2, is 1.5, the relative speed is 0.75, the relative speed is 0.5, and the relative speed is 0.5. In order to obtain the speed of 0.25, it is sufficient to set the relative time measuring time of 4, and it can be said that the step is performed corresponding to such setting operation and the variable power lens position obtained from the memory section described above.

When the setting of the time measured by the timer in step 409 is completed, step 410 is selected next, the operation of measuring the time measured by the timer is started, and then the flow chart returns to the initial step 401 or 402. It will be.

The above operation is performed by C.I. P. By performing the operation in U16, the focusing lens 6 can be moved in the direction set by the manual operation during the power focus operation at a moving speed corresponding to the position of the variable power lens 9.

FIG. 5 is a block diagram showing the basic construction of another embodiment of the focusing lens moving device in the front lens fixed zoom lens according to the present invention. In FIG. is there.

In FIG. 5, reference numeral 19 pre-stores a plurality of driving speed information of the motor 5 for realizing a suitable moving speed of the focusing lens 6 corresponding to the zoom lens position and the focusing lens position, and also the zoom lens. Focusing lens position detecting means 2 for detecting the variable lens position signal output from the position detecting means 2 and the position of the focusing lens 6 and outputting the focusing lens position signal.
The speed setting means outputs the driving speed information corresponding to both the supplied signals by receiving the focusing lens position signal from 0.

That is, in this embodiment, the focusing lens position detecting means 20 is added and the content of the speed setting means 19 is changed as compared with the previously described embodiments.

The operation will be described below centering on the above-mentioned changed portion.

First, regarding the speed setting means 19 with changed contents, as described above, the front lens fixed zoom lens has a feature that the photographing limit on the near point side can be eliminated depending on the setting of the focal length, In order to make full use of such characteristics, even on the wide side, the focusing lens 6 can be moved within the movable range as shown in the focusing characteristic diagram of FIG.

Therefore, for example, when the moving speed of the focusing lens 6 is set slower toward the wide side as in the embodiment described with reference to FIG. Then, a large amount of movement of the focusing lens 6 is required, but there is a disadvantage that it can move only at a slow speed.

In other words, the shooting of a subject at a very short distance is very rare, and considering the normal shooting operation, the moving speed of the focusing lens should be slowed down toward the wide side as in the previous embodiment. Although there is no big problem, in view of making full use of the performance of the front-lens fixed zoom lens, the above-mentioned embodiment is still insufficient.

Therefore, the speed setting means 1 in the embodiment shown in FIG.
In FIG. 9, as the driving speed information of the motor, information according to the relationship between the zoom lens position and the focusing lens position as shown in FIG. 6 is stored in advance.

As a result, when the focusing operation instructing means 1 instructs the focusing operation in an appropriate direction, the motor drive control means 4 causes the sixth operation.
Speed setting means 1 for outputting drive speed information according to the zoom lens position and the focusing lens position having the relationship shown in the figure.
9 and the direction signal from the instructing means 1 controls the motor 5. Of course, the moving speed of the focusing lens 6 is also controlled to the speed corresponding to the above-mentioned variable magnification lens position and the focusing lens position. Will be.

The operation will be described in detail. The set focal length is wide and the position of the focusing lens 6 is 0 to 0.25, that is, about 1 m.
When an in-focus state can be obtained for a distant object, as in the previous embodiment, the relative speed of 0.25 moves at a slower speed than 1 when the set focal length is on the tele side. , The position of the focusing lens 6 gradually approaches 0.25 to 0.5, or 0.5 to 1, ie, the closest distance side, that is, the distance to the subject is 1 m.
When moving to the area where the in-focus state is obtained for the subject from 0.3 m to 0.3 m and from 0.3 m to less than 0.1 m, the moving speed of the focusing lens 6 gradually becomes 0.5, 1 unlike the previous example. A high speed will be set.

Therefore, according to the present invention, the power focus operation having extremely suitable operability can be performed even if the great feature of the front lens fixed zoom lens is utilized.

The above-mentioned setting of the driving speed information can be performed by using a stepping motor as the motor 5 as in the above-described example.
Needless to say, as described with reference to FIG. 4, it can be realized by appropriately setting the time count of the timer that determines the time until the next drive pulse is supplied.

7 (a) and 7 (b) show an example of the focusing operation means 1 in the embodiment shown in FIG. 1 and FIG. 5, and in the embodiment shown in FIG. Another example of the manual operation unit that was the power focus switch 10 is shown, and a focusing operation signal of the focusing lens 6 is output by a rotating operation.

In FIG. 7 (a), 21 is a rotary operation member having a conductor pattern in the shaded portion in the figure, 22 and 23 are contact pieces provided so as to contact the conductor pattern of the rotary operation member 21,
24 and 25 are C.I. P. The resistors for forming the input signal to U are shown respectively.

It is apparent from the drawings that the width of the conductor pattern is doubled between the contact pieces 22 and 23, and the non-conductor pattern portion is also doubled between the contact pieces 22 and 23.

Due to the above-mentioned configuration, as shown by the arrow in FIG. 7 (a), the focusing operation to the near point side is performed in the counterclockwise direction by the clockwise rotation operation of the rotation operation member 21. Assuming that the focus operation to the far point side is instructed by the rotation operation,
C. P. A signal having the relationship shown in FIG. 7 (b) is input to U.

That is, the states of the contact pieces 22 and 23 are such that the high and low levels are output with a half-cycle deviation depending on the relationship between the operation pattern width of the rotary operation member 21 and the contact pieces 22 and 23. Therefore, in terms of decimal numbers, a signal that changes in the increasing direction when the focusing operation is performed on the near point side and decreases when the focusing operation is performed on the far point side is C.I. P. It will be input to U. Further, the input cycle of the above-mentioned signal is the rotation operation member 21.
Will change with the rotation speed of.

As a result, unlike the power focus switch 10 described above, the speed of the manual operation itself is added to the focus direction information, and the C.I.
P. U can be input as one piece of information on the focusing operation. P. The processing in U makes it possible to develop the processing when the speed when the manual speed information is input is processed as the relative speed "1" in FIGS.
If such an expansion is performed, the above-described suitable operation based on the manual operation of the front lens fixed zoom lens is performed with the same feeling as the manual focusing operation of the rear lens fixed zoom lens which has been extremely common in the past. Therefore, it is possible to perform a focusing operation having a property.

As described above, according to the present invention, since the moving speed of the focusing lens at the time of power focus operation is controlled according to the position of the variable power lens, the power focus operation in the front-lens fixed zoom lens is set to the set focus. It has an effect that it can be realized with suitable operability without any difference regardless of the distance. Also, in the present invention, since the moving speed of the focusing lens at the time of power focusing is controlled in addition to the focusing lens position, the focusing lens on the near point side of the front fixed zoom lens is controlled. Even in the case of taking advantage of the great feature of eliminating the problem, there is an effect that a power focus operation with extremely suitable operability can be realized.

Further, in the present invention, when the power focus operation is performed by the rotation operation, the rotation operation speed information is used, so that the above-described feeling is similar to the manual focusing operation in the conventionally known rear lens fixed zoom lens. It also has the effect that it can be expected to develop such effects.

[Brief description of drawings]

FIG. 1 is a block diagram showing the basic structure of an embodiment of a focusing lens moving device for a front fixed zoom lens according to the present invention, and FIG. 2 is stored in advance in the speed setting means 3 in FIG. It is a figure which shows speed information. FIG. 3 is a schematic block diagram showing an embodiment in which a focusing lens moving device for a front fixed zoom lens according to the present invention is constructed by using a microcomputer, and FIG. 4 is a CP in FIG.
It is a flowchart which shows the principal part of operation of U16. FIG. 5 is a block diagram showing a basic configuration of another embodiment of the focusing lens moving device for a front fixed lens according to the present invention,
FIG. 6 is a view showing speed information stored in advance by the speed setting means 19 in FIG. 7 (a) and 7 (b) are a schematic configuration diagram showing an example of the focusing operation means 1 in FIGS. 1, 3, and 5, and a signal state diagram obtained by this configuration, respectively. FIG. 8 is a focusing characteristic diagram showing the relationship between the subject distance and the in-focus lens position that can be obtained in the in-focus state when the variable magnification lens position in a general front fixed zoom lens is used as a parameter. 1 ... Focus operation means, 2 ... Variable magnification lens position detection means,
3 ... Speed setting means, 4 ... Motor drive control means, 5 ...
... Motor, 6 ... Focusing lens, 7 ... Front fixed zoom lens, 8 ... Front lens, 9 ... Variable lens, 10 ...
Power focus switch, 13, 15 ... Motor drive circuit, 14 ... Variable lens drive motor, 16 ... Microcomputer, 17, 18 ... Origin detection switch, 1
9 ... Speed setting means, 20 ... Focusing lens position detecting means, 21 ... Rotating operation member, 22, 23 ... Contact piece.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location G03B 13/36 (56) References JP-A-59-200205 (JP, A) JP-A-56- 162728 (JP, A) JP-A-61-264307 (JP, A)

Claims (5)

[Claims] 1. A motor as a drive source for moving the focusing lens of a front lens fixed zoom lens equipped with a focusing lens for focus adjustment on the image side of a variable power lens, and by manually operating the motor, Focusing operation instructing means for outputting a focusing operation signal for instructing a focusing operation to the near point or far point side of the focusing lens, and a variable magnification lens position signal for detecting the variable magnification lens position and outputting a variable magnification lens position signal. A zoom lens position detecting means and a plurality of driving speed information of the motor preset corresponding to the zoom lens position are stored, and the zoom lens position signal is operated by the focusing operation signal. Accordingly, the speed setting means for receiving the driving speed information corresponding to the received variable magnification lens position signal, the focusing operation signal and the driving speed information output by the speed setting means are supplied. The motor drive control means for driving the motor in the direction and speed based on the focusing operation signal and the drive speed information is provided, and the moving speed of the focusing lens based on the manual operation is changed. A focusing lens moving device in a front lens fixed zoom lens that controls according to the position of a double lens. 2. The focus operation instructing means includes a power focus switch including a manual operation member that is manually operated and two switches that are turned on based on an operation of the manual operation member in the forward and reverse directions. A focusing lens moving device in a front lens fixed zoom lens according to claim 1. 3. The motor according to claim 1, wherein the motor is a stepping motor, and the variable power lens position detecting means is a memory unit for accumulating the number of drive pulses of the stepping motor.
Item 7. A focusing lens moving device in the front-lens fixed zoom lens according to the item. 4. The front lens fixing device according to claim 1, wherein the motor is a stepping motor, and a part of the variable power lens position detecting means, the speed setting means, and the motor drive control means is formed by a microcomputer. Focusing lens moving device in zoom lens. 5. A motor as a drive source for moving the focusing lens of a front lens fixed zoom lens having a focusing lens for focus adjustment closer to the image side than the variable power lens, and by manually operating the motor, Focusing operation instructing means for outputting a focusing operation signal for instructing a focusing operation to the near point or far point side of the focusing lens, and a variable magnification lens position signal for detecting the variable magnification lens position and outputting a variable magnification lens position signal. Magnifying lens position detecting means, focusing lens position detecting means for detecting the focusing lens position and outputting a focusing lens position signal, and presetting corresponding to the variable magnification lens position and the focusing lens position. Further, the plurality of driving speed information of the motor are stored, and the variable magnification lens position signal and the focusing lens position signal are received by being operated by the focusing operation signal, A speed setting means for outputting drive speed information corresponding to a position signal, and the focus operation signal and the drive speed information output by the speed setting means are supplied to drive the motor to the focus operation signal and A motor drive control means for driving in a direction and a speed based on the drive speed information, and controlling the moving speed of the focusing lens based on the operation of the means according to the positions of the variable power lens and the focusing lens. Focusing lens moving device for fixed front zoom lens.