JP4674889B2 - Electronic imaging device - Google Patents

Description

  The present invention relates to an electronic imaging device, and more particularly, to a zoom lens whose depth is extremely thin when stored and an electronic imaging device having the same.

  A conventional zoom lens having a bent optical path (Patent Document 1, etc.) includes at least one lens group B that has a positive refractive power and moves monotonically toward the object side when zooming from the wide-angle end to the telephoto end. The lens group A includes a reflecting optical element that has a negative refractive power and bends the optical path on the object side of the lens group B, and is fixed at the time of zooming. In the case of this type, the depth dimension of the camera housing can be reduced. On the other hand, the number of components can be reduced due to the paraxial refractive power arrangement and the restriction of the entrance pupil position due to the reflection optical element for bending the optical path in the lens group A, the improvement of the zoom magnification, and the aberration correction. Have difficulty. If the aperture stop is not integrated with the lens group B that moves at the time of zooming, an appropriate amount of light cannot be obtained. Therefore, the lens shutter must also move together, and the mechanism is complicated and easily enlarged.

  In addition, as a conventional example, it is suitable for electronic imaging devices among the currently known ones, has excellent imaging performance including zoom ratio, angle of view, F number, etc. Examples of those having the property include Patent Document 2, Patent Document 3, and the like. When the entrance pupil position of the first lens group is made shallow, the diameter of the first lens group becomes smaller, and as a result, the first lens group itself can be made thinner. For this purpose, the magnification of the second lens group is increased, that is, the refractive power is increased. You have to sacrifice imaging performance or sacrifice the depth by increasing the number of components.

  Further, in the conventional technology of a zoom lens having a bent optical path, the fixed lens group having a reflecting surface is a zoom lens whose position is fixed also with respect to the image plane.

A variable magnification optical system having a fixed lens group having a reflecting surface is advantageous in reducing the size of the entire optical system by folding the optical path and overlapping the optical path on the incident side and the optical path on the reflecting side as described above. It becomes. Further, it is advantageous for downsizing the imaging apparatus main body in the thickness direction.
JP 2003-43354 A JP 9-33810 A JP-A-11-142734

  However, in the variable power lens system as in the prior art, in addition to the fixed lens group having a reflecting surface, a plurality of movable lens groups must be provided, and the number of lens groups increases. Alternatively, the movable range of the front lens group or the rear lens group having a reflecting surface is limited, which is disadvantageous for increasing the zoom ratio.

  The present invention has been made in view of such problems of the prior art, and the object thereof is a lens constituting a zoom lens in order to make the thickness in the depth direction extremely small when the lens is retracted (when retracted). By devising the movement of the group, and skillfully incorporating image processing technology, a zoom lens that reduces the total number of lens components to the limit and has extremely high imaging performance in the entire zoom range. It is to provide an electronic imaging device used.

  Another object of the present invention is to provide an electronic image pickup apparatus that can save the number of lens groups and is not disadvantageous for a high zoom ratio even when a fixed lens having a reflecting surface that reflects an optical path is used. is there.

A first electronic imaging apparatus of the present invention that achieves the above object includes a zoom lens that includes a plurality of lens groups and performs zooming by changing an interval between the plurality of lens groups, and an image side of the zoom lens. In an electronic image pickup apparatus provided with an arranged electronic image pickup element,
The zoom lens includes a deflection element that deflects an optical axis, and the deflection element is fixed to the imaging apparatus main body at the time of zooming,
The first lens group, which is one of the plurality of lens groups, is a transmissive lens group that does not have a reflecting surface, is disposed closer to the object side than the deflecting element, and is at the time of zooming The distance to the deflection element changes,
The electronic image pickup device is characterized in that an interval between the deflection device and the deflection device changes at the time of zooming.

  Below, the reason and effect | action which take the said structure in a 1st electronic imaging device are demonstrated.

  In a conventional zoom lens having a bent optical path (eg, Patent Document 1), at least one lens group B having positive refractive power and moving monotonously to the object side when zooming from the wide-angle end to the telephoto end is performed. This type includes a lens unit A that has a negative refractive power on the object side of the lens unit B, includes a reflective optical element for bending the optical path, and is fixed at the time of zooming. In this case, it is possible to reduce the depth of the camera housing, but by providing the lens group A with a reflective optical element for bending the optical path, the zoom magnification by the combination system with the lens group B or subsequent lens groups Improvement is difficult, widening is difficult, and it is difficult to correct aberrations or reduce the number of components.

  Therefore, as in the present invention, the deflection element is fixed to the apparatus main body, and a lens group movable at the time of zooming is arranged on the object side further than that. Since this movable lens group is a transmissive lens group having no reflecting surface, adjacent transmissive surfaces are arranged close to each other, and this is advantageous in correcting aberrations without increasing the size of the lens group.

  In addition, since the reflecting surface is fixed and the electronic image pickup element located on the image side is moved at the time of zooming, the thickness of the entire lens system at the time of photographing can be suppressed.

  In the present invention, a reflective optical element (an optical element having an optical path bending action) for bending the optical path is fixed to the second lens group closer to the electronic imaging element than the first lens group during zooming and focusing. By providing, the above-described problems can be overcome.

  According to a second electronic imaging device of the present invention, in the first electronic imaging device, the deflection element is a mirror.

  The reason and action of the above configuration in the second electronic image pickup apparatus will be described below. An optical element having a bending action (deflection) so that the depth dimension becomes as thin as possible when the lens system is retracted into the camera housing. A mirror is adopted as the element), and the mirror is arranged with its normal inclined to the incident side optical axis (the optical axis of the first lens group) in order to bend the optical path at the time of zooming. For example, when the optical system is retracted in the casing, the mirror is movable, and the second is set to be substantially perpendicular or substantially parallel to the optical axis of the first lens group or the normal of the effective imaging surface of the electronic image sensor. If it is housed together with the lens group, the depth dimension becomes extremely thin.

  According to a third electronic imaging device of the present invention, in the first electronic imaging device, the deflection element is a prism.

  The reason and action of the above configuration in the third electronic imaging device will be described below. As an optical element (deflection element) having a bending action, a prism may be used instead of a mirror. In this case, since the optical path length can be increased, it is advantageous in ensuring back focus and correcting aberrations. Furthermore, when any lens of the second lens group and its prism are integrated, the depth dimension becomes extremely thin.

  According to a fourth electronic imaging device of the present invention, in the first electronic imaging device, the deflection element is disposed between the first lens group and the second lens group.

  Hereinafter, the reason and action of the fourth electronic imaging apparatus having the above configuration will be described. The deflection element may be disposed between the first lens group and the second lens group independently.

  According to a fifth electronic imaging device of the present invention, in the first electronic imaging device, the deflection element is disposed in a second lens group.

  The reason and action of the above configuration in the fifth electronic imaging apparatus will be described below. An optical element (deflection element) having a bending action fixed to the second lens group is arranged in the second lens group. Good. In particular, when correcting astigmatism, the distance on the optical axis between the lens surface closest to the object side and the lens surface closest to the image side in the second lens group should be long, which is contrary to the purpose of the present invention. Therefore, it is more efficient to arrange an optical element such as a mirror or a prism that requires a certain optical path length inside the second lens group.

  According to a sixth electronic imaging apparatus of the present invention, in the first electronic imaging apparatus, the deflection element is disposed on the image side with respect to the second lens group.

  In the following, the reason and action of the above configuration in the sixth electronic imaging device will be described. The distance between the lens group adjacent to the image side of the second lens group or the electronic imaging element is a paraxial amount over the entire zooming focus. Even when a certain amount or more is required for securing or correcting aberrations, it is more efficient to dispose an optical element such as a mirror or prism that requires a certain optical path length on the image side of the second lens group.

  According to a seventh electronic imaging device of the present invention, in the first electronic imaging device, the zoom lens system is disposed in the electronic imaging device, and the electronic imaging device has a finder function (including a display method). The positional relationship between the finder observation surface during magnification and the second lens group does not change during magnification.

  The viewfinder observation surface is a display surface of an observation image, and means a display surface of a display, a field frame of a real image finder, a ground glass surface, and the like.

  The reason why the seventh electronic imaging apparatus adopts the above configuration and the operation will be described below. The zoom lens has a shutter and a bending action by preventing the positional relationship between the viewfinder observation surface and the second lens group from changing. Since it is not necessary to move the position of an optical element (deflection element) or the like, it is easy to make it mechanically simple, and it is easy to make the housing of the electronic imaging device small and thin.

An eighth electronic imaging device of the present invention is the first to seventh electronic imaging devices, wherein the electronic imaging device is obtained by imaging an image formed through the zoom lens with the electronic imaging device. It is possible to process image data and output it as image data with a changed shape. When the zoom lens is focused on any object distance of 50 times or more of f _W , the following conditions are satisfied. It is characterized by satisfaction.

(1) 0.7 <y ₀₈ ^* / (f _W · tan ω _08W ) <0.96
However, f _W is the focal length of the entire system at the wide-angle end of the zoom lens, and the distance (maximum image) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device. If y ₁₀ ^* is high, y ₀₈ ^* = 0.8 y ₁₀ ^* , ω _08W is the optical axis in the object direction corresponding to the image point connecting from the center on the imaging surface at the wide-angle end to the position of y ₀₈ ^* Is an angle with respect to.

  The reason and action of the above configuration in the eighth electronic imaging apparatus will be described below.

In an electronic image pickup apparatus to which the zoom lens of the present invention is applied, that is, a camera having an electronic image pickup element on the image side of the zoom lens, the image formed through the zoom lens is electronically converted so that the distortion of the image can be corrected by distortion. It is preferable that image data obtained by imaging with an imaging element can be processed and output as image data with a changed shape. In that case, it is better to define an allowable level of distortion for the zoom lens. That is, it is preferable that the condition (1) is satisfied when an object distance of 50 times or more of f _W is focused.

  When an image is intentionally formed on the electronic image pickup device with a large barrel distortion at a focal length near the wide-angle end of the zoom lens, the effective diameter of the first lens group that tends to have the largest diameter is obtained. It can be downsized, and as a result, it becomes thinner. Further, when the first lens group is composed of only two components, a negative lens component and a positive lens component, the distance between the two lens components must be a certain value or more in order to correct distortion. However, by allowing the distortion aberration amount, this distance is not necessary so much, and this also contributes to the reduction in thickness. It is also advantageous for correcting astigmatism.

  The barrel-distorted image is photoelectrically converted into image data by an electronic imaging device, and finally subjected to processing corresponding to a shape change by a signal processing system of the electronic imaging device, so that an electronic image is finally obtained. When the image data output from the imaging device is reproduced on some display device, the distortion is corrected and an image substantially similar to the subject shape is obtained.

If there is no distortion in the image obtained by imaging an infinite object,
f = y ^* / tan ω = y / tan ω
Is established. Where y ^* is the height of the image point from the optical axis, y is the height of the ideal image point (image point when the optical system has no distortion) from the optical axis, f is the focal length of the imaging system, ω is an angle with respect to the optical axis in the object direction corresponding to the image point connected from the center on the imaging surface to the position of y ^* .

If the imaging system has barrel distortion,
f> y ^* / tanω
It becomes. That is, if f and y are constant, ω is a large value.

  Condition (1) defines the degree of barrel distortion at the wide-angle end of the zoom lens. If the upper limit of 0.96 is exceeded, it will be difficult to reduce the size and thickness. When the lower limit of 0.7 is exceeded, when image distortion due to distortion of the optical system is corrected by image processing, the enlargement ratio in the radial direction of the view angle peripheral portion becomes too high, and the sharpness of the peripheral portion of the image is reduced. Deterioration becomes noticeable.

  In this way, the purpose of introducing distortion correction intentionally in an optical system and correcting the distortion by electrically processing the image after imaging with an electronic image sensor is to reduce the size of the optical system or increase the angle (distortion). The vertical angle of view is 38 ° or more).

  Moreover, it is more preferable to satisfy the following.

_{(1) '0.75 <y 08} * / (f W · tanω 08W) <0.95
Furthermore, it is most preferable to satisfy the following.

(1) ”0.80 <y ₀₈ ^* / (f _W · tan ω _08W ) <0.94
According to a ninth electronic imaging device of the present invention, the following conditions are satisfied in the first to eighth electronic imaging devices.

(2) 1.2 <y ₁₀ ^* / a <6.0
Where y ₁₀ ^* is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device, the unit is mm, and a is the long side of the electronic imaging device The distance between pixels in the direction, the unit is μm.

  Hereinafter, the reason and action of the ninth electronic imaging device adopting the above configuration will be described. The imaging ability of the zoom lens corresponds to the electronic imaging device that satisfies the condition (2).

  According to a tenth electronic imaging device of the present invention, the following conditions are satisfied in the first to ninth electronic imaging devices.

(3) F _W ≧ 1.1a (μm)
Here, _FW is the open F value at the wide-angle end of the zoom lens, a is the distance between pixels in the long side direction of the electronic image sensor, and the unit is μm.

  The reason and action of the above configuration in the tenth electronic imaging apparatus will be described below. In order to avoid using the optical low-pass filter as much as possible to reduce the thickness, the condition (3) should be satisfied. If this condition is satisfied, aliasing distortion can be tolerated without an optical low-pass filter. This utilizes the fact that when the pixel size is reduced to some extent, the component above the Nyquist frequency disappears due to the influence of diffraction. If the condition (3) is not satisfied, an optical low-pass filter is necessary. Therefore, in order to ensure image quality, it is better that the aperture stop is only open and not narrowed down. Then, it becomes possible to reduce the size and thickness by the amount that can eliminate the narrowing mechanism.

  Further, it is more preferable to satisfy the condition (3) ′.

(3) 'F _W ≧ 1.2a (μm)
Further, the condition (3) "is most preferable.

(3) “F _W ≧ 1.3a (μm)
The eleventh electronic imaging apparatus of the present invention is characterized in that the following conditions are satisfied in the first to tenth electronic imaging apparatuses.

(4) 0.4 <(dy ^* / dy) _{y08 *} / (dy ^* / dy) _{y00 *} <0.9
However, in the relationship between the actual image height y ^* and the ideal image height y, y ₁₀ ^* is the distance (maximum image) from the center to the farthest point in the effective imaging plane (within the imaging plane) of the electronic imaging device. and high), a differential value at _{^{(dy * / dy) y08 *}} , (dy * / dy) y00 * is high _{^{y 08 * (= 0.8 y 10}} *) and the screen center image, respectively.

Hereinafter, the reason and action of the eleventh electronic imaging apparatus having the above configuration will be described. Although the actual image height y ^* is a function of the ideal image height y, the differential value dy ^* / dy is larger than a certain level. In such a local y, the local enlargement ratio at the time of distortion correction becomes too large, and it becomes difficult to obtain a predetermined resolving power at that portion.

  If the lower limit of 0.4 of the condition (4) is not reached, the local enlargement ratio at the time of distortion correction becomes too large, and it becomes difficult to obtain a predetermined resolving power at that portion. When the upper limit of 0.9 is exceeded, it becomes difficult to achieve the object of the present invention.

  Moreover, it is more preferable to satisfy the following.

(4) ′ 0.5 <(dy ^* / dy) _{y08 *} / (dy ^* / dy) _{y00 *} <0.87
Furthermore, it is most preferable to satisfy at least the following.

(4) "0.55 <(dy ^* / dy) _{y08 *} / (dy ^* / dy) _{y00 *} <0.84
Note that the image forming ability of the zoom lens corresponds to an electronic imaging apparatus that satisfies the following condition (2).

  According to a twelfth electronic imaging device of the present invention, in the first to eleventh electronic imaging devices, the zoom lens includes, in order from the object side, a negative 1-1 lens component B1 and a positive 1-2 lens component. A first lens unit having a negative refractive power, a positive second-first lens component B21, and a negative second-second lens component B22, and having a second lens unit having a positive refractive power. The zoom lens has the electronic image pickup device in the vicinity of the image forming position, and at the time of zooming, the second lens group does not move with respect to the housing of the electronic image pickup device, and the first lens group The relative position is movable with respect to the second lens group, and the electronic imaging device is movable with respect to the housing of the electronic imaging device on the optical axis of the zoom lens. It is characterized by satisfaction.

(5) -1.2 <f _W / r _22R <0.9
(6) 0.17 <(D _12W −D _12T ) / (f _W · γ ² ) <0.33
Where r _22R is the radius of curvature of the lens surface closest to the image side in the 2-2 lens component on the optical axis, and D _12W and D _12T are the first lens group at the wide-angle end and the telephoto end of the zoom lens, respectively. The distance on the optical axis between the most image side lens surface top of the second lens unit and the most object side lens surface top of the second lens group, f _W is the focal length of the entire system at the wide angle end of the zoom lens, and γ is f _T / f _W (f _T is the focal length of the entire system at the telephoto end of the zoom lens). One component refers to a single lens, a cemented lens, or a compound lens in which a resin or the like is adhered and cured on the lens surface. That is, the number of medium boundary surfaces is one plus the number of lenses.

  The reason and action of the above configuration in the twelfth electronic imaging apparatus will be described below.

  If the upper limit of 0.9 of condition (5) is exceeded, the zoom lens retracted thickness, that is, even if the distance between the lens surface closest to the object side and the lens surface closest to the image side is thin on the optical axis, Then, it becomes thick, and after all the thickness does not decrease when retracted. Further, from the viewpoint of aberration correction, the shape of the lens surface closest to the image side of the 2-2 lens component B22 has a convex shape at the center, that is, near the optical axis, to correct astigmatism, spherical aberration, In order to correct coma aberration, it is better to use an aspherical surface whose peripheral part is concave on the image side. In this case, the relative decentering sensitivity of the 2-2 lens component B22 with the most object side lens surface is high. This is not preferable. Therefore, it is preferable that the astigmatism is corrected by the first lens group so that the lower limit of -1.2 of the condition (5) is not exceeded.

  If the upper limit of 0.33 of the condition (6) is exceeded, it is advantageous for aberration correction, but the off-axis ray height in the first lens group becomes high at the wide-angle end, and the diameter of the first lens group tends to enlarge, For this reason, the thickness of each lens component is increased, which is contrary to the purpose. If the lower limit of 0.17 is exceeded, it is advantageous for reducing the thickness, but both the first and second lens groups have to increase the refractive power, and in combination with the small number of components, each aberration can be corrected. There are problems such as difficulty and increased sensitivity to eccentricity.

  Moreover, it is more preferable to satisfy the following.

(5) ′ −1.1 <f _W / r _22R <0.7
(6) ′ 0.19 <(D _12W −D _12T ) / (f _W · γ ² ) <0.30
Furthermore, it is most preferable to satisfy the following.

(5) "-1 <f _W / r _22R <0.5
(6) ”0.21 <(D _12W −D _12T ) / (f _W · γ ² ) <0.27
According to a thirteenth electronic imaging device of the present invention, the first to twelfth electronic imaging devices satisfy the following conditions.

(7) 1.0 <ΣD _T / f _W <2.2
However, .SIGMA.D _T is the distance to the lens surface vertex of the most image side from the lens surface apex on the most object side at the telephoto end of the zoom lens.

  Hereinafter, the reason and action of the thirteenth electronic imaging device having the above configuration will be described.

  It is more preferable if the above conditions (5) and (6) are satisfied and, as a result, the following condition (7) can be satisfied.

  If the upper limit of 2.2 of this condition (7) is exceeded, the thickness when retracted is still insufficient. When the lower limit of 1.0 is exceeded, it becomes difficult to form a lens component having a predetermined refractive power.

  Moreover, it is more preferable to satisfy the following.

(7) '1.2 <ΣD _T / f _W <2.0
Furthermore, it is most preferable to satisfy the following.

(7) "1.4 <ΣD _T / f _W <1.8
A fourteenth electronic imaging device of the present invention is characterized in that, in the twelfth and thirteenth electronic imaging devices, the following conditions are satisfied.

(8) 0.1 <f _W / | f ₂₂ | <1
Here, f ₂₂ is the combined focal length of the 2-2 lens component.

  The reason and action of the above configuration in the fourteenth electronic imaging device will be described below. When the condition (8) is satisfied, the conditions (5) to (7) are easily satisfied. In particular, when considering that the condition (6) is satisfied, it is better to give the second lens group a certain level of refractive power. That is, it is better that the composite focal length of the 2-2 lens component that has the effect of canceling it is weak.

  If the upper limit of 1 of the condition (8) is exceeded, the refractive power of the second lens group becomes weak, or there are problems of deterioration of aberration and decentration sensitivity due to increasing the burden of refractive power on the 2-1 lens component. is there. Exceeding the lower limit of 0.1 tends to cause insufficient correction of each aberration (particularly longitudinal chromatic aberration).

  Moreover, it is more preferable to satisfy the following.

(8) ′ 0.2 <f _W / | f ₂₂ | <0.8
Furthermore, it is most preferable to satisfy the following.

(8) "0.3 <f _W / | f ₂₂ | <0.6
According to a fifteenth to fourteenth electronic imaging device of the present invention, the fifteenth electronic imaging device satisfies the following conditions.

(9) 35 <ν ₂₁ −ν ₂₂ <95
Where ν ₂₁ and ν ₂₂ are Abbe numbers (d-line reference) of the 2-1 lens component and 2-2 lens component, respectively.

  Hereinafter, the reason and operation of the fifteenth electronic imaging device will be described. If the upper limit 95 of the condition (9) is exceeded, there is no problem in terms of aberration, but such an optical medium does not exist. When the lower limit of 35 is exceeded, axial chromatic aberration tends to deteriorate.

  Moreover, it is more preferable to satisfy the following.

(9) '40 <ν ₂₁ −ν ₂₂ <85
Furthermore, it is most preferable to satisfy the following.

(9) ”45 <ν ₂₁ −ν ₂₂ <80
According to a sixteenth electronic imaging device of the present invention, the twelfth to fifteenth electronic imaging devices satisfy the following conditions.

(10) −0.7 <f _W / r _11F <0.2
Here, r _11F is the radius of curvature on the optical axis of the lens surface closest to the object side in the 1-1 lens component.

  According to a seventeenth electronic imaging device of the present invention, the twelfth to sixteenth electronic imaging devices satisfy the following conditions.

(11) 0.6 <t ₁ / t ₂ <1.4
Here, t ₁ and t ₂ are distances on the optical axis from the most object side surface to the most image side surface of each of the first lens group and the second lens group.

  An eighteenth electronic imaging device according to the present invention is characterized in that, in the twelfth to seventeenth electronic imaging devices, the following conditions are satisfied.

(12) 0.1 <d ₁₁ / f _W <0.5
Here, d ₁₁ is an air interval on the optical axis of the negative 1-1 lens component and the positive 1-2 lens component of the first lens group.

  According to a nineteenth electronic imaging device of the present invention, the twelfth to eighteenth electronic imaging devices satisfy the following conditions.

(13) 0.5 <R _11R / R _12F <1
Where R _11R is the radius of curvature on the optical axis of the most image-side surface of the negative 1-1 lens component of the first lens group, and R _12F is the positive 1-2 lens of the first lens group. This is the radius of curvature on the optical axis of the surface closest to the object in the component.

  Hereinafter, the reason and operation of the above-described configuration in the sixteenth to nineteenth electronic imaging devices will be described.

  The above conditions (10) to (13) are also advantageous conditions for reducing the thickness when retracted. Any one of them should be satisfied.

  When the lower limit of -0.7 of the condition (10) is exceeded, the zoom lens retracted thickness, that is, the distance between the lens surface closest to the object side and the lens surface closest to the image side is thin on the optical axis, but thick at the periphery of the lens. As a result, the thickness does not decrease when retracted. When the upper limit of 0.2 is exceeded, it is difficult to correct astigmatism.

  When the upper limit of 1.4 of the condition (11) is exceeded, the relative decentering sensitivity when each lens surface of the second lens group is formed of an aspheric surface tends to increase. If the lower limit of 0.6 is exceeded, astigmatism tends to deteriorate.

Also, reducing the air gap d ₁₁ on the optical axis of the negative of the 1-1 lens component and the positive 1-2 lens component of the first lens group for the thinner, the optimal main of the first lens group Since the point position shifts to the image side, the curvature of the surface closest to the object side of the negative lens component moves in the negative direction to return it. Then, barrel distortion or astigmatism deteriorates, but the distortion can be corrected and corrected by image processing. However, if d ₁₁ is decreased beyond the lower limit of 0.1 of condition (12), the distortion when correcting astigmatism becomes too large, and even if it is corrected by image processing, It becomes difficult to ensure the resolution. If the upper limit of 0.5 of the condition (12) is exceeded, it is difficult to make the entire lens system thinner as in the prior art.

Alternatively, d ₁₁ can be easily reduced by allowing distortion and allowing the negative lens component and the positive lens component of the first lens group in the zoom lens to satisfy the condition (13). When the upper limit value 1 of the condition (13) is exceeded, the distortion when the astigmatism is corrected becomes excessively large, and it becomes difficult to ensure the resolution at the periphery of the screen even if the correction is performed by image processing. If the lower limit of 0.5 is exceeded, it will be difficult to make the entire lens system thinner as in the prior art.

  Moreover, regarding the conditions (10) to (13), it is more preferable that the following are satisfied.

(10) ′ −0.5 <f _W / r _11F <0.15
(11) ′ 0.7 <t ₁ / t ₂ <1.3
(12) ′ 0.15 <d ₁₁ / f _W <0.4
(13) ′ 0.55 <R _11R / R _12F <0.95
Furthermore, regarding the conditions (0) to (13), it is most preferable to satisfy the following.

(10) "-0.3 <f _W / r _11F <0.1
(11) ”0.8 <t ₁ / t ₂ <1.2
(12) ”0.2 <d ₁₁ / f _W <0.3
(13) ”0.6 <R _11R / R _12F <0.9
According to a twentieth electronic imaging device of the present invention, a zoom lens system that forms an image of a subject, and a photoelectric conversion element that is disposed on the image side of the zoom lens system and converts an image by the zoom lens into an electrical signal An electronic imaging device comprising:
The zoom lens system has a finite focal length, and a fixed lens group having a reflecting surface fixed to the imaging device main body at the time of zooming,
At least one movable lens group that is arranged on the incident side or the exit side of the fixed lens group, has a finite focal length, and changes the relative positional relationship with the fixed lens group, and performs zooming;
In addition, the photoelectric conversion element changes a relative positional relationship with the fixed lens group in association with image position movement due to zooming of the zoom lens group.

  The reason and action of the above configuration in the twentieth electronic imaging apparatus will be described below.

  By fixing the lens group having the reflecting surface to the electronic imaging apparatus main body (housing), it is not necessary to move the lens group that tends to increase in volume. Thereby, it is possible to save power for zooming and to simplify a mechanical mechanism for zooming.

  In addition, the fixed lens group moves relative to the image plane as the photoelectric conversion element (electronic image pickup element) moves relative to the fixed lens group. Therefore, the fixed lens group can be handled as a group that moves relative to the image plane, which is advantageous in reducing the number of lens groups for constituting the variable power lens system. Also, the movable lens group in front of or behind the fixed lens group can be increased in the amount of movement with respect to the image plane depending on the movement method, which is advantageous in securing a zoom ratio.

  According to a twenty-first electronic imaging device of the present invention, in the twentieth electronic imaging device, only one movable lens group is arranged on an incident side of the fixed lens group having the reflecting surface, and the movable lens group is It is possible to move to a position accommodated in the lens body.

  Hereinafter, the reason and action of the above-described configuration in the twenty-first electronic imaging device will be described. As compared with the case where a plurality of movable lens groups are provided on the incident side of the fixed lens group, the lens extension amount during the photographing operation can be reduced. And since the distance to a fixed lens group and a photoelectric conversion element can be made small, the restrictions to the height direction or width direction of an imaging device can also be comprised few.

  According to a twenty-second electronic imaging device of the present invention, in the twentieth to twenty-first electronic imaging devices, the fixed lens group includes only one reflecting surface.

  Hereinafter, the reason and action of the above-described configuration in the twenty-second electronic imaging device will be described. With this configuration, the volume of the fixed lens group is reduced as compared with the case where a plurality of reflecting surfaces are provided in the fixed lens group. it can.

  According to a twenty-third electronic imaging device of the present invention, in the twentieth to twenty-second electronic imaging devices, at least one lens group in the movable lens group includes a lens component having a positive refractive power and a lens component having a negative refractive power. It is characterized by having.

  The reason and action of the above-described configuration in the twenty-third electronic imaging apparatus will be described below. This configuration is advantageous for correcting aberrations in the group.

  According to a twenty-fourth electronic imaging device of the present invention, in the twentieth to twenty-third electronic imaging devices, at least one lens group in the fixed lens group includes a lens component having a positive refractive power and a lens component having a negative refractive power. It is characterized by having.

  The reason and action of the above-described configuration in the twenty-fourth electronic imaging device will be described below. This configuration is advantageous for correcting aberrations in the group.

  According to a twenty-fifth electronic imaging device of the present invention, in the twenty-fourth to twenty-fourth electronic imaging devices, only one movable lens group is provided in the zoom lens system.

  In the following, the reason and action of the 25th electronic imaging device will be described. With this configuration, the lens driving mechanism can be simplified by using only one moving lens group in the variable magnification lens system. Can be.

  According to the present invention, even when using a zoom lens in which the total number of lens components is reduced to the limit and the imaging performance is extremely stable in the entire zoom range, An electronic imaging device having an extremely thin thickness can be obtained. Moreover, even if a fixed lens having a reflecting surface that reflects the optical path is used, the number of lens groups can be saved, and an electronic imaging device that is not disadvantageous for a high zoom ratio can be obtained.

  First, Examples 1 to 6 of the zoom lens used in the electronic imaging apparatus of the present invention will be described below. FIGS. 1 to 4 show developed lens cross-sectional views of the wide-angle end (a), the intermediate state (b), and the telephoto end (c) when focusing on an object point at infinity in Examples 1 to 6, respectively. In the figure, the first lens group is G1, the aperture stop is S, the second lens group is G2, the parallel plate constituting the low-pass filter with IR cut coat, etc. is L, and the parallel plate of the cover glass of the electronic image sensor is G. The image plane is indicated by I. In addition, a multilayer film for limiting the wavelength region may be provided on the surface of the cover glass G. Further, the cover glass G may have a low-pass filter function.

  As shown in the developed cross-sectional view of FIG. 1, the zoom lens according to the first exemplary embodiment includes, in order from the object side, a first lens group G1 having a negative refractive power, an aperture stop S, and a second lens group G2 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves along a locus convex toward the image side, and at the telephoto end is positioned closer to the image side than the wide-angle end position. The aperture stop S and the second lens group G2 move monotonously toward the object side while integrally reducing the distance between the first lens group G1.

  In order from the object side, the first lens group G1 includes a biconcave negative lens and a positive meniscus lens having a convex surface facing the object side, and the second lens group G2 has a biconvex positive lens and a convex surface facing the image side. It consists of a negative meniscus lens.

  Aspherical surfaces are used for eight of all lens surfaces.

  As shown in the developed cross-sectional view of FIG. 2, the zoom lens according to the second exemplary embodiment includes, in order from the object side, a first lens group G1 having a negative refractive power, an aperture stop S, and a second lens group G2 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves along a locus convex toward the image side, and at the telephoto end is positioned closer to the image side than the wide-angle end position. The aperture stop S and the second lens group G2 move monotonously toward the object side while integrally reducing the distance between the first lens group G1.

  In order from the object side, the first lens group G1 includes a biconcave negative lens and a positive meniscus lens having a convex surface facing the object side, and the second lens group G2 has a biconvex positive lens and a convex surface facing the image side. It consists of a negative meniscus lens.

  Aspherical surfaces are used for eight of all lens surfaces.

  As shown in the developed sectional view of FIG. 3, the zoom lens according to the third exemplary embodiment includes, in order from the object side, a first lens group G1 having a negative refractive power, an aperture stop S, and a second lens group G2 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves along a locus convex toward the image side, and at the telephoto end is positioned closer to the image side than the wide-angle end position. The aperture stop S and the second lens group G2 move monotonously toward the object side while integrally reducing the distance between the first lens group G1.

  In order from the object side, the first lens group G1 includes a biconcave negative lens and a positive meniscus lens having a convex surface facing the object side, and the second lens group G2 has a biconvex positive lens and a convex surface facing the image side. It consists of a negative meniscus lens.

  Aspherical surfaces are used for eight of all lens surfaces.

  As shown in the developed sectional view of FIG. 4, the zoom lens according to the fourth exemplary embodiment includes, in order from the object side, a first lens group G1 having a negative refractive power, an aperture stop S, and a second lens group G2 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves along a locus convex toward the image side, and at the telephoto end is positioned closer to the image side than the wide-angle end position. The aperture stop S and the second lens group G2 move monotonously toward the object side while integrally reducing the distance between the first lens group G1.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconvex positive lens, It consists of a negative meniscus lens with a convex surface facing the image side.

  The aspheric surfaces are used for the five surfaces of the image side surface of the negative meniscus lens of the first lens group G1 and all the lens surfaces of the second lens group G2.

  As shown in the developed cross-sectional view of FIG. 5, the zoom lens of Example 5 includes, in order from the object side, a first lens group G1 having a negative refractive power, an aperture stop S, and a second lens group G2 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves along a locus convex toward the image side, and at the telephoto end is positioned closer to the image side than the wide-angle end position. The aperture stop S and the second lens group G2 move monotonously toward the object side while integrally reducing the distance between the first lens group G1.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconvex positive lens, It consists of a biconcave negative lens.

  The aspheric surfaces are used for the five surfaces of the image side surface of the negative meniscus lens of the first lens group G1 and all the lens surfaces of the second lens group G2.

  As shown in the developed cross-sectional view of FIG. 6, the zoom lens of Example 6 includes, in order from the object side, a first lens group G1 having a negative refractive power, an aperture stop S, and a second lens group G2 having a positive refractive power. When zooming from the wide-angle end to the telephoto end, the first lens group G1 moves along a locus convex toward the image side, and at the telephoto end is positioned closer to the image side than the wide-angle end position. The aperture stop S and the second lens group G2 move monotonously toward the object side while integrally reducing the distance between the first lens group G1.

  In order from the object side, the first lens group G1 includes a negative meniscus lens having a convex surface facing the object side and a positive meniscus lens having a convex surface facing the object side. The second lens group G2 includes a biconvex positive lens, It consists of a biconcave negative lens.

  The aspherical surfaces are used on both surfaces of the negative meniscus lens of the first lens group G1 and all the lens surfaces of the second lens group G2.

In the following, the numerical data of each of the above embodiments is shown. Symbols are the above, f is the total focal length, _FNO is the F number, WE is the wide angle end, ST is the intermediate state, TE is the telephoto end, r ₁ , R ₂ ... Are the radii of curvature of the lens surfaces, d ₁ , d ₂ ... _Are the distances between the lens surfaces, n _d1 , n _d2 are the refractive indices of the d-line of each lens, and ν _d1 , ν _d2 . It is the Abbe number of the lens. The aspherical shape is represented by the following formula, where x is an optical axis with the light traveling direction being positive, and y is a direction orthogonal to the optical axis.

x = (y ² / r) / [1+ {1- (K + 1) (y / r) ² } ^1/2 ]
+ A ₄ y ⁴ + A ₆ y ⁶ + A ₈ y ⁸
Here, r is a paraxial radius of curvature, K is a conical coefficient, and A ₄ , A ₆ , and A ₈ are fourth-order, sixth-order, and eighth-order aspheric coefficients, respectively.

Example 1
r ₁ = -80.3012 (aspherical surface) d ₁ = 1.0000 n _d1 = 1.74320 ν _d1 = 49.34
r ₂ = 6.1213 (aspherical surface) d ₂ = 1.5886
r ₃ = 7.8091 (aspherical surface) d ₃ = 1.6298 n _d2 = 1.84666 ν _d2 = 23.78
r ₄ = 12.6372 (aspherical surface) d ₄ = (variable)
r ₅ = ∞ (aperture) d ₅ = -0.5000
r ₆ = 4.5177 (aspherical surface) d ₆ = 2.1059 n _d3 = 1.58913 ν _d3 = 61.14
r ₇ = -11.6839 (aspherical surface) d ₇ = 0.5364
r ₈ = -4.0191 (aspherical surface) d ₈ = 1.0393 n _d4 = 1.84666 ν _d4 = 23.78
r ₉ = -6.9703 (aspherical surface) d ₉ = (variable)
r ₁₀ = ∞ d ₁₀ = 0.9600 n _d5 = 1.54771 ν _d5 = 62.84
r ₁₁ = ∞ d ₁₁ = 0.6000
r ₁₂ = ∞ d ₁₂ = 0.5000 n _d6 = 1.51633 ν _d6 = 64.14
r ₁₃ = ∞ d ₁₃ = 0.5000
r ₁₄ = ∞ (image plane)
Aspheric coefficient 1st surface K = 0
A ₄ = 9.0166 × 10 ^-5
A ₆ = 0.0000
A ₈ = 0.0000
Second side K = 0
A ₄ = -4.1100 × 10 ^-4
A ₆ = 2.6370 × 10 ^-5
A ₈ = 0.0000
Third side K = 0
A ₄ = -7.3294 × 10 ^-4
A ₆ = 2.6541 × 10 ^-5
A ₈ = 0.0000
4th surface K = 0
A ₄ = -5.6865 × 10 ^-4
A ₆ = 1.6975 × 10 ^-5
A ₈ = 0.0000
6th surface K = 0
A ₄ = 5.0962 × 10 ^-4
A ₆ = 0.0000
A ₈ = 0.0000
Surface 7 K = 0
A ₄ = 3.6845 × 10 ^-3
A ₆ = 0.0000
A ₈ = 0.0000
8th surface K = 0
A ₄ = 1.3837 × 10 ^-2
A ₆ = -2.1725 × 10 ^-4
A ₈ = 0.0000
9th surface K = 0
A ₄ = 9.2372 × 10 ^-3
A ₆ = 1.5395 × 10 ^-4
A ₈ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.0061 11.9936 17.9196
F _NO 3.1351 4.3092 5.5123
d ₄ 14.5657 4.8297 1.6000
d ₉ 9.3815 13.9712 18.5540.

Example 2
r ₁ = -48.0000 (aspherical surface) d ₁ = 1.0000 n _d1 = 1.74320 ν _d1 = 49.34
r ₂ = 5.6908 (aspherical surface) d ₂ = 1.4977
r ₃ = 7.4496 (aspherical surface) d ₃ = 1.5669 n _d2 = 1.84666 ν _d2 = 23.78
r ₄ = 12.8049 (aspherical surface) d ₄ = (variable)
r ₅ = ∞ (aperture) d ₅ = -0.5000
r ₆ = 4.7641 (aspherical surface) d ₆ = 2.3639 n _d3 = 1.49700 ν _d3 = 81.54
r ₇ = -7.9339 (aspherical surface) d ₇ = 0.8763
r ₈ = -4.2374 (aspherical surface) d ₈ = 1.0952 n _d4 = 1.84666 ν _d4 = 23.78
r ₉ = -6.5441 (aspherical surface) d ₉ = (variable)
r ₁₀ = ∞ d ₁₀ = 0.9600 n _d5 = 1.54771 ν _d5 = 62.84
r ₁₁ = ∞ d ₁₁ = 0.6000
r ₁₂ = ∞ d ₁₂ = 0.5000 n _d6 = 1.51633 ν _d6 = 64.14
r ₁₃ = ∞ d ₁₃ = 0.5000
r ₁₄ = ∞ (image plane)
Aspheric coefficient 1st surface K = 0
A ₄ = 1.4590 × 10 ^-4
A ₆ = 0.0000
A ₈ = 0.0000
Second side K = 0
A ₄ = -6.5163 × 10 ^-4
A ₆ = 4.4567 × 10 ^-5
A ₈ = 0.0000
Third side K = 0
A ₄ = -8.9735 × 10 ^-4
A ₆ = 4.6463 × 10 ^-5
A ₈ = 0.0000
4th surface K = 0
A ₄ = -6.1437 × 10 ^-4
A ₆ = 3.0689 × 10 ^-5
A ₈ = 0.0000
6th surface K = 0.
A ₄ = -2.0881 × 10 ^-4
A ₆ = 0.0000
A ₈ = 0.0000
Surface 7 K = 0
A ₄ = 3.7741 × 10 ^-3
A ₆ = 0.0000
A ₈ = 0.0000
8th surface K = 0
A ₄ = 1.1838 × 10 ^-2
A ₆ = -1.4228 × 10 ^-4
A ₈ = 0.0000
9th surface K = 0
A ₄ = 7.3941 × 10 ^-3
A ₆ = 1.0081 × 10 ^-4
A ₈ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.0042 11.9902 17.9396
F _NO 3.0434 4.1365 5.2256
d ₄ 13.2974 4.5198 1.6000
d ₉ 9.4288 14.4655 19.5101.

Example 3
r ₁ = -33.6563 (aspherical surface) d ₁ = 1.0000 n _d1 = 1.74320 ν _d1 = 49.34
r ₂ = 6.2347 (aspherical surface) d ₂ = 1.4796
r ₃ = 8.8272 (aspherical surface) d ₃ = 1.6011 n _d2 = 1.82114 ν _d2 = 24.06
r ₄ = 18.7944 (aspherical surface) d ₄ = (variable)
r ₅ = ∞ (aperture) d ₅ = -0.5000
r ₆ = 4.6767 (aspherical surface) d ₆ = 2.0886 n _d3 = 1.49700 ν _d3 = 81.54
r ₇ = -6.7262 (aspherical surface) d ₇ = 0.7069
r ₈ = -3.9732 (aspherical surface) d ₈ = 1.4401 n _d4 = 1.58393 ν _d4 = 30.21
r ₉ = -9.3454 (aspherical surface) d ₉ = (variable)
r ₁₀ = ∞ d ₁₀ = 0.9600 n _d5 = 1.54771 ν _d5 = 62.84
r ₁₁ = ∞ d ₁₁ = 0.6000
r ₁₂ = ∞ d ₁₂ = 0.5000 n _d6 = 1.51633 ν _d6 = 64.14
r ₁₃ = ∞ d ₁₃ = 0.5000
r ₁₄ = ∞ (image plane)
Aspheric coefficient 1st surface K = 0
A ₄ = 1.3164 × 10 ^-4
A ₆ = 0.0000
A ₈ = 0.0000
Second side K = 0
A ₄ = -5.3057 × 10 ^-4
A ₆ = 3.3686 × 10 ^-5
A ₈ = 0.0000
Third side K = 0
A ₄ = -7.5233 × 10 ^-4
A ₆ = 2.8971 × 10 ^-5
A ₈ = 0.0000
4th surface K = 0
A ₄ = -5.1461 × 10 ^-4
A ₆ = 1.2110 × 10 ^-5
A ₈ = 0.0000
6th surface K = 0
A ₄ = -4.1026 × 10 ^-4
A ₆ = -5.9764 × 10 ^-5
A ₈ = 0.0000
Surface 7 K = 0
A ₄ = 2.7551 × 10 ^-3
A ₆ = 4.7060 × 10 ^-5
A ₈ = 0.0000
8th surface K = 0
A ₄ = 1.1630 × 10 ^-2
A ₆ = -3.4684 × 10 ^-5
A ₈ = 0.0000
9th surface K = 0
A ₄ = 7.6508 × 10 ^-3
A ₆ = 1.2631 × 10 ^-4
A ₈ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.0010 11.9974 17.9434
F _NO 3.0785 4.1576 5.2322
d ₄ 14.3857 4.7841 1.6000
d ₉ 9.2380 14.0573 18.8752.

Example 4
r ₁ = 54.1696 d ₁ = 1.0000 n _d1 = 1.74320 ν _d1 = 49.34
r ₂ = 4.8359 (aspherical surface) d ₂ = 1.6143
r ₃ = 6.5785 d ₃ = 1.6421 n _d2 = 1.84666 ν _d2 = 23.78
r ₄ = 9.7896 d ₄ = (variable)
r ₅ = ∞ (aperture) d ₅ = -0.3000
r ₆ = 4.4880 (aspherical surface) d ₆ = 2.0086 n _d3 = 1.49700 ν _d3 = 81.54
r ₇ = -5.2355 (aspherical surface) d ₇ = 0.6212
r ₈ = -4.2761 (aspherical surface) d ₈ = 2.5138 n _d4 = 1.68893 ν _d4 = 31.08
r ₉ = -12.1262 (aspherical surface) d ₉ = (variable)
r ₁₀ = ∞ d ₁₀ = 0.9600 n _d5 = 1.54771 ν _d5 = 62.84
r ₁₁ = ∞ d ₁₁ = 0.6000
r ₁₂ = ∞ d ₁₂ = 0.5000 n _d6 = 1.51633 ν _d6 = 64.14
r ₁₃ = ∞ d ₁₃ = 0.5000
r ₁₄ = ∞ (image plane)
Aspheric coefficient 2nd surface K = -0.3732
A ₄ = 1.1763 × 10 ^-4
A ₆ = 7.6055 × 10 ^-6
A ₈ = 0.0000
6th surface K = 0
A ₄ = -4.8314 × 10 ^-4
A ₆ = -1.8704 × 10 ^-5
A ₈ = 0.0000
Surface 7 K = 0
A ₄ = 5.4417 × 10 ^-3
A ₆ = -1.4828 × 10 ^-4
A ₈ = 0.0000
8th surface K = 0
A ₄ = 8.7473 × 10 ^-3
A ₆ = -2.3686 × 10 ^-4
A ₈ = 0.0000
9th surface K = 0
A ₄ = 3.8519 × 10 ^-3
A ₆ = 9.6677 × 10 ^-5
A ₈ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.0150 11.9944 17.3441
F _NO 3.1115 4.1841 5.1487
d ₄ 12.9832 4.1430 1.4000
d ₉ 8.3569 13.0706 17.3669.

Example 5
r ₁ = 105.9148 d ₁ = 1.0000 n _d1 = 1.74320 ν _d1 = 49.34
r ₂ = 4.8410 (aspherical surface) d ₂ = 1.5040
r ₃ = 7.2669 d ₃ = 1.7628 n _d2 = 1.90366 ν _d2 = 31.31
r ₄ = 13.0583 d ₄ = (variable)
r ₅ = ∞ (aperture) d ₅ = -0.3000
r ₆ = 5.0527 (aspherical surface) d ₆ = 3.9657 n _d3 = 1.49700 ν _d3 = 81.54
r ₇ = -6.2123 (aspherical surface) d ₇ = 0.2260
r ₈ = -14.5875 (aspherical surface) d ₈ = 1.0000 n _d4 = 1.68893 ν _d4 = 31.08
r ₉ = 21.9283 (aspherical surface) d ₉ = (variable)
r ₁₀ = ∞ d ₁₀ = 0.9600 n _d5 = 1.54771 ν _d5 = 62.84
r ₁₁ = ∞ d ₁₁ = 0.6000
r ₁₂ = ∞ d ₁₂ = 0.5000 n _d6 = 1.51633 ν _d6 = 64.14
r ₁₃ = ∞ d ₁₃ = 0.5000
r ₁₄ = ∞ (image plane)
Aspheric coefficient 2nd surface K = -0.5047
A ₄ = 1.6548 × 10 ^-4
A ₆ = 0.0000
A ₈ = 0.0000
6th surface K = 0
A ₄ = -9.9851 × 10 ^-4
A ₆ = 2.1369 × 10 ^-5
A ₈ = -1.3544 × 10 ^-5
Surface 7 K = 0
A ₄ = 3.6904 × 10 ^-3
A ₆ = -7.9943 × 10 ^-4
A ₈ = 3.4637 × 10 ^-5
8th surface K = 0
A ₄ = 4.5559 × 10 ^-3
A ₆ = -8.0268 × 10 ^-4
A ₈ = 2.4078 × 10 ^-5
Surface 9 K = 3.9777
A ₄ = 3.5893 × 10 ^-3
A ₆ = -1.2648 × 10 ^-4
A ₈ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.0849 11.8129 18.2441
F _NO 3.1477 4.1606 5.3101
d ₄ 14.7513 5.0376 1.4000
d ₉ 8.5302 12.8580 17.7946.

Example 6
r ₁ = 75.3593 (aspherical surface) d ₁ = 1.0000 n _d1 = 1.74320 ν _d1 = 49.34
r ₂ = 4.8561 (aspherical surface) d ₂ = 1.5218
r ₃ = 7.4430 d ₃ = 1.7503 n _d2 = 1.90366 ν _d2 = 31.31
r ₄ = 13.6272 d ₄ = (variable)
r ₅ = ∞ (aperture) d ₅ = -0.3000
r ₆ = 4.6713 (aspherical surface) d ₆ = 3.5824 n _d3 = 1.49700 ν _d3 = 81.54
r ₇ = -6.6499 (aspherical surface) d ₇ = 0.2264
r ₈ = -18.5581 (aspherical surface) d ₈ = 1.0000 n _d4 = 1.68893 ν _d4 = 31.08
r ₉ = 15.0264 (aspherical surface) d ₉ = (variable)
r ₁₀ = ∞ d ₁₀ = 0.9600 n _d5 = 1.54771 ν _d5 = 62.84
r ₁₁ = ∞ d ₁₁ = 0.6000
r ₁₂ = ∞ d ₁₂ = 0.5000 n _d6 = 1.51633 ν _d6 = 64.14
r ₁₃ = ∞ d ₁₃ = 0.5000
r ₁₄ = ∞ (image plane)
Aspheric coefficient 1st surface K = 0
A ₄ = -5.9981 × 10 ^-5
A ₆ = 0.0000
A ₈ = 0.0000
Second side K = -0.6453
A ₄ = 2.3718 × 10 ^-4
A ₆ = 0.0000
A ₈ = 0.0000
6th surface K = 0
A ₄ = -1.1120 × 10 ^-3
A ₆ = 1.0075 × 10 ^-5
A ₈ = -1.6650 × 10 ^-5
Surface 7 K = 0
A ₄ = 3.2283 × 10 ^-3
A ₆ = -7.9085 × 10 ^-4
A ₈ = 3.2257 × 10 ^-5
8th surface K = 0
A ₄ = 4.5672 × 10 ^-3
A ₆ = -7.9080 × 10 ^-4
A ₈ = 2.1571 × 10 ^-5
Surface 9 K = 13.2252
A ₄ = 3.9321 × 10 ^-3
A ₆ = -1.0714 × 10 ^-4
A ₈ = 0.0000
Zoom data (∞)
WE ST TE
f (mm) 6.0806 11.7818 18.2149
F _NO 3.1976 4.2126 5.3670
d ₄ 14.5976 4.7205 1.0000
d ₉ 8.0615 12.0938 16.7288.

  Aberration diagrams at the time of focusing on an object point at infinity in Examples 1 to 6 are shown in FIGS. In these aberration diagrams, (a) is the wide angle end, (b) is the intermediate state, (c) is the spherical aberration (SA), astigmatism (AS), distortion (DT), and lateral chromatic aberration (CC) at the telephoto end. ). In each figure, “FIY” indicates the maximum image height.

  Next, the angle of view and the parameter values related to the conditional expressions (1) to (13) in the above-described embodiments will be shown.

Conditional Example Example 1 Example 2 Example 3 Example 4
y ₁₀ ^* (maximum image height) (mm) 3.6 3.6 3.6 3.6
y ₁₀ ^* × 0.8 half angle of the corresponding <Note 1> 28.5 ° 28.3 ° 28.5 ° 27.6 °
Half angle of view compatible with y ₁₀ ^* x 0.6 <Note 1> 21.0 ° 20.9 ° 21.0 ° 20.6 °
WE half angle of view <Note 2> 32.6 ° 32.5 ° 32.6 ° 32.1 °
ST half angle of view 17.1 ° 17.1 ° 17.1 ° 17.0 °
TE half angle of view 11.4 ° 11.4 ° 11.4 ° 11.7 °
y ₀₈ ^* / (f _W · tanω _08W ) <Note 1> 0.88479 0.89253 0.88434 0.91714
a (μm) 2.25 2.25 2.25 2.25
y ₁₀ ^* / a 1.6 1.6 1.6 1.6
F _W / a 1.39 1.35 1.37 1.38
( _Dy ^* / dy) _{y08 *} 0.69665 0.70875 0.68859 0.78037
( _Dy ^* / dy) _{y00 *} 1 1 1 1
f _W / r _22R -0.86167 -0.91750 -0.64213 -0.49603
(D _12W −D _12T ) / (f _W · γ ² ) 0.24251 0.21824 0.23831 0.23161
ΣD _T / f _W 1.49848 1.58222 1.56912 1.74564
f _W / | f ₂₂ | 0.44920 0.33083 0.45689 0.54541
ν ₂₁ −ν ₂₂ 37.36 57.76 51.33 50.46
f _W / r _11F -0.07479 -0.12509 -0.17830 +0.11104
t ₁ / t ₂ 1.14584 0.93754 0.96342 0.82752
d ₁₁ / f _W 0.26450 0.24944 0.24656 0.26838
R _11R / R _12F 0.78387 0.76391 0.70631 0.73511
.

Conditional Example Example 5 Example 6
y ₁₀ ^* (maximum image height) (mm) 3.6 3.6
Half angle of view compatible with y ₁₀ ^* × 0.8 <Note 1> 27.0 ° 27.0 °
Half angle of view corresponding to y ₁₀ ^* × 0.6 <Note 1> 20.3 ° 20.3 °
WE half angle of view <Note 2> 31.7 ° 31.7 °
ST half angle of view 17.2 ° 17.2 °
TE half angle of view 11.2 ° 11.1 °
y ₀₈ ^* / (f _W · tanω _08W ) <Note 1> 0.92863 0.93045
a (μm) 2.25 2.25
y ₁₀ ^* / a 1.6 1.6
F _W / a 1.40 1.42
( _Dy ^* / dy) _{y08 *} 0.81886 0.82344
( _Dy ^* / dy) _{y00 *} 1 1
f _W / r _22R +0.27749 +0.40466
(D _12W −D _12T ) / (f _W · γ ² ) 0.24408 0.24920
ΣD _T / f _W 1.73688 1.61007
f _W / | f ₂₂ | 0.48760 0.51455
ν ₂₁ −ν ₂₂ 50.46 50.46
f _W / r _11F +0.05745 +0.08069
t ₁ / t ₂ 0.82185 0.88839
d ₁₁ / f _W 0.24717 0.25027
R _11R / R _12F 0.66617 0.65244
<Note 1> Calculated before distortion correction.
<Note 2> Although the half angle of view corresponding to the maximum image height y ₁₀ ^* includes a value including distortion, in each embodiment, it is assumed that distortion is corrected by image processing near the wide angle end. Therefore, the corrected half angle of view is shown. In the correction, the half angle of view corresponding to y ₁₀ ^* × 0.6 is substantially unchanged before and after the correction.

  In each of the first to sixth embodiments, the reflecting surface that bends the optical path is, for example, from the image side surface of the negative lens (negative meniscus lens or biconcave negative lens) of the second lens group G2 to the image side. It is arranged at a position of 4 mm.

  In Examples 1 to 6, the aperture stop S disposed on the object side of the positive lens (biconvex positive lens) of the second lens group G2 is a circular aperture having a fixed aperture shape, and determines the axial luminous flux. The edge portion to be positioned is located closer to the image side than the surface top position of the object side surface of the positive lens (biconvex positive lens) of the second lens group G2. With this configuration, the relative movement range of the first lens group G1 used for zooming can be increased, which is advantageous for increasing the zoom ratio or reducing the camera thickness during wide-angle shooting. Further, even when the lens barrel is retracted, it is advantageous for reducing the thickness of the lens system in the thickness direction.

  In these examples, the light amount adjustment at the time of photographing is performed by a mechanical shutter disposed on the image side of the negative lens (negative meniscus lens or biconcave negative lens) of the second lens group G2 (see FIG. 13). Of course, instead of using this mechanical shutter, a method of adjusting the photographing time used for photographing with the electronic image sensor may be used. As a result, the mechanical shutter can be omitted, which is advantageous in reducing the thickness when retracted.

  In addition, focusing on a short-distance object point in the first to sixth embodiments can be performed by moving the first lens group G1 toward the object side or moving the electronic imaging element away from the reflecting surface.

  The zoom lens used in the electronic image pickup apparatus of the present invention is an example of a zoom lens having a two-group configuration including a first lens group having a negative refractive power and a second lens group having a positive refractive power as in the first to sixth embodiments. As described above, the zoom lens used in the electronic imaging apparatus of the present invention is not limited to such a two-group configuration.

  For example, a positive lens group may be disposed on the object side of the negative lens group in the configuration of the type of the above embodiment. Alternatively, the positive lens group may be arranged on the image side of the positive lens group.

Also,
A first lens unit having a positive refractive power that is fixed with respect to the image pickup apparatus body at the time of zooming;
A second lens unit having negative refractive power that is movable during zooming,
A third lens unit having a positive refractive power that also has a reflecting surface fixed to the imaging device body at the time of zooming;
A fourth lens unit having a positive refractive power that is movable integrally with the image pickup element at the time of zooming;
A zoom lens having a four-group configuration may be used.

Also,
A first lens unit having a negative refractive power and having a reflecting surface fixed to the imaging device body at the time of zooming;
A second lens group having positive refractive power that is movable during zooming,
A zoom lens having a two-group configuration may be used.

Also,
A first lens unit having a positive or negative refractive power and having a reflecting surface fixed to the imaging device at the time of zooming;
A movable second lens group having a refractive power opposite to that of the first lens group;
A movable third lens group having positive or negative refractive power;
It is good also as a structure provided with.

  In the zoom lens used in the electronic imaging apparatus of the present invention, the configuration of various lens systems can be changed within the range described in this specification.

  The electronic image pickup apparatus of the present invention is arranged such that the optical path of the zoom lens as described above is bent through a deflection element, and a part of the zoom lens is retracted into the image pickup apparatus main body when not in use. is there. FIG. 13 shows a comparison between the conventional retracting system and the retracting system of the present invention. In this figure, the zoom lens of Example 4 is used. 13A is a cross-sectional view at the wide-angle end in the case of the conventional retracting method, FIG. 13B is a cross-sectional view at the time of the conventional retracting, and FIGS. Sectional views at the wide-angle end, the intermediate state, and the telephoto end in the case of the retracting method, (d) is a sectional view at the time of retracting according to the present invention. In the figure, reference numeral 10 denotes a camera body (housing), 11 denotes an electronic image sensor, 12 denotes a shutter mechanism, and M denotes a mirror (plane mirror). In the figure, examples of actual dimensions are shown.

  In the conventional example, as shown in FIG. 13B, the negative first lens group G1 and the positive second lens group G2 are moved to the image side along the optical axis and retracted. Therefore, when retracted, the negative first lens group G1, the positive second lens group G2 (integrated with the diaphragm S), the shutter mechanism 12, the low-pass filter L, the image sensor cover glass G, the electronic image sensor (CCD or C-MOS) ) 11 are arranged side by side in the camera body 10, the thickness of the camera body 10 that accommodates them increases in the optical axis direction.

  On the other hand, in the present invention, as shown in FIGS. 13C-1 to 13C-3, in the photographing state, positive refraction having a first lens group G1 having a negative refractive power and a mirror (reflection surface) M is provided. The magnification is changed by changing the relative distance between the second lens group G2 and the force. At this time, the positive second lens group G2 is fixed to the camera body 10, and the first lens group G1 moves along the optical axis on the incident side of the second lens group G2. The second lens group G2 has a diaphragm S fixed to the camera body 10, a positive lens, a negative lens, a shutter mechanism 12, and a mirror M fixed to the camera body 10 at the time of zooming. The optical path is bent 90 °.

  In the reflection direction of the mirror M, a low-pass filter L, a cover glass G, and an electronic image sensor 11 that move integrally along the optical axis are arranged. These elements move along the optical axis reflected by the mirror M, and their positions are determined in accordance with the movement of the image plane position due to the movement of the first lens group G1.

  In the retracting operation, as shown in FIG. 13D, the mirror M is retracted along the shape of the camera body 10, and the aperture S, the positive lens, the negative lens, and the shutter mechanism of the second lens group G2 are retracted into the retracted space. 12 is retracted so that the first lens group G1 is retracted into the camera body 10 with a distance from the second lens group G2.

  Therefore, in the present invention (FIG. 13 (d)), the thickness of the camera body 10 that houses each lens group can be made thinner than in the conventional retractable system (FIG. 13 (b)).

  By the way, the zoom lens used in the electronic imaging apparatus of the present invention is not limited to the above, and may further have the following group arrangement and movement locus. 14 to 18, the solid line represents the wide-angle end position, and the broken line represents the telephoto end position. The lens group is indicated by a thin symbol, and the movement locus is indicated by an arrow from the wide angle end (W) to the telephoto end (T).

  In the zoom lens of the embodiment of FIG. 14, in order from the object side, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, and the reflecting surface M are held. The third lens group G3 is fixed and has a positive refractive power, and the electronic imaging device 11 whose distance from the third lens group G3 changes when zooming. Then, zooming is performed by changing the interval between the lens groups.

  The third lens group G3 having the reflecting surface M has refractive power in the front and rear directions with the reflecting surface M interposed therebetween. In this example, the third lens group G3 includes a 3-1 sub lens group G3-1 having positive refractive power, a right-angle prism P, and a 3-2 sub lens group G3-2 having positive refractive power.

  The movement of the lens group and the image sensor will be described in more detail. The first lens group G1 is fixed with respect to the camera body at the time of zooming. The second lens group G2 moves in the direction approaching the reflecting surface M along the optical axis from the wide-angle end to the telephoto end with respect to the camera body. The third lens group G3 is fixed with respect to the camera body.

  The electronic imaging device (image plane) 11 moves in the direction away from the reflecting surface M along the optical axis from the wide-angle end to the telephoto end. The first lens group G1 may be movable during zooming.

  In the case of the zoom lens of the embodiment of FIG. 15, in order from the object side, the first lens group G1 having negative refractive power and the reflecting surface M are fixed to the camera body when zooming, and the first lens group having positive refractive power. A second lens group G2, a third lens group G3 having a positive refractive power, and an electronic image pickup device 11 in which the distance from the second lens group G2 changes when zooming. Then, zooming is performed by changing the interval between the lens groups.

  The second lens group G2 having the reflective surface M has refractive power only on the object side of the reflective surface M. In this example, the second lens group G2 includes a 2-1 sub lens group G2-1 having a positive refractive power and a surface mirror having a plane reflecting surface M.

  The movement of the lens group and the image sensor will be described in more detail. At the time of zooming, the first lens group G1 moves in the direction approaching the reflecting surface M along the optical axis from the wide-angle end to the telephoto end relative to the camera body. The second lens group G2 is fixed with respect to the camera body. The third lens group G3 moves in the direction away from the reflecting surface M along the optical axis from the wide-angle end to the telephoto end.

  The electronic imaging device (image plane) 11 moves in the direction away from the reflecting surface M along the optical axis from the wide-angle end to the telephoto end. The distance between the third lens group G3 and the electronic image sensor 11 is constant during zooming. Note that the interval between the third lens group G3 and the electronic image sensor 11 may be variable at the time of zooming.

  In the case of the zoom lens of the embodiment of FIG. 16, in order from the object side, the first lens group G1 having a positive refractive power, the second lens group G2 having a negative refractive power, and the reflecting surface M are held. The third lens group G3 is fixed and has positive refractive power, the fourth lens group G4 whose distance from the third lens group G3 changes when zooming, and the distance from the third lens group G3 when zooming changes. The electronic imaging device 11 is provided. Then, zooming is performed by changing the interval between the lens groups.

  The third lens group G3 having the reflecting surface M has refractive power in the front and rear directions with the reflecting surface M interposed therebetween. In this example, the third lens group G3 includes a 3-1 sub lens group G3-1 having a positive refractive power, a surface mirror having a plane reflecting surface M, and a 3-2 sub lens group G3-2 having a positive refractive power. It is configured.

  The movement of the lens group and the image sensor will be described in more detail. The first lens group G1 is fixed with respect to the camera body at the time of zooming. The second lens group G2 moves in the direction approaching the reflecting surface M along the optical axis from the wide-angle end to the telephoto end with respect to the camera body. The third lens group G3 is fixed with respect to the camera body. The fourth lens group G4 and the electronic image sensor 11 move in a direction away from the reflecting surface M along the optical axis as a unit from the wide-angle end to the telephoto end. The first lens group G1 may be movable during zooming. Further, the interval between the fourth lens group G4 and the electronic imaging element 11 may be changed upon zooming.

  In the case of the zoom lens of the embodiment of FIG. 17, in order from the object side, the first lens group G1 having a reflecting surface M and fixed to the camera body when zooming and having negative refractive power, A second lens group G2 having a positive refractive power whose distance from one lens group G changes, and an electronic imaging element 11 whose distance from the first lens group G1 changes when zooming is performed. Then, zooming is performed by changing the distance between the first lens group G1 and the second lens group G2.

  The first lens group G1 having the reflecting surface M has a negative refractive power on the object side of the reflecting surface M. In this example, the first lens group G1 includes a first-first sub lens group G1-1 having negative refractive power and a right-angle prism P.

  The movement of the lens group and the image sensor will be described in more detail. The first lens group G1 is fixed with respect to the camera body at the time of zooming. The second lens group G2 moves in the direction approaching the reflecting surface M along the optical axis from the wide-angle end to the telephoto end with respect to the camera body.

  The electronic image sensor 11 moves away from the wide-angle end to the telephoto end after approaching the reflecting surface M.

  In the case of the zoom lens of the embodiment of FIG. 18, in order from the object side, the first lens group G1 having a reflecting surface M and fixed to the camera body when zooming and having positive refractive power, A second lens group G2 having a negative refractive power whose distance from the first lens group G1 changes; a third lens group G3 having a positive refractive power that is fixed with respect to the camera body at the time of zooming; a first lens at the time of zooming It has the 4th lens group G4 and the electronic image pick-up element 11 from which the distance with a group changes. Then, zooming is performed by changing the interval between the lens groups.

  The first lens group G1 having the reflecting surface M has negative refracting power on the object side of the reflecting surface M and positive refracting power on the reflecting side. In this example, the first lens group G1 is composed of a first-first sub lens group G1-1 having a negative refractive power, a right-angle prism P, and a first-second sub-lens group G1-2 having a negative refractive power.

  The movement of the lens group and the image sensor will be described in more detail. The first lens group G1 is fixed with respect to the camera body at the time of zooming. The second lens group G2 moves in the direction away from the reflecting surface M along the optical axis from the wide-angle end to the telephoto end with respect to the camera body. The third lens group G3 is fixed with respect to the camera body. The fourth lens group G4 and the electronic image pickup device 11 move from the wide-angle end to the telephoto end in a direction away from the reflecting surface M while changing the mutual interval. The third lens group G3 may be movable during zooming. Further, the fourth lens group G4 and the electronic image pickup device 11 may be integrally moved.

  14 to 18, the lens group is schematically indicated by a thin symbol, but the lens configuration in the group is for miniaturization and balance aberration correction. A configuration including a single lens, a plurality of positive lenses or a plurality of negative lenses, and a positive lens and a negative lens may be adopted. Further, although illustrations of the aperture, shutter, low-pass filter, etc. are omitted, these may be arranged at predetermined positions as appropriate from the viewpoint of miniaturization and aberration correction. In addition, an optical element having a reflecting surface M (for example, a right-angle prism P) may have a refractive power.

  The zoom lens used in the electronic imaging apparatus of the present invention is not limited to the above, and various modifications can be made within the scope of the claims.

  19 to 21 are conceptual diagrams of the configuration of the digital camera according to the present invention in which the zoom lens as described above is incorporated in the photographing optical system 41. FIG. 19 is a front perspective view showing the appearance of the digital camera 40, FIG. 20 is a rear front view thereof, and FIG. 21 is a schematic perspective plan view showing the configuration of the digital camera 40. However, in FIGS. 19 and 21, the photographing optical system 41 is not retracted. In this example, the digital camera 40 includes a photographing optical system 41 having a photographing optical path 42, a finder optical system 43 having a finder optical path 44, a shutter button 45, a flash 46, a liquid crystal display monitor 47, a focal length change button 61, When the photographing optical system 41 is retracted, including the setting change switch 62, the photographing optical system 41, the finder optical system 43, and the flash 46 are covered with the cover 60 by sliding the cover 60. When the cover 60 is opened and the camera 40 is set to the shooting state, the shooting optical system 41 enters the non-collapsed state of FIG. 21. When the shutter button 45 disposed on the upper side of the camera 40 is pressed, shooting is performed in conjunction therewith. Photographing is performed through the optical system 41, for example, the zoom lens of the first embodiment. An object image formed by the photographic optical system 41 is formed on the imaging surface of the CCD 49 via a low-pass filter LF subjected to IR cut coating and a cover glass CG. The object image received by the CCD 49 is displayed as an electronic image on the liquid crystal display monitor 47 provided on the back of the camera via the processing means 51. Further, the processing means 51 is connected to a recording means 52 so that a photographed electronic image can be recorded. The recording means 52 may be provided separately from the processing means 51, or may be configured to perform recording / writing electronically using a floppy disk, memory card, MO, or the like. Further, it may be configured as a silver salt camera in which a silver salt film is arranged in place of the CCD 49.

  Further, a finder objective optical system 53 is disposed on the finder optical path 44. The finder objective optical system 53 includes a plurality of lens groups (three groups in the figure) and two prisms. The finder objective optical system 53 includes a zoom optical system whose focal length changes in conjunction with the zoom lens of the photographing optical system 41. The object image formed by the finder objective optical system 53 is formed on the field frame 57 of the erecting prism 55 that is an image erecting member. Behind the erecting prism 55 is an eyepiece optical system 59 that guides the erect image to the observer eyeball E. A cover member 50 is disposed on the exit side of the eyepiece optical system 59.

  In the digital camera 40 configured in this manner, the photographing optical system 41 has a high performance and a small size and can be retracted, so that a high performance and a small size can be realized.

  As shown in the figure, the optical path may be bent in the short side direction in addition to the long side direction of the imaging surface.

FIG. 3 is a lens cross-sectional view at the wide-angle end (a), an intermediate state (b), and a telephoto end (c) when focusing on an object point at infinity according to the first exemplary embodiment of the zoom lens used in the electronic imaging device of the present invention. FIG. 6 is a lens cross-sectional view similar to FIG. 1 of a zoom lens according to Embodiment 2. FIG. 6 is a lens cross-sectional view similar to FIG. 1 of a zoom lens according to Example 3. FIG. 6 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to a fourth exemplary embodiment. FIG. 6 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to a fifth exemplary embodiment. FIG. 6 is a lens cross-sectional view similar to FIG. 1 illustrating a zoom lens according to Example 6; FIG. 6 is an aberration diagram for Example 1 upon focusing on an object point at infinity. FIG. 6 is an aberration diagram for Example 2 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 3 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 4 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 5 upon focusing on an object point at infinity. FIG. 10 is an aberration diagram for Example 6 upon focusing on an object point at infinity. It is a figure which shows the comparison with the retractable system of the conventional and the retractable system of this invention. It is a figure which shows the group arrangement | positioning of another Example of a zoom lens used for the electronic imaging device of this invention, and a movement locus | trajectory. It is a figure which shows the group arrangement | positioning of another Example of a zoom lens used for the electronic imaging device of this invention, and a movement locus | trajectory. It is a figure which shows the group arrangement | positioning of another Example of a zoom lens used for the electronic imaging device of this invention, and a movement locus | trajectory. It is a figure which shows the group arrangement | positioning of another Example of a zoom lens used for the electronic imaging device of this invention, and a movement locus | trajectory. It is a figure which shows the group arrangement | positioning of another Example of a zoom lens used for the electronic imaging device of this invention, and a movement locus | trajectory. It is a front perspective view which shows the external appearance of the digital camera by this invention. FIG. 20 is a rear perspective view of the digital camera of FIG. 19. It is sectional drawing of the digital camera of FIG.

Explanation of symbols

G1 ... 1st lens group G2 ... 2nd lens group G3 ... 3rd lens group G4 ... 4th lens group G1-1 ... 1-1 sub lens group G1-2 ... 1-2 sub lens group G2-1 ... 2-1 sub lens group G3-1 ... 3-1 sub lens group G3-2 ... 3-2 sub lens group S ... Aperture stop L ... Low pass filter G ... Cover glass I ... Image plane E ... Observer eyeball F ... Optical low-pass filter M ... Mirror (plane mirror)
P ... right angle prism 10 ... camera body (housing)
DESCRIPTION OF SYMBOLS 11 ... Electronic imaging device 12 ... Shutter mechanism 40 ... Digital camera 41 ... Shooting optical system 42 ... Shooting optical path 43 ... Viewfinder optical system 44 ... Viewfinder optical path 45 ... Shutter button 46 ... Flash 47 ... Liquid crystal display monitor 49 ... CCD
DESCRIPTION OF SYMBOLS 50 ... Cover member 51 ... Processing means 52 ... Recording means 53 ... Viewfinder objective optical system 55 ... Erect prism 57 ... Field frame 59 ... Eyepiece optical system 60 ... Cover 61 ... Focal length change button 62 ... Setting change switch

Claims (14)

In an electronic imaging apparatus comprising a plurality of lens groups, a zoom lens that performs zooming by changing an interval between the plurality of lens groups, and an electronic imaging device disposed on the image side of the zoom lens,
The zoom lens includes a deflection element that deflects an optical axis, and the deflection element is fixed to the imaging apparatus main body at the time of zooming,
The first lens group, which is one of the plurality of lens groups, is a transmissive lens group that does not have a reflecting surface, is disposed closer to the object side than the deflecting element, and is at the time of zooming The distance to the deflection element changes,
The electronic image sensor changes the distance between the deflection element at the time of zooming ,
And a second lens group which is disposed on the object side of the first lens group on the object side relative to the deflection element and fixed to the imaging apparatus body together with the deflection element at the time of zooming and focusing,
The deflection element is a mirror;
The mirror is arranged so that its normal line is inclined with respect to the incident-side optical axis in order to bend the optical path at the time of zooming, and when the zoom lens is retracted into the imaging apparatus body, the mirror is movable, and the first lens An electronic imaging apparatus characterized in that a group is housed together with the second lens group . 2. The electronic imaging apparatus according to claim 1, wherein the mirror moves so as to be substantially perpendicular or substantially parallel to the optical axis of the first lens group or the normal of the effective imaging surface of the electronic imaging device. The electronic image pickup device can process image data obtained by picking up an image formed through the zoom lens with the electronic image pickup device and output the processed image data as image data having a changed shape. 3. The electronic imaging apparatus according to claim 1, wherein the following condition is satisfied when the zoom lens is focused on any object distance of 50 times or more of f _W : 3.
(1) 0.7 <y ₀₈ ^* / (f _W · tan ω _08W ) <0.96
However, f _W is the focal length of the entire system at the wide-angle end of the zoom lens, and the distance (maximum image) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device. If y ₁₀ ^* is high, y ₀₈ ^* = 0.8 y ₁₀ ^* , ω _08W is the optical axis in the object direction corresponding to the image point connecting from the center on the imaging surface at the wide-angle end to the position of y ₀₈ ^* Is an angle with respect to. Electronic imaging device according to any one of claims 1 to 3, characterized by satisfying the following condition.
(2) 1.2 <y ₁₀ ^* / a <6.0
Where y ₁₀ ^* is the distance (maximum image height) from the center to the farthest point in the effective imaging plane (in the plane where imaging is possible) of the electronic imaging device, the unit is mm, and a is the long side of the electronic imaging device The distance between pixels in the direction, the unit is μm. Electronic imaging device according to any one of claims 1, characterized by satisfying the following condition 4.
(3) F _W ≧ 1.1a (μm)
Here, _FW is the open F value at the wide-angle end of the zoom lens, a is the distance between pixels in the long side direction of the electronic image sensor, and the unit is μm. Electronic imaging device according to any one of claims 1-5, characterized in that the following condition is satisfied.
(4) 0.4 <(dy ^* / dy) _{y08 *} / (dy ^* / dy) _{y00 *} <0.9
However, in the relationship between the actual image height y ^* and the ideal image height y, y ₁₀ ^* is the distance (maximum image) from the center to the farthest point in the effective imaging plane (within the imaging plane) of the electronic imaging device. and high), a differential value at _{^{(dy * / dy) y08 *}} , (dy * / dy) y00 * is high ^{_{y 08 * (= 0.8 y 10}} *) and the screen center image, respectively. The zoom lens includes, in order from the object side, a negative first-first lens component B1 and a positive first-second lens component B12, and includes a first lens unit having negative refractive power and a positive second-1 It has a second lens group having a positive refractive power, which includes a lens component B21 and a negative second-second lens component B22, and has the electronic image sensor in the vicinity of the image forming position of the zoom lens. At the time of doubling, the second lens group does not move with respect to the housing of the electronic imaging device, the first lens group can move relative to the second lens group, and the electronic imaging device There is movable along the optical axis of the zoom lens with respect to the casing of the electronic imaging device, an electronic imaging device according to any one of claims 1 to 6, characterized in that the following condition is satisfied .
(5) -1.2 <f _W / r _22R <0.9
(6) 0.17 <(D _12W −D _12T ) / (f _W · γ ² ) <0.33
Where r _22R is the radius of curvature of the lens surface closest to the image side in the 2-2 lens component on the optical axis, and D _12W and D _12T are the first lens group at the wide-angle end and the telephoto end of the zoom lens, respectively. The distance on the optical axis between the most image side lens surface top of the second lens unit and the most object side lens surface top of the second lens group, f _W is the focal length of the entire system at the wide angle end of the zoom lens, and γ is f _T / f _W (f _T is the focal length of the entire system at the telephoto end of the zoom lens). One component refers to a single lens, a cemented lens, or a compound lens in which a resin or the like is adhered and cured on the lens surface. That is, the number of medium boundary surfaces is one plus the number of lenses. Electronic imaging device according to any one of 7 claim 1, characterized in that the following condition is satisfied.
(7) 1.0 <ΣD _T / f _W <2.2
However, .SIGMA.D _T is the distance to the lens surface vertex of the most image side from the lens surface apex on the most object side at the telephoto end of the zoom lens. Electronic imaging apparatus according to claim 7 or 8 further characterized in that the following condition is satisfied.
(8) 0.1 <f _W / | f ₂₂ | <1
Here, f ₂₂ is the combined focal length of the 2-2 lens component. Electronic imaging device according to any one of claims 7 to 9, characterized in that the following condition is satisfied.
(9) 35 <ν ₂₁ −ν ₂₂ <95
Where ν ₂₁ and ν ₂₂ are Abbe numbers (d-line reference) of the 2-1 lens component and 2-2 lens component, respectively. Electronic imaging apparatus according to any one of claims 7 to 10, characterized in that the following condition is satisfied.
(10) −0.7 <f _W / r _11F <0.2
Here, r _11F is the radius of curvature on the optical axis of the lens surface closest to the object side in the 1-1 lens component. Electronic imaging apparatus according to any one of claims 7 to 11, characterized by satisfying the following condition.
(11) 0.6 <t ₁ / t ₂ <1.4
Here, t ₁ and t ₂ are distances on the optical axis from the most object side surface to the most image side surface of each of the first lens group and the second lens group. Electronic imaging device according to any one of claims 7 to 12, characterized in that the following condition is satisfied.
(12) 0.1 <d ₁₁ / f _W <0.5
Here, d ₁₁ is an air interval on the optical axis of the negative 1-1 lens component and the positive 1-2 lens component of the first lens group. Electronic imaging apparatus according to any one of claims 7 to 13, characterized by satisfying the following condition.
(13) 0.5 <R _11R / R _12F <1
Where R _11R is the radius of curvature on the optical axis of the most image-side surface of the negative 1-1 lens component of the first lens group, and R _12F is the positive 1-2 lens of the first lens group. This is the radius of curvature on the optical axis of the surface closest to the object in the component.

Images