Abstract:
Electronic binoculars are provided that comprise an imaging unit, a first binocular unit, a second binocular unit, and a mode selector. The imaging unit captures an image of an object. The first binocular unit comprises a first ocular unit through which the object is observed based on signals from the imaging unit. The second binocular unit comprises a second ocular unit through which the object is observed based on signals from the imaging unit. The mode selector selects at least one of first and second modes. The first mode fully supplies electricity to each of the first and second binocular units. The second mode at least partially suspends the electricity supply to the second binocular unit.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to electronic binoculars, in particular, to electric improved energy-saving electronic binoculars.  
           [0003]    2. Description of the Related Art  
           [0004]    Electronic binoculars are proposed that are capable of recording image data in a storage medium and further having the advantage of night vision. The electronic binoculars are generally provided with an objective optical system, an imaging device, an image-signal processing unit, and an ocular unit. The imaging device converts an optical image produced by the objective optical system to electric signals. The image-signal processing unit generates image signals from the electric signals which are detected by the imaging device, so that the object image can be visually indicated by the ocular unit. The ocular unit has an image-indicating device that displays the object image due to the image signals generated by the image-signal processing unit.  
           [0005]    An imaging device, such as a CCD, as well as an image-indicating device, such as an LCD, consume electricity. Further, the image-signal processing unit that converts the electric signals from the imaging device to image signals, in order to visually indicate the object image on the ocular unit or to store the image signals in the storing medium, also consumes electricity. Therefore, such electronic binoculars are not suitable for extended use from the aspect of electricity consumption.  
           [0006]    Japanese unexamined patent publication (KOKAI) No. 2001-281555 discloses electronic binoculars provided with an imaging device for electronic imaging; in addition to and separate from a binocular optical system, which has a pair of observation optical systems, including objective lens and ocular lens systems, as is known in the art. According to the above-disclosed binoculars, although the imaging device for capturing an object image and the ocular unit consume electricity, object images can be observed without consuming electricity through the conventional binocular optical system which is separately provided in the binoculars.  
         SUMMARY OF THE INVENTION  
         [0007]    However, the structure of the above-discussed conventional electronic binoculars is cumbersome and complicated, since the electronic binocular systems are provided in addition to the conventional binocular optical system.  
           [0008]    Therefore, an object of the present invention is to provide binoculars that can reduce electric energy consumption without reducing the advantages of the electronic binoculars.  
           [0009]    According to the present invention, electronic binoculars are provided that comprise an imaging unit, a first binocular unit, a second binocular unit, and a mode selector.  
           [0010]    The imaging unit captures an image of an object. The first binocular unit comprises a first ocular unit through which the object is observed based on signals from the imaging unit. The second binocular unit comprises a second ocular unit through which the object is observed based on signals from the imaging unit. The mode selector selects at least one of first and second modes. The first mode fully supplies electricity to each of the first and second binocular units. The second mode at least partially suspends the electricity supply to the second binocular unit. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which:  
         [0012]    [0012]FIG. 1 is a perspective view of electronic binoculars in the first embodiment viewed from the objective lens side;  
         [0013]    FIGS.  2  is a perspective view of the electronic binoculars in the first embodiment viewed from the ocular lens side;  
         [0014]    [0014]FIG. 3 is a top plan view of a slidable operational member of a switch when it is positioned at a power-off position;  
         [0015]    [0015]FIG. 4 is a top plan view of the slidable operational member of the switch when it is positioned at a normal mode position;  
         [0016]    [0016]FIG. 5 is a top plan view of the slidable operational member of the switch when it is positioned at a first energy-saving mode position;  
         [0017]    [0017]FIG. 6 is a top plan view of the slidable operational member of the switch when it is positioned at a second energy-saving mode position;  
         [0018]    [0018]FIG. 7 is a diagram of switch contacts verified by a controller to define the mode selection of the switch in the first embodiment;  
         [0019]    [0019]FIG. 8 is a block diagram of the electronic binoculars of the first embodiment, which schematically depicts the state of the normal mode;  
         [0020]    [0020]FIG. 9 is a block diagram of the electronic binoculars of the first embodiment, which schematically depicts the state of the first energy-saving mode;  
         [0021]    [0021]FIG. 10 is a block diagram of the electronic binoculars of the first embodiment, which schematically depicts the state of the second energy-saving mode;  
         [0022]    [0022]FIG. 11 is a diagram of switch contacts verified by a controller to define the mode selection of the switch in the second embodiment;  
         [0023]    [0023]FIG. 12 is a block diagram of the electronic binoculars of the second embodiment, which schematically depicts the state of the normal mode;  
         [0024]    [0024]FIG. 13 is a block diagram of the electronic binoculars of the second embodiment, which schematically depicts the state of the first energy-saving mode;  
         [0025]    [0025]FIG. 14 is a block diagram of the electronic binoculars of the second embodiment, which schematically depicts the state of the second energy-saving mode;  
         [0026]    [0026]FIG. 15 is a perspective view of the electronic binoculars of the third embodiment viewed from the objective lens side;  
         [0027]    [0027]FIG. 16 is a perspective view of the electronic binoculars of the third embodiment viewed from the ocular lens side;  
         [0028]    [0028]FIG. 17 is a diagram of switch contacts verified by a controller to define the mode selection of the switch in the third embodiment;  
         [0029]    [0029]FIG. 18 is a block diagram of the electronic binoculars of the third embodiment, which schematically depicts the state of the normal mode;  
         [0030]    [0030]FIG. 19 is a block diagram of the electronic binoculars of the third embodiment, which schematically depicts the state of the energy-saving mode. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]    The present invention is described below with reference to the embodiments shown in the drawings.  
         [0032]    As shown in FIGS.  1  to  8 , electronic binoculars relating to the first embodiment are provided with an electric power source  90 , right and left binocular units  1 R and  1 L, a controller  70 , and a switch  80 . Both the right and left binocular units  1 R and  1 L have the same constructions. Namely, the right and left binocular units  1 R and  1 L include imaging units  10 R and  10 L, ocular units  30 R and  30 L, and image-signal processing units  50 R and  50 L, respectively. The right and left binocular units  1 R and  1 L are connected together via a connecting mechanism so that the distance between the optical axes of the respective optical systems is adjusted.  
         [0033]    The right imaging unit  10 R is provided with an objective lens system  11 R, a filter system including an infrared cut-off filter, an optical low-pass filter, and the like, and an imaging device  13 R, such as a CCD. The imaging device  13 R converts an optical image that is magnified through the objective lens system  11 R and the filter system  12 R, and which is projected onto the imaging device  13 R, to electric signals. The right imaging unit  10 R may include a focusing mechanism, which is not depicted in the figures. Similarly, the left imaging unit  10 L is provided with an objective lens system  11 L, a filter system  12 L, and an imaging device  13 L.  
         [0034]    The right ocular unit  30 R includes an image-indicating device, such as an LCD, and an ocular lens system  31 R. The image-indicating device displays an image corresponding to image signals fed from the controller  70 . Namely, an observer observes the image displayed on the image-indicating device through the ocular lens system  31 R. Similarly, the left ocular unit  30 L includes an image-indicating device  33 L and an ocular lens system  31 L.  
         [0035]    A right image-signal processing unit  50 R (a first image-signal processing unit) includes an imaging device driver  51 R, a correlated double sampling circuit (CDS)  52 R, a timing generator (TG)  53 R, a digital signal processor (DSP)  54 R, an auto-gain controller (AGC)  55 R, and an analog-digital converter (ADC). Namely, the electric signals generated in the right imaging unit  10 R from a captured image are converted to image signals which can be displayed and observed by the right ocular unit  30 R. Further, the right image-signal processing unit  50 R may include a function that converts the electric signals to image signals (for example, compressed image signals) for recording the image signals in an external storing medium. The same is true with the left image-signal processing unit  50 L (a second image-signal processing unit). Namely, the left image-signal processing unit  50 L includes an image-indicating driver  51 L, a correlated double sampling circuit  52 L, a timing generator  53 L, a digital signal processor  54 L, and an analog-digital converter  56 L.  
         [0036]    The controller  70  is a microcomputer that integrally controls the processes among the components in the right and left binocular units. For example, the controller  70  includes a function for feeding image signals generated by both the right and left image-signal processing units  50 R and  50 L to the respective ocular units  30 R and  30 L, and a function for controlling electric power supply from the electric power source  90  to each of the components.  
         [0037]    Further, the controller  70  has a function for controlling the electric supply to the left imaging unit  10 L, the left image-signal processing unit  50 L, and the left ocular unit  30 L, and also a function for controlling the image signal supply to the left ocular unit  30 L, in accordance with the state of the switch  80 , i.e., which contact/s is/are connected among all the contacts in the switch.  
         [0038]    Switch  80  has a manual slidable operational member  80   a  and switch contacts that are selected in accordance with the positions of the operational member  80   a  for enabling a user to select one of modes by operating the operational member  80   a , to define units or components to which the electricity is supplied from the power source  90 . FIGS.  3  to  6  indicate the details of the operational member  80   a . As shown in FIGS.  3  to  6 , the switch  80  has three selective modes, that is, a normal mode and first and second energy saving modes. Note that, in FIGS. 1 and 2, the normal mode, and the first and second energy-saving modes are represented by or abbreviated to “ON”, “1st”, and “2nd”, respectively, for convenience. When the user slides or operates the operational member  80   a  from the power-off position (see FIG. 3) to the position corresponding to the normal mode (see FIG. 4), that is, turning on the power and selecting the normal mode, a normal-mode contact of the switch  80  that designates the electricity to be supplied to all components is switched to the ON state while other contacts are suspended in the OFF state. Thereby, the controller  70  detects this ON state and verifies the selection of the normal mode (see FIG. 7). In this case, the electricity is supplied to all components of the electronic binoculars, that is, to both of the right and left imaging units  10 R and  10 L, both of the right and left ocular units  30 R and  30 L, both of the image-signal processing units  50 R and  50 L, and the controller  70 . FIG. 8 schematically illustrates the state when the electricity is supplied to all of the components of the electronic binoculars, where all of the components to which the electricity is supplied are depicted by solid lines.  
         [0039]    Next, operations of each component will be explained, when the electricity is supplied to each of the components from the power source  90  by the controller  70 .  
         [0040]    Optical object images obtained through the right objective lens system  11 R and the right filter system are projected on the light receiving area of the right imaging device  13 R, and are then subjected to photoelectrical conversion, so that the electric signals corresponding to electric charge accumulated during a predetermined period in the right imaging device  13 R, are generated. The value of the electric charge accumulation period is controlled by the right imaging device driver  51 R.  
         [0041]    The noise components of the electric signals which are obtained by the photoelectrical conversion are reduced by the right correlated double sampling circuit  52 R. Further, the gain of the electric signals is controlled by the right auto-gain controller  55 R. The electric signals are then converted to digital signals by the right analog-digital converter  56 R. These operations are carried out in accordance with clock pulse signals fed from the right timing generator  53 R to the right imaging device driver  51 R and the right correlated double sampling circuit  52 R.  
         [0042]    The converted digital signals (or digital image signals) are subjected to image processes, such as a gamma correction process and so on, in the right digital signal processor  54 R.  
         [0043]    The image signals which were subjected to the image processes, in other words, the image signals which were processed in the right image-signals processing unit  50 R, are supplied to the right image-indicating device  33 R provided in the right ocular unit  30 R by the controller  70 .  
         [0044]    The right image-indicating device  33 R displays the image corresponding to the image signals, so that the observer can observe the image by one&#39;s right eye via the right ocular lens system  31 R.  
         [0045]    At the same time, the same operations are carried out in the left binocular unit  1 L, so that optical object images being captured by the left imaging device are displayed on the left image-indicating device and the images can be observed by the left eye of the observer.  
         [0046]    When the switch  80  is switched from the normal mode or the ON mode to the first energy-saving mode by operating the operational member  80   a , such that when the first energy-saving mode is selected (see FIG. 5), a first energy-saving contact of the switch  80  is connected to be in the ON state while maintaining the normal mode contact in the ON state. The controller  70  detects this contact state, and in turn verifies the selected mode as the first energy-saving mode (see FIG. 7). In this first energy-saving mode, for example, the electricity is supplied to all of the components in the right binocular unit  1 R and the controller  70 , while the electricity is not supplied to the components in the left binocular unit  1 L, except for the left ocular unit  30 L. FIG. 9 schematically illustrates this state. Namely, the units or components being supplied with the electricity are depicted by the solid lines and those not being supplied with the electricity are depicted by the phantom lines. The right image-signal processing unit  50 R converts the electric signals from the right imaging unit  10 R to the image signals. The controller  70  transmits the image signals converted by the right image-signal processing unit  50 R to both of the right and left ocular units  30 R and  30 L. In the first energy-saving mode, although the image capturing operations and the image-signal processing operations are not carried out in the left binocular unit  1 L, in order to reduce the energy consumption, the image captured by the right imaging device  33 R is not only displayed on the right image-indicating device  33 R, but also displayed on the left image-indicating device  33 L, so that binocular vision is still available. Thereby, even when the first energy-saving mode is selected, the observer is free from the blind-in-one-eye feeling and in turn, eyestrain from the observation is reduced.  
         [0047]    When the switch  80  is switched from the first energy-saving mode to the second energy-saving mode by operating the operational member  80   a  (see FIG. 6), a second energy-saving contact of the switch  80  is then connected to be in the ON state while maintaining the normal mode contact in the ON state. The controller  70  detects this contact state, and in turn determines the selected mode as the second energy-saving mode (see FIG. 7). In this second energy-saving mode, the electricity is supplied to the components in the right binocular unit  1 R and the controller  70 , while electricity is not supplied to any of the components in the left binocular unit  1 L. FIG. 10 schematically illustrates this state. Namely, the units or components being supplied with the electricity are depicted by the solid lines and those not being supplied with electricity are depicted by the phantom lines. The right image-signal processing unit  50 R converts only the electric signals from the right imaging unit  10 R to the image signals. Further, the controller  70  transmits the image signals converted by the right image-signal processing unit  50 R only to the right ocular unit  30 R.  
         [0048]    Consequently, according to the first embodiment, the electricity consumption can be reduced compared to that in the normal mode, where the electricity is supplied to both of the imaging units  10 R and  10 L, both of the ocular units  30 R and  30 L, and both of the image-signal processing units  50 R and  50 L, since the electricity supply for the left imaging unit  10 L, the left ocular unit  30 L, and the left image-signal processing unit  50 L, as well as the image signals transmitted to the ocular unit  30 L, can be controlled by the mode selection of a user.  
         [0049]    Further, in the second energy saving mode, the supply of electricity to the left image-indicating device  33 L is also prohibited, so that electricity consumption in the second energy saving mode is reduced compared to the first energy saving mode.  
         [0050]    Next, the second embodiment of the present invention will be explained. As shown in FIGS.  11  to  14 , the difference in structure to the first embodiment is that the electronic binoculars of the second embodiment include only a single image-signal processing unit  50 . Therefore, in the second embodiment, the electric signals obtained by the right and left imaging units  10 R and  10 L are converted to the image signals, which can be displayed in the right and left ocular units  30 R and  30 L, in the single image-signal processing unit  50 . Namely, the electronic binoculars of the second embodiment include the right and left binocular units  2 R and  2 L, the image-signal processing unit  50 , the controller  70 , and the switch  80 . Further, only the constructions dissimilar to those in the first embodiment will be explained in the following.  
         [0051]    The constructions of the image-signal processing unit  50  are identical to those in the first embodiment. However, the second embodiment is dissimilar to the first embodiment in respect of the electric signals obtained by both of the imaging units  10 R and  10 L. There signals are converted to image signals that can be displayed in the respective right and left ocular units  30 R and  30 L, in the single image-signal processing unit  50 , while conversion of the right and left electric signals, in the first embodiment, is respectively carried out separately in the right and left image-signal processing units  50 R and  50 L.  
         [0052]    The construction of the controller  70  is identical to that in the first embodiment. However, unlike the first embodiment in which image signals, converted by each of the right and left image-signal processing units  50 R and  50 L, are fed to the respective right and left ocular units  30 R and  30 L, the controller  70  of the second embodiment feeds right and left image signals converted by the single image-signal processing unit  50  to the respective right and left ocular units  30 R and  30 L.  
         [0053]    Further, the controller  70  controls the electricity supply for the left imaging unit  10 L and the left ocular unit  30 L, and the signal-image supply for the left ocular unit  30 L, in accordance with the state of the switch contacts of the switch  80 .  
         [0054]    The construction of the switch  80  is identical to that in the first embodiment. When the user switches the operational member  80   a  from the power-off position to the normal mode position, the normal-mode contact of the switch  80  is connected to be in the ON state. The controller  70  detects this contact state and verifies that the normal mode is selected (see FIG. 11). When the normal mode is selected, the electricity is supplied to all of the units and components in the electronic binoculars, including the right and left imaging units  10 R and  10 L, the right and left ocular units  30 R and  30 L, the image-signal processing unit  50 , and the controller  70 . FIG. 12 schematically illustrates the state when the electricity is supplied to all of the components of the electronic binoculars, where solid lines depict all of the units or the components to which the electricity is supplied.  
         [0055]    The operations which are carried out in each of the components, when the electricity is supplied thereto from the power source  90  by the controller  70 , are similar to those in the first embodiment, other than the conversion of the electric signals obtained by the right and left imaging units  10 R and  10 L to the image signals, which is performed in the single image-signal processing unit  50 .  
         [0056]    When the switch  80  is switched from the normal mode or the ON mode to the first energy-saving mode by operating the operational member  80   a , such that when the first energy-saving mode is selected, the first energy-saving contact of the switch  80  is connected to be in the ON state while maintaining the normal mode contact in the ON state. The controller  70  detects this contact state, and in turn determines the selected mode as the first energy-saving mode (see FIG. 11). In this first energy-saving mode, for example, the electricity is supplied to all of the components in the right binocular unit  2 R and the controller  70 , while electricity is not supplied to the left imaging unit  10 L in the left binocular unit  2 L. FIG. 13 schematically illustrates this state. Namely, the units or components being supplied with electricity are depicted by the solid lines and those not being supplied with electricity are depicted by the phantom lines. The image-signal processing unit  50  converts the electric signals from the right imaging unit  10 R to image signals. The controller  70  transmits the image signals converted by the image-signal processing unit  50  to both the right and left ocular units  30 R and  30 L. In the first energy-saving mode, although the image capturing operations are not carried out in the left binocular unit  2 L, in order to reduce the energy consumption, the image captured by the right imaging device  33 R is not only displayed on the right image-indicating device  33 R but also on the left image-indicating device  33 L, so that binocular vision is still available. Thereby, even when the first energy-saving mode is selected, the observer is free from the blind-in-one-eye feeling and in turn eyestrain from the observation is reduced.  
         [0057]    When the switch  80  is switched from the first energy-saving mode to the second energy-saving mode by operating the operational member  80   a , the second energy-saving contact of the switch  80  is then connected to be in the ON state while maintaining the normal mode contact in the ON state. The controller  70  detects this contact state, and in turn determines the selected mode as the second energy-saving mode (see FIG. 11). In this second energy-saving mode, the electricity is supplied to all of the components in the right binocular unit  2 R and the controller  70 , while electricity is not supplied to any of the components in the left binocular unit  2 L. FIG. 14 schematically illustrates this state. Namely, the units or components being supplied with electricity are depicted by the solid lines and those not being supplied with electricity are depicted by the phantom lines. The image-signal processing unit  50  converts only the electric signals from the right imaging unit  10 R to image signals. Further, the controller  70  transmits the image signals converted by the right image-signal processing unit  50 R only to the right ocular unit  30 R.  
         [0058]    Consequently, according to the second embodiment, the amount of electricity consumption can be reduced compared to the normal mode, where the electricity is supplied to both the imaging units  10 R and  10 L, both the ocular units  30 R and  30 L, and the image-signal processing unit  50 , since the electricity supply for the left imaging unit  10 L and the left ocular unit  30 L, as well as the transmission of the image signals to the left ocular unit  30 L, are controllable by the mode selection of a user.  
         [0059]    Next, the third embodiment of the present invention will be explained. As shown in FIGS.  15  to  19 , the difference in structure to the first embodiment is that the electronic binoculars of the third embodiment includes only a single imaging unit  10  and a single image-signal processing unit  50 . Therefore, in the third embodiment, the electric signals obtained by the single imaging unit  10  are converted to image signals, which can be displayed in the right and left ocular units  30 R and  30 L, in the single image-signal processing unit  50 . Further, only the constructions dissimilar to those in the first embodiment will be explained in the following.  
         [0060]    The construction of the image-signal processing unit  50  is identical to that in the first embodiment. However, the third embodiment is dissimilar to the first embodiment with respect to the electric signals obtained by the imaging units  10 , which are converted to the image signals that can be displayed in the respective right and left ocular units  30 R and  30 L, in the single image-signal processing unit  50 , while conversion of the right and left electric signals, in the first embodiment, is carried out separately in the right and left image-signal processing units  50 R and  50 L, respectively.  
         [0061]    The construction of the controller  70  is identical to that in the first embodiment. However, unlike to the first embodiment that feeds image signals converted by each of the right and left image-signal processing units  50 R and  50 L to the respective right and left ocular units  30 R and  30 L, the controller  70  of the third embodiment feeds image signals converted by the single image-signal processing unit  50  to both the right and left ocular units  30 R and  30 L.  
         [0062]    Further, the controller  70  controls the electricity supply for the left ocular unit  30 L in accordance with the state of the switch contacts of the switch  80 .  
         [0063]    The switch  80  in the first embodiment is a switch having four selective modes, such as the power-off mode, normal (ON) mode, the first energy-saving mode, and second energy-saving mode, as shown in FIG. 3. On the other hand, the switch  80  in the third embodiment has only three selective modes; the power-off mode, normal (ON) mode, and an energy-saving mode. Note that, in FIGS. 15 and 16, the normal mode and the energy-saving mode are represented by “ON” and “E/S”, respectively. When the user slides or operates the operational member  80   a  from the power-off position to the position corresponding to the normal mode, that is, turning on the power and selecting the normal mode, a normal-mode contact of the switch  80  that designates the electricity to be supplied to all the components, connected to be in the ON state while other contacts are not connected and remain in the OFF state. Thereby, the controller  70  detects this ON state and verifies the selection of the normal mode (see FIG. 17). In this case, the electricity is supplied to all components of the electronic binoculars, that is, to the imaging unit  10 , both the right and left ocular units  30 R and  30 L, the image-signal processing unit  50 , and the controller  70 . FIG. 18 schematically illustrates the state when the electricity is supplied to all of the components of the electronic binoculars, where solid lines depict all of the components to which the electricity is supplied.  
         [0064]    The operations which are carried out in each of the components, when the electricity is supplied thereto from the power source  90  by the controller  70 , are similar to those in the first embodiment, except that the electric signals are obtained by the single imaging unit  10 , and the conversion of the electric signals to the image signals is carried out in the single image-signal processing unit  50 .  
         [0065]    When the switch  80  is switched from the normal mode or the ON mode to the energy-saving mode by operating the operational member  80   a , such that when the energy-saving mode is selected, the energy-saving contact of the switch  80  is made ON state while maintaining the normal mode contact in the ON state. The controller  70  detects this contact state, and in turn verifies the selected mode as the energy-saving mode (see FIG. 17). In this energy-saving mode, the electricity is supplied to the imaging unit  10 , the right ocular unit  30 R, the image-signal processing unit  50 , and the controller  70 , as well as other components of the electronic binoculars, while electricity is not supplied to the left ocular unit  30 L. FIG. 19 schematically illustrates this state. Namely, the units or components being supplied with electricity are depicted by the solid lines and those not being supplied with the electricity are depicted by the phantom lines. The image-signal processing unit  50  converts the electric signals from the imaging unit  10  to image signals. The controller  70  transmits the image signals converted by the image-signal processing unit  50  to the right ocular unit  30 R.  
         [0066]    Consequently, according to the third embodiment, the electricity consumption can be reduced compared to the normal mode, where electricity is supplied to the imaging unit  10 , both of the right and left ocular units  30 R and  30 L, and the image-signal processing unit  50 , since the electricity supplied to the left ocular unit  30 L, as well as the transmission of the image signals to the left ocular unit  30 L, are controllable by the mode selection of the user.  
         [0067]    In the above-described embodiments, electricity consumption was reduced by suspending the electricity supply to the components in the left binocular unit while supplying the electricity to the components in the right binocular unit. However, the consumption may be reduced by suspending the electricity supply to the component in the right binocular unit while supplying electricity to the components in the left binocular unit.  
         [0068]    Although the embodiments of the present invention have been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in this art without departing from the scope of the invention.  
         [0069]    The present disclosure relates to subject matter contained in Japanese Patent Application No. 2003-161741 (filed on Jun. 6, 2003), which is expressly incorporated herein, by reference, in its entirety.