JP2001268583A - Image pickup device and image pickup optical system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical system capable of reproducing a satisfactory image including colors with a simple configuration and especially suitable for making a digital camera high in the number of pixels, low in cost and small in size. SOLUTION: The image pickup device is provided with an electronic image pickup device 3 satisfying the following conditional expression (1) when diagonal length of effective image pickup area is defined as d, a center interval of horizontal pixels is defined as p and having a complementary color filter composed of at least four kinds of color filters, an image pickup optical system 1 having the following spectral characteristics (2), (3) when transmittance of 400 nm is defined as T400, transmittance of 600 nm is defined as T600, transmittance of 700 nm is defined as T700 and guiding a light flux from the side of an object to the electronic image pickup device 3 and a controller 4 for performing a signal processing and an image processing based on output from the electronic image pickup device 3. (1) 1.0×10-4<p/d<6.0×10-4, (2) 8×T700<T600, (3) T400<T600.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image pickup apparatus and an image pickup optical system, and more particularly to an image pickup apparatus and an image pickup optical system using an electronic image pickup device such as a CCD.

[0002]

2. Description of the Related Art In recent years, digital cameras have become higher in pixel count, lower in price and smaller in size, and the demand for higher performance, smaller size, higher functions such as zooming, and lower cost of imaging optical systems has increased. I have. In particular, to increase the number of pixels and reduce the size, it is necessary to reduce the area of each pixel of the image sensor. This requires increasing the amount of light photoelectrically converted by the image sensor per unit area. That is, the S / N ratio is made advantageous,
This is a requirement to maintain sensitivity to a dark subject and to shorten the exposure time.

In order to obtain a color image, a color filter having a filter arrangement as shown in FIGS. 2 and 3 is arranged on an image sensor so as to have three or more photoelectric conversion elements having different wavelength characteristics. FIG. 2 shows a type called a primary color filter, which includes red (R), green (G), and blue (B) filters. FIG. 4 shows the respective wavelength characteristics. FIG. 3 shows a type called a complementary color filter, which includes cyan (C), magenta (M), yellow (Y _e ), and green (G).
Consisting of filters. FIG. 5 shows an example of each wavelength characteristic. In the case of a complementary color filter, the following processing is performed by the controller 4 (FIG. 1), and a luminance signal Y = | G + M + _Ye + C | * 1/4 color signal RY = | (M + _Ye )-(G + C) | BY = | (M + C)-(G + Y _e ) |

Neither the primary color filter nor the complementary color filter has sensitivity characteristics to the human eye, and an IR cut filter (infrared cut filter) for cutting light having a wavelength of about 700 nm or more, which has sensitivity characteristics to an image sensor, is an optical system. Are located in Many IR cut filters cut a wavelength of 700 nm or more. For example, as shown in FIG.
The transmittance around nm was degraded.

[0005] The primary color filter is easy to process for reproducing colors. The complementary color filter adds a process of converting to R, G, and B.
When converted into G and B, a blue wavelength range (40 in FIG. 11)
R for an input of about 0 nm to 430 nm).
An output of a signal (a signal that causes red coloring) is generated.

[0006] For this reason, high-pixel, high-quality digital cameras mainly use primary color filters. In an imaging device in which chromatic aberration hardly occurs, a complementary color filter may be used. When chromatic aberration is unlikely to occur, the number of pixels is small (not high), and when the aberration of the taking lens is unlikely to affect image quality, or when the F-number is darkened, or when the zoom lens is used, the magnification of the zoom lens is reduced. The use of an expensive or poorly productive (eg, fluorite) glass material, an increase in the number of lens elements used in the imaging optical system, and an increase in the length of the optical system, etc. This is the case where the chromatic aberration of itself is reduced.

Further, the primary color filter is easy to process for reproducing colors, but has a small amount of light entering each pixel (because the wavelength range of light entering each pixel is narrow). Green (light in a wavelength range of about 500 nm to 550 nm) is a major factor that determines the resolution of an image.
The primary color filter has a sensitivity to G only, and therefore the primary color filter sets the ratio of R, G, and B pixels to 1: 2: 1, and sets the ratio of pixels that greatly influence the determination of image resolution. The ratio is set to 50%.

On the other hand, in order to achieve high performance, it is necessary to enhance the imaging performance over the entire wavelength range of the light receiving sensitivity of the system. Here, a change in the imaging performance due to the wavelength is referred to as chromatic aberration. In general, chromatic aberration is corrected using the fact that the rate of change (dispersion) of the refractive index with respect to wavelength differs for each material. For example, in the case of an optical system having a positive focal length, chromatic aberration is corrected by using a material having a small dispersion for an optical element having a positive refractive power and a material having a large dispersion for an optical element having a negative refractive power. When chromatic aberration is corrected by combining optical elements as described above, not only chromatic aberration but also the imaging performance of the entire image plane must be taken into account, and measures such as increasing the number of optical elements are taken. In a zoom lens system that changes the focal length of the entire system by changing the interval between a plurality of lens groups including a lens group having a positive focal length and a lens group having a negative focal length, a more complex combination of optical elements is required. Required. At this time, when a refractive optical element (lens) is formed of glass or plastic material, there is a difference depending on the material, but as the wavelength changes from a long wavelength to a short wavelength, the refractive index increases, and the degree of the change is further increased. Becomes intense.

FIG. 24 shows the refraction by wavelength when a single lens having a refractive power (reciprocal of the focal length) of 1 at a wavelength of 550 nm is made of a typical glass material and a material called ultra-low dispersion glass. It is a figure showing change of force. FIG. 25 is a diagram showing a shift amount of a rear focal position with respect to a wavelength of an optical system including only a general refraction optical element with reference to 500 nm, where the horizontal axis represents wavelength and the vertical axis represents shift amount. It is. As can be seen from FIG. 24, the refractive optical element is a refractive optical element made of a material within a practical range because the change in power with respect to wavelength is the same for both ordinary materials and ultra-low dispersion materials. The axial chromatic aberration of the configured imaging optical system is V-shaped as shown in FIG. 25, and an image is formed at the same point only at two wavelengths, and the chromatic aberration is large on the short wavelength side and the long wavelength side. In particular, the chromatic aberration changes drastically on the short wavelength side. It has been proposed to use special glasses such as fluorite or ultra-low dispersion glass in order to alleviate this change in chromatic aberration. However, these special glasses also have the characteristics shown in FIG. Therefore, it is difficult to sufficiently reduce the change in chromatic aberration on the short wavelength side.

[0010]

When a primary color filter is used, the amount of light entering each pixel is small. When the size of the pixel becomes small, a problem of an S / N ratio and a problem of an exposure time occur. Further, there is a problem that pixels that affect the resolution are 50% of the effective pixels, and the effect of sufficiently high pixels cannot be fully utilized in image quality.

The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide an optical system capable of reproducing good images including colors with a simple configuration. is there. In particular, it is an object of the present invention to provide an optical system suitable for achieving high pixel count, low cost, and miniaturization of a digital camera.

[0012]

According to the first image pickup apparatus of the present invention which achieves the above object, at least the following conditions are satisfied when the diagonal length of the effective image pickup area is d and the center interval between horizontal pixels is p. An electronic imaging device that satisfies the formula (1) and has a complementary color filter composed of at least four types of color filters, a transmittance at ₄₀₀ nm of T ₄₀₀ , a transmittance of ₆₀₀ nm of T ₆₀₀ , and a transmittance of 700 nm An imaging optical system that has the following spectral characteristics (2) and (3) and guides a light beam from the object side to the electronic imaging device when T ₇₀₀ is set, and performs signal processing based on an output from the electronic imaging device And a controller for performing image processing.

1.0 × 10 ⁻⁴ <p / d <6.0 × 10 ⁻⁴ (1) 8 × T ₇₀₀ <T ₆₀₀ (2) T ₄₀₀ <T ₆₀₀ ( 3) The operation and effect of the first imaging device will be described below.

Conditional expression (1) is a condition for the number of pixels in the horizontal direction for obtaining high image quality. It is said that the resolution of the human eye is particularly high in the horizontal direction. When the value exceeds the upper limit of 6.0 × 10 ⁻⁴ of the conditional expression (1), the image becomes coarse and high image quality cannot be said. In addition, when the upper limit is exceeded, it is less necessary to obtain the effects described later particularly by using other components of the present invention. Exceeding the lower limit of 1.0 × 10 ⁻⁴ in (1) is not desirable because the pixels become too small and the light quantity cannot be sufficiently obtained. Further, the effect of improving image quality cannot be obtained due to the influence of diffraction. Alternatively, the entire image sensor becomes large, and accordingly, the photographing optical system becomes large, which is contrary to miniaturization. Also, the size of the entire image pickup device such as a CCD is C
This has a significant effect on the cost of an imaging device such as a CD, and is undesirable in terms of cost.

In addition, by using a complementary color filter, the amount of light per unit area can be secured. 4
The color filters of so-called magenta (M), cyan (C), yellow (Y _e ), and green (G) include cyan (C), yellow (Y _e ), and green (G). Green (light in a wavelength range of about 500 nm to 550 nm), which is a major factor in determining the resolution of an image
, At least 75% of the effective pixels greatly affect the resolution, and the effect of increasing the number of pixels presented by the conditional expression (1) can be sufficiently obtained.

Conditional expression (2) is a condition relating to infrared cut. By satisfying this conditional expression, inevitably 7
The transmittance at 00 nm is 12.5% or less, and an infrared cut effect can be obtained. If the value is outside the range of the conditional expression (2), light in the infrared region which is not recognized as a color by a person has a large effect on the red color development, and also disturbs the exposure balance, making it impossible to reproduce a desirable color.

Conditional expression (3) relates to the influence on the short wavelength side on the color development of red in the complementary color filter.
As described above, when converted from the complementary color filter to R, G, and B, a blue wavelength range (from 400 nm to 43 in FIG. 11).
An output of an R signal (a signal that causes red coloring) is generated for an input of a wavelength range of about 0 nm. When the value exceeds the range of the conditional expression (3), the influence of the input on the short wavelength side with respect to the original red input increases the intensity of the R signal, and the color reproducibility deteriorates. In particular, in the case of a photographing optical system in which chromatic aberration on the short wavelength side is larger than the main visible range, the spread of spots on the short wavelength side which is originally inconspicuous (so-called spherical aberration of color, coma aberration, chromatic aberration of magnification, etc.) Flare caused by
However, the image quality is degraded by emitting a conspicuous red color.

Using a complementary color filter, conditional expression (2):
By satisfying (3), color reproducibility is improved,
In addition, even when using an imaging optical system in which chromatic aberration is large, the flare on the short wavelength side is sufficiently weaker than the image in the visible region, considering the sensitivity of the human eye, which substantially affects the image quality. Is almost gone.

Such a photographing optical system generates a chromatic aberration on the shorter wavelength side than the main visible region, thereby making the size compact, facilitating manufacture, reducing the number of constituent lenses, and reducing the F-number. To increase the angle of view, to increase the angle of view with respect to the standard (in exchange for off-axis chromatic aberration), to decrease the angle of view with respect to the standard (in exchange for on-axis chromatic aberration), or to zoom in the case of a zoom lens The ratio can be increased, and a totally preferable photographing apparatus can be configured.

It should be noted that the complementary colors R, R
Conversion into G and B, gamma correction, and the like can be performed.

The photographing optical system, the electronic image pickup device and the controller need not be integrated. For example, the image pickup optical system is detachable from a device including the electronic image pickup device so that a plurality of image pickup optical systems can be used. You may.

P is 3.9 μm or less, 1.8 μm
It is desirable that this is the case. That is, the upper limit of 3.9 μm
If m is exceeded, the area of the entire electronic imaging device becomes large and the cost increases. If the lower limit of 1.8 μm is exceeded, it becomes difficult to provide a sufficient amount of light for each pixel of the image sensor. Further, p is desirably 3.5 μm or less and 2.1 μm or more. That is, when the upper limit of 3.5 μm is exceeded,
The area of the entire electronic image pickup device increases and the cost increases.
If the lower limit of 2.1 μm is exceeded, it becomes difficult to configure a photographing optical system having chromatic aberration permitted by the configuration of the present invention with a simple configuration or at low cost. Further, p is 3.2 μm
Hereinafter, when the thickness is 2.1 μm or more, the balance is improved.

The second imaging apparatus of the present invention comprises at least
When the diagonal length of the imaging optical system and the effective imaging area is d, and the center distance between horizontal pixels is p, the following conditional expression (1) is satisfied and a complementary color composed of at least four types of color filters is provided. An electronic image pickup device having a filter, transmitted through the photographing optical system, incident on the electronic image pickup device, photoelectrically converted by the electronic image pickup device, and output from the electronic image pickup device, at least one type of color filter. Spectral intensity curve of the output signal of the corresponding system (D ₆₅
Curve source of light is depicted by the intensity of the output signal of each wavelength when it is incident) is the peak of the spectral intensity S _P
When the intensity at ₆₀₀ nm is S ₆₀₀ and the intensity at ₆₅₀ nm is S ₆₅₀ , a controller that satisfies the following condition (4) and performs signal processing and image processing based on the output from the electronic image sensor is provided. It is characterized by having.

1.0 × 10 ⁻⁴ <p / d <6.0 × 10 ⁻⁴ (1) 0.45 <(S ₆₀₀ −S ₆₅₀ ) / S _P <0.85 (( 4) The operation and effect of the second imaging device will be described below.

The condition (1) and the complementary color filter are the same as in the case of the first imaging device.

Conditional expression (4) relates to the infrared cut and the so-called red signal intensity. Within the range of this conditional expression, a red signal of sufficient intensity can be obtained, the influence of the short wavelength region on the red color signal calculated by the controller can be relatively reduced, and the effect of the complementary color filter can be obtained. , And substantially good color reproduction is obtained. Exceeding the lower limit of 0.45 to condition (4) is not preferable because sufficient infrared cuts cannot be made or a red signal with sufficient intensity cannot be obtained. When the value exceeds the upper limit of 0.85 of the conditional expression (4), a color filter, an infrared cut filter, or
It becomes difficult to form a vapor-deposited thin film coating having an infrared cut function, which increases costs and complicates the structure, thereby deteriorating productivity, which is not preferable.

The third imaging apparatus according to the present invention comprises first and second
Is provided with an electronic imaging device having a complementary color filter composed of at least four types of color filters, and the characteristics of the four types of color filters are as follows.

The first color filter G has a peak at a wavelength G _P , the second color filter Y _e has a peak at a wavelength Y _P , and the third color filter C has a peak at a wavelength C _P. The fourth color filter M has a peak and a wavelength M _P1 and a wavelength M _P2.
And the following conditions are satisfied.

[0029] _{510nm <G P <540nm ··· (} 5-1) 5nm <Y P -G P <35nm ··· (5-2) -100nm <C P -G P <-5nm ··· (5 -3) 430 nm <M _P1 <480 nm (5-4) 580 nm <M _P2 <640 nm (5-5) The operation and effect of the third imaging device will be described below.
By satisfying the conditions of (5-1) to (5-5), good color reproduction and green (wavelength from about 500 nm to about 550 nm) in which G, _Ye , and C are large factors that determine the resolution of an image. With sufficient sensitivity to light in the wavelength range of the wavelength range, and a good sense of resolution suitable for high pixels can be obtained.

A fourth imaging apparatus according to the present invention is the third imaging apparatus, further comprising an electronic imaging element having a complementary color filter composed of at least four types of color filters. Each type of color filter has an intensity of 80% or more at a wavelength of 530 nm with respect to the peak of each spectral intensity, and one type of color filter has:
The peak of the spectral intensity is 25 at a wavelength of 530 nm.
% Or more.

The operation and effect of the fourth image pickup apparatus will be described below. By satisfying this configuration, it is possible to extract information having an effect on the resolution from all color filters.

According to a fifth image pickup apparatus of the present invention, in the first to fourth image pickup apparatuses, an electronic image pickup device having a complementary color filter composed of at least four types of color filters is provided. Are arranged in a mosaic so that each pixel has substantially the same number and adjacent pixels do not correspond to the same type of color filter.

The operation and effect of the fifth image pickup apparatus will be described below.
This is preferable because color reproducibility and resolution of each color are improved, and the overall image quality is improved.

According to a sixth imaging apparatus of the present invention, in the first to fifth imaging apparatuses, the object is located at a position closer to the object side than the electronic imaging device.
The transmittance at 0 nm is 80% or more, and the transmittance at 700 nm is 1
The optical element is characterized by having an optical element coated with a deposited thin film having a characteristic of 0% or less.

The operation and effect of the sixth imaging device will be described below. With such a configuration, the characteristics of the first and second imaging devices can be reduced with a simple configuration and at low cost. It is possible to configure an imaging device having the same. That is, 700n
The so-called infrared cut function of cutting a light beam of m or more can be realized by combining an infrared cut filter and a vapor-deposited thin film coat of a plurality of lenses constituting a photographic optical system. However, with such a configuration, 600 nm
Is also reduced. In order to ensure a sufficient transmittance of 600 nm and to obtain a sufficient red input signal, it is desirable to obtain the above-mentioned characteristics by one-sided evaporation thin film coating.

According to this method, since the portion that performs the main function of infrared cut is thin, the reduction in the overall transmittance is reduced, and the size of the photographing apparatus can be reduced. Also,
By reducing the number of sites that need to be carefully managed with respect to infrared cut, productivity such as yield can be improved, and costs can be reduced, which is preferable.

It is more preferable to have an optical element coated with a vapor-deposited thin film having a transmittance of not less than 90% at 600 nm and not more than 10% at 700 nm.

A seventh imaging apparatus according to the present invention is characterized in that, in the first to sixth imaging apparatuses, the imaging optical system has an effective diagonal screen having an area of 70 ° or more.

The operation and effect of the seventh image pickup apparatus will be described below. When the effective diagonal angle of view is 70 ° or more, chromatic and chromatic coma of magnification, which are off-axis aberrations, are likely to occur. ADVANTAGE OF THE INVENTION According to this invention, it is a high-quality imaging | photography which has a feeling of resolution and can reproduce a good color, without taking a complicated structure especially, or the structure which reduces or does not use a special optical element or expensive material. The device can be realized. It should be noted that the present invention naturally includes a zoom photographing optical system whose wide-angle end has an effective diagonal angle of view of 70 ° or more.

An eighth imaging apparatus according to the present invention is characterized in that, in the first to sixth imaging apparatuses, the imaging optical system has an area having an effective diagonal angle of view of 12 ° or less.

The operation and effect of the eighth image pickup apparatus will be described below. When the effective diagonal angle of view is 12 ° or less, the ratio of the difference in focal length depending on the wavelength tends to increase, and the color which is an axial aberration Tends to cause spherical aberration. ADVANTAGE OF THE INVENTION According to this invention, it is a high-quality imaging | photography which has a feeling of resolution and can reproduce a good color, without taking a complicated structure especially, or the structure which reduces or does not use a special optical element or expensive material. The device can be realized. Incidentally, the present invention naturally includes a zoom photographing optical system in which the wide-angle end has an effective diagonal angle of view of 12 ° or less.

A ninth imaging apparatus according to the present invention is characterized in that, in the first to sixth imaging apparatuses, a photographic optical system having an area where the F value is brighter than 2.8 is provided.

The function and effect of the ninth image pickup apparatus will be described below. By increasing the F value, a sufficient light intensity can be obtained even if the pixel pitch is small. If the F-number is brighter than 2.8, chromatic spherical aberration and chromatic coma tend to occur. ADVANTAGE OF THE INVENTION According to this invention, it is a high-quality imaging | photography which has a feeling of resolution and can reproduce a good color, without taking a complicated structure especially, or the structure which reduces or does not use a special optical element or expensive material. The device can be realized. The present invention naturally includes a zoom photographing optical system in which the F value at the wide-angle end is brighter than 2.8.

The tenth imaging apparatus according to the present invention comprises first to sixth
An imaging optical system having, in order from the object side, a positive first lens group, a negative second lens group movable at the time of zooming, and a lens group having a focusing function on the image side. It is characterized by having.

The operation and effect of the tenth imaging device will be described below. On-axis luminous flux incident on the positive first lens unit from the object side is incident on the negative second lens unit while converging.
That is, the diameter of the second lens group can be reduced. By this effect, the power of the second lens group can be easily increased, and it becomes easy to increase the zoom ratio and brighten the F-number. At this time, the power of the first lens group is correspondingly strong, and chromatic aberration of higher magnification is likely to occur. In addition, when the zoom ratio is increased, the fluctuation of the higher-order chromatic aberration of magnification increases due to zooming, and the effect is particularly large when the number of pixels is increased as defined by the conditional expression (1). Also,
Regarding axial chromatic aberration, chromatic aberration due to the secondary spectrum cannot be completely removed, especially on the telephoto side. As for the aberration of the reference wavelength other than the so-called chromatic aberration, a sufficient configuration can be achieved with a relatively small number of sheets and an inexpensive material by performing correction within each group and correction between groups. By providing the characteristics described for the first and second imaging devices, the chromatic aberration can be reduced without increasing the size of the complicated configuration and imaging optical system, and using many special optical elements and expensive materials. Without
Particularly, even if the aberration on the short wavelength side is relatively large, a substantial image quality can be obtained satisfactorily. By arranging a lens group having a focusing function on the image side of the second lens group, a space for focusing is advantageous, and particularly in a photographing optical system corresponding to an electronic image pickup device in which an exit pupil is set far. Advantageously, the image is less deteriorated due to the change in the object point distance.

An eleventh image pickup apparatus according to the present invention is the image pickup apparatus according to the tenth image pickup apparatus, wherein, in order from the object side, a positive first lens unit,
A movable negative second lens group, a positive third lens group during zooming,
An image pickup optical system comprising a fourth lens group movable at the time of zooming and having a focusing function is provided.

The operation and effect of the eleventh image pickup apparatus will be described below. By arranging the positive third lens group, the light incident on the electronic image pickup element is made almost perpendicular to the pixel, that is, This makes it easy to set the exit pupil far. Desirably, the aperture stop is set to the second lens group and the third lens group.
It is good to arrange between lens groups. This facilitates a configuration in which the exit pupil is set farther.

According to a twelfth imaging apparatus of the present invention, in the eleventh imaging apparatus, a positive first lens group,
Negative second lens group movable at the time of zooming, positive third lens group movable at the time of zooming, positive fourth lens movable at the time of zooming and having a focusing function
It has an imaging optical system composed of a lens group.

The operation and effect of the twelfth image pickup apparatus will be described below. By making the positive third lens group movable, it is possible to bear the zooming effect of the second lens group. It is easy to improve the zoom ratio and brighten the F value. By making the fourth lens group have positive power, the function of making the exit pupil of the third lens group far can be shared, and the zooming function of the third lens group can be enhanced.

A thirteenth imaging device according to the present invention is the eleventh imaging device, wherein, in order from the object side, a positive first lens unit,
A movable second negative lens group at the time of zooming, and a positive third lens group as a whole including at least a positive lens and a negative lens on the image side and a positive power on the image side for focusing It is characterized by having an imaging optical system comprising a lens group having a function.

The operation and effect of the thirteenth imaging apparatus will be described below. The principal point is set forward by setting the configuration of the third lens unit to be positive or negative, and the positive lens unit is moved to the image side. By arranging, the total length can be reduced.

A fourteenth imaging apparatus according to the present invention is the same as the thirteenth imaging apparatus, except that the positive first lens unit,
A third lens as a whole, including a negative second lens group movable at the time of zooming and including at least a positive lens on the image side and a negative lens having a concave surface with a strong curvature on the image side. An image pickup optical system comprising a group and a lens group having a focusing function on an image side thereof is characterized in that the image pickup optical system includes:

The function and effect of the fourteenth imaging apparatus will be described below. The positive lens, the subsequent positive lens from the object side of the third lens group, and the negative lens having a concave surface with a strong curvature on the image side are arranged on the axis. This layout is effective for correcting upper light flux and off-axis coma.

By configuring the fourth lens group to start with a negative lens and a positive lens from at least the object side,
The third lens group and the fourth lens group have a substantially double Gaussian layout, and even if the F value is made bright, it is easy to configure good performance.

By constructing the fourth lens group with one positive lens, the overall length can be shortened (because the axial luminous flux converges substantially uniformly in the fourth lens group).

According to a fifteenth imaging apparatus of the present invention, in the fourteenth imaging apparatus, a positive first lens unit, in order from the object side,
A positive lens having a negative second lens group movable at the time of zooming and having an aspherical surface on the image side, and a positive lens and a negative lens having a concave surface with a stronger curvature on the image side than on the object side. And an imaging optical system including a positive third lens group as a whole including at least the cemented component and a lens group having a focusing function on the image side.

The function and effect of the fifteenth imaging device will be described below. Higher-order spherical aberration is mainly corrected by arranging an aspheric surface on the object-side positive lens of the third lens unit. It is preferable to dispose an aspherical surface on the image side of the positive lens, since the selection of the curvature of the lens can easily bring out the effect of the aspherical surface. The subsequent positive lens and negative lens with a concave surface with a stronger curvature on the image side than on the object side are also effective layouts for correcting on-axis luminous flux and off-axis coma. As a result, the factor of image quality deterioration due to eccentricity occurring between the positive lens and the negative lens is greatly reduced.

By configuring the fourth lens group to start with a negative lens and a positive lens from at least the object side,
The third lens group and the fourth lens group have a substantially double Gaussian layout, and even if the F value is made bright, it is easy to configure good performance.

Further, by forming the fourth lens group with one positive lens, the overall length can be shortened (because the axial luminous flux converges substantially uniformly in the fourth lens group).

The sixteenth imaging apparatus according to the present invention comprises first to sixth
The image pickup apparatus includes, in order from the object side, a negative first lens group movable at the time of zooming and a positive second lens group movable at the time of zooming, and a focusing function on the second lens group or the image side thereof. And an imaging optical system having a certain lens group.

The function and effect of the sixteenth image pickup apparatus will be described below.
The arrangement of the lens groups tends to increase the diameter of the second lens group, but has the effect of lowering the incident height of the off-axis light flux of the first lens group, and has a relatively low magnification zoom lens of up to about three times. And wide-angle zoom lenses. Further, since the diameter of the first lens group is easily reduced, there is an effect that the configuration length of the first lens group is shortened and the size of the photographing apparatus when stored is reduced. In order to bring out this effect, it is necessary to reduce the number of lens components of the first lens group. (A small number of components contributes to shortening of the component length by itself, but the object side of the first lens group is reduced. This also has the effect of reducing the lens diameter and the effect of shortening the configuration length per lens.) On the other hand, when the number of components of the first lens group is reduced, a higher-order component of chromatic aberration at the magnification at the wide-angle end is particularly likely to occur. By providing the characteristics described with respect to the first imaging device and the second imaging device, the chromatic aberration can be reduced without increasing the size of the complicated configuration and the imaging optical system, and by using special optical elements and expensive materials. , And substantial image quality can be obtained satisfactorily even if the aberration on the short wavelength side is relatively large.

Further, by providing the second lens group or a group following it with a focusing function, a quick focusing can be performed.

A seventeenth imaging apparatus according to the present invention is the sixteenth imaging apparatus according to the sixteenth imaging apparatus, wherein, in order from the object side, the lens which is movable at the time of zooming and is closest to the object side is a negative lens, and a negative first lens group and an aspherical surface. A positive lens having at least a cemented component of a positive lens and a negative lens having a concave surface with a stronger curvature on the image side than on the object side, and including a second positive lens group movable as a whole during zooming. And an imaging optical system having the second lens group or a lens group having a focusing function on the image side of the second lens group.

The operation and effect of the seventeenth image pickup apparatus will be described below. With this configuration, the principal point is located on the front side, and the zooming between the first lens group and the second lens group is performed. The effect of securing space is obtained, and it corrects particularly high-order spherical aberration and coma aberration with an aspheric surface, and the negative lens with a concave surface with strong curvature on the image side is particularly effective at correcting aberration of off-axis light flux. Obtainable. Thus, with the positive lens,
The following positive lens and negative lens with a concave surface with a stronger curvature on the image side than on the object side are also effective layouts for correcting on-axis luminous flux and off-axis aberrations. As a result, the factor of image quality deterioration due to eccentricity occurring between the positive lens and the negative lens is greatly reduced.

Further, by disposing a positive single lens having a strong curvature on the fixed image side during zooming on the image side of the second lens group, it is effective in correcting off-axis coma and the like and in disposing the exit pupil. It is a target. Further, by arranging the aperture stop between the first lens group and the second lens group, the exit pupil can be effectively arranged.

An eighteenth imaging apparatus according to the present invention is the imaging apparatus according to the seventeenth imaging apparatus, wherein, in order from the object side, the first lens group which is movable at the time of zooming and which is closest to the object side is a negative lens as a whole; A positive lens having at least a cemented component of a positive lens and a negative lens having a concave surface with a strong curvature on the image side, including a second positive lens group that is movable as a whole during zooming, The image pickup apparatus further comprises a lens group having a focusing function on the image side, and an imaging optical system satisfying the following conditions.

−β _T > 1.2 (6) where β _T is the magnification of the second lens unit at the telephoto end.

The function and effect of the eighteenth imaging device will be described below. Conditional expression (6) is a conditional expression for effectively shortening the length of each group. Deviating from equation (6),
The power of the first lens group is increased, and as a result, the number of lens components increases, and the component length increases.

The lens layouts after the tenth image pickup device mainly take into consideration the aberration of the reference wavelength and the paraxial arrangement, and have a simpler configuration than the synergistic effect with the first and second image pickup devices. It can be seen that high image quality can be obtained with a low-cost configuration or a compact configuration.

The specific chromatic aberration level is described below. By configuring the optical system so that the chromatic aberration at the meridional section with a wavelength of 400 nm when focusing on an object point at infinity within a range of 70% of the effective screen becomes 4 pixels or more, the wavelength range related to image formation is formed. An optical system that improves image performance can be provided with a simple configuration. Here, the chromatic aberration in the meridional section is 4 pixels, in a state where the image pickup apparatus focuses on the object point at infinity (that is, a state where the autofocus mechanism focuses on the object point at substantially infinity, or In a state in which focusing is performed on an object point at infinity in accordance with an infinite memory with manual focus, or a d-line (587.6 nm) on the optical axis with respect to an object point at infinity on the optical axis PSF (Point Spread
Function) In the state where the peak of the intensity is maximized), the dimension δ on the meridional section within a range of 1.6% or more of the maximum value of the PSF intensity at a specific wavelength is defined as chromatic aberration. At its wavelength 400 nm, its dimension δ (40
0) has a configuration of four or more pixels.

The range of 70% of the effective screen is defined as a circle having a radius of 0.7 times the maximum effective image height from the center of the imaging surface when the distance from the center of the imaging surface to the maximum effective image height is 1. Say inside.

Further, the chromatic aberration at a wavelength of 435 nm to 600 nm is within three pixels within a range of 70% of the effective screen. With this configuration, it is possible to provide an imaging optical system in which a change in imaging performance due to wavelength has no practical problem.

Further, instead of the above configuration, the effective diagonal length of the electronic image pickup device is d, the chromatic aberration at a wavelength of 400 nm in the range of 70% of the effective screen defined above is δ (400), and the chromatic aberration at a wavelength of 420 nm is Is defined as δ (420), it is preferable that δ (400) / d> 2.0 × 10 ⁻³ is satisfied.

Further, it is preferable that δ (420) / d <1.5 × 10 ⁻³ is satisfied.

Although the chromatic aberration has been discussed for the wavelengths of 400 nm and 420 nm, the chromatic aberration of the h-line (404.7 nm) and the wavelength of 42
The same effect can be obtained by replacing the chromatic aberration at 0 nm with the chromatic aberration at g-line (435.8 nm).

Focusing on the chromatic aberration of magnification, the distance between the peak of the d-line spot and the peak of the g-line spot at the center vest of the d-line is preferably 7 pixels or less over the entire effective screen of the electronic image pickup device. Further, it is preferable that the distance between the d-line and the h-line includes a position of 10 pixels or more.

Alternatively, when the distance between the peaks of the d-line and the h-line is defined as Δdh, the distance between the peaks of the d-line and the g-line is defined as Δdg, and the effective diagonal length of the electronic image sensor is defined as d, It is preferable that Δdh / d> 6.0 × 10 ⁻³ is satisfied at least in part.

Further, it is preferable that Δdg / d <4.5 × 10 ⁻³ is satisfied over the entire screen.

[0079]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments and examples of an image pickup apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a so-called digital camera 10. The luminous flux having emitted an object point is subjected to an image-forming action by a photographing lens system 1 composed of an optical element, and forms an image on an image sensor 3 such as a CCD. At this time, the filter 2 having a low-pass effect is disposed on the object side with respect to the imaging surface 3 in order to prevent a so-called moiré phenomenon caused by the imaging element 3 being a regular collection of photoelectric conversion elements. Further, a filter having an IR cut effect for cutting infrared light may be arranged. The light beam incident on the image sensor 3 is converted into an electric signal by the photoelectric conversion element and is input to the controller 4. Signal processing such as gamma correction and image compression processing is performed by the controller 4, and output to the personal computer 8 or the like via the built-in memory 5 or the interface 7. Controller 4
Can be communicated to the liquid crystal monitor 6 so that the photographer can confirm the image to be photographed or the photographed image. Further, image data can be communicated from the built-in memory 5 to an auxiliary memory 9 such as a so-called smart media (trademark).

At this time, when the diagonal length of the effective image pickup area is d and the center distance between the horizontal pixels is p, the image pickup device 3 satisfies the following conditional expression and includes at least four types of color filters. It has a complementary color filter.

1.0 × 10 ⁻⁴ <p / d <6.0 × 10 ⁻⁴ (1) The transmittance of the imaging lens system 1 and the filter 2 together satisfies the following conditional expression. ing. That is, 400 nm
T ₆₀ the transmittance of T _400, 600 nm the transmittance of _0, 70
When the transmittance of 0nm was T _700, to satisfy the _{8 × T 700 <T 600 ···} (2) T 400 <T 600 ··· (3).

Alternatively, the output signal from the image sensor 3 has the following characteristics. That is, a spectral intensity curve of an output signal of a system corresponding to at least one type of color filter (a curve drawn by the intensity of the output signal of each wavelength when light of each wavelength is incident on the imaging optical system).
But the peak of the spectral intensity and S _P, when the intensity of 600nm to the intensity of the S _600, 650 nm and _{S 650, 0.45 <(S 600} -S 650) / S P <0.85 ··· (4) The system is configured as follows.

A color filter having a filter arrangement as shown in FIG. This is a type called a complementary color mosaic filter, which is cyan (C), magenta (M), yellow (Y _e ), and green (G).
Are arranged in approximately the same amount. FIG. 5 shows an example of each wavelength characteristic. As described above, in the case of a complementary color filter, the following processing is performed by the controller 4, and the luminance signal Y = | G + M + _Ye + C | * 1/4 color signal RY = | (M + _Ye )-(G + C) | B −Y = | (M + C) − (G + Y _e ) | The complementary color filter can increase the amount of light to the photoelectric conversion surface.

In these embodiments, the filter 2
In addition, a vapor-deposited thin film coat having an infrared cut function as shown in FIG. FIG. 7 shows the standard light source D ₆₅ having the spectral characteristics shown in FIG. 12, the transmittance of the taking lens system 1 as shown in FIG. 13, the infrared cut filter shown in FIG. 6, and the characteristics of the complementary color filter shown in FIG. This shows the characteristics obtained by combining. FIG. 8 shows R, G, B calculated from FIG.
3 shows a signal intensity distribution for color development. For reference, FIG.
An example of the characteristics of a general infrared cut filter is shown. This is an example of a commonly used absorption type infrared cut filter. FIG. 10 shows characteristics obtained by combining the transmittance of the standard light source D ₆₅ and the photographing lens system 1 and the characteristics of the infrared cut filter and the complementary color filter using the light source. Also, FIG.
5 shows signal intensity distributions for R, G, and B color development calculated from.

When FIG. 8 is compared with FIG. 11, it can be seen that the intensity of the R signal at around 430 nm is particularly weak and the intensity around 620 nm is particularly strong. In addition, 450 of the B signal
It can be seen that the intensity around nm is strong. That is, red is reddish and blue is blue. Further, in addition to the fact that the flare caused by the chromatic aberration on the short wavelength side is originally low in energy, in FIG. It has become something. In other words, on a substantial screen having a large amount of information on the subject, the flare information on the short wavelength side does not significantly affect the image quality.

Further, as shown in FIG. 14, as a form different from that of FIG. 1, a so-called light beam is split by a half mirror prism 12 on the object side from the image sensor 3 and the split light beam is guided to a finder optical system 13. There is also a TTL finder format. This type has a feature that power consumption can be reduced and a subject can be observed. The present invention may be applied to such a type.

The infrared cut filter function of the present invention may be added to the characteristics of the complementary color filter itself.

As another embodiment, as shown in FIG. 15, the main body including the photographing lens system 1 and the image pickup device 3 may be made detachable. As the mount section 15, a screw type, a bayonet type, or the like is used. At this time,
The taking lens system 1 may have the infrared cut function of the present invention, or the main body including the image sensor 3 may have the infrared cut function of the present invention.

Of course, the imaging device of the present invention can be applied to a mobile phone, a notebook personal computer, and the like having the imaging device in addition to the digital camera.

Next, Examples A to G of the optical system suitable for the embodiment of the present invention as described above will be described. Some of these embodiments include or do not include a filter, but may be arranged as needed.

FIGS. 16 to 18 are sectional views including the optical axis of Examples A to C, respectively. 19 to 22 show sectional views of Examples D to G including the optical axis at the wide-angle end, respectively. Examples A to C are lens systems having a fixed focal length, and Examples D to G are zoom lens systems having a variable focal length. In the figure, F indicates a filter and prisms, and I indicates an image plane. In the embodiment B, the reflection member R is disposed in the imaging optical system and is suitable for thinning the camera. However, the reflection characteristic of the reflection member R is configured to satisfy the infrared cut function of the present invention. Is also good. Embodiment D is suitable for a so-called TTL finder format.

Hereinafter, the lens configuration of each embodiment will be described.

In Embodiment A, as shown in FIG. 16, a positive meniscus lens having a convex surface facing the object side, a negative meniscus lens having a convex surface facing the object side, a stop, and a biconvex lens formed by combining a biconcave lens with a biconvex lens And a four-group, five-element configuration of biconvex lenses. The aspherical surface is used as one surface on the object side of the biconvex lens closest to the image plane.

In Embodiment B, as shown in FIG. 17, a negative meniscus lens having a convex surface facing the object side, a reflecting surface R for bending the optical path, a diaphragm, a biconvex lens, and a biconcave lens having a biconcave lens It is a four-group, five-element configuration including a cemented lens and a positive lens with a strong convex surface facing the image plane side. Also, the aspheric surface is
One surface is used for the biconvex lens after the stop, and one surface for the positive lens closest to the image plane is used for a total of two surfaces.

In Example C, as shown in FIG. 18, two negative meniscus lenses having convex surfaces facing the object side, a convex lens, an aperture, and a cemented lens formed by combining a biconcave lens with a biconvex lens,
It is composed of 6 groups of 5 biconvex lenses. The aspherical surface is 2
One surface of the second negative meniscus lens and one surface of the biconvex lens closest to the image surface are used for a total of two surfaces.

In Example D, as shown in FIG. 19, the first group G1 includes a cemented lens of a negative meniscus lens having a convex surface facing the object side, a positive meniscus lens having a convex surface facing the object side, and a cemented lens having a convex surface facing the object side. The second group G2 includes a negative meniscus lens having a convex surface facing the object side, a biconcave lens, and a positive meniscus lens having a biconcave lens and convex surface facing the object side. The third group G3 includes a positive meniscus lens having a convex surface facing the object side, a biconvex lens, and a negative meniscus lens having a convex surface facing the object side. The fourth unit G4 includes four cemented lenses of a negative meniscus lens having a convex surface facing the image surface side, a positive meniscus lens having a convex surface facing the image surface side, and two biconvex lenses. .
The aspherical surface is used for the object-side surface of the biconvex lens of the third group G3 and the one lens closest to the image plane of the fourth group G4, for a total of two surfaces. At the time of zooming from the wide-angle end to the telephoto end, the first group G1 and the stop S are fixed and the second group G
2 moves from the object side to the image plane side, and the third group G3 and the fourth group G
Reference numeral 4 moves from the image plane side to the object side.

In Example E, as shown in FIG. 20, the first group G1 is composed of one convex lens, and the second group G2 is composed of a negative meniscus lens having a convex surface facing the object side, a biconcave lens and an object side lens. The third lens unit G3 is composed of a cemented lens formed by a positive meniscus lens having a convex surface facing the lens surface, and a stop S located thereafter. The third group G3 includes a biconvex lens, a positive meniscus lens having a convex surface facing the object side, and a convex surface facing the object side. The fourth group G4 is composed of a single biconvex lens.
Further, the aspheric surface has one lens on the most object side lens of the third group G3.
The surface and the surface closest to the object in the fourth group G4 are used. At the time of zooming from the wide-angle end to the telephoto end, the first group G1 and the aperture S are fixed, the second group G2 moves from the object side to the image plane side, and the third group G3 And the fourth unit G4 move from the image plane side to the object side while widening the mutual distance.

In Example F, as shown in FIG. 21, the first group G1 is composed of one positive lens having a convex surface facing the object side.
The second group G2 includes a negative meniscus lens having a convex surface facing the object side, a biconcave lens, and a positive lens having a strong convex surface facing the object side. After that, the stop S is located.
The fourth group G4 includes a biconvex lens and a negative meniscus lens having a convex surface facing the object side, and the fourth group G4 includes a single positive lens having a strong convex surface facing the image surface side. The aspheric surface is used for one surface on the object side of the fourth unit G4. During zooming from the wide-angle end to the telephoto end, the first group G1 and the stop S are fixed, and the second group G2 moves from the object side to the image plane side, as indicated by the arrow in the figure.
The group G3 and the fourth group G4 move from the image plane side to the object side.

In Example G, as shown in FIG. 22, the first group G1 is composed of two negative meniscus lenses having a convex surface facing the object surface and a positive meniscus lens having a strong convex surface on the object surface. The stop S is located on the object side of the group G2, and the second group G
Reference numeral 2 denotes a biconvex lens, a positive meniscus lens having a strong convex surface on the object surface, and a negative meniscus lens having a strong concave surface on the image side, and the third group G3 includes a positive meniscus lens having a strong convex surface on the image side. I have. The aspherical surface is used for two surfaces, the surface closest to the object in the second group G2 and the image side surface of the single lens in the third group G3. During zooming from the wide-angle end to the telephoto end, the third group G3 is fixed as shown by the arrow in the figure.
The first group G1 temporarily moves to the image side and then takes a convex trajectory on the image side moving to the object side. The second group G2 moves from the image side to the object side integrally with the stop S.

The numerical data of each of the above embodiments are shown below. In addition to the symbols, f is the focal length of the entire system, F _NO is the F number (F value), and 2ω is the angle of view (effective diagonal angle of view). ), P is the pixel pitch, r ₁ , r ₂ ... Are the radii of curvature of each lens surface, d ₁ ,
d ₂ ... the spacing between the lens surfaces, n _d1, n _d2 ... d-line refractive index of each lens, n _g1, n _g2 ... is the refractive index of the g-line of each lens, n _h1, n _h2 ... is H-line refractive index of each lens, Δ
θ _RN1 , Δθ _RN2 ... are the values of Δθ _RN of each lens, ν _d1 , ν
_d2 ... are Abbe numbers of the d-line of each lens. The unit of the radius of curvature and the interval is mm. The aspherical shape is represented by the following equation, where x is an optical axis where the traveling direction of light is positive, and y is a direction perpendicular 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 +
A ₁₀ y ¹⁰ + A ₁₂ y ¹² where r is the paraxial radius of curvature, K is the conic coefficient, A ₄ , A ₆ ,
A ₈ , A ₁₀ , and A ₁₂ are the fourth, sixth, eighth, tenth,
It is a twelfth order aspheric coefficient.

[0103] Example _{A f = 5.55mm F NO = 2.88} 2ω = 64.4 ° p = 3.8 μm d = 6.64mm r 1 = 13.9598 d 1 = 2.4200 n d1 = 1.84666 ν d1 = 23.78 r 2 = 56.3701 d 2 = 0.2700 _{r 3 = 7.6185 d 3 = 0.8700} n d2 = 1.48749 ν d2 = 70.21 r 4 = 2.4917 d 4 = 3.3154 r 5 = ∞ ( _{stop) d 5 = 1.0735 r 6 =} -8.2879 d 6 = 0.8000 n d3 = 1.84666 ν d3 _{= 23.78 r 7 = 10.5000 d 7} = 3.7900 n d4 = 1.72916 ν d4 = 54.68 r 8 = -5.2842 d 8 = 0.1500 r 9 = 9.8776 ( _{aspherical) d 9 = 3.3700 n d5 =} 1.56384 ν d5 = 60.67 r 10 = _{-13.3796 d 10 = 2.7100 r 11 =} ∞ d 11 = 2.3200 n d6 = 1.51633 ν d6 = 64.14 r 12 = ∞ d 12 = 1.6000 r 13 = ∞ d 13 = 0.8000 n d7 = 1.51633 ν d7 = 64.14 r 14 = ∞ _{d 14 = 1.0048 r 15 = ∞} ( image _{plane) n g1 = 1.89419 n h1 =} 1.91428 Δθ RN1 = + 0.0174 n g2 = 1.49596 n h2 = 1.49898 Δθ RN2 = + 0.0022 n g3 = 1.89419 n h3 = 1.91428 Δθ RN3 = + _{0.0174 n g4 = 1.74570 n h4 =} 1.75173 Δθ RN4 = -0.0086 _{n g5 = 1.57532 n h5 = 1.57947} Δθ RN5 = -0.0031 n g6 = 1.52621 n h6 = 1.52977 Δθ RN6 = -0.0024 n g7 = 1.52621 n h7 = 1.52977 Δθ RN7 = -0.0024 aspherical coefficients ninth surface K = 0 A ₄ = -3.6930 x 10 ^-4 A ₆ = 7.0898 x 10 ^-7 .

[0104] Example _{B f = 9.88 F NO = 2.8} 2ω = 59.12 ° p = 3.9 μm d = 11 r 1 = 42.746 d 1 = 1.80 n d1 = 1.48749 ν d1 = 70.23 r 2 = 9.841 d 2 = 21.36 r 3 = ∞ _{(stop) d 3 = 5.09 r 4 =} 96.670 d 4 = 4.16 n d2 = 1.69350 ν d2 = 53.20 r 5 = -14.943 ( _{aspherical) d 5 = 0.08 r 6 =} 9.051 d 6 = 6.95 n d3 = 1.62041 _{ν d3 = 60.29 r 7 = -33.014} d 7 = 0.98 n d4 = 1.80518 ν d4 = 25.42 r 8 = 5.859 d 8 = 4.21 r 9 = -51.618 d 9 = 5.06 n d5 = 1.58913 ν d5 = 61.28 r 10 = - 7.361 _{(aspherical) d 10 = 1.50 r 11 =} ∞ d 11 = 1.00 n d6 = 1.51633 ν d6 = 64.14 r 12 = ∞ d 12 = 1.60 n d7 = 1.54771 ν d7 = 62.84 r 13 = ∞ n g1 = 1.49596 n _{h1 = 1.49898 Δθ RN1 = + 0.0022} n g2 = 1.70972 n h2 = 1.71566 Δθ RN2 = -0.0081 n g3 = 1.63315 n h3 = 1.63778 Δθ RN3 = -0.0012 n g4 = 1.84729 n h4 = 1.86494 Δθ RN4 = + 0.0158 n g5 = _{1.60103 n h5 = 1.60535 Δθ RN5 =} -0.0018 n g6 = 1.52621 n h6 = 1.52977 Δθ RN6 = -0.0024 _{n g7 = 1.55843 n h7 = 1.56226} Δθ RN7 = -0.0045 aspherical coefficients fifth surface _{K = 0 A 4 = 6.18542 ×} 10 -5 A 6 = 3.07784 × 10 -7 10th surface _{K = 0 A 4 = 4.92151 ×} 10 ^-4 A ₆ = -3.57904 × 10 ^-6 A ₈ = 4.22919 × 10 ^-8 .

Example C f = 4.4182 F _NO = 2.4 2ω = 80.9 ° p = 3.8 μm or 3 μm d = 6.64 r ₁ = 13.2550 d ₁ = 0.9000 n _d1 = 1.60311 ν _d1 = 60.64 r ₂ = 7.0317 d ₂ = 1.0000 r ₃ = 12.0000 _{(aspherical) d 3 = 0.8000 n d2 =} 1.56384 ν d2 = 60.67 r 4 = 4.9103 d 4 = 4.6372 r 5 = 7.9159 d 5 = 1.1424 n d3 = 1.84666 ν d3 = 23.78 r 6 = ∞ d ₆ = 0.5000 r ₇ = ∞ _{(stop) d 7 = 1.8751 r 8 =} -3.7652 d 8 = 1.0000 n d4 = 1.80518 ν d4 = 25.42 r 9 = 8.7546 d 9 = 2.1667 n d5 = 1.72916 ν d5 = 54.68 r 10 = _{-4.8805 d 10 = 0.1500 r 11 =} 10.0186 ( _{aspherical) d 11 = 2.2298 n d6 =} 1.56384 ν d6 = 60.67 r 12 = -8.4667 d 12 = 2.3588 r 13 = ∞ d 13 = 1.9000 n d7 = 1.51633 ν d7 = _{64.14 r 14 = ∞ d 14 =} 0.8000 n d8 = 1.51633 ν d8 = 64.14 r 15 = ∞ d 15 = 1.2000 r 16 = ∞ d 16 = 0.7500 n d9 = 1.48749 ν d9 = 70.23 r 17 = ∞ d 17 = 1.2200 r ₁₈ = ∞ (image plane) n _g1 = 1.61541 n _h1 = 1.61987 Δθ _{RN1 = -0.0019 n g2 = 1.57532 n h2} = 1.57947 Δθ RN2 = -0.0031 n g3 = 1.89419 n h3 = 1.91428 Δθ RN3 = + 0.0174 n g4 = 1.84729 n h4 = 1.86494 Δθ RN4 = + 0.0158 n g5 = 1.74570 n h5 = 1.75173 _{Δθ RN5 = -0.0086 n g6 = 1.57532} n h6 = 1.57947 Δθ RN6 = -0.0031 n g7 = 1.52621 n h7 = 1.52977 Δθ RN7 = -0.0024 n g8 = 1.52621 n h8 = 1.52977 Δθ RN8 = -0.0024 n g9 = 1.49596 n h9 = 1.49898 Δθ _RN9 = + 0.0022 Aspherical surface third surface K = 0 A ₄ = 3.1698 × 10 ^-4 A ₆ = 6.1083 × 10 ^-5 A ₈ = -4.6332 × 10 ^-6 A ₁₀ = -1.4286 × 10 ^-7 The eleventh surface K = 0 A ₄ = −1.0432 × 10 ⁻³ A ₆ = −2.9351 × 10 ⁻⁵ A ₈ = 4.2352 × 10 ⁻⁶ A ₁₀ = −1.8071 × 10 ⁻⁷ .

[0106] Example D f = 9.099 ~ 18.100 ~ 35.998 F NO = 2.008 ~ 2.065 ~ 2.481 2ω = 68.4 ° ~ 35.8 ° ~ 18.6 ° p = 3.5 μm d = 11 r 1 = 74.1213 d 1 = 2.5000 n d1 = 1.84666 _{ν d1 = 23.78 r 2 = 45.2920} d 2 = 7.6976 n d2 = 1.61800 ν d2 = 63.33 r 3 = 200.0000 d 3 = 0.1500 r 4 = 53.6322 d 4 = 5.1636 n d3 = 1.77250 ν d3 = 49.60 r 5 = 160.3763 d 5 = _{(variable) r 6 = 86.4469 d 6 =} 1.8938 n d4 = 1.77250 ν d4 = 49.60 r 7 = 12.9947 d 7 = 6.5582 r 8 = -633.9388 d 8 = 1.3849 n d5 = 1.84666 ν d5 = 23.78 r 9 = 53.5036 d _{9 = 3.0086 r 10 = -70.1852 d} 10 = 1.3000 n d6 = 1.48749 ν d6 = 70.21 r 11 = 19.4251 d 11 = 4.0971 n d7 = 1.80518 ν d7 = 25.42 r 12 = 567.6091 d 12 = ( variable) r ₁₃ = ∞ (stop) d ₁₃ = _{(variable) r 14 = 35.5332 d 14 =} 2.9155 n d8 = 1.84666 ν d8 = 23.78 r 15 = 149.5334 d 15 = 1.9951 r 16 = 23.1874 ( _{aspherical) d 16 = 3.2540 n d9 =} 1.69350 ν _d9 = 53.20 r ₁₇ = _{-136.5790 d 17 = 0.1500 r 18 =} 54.2006 d 18 = 1.1258 n d10 = 1.80518 ν d10 = 25.42 r 19 = 17.2110 d 19 = ( _{Variable) r 20 = -12.6096 d 20 =} 1.1000 n d11 = 1.80518 ν d11 = 25.42 r _{21 = -55.3792 d 21 = 3.1600 n} d12 = 1.61800 ν d12 = 63.33 r 22 = -15.6001 d 22 = 0.1500 r 23 = 74.9447 d 23 = 3.2661 n d13 = 1.61800 ν d13 = 63.33 r 24 = -30.4739 d 24 = 0.1500 _{r 25 = 124.0475 d 25 = 2.5117} n d14 = 1.69350 ν d14 = 53.20 r 26 = -68.0400 ( aspherical) d ₂₆ = _{(variable) r 27 = ∞ d 27 =} 24.0000 n d15 = 1.51633 ν d15 = 64.14 r 28 = ∞ d ₂₈ = 1.0000 r ₂₉ = ∞ d ₂₉ = 1.5700 nd ₁₆ = 1.54771 ν _d16 = 62.84 r ₃₀ = ∞ d ₃₀ = 1.0000 r ₃₁ = ｄ d ₃₁ = 0.8000 n _d17 = 1.51823 ν _d17 = 58.96 r ₃₂ = ｎ n _{g1 = 1.89419 n h1 = 1.91428 Δθ} RN1 = + 0.0174 n g2 = 1.63010 n h2 = 1.63451 Δθ RN2 = + 0.0051 n g3 = 1.79197 n h3 = 1.79917 Δθ RN3 = -0.0092 n g4 = 1.79197 n h4 = 1.79917 Δθ RN4 = - _{0.0092 n g5 = 1.89419 n h5 =} 1.91428 Δθ _{RN5 = + 0.0174 n g6 = 1.49596} n h6 = 1.49898 Δθ RN6 = + 0.0022 n g7 = 1.84729 n h7 = 1.86494 Δθ RN7 = + 0.0158 n g8 = 1.89419 n h8 = 1.91428 Δθ RN8 = + 0.0174 n g9 = 1.70972 n h9 = _{1.71566 Δθ RN9 = -0.0081 n g10 =} 1.84729 n h10 = 1.86494 Δθ RN10 = + 0.0158 n g11 = 1.84729 n h11 = 1.86494 Δθ RN11 = + 0.0158 n g12 = 1.63010 n h12 = 1.63451 Δθ RN12 = + 0.0051 n g13 = 1.63010 n _{h13 = 1.63451 Δθ RN13 = + 0.0051} n g14 = 1.70972 n h14 = 1.71566 Δθ RN14 = -0.0081 n g15 = 1.52621 n h15 = 1.52977 Δθ RN15 = -0.0024 n g16 = 1.55843 n h16 = 1.56226 Δθ RN16 = -0.0045 n g17 = _{1.52915 n h17 = 1.53314 Δθ RN17 =} + 0.0035 Aspheric surface 16th surface K = 0 A ₄ = -1.3659 × 10 ^-5 A ₆ = -5.3156 × 10 ^-9 A ₈ = -2.4548 × 10 ^-11 A ₁₀ = 2.2544 × 10 ^-12 26th surface K = 0 A ₄ = 6.6763 x 10 ^-6 A ₆ = 3.7977 x 10 ^-8 A ₈ = -4.9995 x 10 ^-10 A ₁₀ = 2.3437 x 10 ^-12 .

[0107] Example E f = 6.608 ~ 11.270 ~ 19.098 F NO = 2.03 ~ 2.36 ~ 2.91 p = 3.9 μm or 3.2μm d = 8 r 1 = 36.688 d 1 = 4.14 n d1 = 1.48749 ν d1 = 70.23 r 2 = ∞ d ₂ = _{(variable) r 3 = 21.750 d 3 =} 1.25 n d2 = 1.84666 ν d2 = 23.78 r 4 = 8.054 d 4 = 5.45 r 5 = -27.511 d 5 = 1.00 n d3 = 1.48749 ν d3 = 70.23 r 6 = 10.412 d ₆ = 4.50 n _d4 = 1.84666 ν _d4 = 23.78 r ₇ = 40.550 d ₇ = (variable) r ₈ = ∞ (aperture) d ₈ = (variable) r ₉ = 17.583 (aspherical surface) d ₉ = 3.42 n _{d5 = 1.58913 ν d5 = 61.30 r} 10 = -35.670 d 10 = 0.20 r 11 = 9.390 d 11 = 4.35 n d6 = 1.77250 ν d6 = 49.60 r 12 = 87.943 d 12 = 0.90 n d7 = 1.84666 ν d7 = 23.78 r 13 = 6.609 d ₁₃ = (variable) r ₁₄ = 13.553 _{(aspherical) d 14 = 3.28 n d8 =} 1.58913 ν d8 = 61.30 r 15 = -30.808 n g1 = 1.49596 n h1 = 1.49898 Δθ RN1 = + 0.0022 n g2 = 1.89419 _{n h2 = 1.91428 Δθ RN2 = +} 0.0174 n g3 = 1.49596 n h3 = 1.49898 Δθ R _{N3 = + 0.0022 n g4 = 1.89419} n h4 = 1.91428 Δθ RN4 = + 0.0174 n g5 = 1.60103 n h5 = 1.60535 Δθ RN5 = -0.0018 n g6 = 1.79197 n h6 = 1.79917 Δθ RN6 = -0.0092 n g7 = 1.89419 n h7 = 1.91428 Δθ _RN7 = + 0.0174 _ng8 = 1.60103 n _h8 = 1.60535 Δθ _RN8 = -0.0018 Aspheric surface ninth surface K = 0.000 A ₄ = -4.66054 × 10 ^-5 A ₆ = -1.33346 × 10 ^-6 A ₈ = 6.88261 × 10 ^-8 A ₁₀ = -1.18171 × 10 ^-9 A ₁₂ = 1.21868 × 10 ^-12 14th surface _{K = 0.000 A 4 = -9.93375 ×} 10 -5 A 6 = -9.76311 × 10 -7 A 8 = 3.21037 × 10 -7 A 10 = -1.95172 × 10 -8 A 12 = 3.74139 × 10 - ¹⁰ .

Example F f = 9.000 to 15.590 to 27.000 F _NO = 2.800 to 3.030 to 4.069 2ω = 67.094 ° to 39.462 ° to 23.030 ° p = 6.7 μm or 4 μm d = 11 r ₁ = 44.5137 d ₁ = 4.4000 n _d1 = 1.69680 ν _d1 = 55.53 r ₂ = 137.7320 d ₂ = (variable) r ₃ = 23.5602 d ₃ = 1.6000 nd ₂ = 1.69680 ν _d2 = 55.53 r ₄ = 12.0406 d ₄ = 5.7412 r ₅ = -54.8255 d ₅ = 1.5000 _{n d3 = 1.56384 ν d3 = 60.70} r 6 = 13.6238 d 6 = 3.8135 r 7 = 16.0196 d 7 = 2.2000 n d4 = 1.84666 ν d4 = 23.78 r 8 = 23.3091 d 8 = ( variable) r ₉ = ∞ (stop) d ₉ = _{(variable) r 10 = 31.1300 d 10 =} 6.5179 n d5 = 1.77250 ν d5 = 49.60 r 11 = -15.0403 d 11 = 0.1939 r 12 = -13.3787 d 12 = 0.8893 n d6 = 1.84666 ν d6 = 23.78 r 13 = -65.0570 d ₁₃ = (variable) r ₁₄ = -2370.3961 _{(aspherical) d 14 = 4.3000 n d7 =} 1.49241 ν d7 = 57.66 r 15 = -14.2694 d 15 = ( _{variable) r 16 = ∞ d 16 =} 1.1400 n d8 = 1.54771 ν _d8 = 62.84 r ₁₇ = ∞ d _{1 7 = 0.8100 n d9 = 1.54771 ν} d9 = 62.84 r 18 = ∞ d 18 = 1.0000 r 19 = ∞ d 19 = 1.0000 n d10 = 1.48749 ν d10 = 70.23 r 20 = ∞ d 20 = 1.0000 r 21 = ∞ d 21 = _{0.8000 n d11 = 1.51823 ν d11 =} 58.96 r 22 = ∞ n g1 = 1.71234 n h1 = 1.71800 Δθ RN1 = -0.0082 n g2 = 1.71234 n h2 = 1.71800 Δθ RN2 = -0.0082 n g3 = 1.57532 n h3 = 1.57947 Δθ RN3 = _{-0.0031 n g4 = 1.89419 n h4 =} 1.91428 Δθ RN4 = + 0.0174 n g5 = 1.79197 n h5 = 1.79917 Δθ RN5 = -0.0092 n g6 = 1.89419 n h6 = 1.91428 Δθ RN6 = + 0.0174 n g7 = 1.50320 n h7 = 1.50713 Δθ _{RN7 = + 0.0104 n g8 = 1.55843} n h8 = 1.56226 Δθ RN8 = -0.0045 n g9 = 1.55843 n h9 = 1.56226 Δθ RN9 = -0.0045 n g10 = 1.49596 n h10 = 1.49898 Δθ RN10 = + 0.0022 n g11 = 1.52915 n h11 = 1.53314 Δθ _RN11 = + 0.0035 Aspheric surface coefficient surface 14 K = 0.0000 A ₄ = -7.8946 x 10 ^-5 A ₆ = 3.2441 x 10 ^-8 A ₈ = -1.6090 x 10 ^-9 A ₁₀ = 1.6631 x 10 ^-11 .

[0109] Example G f = 4.5 ~ 8.7 ~12.9 F NO = 2.8 ~ 3.9 ~ 5.0 2ω = 58 ° ~32 ° ~21.9 ° p = 3.0 μm d = 5.0 r 1 = 21.9050 d 1 = 1.0000 n d1 = 1.79952 _{ν d1 = 42.22 r 2 = 5.4876} d 2 = 1.9041 r 3 = 133.8501 d 3 = 0.9000 n d2 = 1.79952 ν d2 = 42.22 r 4 = 12.6430 d 4 = 0.2000 r 5 = 7.5698 d 5 = 1.5775 n d3 = 1.84666 ν d3 _{= 23.78 r 6 = 19.3947 d 6} = ( variable) r ₇ = ∞ _{(stop) d 7 = 1.0000 r 8 =} 11.9178 ( _{aspherical) d 8 = 1.6467 n d4 =} 1.58913 ν d4 = 61.14 r 9 = -11.0083 d 9 _{= 0.3000 r 10 = 3.5308 d 10} = 1.5734 n d5 = 1.72916 ν d5 = 54.68 r 11 = 7.2012 d 11 = 0.5000 n d6 = 1.80518 ν d6 = 25.42 r 12 = 2.5388 d 12 = ( variable) r ₁₃ = -24.9058 d _{13 = 2.0739 n d7 = 1.58913 ν} d7 = 61.14 r 14 = -5.9760 ( _{aspherical) d 14 = 0.5000 r 15 =} ∞ d 15 = 0.8000 n d8 = 1.51633 ν d8 = 61.14 r 16 = ∞ d 16 = 1.8000 n d9 = 1.54771 ν _d9 = 62.84 r ₁₇ = ∞ d ₁₇ = 0.5000 r ₁₈ = _{∞ d 18 = 0.5000 n d10 =} 1.51633 ν d10 = 64.14 r 19 = ∞ d 19 = 1.2000 r 20 = ∞ ( image _{plane) n g1 = 1.82355 n h1 =} 1.83271 Δθ RN1 = -0.0060 n g2 = 1.82355 n h2 = 1.83271 _{Δθ RN2 = -0.0060 n g3 = 1.89419} n h3 = 1.91428 Δθ RN3 = + 0.0174 n g4 = 1.60103 n h4 = 1.60535 Δθ RN4 = -0.0018 n g5 = 1.74570 n h5 = 1.75173 Δθ RN5 = -0.0086 n g6 = 1.84729 n h6 _{= 1.86494 Δθ RN6 = + 0.0158 n} g7 = 1.60103 n h7 = 1.60535 Δθ RN7 = -0.0018 n g8 = 1.52621 n h8 = 1.52977 Δθ RN8 = -0.0024 n g9 = 1.55843 n h9 = 1.56226 Δθ RN9 = -0.0045 n g10 = 1.52621 n _h10 = 1.52977 Δθ _RN10 = -0.0024 Aspheric coefficient 8th surface K = 0.0000 A ₄ = -6.2411 × 10 ^-4 A ₆ = -8.9699 × 10 ^-7 A ₈ = -2.7168 × 10 ^-8 A ₁₀ = 5.6463 × 10 ^-9 14th surface K = 0.0000 A ₄ = 1.3371 × 10 ^-3 A ₆ = -3.0850 × 10 ^-5 A ₈ = 1.0398 × 10 ^-9 A ₁₀ = 1.5028 × 10 ^-7 .

By the way, FIG. 6 used in the image pickup apparatus of the present invention.
As a specific example of a filter having an infrared cut function as shown in FIG. 23, there is an IR cut filter having a 27-layer structure as shown in FIG. The data of the multilayer coating is shown below. This filter is
Al ₂ O ₃ , TiO ₂ , and SiO ₂ were deposited on a substrate made of a parallel flat plate having a refractive index of 1.52 in the following order from the substrate side.
It is formed by laminating layers. The design wavelength λ is 780 nm.

Order of Film Material Film Thickness Relative Film Thickness with respect to λ / 4 Substrate 1 Al ₂ O ₃ 58.96 0.50 2 TiO ₂ 84.19 1.00 3 SiO ₂ 134.14 1.00 4 TiO ₂ 84.19 1.00 5 SiO ₂ 134.14 1.00 6 TiO ₂ 84.19 1.00 7 SiO ₂ 134.14 1.008 TiO ₂ 84.19 1.00 9 SiO ₂ 134.14 1.00 10 TiO ₂ 84.19 1.00 11 SiO ₂ 134.14 1.00 12 TiO ₂ 84.19 1.00 13 SiO ₂ 134.14 1.00 14 TiO ₂ 84.19 1.00 15 SiO ₂ 178.41 1.33 16 TiO ₂ 101.03 1.217 SiO ₂ 167.67 1.25 18 TiO ₂ 96.82 1.15 19 SiO ₂ 147.55 1.05 20 TiO ₂ 84.19 1.00 21 SiO ₂ 160.97 1.20 22 TiO ₂ 84.19 1.00 23 SiO ₂ 154.26 1.15 24 TiO ₂ 95.13 1.13 25 SiO ₂ 160.97 1.20 26 TiO ₂ 99.34 1.27 SiO ₂ 87.19 0.65 air.

The above embodiment and Examples A to G
, The values relating to the conditions (1) to (5-5), and
The values of the other parameters are shown below.

Example A Example B Example B Example C Example D (1) p / d 5.72 × 10 ^-4 3.55 × 10 ^-4 5.72 × 10 ^-4 3.18 × 10 ^-4 or 4.52 × 10 ^-4 Example E Example F Example G 4.88 × 10 ^-4 6.09 × 10 ^-4 6.00 × 10 ^-4 or 4.00 × 10 ^-4 or 3.64 × 10 ^-4 Embodiments (2), (3) (photographing lens 1 and filter 2 _{) T 700 0.02 T 600 0.79 T} 400 0.45 in _{(4) S 600 66% S} 650 7% S P 87% (S 600 -S 650) / S P 0.68 (5-1) G P 532nm (5-2) _{Y P -G P 539-532 = 7nm (} 5-3) C P -G P 505-532 = -27nm (5-4) M P1 455nm (5-5) intensity relative to the peak at M _P2 613 nm 530 nm (color filter _{) Y e M C G 0.96 0.25} 0.80 0.71 FIG. 6 600 nm transmittance of 2% transmission 92% 700 nm transmittance of 0% Figure 23 600 nm transmittance of 96% 700 nm of the chisel.

The above-described image pickup apparatus and image pickup optical system according to the present invention can be constituted, for example, as follows.

[1] When at least the diagonal length of the effective image pickup area is d and the center distance between horizontal pixels is p, the following conditional expression (1) is satisfied, and at least four types of color filters are provided. The following spectral characteristics (2) and (3) are obtained when an electronic image pickup device having a complementary color filter and a transmittance at ₄₀₀ nm is T ₄₀₀ , a transmittance at ₆₀₀ nm is T ₆₀₀ , and a transmittance at 700 nm is T _700. An imaging apparatus comprising: an imaging optical system that guides a light beam from an object side to the electronic imaging element; and a controller that performs signal processing and image processing based on an output from the electronic imaging element.

1.0 × 10 ⁻⁴ <p / d <6.0 × 10 ⁻⁴ (1) 8 × T ₇₀₀ <T ₆₀₀ (2) T ₄₀₀ <T ₆₀₀ ( 3) [2] At least when the diagonal length of the imaging optical system and the effective imaging area is d, and the center interval between horizontal pixels is p, the following conditional expression (1) is satisfied, and at least four types of conditional expressions are satisfied. An electronic imaging device having a complementary color filter composed of a color filter, and transmitted through the imaging optical system and incident on the electronic imaging device, photoelectrically converted by the electronic imaging device, and output from the electronic imaging device, at least one of the spectral intensity curve of the system output signal corresponding to the color filter (curve light illuminant D _65, the imaging optical system is described by the intensity of the output signal of each wavelength when it is incident) is the spectral intensity the peak and S _P, the intensity of the 600 nm S _600,
When the intensity at ₆₅₀ nm is set to S650, the image pickup apparatus satisfies the following condition (4) and includes a controller that performs signal processing and image processing based on an output from the electronic image pickup device.

1.0 × 10 ⁻⁴ <p / d <6.0 × 10 ⁻⁴ (1) 0.45 <(S ₆₀₀ −S ₆₅₀ ) / S _P <0.85 (( 4) [3] The imaging device according to the above 1 or 2, further comprising an electronic imaging device having a complementary color filter composed of at least four types of color filters, and the characteristics of the four types of color filters are as follows. An imaging device characterized by the above-mentioned.

[0118] The first color filter G has a peak at a wavelength G _P, a second color filter Y _e has a peak at a wavelength Y _P, a third color filter C is the wavelength C _P The fourth color filter M has a peak and a wavelength M _P1 and a wavelength M _P2.
And the following conditions are satisfied.

[0119] _{510nm <G P <540nm ··· (} 5-1) 5nm <Y P -G P <35nm ··· (5-2) -100nm <C P -G P <-5nm ··· (5 _{-3) 430nm <M P1 <480nm} ··· (5-4) 580nm <M P2 < the imaging apparatus 640 nm · · · (5-5) [4] above 3, wherein at least 4
An electronic image pickup device having a complementary color filter composed of various types of color filters is provided. Of the four types of color filters, three types of color filters have an intensity of 80% or more at a wavelength of 530 nm with respect to the peak of each spectral intensity. An image pickup apparatus, wherein one type of color filter has an intensity of 25% or more at a wavelength of 530 nm with respect to the peak of the spectral intensity.

[5] The imaging device according to any one of the above items 1 to 4, further comprising an electronic imaging device having a complementary color filter composed of at least four types of color filters, wherein the four types of color filters are respectively Are arranged in a mosaic pattern such that the numbers of pixels are substantially the same, and adjacent pixels do not correspond to the same type of color filter.

[6] The imaging apparatus according to any one of the above [1] to [5], wherein 60
The transmittance at 0 nm is 80% or more, and the transmittance at 700 nm is 1
An imaging device comprising an optical element coated with a deposited thin film having a characteristic of 0% or less.

[7] The imaging apparatus according to any one of the above items 1 to 6, further comprising an imaging optical system having an area having an effective diagonal angle of view of 70 ° or more.

[8] The imaging apparatus according to any one of the above items 1 to 6, further comprising an imaging optical system having an area having an effective diagonal angle of view of 12 ° or less.

[0124]

[9] The imaging device according to any one of the above items 1 to 6, further comprising an imaging optical system having an area where the F value is brighter than 2.8.

[10] The imaging apparatus according to any one of the above items 1 to 6, further comprising, in order from the object side, a first positive lens unit and a second negative lens unit movable during zooming. An image pickup apparatus comprising an image pickup optical system having a lens group having a focusing function on an image side.

[11] In the imaging apparatus according to the above item 10, in order from the object side, the first positive lens unit, the second negative lens unit and the third positive lens unit which are movable at the time of zooming, and the movable first lens unit at the time of zooming. An imaging apparatus comprising an imaging optical system including a fourth lens group having a focusing function.

[12] In the imaging apparatus according to the above item 11, in order from the object side, a positive first lens group, a movable negative second lens group during zooming, a movable positive third lens group during zooming, An imaging apparatus comprising: an imaging optical system including a positive fourth lens group which is movable at the time of zooming and has a focusing function.

[13] The imaging apparatus according to the above item 11, further comprising, in order from the object side, a first positive lens unit and a second negative lens unit movable at the time of zooming.
An imaging apparatus comprising: a third lens group as a whole including at least a negative lens; and an imaging optical system including a lens group having a positive power and a focusing function on an image side thereof.

[14] The imaging apparatus according to the above 13, further comprising, in order from the object side, a first positive lens unit and a second negative lens unit movable at the time of zooming, and a positive lens on the image side. A third lens group as a whole including at least a positive lens and a negative lens having a concave surface having a strong curvature on the image side, and an imaging optical system including a lens group having a focusing function on the image side. Imaging device.

[15] The imaging apparatus according to the above item 14, wherein the first lens unit includes, in order from the object side, a negative second lens unit that is movable during zooming, and has an aspheric surface on the image side. A positive third lens group as a whole including at least a cemented component of a positive lens and a negative lens having a concave surface with a stronger curvature on the image side than on the object side, and a focusing function on the image side; An imaging apparatus comprising an imaging optical system including a certain lens group.

[16] In the imaging apparatus according to any one of the above items 1 to 6, in order from the object side, a movable first negative lens group during zooming and a positive second lens group movable during zooming. An imaging apparatus, comprising: an imaging optical system including the second lens group or a lens group having a focusing function on an image side of the second lens group.

[17] In the image pickup apparatus according to the above item 16, in order from the object side, the lens closest to the object side, which is movable at the time of zooming, is the negative first lens group as a whole, and a positive lens having an aspheric surface; The second lens group includes at least a cemented component of a positive lens and a negative lens having a concave surface with a stronger curvature on the image side than on the object side; Alternatively, an imaging apparatus comprising an imaging optical system having a lens group having a focusing function on the image side.

[18] In the imaging device according to the above item 17, in order from the object side, the lens closest to the object side movable at the time of zooming is the negative first lens group, the positive lens having an aspheric surface as a whole; The zoom lens includes at least a cemented component of a positive lens and a negative lens having a concave surface with a strong curvature on the image side, includes a second lens group that is movable as a whole during zooming, and is generally closer to the image side than the second lens group. An imaging apparatus comprising: a lens group having a focusing function; and an imaging optical system satisfying the following conditions.

−β _T > 1.2 (6) where β _T is the magnification of the second lens unit at the telephoto end.

[0135]

As is apparent from the above description, according to the present invention, an image pickup apparatus and an image pickup optical system capable of reproducing a good image including colors for a wide range of natural subjects with a simple configuration. Can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a digital camera according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a filter arrangement of primary color filters.

FIG. 3 is a diagram showing an example of a filter arrangement of a complementary color filter used in the present invention.

FIG. 4 is a diagram illustrating the wavelength characteristics of FIG. 2;

FIG. 5 is a diagram illustrating the wavelength characteristics of FIG. 3;

FIG. 6 is a diagram showing spectral characteristics of an infrared cut filter used in one embodiment of the present invention.

FIG. 7 is a diagram illustrating the entire spectral characteristic of an imaging optical system including a complementary color filter according to an embodiment of the present invention.

8 is a diagram showing R, G, and B signal intensity distributions calculated from the spectral characteristics of FIG. 7;

FIG. 9 is a diagram illustrating spectral characteristics of a general infrared cut filter.

FIG. 10 is a diagram showing the entire spectral characteristic of the photographing optical system when the infrared cut filter of FIG. 9 is used.

FIG. 11 shows R, G, and B calculated from the spectral characteristics of FIG.
It is a figure showing a signal intensity distribution.

12 is a diagram showing the spectral characteristics of the standard illuminant D _65.

FIG. 13 is a diagram illustrating a spectral transmittance of a photographing lens system according to an embodiment of the present invention.

FIG. 14 is a configuration diagram of a digital camera according to another embodiment of the present invention.

FIG. 15 is a configuration diagram of a digital camera according to another embodiment of the present invention.

FIG. 16 is a sectional view including an optical axis of Example A.

FIG. 17 is a cross-sectional view including an optical axis of Example B.

FIG. 18 is a cross-sectional view including an optical axis of Example C.

FIG. 19 is a sectional view of Example D including the optical axis at the wide-angle end.

FIG. 20 is a sectional view of Example E including an optical axis at a wide-angle end.

FIG. 21 is a cross-sectional view of Example F including an optical axis at a wide-angle end.

FIG. 22 is a cross-sectional view of Example G including an optical axis at a wide-angle end.

FIG. 23 is a diagram showing the spectral transmittance of one specific example of an IR cut filter usable in the present invention.

FIG. 24 is a diagram showing a change in refractive power depending on the wavelength of a single lens whose refractive power is 1 at a wavelength of 550 nm.

FIG. 25 is a diagram illustrating a shift amount of a rear focal position with respect to a wavelength of an optical system including only a general refractive optical element when 500 nm is used as a reference.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photography lens system 2 ... Filter with a low-pass effect 3 ... Image sensor 4 ... Controller 5 ... Built-in memory 6 ... LCD monitor 7 ... Interface 8 ... Personal computer 9 ... Auxiliary memory 10 ... Digital camera 11 ... Color separation prism 12 ... Half mirror Prism 13 Finder optical system 15 Mount part G1 First group G2 Second group G3 Third group G4 Fourth group S ... Aperture F ... Filters and prisms I ... Image surface R ... Reflecting member

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shinichi Mihara 2-43-2 Hatagaya, Shibuya-ku, Tokyo F-term in Olympus Optical Co., Ltd. (reference) 5C065 AA03 BB13 CC01 CC08 CC09 EE05 EE06 EE07 EE12 EE16

Claims (3)

[Claims] When at least the diagonal length of the effective imaging area is d and the center distance between horizontal pixels is p, the following conditional expression (1) is satisfied, and at least four types of color filters are provided. An electronic image sensor having a complementary color filter having a transmittance of ₄₀₀ nm at T ₄₀₀ and a transmittance of 600 nm at T
_600, when the 700nm transmittance was defined as T _700, the following spectral characteristics (2), an imaging optical system for guiding the light beam to have, from the object side to the electronic image pickup element (3), from the electronic image pickup device An image pickup apparatus comprising: a controller that performs signal processing and image processing based on the output of the image pickup apparatus. 1.0 × 10 ⁻⁴ <p / d <6.0 × 10 ⁻⁴ (1) 8 × T ₇₀₀ <T ₆₀₀ (2) T ₄₀₀ <T ₆₀₀ (3) 2. When at least the diagonal length of the imaging optical system and the effective imaging area is d, and the center distance between horizontal pixels is p, the following conditional expression (1) is satisfied, and at least four types of conditional expressions are satisfied. An electronic imaging device having a complementary color filter composed of a color filter, and transmitted through the imaging optical system and incident on the electronic imaging device, photoelectrically converted by the electronic imaging device, and output from the electronic imaging device, at least one of the spectral intensity curve of the system output signal corresponding to the color filter (curve light illuminant D _65, the imaging optical system is described by the intensity of the output signal of each wavelength when it is incident) is the spectral intensity the peak and S _P, S ₆₀₀ the intensity of the 600 nm, 650 nm
When the intensity of S is set to _S650 , the following condition (4) is satisfied, and an image pickup apparatus comprising: a controller that performs signal processing and image processing based on an output from the electronic image pickup device. 1.0 × 10 ⁻⁴ <p / d <6.0 × 10 ⁻⁴ (1) 0.45 <(S ₆₀₀ −S ₆₅₀ ) / S _P <0.85 (4) 3. The image pickup apparatus according to claim 1, further comprising an electronic image pickup device having a complementary color filter composed of at least four types of color filters, wherein characteristics of the four types of color filters are as follows. An imaging device characterized by the above-mentioned. The first color filter G has a peak at a wavelength G _P, a second color filter Y _e has a peak at a wavelength Y _P, a third color filter C is have a peak at a wavelength C _P The fourth color filter M has peaks at the wavelengths M _P1 and M _P2 and satisfies the following conditions. _{510nm <G P <540nm ··· (} 5-1) 5nm <Y P -G P <35nm ··· (5-2) -100nm <C P -G P <-5nm ··· (5-3) _{430nm <M P1 <480nm ··· (} 5-4) 580nm <M P2 <640nm ··· (5-5)