JP3188785B2 - Variable focal length camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a zoom lens or a zoom lens.
Automatically resets the multifocal lens to , for example, the wide end,
Alternatively, the present invention relates to improvement of a variable focal length camera having means Ru is collapsed lens barrel in place.

[0002]

2. Description of the Related Art In recent lens shutter cameras, zooming is driven by an actuator such as a DC motor.
Those with an autofocus function are mainstream.

In this type of zoom camera, the size of the zoom camera has been further reduced as compared with the conventional model, and in order to achieve the purpose of the miniaturization, the photographing optical system has an F-number and a focussing lens when the focal length changes. In this case, the amount of lens extension at the time of the change is usually changed. Therefore, a focal length detecting means for performing the F number correction and the lens extension amount correction is required, and the most common one is that the brush moves on the gray code code pattern in conjunction with the focal length movement. In addition, there is a method of using a variable resistor whose output varies in conjunction with the focal length movement.

However, in such a camera, since there is a mechanical backlash between the photographing optical system and the focal length detecting means, when the zoom drive is stopped, the camera must be biased in one direction. By doing so, this play is removed, and the reproducibility of the correspondence between the focal length and the output of the detection means is improved. However, if the lens barrel is moved by the photographer, this correspondence will be lost, and the focal length corresponding to the output of the focal length detecting means will differ from the actual focal length. It may cause misalignment. Among them, the one having a particularly large influence is a focus shift on the TELE (tele) side having a high focus sensitivity.

[0005] In view of this point, as a precautionary measure when the lens barrel is moved, after a photographer performs an operation with a release switch or a zoom switch, no switch input is made for a certain period of time (normally about 5 minutes). When not performed, the zoom is set to the WIDE (wide) end or the retracted end (collapsed position).
By automatically resetting the camera to a so-called auto power-off function, if the photographer subsequently shoots at a position other than the WIDE end, zooming is always performed.
A configuration in which the backlash of the lens barrel is canceled by the one-sided driving at the time of the stop has been filed by the applicant of the present invention (Japanese Utility Model Laid-Open No. 3-60331).

FIG. 5 shows a simple circuit configuration of a zoom camera having an auto power off function.

In FIG. 5, reference numeral 51 denotes a sequence controller for controlling the sequence of the entire camera; 52, a distance measuring unit for measuring a distance to a subject for performing autofocus; 53, a photometry for measuring subject brightness for performing automatic exposure; A circuit, a photographing lens, a lens driving unit for driving the photographing lens during focusing, a shutter, a shutter driving circuit for driving the shutter, and a focal length of the photographing lens A focal length detecting means 59 for performing zooming; a zoom motor 59 for performing zooming;
Is a zoom motor drive circuit for driving the zoom lens.

[0008] 61 is a release switch, 62 is TELE
Switch 63, a WIDE switch; 64, a main switch which is in a release standby state (main ON) when ON; and a release prohibited state (main OFF) when OFF; 6
Reference numeral 5 denotes a battery serving as a power supply for the camera.

Next, a configuration example of the focal length detecting means 58 will be described with reference to FIG. Here, it is assumed that a variable resistor whose output varies in conjunction with the movement of the focal length is used as the focal length detecting means 58.

In FIG. 6, reference numeral 71 denotes a variable resistor.
Both ends are connected to a constant voltage VC (= 2.5 V) and GND, and the movable contact piece moves in conjunction with zooming, and moves to the VC side during the TELE zoom and to the GND side during the WIDE zoom. Reference numeral 72 denotes an A / D converter for A / D converting the potential V _OUT of the movable contact piece of the variable resistor 71.

In the above configuration, the potential V _OUT of the movable contact of the variable resistor 71 is A / D converted by the A / D converter 72,
By outputting this to the system controller 51, the focal length of the photographing lens 54 can be detected by the system controller 51.

The detection result is divided into a plurality of zones in the sequence controller 51 so that arithmetic processing can be easily performed. FIG. 7 shows an example of the correspondence between the potential (output) V _OUT and the focal length corresponding to the 13 zones.

In the example of FIG. 7, the focal length of the camera is "35".
１０５105 mm ”, and each zone is TE
Numbers “1 to 13” called “zoom positions” are assigned in order from the LE end.

Next, the operation relating to the automatic power-off function of the camera in the above configuration will be described with reference to the flowchart of FIG.

First, in the initial state, the camera is in a switch input standby state in which the main switch 64 is turned on, and enters a low current consumption mode (such as reducing the clock frequency of the microcomputer) to reduce the consumption of the battery 65. It is assumed that

In this state, the release switch 61
If there is a switch input such as N, the camera releases the low current consumption mode and performs an operation according to the switch input (steps 401 → 402 → 403). For example, if the release switch 61 is ON, the release operation is performed (at this time, the focal length is detected by the focal length detecting means 58, and the calculation of the focusing position and the calculation relating to the automatic exposure are performed according to the zoom position).

After the above operation is completed, an auto power-off timer (for example, a 5-minute timer) starts immediately (step 404), and the camera waits until the timer ends. Then, if there is any switch input during the WAIT, an operation corresponding to the switch input is performed (step 4).
04 → 405 → 403), and then the auto power off timer is restarted from the first count (reset value) (step 404). When there is no switch input while the auto power-off timer is counting, when the timer expires, the camera automatically zooms the lens barrel to the WIDE end (steps 404 → 405 → 406 → 40).
7) Then, return to the low current consumption mode, that is, return to the initial state (step 408).

[0018]

However, in the above conventional example, the auto power off timer always starts after a switch input such as a release operation, and
Since the number of times of automatic zooming to the WIDE end is large, the battery is quickly consumed.

In the auto power-off operation, the camera starts moving without touching anything, giving the photographer a sense of incongruity. In addition, the lens barrel is moved by the photographer, and defocusing during focusing may occur. If it does,
The effect on the actual picture is that the focus sensitivity is high.
Only on the ELE side, there is almost no effect when the lens barrel is near the WIDE end.
Performing automatic zooming to the DE end is useless.

(Object of the Invention) A first object of the present invention is to provide a variable focal length camera capable of reducing power consumption of a power battery and a sense of discomfort given to a photographer without performing useless auto power-off operation. That is.

A second object of the present invention is to provide a variable focal length camera capable of saving power of a power supply battery.

[0022]

In order to achieve the first object, the present invention according to claim 1 determines whether or not a switch input has been performed within a predetermined time, and determines whether or not the switch input has been performed. If it is determined that there is no image, move the zoom lens or multifocal lens in the direction of the wide focal length.
A variable focal length camera having automatic resetting means for resetting the lens to a predetermined position , wherein the focal length of the lens is within a predetermined range wider than a predetermined focal length.
When the distance is set to the tele side from the predetermined position, the variable focal length camera has control means for inhibiting the operation of the automatic reset means.

[0023] In order to achieve the first object, the present invention according to claim 2 determines whether a switch input has been performed within a predetermined time and determines that no switch input has been performed. In the case where the variable focal length camera has automatic reset means for retracting the lens barrel holding the zoom lens or multifocal lens to a predetermined position ,
The focal length of the lens is wider than a predetermined focal length
The camera is a variable focal length camera having a control means for prohibiting the operation of the automatic reset means when it is within a predetermined range on the side and is set on the tele side from the predetermined position. . In order to achieve the second object, the present invention according to claim 3 determines whether or not a switch input has been performed within a predetermined time, and determines that no switch input has been performed. Move the zoom lens or multifocal lens in the direction of the focal length on the wide side, and
Reset in position, or, in the variable focal length camera having an automatic resetting means for collapsing the lens barrel that holds the lens in a predetermined position, a temperature detecting means for detecting the temperature, detected by the temperature detecting means When the temperature is below a predetermined temperature, the variable focal length camera has a control means for prohibiting the operation of the automatic reset means.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a block diagram showing a circuit configuration of a zoom camera according to a first embodiment of the present invention.
Are the same as 51 to 65 in FIG. 6, and the details are omitted here. The focal length detecting means 8 has the configuration shown in FIG. 6. As shown in FIG. 7, the detection result here is divided into a plurality of zones (13 zones) in the sequence controller 1 so that arithmetic processing can be easily performed. ) And are associated with each other.

FIG. 2 is a flowchart showing the operation relating to the auto power-off function of the zoom camera having the above-described configuration, and the operation will be described below.

In the initial state, the camera is set to the main switch 1
4 is turned on to be in a switch input standby state, and the apparatus is in a low current consumption mode (such as reducing the clock frequency of the microcomputer) to reduce the consumption of the battery 15.

Here, when there is a switch input such as ON of the release switch 11, the camera releases the low current consumption mode and performs an operation according to the switch input (step 10).
1 → 102 → 103). For example, the release switch 11
, The release operation is performed.

After the above operation is completed, the focal length is detected by the focal length detecting means 8 (step 104), and the result is "zoom position>10", that is, number 1
7, 12, 13 (see FIG. 7) (focal length 4
(Less than 7 mm), the zoom lens in the photographing lens 4 is located near the WIDE end, so it is determined that there is no need for the auto power-off operation.
That is, the process returns to the initial state (step 105 → 110).

On the other hand, the focal length detected by the focal length detecting means 8 is “zoom position ≦ 10”, that is, within 10 zones of numbers 1 to 10 (focal length 47 mm or more).
If so, the auto power-off timer is started and WAIT is performed until the timer ends. And this WAIT
If there is any switch input during this time, the operation corresponding to the switch input is performed, and then the auto power-off timer is started again from the initial count (reset value) (steps 106 → 107 → 103 → 104 →). 10
5 → 106 or step 106 → 107 → 108 →
107 → 103 → 104 → 105 → 106).

If there is no switch input while the auto power-off timer is counting and the timer ends,
The lens barrel (zoom lens) is automatically zoomed to the WIDE end via the zoom motor drive circuit 10 and the zoom motor 9, and then enters the low current consumption mode, that is, returns to the initial state (step 105 → 106 → 107 → 108
→ 109 → 110).

(Second Embodiment) In the first embodiment,
If there is no switch input while the auto power-off timer is counting and the timer ends, the lens barrel is moved to WID.
Although zooming is performed to the E end, the lens barrel may be reset to the retracted position at this time. Hereinafter, this type of camera is referred to as a second embodiment of the present invention.

FIG. 3 is a flow chart showing the operation relating to the automatic power-off function of the camera in the second embodiment, which will be described below. The circuit configuration and the like are the same as those in the first embodiment except that a collapsible unit for collapsing the lens barrel is added.

In the initial state, the camera is set to the main switch 1
4 is turned on to be in a switch input standby state, and the apparatus is in a low current consumption mode (such as reducing the clock frequency of the microcomputer) to reduce the consumption of the battery 15.

Here, when there is a switch input such as ON of the release switch 11, the camera releases the low current consumption mode and performs an operation according to the switch input (step 20).
1 → 202 → 203). For example, the release switch 11
, The release operation is performed.

After the above operation is completed, the focal length is detected by the focal length detecting means 8 (step 204), and the result is "zoom position>10", that is, number 1
7, 12, 13 (see FIG. 7) (focal length 4
(Less than 7 mm), the zoom lens in the photographing lens 4 is located near the WIDE end, so it is determined that there is no need for the auto power-off operation.
That is, the process returns to the initial state (step 205 → 210).

On the other hand, the focal length detected by the focal length detecting means 8 is "zoom position≤10", that is, within 10 zones of numbers 1 to 10 (focal length 47 mm or more).
If so, the auto power-off timer is started and WAIT is performed until the timer ends. And this WAIT
If there is any switch input during this time, the operation corresponding to the switch input is performed, and then the auto power-off timer is restarted from the initial count number (reset value) (steps 206 → 207 → 203 → 204 →). 20
5 → 206 or Step 206 → 207 → 208 →
207 → 203 → 204 → 205 → 206).

If there is no switch input while the auto power off timer is counting and the timer ends,
The lens barrel is automatically driven to the retracted position via retractable means (not shown), and then enters the low current consumption mode, that is, returns to the initial state (steps 205 → 206 → 207 → 2).
08 → 209 → 210).

(Third Embodiment) The output characteristics of a lithium battery or a manganese battery used as a power source for a camera are poor at low temperatures. For this reason, if the temperature around the camera is determined to be low, if the low power consumption mode is immediately entered without performing the auto power-off operation, power saving measures at low temperatures can be taken. Hereinafter, this type of camera will be referred to as a third embodiment.

FIG. 4 is a flowchart showing the operation relating to the automatic power-off function of the camera in the third embodiment, and the operation will be described below. Except for the addition of a temperature sensor for detecting the temperature around the camera, the circuit configuration and the like are the same as in the first embodiment, and a description thereof will be omitted.

In the initial state, the camera is set to the main switch 1
4 is turned on to be in a switch input standby state, and the apparatus is in a low current consumption mode (such as reducing the clock frequency of the microcomputer) to reduce the consumption of the battery 15.

Here, when there is a switch input such as ON of the release switch 11, the camera releases the low current consumption mode and performs an operation according to the switch input (step 30).
1 → 302 → 303). For example, the release switch 11
, The release operation is performed.

After the above operation is completed, the temperature TEMP around the camera obtained based on the output of a temperature sensor (not shown) is detected, and if this result is "TEMP ≦ 0 ° C." Immediately returns to the low current consumption mode, that is, returns to the initial state (step 304 → 309).

On the other hand, if the temperature around the camera obtained based on the output of a temperature sensor (not shown) is “TEMP> 0 ° C.”, the auto power-off timer is started and the wait is performed until the timer ends. Then, if there is any switch input during the WAIT, an operation corresponding to the switch input is performed, and then the auto power-off timer is restarted from the first count (reset value) (steps 305 → 306 →). 303 → 304 → 305,
Or, Steps 305 → 306 → 307 → 308 → 30
7 → 303 → 304 → 305).

If there is no switch input while the auto power off timer is counting and the timer ends,
A zoom reset operation is performed to enter the low current consumption mode, that is, return to the initial state (steps 305 → 306 →).
307 → 308 → 309).

In this embodiment, as in the first or second embodiment, the focal length is detected by the focal length detecting means 8 and the result is "zoom position>10".
In other words, when the zoom lens is located near the TELE, the camera can be zoomed automatically to the WIDE end or the lens barrel can be retracted, and the camera can be used more easily by having an auto power off operation. Becomes possible.

According to the first and second embodiments,
Auto power only when the lens barrel is near TELE
-Since the auto-off timer is started and the auto power-off operation is performed simultaneously with the end of the timer, the battery consumption can be reduced and the WIDE end which is not affected by the focus shift even when the lens barrel shifts. When there is a lens barrel in the vicinity, the auto power-off operation is not performed, so that there is no useless operation and the sense of discomfort given to the photographer can be reduced.

According to the third embodiment, when the ambient temperature of the camera is “TEMP ≦ ° C.”, the automatic
Since the low power consumption mode is immediately set without starting the power-off timer , power saving can be achieved, and further power saving can be realized by adding the above-mentioned auto power-off function.

[0049]

As described above, according to the present invention, it is possible to provide a variable focal length camera capable of reducing power consumption of a power battery and a sense of discomfort given to a photographer without performing useless auto power-off operation. Things.

Further , according to the present invention, the power saving of the power battery is performed.
Variable focal length camera that can achieve
It can be.

[0051]

[0052]

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a zoom camera according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of a main part of the camera of FIG.

FIG. 3 is a flowchart illustrating an operation of a zoom camera according to a second embodiment of the present invention.

FIG. 4 is a flowchart illustrating an operation of a zoom camera according to a third embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional zoom camera.

FIG. 6 is a circuit diagram illustrating a configuration example of a focal length detection unit in FIG. 5;

FIG. 7 is a diagram showing a relationship between a potential V _OUT , a focal length, and a zoom position in FIG.

FIG. 8 is a flowchart showing the operation of a conventional zoom camera.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sequence controller 4 Shooting lens 8 Focal length detecting means 9 Zoom motor 10 Zoom motor drive circuit 11 Release switch

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G03B 17/04 G02B 7/08

Claims (3)

(57) [Claims] 1. A zoom lens or a multifocal lens is moved in a direction of a wide focal length when it is determined whether or not a switch input is performed within a predetermined time, and when it is determined that no switch input is performed. Position the lens
A variable focal length camera having automatic resetting means for resetting the lens to a predetermined focal length.
Within a predetermined range on the wide side of the distance,
A variable focal length camera having control means for prohibiting the operation of the automatic reset means when the telephoto side is set to a position closer to the telephoto side than the fixed position . 2. A lens barrel for holding a zoom lens or a multi-focal lens is moved to a predetermined position when it is determined whether or not a switch input has been performed within a predetermined time. In the variable focal length camera having automatic resetting means for retracting, the focal length of the lens is within a predetermined range on the wide side of the predetermined focal length.
And a control unit for prohibiting the operation of the automatic reset unit when the camera is set on the tele side from the predetermined position . 3. It is determined whether or not a switch input has been performed within a predetermined time, and if it is determined that no switch input has been performed, the zoom lens or the multifocal lens is moved in the direction of the focal length on the wide side. Position the lens
To reset, or in a variable focal length camera having an automatic resetting means for collapsing the lens barrel that holds the lens in a predetermined position, a temperature detecting means for detecting the temperature, detected by the temperature detecting means temperature Control means for prohibiting the operation of the automatic reset means when the temperature is equal to or lower than a predetermined temperature.