Abstract:
An optical apparatus having an image-forming optical system comprising a movable lens, comprises a lens drive mechanism for moving the movable lens, a focus adjusting device for automatically adjusting an imaging position by moving the movable lens or another optical element, based on detection of a focus detecting-device, a detecting device for detecting a temperature change or a humidity change, and a control device for actuating the lens drive mechanism upon stop of operation of the focus adjusting device, based on detection in the detecting device, to move the movable lens for correction.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an optical apparatus having a moving lens.  
           [0003]    2. Related Background Art  
           [0004]    In the field of the optical apparatus including cameras, compactification of photographing optical system and reduction of image size of solid state image sensing device has quickly been advancing these years. In addition, plastic materials are often used as optical materials for making the photographing optical system. Use of plastic materials has such features that a lens can be molded readily by mold, that arbitrariness of shape thereof is high, and that the cost merit is higher than that of glass materials. Because of such features, lenses made of plastic materials are frequently used in a viewfinder system, in an infrared active autofocus unit, in parts of the photographing optical system, and so on.  
           [0005]    The plastic materials show greater changes of physical properties against environmental changes than inorganic glass materials. For example, PMMA of a plastic material has a large coefficient of linear expansion: 67.9×10 −6 /° C. typical, whereas LaK 14 (available from OHARA) of an inorganic glass has a coefficient of linear expansion one order of magnitude smaller than it: 57×10 −7 /° C. As for changes of refractive index against temperature changes, PMMA shows 1.0 to 1.2×10 −4 /° C. typical, whereas the above LaK 14 shows 3.9 to 4.4×10 −6 /° C. at the D-line two orders of magnitude smaller than those.  
           [0006]    As explained above, the plastic materials show greater changes of various optical constants (the refractive index, the shape, etc.) against temperature changes than the inorganic glass materials. For example, the lenses made of the plastic materials, so-called plastic lenses, have greater changes of focal length against temperature changes than the lenses made of the inorganic glass materials.  
           [0007]    Further, the plastic materials have larger water absorption rates than the inorganic glass materials. Therefore, the various optical constants of the plastic lenses change greater against humidity changes, similarly as against temperature changes, than the lenses made of the inorganic glass materials.  
           [0008]    The effects as discussed previously can be attained by using the plastic lens in parts of the optical system. However, it raises the problem that the optical properties including the focal length change greater against environmental changes, particularly against temperature changes or against humidity changes, than in the case of use of the lenses made of the inorganic glass materials.  
           [0009]    The recent optical apparatus is compactified by compactifying the photographing optical system, compactifying the solid state image sensing device, and increasing the density of various elements. This raises the problem that the temperature changes, moisture changes, or the like increase an effect of deviation of the image plane of the optical system used in the optical apparatus with respect to the intended image plane. It is, therefore, a significant issue how to effectively correct the deviation of the imaging position due to such environmental changes.  
           [0010]    Further, many recent optical devices are provided with an autofocusing function (AF function) for automatically detecting the in-focus position of optical system. During photography with operation of the AF function, for example, if any obstacle such as a car or a pedestrian goes between the optical apparatus and the object, the AF means will make the optical system in focus with the obstacle. This will result in failing to image the target object on the image plane. Thus, there was the problem that photography must be made under stop of the AF function in order to avoid it. Stop of the operation of the AF function during photography is not preferred, because the position of the image plane changes greatly with the environmental changes as discussed previously in the case of the optical apparatus using the optical system including the plastic lens.  
         SUMMARY OF THE INVENTION  
         [0011]    One aspect of the invention is to provide an optical apparatus arranged to detect temperature or/and humidity and to effect correction of position based on a detection result thereof when a moving lens is at a stop of operation.  
           [0012]    The other aspects will become apparent from the detailed description that follows. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a schematic drawing to show the principal part of Embodiment  1  according to the present invention;  
         [0014]    [0014]FIG. 2 is a flowchart to show the operation of Embodiment 1 according to the present invention;  
         [0015]    [0015]FIG. 3 is a schematic drawing to show the principal part of Embodiment 2 according to the present invention;  
         [0016]    [0016]FIG. 4 is a flowchart to show the operation of Embodiment 2 according to the present invention;  
         [0017]    [0017]FIG. 5 is a schematic drawing to show the principal part of Embodiment 3 according to the present invention;  
         [0018]    [0018]FIG. 6 is a flowchart to show the operation of Embodiment 3 according to the present invention;  
         [0019]    [0019]FIG. 7 is a flowchart to show the operation of the optical apparatus as the fourth embodiment;  
         [0020]    [0020]FIG. 8 is a flowchart to show the operation of the optical apparatus as the fifth embodiment;  
         [0021]    [0021]FIG. 9 is a flowchart to show the operation of the optical apparatus as the sixth embodiment;  
         [0022]    [0022]FIG. 10 is a cross-sectional view of the principal part to show the seventh embodiment of the optical apparatus according to the present invention;  
         [0023]    [0023]FIG. 11 is a flowchart to show the operation of the optical apparatus shown in FIG. 10;  
         [0024]    [0024]FIG. 12 is a cross-sectional view of the principal part to show the eighth embodiment of the optical apparatus according to the present invention;  
         [0025]    [0025]FIG. 13 is a flowchart to show the operation of the optical apparatus shown in FIG. 12;  
         [0026]    [0026]FIG. 14 is a cross-sectional view of the principal part to show the ninth embodiment of the optical apparatus according to the present invention; and  
         [0027]    [0027]FIG. 15 is a flowchart to show the operation of the optical apparatus shown in FIG. 14. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]    [0028]FIG. 1 is a block diagram to show the principal part of Embodiment 1 of the present invention. In the figure numeral  1  denotes an optical system (a photographing system), which is a rear focus zoom lens (hereinafter referred to as “RFZ” lens) of the so-called four-unit configuration composed of four lens units.  
         [0029]    The RFZ lens  1  is comprised of a first lens unit (hereinafter referred to as “front lens”)  101  being a fixed lens unit, a second lens unit (hereinafter referred to as “variator”)  102  with a magnification change or zoom function being a moving lens unit, a third lens unit (hereinafter referred to as “afocal”)  103  being a fixed lens unit, and a fourth lens unit (hereinafter referred to as “RR”)  104  being a moving lens unit and having a function as a compensator for compensating for variations in image plane due to focus and magnification changes.  
         [0030]    Practically, the above lens units are composed of a plurality of lenses. For example, in the present embodiment, the front lens  101  is comprised of three lenses, the variator  102  of three lenses, the afocal  103  of a single lens, and the RR (rear relay)  104  of two lenses, thus constituting the four-unit and 9-lens configuration.  
         [0031]    In the present embodiment, a plastic lens made of a plastic material is used in at least one lens unit out of the lens units. The material for the plastic lens may be selected from acrylic based plastics, polyolefin based plastics, polycarbonate, and so on.  
         [0032]    There is no specific limitation on where the plastic lens should be used in the lens units in the present embodiment, and there are some cases without using the plastic lens in the lens units at all.  
         [0033]    Numeral  2  designates a photoelectric conversion element (image pickup means) such as a CCD, and  3  an aperture member for adjusting a quantity of light incident to the photoelectric conversion element  2 . Numeral  6  is an aperture driver, which is comprised of an iG meter or a STEP motor or the like and which changes the area of the aperture of the aperture member  3  by driving aperture wings in the aperture member  3  nearly perpendicularly to the optic axis, based on a signal from a controller  7 , so as to keep the quantity of light incident to the photoelectric conversion element  2  constant. Numeral  4  designates an aperture position detector, which detects the size of the aperture of the aperture member  3 . Numeral  5  represents a detection circuit for converting a detection signal from the aperture position detector  4  to a signal processable by the controller  7  and outputting the obtained signal.  
         [0034]    Numerals  8 ,  9  are driving units such as step motors for driving the moving lens units  102 ,  104 , respectively, and numerals  10 ,  11  are drivers for driving the driving units  8 ,  9 , respectively. Numeral  12  stands for a temperature detector such as a thermistor or thermally sensitive resistor, and numeral  13  for a detection circuit for detecting an output from the temperature detector  12  and outputting a signal to the controller  7 . For detecting humidity, the element  12  serves as a humidity detector such as an electrostatic capacity type sensor or a thermistor.  
         [0035]    Numeral  14  denotes an amplifier for amplifying an output from the photoelectric conversion element  2 ,  15  a process circuit for converting a signal from the amplifier  14  to a signal such as an NTSC video signal,  16  an autofocusing device for generating a signal for autofocusing (hereinafter referred to as AF) from a signal output from the process circuit  15  and effecting the AF operation, and  17  an AF controller comprised of a switch for turning the AF operation of AF device  16  on or off. An example of the method of AF is the so-called hill climbing method, for example, the method as proposed in U.S. Pat. No. 4,804,831.  
         [0036]    In the present embodiment, the controller  7  obtains a drive amount of RR  104 , based on an in-focus signal from the AF device  16 , and supplies it to the driver  11 . Then the driver  11  drives the motor  9 , based on the in-focus signal, to move the RR  104 , thereby effecting AF.  
         [0037]    The present embodiment employs the plastic lens in at least one lens unit. Therefore, a temperature change or a humidity change around the plastic lens due to an environmental change will change the shape of the plastic lens as described previously and change the refractive index thereof because of a large temperature coefficient of refractive index of the material, thereby greatly changing the focal length. The following description mainly concerns the temperature changes as the environmental changes, but it is noted that the same can be applied to the humidity changes.  
         [0038]    The temperature changes will change focal lengths of the respective lens units, which will also change the total focal length of the lens system  1 . As a result, the image plane will deviate from the image plane at reference temperature (which is set at 20° C. in the present embodiment). Namely, defocus occurs.  
         [0039]    Accordingly, when photography is carried out in fixed focus without action of the AF function, defocus occurs with changes of temperature, which is a problem very undesirable for the optical apparatus. In order to solve this problem, the present embodiment is thus arranged to detect the temperature and correct the focus in accordance with a temperature change.  
         [0040]    Specifically, even if an environmental change (a temperature change or a humidity change) occurs while the AF controller  17  stops the operation of the AF device  16  (or stops the drive unit  9 ), the controller  7  drives the motor  9  through the driver  11 , based on the output signal from the detection circuit  13 , to move the RR (moving lens)  104 . This effects correction for the position of the image plane, thereby achieving a good image.  
         [0041]    The controller  7  has data of focus moving amount per unit temperature (temperature correction coefficient data) Trr. Then, the focus moving amount data Trr is multiplied by a temperature change amount ΔT to obtain a focus moving amount or correction amount data (temperature-corrected position data) Prr. 
         Δ T =|detected temperature−reference temperature| 
         
       Prr=ΔT×Trr 
     
         [0042]    Here, the temperature correction coefficient data is defined as a function of position of the moving lens unit for magnification change. The above equations can be applied to humidity as they are.  
         [0043]    The operation of the present embodiment is next explained using the flowchart of FIG. 2.  
         [0044]    In FIG. 2, it is determined at step  201  whether the AF function of the AF device  16  is on or off. If it is on then an AF off flag is cleared at step  202  and the flow returns to step  201 . If it is off then it is determined at step  203  whether the AF off flag is cleared. If cleared, the detection circuit  13  reads a temperature detection output at step  204 , the detected temperature is set as a reference temperature at step  205 , and the AF off flag is set at step  206 . If the AF off flag is set at step  203 , the detection circuit  13  reads a temperature detection output at step  207  and it is determined at step  208  whether the detected temperature is equal to the reference temperature. If they are equal, the flow returns to step  201 . If they are different, the temperature change amount ΔT and correction amount Prr are calculated to perform the temperature compensation control for driving the RR  104  at step  209 , and the temperature detected at step  210  is set as a reference temperature. Then the flow returns to step  201 .  
         [0045]    As described above, the present embodiment is arranged to obtain good image information in such a way that when the operation of the AF device  16  is stopped and if there is an environmental change, the controller  7  drives RR  104 , based on the signal from the detection circuit  13 , thereby maintaining the in-focus state.  
         [0046]    [0046]FIG. 3 and FIG. 4 are a schematic drawing of the principal part and the flowchart of the operation of Embodiment 2 according to the present invention. In the drawing the same elements as those shown in Embodiment 1 of FIG. 1 are denoted by the same reference numerals.  
         [0047]    In the drawing, numerals  18 ,  19  denote switches for manual focus control device (hereinafter referred to as MFD). With either switch kept in the on state, the switch  18  drives the focus lens  104  to the nearest extreme or the switch  19  drives it to the infinite extreme. The present embodiment is based on the premise of recognition that the focus position at the end of the MFD operation is the in-focus position and that the temperature at the end of the operation is the reference temperature. Therefore, the present embodiment is different from Embodiment 1 only in that when the manual focus control is carried out, the temperature at the end of operation is stored and, based thereon, a temperature change is detected and correction is made, and the other arrangement of the present embodiment is the same as that of Embodiment 1.  
         [0048]    The operation of the present embodiment is next explained using the flowchart of FIG. 4.  
         [0049]    It is determined at step  401  whether the MFD switch  18  or  19  is on or off. If either one is on, an MFD off flag is cleared at step  402  and then the flow returns to step  401 . If they are off, it is determined at step  403  whether the MFD off flag is cleared. If cleared, the temperature detection output is read at step  404 , the detected temperature is set as a reference temperature at step  405 , and the MFD off flag is set at step  406 . If the MFD off flag is set at step  403 , the temperature detection output is read at step  407  and it is determined at step  408  whether the detected temperature is equal to the reference temperature. If they are equal, the flow returns to step  401 . If they are different, the temperature change amount ΔT and correction amount Prr are calculated to perform the temperature compensation control for driving RR  104  at step  409 , the temperature detected is set as a reference temperature at step  410 , and then the flow returns to step  401 . In the MFD, any means that can detect the operation thereof may be employed without having to be limited to on/off of switch as described.  
         [0050]    [0050]FIG. 5 and FIG. 6 are a schematic drawing of the principal part and a flowchart of the operation of Embodiment 3 according to the present invention. In the drawing the same elements as those shown in Embodiment 1 of FIG. 1 are denoted by the same reference numerals.  
         [0051]    In the drawing, numerals  20 ,  21  designate zoom switches. With either switch kept in the on state, the zoom switch  20  drives the variator lens  103  to the telephoto extreme or the zoom switch  21  to the wide angle extreme. The present embodiment is different from Embodiment 1 in that when the view angle is changed by the zoom operation, it is determined that an idle state is broken, the temperature at the end of zoom operation is stored, a temperature change is detected as assuming that the idle state is again established after that, and correction is made based thereon, and the other arrangement of the present embodiment is the same as that of Embodiment 1.  
         [0052]    The operation of the present embodiment is next described using the flowchart of FIG. 6.  
         [0053]    It is determined at step  601  whether the zoom switch  20  or  21  is on or off. If either one is on, a zoom off flag is cleared at step  602  and the flow returns to step  601 . If they are off, it is determined at step  603  whether the zoom off flag is cleared. If cleared, the temperature detection output is read at step  604 , the detected temperature is set as a reference temperature at step  605 , and the zoom off flag is set at step  606 . If the zoom off flag is set at step  603 , the temperature detection output is read at step  607  and it is determined at step  608  whether the detected temperature is equal to the reference temperature. If they are equal, the flow returns to step  601 . If they are different, the temperature change amount ΔT and correction amount Prr are calculated to perform the temperature compensation control for driving RR  104  at step  609 , the detected temperature is set as a reference temperature at step  610 , and then the flow returns to step  601 . In the present embodiment, the detection of zoom operation may be done by any means that can detect the operation without having to be limited to on/off of switch as described.  
         [0054]    As explained above, employment of the configuration of the present embodiment permits good images without defocus to be obtained even with temperature changes during zooming, during the operation of the AF function, or during stop of the AF function, or even with occurrence of deviation from the reference temperature though the temperature has been kept constant.  
         [0055]    The present embodiment uses a single temperature detector  12 , but it may be modified to use plural detectors, which can achieve better effects.  
         [0056]    The present embodiment was described as an example where the environmental changes were the temperature changes, but with humidity changes or pressure changes as environmental changes, the configuration as described above can handle such changes in the same manner as long as the apparatus is provided with a means for detecting such changes. For example, the apparatus may be provided with either a temperature detector or a humidity detector, or the apparatus may be provided with the both detectors and arranged to correct defocus due to the temperature changes and humidity changes.  
         [0057]    The embodiments as described above can achieve the optical apparatus suitable for video cameras, silver-salt cameras, electronic still cameras, and so on in such an arrangement that while photography is made with operating the autofocusing function using the optical system (photographing lens) having a moving lens unit to move on the optical axis in order to achieve focus or magnification change, even if there is an environmental change upon stop of the operation of the autofocusing function for some reason, for example, if there is a temperature change or a humidity change, deviation of the image plane can be corrected for by properly setting movement of the moving lens unit, when necessary, according to the environmental change, whereby high optical performance can be maintained.  
         [0058]    The fourth embodiment is next described using FIG. 7.  
         [0059]    Since the structure itself of the optical apparatus of the fourth embodiment is the same as in FIG. 1, description of the components is omitted herein.  
         [0060]    In the fourth embodiment the controller  7  obtains a drive amount of RR  104 , based on the in-focus signal from the AF device  16 , and outputs a drive control signal to the driver  11 . Then the driver  11  drives the lens drive unit  9 , based on the drive control signal from the controller  7 , to move RR  104  along the direction of the optical axis, thereby effecting AF of RR  104 .  
         [0061]    Since the optical system  1  of the fourth embodiment employs the plastic lens in at least one lens unit, as discussed previously, occurrence of a temperature change or a humidity change around the plastic lens due to an environmental change will change the shape of the plastic lens and change the refractive index because of the large temperature coefficient of refractive index of the material, as described previously, so as to greatly change the focal length, which inevitably changes the total focal length of the optical system  1 . Because of it, if photography is carried out in fixed focus without action of the AF function, the position of the image plane will deviate from that at the reference temperature (for example, 20° C.) with temperature changes, which will cause so-called defocus and which will degrade the optical performance as an optical apparatus for clear photography of object.  
         [0062]    In order to cancel the defocus occurring with environmental changes during photography under stop of the AF function and in fixed focus, the fourth embodiment is arranged so that when the AF controller  17  stops (or turns off) the operation (function) of the AF device  16 , the detector  12  detects the ambient temperature of the optical system  1 , the temperature is stored, and thereafter, if the ambient temperature changes, the function of the AF device  16  is utilized to move the RR  104  to the in-focus position, thereby correcting deviation in the position of the image plane of the optical system due to the change of the ambient temperature.  
         [0063]    The following description will concern the deviation of the image plane (defocus) and solving methods of the deviation of the image plane, mainly focusing on the temperature changes as environment changes, but the same solving methods can be applied to the cases where defocus occurs from problems due to the humidity changes.  
         [0064]    Specifically describing the correction for variations in the position of the image plane of the optical system in the fourth embodiment, the controller  7  sets the detected temperature obtained from the detector  12  as a reference temperature when the AF controller  17  stops (or turns off) the operation (function) of the AF device  16 , and a determining circuit not shown determines whether the detected temperature obtained from the above detector  12  after setting of the reference temperature has a change. If the later detected temperature as a determination object shows a change, the AF device  16  is functioned to control the drive of the lens drive unit  9 , based on the in-focus signal of the AF device  16 , to move RR  104  to the in-focus position, thereby correcting variation in the position of the image plane of the optical system due to the change of ambient temperature. This can correct the variation in the position of the image plane of the optical system due to the change of ambient temperature, thereby obtaining good image information.  
         [0065]    The operation of the fourth embodiment is next explained using the flowchart of FIG. 7. It is determined at step  1201  whether the AF function of the AF device  16  is on or off. If it is on, the AF off flag is cleared at step  1202  and then the flow returns to step  1201 . If the AF function is off, it is determined at step  1203  whether the AF off flag is cleared. If it is cleared, the detector  12  reads a temperature detection value at step  1204 , the temperature detection value (detected temperature) is set as a reference temperature at step  1205 , and the AF off flag is set at step  1206 .  
         [0066]    If at step  1203  the AF off flag is not cleared, i.e., if it is set, the detector  12  reads a temperature detection value at step  1207  and it is determined at step  1208  whether the temperature detection value (detected temperature) is equal to the reference temperature. If they are equal, the flow returns to step  1201 . If they are different, the flow goes to step  1209  to perform temperature compensated AF control to move RR  104  to the in-focus position by the AF function, the reference temperature is updated at step  1210  so that the above detected temperature which was the determination object with respect to the above reference temperature is set as a new reference temperature, and then the flow returns to step  1201 .  
         [0067]    As described above, the fourth embodiment is arranged in such a manner that when the AF controller  17  stops the operation of the AF device  16 , the detected temperature obtained from the detector  12  is set as a reference temperature and that if the detected temperature obtained from the detector  12  varies from the reference temperature, the controller performs the temperature compensated AF control for moving the RR  104  to the in-focus position utilizing the function of the AF device  16 , thereby achieving good image information.  
         [0068]    The optical apparatus of the fifth embodiment shown in FIG. 8 is provided with the manual focus adjusting devices  18 ,  19  for manually driving the lens drive unit  9  through the controller  7  to move RR  104 , thereby effecting manual focusing operation, and thus has the same arrangement as the optical apparatus of the second embodiment. Since the configuration of the present embodiment is the same as that of FIG. 3, description of the individual components is omitted herein.  
         [0069]    The fifth embodiment is based on the premise that the focus position at the end of the MFD operation is the in-focus position and that the ambient temperature at the end of the operation of RR  104  is set as a reference temperature. Namely, when the manual focus adjustment is carried out during stop of the operation of the AF device  16  by the AF controller  17 , the ambient temperature is stored during stop of the operation of RR  104  or at the end of the operation of RR  104 . When the ambient temperature of the optical system  1  changes after that, the function of the AF device  16  is utilized to move RR  104  to the in-focus position, thereby correcting variation in the position of the image plane of the optical system due to the change of environment information.  
         [0070]    Specifically, the controller  7  sets the detected temperature obtained from the detector  12  as a reference temperature during stop of the operation of the AF device  16  by the AF controller  17  and upon stop of the operation of RR  104  by the manual focusing switch  18 ,  19  or at the time of end of the operation of RR  104  by the manual focusing switch  18 ,  19 , and a determining circuit not shown determines whether the detected temperature obtained from the above detector  12  after setting of the reference temperature has a change. When the later detected temperature as a determination object has a change, the AF device  16  is functioned to control the drive of the lens drive unit  9 , based on the in-focus signal of the AF device  16 , to move RR  104  to the in-focus position, thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. This can correct the variation in the position of the image plane of the optical system due to the change of ambient temperature, thereby obtaining good image information.  
         [0071]    The operation of the fifth embodiment is next explained using the flowchart of FIG. 8. It is determined at step  1401  whether the AF function of the AF device  16  is on or off. If it is on, the AF off flag is cleared at step  1402  and the flow returns to step  1401 . If the AF function is off, it is determined at step  1403  whether the MFD switch  18  or  19  is on. If either one is on, the MFD off flag is cleared at step  1404  and the flow returns to step  1401 . If they are off, it is determined at step  1405  whether the MFD off flag is cleared. If cleared, a temperature detection value is read at step  1406 , the temperature detection value (detected temperature) is set as a reference temperature at step  1407 , and the MFD off flag is set at step  1408 .  
         [0072]    If at step  1405  the MFD off flag is not cleared, i.e., if it is set, a temperature detection value is read at-step  1409  and it is determined at step  1410  whether the temperature detection value (detected temperature) is equal to the reference temperature. If they are equal, the flow returns to step  1401 . If they are different, step  1411  is carried out to perform the temperature compensated AF control for moving RR  104  to the in-focus position by the AF function, and then step  1412  is carried out to update the reference temperature by setting the above detected temperature, which was the determination object with respect to the above reference temperature, as a new reference temperature. Then the flow returns to step  1401 .  
         [0073]    As described above, the fifth embodiment is arranged in such a way that in the stop state of the operation of the AF device  16  by the AF controller  17  and upon stop of the operation of RR  104  by the manual focusing switch  18 ,  19  or at the time of end of the operation of RR  104 , the detected temperature obtained from the detector  12  is set as a reference temperature and that when the detected temperature obtained from the detector  12  changes relative to the reference temperature, the function of the AF device  16  is utilized to move RR  104  to the in-focus position so as to effect the temperature compensated AF control, thereby obtaining good image information.  
         [0074]    The manual focusing devices  18 ,  19  may be any means that can detect the operation such as on/off without having to be limited to on/off of the switches described above.  
         [0075]    The optical apparatus of the sixth embodiment shown in FIG. 9 is arranged to have the manual zooming devices  20 ,  21  for manually achieving drive of the lens drive unit  8  through the controller  7  to effect zooming of the variator lens  102 , and thus has the same arrangement as the optical apparatus of the third embodiment. Since the configuration of the present embodiment is the same as that of FIG. 5, description of the individual components is omitted herein.  
         [0076]    The sixth embodiment is arranged so that in the stop state of the operation of the AF device  16  by the AF controller  17  and when the view angle is changed by the zooming operation through the manual zooming switch  20 ,  21 , it is determined that the idle state for photography after idle is broken, the ambient temperature is stored at the end of the zooming operation by the manual zooming switch  20 ,  21 , it is assumed thereafter that the idle state is again established, and when the ambient temperature of the optical system  1  changes in such an idle state, the function of the AF device  16  is utilized to move RR  104  to the in-focus position, thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature.  
         [0077]    Specifically, in the stop state of the operation of the AF device  16  by the AF controller  17  and upon completion of the zooming operation of the variator lens  102  by the manual zooming device  20 ,  21 , the controller  7  sets the detected temperature obtained from the detector  12  as a reference temperature, and a determining circuit not shown determines whether a detected temperature obtained from the above detector  12  after setting of the reference temperature has a change. When the later detected temperature as a determination object has a change, the AF device  16  is functioned to control the drive of the lens drive unit  9 , based on the in-focus signal from the AF device  16  so as to move RR  104  to the in-focus position, thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. This can correct the variation in the position of the image plane of the optical system due to the change of ambient temperature, thereby obtaining good image information.  
         [0078]    The operation of the sixth embodiment is next explained using the flowchart of FIG. 9. It is determined at step  1601  whether the AF function of the AF device  16  is on or off. If it is on, the AF off flag is cleared at step  1602  and the flow returns to step  1601 . If the AF function is off, it is determined at step  1603  whether the zoom switch  20  or  21  is on or off. If either one is on, the zoom off flag is cleared at step  1604  and then the flow returns to  1601 . If they are off, it is determined at step  1605  whether the zoom off flag is cleared. If it is cleared, a temperature detection value is read at step  1606 , the temperature detection value (detected temperature) is set as a reference temperature at step  1607 , and the zoom off flag is set at step  1608 .  
         [0079]    If at step  1605  the zoom off flag is not cleared, that is, if it is set, a temperature detection value is read at step  1609 , and it is determined at step  1610  whether the temperature detection value (detected temperature) is equal to the reference temperature. If they are equal, the flow returns to step  1601 . If they are different, step  1611  is carried out to effect the temperature compensated AF control for moving RR  104  to the in-focus position by the AF function and then step  1612  is carried out to set the above detected temperature as a reference temperature. Then the flow returns to step  1601 .  
         [0080]    As described above, the sixth embodiment is arranged in such a way that in the stop state of the operation of the AF device  16  by the AF controller  17  and at the end of the zooming operation by the manual zooming device  20 ,  21 , the detected temperature obtained from the detector  12  is set as a reference temperature and that when the detected temperature obtained from the detector  12  changes with respect to the reference temperature, the function of the AF device  16  is utilized to move RR  104  to the in-focus position so as to effect the temperature compensated AF control, thereby obtaining good image information.  
         [0081]    The manual zooming devices  20 ,  21  may be any means that can detect the operation such as on/off, without having to be limited to on/off of the switches described above.  
         [0082]    The optical apparatus of the seventh embodiment shown in FIG. 10 and FIG. 11 is constructed in the same structure as the optical apparatus of the first embodiment except for the controller  7 ′. In more detail, the optical apparatus of the seventh embodiment is provided with such a temperature compensated control function that a memory portion (memory means) not shown of the controller  7 ′ for controlling the whole of the optical apparatus stores position data of the moving lens unit (RR lens)  104  at a reference temperature TO (reference ambient temperature) (which is set at 20° C. in the seventh embodiment) described hereinafter, and control information including plural temperature compensation coefficient data Trr per unit temperature for correcting this position data based on an ambient temperature (detected temperature) from the detector  12 , that the above temperature correction coefficient data Trr is multiplied by a temperature change value ΔT, which is an absolute value of a difference between the detected temperature from the detector  12  and the above reference temperature, to obtain correction amount data (temperature corrected position data) Prr for correction for variations in the position of the image plane due to changes of ambient temperature of the optical system, and that the lens drive unit  9  moves RR  104  along the direction of the optical axis by this correction amount Prr.  
         [0083]    The following equations represent the relation among the temperature change value ΔT, focus movement amount Trr, and correction amount Prr in such a temperature compensated control function. 
         Δ T =|detected temperature−reference ambient temperature| 
         
       Prr=ΔT×Trr 
     
         [0084]    Here, the temperature correction coefficient data Trr is defined as a function of position of the moving lens unit for magnification change. The above equations can be applied to humidity changes as they are.  
         [0085]    In the seventh embodiment, when the operation (function) of the AF device  16  is stopped (or turned off) by the AF controller  17 , the ambient temperature of the optical system  1  is detected by the detector  12  and then is stored, and it is determined whether a temperature change value ΔT of a difference between a latest detected temperature obtained from the detector  12  after the foregoing ambient temperature and the reference temperature is more than a predetermined, specific value Kt described hereinafter. If the temperature change value ΔT is not more than the specific value Kt, the correction amount (temperature corrected position data) Prr is obtained from the above relation, and the lens drive unit  9  moves RR  104  to correct variation in the position of the image plane of the optical system due to the change of ambient temperature. On the other hand, if the above temperature change value ΔT is more than the specific value Kt, the above function of the AF device  16  is utilized to move RR  104  to the in-focus position, thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature.  
         [0086]    Specifically, the controller  7 ′ stores the detected temperature obtained from the detector  12  when the operation (function) of the AF means  16  is stopped (or turned off) by the AF controller  17 . Then the controller  7 ′ calculates the temperature change value ΔT of the difference between the latest detected temperature obtained from the detector  12  after the previously detected temperature and the reference temperature and determines whether the absolute value of this temperature change value ΔT is more than the predetermined, specific value Kt. If the absolute value of the temperature change value ΔT is not more than the predetermined, specific value Kt, the controller obtains the correction amount (temperature corrected position data) Prr from the foregoing relation and moves RR  104  by the lens drive unit  9 , based thereon, thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. On the other hand, if the absolute value of the temperature change value ΔT is more than the specific value Kt, the above AF device  16 , is functioned to control the drive of the lens drive unit  9 , based on the in-focus signal of the AF device  16 , to move RR  104  to the in-focus position, thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. This can correct the variation in the position of the image plane of the optical system due to the change of ambient temperature, thereby obtaining good image information.  
         [0087]    The operation of the seventh embodiment is next explained using the flowchart of FIG. 11. It is determined at step  1201 ′ whether the AF function of the AF device  16  is on or off. If it is on, the AF off flag is cleared at step  1202 ′ and then the flow returns to step  1201 ′. If the AF function is off, it is determined at step  1203 ′ whether the AF off flag is cleared. If cleared, the temperature detection value is read by the detector  12  at step  1204 ′, the temperature detection value (detected temperature) is set as a detected temperature T 1  in the MF (manual focus) mode at step  1205 ′, and then the AF off flag is set at step  1206 ′.  
         [0088]    If at step  1203 ′ the AF off flag is not cleared, that is, if it is set, a temperature detection value is read by the detector  12  at step  1207 ′, and it is determined at step  1208 ′ whether the temperature detection value (detected temperature) is equal to the previous detected temperature T 1 . If they are equal, the flow returns to step  1201 ′. If they are different, step  1209 ′ is carried out to obtain a temperature change value ΔT of a difference between the later detected temperature obtained at step  1207 ′ and the reference temperature T 0  and to determine if the absolute value thereof is more than the predetermined, specific value Kt. If the temperature change value ΔT is not more than the specific value Kt, step  1210 ′ is carried out to obtain the correction amount Prr from the above relation and to move RR  104 , thereby effecting the temperature compensated control for correcting the variation in the position of the image plane of the optical system. On the other hand, if at step  1209 ′ the absolute value of the temperature change value ΔT is more than the specific value Kt, step  1211 ′ is carried out to execute the temperature compensated AF control to move RR  104  to the in-focus position by the AF function. Then step  1212 ′ is carried out to update the previously detected temperature T 1  to the later detected temperature. Then the flow returns to step  1201 ′.  
         [0089]    As described above, the seventh embodiment is arranged in such a way that when the operation of the AF device  16  is stopped by the AF controller  17 ′ and if the temperature change value ΔT of the difference between the latest detected temperature obtained from the detector  12  and the reference temperature is not more than the predetermined, specific value Kt, the controller executes the temperature compensated control to obtain the correction amount Prr of RR  104 , to move RR  104  by the lens drive unit  9 , and to correct the variation in the position of the image plane of the optical system and that, on the other hand, if the absolute value of the temperature change value ΔT is more than the specific value Kt, the controller executes the temperature compensated AF control to move RR  104  to the in-focus position utilizing the function of the AF device  16 , thereby achieving good image information.  
         [0090]    There is no specific limitation on the reference temperature T 0  in the seventh embodiment. For example, it may be a temperature upon execution of lens adjustment or a reference value being an absolute value of a desired temperature. It is, however, preferred to determine the reference temperature at an approximate value to ambient temperatures at which the optical apparatus is actually used, because it causes little error in arithmetic processing.  
         [0091]    The specific value Kt for determining whether the AF function is to be actuated may be determined arbitrarily depending upon optical characteristics of the optical system, material characteristics, specifications of the optical apparatus, and so on. In addition, the specific value may be arranged to be stored in a rewritable memory unit so as to be changed any time with necessity.  
         [0092]    The optical apparatus of the eighth embodiment shown in FIG. 12 and FIG. 13 is constructed in the same structure as the optical apparatus of the seventh embodiment except for provision of the manual focusing devices  18 ′,  19 ′ for focusing RR  104  by manually driving the lens drive unit  9  through the controller  7 ′.  
         [0093]    In FIG. 12, numerals  18 ′,  19 ′ denote switches for manual focus adjustment (hereinafter referred to as MFD). With either switch kept in the on state, the switch  18 ′ drives RR  104  to the nearest extreme or the switch  19 ′ drives RR  104  to the infinite extreme.  
         [0094]    The eighth embodiment is based on the premise that the focus position at the end of the MFD operation is the in-focus position and that the ambient temperature at the end  6 f the operation of RR  104  is detected as a reference temperature. In more detail, while the operation of the AF device  16  is stopped by the AF controller  17 ′ and when the manual focusing is carried out, the controller stores an ambient temperature upon stop of the operation of RR  104  or at the end of the operation of RR  104  and then determines whether a temperature change value ΔT of a difference between a latest detected temperature obtained from the detector  12  after the ambient temperature and the reference temperature is more than a predetermined, specific value Kt described below. If the temperature change value ΔT is not more than the predetermined, specific value Kt, the controller obtains the correction value (temperature corrected position data) Prr from the above relation and to move RR  104  by the lens drive unit  9 , thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. On the other hand, if the above temperature change value ΔT is more than the specific value Kt, the controller moves RR  104  to the in-focus position utilizing the function of the above AF device  16 , thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature.  
         [0095]    Specifically, while the operation of the AF device  16  is stopped by the AF controller  17 ′ and upon stop of the operation of RR  104  by the manual focusing switch  18 ′,  19 ′ or at the time of end of operation of RR  104  by the manual focusing switch  18 ′,  19 ′, the controller  7 ′ stores the detected temperature obtained from the detector  12  and calculates the temperature change value ΔT of the difference between the latest detected temperature obtained from the detector  12  after the previously detected temperature and the reference temperature, and a determining circuit not shown determines whether the absolute value of this temperature change value ΔT is more than the predetermined, specific value Kt. If the absolute value of the temperature change value ΔT is not more than the predetermined, specific value Kt, the controller obtains the correction amount (temperature corrected position data) Prr from the foregoing relation and to move RR  104  by the lens drive unit  9 , thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. On the other hand, if the absolute value of the temperature change value ΔT is more than the specific value Kt, the above AF device  16  is functioned to control the drive of the lens drive unit  9 , based on the in-focus signal of the AF device  16 , to move RR  104  to the in-focus position, thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. This can compensate for the variation in the position of the image plane of the optical system due to the change of ambient temperature, thereby attaining good image information.  
         [0096]    The operation of the eighth embodiment is next explained using the flowchart of FIG. 13. It is determined at step  1401 ′ whether the AF function of the AF device  16  is on or off. If it is on, the AF off flag is cleared at step  1402 ′ and then the flow returns to step  1401 ′. If the AF function is off, it is determined at step  1403 ′ if the AF off flag is cleared. If cleared, step  1404 ′ is carried out to read a temperature detection value by the detector  12  and then step  14051  is carried out to set the temperature detection value (detected temperature) as a detected temperature T 1  in the MF (manual focus) mode. Then step  1206 ′ is carried out to set the AF off flag.  
         [0097]    If at step  1403 ′ the AF off flag is not cleared, that is, if it is set, it is determined at step  1407 ′ whether the switch  18 ′ or  19 ′ of MFD is on or off at step  1407 ′. If either one is on, the MFD off flag is cleared at step  1408 ′ and then the flow returns to step  1401 ′. If they are off, it is determined at step  1409 ′ whether the MFD off flag is cleared. If it is cleared, the MFD off flag is set at step  1410 ′, a temperature detection value is read at step  1404 ′, and the processes including step  1405 ′ and the subsequent processes are carried out.  
         [0098]    If at step  1409 ′ the MFD off flag is not cleared, that is, if it is set, a temperature detection value is read at step  1411 ′ and it is determined at step  1412 ′ whether the temperature detection value (detected temperature) is equal to the previously detected temperature T 1 . If they are equal, the flow returns to step  1401 ′. If they are different, step  1413 ′ is carried out to obtain the temperature change value ΔT of the difference between the later detected temperature obtained at step  1411 ′ and the reference temperature T 0  and to determine if the absolute value thereof is more than the predetermined, specific value Kt. If the temperature change value ΔT is not more than the specific value Kt, step  1414 ′ is carried out to execute the temperature compensated control to obtain the correction amount Prr from the foregoing relation and to move RR  104 , thereby correcting the variation in the position of the image plane of the optical system. On the other hand, if at step  1413 ′ the absolute value of the temperature change value ΔT is more than the specific value Kt, step  1415 ′ is carried out to execute the temperature compensated AF control to move RR  104  to the in-focus position by the AF function and then step  1416 ′ is carried out to update the previously detected temperature T 1  to the later detected temperature. Then the flow returns to step  1401 ′.  
         [0099]    As described above, the eighth embodiment is arranged in such a way that while the operation of the AF device  16  is stopped by the AF controller  17 ′ and upon stop of the operation of RR  104  by the manual focusing switch  18 ′,  19 ′ or at the end of the operation of RR  104 , if the temperature change value ΔT of the difference between the latest detected temperature obtained from the detector  12  and the reference temperature is not more than the predetermined, specific value Kt, the controller executes the temperature compensated control to obtain the correction amount Prr of RR  104  and move RR  104  by the lens drive unit  9  so as to compensate for the variation in the position of the image plane of the optical system and that, on the other hand, if the absolute value of the temperature change value ΔT is more than the specific value Kt, the controller executes the temperature compensated AF control to move RR  104  to the in-focus position utilizing the function of the above AF device  16 , thereby obtaining good image information.  
         [0100]    The manual focusing devices  18 ′,  19 ′ may be any means that can detect the operation such as on/off, without having to be limited to on/off of switch as described above.  
         [0101]    The optical apparatus of the ninth embodiment shown in FIG. 14 and FIG. 15 is constructed in the same structure as the optical apparatus of the seventh embodiment except for provision of the manual zooming devices  20 ′,  21 ′ for zooming the variator lens  102  by manually driving the lens drive unit  8  through the controller  7 ′.  
         [0102]    In FIG. 14, numerals  20 ′,  21 ′ designate manual zooming switches. With either switch kept in the on state, the switch  20 ′ drives the variator lens  102  to the telephoto end or the switch  19 ′ drives the variator lens  102  to the wide angle end.  
         [0103]    In the ninth embodiment, while the operation of the AF device  16  is stopped by the AF controller  17  and when the view angle is changed by the zooming operation with the manual zooming switch  20 ′,  21 ′, the controller determines that the idle state for photography after idle is broken, it stores the ambient temperature at the end of the zoom operation by the manual zoom switch  20 ′,  21 ′, then it assumes that the idle state is again established thereafter, the controller makes the detector  12  detect the ambient temperature in such an idle state to store the ambient temperature detected, and it determines whether the temperature change value ΔT of the difference between the latest detected temperature obtained from the detector  12  after the ambient temperature and the reference temperature is more than the predetermined, specific value Kt as described previously. If the temperature change value ΔT is not more than the predetermined, specific value Kt, the controller obtains the correction amount (temperature corrected position data) Prr from the previous relation and to move RR  104  by the lens drive unit  9  so as to compensate for the variation in the position of the image plane of the optical system due to the change of ambient temperature. On the other hand, if the above temperature change value ΔT is more than the specific value Kt, the controller moves RR  104  to the in-focus position utilizing the function of the above AF unit  16 , thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature.  
         [0104]    Specifically, while the operation of the AF device  16  is stopped by the AF controller  17 ′ and at the end of the zoom operation of the variator lens  102  by the manual zooming device  20 ′,  21 ′, the controller  7  stores the detected temperature obtained from the detector  12  and calculates the temperature change value ΔT of the difference between the latest detected temperature obtained from the detector  12  after the previously detected temperature and the reference temperature and a determining circuit not shown determines whether the absolute value of this temperature change value ΔT is more than the predetermined, specific value Kt. If the absolute value of the temperature change value ΔT is not more than the predetermined, specific value Kt, the controller obtains the correction amount (temperature corrected position data) Prr by the previous relation and moves RR  104  by the lens drive unit  9 , thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. On the other hand, if the absolute value of the temperature change value ΔT is more than the specific value Kt, the above AF device  16  is functioned to control the drive of the lens drive unit  9 , based on the in-focus signal of the AF device  16 , to move RR  104  to the in-focus position, thereby correcting the variation in the position of the image plane of the optical system due to the change of ambient temperature. This can correct the variation in the position of the image plane of the optical system due to the change of ambient temperature, thereby obtaining good image information.  
         [0105]    The operation of the ninth embodiment is next explained using the flowchart of FIG. 15. It is determined at step  1601 ′ whether the AF function of the AF device  16  is on or off. If it is on, the AF off flag is cleared at step  1602 ′ and then the flow returns to step  1601 ′. If the AF function is off, it is determined at step  1603 ′ whether the AF off flag is cleared. If cleared, a temperature detection value is read by the detector  12  at step  1604 ′, the temperature detection value (detected temperature) is set as a detected temperature T 1  in the MF (manual focus) mode at step  1605 ′, and the AF off flag is set at step  1606 ′.  
         [0106]    If at step  1603 ′ the AF off flag is not cleared, that is, if it is set, step  1607 ′ is carried out to determine whether the manual zooming switch  20 ′ or  21 ′ is on or off. If either one is on, the zoom off flag is cleared at step  1608 ′ and then the flow returns to step  1601 ′. If they are off, it is determined at step  1609 ′ whether the zoom off flag is cleared. If it is cleared, the zoom off flag is set at step  1610 ′, a temperature detection value is read at step  1604 ′, and the processes including step  1605 ′ and the subsequent steps are carried out.  
         [0107]    If at step  1609 ′ the zoom off flag is not cleared, that is, if it is set, a temperature detection value is read at step  1611 ′ and it is determined at step  1612 ′ whether the temperature detection value (detected temperature) is equal to the previously detected temperature T 1 . If they are equal, the flow returns to step  1601 ′. If they are different, step  1613 ′ is carried out to obtain the temperature change value ΔT of the difference between the later detected temperature obtained at step  1611 ′ and the reference temperature T 0  and to determine whether the absolute value thereof is more than the predetermined, specific value Kt. If the temperature change value ΔT is not more than the specific value Kt, step  1614 ′ is carried out to execute the temperature compensated control to obtain the correction amount Prr from the previous relation and to move RR  104  so as to compensate for the variation in the position of the image plane of the optical system. On the other hand, if at step  1613 ′ the absolute value of the temperature change value ΔT is more than the specific value Kt, step  1615 ′ is carried out to execute the temperature compensated AF control to move RR  104  to the in-focus position by the AF function. Then step  1616 ′ is carried out to update the previously detected temperature T 1  to the later detected temperature. Then the flow returns to step  1601 ′.  
         [0108]    As described above, the ninth embodiment is arranged in such a way that while the operation of the AF device  16  is stopped by the AF controller  17  and at the end of the zoom operation of the variator lens  102  by the manual zooming device  20 ′,  21 ′, if the temperature change value ΔT of the difference between the latest detected temperature obtained from the detector  12  and the reference temperature is not more than the predetermined, specific value Kt, the controller executes the temperature compensated control to obtain the correction amount Prr of RR  104  and to move RR  104  by the lens drive device  9  so as to correct the variation in the position of the image plane of the optical system and that, on the other hand, if the absolute value of the temperature change value ΔT is more than the specific value Kt, the controller executes the temperature compensated AF control to move RR  104  to the in-focus position utilizing the function of the above AF device  16 , thereby obtaining good image information.  
         [0109]    The manual zooming devices  20 ′,  21 ′ may be any means that can detect the operation such as on/off, without having to be limited to on/off of switch as described above.  
         [0110]    As detailed above, since the optical apparatus of the present embodiment is constructed as described above, it can obtain good image information without defocus even with occurrence of temperature changes during zooming and during the operation of AF function or during stop of the AF function, or in the cases where the temperature is constant but deviates from the reference temperature.  
         [0111]    The optical apparatus of the present embodiment uses a single detector  12 , but it may be arranged to use plural detectors  12  for compensation for variations in the position of the image plane of the optical system  1 , which enables higher-accuracy temperature compensated control.  
         [0112]    The optical apparatus of the present embodiment was described as the example where the environmental changes were the temperature changes, but in the cases where the environmental changes are humidity changes or pressure changes, the apparatus can handle such changes in the same manner in the foregoing structure with provision of a detector thereof. For example, the apparatus may be arranged to have either a temperature detector or a humidity detector, or the apparatus may be arranged to have the both detectors so as to correct defocus due to the temperature changes and humidity changes.  
         [0113]    As explained above, since the above embodiments are arranged so that during photography with operation of the AF device using the optical system (photographing lens) having the moving lens unit arranged to move on the optical axis for focus or magnification change, when the AF function is stopped for some reason and, for example, if environmental changes such as temperature changes or humidity changes occur, the AF function is utilized to control the drive of the moving lens unit by the lens drive unit according to the environment changes, the apparatus can correct the deviation in the position of the image plane caused by the environmental change with high accuracy and can maintain high optical performance, thereby providing the optical apparatus suitable for video cameras, silver-salt cameras, electronic still cameras, and so on.  
         [0114]    Since the optical apparatus is arranged so that during photography with operation of the AF device using the optical system (photographing lens) having the moving lens unit arranged to move on the optical axis for focus or magnification change, when the AF function is stopped for some reason and, for example, if an environmental change such as a temperature change or a humidity change occurs, the AF function is utilized to control the drive of the moving lens unit by the lens drive unit according to the environmental change, or movement of the moving lens unit is properly determined every time from control information according to the environment change and the lens drive unit controls the drive of the moving lens unit, based thereon, the apparatus can correct the deviation in the position of the image plane caused by the environment change with high accuracy and can maintain high optical performance, thereby providing the optical apparatus suitable for video cameras, silver-salt cameras, electronic still cameras, and so on.